From: Han-Wen Nienhuys <hanwen@xxxxxxxxxx> Reftable is a new format for storing the ref database. It provides the following benefits: * Simple and fast atomic ref transactions, including multiple refs and reflogs. * Compact storage of ref data. * Fast look ups of ref data. * Case-sensitive ref names on Windows/OSX, regardless of file system * Eliminates file/directory conflicts in ref names Further context and motivation can be found in background reading: * Spec: https://github.com/eclipse/jgit/blob/master/Documentation/technical/reftable.md * Original discussion on JGit-dev: https://www.eclipse.org/lists/jgit-dev/msg03389.html * First design discussion on git@vger: https://public-inbox.org/git/CAJo=hJtTp2eA3z9wW9cHo-nA7kK40vVThqh6inXpbCcqfdMP9g@xxxxxxxxxxxxxx/ * Last design discussion on git@vger: https://public-inbox.org/git/CAJo=hJsZcAM9sipdVr7TMD-FD2V2W6_pvMQ791EGCDsDkQ033w@xxxxxxxxxxxxxx/ * First attempt at implementation: https://public-inbox.org/git/CAP8UFD0PPZSjBnxCA7ez91vBuatcHKQ+JUWvTD1iHcXzPBjPBg@xxxxxxxxxxxxxx/ * libgit2 support issue: https://github.com/libgit2/libgit2/issues * GitLab support issue: https://gitlab.com/gitlab-org/git/issues/6 * go-git support issue: https://github.com/src-d/go-git/issues/1059 Signed-off-by: Han-Wen Nienhuys <hanwen@xxxxxxxxxx> --- reftable/LICENSE | 31 ++ reftable/README.md | 19 + reftable/VERSION | 5 + reftable/basics.c | 196 +++++++ reftable/basics.h | 37 ++ reftable/block.c | 401 +++++++++++++++ reftable/block.h | 71 +++ reftable/blocksource.h | 20 + reftable/bytes.c | 0 reftable/config.h | 1 + reftable/constants.h | 27 + reftable/dump.c | 97 ++++ reftable/file.c | 97 ++++ reftable/iter.c | 229 +++++++++ reftable/iter.h | 56 ++ reftable/merged.c | 286 +++++++++++ reftable/merged.h | 34 ++ reftable/pq.c | 114 +++++ reftable/pq.h | 34 ++ reftable/reader.c | 708 +++++++++++++++++++++++++ reftable/reader.h | 52 ++ reftable/record.c | 1107 ++++++++++++++++++++++++++++++++++++++++ reftable/record.h | 79 +++ reftable/reftable.h | 399 +++++++++++++++ reftable/slice.c | 199 ++++++++ reftable/slice.h | 39 ++ reftable/stack.c | 983 +++++++++++++++++++++++++++++++++++ reftable/stack.h | 40 ++ reftable/system.h | 55 ++ reftable/tree.c | 66 +++ reftable/tree.h | 24 + reftable/writer.c | 623 ++++++++++++++++++++++ reftable/writer.h | 46 ++ reftable/zlib-compat.c | 92 ++++ 34 files changed, 6267 insertions(+) create mode 100644 reftable/LICENSE create mode 100644 reftable/README.md create mode 100644 reftable/VERSION create mode 100644 reftable/basics.c create mode 100644 reftable/basics.h create mode 100644 reftable/block.c create mode 100644 reftable/block.h create mode 100644 reftable/blocksource.h create mode 100644 reftable/bytes.c create mode 100644 reftable/config.h create mode 100644 reftable/constants.h create mode 100644 reftable/dump.c create mode 100644 reftable/file.c create mode 100644 reftable/iter.c create mode 100644 reftable/iter.h create mode 100644 reftable/merged.c create mode 100644 reftable/merged.h create mode 100644 reftable/pq.c create mode 100644 reftable/pq.h create mode 100644 reftable/reader.c create mode 100644 reftable/reader.h create mode 100644 reftable/record.c create mode 100644 reftable/record.h create mode 100644 reftable/reftable.h create mode 100644 reftable/slice.c create mode 100644 reftable/slice.h create mode 100644 reftable/stack.c create mode 100644 reftable/stack.h create mode 100644 reftable/system.h create mode 100644 reftable/tree.c create mode 100644 reftable/tree.h create mode 100644 reftable/writer.c create mode 100644 reftable/writer.h create mode 100644 reftable/zlib-compat.c diff --git a/reftable/LICENSE b/reftable/LICENSE new file mode 100644 index 0000000000..402e0f9356 --- /dev/null +++ b/reftable/LICENSE @@ -0,0 +1,31 @@ +BSD License + +Copyright (c) 2020, Google LLC +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + +* Redistributions of source code must retain the above copyright notice, +this list of conditions and the following disclaimer. + +* Redistributions in binary form must reproduce the above copyright +notice, this list of conditions and the following disclaimer in the +documentation and/or other materials provided with the distribution. + +* Neither the name of Google LLC nor the names of its contributors may +be used to endorse or promote products derived from this software +without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/reftable/README.md b/reftable/README.md new file mode 100644 index 0000000000..f527da0380 --- /dev/null +++ b/reftable/README.md @@ -0,0 +1,19 @@ + +The source code in this directory comes from https://github.com/google/reftable. + +The VERSION file keeps track of the current version of the reftable library. + +To update the library, do: + + ((cd reftable-repo && git fetch origin && git checkout origin/master ) || + git clone https://github.com/google/reftable reftable-repo) && \ + cp reftable-repo/c/*.[ch] reftable/ && \ + cp reftable-repo/LICENSE reftable/ && + git --git-dir reftable-repo/.git show --no-patch origin/master \ + > reftable/VERSION && \ + echo '/* empty */' > reftable/config.h + rm reftable/*_test.c reftable/test_framework.* + git add reftable/*.[ch] + +Bugfixes should be accompanied by a test and applied to upstream project at +https://github.com/google/reftable. diff --git a/reftable/VERSION b/reftable/VERSION new file mode 100644 index 0000000000..5d505c6c0a --- /dev/null +++ b/reftable/VERSION @@ -0,0 +1,5 @@ +commit e7c3fc3099d9999bc8d895f84027b0e36348d5e6 +Author: Han-Wen Nienhuys <hanwen@xxxxxxxxxx> +Date: Thu Feb 6 20:17:40 2020 +0100 + + C: use inttypes.h header definitions diff --git a/reftable/basics.c b/reftable/basics.c new file mode 100644 index 0000000000..791dcc867a --- /dev/null +++ b/reftable/basics.c @@ -0,0 +1,196 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#include "basics.h" + +#include "system.h" + +void put_u24(byte *out, uint32_t i) +{ + out[0] = (byte)((i >> 16) & 0xff); + out[1] = (byte)((i >> 8) & 0xff); + out[2] = (byte)((i)&0xff); +} + +uint32_t get_u24(byte *in) +{ + return (uint32_t)(in[0]) << 16 | (uint32_t)(in[1]) << 8 | + (uint32_t)(in[2]); +} + +void put_u32(byte *out, uint32_t i) +{ + out[0] = (byte)((i >> 24) & 0xff); + out[1] = (byte)((i >> 16) & 0xff); + out[2] = (byte)((i >> 8) & 0xff); + out[3] = (byte)((i)&0xff); +} + +uint32_t get_u32(byte *in) +{ + return (uint32_t)(in[0]) << 24 | (uint32_t)(in[1]) << 16 | + (uint32_t)(in[2]) << 8 | (uint32_t)(in[3]); +} + +void put_u64(byte *out, uint64_t v) +{ + int i = 0; + for (i = sizeof(uint64_t); i--;) { + out[i] = (byte)(v & 0xff); + v >>= 8; + } +} + +uint64_t get_u64(byte *out) +{ + uint64_t v = 0; + int i = 0; + for (i = 0; i < sizeof(uint64_t); i++) { + v = (v << 8) | (byte)(out[i] & 0xff); + } + return v; +} + +void put_u16(byte *out, uint16_t i) +{ + out[0] = (byte)((i >> 8) & 0xff); + out[1] = (byte)((i)&0xff); +} + +uint16_t get_u16(byte *in) +{ + return (uint32_t)(in[0]) << 8 | (uint32_t)(in[1]); +} + +/* + find smallest index i in [0, sz) at which f(i) is true, assuming + that f is ascending. Return sz if f(i) is false for all indices. +*/ +int binsearch(int sz, int (*f)(int k, void *args), void *args) +{ + int lo = 0; + int hi = sz; + + /* invariant: (hi == sz) || f(hi) == true + (lo == 0 && f(0) == true) || fi(lo) == false + */ + while (hi - lo > 1) { + int mid = lo + (hi - lo) / 2; + + int val = f(mid, args); + if (val) { + hi = mid; + } else { + lo = mid; + } + } + + if (lo == 0) { + if (f(0, args)) { + return 0; + } else { + return 1; + } + } + + return hi; +} + +void free_names(char **a) +{ + char **p = a; + if (p == NULL) { + return; + } + while (*p) { + free(*p); + p++; + } + free(a); +} + +int names_length(char **names) +{ + int len = 0; + for (char **p = names; *p; p++) { + len++; + } + return len; +} + +/* parse a newline separated list of names. Empty names are discarded. */ +void parse_names(char *buf, int size, char ***namesp) +{ + char **names = NULL; + int names_cap = 0; + int names_len = 0; + + char *p = buf; + char *end = buf + size; + while (p < end) { + char *next = strchr(p, '\n'); + if (next != NULL) { + *next = 0; + } else { + next = end; + } + if (p < next) { + if (names_len == names_cap) { + names_cap = 2 * names_cap + 1; + names = realloc(names, + names_cap * sizeof(char *)); + } + names[names_len++] = strdup(p); + } + p = next + 1; + } + + if (names_len == names_cap) { + names_cap = 2 * names_cap + 1; + names = realloc(names, names_cap * sizeof(char *)); + } + + names[names_len] = NULL; + *namesp = names; +} + +int names_equal(char **a, char **b) +{ + while (*a && *b) { + if (strcmp(*a, *b)) { + return 0; + } + + a++; + b++; + } + + return *a == *b; +} + +const char *error_str(int err) +{ + switch (err) { + case IO_ERROR: + return "I/O error"; + case FORMAT_ERROR: + return "FORMAT_ERROR"; + case NOT_EXIST_ERROR: + return "NOT_EXIST_ERROR"; + case LOCK_ERROR: + return "LOCK_ERROR"; + case API_ERROR: + return "API_ERROR"; + case ZLIB_ERROR: + return "ZLIB_ERROR"; + case -1: + return "general error"; + default: + return "unknown error code"; + } +} diff --git a/reftable/basics.h b/reftable/basics.h new file mode 100644 index 0000000000..0ad368cfd3 --- /dev/null +++ b/reftable/basics.h @@ -0,0 +1,37 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef BASICS_H +#define BASICS_H + +#include "system.h" + +#include "reftable.h" + +#define true 1 +#define false 0 + +void put_u24(byte *out, uint32_t i); +uint32_t get_u24(byte *in); + +uint64_t get_u64(byte *in); +void put_u64(byte *out, uint64_t i); + +void put_u32(byte *out, uint32_t i); +uint32_t get_u32(byte *in); + +void put_u16(byte *out, uint16_t i); +uint16_t get_u16(byte *in); +int binsearch(int sz, int (*f)(int k, void *args), void *args); + +void free_names(char **a); +void parse_names(char *buf, int size, char ***namesp); +int names_equal(char **a, char **b); +int names_length(char **names); + +#endif diff --git a/reftable/block.c b/reftable/block.c new file mode 100644 index 0000000000..ffbfee13c3 --- /dev/null +++ b/reftable/block.c @@ -0,0 +1,401 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#include "block.h" + +#include "system.h" + +#include "blocksource.h" +#include "constants.h" +#include "record.h" +#include "reftable.h" +#include "zlib.h" + +int block_writer_register_restart(struct block_writer *w, int n, bool restart, + struct slice key); + +void block_writer_init(struct block_writer *bw, byte typ, byte *buf, + uint32_t block_size, uint32_t header_off, int hash_size) +{ + bw->buf = buf; + bw->hash_size = hash_size; + bw->block_size = block_size; + bw->header_off = header_off; + bw->buf[header_off] = typ; + bw->next = header_off + 4; + bw->restart_interval = 16; + bw->entries = 0; +} + +byte block_writer_type(struct block_writer *bw) +{ + return bw->buf[bw->header_off]; +} + +/* adds the record to the block. Returns -1 if it does not fit, 0 on + success */ +int block_writer_add(struct block_writer *w, struct record rec) +{ + struct slice empty = {}; + struct slice last = w->entries % w->restart_interval == 0 ? empty : + w->last_key; + struct slice out = { + .buf = w->buf + w->next, + .len = w->block_size - w->next, + }; + + struct slice start = out; + + bool restart = false; + struct slice key = {}; + int n = 0; + + record_key(rec, &key); + n = encode_key(&restart, out, last, key, record_val_type(rec)); + if (n < 0) { + goto err; + } + out.buf += n; + out.len -= n; + + n = record_encode(rec, out, w->hash_size); + if (n < 0) { + goto err; + } + + out.buf += n; + out.len -= n; + + if (block_writer_register_restart(w, start.len - out.len, restart, + key) < 0) { + goto err; + } + + free(slice_yield(&key)); + return 0; + +err: + free(slice_yield(&key)); + return -1; +} + +int block_writer_register_restart(struct block_writer *w, int n, bool restart, + struct slice key) +{ + int rlen = w->restart_len; + if (rlen >= MAX_RESTARTS) { + restart = false; + } + + if (restart) { + rlen++; + } + if (2 + 3 * rlen + n > w->block_size - w->next) { + return -1; + } + if (restart) { + if (w->restart_len == w->restart_cap) { + w->restart_cap = w->restart_cap * 2 + 1; + w->restarts = realloc( + w->restarts, sizeof(uint32_t) * w->restart_cap); + } + + w->restarts[w->restart_len++] = w->next; + } + + w->next += n; + slice_copy(&w->last_key, key); + w->entries++; + return 0; +} + +int block_writer_finish(struct block_writer *w) +{ + int i = 0; + for (i = 0; i < w->restart_len; i++) { + put_u24(w->buf + w->next, w->restarts[i]); + w->next += 3; + } + + put_u16(w->buf + w->next, w->restart_len); + w->next += 2; + put_u24(w->buf + 1 + w->header_off, w->next); + + if (block_writer_type(w) == BLOCK_TYPE_LOG) { + int block_header_skip = 4 + w->header_off; + struct slice compressed = {}; + uLongf dest_len = 0, src_len = 0; + slice_resize(&compressed, w->next - block_header_skip); + + dest_len = compressed.len; + src_len = w->next - block_header_skip; + + if (Z_OK != compress2(compressed.buf, &dest_len, + w->buf + block_header_skip, src_len, 9)) { + free(slice_yield(&compressed)); + return ZLIB_ERROR; + } + memcpy(w->buf + block_header_skip, compressed.buf, dest_len); + w->next = dest_len + block_header_skip; + } + return w->next; +} + +byte block_reader_type(struct block_reader *r) +{ + return r->block.data[r->header_off]; +} + +int block_reader_init(struct block_reader *br, struct block *block, + uint32_t header_off, uint32_t table_block_size, + int hash_size) +{ + uint32_t full_block_size = table_block_size; + byte typ = block->data[header_off]; + uint32_t sz = get_u24(block->data + header_off + 1); + + if (!is_block_type(typ)) { + return FORMAT_ERROR; + } + + if (typ == BLOCK_TYPE_LOG) { + struct slice uncompressed = {}; + int block_header_skip = 4 + header_off; + uLongf dst_len = sz - block_header_skip; + uLongf src_len = block->len - block_header_skip; + + slice_resize(&uncompressed, sz); + memcpy(uncompressed.buf, block->data, block_header_skip); + + if (Z_OK != uncompress_return_consumed( + uncompressed.buf + block_header_skip, + &dst_len, block->data + block_header_skip, + &src_len)) { + free(slice_yield(&uncompressed)); + return ZLIB_ERROR; + } + + block_source_return_block(block->source, block); + block->data = uncompressed.buf; + block->len = dst_len; /* XXX: 4 bytes missing? */ + block->source = malloc_block_source(); + full_block_size = src_len + block_header_skip; + } else if (full_block_size == 0) { + full_block_size = sz; + } else if (sz < full_block_size && sz < block->len && + block->data[sz] != 0) { + /* If the block is smaller than the full block size, it is + padded (data followed by '\0') or the next block is + unaligned. */ + full_block_size = sz; + } + + { + uint16_t restart_count = get_u16(block->data + sz - 2); + uint32_t restart_start = sz - 2 - 3 * restart_count; + + byte *restart_bytes = block->data + restart_start; + + /* transfer ownership. */ + br->block = *block; + block->data = NULL; + block->len = 0; + + br->hash_size = hash_size; + br->block_len = restart_start; + br->full_block_size = full_block_size; + br->header_off = header_off; + br->restart_count = restart_count; + br->restart_bytes = restart_bytes; + } + + return 0; +} + +static uint32_t block_reader_restart_offset(struct block_reader *br, int i) +{ + return get_u24(br->restart_bytes + 3 * i); +} + +void block_reader_start(struct block_reader *br, struct block_iter *it) +{ + it->br = br; + slice_resize(&it->last_key, 0); + it->next_off = br->header_off + 4; +} + +struct restart_find_args { + struct slice key; + struct block_reader *r; + int error; +}; + +static int restart_key_less(int idx, void *args) +{ + struct restart_find_args *a = (struct restart_find_args *)args; + uint32_t off = block_reader_restart_offset(a->r, idx); + struct slice in = { + .buf = a->r->block.data + off, + .len = a->r->block_len - off, + }; + + /* the restart key is verbatim in the block, so this could avoid the + alloc for decoding the key */ + struct slice rkey = {}; + struct slice last_key = {}; + byte unused_extra; + int n = decode_key(&rkey, &unused_extra, last_key, in); + if (n < 0) { + a->error = 1; + return -1; + } + + { + int result = slice_compare(a->key, rkey); + free(slice_yield(&rkey)); + return result; + } +} + +void block_iter_copy_from(struct block_iter *dest, struct block_iter *src) +{ + dest->br = src->br; + dest->next_off = src->next_off; + slice_copy(&dest->last_key, src->last_key); +} + +/* return < 0 for error, 0 for OK, > 0 for EOF. */ +int block_iter_next(struct block_iter *it, struct record rec) +{ + if (it->next_off >= it->br->block_len) { + return 1; + } + + { + struct slice in = { + .buf = it->br->block.data + it->next_off, + .len = it->br->block_len - it->next_off, + }; + struct slice start = in; + struct slice key = {}; + byte extra; + int n = decode_key(&key, &extra, it->last_key, in); + if (n < 0) { + return -1; + } + + in.buf += n; + in.len -= n; + n = record_decode(rec, key, extra, in, it->br->hash_size); + if (n < 0) { + return -1; + } + in.buf += n; + in.len -= n; + + slice_copy(&it->last_key, key); + it->next_off += start.len - in.len; + free(slice_yield(&key)); + return 0; + } +} + +int block_reader_first_key(struct block_reader *br, struct slice *key) +{ + struct slice empty = {}; + int off = br->header_off + 4; + struct slice in = { + .buf = br->block.data + off, + .len = br->block_len - off, + }; + + byte extra = 0; + int n = decode_key(key, &extra, empty, in); + if (n < 0) { + return n; + } + return 0; +} + +int block_iter_seek(struct block_iter *it, struct slice want) +{ + return block_reader_seek(it->br, it, want); +} + +void block_iter_close(struct block_iter *it) +{ + free(slice_yield(&it->last_key)); +} + +int block_reader_seek(struct block_reader *br, struct block_iter *it, + struct slice want) +{ + struct restart_find_args args = { + .key = want, + .r = br, + }; + + int i = binsearch(br->restart_count, &restart_key_less, &args); + if (args.error) { + return -1; + } + + it->br = br; + if (i > 0) { + i--; + it->next_off = block_reader_restart_offset(br, i); + } else { + it->next_off = br->header_off + 4; + } + + { + struct record rec = new_record(block_reader_type(br)); + struct slice key = {}; + int result = 0; + int err = 0; + struct block_iter next = {}; + while (true) { + block_iter_copy_from(&next, it); + + err = block_iter_next(&next, rec); + if (err < 0) { + result = -1; + goto exit; + } + + record_key(rec, &key); + if (err > 0 || slice_compare(key, want) >= 0) { + result = 0; + goto exit; + } + + block_iter_copy_from(it, &next); + } + + exit: + free(slice_yield(&key)); + free(slice_yield(&next.last_key)); + record_clear(rec); + free(record_yield(&rec)); + + return result; + } +} + +void block_writer_reset(struct block_writer *bw) +{ + bw->restart_len = 0; + bw->last_key.len = 0; +} + +void block_writer_clear(struct block_writer *bw) +{ + FREE_AND_NULL(bw->restarts); + free(slice_yield(&bw->last_key)); + /* the block is not owned. */ +} diff --git a/reftable/block.h b/reftable/block.h new file mode 100644 index 0000000000..bb42588111 --- /dev/null +++ b/reftable/block.h @@ -0,0 +1,71 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef BLOCK_H +#define BLOCK_H + +#include "basics.h" +#include "record.h" +#include "reftable.h" + +struct block_writer { + byte *buf; + uint32_t block_size; + uint32_t header_off; + int restart_interval; + int hash_size; + + uint32_t next; + uint32_t *restarts; + uint32_t restart_len; + uint32_t restart_cap; + struct slice last_key; + int entries; +}; + +void block_writer_init(struct block_writer *bw, byte typ, byte *buf, + uint32_t block_size, uint32_t header_off, int hash_size); +byte block_writer_type(struct block_writer *bw); +int block_writer_add(struct block_writer *w, struct record rec); +int block_writer_finish(struct block_writer *w); +void block_writer_reset(struct block_writer *bw); +void block_writer_clear(struct block_writer *bw); + +struct block_reader { + uint32_t header_off; + struct block block; + int hash_size; + + /* size of the data, excluding restart data. */ + uint32_t block_len; + byte *restart_bytes; + uint32_t full_block_size; + uint16_t restart_count; +}; + +struct block_iter { + struct block_reader *br; + struct slice last_key; + uint32_t next_off; +}; + +int block_reader_init(struct block_reader *br, struct block *bl, + uint32_t header_off, uint32_t table_block_size, + int hash_size); +void block_reader_start(struct block_reader *br, struct block_iter *it); +int block_reader_seek(struct block_reader *br, struct block_iter *it, + struct slice want); +byte block_reader_type(struct block_reader *r); +int block_reader_first_key(struct block_reader *br, struct slice *key); + +void block_iter_copy_from(struct block_iter *dest, struct block_iter *src); +int block_iter_next(struct block_iter *it, struct record rec); +int block_iter_seek(struct block_iter *it, struct slice want); +void block_iter_close(struct block_iter *it); + +#endif diff --git a/reftable/blocksource.h b/reftable/blocksource.h new file mode 100644 index 0000000000..f3ad3a4c22 --- /dev/null +++ b/reftable/blocksource.h @@ -0,0 +1,20 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef BLOCKSOURCE_H +#define BLOCKSOURCE_H + +#include "reftable.h" + +uint64_t block_source_size(struct block_source source); +int block_source_read_block(struct block_source source, struct block *dest, + uint64_t off, uint32_t size); +void block_source_return_block(struct block_source source, struct block *ret); +void block_source_close(struct block_source source); + +#endif diff --git a/reftable/bytes.c b/reftable/bytes.c new file mode 100644 index 0000000000..e69de29bb2 diff --git a/reftable/config.h b/reftable/config.h new file mode 100644 index 0000000000..40a8c178f1 --- /dev/null +++ b/reftable/config.h @@ -0,0 +1 @@ +/* empty */ diff --git a/reftable/constants.h b/reftable/constants.h new file mode 100644 index 0000000000..cd35704610 --- /dev/null +++ b/reftable/constants.h @@ -0,0 +1,27 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef CONSTANTS_H +#define CONSTANTS_H + +#define SHA1_SIZE 20 +#define SHA256_SIZE 32 +#define VERSION 1 +#define HEADER_SIZE 24 +#define FOOTER_SIZE 68 + +#define BLOCK_TYPE_LOG 'g' +#define BLOCK_TYPE_INDEX 'i' +#define BLOCK_TYPE_REF 'r' +#define BLOCK_TYPE_OBJ 'o' +#define BLOCK_TYPE_ANY 0 + +#define MAX_RESTARTS ((1 << 16) - 1) +#define DEFAULT_BLOCK_SIZE 4096 + +#endif diff --git a/reftable/dump.c b/reftable/dump.c new file mode 100644 index 0000000000..acabe18fbe --- /dev/null +++ b/reftable/dump.c @@ -0,0 +1,97 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#include "system.h" + +#include "reftable.h" + +static int dump_table(const char *tablename) +{ + struct block_source src = {}; + int err = block_source_from_file(&src, tablename); + if (err < 0) { + return err; + } + + struct reader *r = NULL; + err = new_reader(&r, src, tablename); + if (err < 0) { + return err; + } + + { + struct iterator it = {}; + err = reader_seek_ref(r, &it, ""); + if (err < 0) { + return err; + } + + struct ref_record ref = {}; + while (1) { + err = iterator_next_ref(it, &ref); + if (err > 0) { + break; + } + if (err < 0) { + return err; + } + ref_record_print(&ref, 20); + } + iterator_destroy(&it); + ref_record_clear(&ref); + } + + { + struct iterator it = {}; + err = reader_seek_log(r, &it, ""); + if (err < 0) { + return err; + } + struct log_record log = {}; + while (1) { + err = iterator_next_log(it, &log); + if (err > 0) { + break; + } + if (err < 0) { + return err; + } + log_record_print(&log, 20); + } + iterator_destroy(&it); + log_record_clear(&log); + } + return 0; +} + +int main(int argc, char *argv[]) +{ + int opt; + const char *table = NULL; + while ((opt = getopt(argc, argv, "t:")) != -1) { + switch (opt) { + case 't': + table = strdup(optarg); + break; + case '?': + printf("usage: %s [-table tablefile]\n", argv[0]); + return 2; + break; + } + } + + if (table != NULL) { + int err = dump_table(table); + if (err < 0) { + fprintf(stderr, "%s: %s: %s\n", argv[0], table, + error_str(err)); + return 1; + } + } + return 0; +} diff --git a/reftable/file.c b/reftable/file.c new file mode 100644 index 0000000000..b2ea90bf94 --- /dev/null +++ b/reftable/file.c @@ -0,0 +1,97 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#include "system.h" + +#include "block.h" +#include "iter.h" +#include "record.h" +#include "reftable.h" +#include "tree.h" + +struct file_block_source { + int fd; + uint64_t size; +}; + +static uint64_t file_size(void *b) +{ + return ((struct file_block_source *)b)->size; +} + +static void file_return_block(void *b, struct block *dest) +{ + memset(dest->data, 0xff, dest->len); + free(dest->data); +} + +static void file_close(void *b) +{ + int fd = ((struct file_block_source *)b)->fd; + if (fd > 0) { + close(fd); + ((struct file_block_source *)b)->fd = 0; + } + + free(b); +} + +static int file_read_block(void *v, struct block *dest, uint64_t off, + uint32_t size) +{ + struct file_block_source *b = (struct file_block_source *)v; + assert(off + size <= b->size); + dest->data = malloc(size); + if (pread(b->fd, dest->data, size, off) != size) { + return -1; + } + dest->len = size; + return size; +} + +struct block_source_vtable file_vtable = { + .size = &file_size, + .read_block = &file_read_block, + .return_block = &file_return_block, + .close = &file_close, +}; + +int block_source_from_file(struct block_source *bs, const char *name) +{ + struct stat st = {}; + int err = 0; + int fd = open(name, O_RDONLY); + if (fd < 0) { + if (errno == ENOENT) { + return NOT_EXIST_ERROR; + } + return -1; + } + + err = fstat(fd, &st); + if (err < 0) { + return -1; + } + + { + struct file_block_source *p = + calloc(sizeof(struct file_block_source), 1); + p->size = st.st_size; + p->fd = fd; + + bs->ops = &file_vtable; + bs->arg = p; + } + return 0; +} + +int fd_writer(void *arg, byte *data, int sz) +{ + int *fdp = (int *)arg; + return write(*fdp, data, sz); +} diff --git a/reftable/iter.c b/reftable/iter.c new file mode 100644 index 0000000000..c06c891366 --- /dev/null +++ b/reftable/iter.c @@ -0,0 +1,229 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#include "iter.h" + +#include "system.h" + +#include "block.h" +#include "constants.h" +#include "reader.h" +#include "reftable.h" + +bool iterator_is_null(struct iterator it) +{ + return it.ops == NULL; +} + +static int empty_iterator_next(void *arg, struct record rec) +{ + return 1; +} + +static void empty_iterator_close(void *arg) +{ +} + +struct iterator_vtable empty_vtable = { + .next = &empty_iterator_next, + .close = &empty_iterator_close, +}; + +void iterator_set_empty(struct iterator *it) +{ + it->iter_arg = NULL; + it->ops = &empty_vtable; +} + +int iterator_next(struct iterator it, struct record rec) +{ + return it.ops->next(it.iter_arg, rec); +} + +void iterator_destroy(struct iterator *it) +{ + if (it->ops == NULL) { + return; + } + it->ops->close(it->iter_arg); + it->ops = NULL; + FREE_AND_NULL(it->iter_arg); +} + +int iterator_next_ref(struct iterator it, struct ref_record *ref) +{ + struct record rec = {}; + record_from_ref(&rec, ref); + return iterator_next(it, rec); +} + +int iterator_next_log(struct iterator it, struct log_record *log) +{ + struct record rec = {}; + record_from_log(&rec, log); + return iterator_next(it, rec); +} + +static void filtering_ref_iterator_close(void *iter_arg) +{ + struct filtering_ref_iterator *fri = + (struct filtering_ref_iterator *)iter_arg; + free(slice_yield(&fri->oid)); + iterator_destroy(&fri->it); +} + +static int filtering_ref_iterator_next(void *iter_arg, struct record rec) +{ + struct filtering_ref_iterator *fri = + (struct filtering_ref_iterator *)iter_arg; + struct ref_record *ref = (struct ref_record *)rec.data; + + while (true) { + int err = iterator_next_ref(fri->it, ref); + if (err != 0) { + return err; + } + + if (fri->double_check) { + struct iterator it = {}; + + int err = reader_seek_ref(fri->r, &it, ref->ref_name); + if (err == 0) { + err = iterator_next_ref(it, ref); + } + + iterator_destroy(&it); + + if (err < 0) { + return err; + } + + if (err > 0) { + continue; + } + } + + if ((ref->target_value != NULL && + !memcmp(fri->oid.buf, ref->target_value, fri->oid.len)) || + (ref->value != NULL && + !memcmp(fri->oid.buf, ref->value, fri->oid.len))) { + return 0; + } + } +} + +struct iterator_vtable filtering_ref_iterator_vtable = { + .next = &filtering_ref_iterator_next, + .close = &filtering_ref_iterator_close, +}; + +void iterator_from_filtering_ref_iterator(struct iterator *it, + struct filtering_ref_iterator *fri) +{ + it->iter_arg = fri; + it->ops = &filtering_ref_iterator_vtable; +} + +static void indexed_table_ref_iter_close(void *p) +{ + struct indexed_table_ref_iter *it = (struct indexed_table_ref_iter *)p; + block_iter_close(&it->cur); + reader_return_block(it->r, &it->block_reader.block); + free(slice_yield(&it->oid)); +} + +static int indexed_table_ref_iter_next_block(struct indexed_table_ref_iter *it) +{ + if (it->offset_idx == it->offset_len) { + it->finished = true; + return 1; + } + + reader_return_block(it->r, &it->block_reader.block); + + { + uint64_t off = it->offsets[it->offset_idx++]; + int err = reader_init_block_reader(it->r, &it->block_reader, + off, BLOCK_TYPE_REF); + if (err < 0) { + return err; + } + if (err > 0) { + /* indexed block does not exist. */ + return FORMAT_ERROR; + } + } + block_reader_start(&it->block_reader, &it->cur); + return 0; +} + +static int indexed_table_ref_iter_next(void *p, struct record rec) +{ + struct indexed_table_ref_iter *it = (struct indexed_table_ref_iter *)p; + struct ref_record *ref = (struct ref_record *)rec.data; + + while (true) { + int err = block_iter_next(&it->cur, rec); + if (err < 0) { + return err; + } + + if (err > 0) { + err = indexed_table_ref_iter_next_block(it); + if (err < 0) { + return err; + } + + if (it->finished) { + return 1; + } + continue; + } + + if (!memcmp(it->oid.buf, ref->target_value, it->oid.len) || + !memcmp(it->oid.buf, ref->value, it->oid.len)) { + return 0; + } + } +} + +int new_indexed_table_ref_iter(struct indexed_table_ref_iter **dest, + struct reader *r, byte *oid, int oid_len, + uint64_t *offsets, int offset_len) +{ + struct indexed_table_ref_iter *itr = + calloc(sizeof(struct indexed_table_ref_iter), 1); + int err = 0; + + itr->r = r; + slice_resize(&itr->oid, oid_len); + memcpy(itr->oid.buf, oid, oid_len); + + itr->offsets = offsets; + itr->offset_len = offset_len; + + err = indexed_table_ref_iter_next_block(itr); + if (err < 0) { + free(itr); + } else { + *dest = itr; + } + return err; +} + +struct iterator_vtable indexed_table_ref_iter_vtable = { + .next = &indexed_table_ref_iter_next, + .close = &indexed_table_ref_iter_close, +}; + +void iterator_from_indexed_table_ref_iter(struct iterator *it, + struct indexed_table_ref_iter *itr) +{ + it->iter_arg = itr; + it->ops = &indexed_table_ref_iter_vtable; +} diff --git a/reftable/iter.h b/reftable/iter.h new file mode 100644 index 0000000000..f497f2a27e --- /dev/null +++ b/reftable/iter.h @@ -0,0 +1,56 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef ITER_H +#define ITER_H + +#include "block.h" +#include "record.h" +#include "slice.h" + +struct iterator_vtable { + int (*next)(void *iter_arg, struct record rec); + void (*close)(void *iter_arg); +}; + +void iterator_set_empty(struct iterator *it); +int iterator_next(struct iterator it, struct record rec); +bool iterator_is_null(struct iterator it); + +struct filtering_ref_iterator { + struct reader *r; + struct slice oid; + bool double_check; + struct iterator it; +}; + +void iterator_from_filtering_ref_iterator(struct iterator *, + struct filtering_ref_iterator *); + +struct indexed_table_ref_iter { + struct reader *r; + struct slice oid; + + /* mutable */ + uint64_t *offsets; + + /* Points to the next offset to read. */ + int offset_idx; + int offset_len; + struct block_reader block_reader; + struct block_iter cur; + bool finished; +}; + +void iterator_from_indexed_table_ref_iter(struct iterator *it, + struct indexed_table_ref_iter *itr); +int new_indexed_table_ref_iter(struct indexed_table_ref_iter **dest, + struct reader *r, byte *oid, int oid_len, + uint64_t *offsets, int offset_len); + +#endif diff --git a/reftable/merged.c b/reftable/merged.c new file mode 100644 index 0000000000..7d52ec6232 --- /dev/null +++ b/reftable/merged.c @@ -0,0 +1,286 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#include "merged.h" + +#include "system.h" + +#include "constants.h" +#include "iter.h" +#include "pq.h" +#include "reader.h" + +static int merged_iter_init(struct merged_iter *mi) +{ + int i = 0; + for (i = 0; i < mi->stack_len; i++) { + struct record rec = new_record(mi->typ); + int err = iterator_next(mi->stack[i], rec); + if (err < 0) { + return err; + } + + if (err > 0) { + iterator_destroy(&mi->stack[i]); + record_clear(rec); + free(record_yield(&rec)); + } else { + struct pq_entry e = { + .rec = rec, + .index = i, + }; + merged_iter_pqueue_add(&mi->pq, e); + } + } + + return 0; +} + +static void merged_iter_close(void *p) +{ + struct merged_iter *mi = (struct merged_iter *)p; + int i = 0; + merged_iter_pqueue_clear(&mi->pq); + for (i = 0; i < mi->stack_len; i++) { + iterator_destroy(&mi->stack[i]); + } + free(mi->stack); +} + +static int merged_iter_advance_subiter(struct merged_iter *mi, int idx) +{ + if (iterator_is_null(mi->stack[idx])) { + return 0; + } + + { + struct record rec = new_record(mi->typ); + struct pq_entry e = { + .rec = rec, + .index = idx, + }; + int err = iterator_next(mi->stack[idx], rec); + if (err < 0) { + return err; + } + + if (err > 0) { + iterator_destroy(&mi->stack[idx]); + record_clear(rec); + free(record_yield(&rec)); + return 0; + } + + merged_iter_pqueue_add(&mi->pq, e); + } + return 0; +} + +static int merged_iter_next(struct merged_iter *mi, struct record rec) +{ + struct slice entry_key = {}; + struct pq_entry entry = merged_iter_pqueue_remove(&mi->pq); + int err = merged_iter_advance_subiter(mi, entry.index); + if (err < 0) { + return err; + } + + record_key(entry.rec, &entry_key); + while (!merged_iter_pqueue_is_empty(mi->pq)) { + struct pq_entry top = merged_iter_pqueue_top(mi->pq); + struct slice k = {}; + int err = 0, cmp = 0; + + record_key(top.rec, &k); + + cmp = slice_compare(k, entry_key); + free(slice_yield(&k)); + + if (cmp > 0) { + break; + } + + merged_iter_pqueue_remove(&mi->pq); + err = merged_iter_advance_subiter(mi, top.index); + if (err < 0) { + return err; + } + record_clear(top.rec); + free(record_yield(&top.rec)); + } + + record_copy_from(rec, entry.rec, mi->hash_size); + record_clear(entry.rec); + free(record_yield(&entry.rec)); + free(slice_yield(&entry_key)); + return 0; +} + +static int merged_iter_next_void(void *p, struct record rec) +{ + struct merged_iter *mi = (struct merged_iter *)p; + if (merged_iter_pqueue_is_empty(mi->pq)) { + return 1; + } + + return merged_iter_next(mi, rec); +} + +struct iterator_vtable merged_iter_vtable = { + .next = &merged_iter_next_void, + .close = &merged_iter_close, +}; + +static void iterator_from_merged_iter(struct iterator *it, + struct merged_iter *mi) +{ + it->iter_arg = mi; + it->ops = &merged_iter_vtable; +} + +int new_merged_table(struct merged_table **dest, struct reader **stack, int n) +{ + uint64_t last_max = 0; + uint64_t first_min = 0; + int i = 0; + for (i = 0; i < n; i++) { + struct reader *r = stack[i]; + if (i > 0 && last_max >= reader_min_update_index(r)) { + return FORMAT_ERROR; + } + if (i == 0) { + first_min = reader_min_update_index(r); + } + + last_max = reader_max_update_index(r); + } + + { + struct merged_table m = { + .stack = stack, + .stack_len = n, + .min = first_min, + .max = last_max, + .hash_size = SHA1_SIZE, + }; + + *dest = calloc(sizeof(struct merged_table), 1); + **dest = m; + } + return 0; +} + +void merged_table_close(struct merged_table *mt) +{ + int i = 0; + for (i = 0; i < mt->stack_len; i++) { + reader_free(mt->stack[i]); + } + FREE_AND_NULL(mt->stack); + mt->stack_len = 0; +} + +/* clears the list of subtable, without affecting the readers themselves. */ +void merged_table_clear(struct merged_table *mt) +{ + FREE_AND_NULL(mt->stack); + mt->stack_len = 0; +} + +void merged_table_free(struct merged_table *mt) +{ + if (mt == NULL) { + return; + } + merged_table_clear(mt); + free(mt); +} + +uint64_t merged_max_update_index(struct merged_table *mt) +{ + return mt->max; +} + +uint64_t merged_min_update_index(struct merged_table *mt) +{ + return mt->min; +} + +static int merged_table_seek_record(struct merged_table *mt, + struct iterator *it, struct record rec) +{ + struct iterator *iters = calloc(sizeof(struct iterator), mt->stack_len); + struct merged_iter merged = { + .stack = iters, + .typ = record_type(rec), + .hash_size = mt->hash_size, + }; + int n = 0; + int err = 0; + int i = 0; + for (i = 0; i < mt->stack_len && err == 0; i++) { + int e = reader_seek(mt->stack[i], &iters[n], rec); + if (e < 0) { + err = e; + } + if (e == 0) { + n++; + } + } + if (err < 0) { + int i = 0; + for (i = 0; i < n; i++) { + iterator_destroy(&iters[i]); + } + free(iters); + return err; + } + + merged.stack_len = n, err = merged_iter_init(&merged); + if (err < 0) { + merged_iter_close(&merged); + return err; + } + + { + struct merged_iter *p = malloc(sizeof(struct merged_iter)); + *p = merged; + iterator_from_merged_iter(it, p); + } + return 0; +} + +int merged_table_seek_ref(struct merged_table *mt, struct iterator *it, + const char *name) +{ + struct ref_record ref = { + .ref_name = (char *)name, + }; + struct record rec = {}; + record_from_ref(&rec, &ref); + return merged_table_seek_record(mt, it, rec); +} + +int merged_table_seek_log_at(struct merged_table *mt, struct iterator *it, + const char *name, uint64_t update_index) +{ + struct log_record log = { + .ref_name = (char *)name, + .update_index = update_index, + }; + struct record rec = {}; + record_from_log(&rec, &log); + return merged_table_seek_record(mt, it, rec); +} + +int merged_table_seek_log(struct merged_table *mt, struct iterator *it, + const char *name) +{ + uint64_t max = ~((uint64_t)0); + return merged_table_seek_log_at(mt, it, name, max); +} diff --git a/reftable/merged.h b/reftable/merged.h new file mode 100644 index 0000000000..b8d3572e26 --- /dev/null +++ b/reftable/merged.h @@ -0,0 +1,34 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef MERGED_H +#define MERGED_H + +#include "pq.h" +#include "reftable.h" + +struct merged_table { + struct reader **stack; + int stack_len; + int hash_size; + + uint64_t min; + uint64_t max; +}; + +struct merged_iter { + struct iterator *stack; + int hash_size; + int stack_len; + byte typ; + struct merged_iter_pqueue pq; +} merged_iter; + +void merged_table_clear(struct merged_table *mt); + +#endif diff --git a/reftable/pq.c b/reftable/pq.c new file mode 100644 index 0000000000..a1aff7c98c --- /dev/null +++ b/reftable/pq.c @@ -0,0 +1,114 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#include "pq.h" + +#include "system.h" + +int pq_less(struct pq_entry a, struct pq_entry b) +{ + struct slice ak = {}; + struct slice bk = {}; + int cmp = 0; + record_key(a.rec, &ak); + record_key(b.rec, &bk); + + cmp = slice_compare(ak, bk); + + free(slice_yield(&ak)); + free(slice_yield(&bk)); + + if (cmp == 0) { + return a.index > b.index; + } + + return cmp < 0; +} + +struct pq_entry merged_iter_pqueue_top(struct merged_iter_pqueue pq) +{ + return pq.heap[0]; +} + +bool merged_iter_pqueue_is_empty(struct merged_iter_pqueue pq) +{ + return pq.len == 0; +} + +void merged_iter_pqueue_check(struct merged_iter_pqueue pq) +{ + int i = 0; + for (i = 1; i < pq.len; i++) { + int parent = (i - 1) / 2; + + assert(pq_less(pq.heap[parent], pq.heap[i])); + } +} + +struct pq_entry merged_iter_pqueue_remove(struct merged_iter_pqueue *pq) +{ + int i = 0; + struct pq_entry e = pq->heap[0]; + pq->heap[0] = pq->heap[pq->len - 1]; + pq->len--; + + i = 0; + while (i < pq->len) { + int min = i; + int j = 2 * i + 1; + int k = 2 * i + 2; + if (j < pq->len && pq_less(pq->heap[j], pq->heap[i])) { + min = j; + } + if (k < pq->len && pq_less(pq->heap[k], pq->heap[min])) { + min = k; + } + + if (min == i) { + break; + } + + SWAP(pq->heap[i], pq->heap[min]); + i = min; + } + + return e; +} + +void merged_iter_pqueue_add(struct merged_iter_pqueue *pq, struct pq_entry e) +{ + int i = 0; + if (pq->len == pq->cap) { + pq->cap = 2 * pq->cap + 1; + pq->heap = realloc(pq->heap, pq->cap * sizeof(struct pq_entry)); + } + + pq->heap[pq->len++] = e; + i = pq->len - 1; + while (i > 0) { + int j = (i - 1) / 2; + if (pq_less(pq->heap[j], pq->heap[i])) { + break; + } + + SWAP(pq->heap[j], pq->heap[i]); + + i = j; + } +} + +void merged_iter_pqueue_clear(struct merged_iter_pqueue *pq) +{ + int i = 0; + for (i = 0; i < pq->len; i++) { + record_clear(pq->heap[i].rec); + free(record_yield(&pq->heap[i].rec)); + } + FREE_AND_NULL(pq->heap); + pq->len = pq->cap = 0; +} diff --git a/reftable/pq.h b/reftable/pq.h new file mode 100644 index 0000000000..5f7018979d --- /dev/null +++ b/reftable/pq.h @@ -0,0 +1,34 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef PQ_H +#define PQ_H + +#include "record.h" + +struct pq_entry { + struct record rec; + int index; +}; + +int pq_less(struct pq_entry a, struct pq_entry b); + +struct merged_iter_pqueue { + struct pq_entry *heap; + int len; + int cap; +}; + +struct pq_entry merged_iter_pqueue_top(struct merged_iter_pqueue pq); +bool merged_iter_pqueue_is_empty(struct merged_iter_pqueue pq); +void merged_iter_pqueue_check(struct merged_iter_pqueue pq); +struct pq_entry merged_iter_pqueue_remove(struct merged_iter_pqueue *pq); +void merged_iter_pqueue_add(struct merged_iter_pqueue *pq, struct pq_entry e); +void merged_iter_pqueue_clear(struct merged_iter_pqueue *pq); + +#endif diff --git a/reftable/reader.c b/reftable/reader.c new file mode 100644 index 0000000000..981911f076 --- /dev/null +++ b/reftable/reader.c @@ -0,0 +1,708 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#include "reader.h" + +#include "system.h" + +#include "block.h" +#include "constants.h" +#include "iter.h" +#include "record.h" +#include "reftable.h" +#include "tree.h" + +uint64_t block_source_size(struct block_source source) +{ + return source.ops->size(source.arg); +} + +int block_source_read_block(struct block_source source, struct block *dest, + uint64_t off, uint32_t size) +{ + int result = source.ops->read_block(source.arg, dest, off, size); + dest->source = source; + return result; +} + +void block_source_return_block(struct block_source source, struct block *blockp) +{ + source.ops->return_block(source.arg, blockp); + blockp->data = NULL; + blockp->len = 0; + blockp->source.ops = NULL; + blockp->source.arg = NULL; +} + +void block_source_close(struct block_source *source) +{ + if (source->ops == NULL) { + return; + } + + source->ops->close(source->arg); + source->ops = NULL; +} + +static struct reader_offsets *reader_offsets_for(struct reader *r, byte typ) +{ + switch (typ) { + case BLOCK_TYPE_REF: + return &r->ref_offsets; + case BLOCK_TYPE_LOG: + return &r->log_offsets; + case BLOCK_TYPE_OBJ: + return &r->obj_offsets; + } + abort(); +} + +static int reader_get_block(struct reader *r, struct block *dest, uint64_t off, + uint32_t sz) +{ + if (off >= r->size) { + return 0; + } + + if (off + sz > r->size) { + sz = r->size - off; + } + + return block_source_read_block(r->source, dest, off, sz); +} + +void reader_return_block(struct reader *r, struct block *p) +{ + block_source_return_block(r->source, p); +} + +const char *reader_name(struct reader *r) +{ + return r->name; +} + +static int parse_footer(struct reader *r, byte *footer, byte *header) +{ + byte *f = footer; + int err = 0; + if (memcmp(f, "REFT", 4)) { + err = FORMAT_ERROR; + goto exit; + } + f += 4; + + if (memcmp(footer, header, HEADER_SIZE)) { + err = FORMAT_ERROR; + goto exit; + } + + { + byte version = *f++; + if (version != 1) { + err = FORMAT_ERROR; + goto exit; + } + } + + r->block_size = get_u24(f); + + f += 3; + r->min_update_index = get_u64(f); + f += 8; + r->max_update_index = get_u64(f); + f += 8; + + r->ref_offsets.index_offset = get_u64(f); + f += 8; + + r->obj_offsets.offset = get_u64(f); + f += 8; + + r->object_id_len = r->obj_offsets.offset & ((1 << 5) - 1); + r->obj_offsets.offset >>= 5; + + r->obj_offsets.index_offset = get_u64(f); + f += 8; + r->log_offsets.offset = get_u64(f); + f += 8; + r->log_offsets.index_offset = get_u64(f); + f += 8; + + { + uint32_t computed_crc = crc32(0, footer, f - footer); + uint32_t file_crc = get_u32(f); + f += 4; + if (computed_crc != file_crc) { + err = FORMAT_ERROR; + goto exit; + } + } + + { + byte first_block_typ = header[HEADER_SIZE]; + r->ref_offsets.present = (first_block_typ == BLOCK_TYPE_REF); + r->ref_offsets.offset = 0; + r->log_offsets.present = (first_block_typ == BLOCK_TYPE_LOG || + r->log_offsets.offset > 0); + r->obj_offsets.present = r->obj_offsets.offset > 0; + } + err = 0; +exit: + return err; +} + +int init_reader(struct reader *r, struct block_source source, const char *name) +{ + struct block footer = {}; + struct block header = {}; + int err = 0; + + memset(r, 0, sizeof(struct reader)); + r->size = block_source_size(source) - FOOTER_SIZE; + r->source = source; + r->name = strdup(name); + r->hash_size = SHA1_SIZE; + + err = block_source_read_block(source, &footer, r->size, FOOTER_SIZE); + if (err != FOOTER_SIZE) { + err = IO_ERROR; + goto exit; + } + + /* Need +1 to read type of first block. */ + err = reader_get_block(r, &header, 0, HEADER_SIZE + 1); + if (err != HEADER_SIZE + 1) { + err = IO_ERROR; + goto exit; + } + + err = parse_footer(r, footer.data, header.data); +exit: + block_source_return_block(r->source, &footer); + block_source_return_block(r->source, &header); + return err; +} + +struct table_iter { + struct reader *r; + byte typ; + uint64_t block_off; + struct block_iter bi; + bool finished; +}; + +static void table_iter_copy_from(struct table_iter *dest, + struct table_iter *src) +{ + dest->r = src->r; + dest->typ = src->typ; + dest->block_off = src->block_off; + dest->finished = src->finished; + block_iter_copy_from(&dest->bi, &src->bi); +} + +static int table_iter_next_in_block(struct table_iter *ti, struct record rec) +{ + int res = block_iter_next(&ti->bi, rec); + if (res == 0 && record_type(rec) == BLOCK_TYPE_REF) { + ((struct ref_record *)rec.data)->update_index += + ti->r->min_update_index; + } + + return res; +} + +static void table_iter_block_done(struct table_iter *ti) +{ + if (ti->bi.br == NULL) { + return; + } + reader_return_block(ti->r, &ti->bi.br->block); + FREE_AND_NULL(ti->bi.br); + + ti->bi.last_key.len = 0; + ti->bi.next_off = 0; +} + +static int32_t extract_block_size(byte *data, byte *typ, uint64_t off) +{ + int32_t result = 0; + + if (off == 0) { + data += 24; + } + + *typ = data[0]; + if (is_block_type(*typ)) { + result = get_u24(data + 1); + } + return result; +} + +int reader_init_block_reader(struct reader *r, struct block_reader *br, + uint64_t next_off, byte want_typ) +{ + int32_t guess_block_size = r->block_size ? r->block_size : + DEFAULT_BLOCK_SIZE; + struct block block = {}; + byte block_typ = 0; + int err = 0; + uint32_t header_off = next_off ? 0 : HEADER_SIZE; + int32_t block_size = 0; + + if (next_off >= r->size) { + return 1; + } + + err = reader_get_block(r, &block, next_off, guess_block_size); + if (err < 0) { + return err; + } + + block_size = extract_block_size(block.data, &block_typ, next_off); + if (block_size < 0) { + return block_size; + } + + if (want_typ != BLOCK_TYPE_ANY && block_typ != want_typ) { + reader_return_block(r, &block); + return 1; + } + + if (block_size > guess_block_size) { + reader_return_block(r, &block); + err = reader_get_block(r, &block, next_off, block_size); + if (err < 0) { + return err; + } + } + + return block_reader_init(br, &block, header_off, r->block_size, + r->hash_size); +} + +static int table_iter_next_block(struct table_iter *dest, + struct table_iter *src) +{ + uint64_t next_block_off = src->block_off + src->bi.br->full_block_size; + struct block_reader br = {}; + int err = 0; + + dest->r = src->r; + dest->typ = src->typ; + dest->block_off = next_block_off; + + err = reader_init_block_reader(src->r, &br, next_block_off, src->typ); + if (err > 0) { + dest->finished = true; + return 1; + } + if (err != 0) { + return err; + } + + { + struct block_reader *brp = malloc(sizeof(struct block_reader)); + *brp = br; + + dest->finished = false; + block_reader_start(brp, &dest->bi); + } + return 0; +} + +static int table_iter_next(struct table_iter *ti, struct record rec) +{ + if (record_type(rec) != ti->typ) { + return API_ERROR; + } + + while (true) { + struct table_iter next = {}; + int err = 0; + if (ti->finished) { + return 1; + } + + err = table_iter_next_in_block(ti, rec); + if (err <= 0) { + return err; + } + + err = table_iter_next_block(&next, ti); + if (err != 0) { + ti->finished = true; + } + table_iter_block_done(ti); + if (err != 0) { + return err; + } + table_iter_copy_from(ti, &next); + block_iter_close(&next.bi); + } +} + +static int table_iter_next_void(void *ti, struct record rec) +{ + return table_iter_next((struct table_iter *)ti, rec); +} + +static void table_iter_close(void *p) +{ + struct table_iter *ti = (struct table_iter *)p; + table_iter_block_done(ti); + block_iter_close(&ti->bi); +} + +struct iterator_vtable table_iter_vtable = { + .next = &table_iter_next_void, + .close = &table_iter_close, +}; + +static void iterator_from_table_iter(struct iterator *it, struct table_iter *ti) +{ + it->iter_arg = ti; + it->ops = &table_iter_vtable; +} + +static int reader_table_iter_at(struct reader *r, struct table_iter *ti, + uint64_t off, byte typ) +{ + struct block_reader br = {}; + struct block_reader *brp = NULL; + + int err = reader_init_block_reader(r, &br, off, typ); + if (err != 0) { + return err; + } + + brp = malloc(sizeof(struct block_reader)); + *brp = br; + ti->r = r; + ti->typ = block_reader_type(brp); + ti->block_off = off; + block_reader_start(brp, &ti->bi); + return 0; +} + +static int reader_start(struct reader *r, struct table_iter *ti, byte typ, + bool index) +{ + struct reader_offsets *offs = reader_offsets_for(r, typ); + uint64_t off = offs->offset; + if (index) { + off = offs->index_offset; + if (off == 0) { + return 1; + } + typ = BLOCK_TYPE_INDEX; + } + + return reader_table_iter_at(r, ti, off, typ); +} + +static int reader_seek_linear(struct reader *r, struct table_iter *ti, + struct record want) +{ + struct record rec = new_record(record_type(want)); + struct slice want_key = {}; + struct slice got_key = {}; + struct table_iter next = {}; + int err = -1; + record_key(want, &want_key); + + while (true) { + err = table_iter_next_block(&next, ti); + if (err < 0) { + goto exit; + } + + if (err > 0) { + break; + } + + err = block_reader_first_key(next.bi.br, &got_key); + if (err < 0) { + goto exit; + } + { + int cmp = slice_compare(got_key, want_key); + if (cmp > 0) { + table_iter_block_done(&next); + break; + } + } + + table_iter_block_done(ti); + table_iter_copy_from(ti, &next); + } + + err = block_iter_seek(&ti->bi, want_key); + if (err < 0) { + goto exit; + } + err = 0; + +exit: + block_iter_close(&next.bi); + record_clear(rec); + free(record_yield(&rec)); + free(slice_yield(&want_key)); + free(slice_yield(&got_key)); + return err; +} + +static int reader_seek_indexed(struct reader *r, struct iterator *it, + struct record rec) +{ + struct index_record want_index = {}; + struct record want_index_rec = {}; + struct index_record index_result = {}; + struct record index_result_rec = {}; + struct table_iter index_iter = {}; + struct table_iter next = {}; + int err = 0; + + record_key(rec, &want_index.last_key); + record_from_index(&want_index_rec, &want_index); + record_from_index(&index_result_rec, &index_result); + + err = reader_start(r, &index_iter, record_type(rec), true); + if (err < 0) { + goto exit; + } + + err = reader_seek_linear(r, &index_iter, want_index_rec); + while (true) { + err = table_iter_next(&index_iter, index_result_rec); + table_iter_block_done(&index_iter); + if (err != 0) { + goto exit; + } + + err = reader_table_iter_at(r, &next, index_result.offset, 0); + if (err != 0) { + goto exit; + } + + err = block_iter_seek(&next.bi, want_index.last_key); + if (err < 0) { + goto exit; + } + + if (next.typ == record_type(rec)) { + err = 0; + break; + } + + if (next.typ != BLOCK_TYPE_INDEX) { + err = FORMAT_ERROR; + break; + } + + table_iter_copy_from(&index_iter, &next); + } + + if (err == 0) { + struct table_iter *malloced = + calloc(sizeof(struct table_iter), 1); + table_iter_copy_from(malloced, &next); + iterator_from_table_iter(it, malloced); + } +exit: + block_iter_close(&next.bi); + table_iter_close(&index_iter); + record_clear(want_index_rec); + record_clear(index_result_rec); + return err; +} + +static int reader_seek_internal(struct reader *r, struct iterator *it, + struct record rec) +{ + struct reader_offsets *offs = reader_offsets_for(r, record_type(rec)); + uint64_t idx = offs->index_offset; + struct table_iter ti = {}; + int err = 0; + if (idx > 0) { + return reader_seek_indexed(r, it, rec); + } + + err = reader_start(r, &ti, record_type(rec), false); + if (err < 0) { + return err; + } + err = reader_seek_linear(r, &ti, rec); + if (err < 0) { + return err; + } + + { + struct table_iter *p = malloc(sizeof(struct table_iter)); + *p = ti; + iterator_from_table_iter(it, p); + } + + return 0; +} + +int reader_seek(struct reader *r, struct iterator *it, struct record rec) +{ + byte typ = record_type(rec); + + struct reader_offsets *offs = reader_offsets_for(r, typ); + if (!offs->present) { + iterator_set_empty(it); + return 0; + } + + return reader_seek_internal(r, it, rec); +} + +int reader_seek_ref(struct reader *r, struct iterator *it, const char *name) +{ + struct ref_record ref = { + .ref_name = (char *)name, + }; + struct record rec = {}; + record_from_ref(&rec, &ref); + return reader_seek(r, it, rec); +} + +int reader_seek_log_at(struct reader *r, struct iterator *it, const char *name, + uint64_t update_index) +{ + struct log_record log = { + .ref_name = (char *)name, + .update_index = update_index, + }; + struct record rec = {}; + record_from_log(&rec, &log); + return reader_seek(r, it, rec); +} + +int reader_seek_log(struct reader *r, struct iterator *it, const char *name) +{ + uint64_t max = ~((uint64_t)0); + return reader_seek_log_at(r, it, name, max); +} + +void reader_close(struct reader *r) +{ + block_source_close(&r->source); + FREE_AND_NULL(r->name); +} + +int new_reader(struct reader **p, struct block_source src, char const *name) +{ + struct reader *rd = calloc(sizeof(struct reader), 1); + int err = init_reader(rd, src, name); + if (err == 0) { + *p = rd; + } else { + free(rd); + } + return err; +} + +void reader_free(struct reader *r) +{ + reader_close(r); + free(r); +} + +static int reader_refs_for_indexed(struct reader *r, struct iterator *it, + byte *oid) +{ + struct obj_record want = { + .hash_prefix = oid, + .hash_prefix_len = r->object_id_len, + }; + struct record want_rec = {}; + struct iterator oit = {}; + struct obj_record got = {}; + struct record got_rec = {}; + int err = 0; + + record_from_obj(&want_rec, &want); + + err = reader_seek(r, &oit, want_rec); + if (err != 0) { + return err; + } + + record_from_obj(&got_rec, &got); + err = iterator_next(oit, got_rec); + iterator_destroy(&oit); + if (err < 0) { + return err; + } + + if (err > 0 || + memcmp(want.hash_prefix, got.hash_prefix, r->object_id_len)) { + iterator_set_empty(it); + return 0; + } + + { + struct indexed_table_ref_iter *itr = NULL; + err = new_indexed_table_ref_iter(&itr, r, oid, r->hash_size, + got.offsets, got.offset_len); + if (err < 0) { + record_clear(got_rec); + return err; + } + got.offsets = NULL; + record_clear(got_rec); + + iterator_from_indexed_table_ref_iter(it, itr); + } + + return 0; +} + +static int reader_refs_for_unindexed(struct reader *r, struct iterator *it, + byte *oid, int oid_len) +{ + struct table_iter *ti = calloc(sizeof(struct table_iter), 1); + struct filtering_ref_iterator *filter = NULL; + int err = reader_start(r, ti, BLOCK_TYPE_REF, false); + if (err < 0) { + free(ti); + return err; + } + + filter = calloc(sizeof(struct filtering_ref_iterator), 1); + slice_resize(&filter->oid, oid_len); + memcpy(filter->oid.buf, oid, oid_len); + filter->r = r; + filter->double_check = false; + iterator_from_table_iter(&filter->it, ti); + + iterator_from_filtering_ref_iterator(it, filter); + return 0; +} + +int reader_refs_for(struct reader *r, struct iterator *it, byte *oid, + int oid_len) +{ + if (r->obj_offsets.present) { + return reader_refs_for_indexed(r, it, oid); + } + return reader_refs_for_unindexed(r, it, oid, oid_len); +} + +uint64_t reader_max_update_index(struct reader *r) +{ + return r->max_update_index; +} + +uint64_t reader_min_update_index(struct reader *r) +{ + return r->min_update_index; +} diff --git a/reftable/reader.h b/reftable/reader.h new file mode 100644 index 0000000000..599a90028e --- /dev/null +++ b/reftable/reader.h @@ -0,0 +1,52 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef READER_H +#define READER_H + +#include "block.h" +#include "record.h" +#include "reftable.h" + +uint64_t block_source_size(struct block_source source); + +int block_source_read_block(struct block_source source, struct block *dest, + uint64_t off, uint32_t size); +void block_source_return_block(struct block_source source, struct block *ret); +void block_source_close(struct block_source *source); + +struct reader_offsets { + bool present; + uint64_t offset; + uint64_t index_offset; +}; + +struct reader { + struct block_source source; + char *name; + int hash_size; + uint64_t size; + uint32_t block_size; + uint64_t min_update_index; + uint64_t max_update_index; + int object_id_len; + + struct reader_offsets ref_offsets; + struct reader_offsets obj_offsets; + struct reader_offsets log_offsets; +}; + +int init_reader(struct reader *r, struct block_source source, const char *name); +int reader_seek(struct reader *r, struct iterator *it, struct record rec); +void reader_close(struct reader *r); +const char *reader_name(struct reader *r); +void reader_return_block(struct reader *r, struct block *p); +int reader_init_block_reader(struct reader *r, struct block_reader *br, + uint64_t next_off, byte want_typ); + +#endif diff --git a/reftable/record.c b/reftable/record.c new file mode 100644 index 0000000000..a006f9019d --- /dev/null +++ b/reftable/record.c @@ -0,0 +1,1107 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#include "record.h" + +#include "system.h" + +#include "constants.h" +#include "reftable.h" + +int is_block_type(byte typ) +{ + switch (typ) { + case BLOCK_TYPE_REF: + case BLOCK_TYPE_LOG: + case BLOCK_TYPE_OBJ: + case BLOCK_TYPE_INDEX: + return true; + } + return false; +} + +int get_var_int(uint64_t *dest, struct slice in) +{ + int ptr = 0; + uint64_t val; + + if (in.len == 0) { + return -1; + } + val = in.buf[ptr] & 0x7f; + + while (in.buf[ptr] & 0x80) { + ptr++; + if (ptr > in.len) { + return -1; + } + val = (val + 1) << 7 | (uint64_t)(in.buf[ptr] & 0x7f); + } + + *dest = val; + return ptr + 1; +} + +int put_var_int(struct slice dest, uint64_t val) +{ + byte buf[10] = {}; + int i = 9; + buf[i] = (byte)(val & 0x7f); + i--; + while (true) { + val >>= 7; + if (!val) { + break; + } + val--; + buf[i] = 0x80 | (byte)(val & 0x7f); + i--; + } + + { + int n = sizeof(buf) - i - 1; + if (dest.len < n) { + return -1; + } + memcpy(dest.buf, &buf[i + 1], n); + return n; + } +} + +int common_prefix_size(struct slice a, struct slice b) +{ + int p = 0; + while (p < a.len && p < b.len) { + if (a.buf[p] != b.buf[p]) { + break; + } + p++; + } + + return p; +} + +static int decode_string(struct slice *dest, struct slice in) +{ + int start_len = in.len; + uint64_t tsize = 0; + int n = get_var_int(&tsize, in); + if (n <= 0) { + return -1; + } + in.buf += n; + in.len -= n; + if (in.len < tsize) { + return -1; + } + + slice_resize(dest, tsize + 1); + dest->buf[tsize] = 0; + memcpy(dest->buf, in.buf, tsize); + in.buf += tsize; + in.len -= tsize; + + return start_len - in.len; +} + +int encode_key(bool *restart, struct slice dest, struct slice prev_key, + struct slice key, byte extra) +{ + struct slice start = dest; + int prefix_len = common_prefix_size(prev_key, key); + uint64_t suffix_len = key.len - prefix_len; + int n = put_var_int(dest, (uint64_t)prefix_len); + if (n < 0) { + return -1; + } + dest.buf += n; + dest.len -= n; + + *restart = (prefix_len == 0); + + n = put_var_int(dest, suffix_len << 3 | (uint64_t)extra); + if (n < 0) { + return -1; + } + dest.buf += n; + dest.len -= n; + + if (dest.len < suffix_len) { + return -1; + } + memcpy(dest.buf, key.buf + prefix_len, suffix_len); + dest.buf += suffix_len; + dest.len -= suffix_len; + + return start.len - dest.len; +} + +static byte ref_record_type(void) +{ + return BLOCK_TYPE_REF; +} + +static void ref_record_key(const void *r, struct slice *dest) +{ + const struct ref_record *rec = (const struct ref_record *)r; + slice_set_string(dest, rec->ref_name); +} + +static void ref_record_copy_from(void *rec, const void *src_rec, int hash_size) +{ + struct ref_record *ref = (struct ref_record *)rec; + struct ref_record *src = (struct ref_record *)src_rec; + assert(hash_size > 0); + + /* This is simple and correct, but we could probably reuse the hash + fields. */ + ref_record_clear(ref); + if (src->ref_name != NULL) { + ref->ref_name = strdup(src->ref_name); + } + + if (src->target != NULL) { + ref->target = strdup(src->target); + } + + if (src->target_value != NULL) { + ref->target_value = malloc(hash_size); + memcpy(ref->target_value, src->target_value, hash_size); + } + + if (src->value != NULL) { + ref->value = malloc(hash_size); + memcpy(ref->value, src->value, hash_size); + } + ref->update_index = src->update_index; +} + +static char hexdigit(int c) +{ + if (c <= 9) { + return '0' + c; + } + return 'a' + (c - 10); +} + +static void hex_format(char *dest, byte *src, int hash_size) +{ + assert(hash_size > 0); + if (src != NULL) { + int i = 0; + for (i = 0; i < hash_size; i++) { + dest[2 * i] = hexdigit(src[i] >> 4); + dest[2 * i + 1] = hexdigit(src[i] & 0xf); + } + dest[2 * hash_size] = 0; + } +} + +void ref_record_print(struct ref_record *ref, int hash_size) +{ + char hex[SHA256_SIZE + 1] = {}; + + printf("ref{%s(%" PRIu64 ") ", ref->ref_name, ref->update_index); + if (ref->value != NULL) { + hex_format(hex, ref->value, hash_size); + printf("%s", hex); + } + if (ref->target_value != NULL) { + hex_format(hex, ref->target_value, hash_size); + printf(" (T %s)", hex); + } + if (ref->target != NULL) { + printf("=> %s", ref->target); + } + printf("}\n"); +} + +static void ref_record_clear_void(void *rec) +{ + ref_record_clear((struct ref_record *)rec); +} + +void ref_record_clear(struct ref_record *ref) +{ + free(ref->ref_name); + free(ref->target); + free(ref->target_value); + free(ref->value); + memset(ref, 0, sizeof(struct ref_record)); +} + +static byte ref_record_val_type(const void *rec) +{ + const struct ref_record *r = (const struct ref_record *)rec; + if (r->value != NULL) { + if (r->target_value != NULL) { + return 2; + } else { + return 1; + } + } else if (r->target != NULL) { + return 3; + } + return 0; +} + +static int encode_string(char *str, struct slice s) +{ + struct slice start = s; + int l = strlen(str); + int n = put_var_int(s, l); + if (n < 0) { + return -1; + } + s.buf += n; + s.len -= n; + if (s.len < l) { + return -1; + } + memcpy(s.buf, str, l); + s.buf += l; + s.len -= l; + + return start.len - s.len; +} + +static int ref_record_encode(const void *rec, struct slice s, int hash_size) +{ + const struct ref_record *r = (const struct ref_record *)rec; + struct slice start = s; + int n = put_var_int(s, r->update_index); + assert(hash_size > 0); + if (n < 0) { + return -1; + } + s.buf += n; + s.len -= n; + + if (r->value != NULL) { + if (s.len < hash_size) { + return -1; + } + memcpy(s.buf, r->value, hash_size); + s.buf += hash_size; + s.len -= hash_size; + } + + if (r->target_value != NULL) { + if (s.len < hash_size) { + return -1; + } + memcpy(s.buf, r->target_value, hash_size); + s.buf += hash_size; + s.len -= hash_size; + } + + if (r->target != NULL) { + int n = encode_string(r->target, s); + if (n < 0) { + return -1; + } + s.buf += n; + s.len -= n; + } + + return start.len - s.len; +} + +static int ref_record_decode(void *rec, struct slice key, byte val_type, + struct slice in, int hash_size) +{ + struct ref_record *r = (struct ref_record *)rec; + struct slice start = in; + bool seen_value = false; + bool seen_target_value = false; + bool seen_target = false; + + int n = get_var_int(&r->update_index, in); + if (n < 0) { + return n; + } + assert(hash_size > 0); + + in.buf += n; + in.len -= n; + + r->ref_name = realloc(r->ref_name, key.len + 1); + memcpy(r->ref_name, key.buf, key.len); + r->ref_name[key.len] = 0; + + switch (val_type) { + case 1: + case 2: + if (in.len < hash_size) { + return -1; + } + + if (r->value == NULL) { + r->value = malloc(hash_size); + } + seen_value = true; + memcpy(r->value, in.buf, hash_size); + in.buf += hash_size; + in.len -= hash_size; + if (val_type == 1) { + break; + } + if (r->target_value == NULL) { + r->target_value = malloc(hash_size); + } + seen_target_value = true; + memcpy(r->target_value, in.buf, hash_size); + in.buf += hash_size; + in.len -= hash_size; + break; + case 3: { + struct slice dest = {}; + int n = decode_string(&dest, in); + if (n < 0) { + return -1; + } + in.buf += n; + in.len -= n; + seen_target = true; + r->target = (char *)slice_as_string(&dest); + } break; + + case 0: + break; + default: + abort(); + break; + } + + if (!seen_target && r->target != NULL) { + FREE_AND_NULL(r->target); + } + if (!seen_target_value && r->target_value != NULL) { + FREE_AND_NULL(r->target_value); + } + if (!seen_value && r->value != NULL) { + FREE_AND_NULL(r->value); + } + + return start.len - in.len; +} + +int decode_key(struct slice *key, byte *extra, struct slice last_key, + struct slice in) +{ + int start_len = in.len; + uint64_t prefix_len = 0; + uint64_t suffix_len = 0; + int n = get_var_int(&prefix_len, in); + if (n < 0) { + return -1; + } + in.buf += n; + in.len -= n; + + if (prefix_len > last_key.len) { + return -1; + } + + n = get_var_int(&suffix_len, in); + if (n <= 0) { + return -1; + } + in.buf += n; + in.len -= n; + + *extra = (byte)(suffix_len & 0x7); + suffix_len >>= 3; + + if (in.len < suffix_len) { + return -1; + } + + slice_resize(key, suffix_len + prefix_len); + memcpy(key->buf, last_key.buf, prefix_len); + + memcpy(key->buf + prefix_len, in.buf, suffix_len); + in.buf += suffix_len; + in.len -= suffix_len; + + return start_len - in.len; +} + +struct record_vtable ref_record_vtable = { + .key = &ref_record_key, + .type = &ref_record_type, + .copy_from = &ref_record_copy_from, + .val_type = &ref_record_val_type, + .encode = &ref_record_encode, + .decode = &ref_record_decode, + .clear = &ref_record_clear_void, +}; + +static byte obj_record_type(void) +{ + return BLOCK_TYPE_OBJ; +} + +static void obj_record_key(const void *r, struct slice *dest) +{ + const struct obj_record *rec = (const struct obj_record *)r; + slice_resize(dest, rec->hash_prefix_len); + memcpy(dest->buf, rec->hash_prefix, rec->hash_prefix_len); +} + +static void obj_record_copy_from(void *rec, const void *src_rec, int hash_size) +{ + struct obj_record *ref = (struct obj_record *)rec; + const struct obj_record *src = (const struct obj_record *)src_rec; + + *ref = *src; + ref->hash_prefix = malloc(ref->hash_prefix_len); + memcpy(ref->hash_prefix, src->hash_prefix, ref->hash_prefix_len); + + { + int olen = ref->offset_len * sizeof(uint64_t); + ref->offsets = malloc(olen); + memcpy(ref->offsets, src->offsets, olen); + } +} + +static void obj_record_clear(void *rec) +{ + struct obj_record *ref = (struct obj_record *)rec; + FREE_AND_NULL(ref->hash_prefix); + FREE_AND_NULL(ref->offsets); + memset(ref, 0, sizeof(struct obj_record)); +} + +static byte obj_record_val_type(const void *rec) +{ + struct obj_record *r = (struct obj_record *)rec; + if (r->offset_len > 0 && r->offset_len < 8) { + return r->offset_len; + } + return 0; +} + +static int obj_record_encode(const void *rec, struct slice s, int hash_size) +{ + struct obj_record *r = (struct obj_record *)rec; + struct slice start = s; + int n = 0; + if (r->offset_len == 0 || r->offset_len >= 8) { + n = put_var_int(s, r->offset_len); + if (n < 0) { + return -1; + } + s.buf += n; + s.len -= n; + } + if (r->offset_len == 0) { + return start.len - s.len; + } + n = put_var_int(s, r->offsets[0]); + if (n < 0) { + return -1; + } + s.buf += n; + s.len -= n; + + { + uint64_t last = r->offsets[0]; + int i = 0; + for (i = 1; i < r->offset_len; i++) { + int n = put_var_int(s, r->offsets[i] - last); + if (n < 0) { + return -1; + } + s.buf += n; + s.len -= n; + last = r->offsets[i]; + } + } + return start.len - s.len; +} + +static int obj_record_decode(void *rec, struct slice key, byte val_type, + struct slice in, int hash_size) +{ + struct slice start = in; + struct obj_record *r = (struct obj_record *)rec; + uint64_t count = val_type; + int n = 0; + r->hash_prefix = malloc(key.len); + memcpy(r->hash_prefix, key.buf, key.len); + r->hash_prefix_len = key.len; + + if (val_type == 0) { + n = get_var_int(&count, in); + if (n < 0) { + return n; + } + + in.buf += n; + in.len -= n; + } + + r->offsets = NULL; + r->offset_len = 0; + if (count == 0) { + return start.len - in.len; + } + + r->offsets = malloc(count * sizeof(uint64_t)); + r->offset_len = count; + + n = get_var_int(&r->offsets[0], in); + if (n < 0) { + return n; + } + + in.buf += n; + in.len -= n; + + { + uint64_t last = r->offsets[0]; + int j = 1; + while (j < count) { + uint64_t delta = 0; + int n = get_var_int(&delta, in); + if (n < 0) { + return n; + } + + in.buf += n; + in.len -= n; + + last = r->offsets[j] = (delta + last); + j++; + } + } + return start.len - in.len; +} + +struct record_vtable obj_record_vtable = { + .key = &obj_record_key, + .type = &obj_record_type, + .copy_from = &obj_record_copy_from, + .val_type = &obj_record_val_type, + .encode = &obj_record_encode, + .decode = &obj_record_decode, + .clear = &obj_record_clear, +}; + +void log_record_print(struct log_record *log, int hash_size) +{ + char hex[SHA256_SIZE + 1] = {}; + + printf("log{%s(%" PRIu64 ") %s <%s> %" PRIu64 " %04d\n", log->ref_name, + log->update_index, log->name, log->email, log->time, + log->tz_offset); + hex_format(hex, log->old_hash, hash_size); + printf("%s => ", hex); + hex_format(hex, log->new_hash, hash_size); + printf("%s\n\n%s\n}\n", hex, log->message); +} + +static byte log_record_type(void) +{ + return BLOCK_TYPE_LOG; +} + +static void log_record_key(const void *r, struct slice *dest) +{ + const struct log_record *rec = (const struct log_record *)r; + int len = strlen(rec->ref_name); + uint64_t ts = 0; + slice_resize(dest, len + 9); + memcpy(dest->buf, rec->ref_name, len + 1); + ts = (~ts) - rec->update_index; + put_u64(dest->buf + 1 + len, ts); +} + +static void log_record_copy_from(void *rec, const void *src_rec, int hash_size) +{ + struct log_record *dst = (struct log_record *)rec; + const struct log_record *src = (const struct log_record *)src_rec; + + *dst = *src; + dst->ref_name = strdup(dst->ref_name); + dst->email = strdup(dst->email); + dst->name = strdup(dst->name); + dst->message = strdup(dst->message); + if (dst->new_hash != NULL) { + dst->new_hash = malloc(hash_size); + memcpy(dst->new_hash, src->new_hash, hash_size); + } + if (dst->old_hash != NULL) { + dst->old_hash = malloc(hash_size); + memcpy(dst->old_hash, src->old_hash, hash_size); + } +} + +static void log_record_clear_void(void *rec) +{ + struct log_record *r = (struct log_record *)rec; + log_record_clear(r); +} + +void log_record_clear(struct log_record *r) +{ + free(r->ref_name); + free(r->new_hash); + free(r->old_hash); + free(r->name); + free(r->email); + free(r->message); + memset(r, 0, sizeof(struct log_record)); +} + +static byte log_record_val_type(const void *rec) +{ + return 1; +} + +static byte zero[SHA256_SIZE] = {}; + +static int log_record_encode(const void *rec, struct slice s, int hash_size) +{ + struct log_record *r = (struct log_record *)rec; + struct slice start = s; + int n = 0; + byte *oldh = r->old_hash; + byte *newh = r->new_hash; + if (oldh == NULL) { + oldh = zero; + } + if (newh == NULL) { + newh = zero; + } + + if (s.len < 2 * hash_size) { + return -1; + } + + memcpy(s.buf, oldh, hash_size); + memcpy(s.buf + hash_size, newh, hash_size); + s.buf += 2 * hash_size; + s.len -= 2 * hash_size; + + n = encode_string(r->name ? r->name : "", s); + if (n < 0) { + return -1; + } + s.len -= n; + s.buf += n; + + n = encode_string(r->email ? r->email : "", s); + if (n < 0) { + return -1; + } + s.len -= n; + s.buf += n; + + n = put_var_int(s, r->time); + if (n < 0) { + return -1; + } + s.buf += n; + s.len -= n; + + if (s.len < 2) { + return -1; + } + + put_u16(s.buf, r->tz_offset); + s.buf += 2; + s.len -= 2; + + n = encode_string(r->message ? r->message : "", s); + if (n < 0) { + return -1; + } + s.len -= n; + s.buf += n; + + return start.len - s.len; +} + +static int log_record_decode(void *rec, struct slice key, byte val_type, + struct slice in, int hash_size) +{ + struct slice start = in; + struct log_record *r = (struct log_record *)rec; + uint64_t max = 0; + uint64_t ts = 0; + struct slice dest = {}; + int n; + + if (key.len <= 9 || key.buf[key.len - 9] != 0) { + return FORMAT_ERROR; + } + + r->ref_name = realloc(r->ref_name, key.len - 8); + memcpy(r->ref_name, key.buf, key.len - 8); + ts = get_u64(key.buf + key.len - 8); + + r->update_index = (~max) - ts; + + if (in.len < 2 * hash_size) { + return FORMAT_ERROR; + } + + r->old_hash = realloc(r->old_hash, hash_size); + r->new_hash = realloc(r->new_hash, hash_size); + + memcpy(r->old_hash, in.buf, hash_size); + memcpy(r->new_hash, in.buf + hash_size, hash_size); + + in.buf += 2 * hash_size; + in.len -= 2 * hash_size; + + n = decode_string(&dest, in); + if (n < 0) { + goto error; + } + in.len -= n; + in.buf += n; + + r->name = realloc(r->name, dest.len + 1); + memcpy(r->name, dest.buf, dest.len); + r->name[dest.len] = 0; + + slice_resize(&dest, 0); + n = decode_string(&dest, in); + if (n < 0) { + goto error; + } + in.len -= n; + in.buf += n; + + r->email = realloc(r->email, dest.len + 1); + memcpy(r->email, dest.buf, dest.len); + r->email[dest.len] = 0; + + ts = 0; + n = get_var_int(&ts, in); + if (n < 0) { + goto error; + } + in.len -= n; + in.buf += n; + r->time = ts; + if (in.len < 2) { + goto error; + } + + r->tz_offset = get_u16(in.buf); + in.buf += 2; + in.len -= 2; + + slice_resize(&dest, 0); + n = decode_string(&dest, in); + if (n < 0) { + goto error; + } + in.len -= n; + in.buf += n; + + r->message = realloc(r->message, dest.len + 1); + memcpy(r->message, dest.buf, dest.len); + r->message[dest.len] = 0; + + return start.len - in.len; + +error: + free(slice_yield(&dest)); + return FORMAT_ERROR; +} + +static bool null_streq(char *a, char *b) +{ + char *empty = ""; + if (a == NULL) { + a = empty; + } + if (b == NULL) { + b = empty; + } + return 0 == strcmp(a, b); +} + +static bool zero_hash_eq(byte *a, byte *b, int sz) +{ + if (a == NULL) { + a = zero; + } + if (b == NULL) { + b = zero; + } + return !memcmp(a, b, sz); +} + +bool log_record_equal(struct log_record *a, struct log_record *b, int hash_size) +{ + return null_streq(a->name, b->name) && null_streq(a->email, b->email) && + null_streq(a->message, b->message) && + zero_hash_eq(a->old_hash, b->old_hash, hash_size) && + zero_hash_eq(a->new_hash, b->new_hash, hash_size) && + a->time == b->time && a->tz_offset == b->tz_offset && + a->update_index == b->update_index; +} + +struct record_vtable log_record_vtable = { + .key = &log_record_key, + .type = &log_record_type, + .copy_from = &log_record_copy_from, + .val_type = &log_record_val_type, + .encode = &log_record_encode, + .decode = &log_record_decode, + .clear = &log_record_clear_void, +}; + +struct record new_record(byte typ) +{ + struct record rec; + switch (typ) { + case BLOCK_TYPE_REF: { + struct ref_record *r = calloc(1, sizeof(struct ref_record)); + record_from_ref(&rec, r); + return rec; + } + + case BLOCK_TYPE_OBJ: { + struct obj_record *r = calloc(1, sizeof(struct obj_record)); + record_from_obj(&rec, r); + return rec; + } + case BLOCK_TYPE_LOG: { + struct log_record *r = calloc(1, sizeof(struct log_record)); + record_from_log(&rec, r); + return rec; + } + case BLOCK_TYPE_INDEX: { + struct index_record *r = calloc(1, sizeof(struct index_record)); + record_from_index(&rec, r); + return rec; + } + } + abort(); + return rec; +} + +static byte index_record_type(void) +{ + return BLOCK_TYPE_INDEX; +} + +static void index_record_key(const void *r, struct slice *dest) +{ + struct index_record *rec = (struct index_record *)r; + slice_copy(dest, rec->last_key); +} + +static void index_record_copy_from(void *rec, const void *src_rec, + int hash_size) +{ + struct index_record *dst = (struct index_record *)rec; + struct index_record *src = (struct index_record *)src_rec; + + slice_copy(&dst->last_key, src->last_key); + dst->offset = src->offset; +} + +static void index_record_clear(void *rec) +{ + struct index_record *idx = (struct index_record *)rec; + free(slice_yield(&idx->last_key)); +} + +static byte index_record_val_type(const void *rec) +{ + return 0; +} + +static int index_record_encode(const void *rec, struct slice out, int hash_size) +{ + const struct index_record *r = (const struct index_record *)rec; + struct slice start = out; + + int n = put_var_int(out, r->offset); + if (n < 0) { + return n; + } + + out.buf += n; + out.len -= n; + + return start.len - out.len; +} + +static int index_record_decode(void *rec, struct slice key, byte val_type, + struct slice in, int hash_size) +{ + struct slice start = in; + struct index_record *r = (struct index_record *)rec; + int n = 0; + + slice_copy(&r->last_key, key); + + n = get_var_int(&r->offset, in); + if (n < 0) { + return n; + } + + in.buf += n; + in.len -= n; + return start.len - in.len; +} + +struct record_vtable index_record_vtable = { + .key = &index_record_key, + .type = &index_record_type, + .copy_from = &index_record_copy_from, + .val_type = &index_record_val_type, + .encode = &index_record_encode, + .decode = &index_record_decode, + .clear = &index_record_clear, +}; + +void record_key(struct record rec, struct slice *dest) +{ + rec.ops->key(rec.data, dest); +} + +byte record_type(struct record rec) +{ + return rec.ops->type(); +} + +int record_encode(struct record rec, struct slice dest, int hash_size) +{ + return rec.ops->encode(rec.data, dest, hash_size); +} + +void record_copy_from(struct record rec, struct record src, int hash_size) +{ + assert(src.ops->type() == rec.ops->type()); + + rec.ops->copy_from(rec.data, src.data, hash_size); +} + +byte record_val_type(struct record rec) +{ + return rec.ops->val_type(rec.data); +} + +int record_decode(struct record rec, struct slice key, byte extra, + struct slice src, int hash_size) +{ + return rec.ops->decode(rec.data, key, extra, src, hash_size); +} + +void record_clear(struct record rec) +{ + return rec.ops->clear(rec.data); +} + +void record_from_ref(struct record *rec, struct ref_record *ref_rec) +{ + rec->data = ref_rec; + rec->ops = &ref_record_vtable; +} + +void record_from_obj(struct record *rec, struct obj_record *obj_rec) +{ + rec->data = obj_rec; + rec->ops = &obj_record_vtable; +} + +void record_from_index(struct record *rec, struct index_record *index_rec) +{ + rec->data = index_rec; + rec->ops = &index_record_vtable; +} + +void record_from_log(struct record *rec, struct log_record *log_rec) +{ + rec->data = log_rec; + rec->ops = &log_record_vtable; +} + +void *record_yield(struct record *rec) +{ + void *p = rec->data; + rec->data = NULL; + return p; +} + +struct ref_record *record_as_ref(struct record rec) +{ + assert(record_type(rec) == BLOCK_TYPE_REF); + return (struct ref_record *)rec.data; +} + +static bool hash_equal(byte *a, byte *b, int hash_size) +{ + if (a != NULL && b != NULL) { + return !memcmp(a, b, hash_size); + } + + return a == b; +} + +static bool str_equal(char *a, char *b) +{ + if (a != NULL && b != NULL) { + return 0 == strcmp(a, b); + } + + return a == b; +} + +bool ref_record_equal(struct ref_record *a, struct ref_record *b, int hash_size) +{ + assert(hash_size > 0); + return 0 == strcmp(a->ref_name, b->ref_name) && + a->update_index == b->update_index && + hash_equal(a->value, b->value, hash_size) && + hash_equal(a->target_value, b->target_value, hash_size) && + str_equal(a->target, b->target); +} + +int ref_record_compare_name(const void *a, const void *b) +{ + return strcmp(((struct ref_record *)a)->ref_name, + ((struct ref_record *)b)->ref_name); +} + +bool ref_record_is_deletion(const struct ref_record *ref) +{ + return ref->value == NULL && ref->target == NULL && + ref->target_value == NULL; +} + +int log_record_compare_key(const void *a, const void *b) +{ + struct log_record *la = (struct log_record *)a; + struct log_record *lb = (struct log_record *)b; + + int cmp = strcmp(la->ref_name, lb->ref_name); + if (cmp) { + return cmp; + } + if (la->update_index > lb->update_index) { + return -1; + } + return (la->update_index < lb->update_index) ? 1 : 0; +} + +bool log_record_is_deletion(const struct log_record *log) +{ + /* XXX */ + return false; +} diff --git a/reftable/record.h b/reftable/record.h new file mode 100644 index 0000000000..dffdd71fc2 --- /dev/null +++ b/reftable/record.h @@ -0,0 +1,79 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef RECORD_H +#define RECORD_H + +#include "reftable.h" +#include "slice.h" + +struct record_vtable { + void (*key)(const void *rec, struct slice *dest); + byte (*type)(void); + void (*copy_from)(void *rec, const void *src, int hash_size); + byte (*val_type)(const void *rec); + int (*encode)(const void *rec, struct slice dest, int hash_size); + int (*decode)(void *rec, struct slice key, byte extra, struct slice src, + int hash_size); + void (*clear)(void *rec); +}; + +/* record is a generic wrapper for differnt types of records. */ +struct record { + void *data; + struct record_vtable *ops; +}; + +int get_var_int(uint64_t *dest, struct slice in); +int put_var_int(struct slice dest, uint64_t val); +int common_prefix_size(struct slice a, struct slice b); + +int is_block_type(byte typ); +struct record new_record(byte typ); + +extern struct record_vtable ref_record_vtable; + +int encode_key(bool *restart, struct slice dest, struct slice prev_key, + struct slice key, byte extra); +int decode_key(struct slice *key, byte *extra, struct slice last_key, + struct slice in); + +struct index_record { + struct slice last_key; + uint64_t offset; +}; + +struct obj_record { + byte *hash_prefix; + int hash_prefix_len; + uint64_t *offsets; + int offset_len; +}; + +void record_key(struct record rec, struct slice *dest); +byte record_type(struct record rec); +void record_copy_from(struct record rec, struct record src, int hash_size); +byte record_val_type(struct record rec); +int record_encode(struct record rec, struct slice dest, int hash_size); +int record_decode(struct record rec, struct slice key, byte extra, + struct slice src, int hash_size); +void record_clear(struct record rec); +void *record_yield(struct record *rec); +void record_from_obj(struct record *rec, struct obj_record *objrec); +void record_from_index(struct record *rec, struct index_record *idxrec); +void record_from_ref(struct record *rec, struct ref_record *refrec); +void record_from_log(struct record *rec, struct log_record *logrec); +struct ref_record *record_as_ref(struct record ref); + +/* for qsort. */ +int ref_record_compare_name(const void *a, const void *b); + +/* for qsort. */ +int log_record_compare_key(const void *a, const void *b); + +#endif diff --git a/reftable/reftable.h b/reftable/reftable.h new file mode 100644 index 0000000000..d84cc2004a --- /dev/null +++ b/reftable/reftable.h @@ -0,0 +1,399 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef REFTABLE_H +#define REFTABLE_H + +#include "system.h" + +typedef uint8_t byte; +typedef byte bool; + +/* block_source is a generic wrapper for a seekable readable file. + It is generally passed around by value. + */ +struct block_source { + struct block_source_vtable *ops; + void *arg; +}; + +/* a contiguous segment of bytes. It keeps track of its generating block_source + so it can return itself into the pool. +*/ +struct block { + byte *data; + int len; + struct block_source source; +}; + +/* block_source_vtable are the operations that make up block_source */ +struct block_source_vtable { + /* returns the size of a block source */ + uint64_t (*size)(void *source); + + /* reads a segment from the block source. It is an error to read + beyond the end of the block */ + int (*read_block)(void *source, struct block *dest, uint64_t off, + uint32_t size); + /* mark the block as read; may return the data back to malloc */ + void (*return_block)(void *source, struct block *blockp); + + /* release all resources associated with the block source */ + void (*close)(void *source); +}; + +/* opens a file on the file system as a block_source */ +int block_source_from_file(struct block_source *block_src, const char *name); + +/* write_options sets options for writing a single reftable. */ +struct write_options { + /* do not pad out blocks to block size. */ + bool unpadded; + + /* the blocksize. Should be less than 2^24. */ + uint32_t block_size; + + /* do not generate a SHA1 => ref index. */ + bool skip_index_objects; + + /* how often to write complete keys in each block. */ + int restart_interval; +}; + +/* ref_record holds a ref database entry target_value */ +struct ref_record { + char *ref_name; /* Name of the ref, malloced. */ + uint64_t update_index; /* Logical timestamp at which this value is + written */ + byte *value; /* SHA1, or NULL. malloced. */ + byte *target_value; /* peeled annotated tag, or NULL. malloced. */ + char *target; /* symref, or NULL. malloced. */ +}; + +/* returns whether 'ref' represents a deletion */ +bool ref_record_is_deletion(const struct ref_record *ref); + +/* prints a ref_record onto stdout */ +void ref_record_print(struct ref_record *ref, int hash_size); + +/* frees and nulls all pointer values. */ +void ref_record_clear(struct ref_record *ref); + +/* returns whether two ref_records are the same */ +bool ref_record_equal(struct ref_record *a, struct ref_record *b, + int hash_size); + +/* log_record holds a reflog entry */ +struct log_record { + char *ref_name; + uint64_t update_index; + byte *new_hash; + byte *old_hash; + char *name; + char *email; + uint64_t time; + int16_t tz_offset; + char *message; +}; + +/* returns whether 'ref' represents the deletion of a log record. */ +bool log_record_is_deletion(const struct log_record *log); + +/* frees and nulls all pointer values. */ +void log_record_clear(struct log_record *log); + +/* returns whether two records are equal. */ +bool log_record_equal(struct log_record *a, struct log_record *b, + int hash_size); + +void log_record_print(struct log_record *log, int hash_size); + +/* iterator is the generic interface for walking over data stored in a + reftable. It is generally passed around by value. +*/ +struct iterator { + struct iterator_vtable *ops; + void *iter_arg; +}; + +/* reads the next ref_record. Returns < 0 for error, 0 for OK and > 0: + end of iteration. +*/ +int iterator_next_ref(struct iterator it, struct ref_record *ref); + +/* reads the next log_record. Returns < 0 for error, 0 for OK and > 0: + end of iteration. +*/ +int iterator_next_log(struct iterator it, struct log_record *log); + +/* releases resources associated with an iterator. */ +void iterator_destroy(struct iterator *it); + +/* block_stats holds statistics for a single block type */ +struct block_stats { + /* total number of entries written */ + int entries; + /* total number of key restarts */ + int restarts; + /* total number of blocks */ + int blocks; + /* total number of index blocks */ + int index_blocks; + /* depth of the index */ + int max_index_level; + + /* offset of the first block for this type */ + uint64_t offset; + /* offset of the top level index block for this type, or 0 if not + * present */ + uint64_t index_offset; +}; + +/* stats holds overall statistics for a single reftable */ +struct stats { + /* total number of blocks written. */ + int blocks; + /* stats for ref data */ + struct block_stats ref_stats; + /* stats for the SHA1 to ref map. */ + struct block_stats obj_stats; + /* stats for index blocks */ + struct block_stats idx_stats; + /* stats for log blocks */ + struct block_stats log_stats; + + /* disambiguation length of shortened object IDs. */ + int object_id_len; +}; + +/* different types of errors */ + +/* Unexpected file system behavior */ +#define IO_ERROR -2 + +/* Format inconsistency on reading data + */ +#define FORMAT_ERROR -3 + +/* File does not exist. Returned from block_source_from_file(), because it + needs special handling in stack. +*/ +#define NOT_EXIST_ERROR -4 + +/* Trying to write out-of-date data. */ +#define LOCK_ERROR -5 + +/* Misuse of the API: + - on writing a record with NULL ref_name. + - on writing a ref_record outside the table limits + - on writing a ref or log record before the stack's next_update_index + - on reading a ref_record from log iterator, or vice versa. + */ +#define API_ERROR -6 + +/* Decompression error */ +#define ZLIB_ERROR -7 + +const char *error_str(int err); + +/* new_writer creates a new writer */ +struct writer *new_writer(int (*writer_func)(void *, byte *, int), + void *writer_arg, struct write_options *opts); + +/* write to a file descriptor. fdp should be an int* pointing to the fd. */ +int fd_writer(void *fdp, byte *data, int size); + +/* Set the range of update indices for the records we will add. When + writing a table into a stack, the min should be at least + stack_next_update_index(), or API_ERROR is returned. + */ +void writer_set_limits(struct writer *w, uint64_t min, uint64_t max); + +/* adds a ref_record. Must be called in ascending + order. The update_index must be within the limits set by + writer_set_limits(), or API_ERROR is returned. + */ +int writer_add_ref(struct writer *w, struct ref_record *ref); + +/* Convenience function to add multiple refs. Will sort the refs by + name before adding. */ +int writer_add_refs(struct writer *w, struct ref_record *refs, int n); + +/* adds a log_record. Must be called in ascending order (with more + recent log entries first.) + */ +int writer_add_log(struct writer *w, struct log_record *log); + +/* Convenience function to add multiple logs. Will sort the records by + key before adding. */ +int writer_add_logs(struct writer *w, struct log_record *logs, int n); + +/* writer_close finalizes the reftable. The writer is retained so statistics can + * be inspected. */ +int writer_close(struct writer *w); + +/* writer_stats returns the statistics on the reftable being written. */ +struct stats *writer_stats(struct writer *w); + +/* writer_free deallocates memory for the writer */ +void writer_free(struct writer *w); + +struct reader; + +/* new_reader opens a reftable for reading. If successful, returns 0 + * code and sets pp. The name is used for creating a + * stack. Typically, it is the basename of the file. + */ +int new_reader(struct reader **pp, struct block_source, const char *name); + +/* reader_seek_ref returns an iterator where 'name' would be inserted in the + table. + + example: + + struct reader *r = NULL; + int err = new_reader(&r, src, "filename"); + if (err < 0) { ... } + struct iterator it = {}; + err = reader_seek_ref(r, &it, "refs/heads/master"); + if (err < 0) { ... } + struct ref_record ref = {}; + while (1) { + err = iterator_next_ref(it, &ref); + if (err > 0) { + break; + } + if (err < 0) { + ..error handling.. + } + ..found.. + } + iterator_destroy(&it); + ref_record_clear(&ref); + */ +int reader_seek_ref(struct reader *r, struct iterator *it, const char *name); + +/* seek to logs for the given name, older than update_index. */ +int reader_seek_log_at(struct reader *r, struct iterator *it, const char *name, + uint64_t update_index); + +/* seek to newest log entry for given name. */ +int reader_seek_log(struct reader *r, struct iterator *it, const char *name); + +/* closes and deallocates a reader. */ +void reader_free(struct reader *); + +/* return an iterator for the refs pointing to oid */ +int reader_refs_for(struct reader *r, struct iterator *it, byte *oid, + int oid_len); + +/* return the max_update_index for a table */ +uint64_t reader_max_update_index(struct reader *r); + +/* return the min_update_index for a table */ +uint64_t reader_min_update_index(struct reader *r); + +/* a merged table is implements seeking/iterating over a stack of tables. */ +struct merged_table; + +/* new_merged_table creates a new merged table. It takes ownership of the stack + array. +*/ +int new_merged_table(struct merged_table **dest, struct reader **stack, int n); + +/* returns an iterator positioned just before 'name' */ +int merged_table_seek_ref(struct merged_table *mt, struct iterator *it, + const char *name); + +/* returns an iterator for log entry, at given update_index */ +int merged_table_seek_log_at(struct merged_table *mt, struct iterator *it, + const char *name, uint64_t update_index); + +/* like merged_table_seek_log_at but look for the newest entry. */ +int merged_table_seek_log(struct merged_table *mt, struct iterator *it, + const char *name); + +/* returns the max update_index covered by this merged table. */ +uint64_t merged_max_update_index(struct merged_table *mt); + +/* returns the min update_index covered by this merged table. */ +uint64_t merged_min_update_index(struct merged_table *mt); + +/* closes readers for the merged tables */ +void merged_table_close(struct merged_table *mt); + +/* releases memory for the merged_table */ +void merged_table_free(struct merged_table *m); + +/* a stack is a stack of reftables, which can be mutated by pushing a table to + * the top of the stack */ +struct stack; + +/* open a new reftable stack. The tables will be stored in 'dir', while the list + of tables is in 'list_file'. Typically, this should be .git/reftables and + .git/refs respectively. +*/ +int new_stack(struct stack **dest, const char *dir, const char *list_file, + struct write_options config); + +/* returns the update_index at which a next table should be written. */ +uint64_t stack_next_update_index(struct stack *st); + +/* add a new table to the stack. The write_table function must call + writer_set_limits, add refs and return an error value. */ +int stack_add(struct stack *st, + int (*write_table)(struct writer *wr, void *write_arg), + void *write_arg); + +/* returns the merged_table for seeking. This table is valid until the + next write or reload, and should not be closed or deleted. +*/ +struct merged_table *stack_merged_table(struct stack *st); + +/* frees all resources associated with the stack. */ +void stack_destroy(struct stack *st); + +/* reloads the stack if necessary. */ +int stack_reload(struct stack *st); + +/* Policy for expiring reflog entries. */ +struct log_expiry_config { + /* Drop entries older than this timestamp */ + uint64_t time; + + /* Drop older entries */ + uint64_t min_update_index; +}; + +/* compacts all reftables into a giant table. Expire reflog entries if config is + * non-NULL */ +int stack_compact_all(struct stack *st, struct log_expiry_config *config); + +/* heuristically compact unbalanced table stack. */ +int stack_auto_compact(struct stack *st); + +/* convenience function to read a single ref. Returns < 0 for error, 0 + for success, and 1 if ref not found. */ +int stack_read_ref(struct stack *st, const char *refname, + struct ref_record *ref); + +/* convenience function to read a single log. Returns < 0 for error, 0 + for success, and 1 if ref not found. */ +int stack_read_log(struct stack *st, const char *refname, + struct log_record *log); + +/* statistics on past compactions. */ +struct compaction_stats { + uint64_t bytes; + int attempts; + int failures; +}; + +struct compaction_stats *stack_compaction_stats(struct stack *st); + +#endif diff --git a/reftable/slice.c b/reftable/slice.c new file mode 100644 index 0000000000..efbe625253 --- /dev/null +++ b/reftable/slice.c @@ -0,0 +1,199 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#include "slice.h" + +#include "system.h" + +#include "reftable.h" + +void slice_set_string(struct slice *s, const char *str) +{ + if (str == NULL) { + s->len = 0; + return; + } + + { + int l = strlen(str); + l++; /* \0 */ + slice_resize(s, l); + memcpy(s->buf, str, l); + s->len = l - 1; + } +} + +void slice_resize(struct slice *s, int l) +{ + if (s->cap < l) { + int c = s->cap * 2; + if (c < l) { + c = l; + } + s->cap = c; + s->buf = realloc(s->buf, s->cap); + } + s->len = l; +} + +void slice_append_string(struct slice *d, const char *s) +{ + int l1 = d->len; + int l2 = strlen(s); + + slice_resize(d, l2 + l1); + memcpy(d->buf + l1, s, l2); +} + +void slice_append(struct slice *s, struct slice a) +{ + int end = s->len; + slice_resize(s, s->len + a.len); + memcpy(s->buf + end, a.buf, a.len); +} + +byte *slice_yield(struct slice *s) +{ + byte *p = s->buf; + s->buf = NULL; + s->cap = 0; + s->len = 0; + return p; +} + +void slice_copy(struct slice *dest, struct slice src) +{ + slice_resize(dest, src.len); + memcpy(dest->buf, src.buf, src.len); +} + +/* return the underlying data as char*. len is left unchanged, but + a \0 is added at the end. */ +const char *slice_as_string(struct slice *s) +{ + if (s->cap == s->len) { + int l = s->len; + slice_resize(s, l + 1); + s->len = l; + } + s->buf[s->len] = 0; + return (const char *)s->buf; +} + +/* return a newly malloced string for this slice */ +char *slice_to_string(struct slice in) +{ + struct slice s = {}; + slice_resize(&s, in.len + 1); + s.buf[in.len] = 0; + memcpy(s.buf, in.buf, in.len); + return (char *)slice_yield(&s); +} + +bool slice_equal(struct slice a, struct slice b) +{ + if (a.len != b.len) { + return 0; + } + return memcmp(a.buf, b.buf, a.len) == 0; +} + +int slice_compare(struct slice a, struct slice b) +{ + int min = a.len < b.len ? a.len : b.len; + int res = memcmp(a.buf, b.buf, min); + if (res != 0) { + return res; + } + if (a.len < b.len) { + return -1; + } else if (a.len > b.len) { + return 1; + } else { + return 0; + } +} + +int slice_write(struct slice *b, byte *data, int sz) +{ + if (b->len + sz > b->cap) { + int newcap = 2 * b->cap + 1; + if (newcap < b->len + sz) { + newcap = (b->len + sz); + } + b->buf = realloc(b->buf, newcap); + b->cap = newcap; + } + + memcpy(b->buf + b->len, data, sz); + b->len += sz; + return sz; +} + +int slice_write_void(void *b, byte *data, int sz) +{ + return slice_write((struct slice *)b, data, sz); +} + +static uint64_t slice_size(void *b) +{ + return ((struct slice *)b)->len; +} + +static void slice_return_block(void *b, struct block *dest) +{ + memset(dest->data, 0xff, dest->len); + free(dest->data); +} + +static void slice_close(void *b) +{ +} + +static int slice_read_block(void *v, struct block *dest, uint64_t off, + uint32_t size) +{ + struct slice *b = (struct slice *)v; + assert(off + size <= b->len); + dest->data = calloc(size, 1); + memcpy(dest->data, b->buf + off, size); + dest->len = size; + return size; +} + +struct block_source_vtable slice_vtable = { + .size = &slice_size, + .read_block = &slice_read_block, + .return_block = &slice_return_block, + .close = &slice_close, +}; + +void block_source_from_slice(struct block_source *bs, struct slice *buf) +{ + bs->ops = &slice_vtable; + bs->arg = buf; +} + +static void malloc_return_block(void *b, struct block *dest) +{ + memset(dest->data, 0xff, dest->len); + free(dest->data); +} + +struct block_source_vtable malloc_vtable = { + .return_block = &malloc_return_block, +}; + +struct block_source malloc_block_source_instance = { + .ops = &malloc_vtable, +}; + +struct block_source malloc_block_source(void) +{ + return malloc_block_source_instance; +} diff --git a/reftable/slice.h b/reftable/slice.h new file mode 100644 index 0000000000..f12a6db228 --- /dev/null +++ b/reftable/slice.h @@ -0,0 +1,39 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef SLICE_H +#define SLICE_H + +#include "basics.h" +#include "reftable.h" + +struct slice { + byte *buf; + int len; + int cap; +}; + +void slice_set_string(struct slice *dest, const char *); +void slice_append_string(struct slice *dest, const char *); +char *slice_to_string(struct slice src); +const char *slice_as_string(struct slice *src); +bool slice_equal(struct slice a, struct slice b); +byte *slice_yield(struct slice *s); +void slice_copy(struct slice *dest, struct slice src); +void slice_resize(struct slice *s, int l); +int slice_compare(struct slice a, struct slice b); +int slice_write(struct slice *b, byte *data, int sz); +int slice_write_void(void *b, byte *data, int sz); +void slice_append(struct slice *dest, struct slice add); + +struct block_source; +void block_source_from_slice(struct block_source *bs, struct slice *buf); + +struct block_source malloc_block_source(void); + +#endif diff --git a/reftable/stack.c b/reftable/stack.c new file mode 100644 index 0000000000..303eed2f37 --- /dev/null +++ b/reftable/stack.c @@ -0,0 +1,983 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#include "stack.h" + +#include "system.h" +#include "merged.h" +#include "reader.h" +#include "reftable.h" +#include "writer.h" + +int new_stack(struct stack **dest, const char *dir, const char *list_file, + struct write_options config) +{ + struct stack *p = calloc(sizeof(struct stack), 1); + int err = 0; + *dest = NULL; + p->list_file = strdup(list_file); + p->reftable_dir = strdup(dir); + p->config = config; + + err = stack_reload(p); + if (err < 0) { + stack_destroy(p); + } else { + *dest = p; + } + return err; +} + +static int fread_lines(FILE *f, char ***namesp) +{ + long size = 0; + int err = fseek(f, 0, SEEK_END); + char *buf = NULL; + if (err < 0) { + err = IO_ERROR; + goto exit; + } + size = ftell(f); + if (size < 0) { + err = IO_ERROR; + goto exit; + } + err = fseek(f, 0, SEEK_SET); + if (err < 0) { + err = IO_ERROR; + goto exit; + } + + buf = malloc(size + 1); + if (fread(buf, 1, size, f) != size) { + err = IO_ERROR; + goto exit; + } + buf[size] = 0; + + parse_names(buf, size, namesp); +exit: + free(buf); + return err; +} + +int read_lines(const char *filename, char ***namesp) +{ + FILE *f = fopen(filename, "r"); + int err = 0; + if (f == NULL) { + if (errno == ENOENT) { + *namesp = calloc(sizeof(char *), 1); + return 0; + } + + return IO_ERROR; + } + err = fread_lines(f, namesp); + fclose(f); + return err; +} + +struct merged_table *stack_merged_table(struct stack *st) +{ + return st->merged; +} + +/* Close and free the stack */ +void stack_destroy(struct stack *st) +{ + if (st->merged == NULL) { + return; + } + + merged_table_close(st->merged); + merged_table_free(st->merged); + st->merged = NULL; + + FREE_AND_NULL(st->list_file); + FREE_AND_NULL(st->reftable_dir); + free(st); +} + +static struct reader **stack_copy_readers(struct stack *st, int cur_len) +{ + struct reader **cur = calloc(sizeof(struct reader *), cur_len); + int i = 0; + for (i = 0; i < cur_len; i++) { + cur[i] = st->merged->stack[i]; + } + return cur; +} + +static int stack_reload_once(struct stack *st, char **names, bool reuse_open) +{ + int cur_len = st->merged == NULL ? 0 : st->merged->stack_len; + struct reader **cur = stack_copy_readers(st, cur_len); + int err = 0; + int names_len = names_length(names); + struct reader **new_tables = + malloc(sizeof(struct reader *) * names_len); + int new_tables_len = 0; + struct merged_table *new_merged = NULL; + + struct slice table_path = {}; + + while (*names) { + struct reader *rd = NULL; + char *name = *names++; + + /* this is linear; we assume compaction keeps the number of + tables under control so this is not quadratic. */ + int j = 0; + for (j = 0; reuse_open && j < cur_len; j++) { + if (cur[j] != NULL && 0 == strcmp(cur[j]->name, name)) { + rd = cur[j]; + cur[j] = NULL; + break; + } + } + + if (rd == NULL) { + struct block_source src = {}; + slice_set_string(&table_path, st->reftable_dir); + slice_append_string(&table_path, "/"); + slice_append_string(&table_path, name); + + err = block_source_from_file( + &src, slice_as_string(&table_path)); + if (err < 0) { + goto exit; + } + + err = new_reader(&rd, src, name); + if (err < 0) { + goto exit; + } + } + + new_tables[new_tables_len++] = rd; + } + + /* success! */ + err = new_merged_table(&new_merged, new_tables, new_tables_len); + if (err < 0) { + goto exit; + } + + new_tables = NULL; + new_tables_len = 0; + if (st->merged != NULL) { + merged_table_clear(st->merged); + merged_table_free(st->merged); + } + st->merged = new_merged; + + { + int i = 0; + for (i = 0; i < cur_len; i++) { + if (cur[i] != NULL) { + reader_close(cur[i]); + reader_free(cur[i]); + } + } + } +exit: + free(slice_yield(&table_path)); + { + int i = 0; + for (i = 0; i < new_tables_len; i++) { + reader_close(new_tables[i]); + } + } + free(new_tables); + free(cur); + return err; +} + +/* return negative if a before b. */ +static int tv_cmp(struct timeval *a, struct timeval *b) +{ + time_t diff = a->tv_sec - b->tv_sec; + int udiff = a->tv_usec - b->tv_usec; + + if (diff != 0) { + return diff; + } + + return udiff; +} + +static int stack_reload_maybe_reuse(struct stack *st, bool reuse_open) +{ + struct timeval deadline = {}; + int err = gettimeofday(&deadline, NULL); + int64_t delay = 0; + int tries = 0; + if (err < 0) { + return err; + } + + deadline.tv_sec += 3; + while (true) { + char **names = NULL; + char **names_after = NULL; + struct timeval now = {}; + int err = gettimeofday(&now, NULL); + if (err < 0) { + return err; + } + + /* Only look at deadlines after the first few times. This + simplifies debugging in GDB */ + tries++; + if (tries > 3 && tv_cmp(&now, &deadline) >= 0) { + break; + } + + err = read_lines(st->list_file, &names); + if (err < 0) { + free_names(names); + return err; + } + err = stack_reload_once(st, names, reuse_open); + if (err == 0) { + free_names(names); + break; + } + if (err != NOT_EXIST_ERROR) { + free_names(names); + return err; + } + + err = read_lines(st->list_file, &names_after); + if (err < 0) { + free_names(names); + return err; + } + + if (names_equal(names_after, names)) { + free_names(names); + free_names(names_after); + return -1; + } + free_names(names); + free_names(names_after); + + delay = delay + (delay * rand()) / RAND_MAX + 100; + usleep(delay); + } + + return 0; +} + +int stack_reload(struct stack *st) +{ + return stack_reload_maybe_reuse(st, true); +} + +/* -1 = error + 0 = up to date + 1 = changed. */ +static int stack_uptodate(struct stack *st) +{ + char **names = NULL; + int err = read_lines(st->list_file, &names); + int i = 0; + if (err < 0) { + return err; + } + + for (i = 0; i < st->merged->stack_len; i++) { + if (names[i] == NULL) { + err = 1; + goto exit; + } + + if (strcmp(st->merged->stack[i]->name, names[i])) { + err = 1; + goto exit; + } + } + + if (names[st->merged->stack_len] != NULL) { + err = 1; + goto exit; + } + +exit: + free_names(names); + return err; +} + +int stack_add(struct stack *st, int (*write)(struct writer *wr, void *arg), + void *arg) +{ + int err = stack_try_add(st, write, arg); + if (err < 0) { + if (err == LOCK_ERROR) { + err = stack_reload(st); + } + return err; + } + + return stack_auto_compact(st); +} + +static void format_name(struct slice *dest, uint64_t min, uint64_t max) +{ + char buf[100]; + snprintf(buf, sizeof(buf), "%012" PRIx64 "-%012" PRIx64, min, max); + slice_set_string(dest, buf); +} + +int stack_try_add(struct stack *st, + int (*write_table)(struct writer *wr, void *arg), void *arg) +{ + struct slice lock_name = {}; + struct slice temp_tab_name = {}; + struct slice tab_name = {}; + struct slice next_name = {}; + struct slice table_list = {}; + struct writer *wr = NULL; + int err = 0; + int tab_fd = 0; + int lock_fd = 0; + uint64_t next_update_index = 0; + + slice_set_string(&lock_name, st->list_file); + slice_append_string(&lock_name, ".lock"); + + lock_fd = open(slice_as_string(&lock_name), O_EXCL | O_CREAT | O_WRONLY, + 0644); + if (lock_fd < 0) { + if (errno == EEXIST) { + err = LOCK_ERROR; + goto exit; + } + err = IO_ERROR; + goto exit; + } + + err = stack_uptodate(st); + if (err < 0) { + goto exit; + } + + if (err > 1) { + err = LOCK_ERROR; + goto exit; + } + + next_update_index = stack_next_update_index(st); + + slice_resize(&next_name, 0); + format_name(&next_name, next_update_index, next_update_index); + + slice_set_string(&temp_tab_name, st->reftable_dir); + slice_append_string(&temp_tab_name, "/"); + slice_append(&temp_tab_name, next_name); + slice_append_string(&temp_tab_name, ".temp.XXXXXX"); + + tab_fd = mkstemp((char *)slice_as_string(&temp_tab_name)); + if (tab_fd < 0) { + err = IO_ERROR; + goto exit; + } + + wr = new_writer(fd_writer, &tab_fd, &st->config); + err = write_table(wr, arg); + if (err < 0) { + goto exit; + } + + err = writer_close(wr); + if (err < 0) { + goto exit; + } + + err = close(tab_fd); + tab_fd = 0; + if (err < 0) { + err = IO_ERROR; + goto exit; + } + + if (wr->min_update_index < next_update_index) { + err = API_ERROR; + goto exit; + } + + { + int i = 0; + for (i = 0; i < st->merged->stack_len; i++) { + slice_append_string(&table_list, + st->merged->stack[i]->name); + slice_append_string(&table_list, "\n"); + } + } + + format_name(&next_name, wr->min_update_index, wr->max_update_index); + slice_append_string(&next_name, ".ref"); + slice_append(&table_list, next_name); + slice_append_string(&table_list, "\n"); + + slice_set_string(&tab_name, st->reftable_dir); + slice_append_string(&tab_name, "/"); + slice_append(&tab_name, next_name); + + err = rename(slice_as_string(&temp_tab_name), + slice_as_string(&tab_name)); + if (err < 0) { + err = IO_ERROR; + goto exit; + } + free(slice_yield(&temp_tab_name)); + + err = write(lock_fd, table_list.buf, table_list.len); + if (err < 0) { + err = IO_ERROR; + goto exit; + } + err = close(lock_fd); + lock_fd = 0; + if (err < 0) { + unlink(slice_as_string(&tab_name)); + err = IO_ERROR; + goto exit; + } + + err = rename(slice_as_string(&lock_name), st->list_file); + if (err < 0) { + unlink(slice_as_string(&tab_name)); + err = IO_ERROR; + goto exit; + } + + err = stack_reload(st); +exit: + if (tab_fd > 0) { + close(tab_fd); + tab_fd = 0; + } + if (temp_tab_name.len > 0) { + unlink(slice_as_string(&temp_tab_name)); + } + unlink(slice_as_string(&lock_name)); + + if (lock_fd > 0) { + close(lock_fd); + lock_fd = 0; + } + + free(slice_yield(&lock_name)); + free(slice_yield(&temp_tab_name)); + free(slice_yield(&tab_name)); + free(slice_yield(&next_name)); + free(slice_yield(&table_list)); + writer_free(wr); + return err; +} + +uint64_t stack_next_update_index(struct stack *st) +{ + int sz = st->merged->stack_len; + if (sz > 0) { + return reader_max_update_index(st->merged->stack[sz - 1]) + 1; + } + return 1; +} + +static int stack_compact_locked(struct stack *st, int first, int last, + struct slice *temp_tab, + struct log_expiry_config *config) +{ + struct slice next_name = {}; + int tab_fd = -1; + struct writer *wr = NULL; + int err = 0; + + format_name(&next_name, + reader_min_update_index(st->merged->stack[first]), + reader_max_update_index(st->merged->stack[first])); + + slice_set_string(temp_tab, st->reftable_dir); + slice_append_string(temp_tab, "/"); + slice_append(temp_tab, next_name); + slice_append_string(temp_tab, ".temp.XXXXXX"); + + tab_fd = mkstemp((char *)slice_as_string(temp_tab)); + wr = new_writer(fd_writer, &tab_fd, &st->config); + + err = stack_write_compact(st, wr, first, last, config); + if (err < 0) { + goto exit; + } + err = writer_close(wr); + if (err < 0) { + goto exit; + } + writer_free(wr); + + err = close(tab_fd); + tab_fd = 0; + +exit: + if (tab_fd > 0) { + close(tab_fd); + tab_fd = 0; + } + if (err != 0 && temp_tab->len > 0) { + unlink(slice_as_string(temp_tab)); + free(slice_yield(temp_tab)); + } + free(slice_yield(&next_name)); + return err; +} + +int stack_write_compact(struct stack *st, struct writer *wr, int first, + int last, struct log_expiry_config *config) +{ + int subtabs_len = last - first + 1; + struct reader **subtabs = + calloc(sizeof(struct reader *), last - first + 1); + struct merged_table *mt = NULL; + int err = 0; + struct iterator it = {}; + struct ref_record ref = {}; + struct log_record log = {}; + + int i = 0, j = 0; + for (i = first, j = 0; i <= last; i++) { + struct reader *t = st->merged->stack[i]; + subtabs[j++] = t; + st->stats.bytes += t->size; + } + writer_set_limits(wr, st->merged->stack[first]->min_update_index, + st->merged->stack[last]->max_update_index); + + err = new_merged_table(&mt, subtabs, subtabs_len); + if (err < 0) { + free(subtabs); + goto exit; + } + + err = merged_table_seek_ref(mt, &it, ""); + if (err < 0) { + goto exit; + } + + while (true) { + err = iterator_next_ref(it, &ref); + if (err > 0) { + err = 0; + break; + } + if (err < 0) { + break; + } + if (first == 0 && ref_record_is_deletion(&ref)) { + continue; + } + + err = writer_add_ref(wr, &ref); + if (err < 0) { + break; + } + } + + err = merged_table_seek_log(mt, &it, ""); + if (err < 0) { + goto exit; + } + + while (true) { + err = iterator_next_log(it, &log); + if (err > 0) { + err = 0; + break; + } + if (err < 0) { + break; + } + if (first == 0 && log_record_is_deletion(&log)) { + continue; + } + + /* XXX collect stats? */ + + if (config != NULL && config->time > 0 && + log.time < config->time) { + continue; + } + + if (config != NULL && config->min_update_index > 0 && + log.update_index < config->min_update_index) { + continue; + } + + err = writer_add_log(wr, &log); + if (err < 0) { + break; + } + } + +exit: + iterator_destroy(&it); + if (mt != NULL) { + merged_table_clear(mt); + merged_table_free(mt); + } + ref_record_clear(&ref); + + return err; +} + +/* < 0: error. 0 == OK, > 0 attempt failed; could retry. */ +static int stack_compact_range(struct stack *st, int first, int last, + struct log_expiry_config *expiry) +{ + struct slice temp_tab_name = {}; + struct slice new_table_name = {}; + struct slice lock_file_name = {}; + struct slice ref_list_contents = {}; + struct slice new_table_path = {}; + int err = 0; + bool have_lock = false; + int lock_file_fd = 0; + int compact_count = last - first + 1; + char **delete_on_success = calloc(sizeof(char *), compact_count + 1); + char **subtable_locks = calloc(sizeof(char *), compact_count + 1); + int i = 0; + int j = 0; + + if (first > last || (expiry == NULL && first == last)) { + err = 0; + goto exit; + } + + st->stats.attempts++; + + slice_set_string(&lock_file_name, st->list_file); + slice_append_string(&lock_file_name, ".lock"); + + lock_file_fd = open(slice_as_string(&lock_file_name), + O_EXCL | O_CREAT | O_WRONLY, 0644); + if (lock_file_fd < 0) { + if (errno == EEXIST) { + err = 1; + } else { + err = IO_ERROR; + } + goto exit; + } + have_lock = true; + err = stack_uptodate(st); + if (err != 0) { + goto exit; + } + + for (i = first, j = 0; i <= last; i++) { + struct slice subtab_name = {}; + struct slice subtab_lock = {}; + slice_set_string(&subtab_name, st->reftable_dir); + slice_append_string(&subtab_name, "/"); + slice_append_string(&subtab_name, + reader_name(st->merged->stack[i])); + + slice_copy(&subtab_lock, subtab_name); + slice_append_string(&subtab_lock, ".lock"); + + { + int sublock_file_fd = + open(slice_as_string(&subtab_lock), + O_EXCL | O_CREAT | O_WRONLY, 0644); + if (sublock_file_fd > 0) { + close(sublock_file_fd); + } else if (sublock_file_fd < 0) { + if (errno == EEXIST) { + err = 1; + } + err = IO_ERROR; + } + } + + subtable_locks[j] = (char *)slice_as_string(&subtab_lock); + delete_on_success[j] = (char *)slice_as_string(&subtab_name); + j++; + + if (err != 0) { + goto exit; + } + } + + err = unlink(slice_as_string(&lock_file_name)); + if (err < 0) { + goto exit; + } + have_lock = false; + + err = stack_compact_locked(st, first, last, &temp_tab_name, expiry); + if (err < 0) { + goto exit; + } + + lock_file_fd = open(slice_as_string(&lock_file_name), + O_EXCL | O_CREAT | O_WRONLY, 0644); + if (lock_file_fd < 0) { + if (errno == EEXIST) { + err = 1; + } else { + err = IO_ERROR; + } + goto exit; + } + have_lock = true; + + format_name(&new_table_name, st->merged->stack[first]->min_update_index, + st->merged->stack[last]->max_update_index); + slice_append_string(&new_table_name, ".ref"); + + slice_set_string(&new_table_path, st->reftable_dir); + slice_append_string(&new_table_path, "/"); + + slice_append(&new_table_path, new_table_name); + + err = rename(slice_as_string(&temp_tab_name), + slice_as_string(&new_table_path)); + if (err < 0) { + goto exit; + } + + for (i = 0; i < first; i++) { + slice_append_string(&ref_list_contents, + st->merged->stack[i]->name); + slice_append_string(&ref_list_contents, "\n"); + } + slice_append(&ref_list_contents, new_table_name); + slice_append_string(&ref_list_contents, "\n"); + for (i = last + 1; i < st->merged->stack_len; i++) { + slice_append_string(&ref_list_contents, + st->merged->stack[i]->name); + slice_append_string(&ref_list_contents, "\n"); + } + + err = write(lock_file_fd, ref_list_contents.buf, ref_list_contents.len); + if (err < 0) { + unlink(slice_as_string(&new_table_path)); + goto exit; + } + err = close(lock_file_fd); + lock_file_fd = 0; + if (err < 0) { + unlink(slice_as_string(&new_table_path)); + goto exit; + } + + err = rename(slice_as_string(&lock_file_name), st->list_file); + if (err < 0) { + unlink(slice_as_string(&new_table_path)); + goto exit; + } + have_lock = false; + + for (char **p = delete_on_success; *p; p++) { + if (strcmp(*p, slice_as_string(&new_table_path))) { + unlink(*p); + } + } + + err = stack_reload_maybe_reuse(st, first < last); +exit: + for (char **p = subtable_locks; *p; p++) { + unlink(*p); + } + free_names(delete_on_success); + free_names(subtable_locks); + if (lock_file_fd > 0) { + close(lock_file_fd); + lock_file_fd = 0; + } + if (have_lock) { + unlink(slice_as_string(&lock_file_name)); + } + free(slice_yield(&new_table_name)); + free(slice_yield(&new_table_path)); + free(slice_yield(&ref_list_contents)); + free(slice_yield(&temp_tab_name)); + free(slice_yield(&lock_file_name)); + return err; +} + +int stack_compact_all(struct stack *st, struct log_expiry_config *config) +{ + return stack_compact_range(st, 0, st->merged->stack_len - 1, config); +} + +static int stack_compact_range_stats(struct stack *st, int first, int last, + struct log_expiry_config *config) +{ + int err = stack_compact_range(st, first, last, config); + if (err > 0) { + st->stats.failures++; + } + return err; +} + +static int segment_size(struct segment *s) +{ + return s->end - s->start; +} + +int fastlog2(uint64_t sz) +{ + int l = 0; + assert(sz > 0); + for (; sz; sz /= 2) { + l++; + } + return l - 1; +} + +struct segment *sizes_to_segments(int *seglen, uint64_t *sizes, int n) +{ + struct segment *segs = calloc(sizeof(struct segment), n); + int next = 0; + struct segment cur = {}; + int i = 0; + for (i = 0; i < n; i++) { + int log = fastlog2(sizes[i]); + if (cur.log != log && cur.bytes > 0) { + struct segment fresh = { + .start = i, + }; + + segs[next++] = cur; + cur = fresh; + } + + cur.log = log; + cur.end = i + 1; + cur.bytes += sizes[i]; + } + + segs[next++] = cur; + *seglen = next; + return segs; +} + +struct segment suggest_compaction_segment(uint64_t *sizes, int n) +{ + int seglen = 0; + struct segment *segs = sizes_to_segments(&seglen, sizes, n); + struct segment min_seg = { + .log = 64, + }; + int i = 0; + for (i = 0; i < seglen; i++) { + if (segment_size(&segs[i]) == 1) { + continue; + } + + if (segs[i].log < min_seg.log) { + min_seg = segs[i]; + } + } + + while (min_seg.start > 0) { + int prev = min_seg.start - 1; + if (fastlog2(min_seg.bytes) < fastlog2(sizes[prev])) { + break; + } + + min_seg.start = prev; + min_seg.bytes += sizes[prev]; + } + + free(segs); + return min_seg; +} + +static uint64_t *stack_table_sizes_for_compaction(struct stack *st) +{ + uint64_t *sizes = calloc(sizeof(uint64_t), st->merged->stack_len); + int i = 0; + for (i = 0; i < st->merged->stack_len; i++) { + /* overhead is 24 + 68 = 92. */ + sizes[i] = st->merged->stack[i]->size - 91; + } + return sizes; +} + +int stack_auto_compact(struct stack *st) +{ + uint64_t *sizes = stack_table_sizes_for_compaction(st); + struct segment seg = + suggest_compaction_segment(sizes, st->merged->stack_len); + free(sizes); + if (segment_size(&seg) > 0) { + return stack_compact_range_stats(st, seg.start, seg.end - 1, + NULL); + } + + return 0; +} + +struct compaction_stats *stack_compaction_stats(struct stack *st) +{ + return &st->stats; +} + +int stack_read_ref(struct stack *st, const char *refname, + struct ref_record *ref) +{ + struct iterator it = {}; + struct merged_table *mt = stack_merged_table(st); + int err = merged_table_seek_ref(mt, &it, refname); + if (err) { + goto exit; + } + + err = iterator_next_ref(it, ref); + if (err) { + goto exit; + } + + if (strcmp(ref->ref_name, refname) || ref_record_is_deletion(ref)) { + err = 1; + goto exit; + } + +exit: + iterator_destroy(&it); + return err; +} + +int stack_read_log(struct stack *st, const char *refname, + struct log_record *log) +{ + struct iterator it = {}; + struct merged_table *mt = stack_merged_table(st); + int err = merged_table_seek_log(mt, &it, refname); + if (err) { + goto exit; + } + + err = iterator_next_log(it, log); + if (err) { + goto exit; + } + + if (strcmp(log->ref_name, refname) || log_record_is_deletion(log)) { + err = 1; + goto exit; + } + +exit: + iterator_destroy(&it); + return err; +} diff --git a/reftable/stack.h b/reftable/stack.h new file mode 100644 index 0000000000..d5e2c93c29 --- /dev/null +++ b/reftable/stack.h @@ -0,0 +1,40 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef STACK_H +#define STACK_H + +#include "reftable.h" + +struct stack { + char *list_file; + char *reftable_dir; + + struct write_options config; + + struct merged_table *merged; + struct compaction_stats stats; +}; + +int read_lines(const char *filename, char ***lines); +int stack_try_add(struct stack *st, + int (*write_table)(struct writer *wr, void *arg), void *arg); +int stack_write_compact(struct stack *st, struct writer *wr, int first, + int last, struct log_expiry_config *config); +int fastlog2(uint64_t sz); + +struct segment { + int start, end; + int log; + uint64_t bytes; +}; + +struct segment *sizes_to_segments(int *seglen, uint64_t *sizes, int n); +struct segment suggest_compaction_segment(uint64_t *sizes, int n); + +#endif diff --git a/reftable/system.h b/reftable/system.h new file mode 100644 index 0000000000..ee7a6e1d70 --- /dev/null +++ b/reftable/system.h @@ -0,0 +1,55 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef SYSTEM_H +#define SYSTEM_H + +#include "config.h" + +#ifndef REFTABLE_STANDALONE + +#include "git-compat-util.h" +#include <zlib.h> + +#else + +#include <assert.h> +#include <errno.h> +#include <fcntl.h> +#include <inttypes.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/types.h> +#include <unistd.h> +#include <zlib.h> + +#define ARRAY_SIZE(a) sizeof((a)) / sizeof((a)[0]) +#define FREE_AND_NULL(x) \ + do { \ + free(x); \ + (x) = NULL; \ + } while (0) +#define QSORT(arr, n, cmp) qsort(arr, n, sizeof(arr[0]), cmp) +#define SWAP(a, b) \ + { \ + char tmp[sizeof(a)]; \ + assert(sizeof(a) == sizeof(b)); \ + memcpy(&tmp[0], &a, sizeof(a)); \ + memcpy(&a, &b, sizeof(a)); \ + memcpy(&b, &tmp[0], sizeof(a)); \ + } +#endif + +int uncompress_return_consumed(Bytef *dest, uLongf *destLen, + const Bytef *source, uLong *sourceLen); + +#endif diff --git a/reftable/tree.c b/reftable/tree.c new file mode 100644 index 0000000000..9bf7fe531f --- /dev/null +++ b/reftable/tree.c @@ -0,0 +1,66 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#include "tree.h" + +#include "system.h" + +struct tree_node *tree_search(void *key, struct tree_node **rootp, + int (*compare)(const void *, const void *), + int insert) +{ + if (*rootp == NULL) { + if (!insert) { + return NULL; + } else { + struct tree_node *n = + calloc(sizeof(struct tree_node), 1); + n->key = key; + *rootp = n; + return *rootp; + } + } + + { + int res = compare(key, (*rootp)->key); + if (res < 0) { + return tree_search(key, &(*rootp)->left, compare, + insert); + } else if (res > 0) { + return tree_search(key, &(*rootp)->right, compare, + insert); + } + } + return *rootp; +} + +void infix_walk(struct tree_node *t, void (*action)(void *arg, void *key), + void *arg) +{ + if (t->left != NULL) { + infix_walk(t->left, action, arg); + } + action(arg, t->key); + if (t->right != NULL) { + infix_walk(t->right, action, arg); + } +} + +void tree_free(struct tree_node *t) +{ + if (t == NULL) { + return; + } + if (t->left != NULL) { + tree_free(t->left); + } + if (t->right != NULL) { + tree_free(t->right); + } + free(t); +} diff --git a/reftable/tree.h b/reftable/tree.h new file mode 100644 index 0000000000..86a71715ae --- /dev/null +++ b/reftable/tree.h @@ -0,0 +1,24 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef TREE_H +#define TREE_H + +struct tree_node { + void *key; + struct tree_node *left, *right; +}; + +struct tree_node *tree_search(void *key, struct tree_node **rootp, + int (*compare)(const void *, const void *), + int insert); +void infix_walk(struct tree_node *t, void (*action)(void *arg, void *key), + void *arg); +void tree_free(struct tree_node *t); + +#endif diff --git a/reftable/writer.c b/reftable/writer.c new file mode 100644 index 0000000000..3247481df3 --- /dev/null +++ b/reftable/writer.c @@ -0,0 +1,623 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#include "writer.h" + +#include "system.h" + +#include "block.h" +#include "constants.h" +#include "record.h" +#include "reftable.h" +#include "tree.h" + +static struct block_stats *writer_block_stats(struct writer *w, byte typ) +{ + switch (typ) { + case 'r': + return &w->stats.ref_stats; + case 'o': + return &w->stats.obj_stats; + case 'i': + return &w->stats.idx_stats; + case 'g': + return &w->stats.log_stats; + } + assert(false); + return NULL; +} + +/* write data, queuing the padding for the next write. Returns negative for + * error. */ +static int padded_write(struct writer *w, byte *data, size_t len, int padding) +{ + int n = 0; + if (w->pending_padding > 0) { + byte *zeroed = calloc(w->pending_padding, 1); + int n = w->write(w->write_arg, zeroed, w->pending_padding); + if (n < 0) { + return n; + } + + w->pending_padding = 0; + free(zeroed); + } + + w->pending_padding = padding; + n = w->write(w->write_arg, data, len); + if (n < 0) { + return n; + } + n += padding; + return 0; +} + +static void options_set_defaults(struct write_options *opts) +{ + if (opts->restart_interval == 0) { + opts->restart_interval = 16; + } + + if (opts->block_size == 0) { + opts->block_size = DEFAULT_BLOCK_SIZE; + } +} + +static int writer_write_header(struct writer *w, byte *dest) +{ + memcpy((char *)dest, "REFT", 4); + dest[4] = 1; /* version */ + put_u24(dest + 5, w->opts.block_size); + put_u64(dest + 8, w->min_update_index); + put_u64(dest + 16, w->max_update_index); + return 24; +} + +static void writer_reinit_block_writer(struct writer *w, byte typ) +{ + int block_start = 0; + if (w->next == 0) { + block_start = HEADER_SIZE; + } + + block_writer_init(&w->block_writer_data, typ, w->block, + w->opts.block_size, block_start, w->hash_size); + w->block_writer = &w->block_writer_data; + w->block_writer->restart_interval = w->opts.restart_interval; +} + +struct writer *new_writer(int (*writer_func)(void *, byte *, int), + void *writer_arg, struct write_options *opts) +{ + struct writer *wp = calloc(sizeof(struct writer), 1); + options_set_defaults(opts); + if (opts->block_size >= (1 << 24)) { + /* TODO - error return? */ + abort(); + } + wp->hash_size = SHA1_SIZE; + wp->block = calloc(opts->block_size, 1); + wp->write = writer_func; + wp->write_arg = writer_arg; + wp->opts = *opts; + writer_reinit_block_writer(wp, BLOCK_TYPE_REF); + + return wp; +} + +void writer_set_limits(struct writer *w, uint64_t min, uint64_t max) +{ + w->min_update_index = min; + w->max_update_index = max; +} + +void writer_free(struct writer *w) +{ + free(w->block); + free(w); +} + +struct obj_index_tree_node { + struct slice hash; + uint64_t *offsets; + int offset_len; + int offset_cap; +}; + +static int obj_index_tree_node_compare(const void *a, const void *b) +{ + return slice_compare(((const struct obj_index_tree_node *)a)->hash, + ((const struct obj_index_tree_node *)b)->hash); +} + +static void writer_index_hash(struct writer *w, struct slice hash) +{ + uint64_t off = w->next; + + struct obj_index_tree_node want = { .hash = hash }; + + struct tree_node *node = tree_search(&want, &w->obj_index_tree, + &obj_index_tree_node_compare, 0); + struct obj_index_tree_node *key = NULL; + if (node == NULL) { + key = calloc(sizeof(struct obj_index_tree_node), 1); + slice_copy(&key->hash, hash); + tree_search((void *)key, &w->obj_index_tree, + &obj_index_tree_node_compare, 1); + } else { + key = node->key; + } + + if (key->offset_len > 0 && key->offsets[key->offset_len - 1] == off) { + return; + } + + if (key->offset_len == key->offset_cap) { + key->offset_cap = 2 * key->offset_cap + 1; + key->offsets = realloc(key->offsets, + sizeof(uint64_t) * key->offset_cap); + } + + key->offsets[key->offset_len++] = off; +} + +static int writer_add_record(struct writer *w, struct record rec) +{ + int result = -1; + struct slice key = {}; + int err = 0; + record_key(rec, &key); + if (slice_compare(w->last_key, key) >= 0) { + goto exit; + } + + slice_copy(&w->last_key, key); + if (w->block_writer == NULL) { + writer_reinit_block_writer(w, record_type(rec)); + } + + assert(block_writer_type(w->block_writer) == record_type(rec)); + + if (block_writer_add(w->block_writer, rec) == 0) { + result = 0; + goto exit; + } + + err = writer_flush_block(w); + if (err < 0) { + result = err; + goto exit; + } + + writer_reinit_block_writer(w, record_type(rec)); + err = block_writer_add(w->block_writer, rec); + if (err < 0) { + result = err; + goto exit; + } + + result = 0; +exit: + free(slice_yield(&key)); + return result; +} + +int writer_add_ref(struct writer *w, struct ref_record *ref) +{ + struct record rec = {}; + struct ref_record copy = *ref; + int err = 0; + + if (ref->ref_name == NULL) { + return API_ERROR; + } + if (ref->update_index < w->min_update_index || + ref->update_index > w->max_update_index) { + return API_ERROR; + } + + record_from_ref(&rec, ©); + copy.update_index -= w->min_update_index; + err = writer_add_record(w, rec); + if (err < 0) { + return err; + } + + if (!w->opts.skip_index_objects && ref->value != NULL) { + struct slice h = { + .buf = ref->value, + .len = w->hash_size, + }; + + writer_index_hash(w, h); + } + if (!w->opts.skip_index_objects && ref->target_value != NULL) { + struct slice h = { + .buf = ref->target_value, + .len = w->hash_size, + }; + writer_index_hash(w, h); + } + return 0; +} + +int writer_add_refs(struct writer *w, struct ref_record *refs, int n) +{ + int err = 0; + int i = 0; + QSORT(refs, n, ref_record_compare_name); + for (i = 0; err == 0 && i < n; i++) { + err = writer_add_ref(w, &refs[i]); + } + return err; +} + +int writer_add_log(struct writer *w, struct log_record *log) +{ + if (log->ref_name == NULL) { + return API_ERROR; + } + + if (w->block_writer != NULL && + block_writer_type(w->block_writer) == BLOCK_TYPE_REF) { + int err = writer_finish_public_section(w); + if (err < 0) { + return err; + } + } + + w->next -= w->pending_padding; + w->pending_padding = 0; + + { + struct record rec = {}; + int err; + record_from_log(&rec, log); + err = writer_add_record(w, rec); + return err; + } +} + +int writer_add_logs(struct writer *w, struct log_record *logs, int n) +{ + int err = 0; + int i = 0; + QSORT(logs, n, log_record_compare_key); + for (i = 0; err == 0 && i < n; i++) { + err = writer_add_log(w, &logs[i]); + } + return err; +} + +static int writer_finish_section(struct writer *w) +{ + byte typ = block_writer_type(w->block_writer); + uint64_t index_start = 0; + int max_level = 0; + int threshold = w->opts.unpadded ? 1 : 3; + int before_blocks = w->stats.idx_stats.blocks; + int err = writer_flush_block(w); + int i = 0; + if (err < 0) { + return err; + } + + while (w->index_len > threshold) { + struct index_record *idx = NULL; + int idx_len = 0; + + max_level++; + index_start = w->next; + writer_reinit_block_writer(w, BLOCK_TYPE_INDEX); + + idx = w->index; + idx_len = w->index_len; + + w->index = NULL; + w->index_len = 0; + w->index_cap = 0; + for (i = 0; i < idx_len; i++) { + struct record rec = {}; + record_from_index(&rec, idx + i); + if (block_writer_add(w->block_writer, rec) == 0) { + continue; + } + + { + int err = writer_flush_block(w); + if (err < 0) { + return err; + } + } + + writer_reinit_block_writer(w, BLOCK_TYPE_INDEX); + + err = block_writer_add(w->block_writer, rec); + assert(err == 0); + } + for (i = 0; i < idx_len; i++) { + free(slice_yield(&idx[i].last_key)); + } + free(idx); + } + + writer_clear_index(w); + + err = writer_flush_block(w); + if (err < 0) { + return err; + } + + { + struct block_stats *bstats = writer_block_stats(w, typ); + bstats->index_blocks = + w->stats.idx_stats.blocks - before_blocks; + bstats->index_offset = index_start; + bstats->max_index_level = max_level; + } + + /* Reinit lastKey, as the next section can start with any key. */ + w->last_key.len = 0; + + return 0; +} + +struct common_prefix_arg { + struct slice *last; + int max; +}; + +static void update_common(void *void_arg, void *key) +{ + struct common_prefix_arg *arg = (struct common_prefix_arg *)void_arg; + struct obj_index_tree_node *entry = (struct obj_index_tree_node *)key; + if (arg->last != NULL) { + int n = common_prefix_size(entry->hash, *arg->last); + if (n > arg->max) { + arg->max = n; + } + } + arg->last = &entry->hash; +} + +struct write_record_arg { + struct writer *w; + int err; +}; + +static void write_object_record(void *void_arg, void *key) +{ + struct write_record_arg *arg = (struct write_record_arg *)void_arg; + struct obj_index_tree_node *entry = (struct obj_index_tree_node *)key; + struct obj_record obj_rec = { + .hash_prefix = entry->hash.buf, + .hash_prefix_len = arg->w->stats.object_id_len, + .offsets = entry->offsets, + .offset_len = entry->offset_len, + }; + struct record rec = {}; + if (arg->err < 0) { + goto exit; + } + + record_from_obj(&rec, &obj_rec); + arg->err = block_writer_add(arg->w->block_writer, rec); + if (arg->err == 0) { + goto exit; + } + + arg->err = writer_flush_block(arg->w); + if (arg->err < 0) { + goto exit; + } + + writer_reinit_block_writer(arg->w, BLOCK_TYPE_OBJ); + arg->err = block_writer_add(arg->w->block_writer, rec); + if (arg->err == 0) { + goto exit; + } + obj_rec.offset_len = 0; + arg->err = block_writer_add(arg->w->block_writer, rec); + + /* Should be able to write into a fresh block. */ + assert(arg->err == 0); + +exit:; +} + +static void object_record_free(void *void_arg, void *key) +{ + struct obj_index_tree_node *entry = (struct obj_index_tree_node *)key; + + FREE_AND_NULL(entry->offsets); + free(slice_yield(&entry->hash)); + free(entry); +} + +static int writer_dump_object_index(struct writer *w) +{ + struct write_record_arg closure = { .w = w }; + struct common_prefix_arg common = {}; + if (w->obj_index_tree != NULL) { + infix_walk(w->obj_index_tree, &update_common, &common); + } + w->stats.object_id_len = common.max + 1; + + writer_reinit_block_writer(w, BLOCK_TYPE_OBJ); + + if (w->obj_index_tree != NULL) { + infix_walk(w->obj_index_tree, &write_object_record, &closure); + } + + if (closure.err < 0) { + return closure.err; + } + return writer_finish_section(w); +} + +int writer_finish_public_section(struct writer *w) +{ + byte typ = 0; + int err = 0; + + if (w->block_writer == NULL) { + return 0; + } + + typ = block_writer_type(w->block_writer); + err = writer_finish_section(w); + if (err < 0) { + return err; + } + if (typ == BLOCK_TYPE_REF && !w->opts.skip_index_objects && + w->stats.ref_stats.index_blocks > 0) { + err = writer_dump_object_index(w); + if (err < 0) { + return err; + } + } + + if (w->obj_index_tree != NULL) { + infix_walk(w->obj_index_tree, &object_record_free, NULL); + tree_free(w->obj_index_tree); + w->obj_index_tree = NULL; + } + + w->block_writer = NULL; + return 0; +} + +int writer_close(struct writer *w) +{ + byte footer[68]; + byte *p = footer; + + writer_finish_public_section(w); + + writer_write_header(w, footer); + p += 24; + put_u64(p, w->stats.ref_stats.index_offset); + p += 8; + put_u64(p, (w->stats.obj_stats.offset) << 5 | w->stats.object_id_len); + p += 8; + put_u64(p, w->stats.obj_stats.index_offset); + p += 8; + + put_u64(p, w->stats.log_stats.offset); + p += 8; + put_u64(p, w->stats.log_stats.index_offset); + p += 8; + + put_u32(p, crc32(0, footer, p - footer)); + p += 4; + w->pending_padding = 0; + + { + int n = padded_write(w, footer, sizeof(footer), 0); + if (n < 0) { + return n; + } + } + + /* free up memory. */ + block_writer_clear(&w->block_writer_data); + writer_clear_index(w); + free(slice_yield(&w->last_key)); + return 0; +} + +void writer_clear_index(struct writer *w) +{ + int i = 0; + for (i = 0; i < w->index_len; i++) { + free(slice_yield(&w->index[i].last_key)); + } + + FREE_AND_NULL(w->index); + w->index_len = 0; + w->index_cap = 0; +} + +const int debug = 0; + +static int writer_flush_nonempty_block(struct writer *w) +{ + byte typ = block_writer_type(w->block_writer); + struct block_stats *bstats = writer_block_stats(w, typ); + uint64_t block_typ_off = (bstats->blocks == 0) ? w->next : 0; + int raw_bytes = block_writer_finish(w->block_writer); + int padding = 0; + int err = 0; + if (raw_bytes < 0) { + return raw_bytes; + } + + if (!w->opts.unpadded && typ != BLOCK_TYPE_LOG) { + padding = w->opts.block_size - raw_bytes; + } + + if (block_typ_off > 0) { + bstats->offset = block_typ_off; + } + + bstats->entries += w->block_writer->entries; + bstats->restarts += w->block_writer->restart_len; + bstats->blocks++; + w->stats.blocks++; + + if (debug) { + fprintf(stderr, "block %c off %" PRIu64 " sz %d (%d)\n", typ, + w->next, raw_bytes, + get_u24(w->block + w->block_writer->header_off + 1)); + } + + if (w->next == 0) { + writer_write_header(w, w->block); + } + + err = padded_write(w, w->block, raw_bytes, padding); + if (err < 0) { + return err; + } + + if (w->index_cap == w->index_len) { + w->index_cap = 2 * w->index_cap + 1; + w->index = realloc(w->index, + sizeof(struct index_record) * w->index_cap); + } + + { + struct index_record ir = { + .offset = w->next, + }; + slice_copy(&ir.last_key, w->block_writer->last_key); + w->index[w->index_len] = ir; + } + + w->index_len++; + w->next += padding + raw_bytes; + block_writer_reset(&w->block_writer_data); + w->block_writer = NULL; + return 0; +} + +int writer_flush_block(struct writer *w) +{ + if (w->block_writer == NULL) { + return 0; + } + if (w->block_writer->entries == 0) { + return 0; + } + return writer_flush_nonempty_block(w); +} + +struct stats *writer_stats(struct writer *w) +{ + return &w->stats; +} diff --git a/reftable/writer.h b/reftable/writer.h new file mode 100644 index 0000000000..bd2386474b --- /dev/null +++ b/reftable/writer.h @@ -0,0 +1,46 @@ +/* +Copyright 2020 Google LLC + +Use of this source code is governed by a BSD-style +license that can be found in the LICENSE file or at +https://developers.google.com/open-source/licenses/bsd +*/ + +#ifndef WRITER_H +#define WRITER_H + +#include "basics.h" +#include "block.h" +#include "reftable.h" +#include "slice.h" +#include "tree.h" + +struct writer { + int (*write)(void *, byte *, int); + void *write_arg; + int pending_padding; + int hash_size; + struct slice last_key; + + uint64_t next; + uint64_t min_update_index, max_update_index; + struct write_options opts; + + byte *block; + struct block_writer *block_writer; + struct block_writer block_writer_data; + struct index_record *index; + int index_len; + int index_cap; + + /* tree for use with tsearch */ + struct tree_node *obj_index_tree; + + struct stats stats; +}; + +int writer_flush_block(struct writer *w); +void writer_clear_index(struct writer *w); +int writer_finish_public_section(struct writer *w); + +#endif diff --git a/reftable/zlib-compat.c b/reftable/zlib-compat.c new file mode 100644 index 0000000000..3e0b0f24f1 --- /dev/null +++ b/reftable/zlib-compat.c @@ -0,0 +1,92 @@ +/* taken from zlib's uncompr.c + + commit cacf7f1d4e3d44d871b605da3b647f07d718623f + Author: Mark Adler <madler@xxxxxxxxxxxxxxxxxx> + Date: Sun Jan 15 09:18:46 2017 -0800 + + zlib 1.2.11 + +*/ + +/* + * Copyright (C) 1995-2003, 2010, 2014, 2016 Jean-loup Gailly, Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +#include "system.h" + +/* clang-format off */ + +/* =========================================================================== + Decompresses the source buffer into the destination buffer. *sourceLen is + the byte length of the source buffer. Upon entry, *destLen is the total size + of the destination buffer, which must be large enough to hold the entire + uncompressed data. (The size of the uncompressed data must have been saved + previously by the compressor and transmitted to the decompressor by some + mechanism outside the scope of this compression library.) Upon exit, + *destLen is the size of the decompressed data and *sourceLen is the number + of source bytes consumed. Upon return, source + *sourceLen points to the + first unused input byte. + + uncompress returns Z_OK if success, Z_MEM_ERROR if there was not enough + memory, Z_BUF_ERROR if there was not enough room in the output buffer, or + Z_DATA_ERROR if the input data was corrupted, including if the input data is + an incomplete zlib stream. +*/ +int ZEXPORT uncompress_return_consumed ( + Bytef *dest, + uLongf *destLen, + const Bytef *source, + uLong *sourceLen) { + z_stream stream; + int err; + const uInt max = (uInt)-1; + uLong len, left; + Byte buf[1]; /* for detection of incomplete stream when *destLen == 0 */ + + len = *sourceLen; + if (*destLen) { + left = *destLen; + *destLen = 0; + } + else { + left = 1; + dest = buf; + } + + stream.next_in = (z_const Bytef *)source; + stream.avail_in = 0; + stream.zalloc = (alloc_func)0; + stream.zfree = (free_func)0; + stream.opaque = (voidpf)0; + + err = inflateInit(&stream); + if (err != Z_OK) return err; + + stream.next_out = dest; + stream.avail_out = 0; + + do { + if (stream.avail_out == 0) { + stream.avail_out = left > (uLong)max ? max : (uInt)left; + left -= stream.avail_out; + } + if (stream.avail_in == 0) { + stream.avail_in = len > (uLong)max ? max : (uInt)len; + len -= stream.avail_in; + } + err = inflate(&stream, Z_NO_FLUSH); + } while (err == Z_OK); + + *sourceLen -= len + stream.avail_in; + if (dest != buf) + *destLen = stream.total_out; + else if (stream.total_out && err == Z_BUF_ERROR) + left = 1; + + inflateEnd(&stream); + return err == Z_STREAM_END ? Z_OK : + err == Z_NEED_DICT ? Z_DATA_ERROR : + err == Z_BUF_ERROR && left + stream.avail_out ? Z_DATA_ERROR : + err; +} -- gitgitgadget
