Move index version 2 specific functions to their own file,
to prepare for the addition of a new index file format. With
the split into two files we have the non-index specific
functions in read-cache.c and the index-v2 specific functions
in read-cache-v2.c
Helped-by: Nguyen Thai Ngoc Duy <pclouds@xxxxxxxxx>
Signed-off-by: Thomas Gummerer <t.gummerer@xxxxxxxxx>
---
Makefile | 2 +
cache.h | 13 +-
read-cache-v2.c | 581 ++++++++++++++++++++++++++++++++++++++++++++++++
read-cache.c | 612 +++------------------------------------------------
read-cache.h | 57 +++++
test-index-version.c | 7 +-
6 files changed, 682 insertions(+), 590 deletions(-)
create mode 100644 read-cache-v2.c
create mode 100644 read-cache.h
diff --git a/Makefile b/Makefile
index 6b0c961..3ccd3a8 100644
--- a/Makefile
+++ b/Makefile
@@ -645,6 +645,7 @@ LIB_H += progress.h
LIB_H += prompt.h
LIB_H += quote.h
LIB_H += reachable.h
+LIB_H += read-cache.h
LIB_H += reflog-walk.h
LIB_H += refs.h
LIB_H += remote.h
@@ -768,6 +769,7 @@ LIB_OBJS += prompt.o
LIB_OBJS += quote.o
LIB_OBJS += reachable.o
LIB_OBJS += read-cache.o
+LIB_OBJS += read-cache-v2.o
LIB_OBJS += reflog-walk.o
LIB_OBJS += refs.o
LIB_OBJS += remote.o
diff --git a/cache.h b/cache.h
index 67f28b4..c77cdbe 100644
--- a/cache.h
+++ b/cache.h
@@ -94,16 +94,8 @@ unsigned long git_deflate_bound(git_zstream *, unsigned long);
*/
#define DEFAULT_GIT_PORT 9418
-/*
- * Basic data structures for the directory cache
- */
#define CACHE_SIGNATURE 0x44495243 /* "DIRC" */
-struct cache_header {
- unsigned int hdr_signature;
- unsigned int hdr_version;
- unsigned int hdr_entries;
-};
#define INDEX_FORMAT_LB 2
#define INDEX_FORMAT_UB 4
@@ -267,6 +259,7 @@ struct index_state {
unsigned name_hash_initialized : 1,
initialized : 1;
struct hash_table name_hash;
+ struct index_ops *ops;
};
extern struct index_state the_index;
@@ -471,8 +464,8 @@ extern int index_name_is_other(const struct index_state *, const char *, int);
#define CE_MATCH_RACY_IS_DIRTY 02
/* do stat comparison even if CE_SKIP_WORKTREE is true */
#define CE_MATCH_IGNORE_SKIP_WORKTREE 04
-extern int ie_match_stat(const struct index_state *, struct cache_entry *, struct stat *, unsigned int);
-extern int ie_modified(const struct index_state *, struct cache_entry *, struct stat *, unsigned int);
+extern int ie_match_stat(struct index_state *, struct cache_entry *, struct stat *, unsigned int);
+extern int ie_modified(struct index_state *, struct cache_entry *, struct stat *, unsigned int);
struct pathspec {
const char **raw; /* get_pathspec() result, not freed by free_pathspec() */
diff --git a/read-cache-v2.c b/read-cache-v2.c
new file mode 100644
index 0000000..2c5e78b
--- /dev/null
+++ b/read-cache-v2.c
@@ -0,0 +1,581 @@
+#include "cache.h"
+#include "read-cache.h"
+#include "resolve-undo.h"
+#include "cache-tree.h"
+#include "varint.h"
+
+/* Mask for the name length in ce_flags in the on-disk index */
+#define CE_NAMEMASK (0x0fff)
+
+struct cache_header {
+ unsigned int hdr_entries;
+};
+
+/*****************************************************************
+ * Index File I/O
+ *****************************************************************/
+
+/*
+ * dev/ino/uid/gid/size are also just tracked to the low 32 bits
+ * Again - this is just a (very strong in practice) heuristic that
+ * the inode hasn't changed.
+ *
+ * We save the fields in big-endian order to allow using the
+ * index file over NFS transparently.
+ */
+struct ondisk_cache_entry {
+ struct cache_time ctime;
+ struct cache_time mtime;
+ unsigned int dev;
+ unsigned int ino;
+ unsigned int mode;
+ unsigned int uid;
+ unsigned int gid;
+ unsigned int size;
+ unsigned char sha1[20];
+ unsigned short flags;
+ char name[FLEX_ARRAY]; /* more */
+};
+
+/*
+ * This struct is used when CE_EXTENDED bit is 1
+ * The struct must match ondisk_cache_entry exactly from
+ * ctime till flags
+ */
+struct ondisk_cache_entry_extended {
+ struct cache_time ctime;
+ struct cache_time mtime;
+ unsigned int dev;
+ unsigned int ino;
+ unsigned int mode;
+ unsigned int uid;
+ unsigned int gid;
+ unsigned int size;
+ unsigned char sha1[20];
+ unsigned short flags;
+ unsigned short flags2;
+ char name[FLEX_ARRAY]; /* more */
+};
+
+/* These are only used for v3 or lower */
+#define align_flex_name(STRUCT,len) ((offsetof(struct STRUCT,name) + (len) + 8) & ~7)
+#define ondisk_cache_entry_size(len) align_flex_name(ondisk_cache_entry,len)
+#define ondisk_cache_entry_extended_size(len) align_flex_name(ondisk_cache_entry_extended,len)
+#define ondisk_ce_size(ce) (((ce)->ce_flags & CE_EXTENDED) ? \
+ ondisk_cache_entry_extended_size(ce_namelen(ce)) : \
+ ondisk_cache_entry_size(ce_namelen(ce)))
+
+static int verify_hdr(void *mmap, unsigned long size)
+{
+ git_SHA_CTX c;
+ unsigned char sha1[20];
+
+ if (size < sizeof(struct cache_version_header)
+ + sizeof(struct cache_header) + 20)
+ die("index file smaller than expected");
+
+ git_SHA1_Init(&c);
+ git_SHA1_Update(&c, mmap, size - 20);
+ git_SHA1_Final(sha1, &c);
+ if (hashcmp(sha1, (unsigned char *)mmap + size - 20))
+ return error("bad index file sha1 signature");
+ return 0;
+}
+
+static int match_stat_basic(struct cache_entry *ce,
+ struct stat *st,
+ int changed)
+{
+ if (ce->ce_mtime.sec != (unsigned int)st->st_mtime)
+ changed |= MTIME_CHANGED;
+ if (trust_ctime && ce->ce_ctime.sec != (unsigned int)st->st_ctime)
+ changed |= CTIME_CHANGED;
+
+#ifdef USE_NSEC
+ if (ce->ce_mtime.nsec != ST_MTIME_NSEC(*st))
+ changed |= MTIME_CHANGED;
+ if (trust_ctime && ce->ce_ctime.nsec != ST_CTIME_NSEC(*st))
+ changed |= CTIME_CHANGED;
+#endif
+
+ if (ce->ce_uid != (unsigned int) st->st_uid ||
+ ce->ce_gid != (unsigned int) st->st_gid)
+ changed |= OWNER_CHANGED;
+ if (ce->ce_ino != (unsigned int) st->st_ino)
+ changed |= INODE_CHANGED;
+
+#ifdef USE_STDEV
+ /*
+ * st_dev breaks on network filesystems where different
+ * clients will have different views of what "device"
+ * the filesystem is on
+ */
+ if (ce->ce_dev != (unsigned int) st->st_dev)
+ changed |= INODE_CHANGED;
+#endif
+
+ if (ce->ce_size != (unsigned int) st->st_size)
+ changed |= DATA_CHANGED;
+
+ /* Racily smudged entry? */
+ if (!ce->ce_size) {
+ if (!is_empty_blob_sha1(ce->sha1))
+ changed |= DATA_CHANGED;
+ }
+
+ return changed;
+}
+
+static struct cache_entry *cache_entry_from_ondisk(struct ondisk_cache_entry *ondisk,
+ unsigned int flags,
+ const char *name,
+ size_t len)
+{
+ struct cache_entry *ce = xmalloc(cache_entry_size(len));
+
+ ce->ce_ctime.sec = ntoh_l(ondisk->ctime.sec);
+ ce->ce_mtime.sec = ntoh_l(ondisk->mtime.sec);
+ ce->ce_ctime.nsec = ntoh_l(ondisk->ctime.nsec);
+ ce->ce_mtime.nsec = ntoh_l(ondisk->mtime.nsec);
+ ce->ce_dev = ntoh_l(ondisk->dev);
+ ce->ce_ino = ntoh_l(ondisk->ino);
+ ce->ce_mode = ntoh_l(ondisk->mode);
+ ce->ce_uid = ntoh_l(ondisk->uid);
+ ce->ce_gid = ntoh_l(ondisk->gid);
+ ce->ce_size = ntoh_l(ondisk->size);
+ ce->ce_flags = flags & ~CE_NAMEMASK;
+ ce->ce_namelen = len;
+ hashcpy(ce->sha1, ondisk->sha1);
+ memcpy(ce->name, name, len);
+ ce->name[len] = '\0';
+ return ce;
+}
+
+/*
+ * Adjacent cache entries tend to share the leading paths, so it makes
+ * sense to only store the differences in later entries. In the v4
+ * on-disk format of the index, each on-disk cache entry stores the
+ * number of bytes to be stripped from the end of the previous name,
+ * and the bytes to append to the result, to come up with its name.
+ */
+static unsigned long expand_name_field(struct strbuf *name, const char *cp_)
+{
+ const unsigned char *ep, *cp = (const unsigned char *)cp_;
+ size_t len = decode_varint(&cp);
+
+ if (name->len < len)
+ die("malformed name field in the index");
+ strbuf_remove(name, name->len - len, len);
+ for (ep = cp; *ep; ep++)
+ ; /* find the end */
+ strbuf_add(name, cp, ep - cp);
+ return (const char *)ep + 1 - cp_;
+}
+
+static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk,
+ unsigned long *ent_size,
+ struct strbuf *previous_name)
+{
+ struct cache_entry *ce;
+ size_t len;
+ const char *name;
+ unsigned int flags;
+
+ /* On-disk flags are just 16 bits */
+ flags = ntoh_s(ondisk->flags);
+ len = flags & CE_NAMEMASK;
+
+ if (flags & CE_EXTENDED) {
+ struct ondisk_cache_entry_extended *ondisk2;
+ int extended_flags;
+ ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
+ extended_flags = ntoh_s(ondisk2->flags2) << 16;
+ /* We do not yet understand any bit out of CE_EXTENDED_FLAGS */
+ if (extended_flags & ~CE_EXTENDED_FLAGS)
+ die("Unknown index entry format %08x", extended_flags);
+ flags |= extended_flags;
+ name = ondisk2->name;
+ }
+ else
+ name = ondisk->name;
+
+ if (!previous_name) {
+ /* v3 and earlier */
+ if (len == CE_NAMEMASK)
+ len = strlen(name);
+ ce = cache_entry_from_ondisk(ondisk, flags, name, len);
+
+ *ent_size = ondisk_ce_size(ce);
+ } else {
+ unsigned long consumed;
+ consumed = expand_name_field(previous_name, name);
+ ce = cache_entry_from_ondisk(ondisk, flags,
+ previous_name->buf,
+ previous_name->len);
+
+ *ent_size = (name - ((char *)ondisk)) + consumed;
+ }
+ return ce;
+}
+
+static int read_index_extension(struct index_state *istate,
+ const char *ext, void *data, unsigned long sz)
+{
+ switch (CACHE_EXT(ext)) {
+ case CACHE_EXT_TREE:
+ istate->cache_tree = cache_tree_read(data, sz);
+ break;
+ case CACHE_EXT_RESOLVE_UNDO:
+ istate->resolve_undo = resolve_undo_read(data, sz);
+ break;
+ default:
+ if (*ext < 'A' || 'Z' < *ext)
+ return error("index uses %.4s extension, which we do not understand",
+ ext);
+ fprintf(stderr, "ignoring %.4s extension\n", ext);
+ break;
+ }
+ return 0;
+}
+
+static int read_index_v2(struct index_state *istate, void *mmap, int mmap_size)
+{
+ int i;
+ unsigned long src_offset;
+ struct cache_version_header *hdr;
+ struct cache_header *hdr_v2;
+ struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
+
+ hdr = mmap;
+ hdr_v2 = (struct cache_header *)((char *)mmap + sizeof(*hdr));
+ istate->version = ntohl(hdr->hdr_version);
+ istate->cache_nr = ntohl(hdr_v2->hdr_entries);
+ istate->cache_alloc = alloc_nr(istate->cache_nr);
+ istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
+ istate->initialized = 1;
+
+ if (istate->version == 4)
+ previous_name = &previous_name_buf;
+ else
+ previous_name = NULL;
+
+ src_offset = sizeof(*hdr) + sizeof(*hdr_v2);
+ for (i = 0; i < istate->cache_nr; i++) {
+ struct ondisk_cache_entry *disk_ce;
+ struct cache_entry *ce;
+ unsigned long consumed;
+
+ disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
+ ce = create_from_disk(disk_ce, &consumed, previous_name);
+ set_index_entry(istate, i, ce);
+
+ src_offset += consumed;
+ }
+ strbuf_release(&previous_name_buf);
+
+ while (src_offset <= mmap_size - 20 - 8) {
+ /* After an array of active_nr index entries,
+ * there can be arbitrary number of extended
+ * sections, each of which is prefixed with
+ * extension name (4-byte) and section length
+ * in 4-byte network byte order.
+ */
+ uint32_t extsize;
+ memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
+ extsize = ntohl(extsize);
+ if (read_index_extension(istate,
+ (const char *) mmap + src_offset,
+ (char *) mmap + src_offset + 8,
+ extsize) < 0)
+ goto unmap;
+ src_offset += 8;
+ src_offset += extsize;
+ }
+ return 0;
+unmap:
+ munmap(mmap, mmap_size);
+ die("index file corrupt");
+}
+
+#define WRITE_BUFFER_SIZE 8192
+static unsigned char write_buffer[WRITE_BUFFER_SIZE];
+static unsigned long write_buffer_len;
+
+static int ce_write_flush(git_SHA_CTX *context, int fd)
+{
+ unsigned int buffered = write_buffer_len;
+ if (buffered) {
+ git_SHA1_Update(context, write_buffer, buffered);
+ if (write_in_full(fd, write_buffer, buffered) != buffered)
+ return -1;
+ write_buffer_len = 0;
+ }
+ return 0;
+}
+
+static int ce_write(git_SHA_CTX *context, int fd, void *data, unsigned int len)
+{
+ while (len) {
+ unsigned int buffered = write_buffer_len;
+ unsigned int partial = WRITE_BUFFER_SIZE - buffered;
+ if (partial > len)
+ partial = len;
+ memcpy(write_buffer + buffered, data, partial);
+ buffered += partial;
+ if (buffered == WRITE_BUFFER_SIZE) {
+ write_buffer_len = buffered;
+ if (ce_write_flush(context, fd))
+ return -1;
+ buffered = 0;
+ }
+ write_buffer_len = buffered;
+ len -= partial;
+ data = (char *) data + partial;
+ }
+ return 0;
+}
+
+static int write_index_ext_header(git_SHA_CTX *context, int fd,
+ unsigned int ext, unsigned int sz)
+{
+ ext = htonl(ext);
+ sz = htonl(sz);
+ return ((ce_write(context, fd, &ext, 4) < 0) ||
+ (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
+}
+
+static int ce_flush(git_SHA_CTX *context, int fd)
+{
+ unsigned int left = write_buffer_len;
+
+ if (left) {
+ write_buffer_len = 0;
+ git_SHA1_Update(context, write_buffer, left);
+ }
+
+ /* Flush first if not enough space for SHA1 signature */
+ if (left + 20 > WRITE_BUFFER_SIZE) {
+ if (write_in_full(fd, write_buffer, left) != left)
+ return -1;
+ left = 0;
+ }
+
+ /* Append the SHA1 signature at the end */
+ git_SHA1_Final(write_buffer + left, context);
+ left += 20;
+ return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
+}
+
+static void ce_smudge_racily_clean_entry(struct index_state *istate, struct cache_entry *ce)
+{
+ /*
+ * The only thing we care about in this function is to smudge the
+ * falsely clean entry due to touch-update-touch race, so we leave
+ * everything else as they are. We are called for entries whose
+ * ce_mtime match the index file mtime.
+ *
+ * Note that this actually does not do much for gitlinks, for
+ * which ce_match_stat_basic() always goes to the actual
+ * contents. The caller checks with is_racy_timestamp() which
+ * always says "no" for gitlinks, so we are not called for them ;-)
+ */
+ struct stat st;
+
+ if (lstat(ce->name, &st) < 0)
+ return;
+ if (ce_match_stat_basic(istate, ce, &st))
+ return;
+ if (ce_modified_check_fs(ce, &st)) {
+ /* This is "racily clean"; smudge it. Note that this
+ * is a tricky code. At first glance, it may appear
+ * that it can break with this sequence:
+ *
+ * $ echo xyzzy >frotz
+ * $ git-update-index --add frotz
+ * $ : >frotz
+ * $ sleep 3
+ * $ echo filfre >nitfol
+ * $ git-update-index --add nitfol
+ *
+ * but it does not. When the second update-index runs,
+ * it notices that the entry "frotz" has the same timestamp
+ * as index, and if we were to smudge it by resetting its
+ * size to zero here, then the object name recorded
+ * in index is the 6-byte file but the cached stat information
+ * becomes zero --- which would then match what we would
+ * obtain from the filesystem next time we stat("frotz").
+ *
+ * However, the second update-index, before calling
+ * this function, notices that the cached size is 6
+ * bytes and what is on the filesystem is an empty
+ * file, and never calls us, so the cached size information
+ * for "frotz" stays 6 which does not match the filesystem.
+ */
+ ce->ce_size = 0;
+ }
+}
+
+/* Copy miscellaneous fields but not the name */
+static char *copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
+ struct cache_entry *ce)
+{
+ short flags;
+
+ ondisk->ctime.sec = htonl(ce->ce_ctime.sec);
+ ondisk->mtime.sec = htonl(ce->ce_mtime.sec);
+ ondisk->ctime.nsec = htonl(ce->ce_ctime.nsec);
+ ondisk->mtime.nsec = htonl(ce->ce_mtime.nsec);
+ ondisk->dev = htonl(ce->ce_dev);
+ ondisk->ino = htonl(ce->ce_ino);
+ ondisk->mode = htonl(ce->ce_mode);
+ ondisk->uid = htonl(ce->ce_uid);
+ ondisk->gid = htonl(ce->ce_gid);
+ ondisk->size = htonl(ce->ce_size);
+ hashcpy(ondisk->sha1, ce->sha1);
+
+ flags = ce->ce_flags;
+ flags |= (ce_namelen(ce) >= CE_NAMEMASK ? CE_NAMEMASK : ce_namelen(ce));
+ ondisk->flags = htons(flags);
+ if (ce->ce_flags & CE_EXTENDED) {
+ struct ondisk_cache_entry_extended *ondisk2;
+ ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
+ ondisk2->flags2 = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16);
+ return ondisk2->name;
+ }
+ else {
+ return ondisk->name;
+ }
+}
+
+static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce,
+ struct strbuf *previous_name)
+{
+ int size;
+ struct ondisk_cache_entry *ondisk;
+ char *name;
+ int result;
+
+ if (!previous_name) {
+ size = ondisk_ce_size(ce);
+ ondisk = xcalloc(1, size);
+ name = copy_cache_entry_to_ondisk(ondisk, ce);
+ memcpy(name, ce->name, ce_namelen(ce));
+ } else {
+ int common, to_remove, prefix_size;
+ unsigned char to_remove_vi[16];
+ for (common = 0;
+ (ce->name[common] &&
+ common < previous_name->len &&
+ ce->name[common] == previous_name->buf[common]);
+ common++)
+ ; /* still matching */
+ to_remove = previous_name->len - common;
+ prefix_size = encode_varint(to_remove, to_remove_vi);
+
+ if (ce->ce_flags & CE_EXTENDED)
+ size = offsetof(struct ondisk_cache_entry_extended, name);
+ else
+ size = offsetof(struct ondisk_cache_entry, name);
+ size += prefix_size + (ce_namelen(ce) - common + 1);
+
+ ondisk = xcalloc(1, size);
+ name = copy_cache_entry_to_ondisk(ondisk, ce);
+ memcpy(name, to_remove_vi, prefix_size);
+ memcpy(name + prefix_size, ce->name + common, ce_namelen(ce) - common);
+
+ strbuf_splice(previous_name, common, to_remove,
+ ce->name + common, ce_namelen(ce) - common);
+ }
+
+ result = ce_write(c, fd, ondisk, size);
+ free(ondisk);
+ return result;
+}
+
+static int write_index_v2(struct index_state *istate, int newfd)
+{
+ git_SHA_CTX c;
+ struct cache_version_header hdr;
+ struct cache_header hdr_v2;
+ int i, err, removed, extended, hdr_version;
+ struct cache_entry **cache = istate->cache;
+ int entries = istate->cache_nr;
+ struct stat st;
+ struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
+
+ for (i = removed = extended = 0; i < entries; i++) {
+ if (cache[i]->ce_flags & CE_REMOVE)
+ removed++;
+
+ /* reduce extended entries if possible */
+ cache[i]->ce_flags &= ~CE_EXTENDED;
+ if (cache[i]->ce_flags & CE_EXTENDED_FLAGS) {
+ extended++;
+ cache[i]->ce_flags |= CE_EXTENDED;
+ }
+ }
+
+ /* demote version 3 to version 2 when the latter suffices */
+ if (istate->version == 3 || istate->version == 2)
+ istate->version = extended ? 3 : 2;
+
+ hdr_version = istate->version;
+
+ hdr.hdr_signature = htonl(CACHE_SIGNATURE);
+ hdr.hdr_version = htonl(hdr_version);
+ hdr_v2.hdr_entries = htonl(entries - removed);
+
+ git_SHA1_Init(&c);
+ if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
+ return -1;
+ if (ce_write(&c, newfd, &hdr_v2, sizeof(hdr_v2)) < 0)
+ return -1;
+
+ previous_name = (hdr_version == 4) ? &previous_name_buf : NULL;
+ for (i = 0; i < entries; i++) {
+ struct cache_entry *ce = cache[i];
+ if (ce->ce_flags & CE_REMOVE)
+ continue;
+ if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
+ ce_smudge_racily_clean_entry(istate, ce);
+ if (ce_write_entry(&c, newfd, ce, previous_name) < 0)
+ return -1;
+ }
+ strbuf_release(&previous_name_buf);
+
+ /* Write extension data here */
+ if (istate->cache_tree) {
+ struct strbuf sb = STRBUF_INIT;
+
+ cache_tree_write(&sb, istate->cache_tree);
+ err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
+ || ce_write(&c, newfd, sb.buf, sb.len) < 0;
+ strbuf_release(&sb);
+ if (err)
+ return -1;
+ }
+ if (istate->resolve_undo) {
+ struct strbuf sb = STRBUF_INIT;
+
+ resolve_undo_write(&sb, istate->resolve_undo);
+ err = write_index_ext_header(&c, newfd, CACHE_EXT_RESOLVE_UNDO,
+ sb.len) < 0
+ || ce_write(&c, newfd, sb.buf, sb.len) < 0;
+ strbuf_release(&sb);
+ if (err)
+ return -1;
+ }
+
+ if (ce_flush(&c, newfd) || fstat(newfd, &st))
+ return -1;
+ istate->timestamp.sec = (unsigned int)st.st_mtime;
+ istate->timestamp.nsec = ST_MTIME_NSEC(st);
+ return 0;
+}
+
+struct index_ops v2_ops = {
+ match_stat_basic,
+ verify_hdr,
+ read_index_v2,
+ write_index_v2
+};
diff --git a/read-cache.c b/read-cache.c
index 2f8159f..6a8b4b1 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -5,6 +5,7 @@
*/
#define NO_THE_INDEX_COMPATIBILITY_MACROS
#include "cache.h"
+#include "read-cache.h"
#include "cache-tree.h"
#include "refs.h"
#include "dir.h"
@@ -17,26 +18,9 @@
static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really);
-/* Mask for the name length in ce_flags in the on-disk index */
-
-#define CE_NAMEMASK (0x0fff)
-
-/* Index extensions.
- *
- * The first letter should be 'A'..'Z' for extensions that are not
- * necessary for a correct operation (i.e. optimization data).
- * When new extensions are added that _needs_ to be understood in
- * order to correctly interpret the index file, pick character that
- * is outside the range, to cause the reader to abort.
- */
-
-#define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
-#define CACHE_EXT_TREE 0x54524545 /* "TREE" */
-#define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */
-
struct index_state the_index;
-static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
+void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
{
istate->cache[nr] = ce;
add_name_hash(istate, ce);
@@ -143,7 +127,7 @@ static int ce_compare_gitlink(struct cache_entry *ce)
return hashcmp(sha1, ce->sha1);
}
-static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
+int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
{
switch (st->st_mode & S_IFMT) {
case S_IFREG:
@@ -163,7 +147,17 @@ static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
return 0;
}
-static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
+static void check_set_istate_ops(struct index_state *istate)
+{
+ if (!istate->version)
+ istate->version = INDEX_FORMAT_DEFAULT;
+ if (!istate->ops)
+ if (istate->version >= 2 && istate->version <=4)
+ istate->ops = &v2_ops;
+}
+
+int ce_match_stat_basic(struct index_state *istate,
+ struct cache_entry *ce, struct stat *st)
{
unsigned int changed = 0;
@@ -195,47 +189,13 @@ static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
default:
die("internal error: ce_mode is %o", ce->ce_mode);
}
- if (ce->ce_mtime.sec != (unsigned int)st->st_mtime)
- changed |= MTIME_CHANGED;
- if (trust_ctime && ce->ce_ctime.sec != (unsigned int)st->st_ctime)
- changed |= CTIME_CHANGED;
-
-#ifdef USE_NSEC
- if (ce->ce_mtime.nsec != ST_MTIME_NSEC(*st))
- changed |= MTIME_CHANGED;
- if (trust_ctime && ce->ce_ctime.nsec != ST_CTIME_NSEC(*st))
- changed |= CTIME_CHANGED;
-#endif
-
- if (ce->ce_uid != (unsigned int) st->st_uid ||
- ce->ce_gid != (unsigned int) st->st_gid)
- changed |= OWNER_CHANGED;
- if (ce->ce_ino != (unsigned int) st->st_ino)
- changed |= INODE_CHANGED;
-
-#ifdef USE_STDEV
- /*
- * st_dev breaks on network filesystems where different
- * clients will have different views of what "device"
- * the filesystem is on
- */
- if (ce->ce_dev != (unsigned int) st->st_dev)
- changed |= INODE_CHANGED;
-#endif
-
- if (ce->ce_size != (unsigned int) st->st_size)
- changed |= DATA_CHANGED;
-
- /* Racily smudged entry? */
- if (!ce->ce_size) {
- if (!is_empty_blob_sha1(ce->sha1))
- changed |= DATA_CHANGED;
- }
+ check_set_istate_ops(istate);
+ changed = istate->ops->match_stat_basic(ce, st, changed);
return changed;
}
-static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce)
+int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce)
{
return (!S_ISGITLINK(ce->ce_mode) &&
istate->timestamp.sec &&
@@ -250,7 +210,7 @@ static int is_racy_timestamp(const struct index_state *istate, struct cache_entr
);
}
-int ie_match_stat(const struct index_state *istate,
+int ie_match_stat(struct index_state *istate,
struct cache_entry *ce, struct stat *st,
unsigned int options)
{
@@ -278,7 +238,7 @@ int ie_match_stat(const struct index_state *istate,
if (ce->ce_flags & CE_INTENT_TO_ADD)
return DATA_CHANGED | TYPE_CHANGED | MODE_CHANGED;
- changed = ce_match_stat_basic(ce, st);
+ changed = ce_match_stat_basic(istate, ce, st);
/*
* Within 1 second of this sequence:
@@ -306,7 +266,7 @@ int ie_match_stat(const struct index_state *istate,
return changed;
}
-int ie_modified(const struct index_state *istate,
+int ie_modified(struct index_state *istate,
struct cache_entry *ce, struct stat *st, unsigned int options)
{
int changed, changed_fs;
@@ -1190,99 +1150,18 @@ static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int reall
return refresh_cache_ent(&the_index, ce, really, NULL, NULL);
}
-
-/*****************************************************************
- * Index File I/O
- *****************************************************************/
-
-#define INDEX_FORMAT_DEFAULT 3
-
-/*
- * dev/ino/uid/gid/size are also just tracked to the low 32 bits
- * Again - this is just a (very strong in practice) heuristic that
- * the inode hasn't changed.
- *
- * We save the fields in big-endian order to allow using the
- * index file over NFS transparently.
- */
-struct ondisk_cache_entry {
- struct cache_time ctime;
- struct cache_time mtime;
- unsigned int dev;
- unsigned int ino;
- unsigned int mode;
- unsigned int uid;
- unsigned int gid;
- unsigned int size;
- unsigned char sha1[20];
- unsigned short flags;
- char name[FLEX_ARRAY]; /* more */
-};
-
-/*
- * This struct is used when CE_EXTENDED bit is 1
- * The struct must match ondisk_cache_entry exactly from
- * ctime till flags
- */
-struct ondisk_cache_entry_extended {
- struct cache_time ctime;
- struct cache_time mtime;
- unsigned int dev;
- unsigned int ino;
- unsigned int mode;
- unsigned int uid;
- unsigned int gid;
- unsigned int size;
- unsigned char sha1[20];
- unsigned short flags;
- unsigned short flags2;
- char name[FLEX_ARRAY]; /* more */
-};
-
-/* These are only used for v3 or lower */
-#define align_flex_name(STRUCT,len) ((offsetof(struct STRUCT,name) + (len) + 8) & ~7)
-#define ondisk_cache_entry_size(len) align_flex_name(ondisk_cache_entry,len)
-#define ondisk_cache_entry_extended_size(len) align_flex_name(ondisk_cache_entry_extended,len)
-#define ondisk_ce_size(ce) (((ce)->ce_flags & CE_EXTENDED) ? \
- ondisk_cache_entry_extended_size(ce_namelen(ce)) : \
- ondisk_cache_entry_size(ce_namelen(ce)))
-
-static int verify_hdr(struct cache_header *hdr, unsigned long size)
+static int verify_hdr_version(struct index_state *istate,
+ struct cache_version_header *hdr, unsigned long size)
{
- git_SHA_CTX c;
- unsigned char sha1[20];
int hdr_version;
if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
return error("bad signature");
hdr_version = ntohl(hdr->hdr_version);
- if (hdr_version < 2 || 4 < hdr_version)
+ if (hdr_version >= 2 && hdr_version <= 4)
+ istate->ops = &v2_ops;
+ else
return error("bad index version %d", hdr_version);
- git_SHA1_Init(&c);
- git_SHA1_Update(&c, hdr, size - 20);
- git_SHA1_Final(sha1, &c);
- if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
- return error("bad index file sha1 signature");
- return 0;
-}
-
-static int read_index_extension(struct index_state *istate,
- const char *ext, void *data, unsigned long sz)
-{
- switch (CACHE_EXT(ext)) {
- case CACHE_EXT_TREE:
- istate->cache_tree = cache_tree_read(data, sz);
- break;
- case CACHE_EXT_RESOLVE_UNDO:
- istate->resolve_undo = resolve_undo_read(data, sz);
- break;
- default:
- if (*ext < 'A' || 'Z' < *ext)
- return error("index uses %.4s extension, which we do not understand",
- ext);
- fprintf(stderr, "ignoring %.4s extension\n", ext);
- break;
- }
return 0;
}
@@ -1291,128 +1170,14 @@ int read_index(struct index_state *istate)
return read_index_from(istate, get_index_file());
}
-#ifndef NEEDS_ALIGNED_ACCESS
-#define ntoh_s(var) ntohs(var)
-#define ntoh_l(var) ntohl(var)
-#else
-static inline uint16_t ntoh_s_force_align(void *p)
-{
- uint16_t x;
- memcpy(&x, p, sizeof(x));
- return ntohs(x);
-}
-static inline uint32_t ntoh_l_force_align(void *p)
-{
- uint32_t x;
- memcpy(&x, p, sizeof(x));
- return ntohl(x);
-}
-#define ntoh_s(var) ntoh_s_force_align(&(var))
-#define ntoh_l(var) ntoh_l_force_align(&(var))
-#endif
-
-static struct cache_entry *cache_entry_from_ondisk(struct ondisk_cache_entry *ondisk,
- unsigned int flags,
- const char *name,
- size_t len)
-{
- struct cache_entry *ce = xmalloc(cache_entry_size(len));
-
- ce->ce_ctime.sec = ntoh_l(ondisk->ctime.sec);
- ce->ce_mtime.sec = ntoh_l(ondisk->mtime.sec);
- ce->ce_ctime.nsec = ntoh_l(ondisk->ctime.nsec);
- ce->ce_mtime.nsec = ntoh_l(ondisk->mtime.nsec);
- ce->ce_dev = ntoh_l(ondisk->dev);
- ce->ce_ino = ntoh_l(ondisk->ino);
- ce->ce_mode = ntoh_l(ondisk->mode);
- ce->ce_uid = ntoh_l(ondisk->uid);
- ce->ce_gid = ntoh_l(ondisk->gid);
- ce->ce_size = ntoh_l(ondisk->size);
- ce->ce_flags = flags & ~CE_NAMEMASK;
- ce->ce_namelen = len;
- hashcpy(ce->sha1, ondisk->sha1);
- memcpy(ce->name, name, len);
- ce->name[len] = '\0';
- return ce;
-}
-
-/*
- * Adjacent cache entries tend to share the leading paths, so it makes
- * sense to only store the differences in later entries. In the v4
- * on-disk format of the index, each on-disk cache entry stores the
- * number of bytes to be stripped from the end of the previous name,
- * and the bytes to append to the result, to come up with its name.
- */
-static unsigned long expand_name_field(struct strbuf *name, const char *cp_)
-{
- const unsigned char *ep, *cp = (const unsigned char *)cp_;
- size_t len = decode_varint(&cp);
-
- if (name->len < len)
- die("malformed name field in the index");
- strbuf_remove(name, name->len - len, len);
- for (ep = cp; *ep; ep++)
- ; /* find the end */
- strbuf_add(name, cp, ep - cp);
- return (const char *)ep + 1 - cp_;
-}
-
-static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk,
- unsigned long *ent_size,
- struct strbuf *previous_name)
-{
- struct cache_entry *ce;
- size_t len;
- const char *name;
- unsigned int flags;
-
- /* On-disk flags are just 16 bits */
- flags = ntoh_s(ondisk->flags);
- len = flags & CE_NAMEMASK;
-
- if (flags & CE_EXTENDED) {
- struct ondisk_cache_entry_extended *ondisk2;
- int extended_flags;
- ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
- extended_flags = ntoh_s(ondisk2->flags2) << 16;
- /* We do not yet understand any bit out of CE_EXTENDED_FLAGS */
- if (extended_flags & ~CE_EXTENDED_FLAGS)
- die("Unknown index entry format %08x", extended_flags);
- flags |= extended_flags;
- name = ondisk2->name;
- }
- else
- name = ondisk->name;
-
- if (!previous_name) {
- /* v3 and earlier */
- if (len == CE_NAMEMASK)
- len = strlen(name);
- ce = cache_entry_from_ondisk(ondisk, flags, name, len);
-
- *ent_size = ondisk_ce_size(ce);
- } else {
- unsigned long consumed;
- consumed = expand_name_field(previous_name, name);
- ce = cache_entry_from_ondisk(ondisk, flags,
- previous_name->buf,
- previous_name->len);
-
- *ent_size = (name - ((char *)ondisk)) + consumed;
- }
- return ce;
-}
-
/* remember to discard_cache() before reading a different cache! */
int read_index_from(struct index_state *istate, const char *path)
{
- int fd, i;
+ int fd;
struct stat st;
- unsigned long src_offset;
- struct cache_header *hdr;
+ struct cache_version_header *hdr;
void *mmap;
size_t mmap_size;
- struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
errno = EBUSY;
if (istate->initialized)
@@ -1433,69 +1198,27 @@ int read_index_from(struct index_state *istate, const char *path)
errno = EINVAL;
mmap_size = xsize_t(st.st_size);
- if (mmap_size < sizeof(struct cache_header) + 20)
- die("index file smaller than expected");
-
mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
close(fd);
if (mmap == MAP_FAILED)
die_errno("unable to map index file");
hdr = mmap;
- if (verify_hdr(hdr, mmap_size) < 0)
+ if (verify_hdr_version(istate, hdr, mmap_size) < 0)
goto unmap;
- istate->version = ntohl(hdr->hdr_version);
- istate->cache_nr = ntohl(hdr->hdr_entries);
- istate->cache_alloc = alloc_nr(istate->cache_nr);
- istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
- istate->initialized = 1;
-
- if (istate->version == 4)
- previous_name = &previous_name_buf;
- else
- previous_name = NULL;
-
- src_offset = sizeof(*hdr);
- for (i = 0; i < istate->cache_nr; i++) {
- struct ondisk_cache_entry *disk_ce;
- struct cache_entry *ce;
- unsigned long consumed;
-
- disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
- ce = create_from_disk(disk_ce, &consumed, previous_name);
- set_index_entry(istate, i, ce);
+ if (istate->ops->verify_hdr(mmap, mmap_size) < 0)
+ goto unmap;
- src_offset += consumed;
- }
- strbuf_release(&previous_name_buf);
+ istate->ops->read_index(istate, mmap, mmap_size);
istate->timestamp.sec = st.st_mtime;
istate->timestamp.nsec = ST_MTIME_NSEC(st);
- while (src_offset <= mmap_size - 20 - 8) {
- /* After an array of active_nr index entries,
- * there can be arbitrary number of extended
- * sections, each of which is prefixed with
- * extension name (4-byte) and section length
- * in 4-byte network byte order.
- */
- uint32_t extsize;
- memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
- extsize = ntohl(extsize);
- if (read_index_extension(istate,
- (const char *) mmap + src_offset,
- (char *) mmap + src_offset + 8,
- extsize) < 0)
- goto unmap;
- src_offset += 8;
- src_offset += extsize;
- }
munmap(mmap, mmap_size);
return istate->cache_nr;
unmap:
munmap(mmap, mmap_size);
- errno = EINVAL;
die("index file corrupt");
}
@@ -1534,201 +1257,6 @@ int unmerged_index(const struct index_state *istate)
return 0;
}
-#define WRITE_BUFFER_SIZE 8192
-static unsigned char write_buffer[WRITE_BUFFER_SIZE];
-static unsigned long write_buffer_len;
-
-static int ce_write_flush(git_SHA_CTX *context, int fd)
-{
- unsigned int buffered = write_buffer_len;
- if (buffered) {
- git_SHA1_Update(context, write_buffer, buffered);
- if (write_in_full(fd, write_buffer, buffered) != buffered)
- return -1;
- write_buffer_len = 0;
- }
- return 0;
-}
-
-static int ce_write(git_SHA_CTX *context, int fd, void *data, unsigned int len)
-{
- while (len) {
- unsigned int buffered = write_buffer_len;
- unsigned int partial = WRITE_BUFFER_SIZE - buffered;
- if (partial > len)
- partial = len;
- memcpy(write_buffer + buffered, data, partial);
- buffered += partial;
- if (buffered == WRITE_BUFFER_SIZE) {
- write_buffer_len = buffered;
- if (ce_write_flush(context, fd))
- return -1;
- buffered = 0;
- }
- write_buffer_len = buffered;
- len -= partial;
- data = (char *) data + partial;
- }
- return 0;
-}
-
-static int write_index_ext_header(git_SHA_CTX *context, int fd,
- unsigned int ext, unsigned int sz)
-{
- ext = htonl(ext);
- sz = htonl(sz);
- return ((ce_write(context, fd, &ext, 4) < 0) ||
- (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
-}
-
-static int ce_flush(git_SHA_CTX *context, int fd)
-{
- unsigned int left = write_buffer_len;
-
- if (left) {
- write_buffer_len = 0;
- git_SHA1_Update(context, write_buffer, left);
- }
-
- /* Flush first if not enough space for SHA1 signature */
- if (left + 20 > WRITE_BUFFER_SIZE) {
- if (write_in_full(fd, write_buffer, left) != left)
- return -1;
- left = 0;
- }
-
- /* Append the SHA1 signature at the end */
- git_SHA1_Final(write_buffer + left, context);
- left += 20;
- return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
-}
-
-static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
-{
- /*
- * The only thing we care about in this function is to smudge the
- * falsely clean entry due to touch-update-touch race, so we leave
- * everything else as they are. We are called for entries whose
- * ce_mtime match the index file mtime.
- *
- * Note that this actually does not do much for gitlinks, for
- * which ce_match_stat_basic() always goes to the actual
- * contents. The caller checks with is_racy_timestamp() which
- * always says "no" for gitlinks, so we are not called for them ;-)
- */
- struct stat st;
-
- if (lstat(ce->name, &st) < 0)
- return;
- if (ce_match_stat_basic(ce, &st))
- return;
- if (ce_modified_check_fs(ce, &st)) {
- /* This is "racily clean"; smudge it. Note that this
- * is a tricky code. At first glance, it may appear
- * that it can break with this sequence:
- *
- * $ echo xyzzy >frotz
- * $ git-update-index --add frotz
- * $ : >frotz
- * $ sleep 3
- * $ echo filfre >nitfol
- * $ git-update-index --add nitfol
- *
- * but it does not. When the second update-index runs,
- * it notices that the entry "frotz" has the same timestamp
- * as index, and if we were to smudge it by resetting its
- * size to zero here, then the object name recorded
- * in index is the 6-byte file but the cached stat information
- * becomes zero --- which would then match what we would
- * obtain from the filesystem next time we stat("frotz").
- *
- * However, the second update-index, before calling
- * this function, notices that the cached size is 6
- * bytes and what is on the filesystem is an empty
- * file, and never calls us, so the cached size information
- * for "frotz" stays 6 which does not match the filesystem.
- */
- ce->ce_size = 0;
- }
-}
-
-/* Copy miscellaneous fields but not the name */
-static char *copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
- struct cache_entry *ce)
-{
- short flags;
-
- ondisk->ctime.sec = htonl(ce->ce_ctime.sec);
- ondisk->mtime.sec = htonl(ce->ce_mtime.sec);
- ondisk->ctime.nsec = htonl(ce->ce_ctime.nsec);
- ondisk->mtime.nsec = htonl(ce->ce_mtime.nsec);
- ondisk->dev = htonl(ce->ce_dev);
- ondisk->ino = htonl(ce->ce_ino);
- ondisk->mode = htonl(ce->ce_mode);
- ondisk->uid = htonl(ce->ce_uid);
- ondisk->gid = htonl(ce->ce_gid);
- ondisk->size = htonl(ce->ce_size);
- hashcpy(ondisk->sha1, ce->sha1);
-
- flags = ce->ce_flags;
- flags |= (ce_namelen(ce) >= CE_NAMEMASK ? CE_NAMEMASK : ce_namelen(ce));
- ondisk->flags = htons(flags);
- if (ce->ce_flags & CE_EXTENDED) {
- struct ondisk_cache_entry_extended *ondisk2;
- ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
- ondisk2->flags2 = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16);
- return ondisk2->name;
- }
- else {
- return ondisk->name;
- }
-}
-
-static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce,
- struct strbuf *previous_name)
-{
- int size;
- struct ondisk_cache_entry *ondisk;
- char *name;
- int result;
-
- if (!previous_name) {
- size = ondisk_ce_size(ce);
- ondisk = xcalloc(1, size);
- name = copy_cache_entry_to_ondisk(ondisk, ce);
- memcpy(name, ce->name, ce_namelen(ce));
- } else {
- int common, to_remove, prefix_size;
- unsigned char to_remove_vi[16];
- for (common = 0;
- (ce->name[common] &&
- common < previous_name->len &&
- ce->name[common] == previous_name->buf[common]);
- common++)
- ; /* still matching */
- to_remove = previous_name->len - common;
- prefix_size = encode_varint(to_remove, to_remove_vi);
-
- if (ce->ce_flags & CE_EXTENDED)
- size = offsetof(struct ondisk_cache_entry_extended, name);
- else
- size = offsetof(struct ondisk_cache_entry, name);
- size += prefix_size + (ce_namelen(ce) - common + 1);
-
- ondisk = xcalloc(1, size);
- name = copy_cache_entry_to_ondisk(ondisk, ce);
- memcpy(name, to_remove_vi, prefix_size);
- memcpy(name + prefix_size, ce->name + common, ce_namelen(ce) - common);
-
- strbuf_splice(previous_name, common, to_remove,
- ce->name + common, ce_namelen(ce) - common);
- }
-
- result = ce_write(c, fd, ondisk, size);
- free(ondisk);
- return result;
-}
-
static int has_racy_timestamp(struct index_state *istate)
{
int entries = istate->cache_nr;
@@ -1756,83 +1284,9 @@ void update_index_if_able(struct index_state *istate, struct lock_file *lockfile
int write_index(struct index_state *istate, int newfd)
{
- git_SHA_CTX c;
- struct cache_header hdr;
- int i, err, removed, extended, hdr_version;
- struct cache_entry **cache = istate->cache;
- int entries = istate->cache_nr;
- struct stat st;
- struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
-
- for (i = removed = extended = 0; i < entries; i++) {
- if (cache[i]->ce_flags & CE_REMOVE)
- removed++;
-
- /* reduce extended entries if possible */
- cache[i]->ce_flags &= ~CE_EXTENDED;
- if (cache[i]->ce_flags & CE_EXTENDED_FLAGS) {
- extended++;
- cache[i]->ce_flags |= CE_EXTENDED;
- }
- }
-
- if (!istate->version)
- istate->version = INDEX_FORMAT_DEFAULT;
-
- /* demote version 3 to version 2 when the latter suffices */
- if (istate->version == 3 || istate->version == 2)
- istate->version = extended ? 3 : 2;
-
- hdr_version = istate->version;
-
- hdr.hdr_signature = htonl(CACHE_SIGNATURE);
- hdr.hdr_version = htonl(hdr_version);
- hdr.hdr_entries = htonl(entries - removed);
-
- git_SHA1_Init(&c);
- if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
- return -1;
-
- previous_name = (hdr_version == 4) ? &previous_name_buf : NULL;
- for (i = 0; i < entries; i++) {
- struct cache_entry *ce = cache[i];
- if (ce->ce_flags & CE_REMOVE)
- continue;
- if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
- ce_smudge_racily_clean_entry(ce);
- if (ce_write_entry(&c, newfd, ce, previous_name) < 0)
- return -1;
- }
- strbuf_release(&previous_name_buf);
+ check_set_istate_ops(istate);
- /* Write extension data here */
- if (istate->cache_tree) {
- struct strbuf sb = STRBUF_INIT;
-
- cache_tree_write(&sb, istate->cache_tree);
- err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
- || ce_write(&c, newfd, sb.buf, sb.len) < 0;
- strbuf_release(&sb);
- if (err)
- return -1;
- }
- if (istate->resolve_undo) {
- struct strbuf sb = STRBUF_INIT;
-
- resolve_undo_write(&sb, istate->resolve_undo);
- err = write_index_ext_header(&c, newfd, CACHE_EXT_RESOLVE_UNDO,
- sb.len) < 0
- || ce_write(&c, newfd, sb.buf, sb.len) < 0;
- strbuf_release(&sb);
- if (err)
- return -1;
- }
-
- if (ce_flush(&c, newfd) || fstat(newfd, &st))
- return -1;
- istate->timestamp.sec = (unsigned int)st.st_mtime;
- istate->timestamp.nsec = ST_MTIME_NSEC(st);
- return 0;
+ return istate->ops->write_index(istate, newfd);
}
/*
diff --git a/read-cache.h b/read-cache.h
new file mode 100644
index 0000000..f41ba75
--- /dev/null
+++ b/read-cache.h
@@ -0,0 +1,57 @@
+/* Index extensions.
+ *
+ * The first letter should be 'A'..'Z' for extensions that are not
+ * necessary for a correct operation (i.e. optimization data).
+ * When new extensions are added that _needs_ to be understood in
+ * order to correctly interpret the index file, pick character that
+ * is outside the range, to cause the reader to abort.
+ */
+
+#define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
+#define CACHE_EXT_TREE 0x54524545 /* "TREE" */
+#define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */
+
+#define INDEX_FORMAT_DEFAULT 3
+
+/*
+ * Basic data structures for the directory cache
+ */
+struct cache_version_header {
+ unsigned int hdr_signature;
+ unsigned int hdr_version;
+};
+
+struct index_ops {
+ int (*match_stat_basic)(struct cache_entry *ce, struct stat *st, int changed);
+ int (*verify_hdr)(void *mmap, unsigned long size);
+ int (*read_index)(struct index_state *istate, void *mmap, int mmap_size);
+ int (*write_index)(struct index_state *istate, int newfd);
+};
+
+extern struct index_ops v2_ops;
+
+#ifndef NEEDS_ALIGNED_ACCESS
+#define ntoh_s(var) ntohs(var)
+#define ntoh_l(var) ntohl(var)
+#else
+static inline uint16_t ntoh_s_force_align(void *p)
+{
+ uint16_t x;
+ memcpy(&x, p, sizeof(x));
+ return ntohs(x);
+}
+static inline uint32_t ntoh_l_force_align(void *p)
+{
+ uint32_t x;
+ memcpy(&x, p, sizeof(x));
+ return ntohl(x);
+}
+#define ntoh_s(var) ntoh_s_force_align(&(var))
+#define ntoh_l(var) ntoh_l_force_align(&(var))
+#endif
+
+extern int ce_modified_check_fs(struct cache_entry *ce, struct stat *st);
+extern int ce_match_stat_basic(struct index_state *istate,
+ struct cache_entry *ce, struct stat *st);
+extern int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce);
+extern void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce);
diff --git a/test-index-version.c b/test-index-version.c
index bfaad9e..3899a2f 100644
--- a/test-index-version.c
+++ b/test-index-version.c
@@ -1,8 +1,13 @@
#include "cache.h"
+struct cache_version_header {
+ unsigned int hdr_signature;
+ unsigned int hdr_version;
+};
+
int main(int argc, const char **argv)
{
- struct cache_header hdr;
+ struct cache_version_header hdr;
int version;
memset(&hdr,0,sizeof(hdr));
--
1.7.11.2
--
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