From: Han-Wen Nienhuys <hanwen@xxxxxxxxxx> For background, see the previous commit introducing the library. TODO: * Resolve spots marked with XXX * Test strategy? Example use: see t/t0031-reftable.sh Signed-off-by: Han-Wen Nienhuys <hanwen@xxxxxxxxxx> Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx> Co-authored-by: Jeff King <peff@xxxxxxxx> --- .../technical/repository-version.txt | 7 + Makefile | 26 +- builtin/clone.c | 5 +- builtin/init-db.c | 49 +- cache.h | 4 +- refs.c | 20 +- refs.h | 2 + refs/refs-internal.h | 1 + refs/reftable-backend.c | 1021 +++++++++++++++++ repository.c | 2 + repository.h | 3 + setup.c | 12 +- t/t0031-reftable.sh | 35 + 13 files changed, 1158 insertions(+), 29 deletions(-) create mode 100644 refs/reftable-backend.c create mode 100755 t/t0031-reftable.sh diff --git a/Documentation/technical/repository-version.txt b/Documentation/technical/repository-version.txt index 7844ef30ffd..72576235833 100644 --- a/Documentation/technical/repository-version.txt +++ b/Documentation/technical/repository-version.txt @@ -100,3 +100,10 @@ If set, by default "git config" reads from both "config" and multiple working directory mode, "config" file is shared while "config.worktree" is per-working directory (i.e., it's in GIT_COMMON_DIR/worktrees/<id>/config.worktree) + +==== `refStorage` + +Specifies the file format for the ref database. Values are `files` +(for the traditional packed + loose ref format) and `reftable` for the +binary reftable format. See https://github.com/google/reftable for +more information. diff --git a/Makefile b/Makefile index ef1ff2228f0..3d5a585d8fe 100644 --- a/Makefile +++ b/Makefile @@ -814,6 +814,7 @@ TEST_SHELL_PATH = $(SHELL_PATH) LIB_FILE = libgit.a XDIFF_LIB = xdiff/lib.a VCSSVN_LIB = vcs-svn/lib.a +REFTABLE_LIB = reftable/libreftable.a GENERATED_H += command-list.h @@ -960,6 +961,7 @@ LIB_OBJS += rebase-interactive.o LIB_OBJS += reflog-walk.o LIB_OBJS += refs.o LIB_OBJS += refs/files-backend.o +LIB_OBJS += refs/reftable-backend.o LIB_OBJS += refs/iterator.o LIB_OBJS += refs/packed-backend.o LIB_OBJS += refs/ref-cache.o @@ -1164,7 +1166,7 @@ THIRD_PARTY_SOURCES += compat/regex/% THIRD_PARTY_SOURCES += sha1collisiondetection/% THIRD_PARTY_SOURCES += sha1dc/% -GITLIBS = common-main.o $(LIB_FILE) $(XDIFF_LIB) +GITLIBS = common-main.o $(LIB_FILE) $(XDIFF_LIB) $(REFTABLE_LIB) EXTLIBS = GIT_USER_AGENT = git/$(GIT_VERSION) @@ -2348,11 +2350,28 @@ VCSSVN_OBJS += vcs-svn/fast_export.o VCSSVN_OBJS += vcs-svn/svndiff.o VCSSVN_OBJS += vcs-svn/svndump.o +REFTABLE_OBJS += reftable/basics.o +REFTABLE_OBJS += reftable/block.o +REFTABLE_OBJS += reftable/bytes.o +REFTABLE_OBJS += reftable/file.o +REFTABLE_OBJS += reftable/iter.o +REFTABLE_OBJS += reftable/merged.o +REFTABLE_OBJS += reftable/pq.o +REFTABLE_OBJS += reftable/reader.o +REFTABLE_OBJS += reftable/record.o +REFTABLE_OBJS += reftable/slice.o +REFTABLE_OBJS += reftable/stack.o +REFTABLE_OBJS += reftable/tree.o +REFTABLE_OBJS += reftable/writer.o +REFTABLE_OBJS += reftable/zlib-compat.o + + TEST_OBJS := $(patsubst %$X,%.o,$(TEST_PROGRAMS)) $(patsubst %,t/helper/%,$(TEST_BUILTINS_OBJS)) OBJECTS := $(LIB_OBJS) $(BUILTIN_OBJS) $(PROGRAM_OBJS) $(TEST_OBJS) \ $(XDIFF_OBJS) \ $(VCSSVN_OBJS) \ $(FUZZ_OBJS) \ + $(REFTABLE_OBJS) \ common-main.o \ git.o ifndef NO_CURL @@ -2489,6 +2508,9 @@ $(XDIFF_LIB): $(XDIFF_OBJS) $(VCSSVN_LIB): $(VCSSVN_OBJS) $(QUIET_AR)$(RM) $@ && $(AR) $(ARFLAGS) $@ $^ +$(REFTABLE_LIB): $(REFTABLE_OBJS) + $(QUIET_AR)$(RM) $@ && $(AR) $(ARFLAGS) $@ $^ + export DEFAULT_EDITOR DEFAULT_PAGER Documentation/GIT-EXCLUDED-PROGRAMS: FORCE @@ -3104,7 +3126,7 @@ cocciclean: clean: profile-clean coverage-clean cocciclean $(RM) *.res $(RM) $(OBJECTS) - $(RM) $(LIB_FILE) $(XDIFF_LIB) $(VCSSVN_LIB) + $(RM) $(LIB_FILE) $(XDIFF_LIB) $(VCSSVN_LIB) $(REFTABLE_LIB) $(RM) $(ALL_PROGRAMS) $(SCRIPT_LIB) $(BUILT_INS) git$X $(RM) $(TEST_PROGRAMS) $(RM) $(FUZZ_PROGRAMS) diff --git a/builtin/clone.c b/builtin/clone.c index d8b1f413aad..3bead96e447 100644 --- a/builtin/clone.c +++ b/builtin/clone.c @@ -1109,7 +1109,10 @@ int cmd_clone(int argc, const char **argv, const char *prefix) } } - init_db(git_dir, real_git_dir, option_template, GIT_HASH_UNKNOWN, INIT_DB_QUIET); + init_db(git_dir, real_git_dir, option_template, + GIT_HASH_UNKNOWN, + DEFAULT_REF_STORAGE, /* XXX */ + INIT_DB_QUIET); if (real_git_dir) git_dir = real_git_dir; diff --git a/builtin/init-db.c b/builtin/init-db.c index 3b50b1aa0e5..888b421338d 100644 --- a/builtin/init-db.c +++ b/builtin/init-db.c @@ -178,7 +178,7 @@ static int needs_work_tree_config(const char *git_dir, const char *work_tree) return 1; } -void initialize_repository_version(int hash_algo) +void initialize_repository_version(int hash_algo, const char *ref_storage_format) { char repo_version_string[10]; int repo_version = GIT_REPO_VERSION; @@ -188,7 +188,7 @@ void initialize_repository_version(int hash_algo) die(_("The hash algorithm %s is not supported in this build."), hash_algos[hash_algo].name); #endif - if (hash_algo != GIT_HASH_SHA1) + if (hash_algo != GIT_HASH_SHA1 || !strcmp(ref_storage_format, "reftable")) repo_version = GIT_REPO_VERSION_READ; /* This forces creation of new config file */ @@ -238,6 +238,7 @@ static int create_default_files(const char *template_path, is_bare_repository_cfg = init_is_bare_repository; if (init_shared_repository != -1) set_shared_repository(init_shared_repository); + the_repository->ref_storage_format = xstrdup(fmt->ref_storage); /* * We would have created the above under user's umask -- under @@ -247,6 +248,15 @@ static int create_default_files(const char *template_path, adjust_shared_perm(get_git_dir()); } + /* + * Check to see if .git/HEAD exists; this must happen before + * initializing the ref db, because we want to see if there is an + * existing HEAD. + */ + path = git_path_buf(&buf, "HEAD"); + reinit = (!access(path, R_OK) || + readlink(path, junk, sizeof(junk) - 1) != -1); + /* * We need to create a "refs" dir in any case so that older * versions of git can tell that this is a repository. @@ -259,15 +269,17 @@ static int create_default_files(const char *template_path, * Create the default symlink from ".git/HEAD" to the "master" * branch, if it does not exist yet. */ - path = git_path_buf(&buf, "HEAD"); - reinit = (!access(path, R_OK) - || readlink(path, junk, sizeof(junk)-1) != -1); if (!reinit) { if (create_symref("HEAD", "refs/heads/master", NULL) < 0) exit(1); + } else { + /* + * XXX should check whether our ref backend matches the + * original one; if not, either die() or convert + */ } - initialize_repository_version(fmt->hash_algo); + initialize_repository_version(fmt->hash_algo, fmt->ref_storage); /* Check filemode trustability */ path = git_path_buf(&buf, "config"); @@ -381,7 +393,8 @@ static void validate_hash_algorithm(struct repository_format *repo_fmt, int hash } int init_db(const char *git_dir, const char *real_git_dir, - const char *template_dir, int hash, unsigned int flags) + const char *template_dir, int hash, const char *ref_storage_format, + unsigned int flags) { int reinit; int exist_ok = flags & INIT_DB_EXIST_OK; @@ -420,6 +433,7 @@ int init_db(const char *git_dir, const char *real_git_dir, * is an attempt to reinitialize new repository with an old tool. */ check_repository_format(&repo_fmt); + repo_fmt.ref_storage = xstrdup(ref_storage_format); validate_hash_algorithm(&repo_fmt, hash); @@ -448,6 +462,8 @@ int init_db(const char *git_dir, const char *real_git_dir, git_config_set("receive.denyNonFastforwards", "true"); } + git_config_set("extensions.refStorage", ref_storage_format); + if (!(flags & INIT_DB_QUIET)) { int len = strlen(git_dir); @@ -521,6 +537,7 @@ static const char *const init_db_usage[] = { int cmd_init_db(int argc, const char **argv, const char *prefix) { const char *git_dir; + const char *ref_storage_format = DEFAULT_REF_STORAGE; const char *real_git_dir = NULL; const char *work_tree; const char *template_dir = NULL; @@ -528,15 +545,18 @@ int cmd_init_db(int argc, const char **argv, const char *prefix) const char *object_format = NULL; int hash_algo = GIT_HASH_UNKNOWN; const struct option init_db_options[] = { - OPT_STRING(0, "template", &template_dir, N_("template-directory"), - N_("directory from which templates will be used")), + OPT_STRING(0, "template", &template_dir, + N_("template-directory"), + N_("directory from which templates will be used")), OPT_SET_INT(0, "bare", &is_bare_repository_cfg, - N_("create a bare repository"), 1), + N_("create a bare repository"), 1), { OPTION_CALLBACK, 0, "shared", &init_shared_repository, - N_("permissions"), - N_("specify that the git repository is to be shared amongst several users"), - PARSE_OPT_OPTARG | PARSE_OPT_NONEG, shared_callback, 0}, + N_("permissions"), + N_("specify that the git repository is to be shared amongst several users"), + PARSE_OPT_OPTARG | PARSE_OPT_NONEG, shared_callback, 0 }, OPT_BIT('q', "quiet", &flags, N_("be quiet"), INIT_DB_QUIET), + OPT_STRING(0, "ref-storage", &ref_storage_format, N_("backend"), + N_("the ref storage format to use")), OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"), N_("separate git dir from working tree")), OPT_STRING(0, "object-format", &object_format, N_("hash"), @@ -646,9 +666,10 @@ int cmd_init_db(int argc, const char **argv, const char *prefix) } UNLEAK(real_git_dir); + UNLEAK(ref_storage_format); UNLEAK(git_dir); UNLEAK(work_tree); flags |= INIT_DB_EXIST_OK; - return init_db(git_dir, real_git_dir, template_dir, hash_algo, flags); + return init_db(git_dir, real_git_dir, template_dir, hash_algo, ref_storage_format, flags); } diff --git a/cache.h b/cache.h index c77b95870a5..83c4908ba06 100644 --- a/cache.h +++ b/cache.h @@ -628,8 +628,9 @@ int path_inside_repo(const char *prefix, const char *path); int init_db(const char *git_dir, const char *real_git_dir, const char *template_dir, int hash_algo, + const char *ref_storage_format, unsigned int flags); -void initialize_repository_version(int hash_algo); +void initialize_repository_version(int hash_algo, const char *ref_storage_format); void sanitize_stdfds(void); int daemonize(void); @@ -1043,6 +1044,7 @@ struct repository_format { int is_bare; int hash_algo; char *work_tree; + char *ref_storage; struct string_list unknown_extensions; }; diff --git a/refs.c b/refs.c index 3b9742d03cb..7b90b84f29c 100644 --- a/refs.c +++ b/refs.c @@ -20,7 +20,7 @@ /* * List of all available backends */ -static struct ref_storage_be *refs_backends = &refs_be_files; +static struct ref_storage_be *refs_backends = &refs_be_reftable; static struct ref_storage_be *find_ref_storage_backend(const char *name) { @@ -1836,13 +1836,13 @@ static struct ref_store *lookup_ref_store_map(struct hashmap *map, * Create, record, and return a ref_store instance for the specified * gitdir. */ -static struct ref_store *ref_store_init(const char *gitdir, +static struct ref_store *ref_store_init(const char *gitdir, const char *be_name, unsigned int flags) { - const char *be_name = "files"; - struct ref_storage_be *be = find_ref_storage_backend(be_name); + struct ref_storage_be *be; struct ref_store *refs; + be = find_ref_storage_backend(be_name); if (!be) BUG("reference backend %s is unknown", be_name); @@ -1858,7 +1858,10 @@ struct ref_store *get_main_ref_store(struct repository *r) if (!r->gitdir) BUG("attempting to get main_ref_store outside of repository"); - r->refs = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS); + r->refs = ref_store_init(r->gitdir, + r->ref_storage_format ? r->ref_storage_format : + DEFAULT_REF_STORAGE, + REF_STORE_ALL_CAPS); return r->refs; } @@ -1913,7 +1916,7 @@ struct ref_store *get_submodule_ref_store(const char *submodule) goto done; /* assume that add_submodule_odb() has been called */ - refs = ref_store_init(submodule_sb.buf, + refs = ref_store_init(submodule_sb.buf, DEFAULT_REF_STORAGE, /* XXX */ REF_STORE_READ | REF_STORE_ODB); register_ref_store_map(&submodule_ref_stores, "submodule", refs, submodule); @@ -1927,6 +1930,7 @@ struct ref_store *get_submodule_ref_store(const char *submodule) struct ref_store *get_worktree_ref_store(const struct worktree *wt) { + const char *format = DEFAULT_REF_STORAGE; /* XXX */ struct ref_store *refs; const char *id; @@ -1940,9 +1944,9 @@ struct ref_store *get_worktree_ref_store(const struct worktree *wt) if (wt->id) refs = ref_store_init(git_common_path("worktrees/%s", wt->id), - REF_STORE_ALL_CAPS); + format, REF_STORE_ALL_CAPS); else - refs = ref_store_init(get_git_common_dir(), + refs = ref_store_init(get_git_common_dir(), format, REF_STORE_ALL_CAPS); if (refs) diff --git a/refs.h b/refs.h index 87c9ec921b9..d7fbbe26e6a 100644 --- a/refs.h +++ b/refs.h @@ -9,6 +9,8 @@ struct string_list; struct string_list_item; struct worktree; +#define DEFAULT_REF_STORAGE "files" + /* * Resolve a reference, recursively following symbolic refererences. * diff --git a/refs/refs-internal.h b/refs/refs-internal.h index 3490aac3a40..cafe5b97376 100644 --- a/refs/refs-internal.h +++ b/refs/refs-internal.h @@ -661,6 +661,7 @@ struct ref_storage_be { }; extern struct ref_storage_be refs_be_files; +extern struct ref_storage_be refs_be_reftable; extern struct ref_storage_be refs_be_packed; /* diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c new file mode 100644 index 00000000000..e114ab71342 --- /dev/null +++ b/refs/reftable-backend.c @@ -0,0 +1,1021 @@ +#include "../cache.h" +#include "../config.h" +#include "../refs.h" +#include "refs-internal.h" +#include "../iterator.h" +#include "../lockfile.h" +#include "../chdir-notify.h" + +#include "../reftable/reftable.h" + +extern struct ref_storage_be refs_be_reftable; + +struct git_reftable_ref_store { + struct ref_store base; + unsigned int store_flags; + + int err; + char *reftable_dir; + struct reftable_stack *stack; +}; + +static void clear_reftable_log_record(struct reftable_log_record *log) +{ + log->old_hash = NULL; + log->new_hash = NULL; + log->message = NULL; + log->ref_name = NULL; + reftable_log_record_clear(log); +} + +static void fill_reftable_log_record(struct reftable_log_record *log) +{ + const char *info = git_committer_info(0); + struct ident_split split = { NULL }; + int result = split_ident_line(&split, info, strlen(info)); + int sign = 1; + assert(0 == result); + + reftable_log_record_clear(log); + log->name = + xstrndup(split.name_begin, split.name_end - split.name_begin); + log->email = + xstrndup(split.mail_begin, split.mail_end - split.mail_begin); + log->time = atol(split.date_begin); + if (*split.tz_begin == '-') { + sign = -1; + split.tz_begin++; + } + if (*split.tz_begin == '+') { + sign = 1; + split.tz_begin++; + } + + log->tz_offset = sign * atoi(split.tz_begin); +} + +static struct ref_store *git_reftable_ref_store_create(const char *path, + unsigned int store_flags) +{ + struct git_reftable_ref_store *refs = xcalloc(1, sizeof(*refs)); + struct ref_store *ref_store = (struct ref_store *)refs; + struct reftable_write_options cfg = { + .block_size = 4096, + .hash_id = the_hash_algo->format_id, + }; + struct strbuf sb = STRBUF_INIT; + + base_ref_store_init(ref_store, &refs_be_reftable); + refs->store_flags = store_flags; + + strbuf_addf(&sb, "%s/reftable", path); + refs->reftable_dir = xstrdup(sb.buf); + strbuf_reset(&sb); + + strbuf_addf(&sb, "%s/refs", path); + safe_create_dir(sb.buf, 1); + strbuf_reset(&sb); + + strbuf_addf(&sb, "%s/HEAD", path); + write_file(sb.buf, "ref: refs/.invalid"); + strbuf_reset(&sb); + + strbuf_addf(&sb, "%s/refs/heads", path); + write_file(sb.buf, "this repository uses the reftable format"); + + refs->err = reftable_new_stack(&refs->stack, refs->reftable_dir, cfg); + strbuf_release(&sb); + return ref_store; +} + +static int reftable_init_db(struct ref_store *ref_store, struct strbuf *err) +{ + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + safe_create_dir(refs->reftable_dir, 1); + return 0; +} + +struct git_reftable_iterator { + struct ref_iterator base; + struct reftable_iterator iter; + struct reftable_ref_record ref; + struct object_id oid; + struct ref_store *ref_store; + unsigned int flags; + int err; + const char *prefix; +}; + +static int reftable_ref_iterator_advance(struct ref_iterator *ref_iterator) +{ + struct git_reftable_iterator *ri = + (struct git_reftable_iterator *)ref_iterator; + while (ri->err == 0) { + ri->err = reftable_iterator_next_ref(ri->iter, &ri->ref); + if (ri->err) { + break; + } + + ri->base.refname = ri->ref.ref_name; + if (ri->prefix != NULL && + strncmp(ri->prefix, ri->ref.ref_name, strlen(ri->prefix))) { + ri->err = 1; + break; + } + if (ri->flags & DO_FOR_EACH_PER_WORKTREE_ONLY && + ref_type(ri->base.refname) != REF_TYPE_PER_WORKTREE) + continue; + + ri->base.flags = 0; + if (ri->ref.value != NULL) { + hashcpy(ri->oid.hash, ri->ref.value); + } else if (ri->ref.target != NULL) { + int out_flags = 0; + const char *resolved = refs_resolve_ref_unsafe( + ri->ref_store, ri->ref.ref_name, + RESOLVE_REF_READING, &ri->oid, &out_flags); + ri->base.flags = out_flags; + if (resolved == NULL && + !(ri->flags & DO_FOR_EACH_INCLUDE_BROKEN) && + (ri->base.flags & REF_ISBROKEN)) { + continue; + } + } + + ri->base.oid = &ri->oid; + if (!(ri->flags & DO_FOR_EACH_INCLUDE_BROKEN) && + !ref_resolves_to_object(ri->base.refname, ri->base.oid, + ri->base.flags)) { + continue; + } + + break; + } + + if (ri->err > 0) { + return ITER_DONE; + } + if (ri->err < 0) { + return ITER_ERROR; + } + + return ITER_OK; +} + +static int reftable_ref_iterator_peel(struct ref_iterator *ref_iterator, + struct object_id *peeled) +{ + struct git_reftable_iterator *ri = + (struct git_reftable_iterator *)ref_iterator; + if (ri->ref.target_value != NULL) { + hashcpy(peeled->hash, ri->ref.target_value); + return 0; + } + + return -1; +} + +static int reftable_ref_iterator_abort(struct ref_iterator *ref_iterator) +{ + struct git_reftable_iterator *ri = + (struct git_reftable_iterator *)ref_iterator; + reftable_ref_record_clear(&ri->ref); + reftable_iterator_destroy(&ri->iter); + return 0; +} + +static struct ref_iterator_vtable reftable_ref_iterator_vtable = { + reftable_ref_iterator_advance, reftable_ref_iterator_peel, + reftable_ref_iterator_abort +}; + +static struct ref_iterator * +reftable_ref_iterator_begin(struct ref_store *ref_store, const char *prefix, + unsigned int flags) +{ + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + struct git_reftable_iterator *ri = xcalloc(1, sizeof(*ri)); + struct reftable_merged_table *mt = NULL; + + if (refs->err < 0) { + ri->err = refs->err; + } else { + mt = reftable_stack_merged_table(refs->stack); + ri->err = reftable_merged_table_seek_ref(mt, &ri->iter, prefix); + } + + base_ref_iterator_init(&ri->base, &reftable_ref_iterator_vtable, 1); + ri->prefix = prefix; + ri->base.oid = &ri->oid; + ri->flags = flags; + ri->ref_store = ref_store; + return &ri->base; +} + +static int reftable_transaction_prepare(struct ref_store *ref_store, + struct ref_transaction *transaction, + struct strbuf *err) +{ + return 0; +} + +static int reftable_transaction_abort(struct ref_store *ref_store, + struct ref_transaction *transaction, + struct strbuf *err) +{ + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + (void)refs; + return 0; +} + +static int reftable_check_old_oid(struct ref_store *refs, const char *refname, + struct object_id *want_oid) +{ + struct object_id out_oid; + int out_flags = 0; + const char *resolved = refs_resolve_ref_unsafe( + refs, refname, RESOLVE_REF_READING, &out_oid, &out_flags); + if (is_null_oid(want_oid) != (resolved == NULL)) { + return LOCK_ERROR; + } + + if (resolved != NULL && !oideq(&out_oid, want_oid)) { + return LOCK_ERROR; + } + + return 0; +} + +static int ref_update_cmp(const void *a, const void *b) +{ + return strcmp(((struct ref_update *)a)->refname, + ((struct ref_update *)b)->refname); +} + +static int write_transaction_table(struct reftable_writer *writer, void *arg) +{ + struct ref_transaction *transaction = (struct ref_transaction *)arg; + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)transaction->ref_store; + uint64_t ts = reftable_stack_next_update_index(refs->stack); + int err = 0; + struct reftable_log_record *logs = + calloc(transaction->nr, sizeof(*logs)); + struct ref_update **sorted = + malloc(transaction->nr * sizeof(struct ref_update *)); + COPY_ARRAY(sorted, transaction->updates, transaction->nr); + QSORT(sorted, transaction->nr, ref_update_cmp); + reftable_writer_set_limits(writer, ts, ts); + + for (int i = 0; i < transaction->nr; i++) { + struct ref_update *u = sorted[i]; + if (u->flags & REF_HAVE_OLD) { + err = reftable_check_old_oid(transaction->ref_store, + u->refname, &u->old_oid); + if (err < 0) { + goto exit; + } + } + } + + for (int i = 0; i < transaction->nr; i++) { + struct ref_update *u = sorted[i]; + struct reftable_log_record *log = &logs[i]; + fill_reftable_log_record(log); + log->ref_name = (char *)u->refname; + log->old_hash = u->old_oid.hash; + log->new_hash = u->new_oid.hash; + log->update_index = ts; + log->message = u->msg; + + if (u->flags & REF_HAVE_NEW) { + struct object_id out_oid; + int out_flags = 0; + /* Memory owned by refs_resolve_ref_unsafe, no need to + * free(). */ + const char *resolved = refs_resolve_ref_unsafe( + transaction->ref_store, u->refname, 0, &out_oid, + &out_flags); + struct reftable_ref_record ref = { NULL }; + ref.ref_name = + (char *)(resolved ? resolved : u->refname); + log->ref_name = ref.ref_name; + ref.value = u->new_oid.hash; + ref.update_index = ts; + err = reftable_writer_add_ref(writer, &ref); + if (err < 0) { + goto exit; + } + } + } + + for (int i = 0; i < transaction->nr; i++) { + err = reftable_writer_add_log(writer, &logs[i]); + clear_reftable_log_record(&logs[i]); + if (err < 0) { + goto exit; + } + } + +exit: + free(logs); + free(sorted); + return err; +} + +static int reftable_transaction_commit(struct ref_store *ref_store, + struct ref_transaction *transaction, + struct strbuf *errmsg) +{ + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + int err = 0; + if (refs->err < 0) { + return refs->err; + } + + err = reftable_stack_add(refs->stack, &write_transaction_table, + transaction); + if (err < 0) { + strbuf_addf(errmsg, "reftable: transaction failure %s", + reftable_error_str(err)); + return -1; + } + + return 0; +} + +static int reftable_transaction_finish(struct ref_store *ref_store, + struct ref_transaction *transaction, + struct strbuf *err) +{ + return reftable_transaction_commit(ref_store, transaction, err); +} + +struct write_delete_refs_arg { + struct reftable_stack *stack; + struct string_list *refnames; + const char *logmsg; + unsigned int flags; +}; + +static int write_delete_refs_table(struct reftable_writer *writer, void *argv) +{ + struct write_delete_refs_arg *arg = + (struct write_delete_refs_arg *)argv; + uint64_t ts = reftable_stack_next_update_index(arg->stack); + int err = 0; + + reftable_writer_set_limits(writer, ts, ts); + for (int i = 0; i < arg->refnames->nr; i++) { + struct reftable_ref_record ref = { + .ref_name = (char *)arg->refnames->items[i].string, + .update_index = ts, + }; + err = reftable_writer_add_ref(writer, &ref); + if (err < 0) { + return err; + } + } + + for (int i = 0; i < arg->refnames->nr; i++) { + struct reftable_log_record log = { NULL }; + struct reftable_ref_record current = { NULL }; + fill_reftable_log_record(&log); + log.message = xstrdup(arg->logmsg); + log.new_hash = NULL; + log.old_hash = NULL; + log.update_index = ts; + log.ref_name = (char *)arg->refnames->items[i].string; + + if (reftable_stack_read_ref(arg->stack, log.ref_name, + ¤t) == 0) { + log.old_hash = current.value; + } + err = reftable_writer_add_log(writer, &log); + log.old_hash = NULL; + reftable_ref_record_clear(¤t); + + clear_reftable_log_record(&log); + if (err < 0) { + return err; + } + } + return 0; +} + +static int reftable_delete_refs(struct ref_store *ref_store, const char *msg, + struct string_list *refnames, + unsigned int flags) +{ + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + struct write_delete_refs_arg arg = { + .stack = refs->stack, + .refnames = refnames, + .logmsg = msg, + .flags = flags, + }; + if (refs->err < 0) { + return refs->err; + } + + return reftable_stack_add(refs->stack, &write_delete_refs_table, &arg); +} + +static int reftable_pack_refs(struct ref_store *ref_store, unsigned int flags) +{ + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + if (refs->err < 0) { + return refs->err; + } + return reftable_stack_compact_all(refs->stack, NULL); +} + +struct write_create_symref_arg { + struct git_reftable_ref_store *refs; + const char *refname; + const char *target; + const char *logmsg; +}; + +static int write_create_symref_table(struct reftable_writer *writer, void *arg) +{ + struct write_create_symref_arg *create = + (struct write_create_symref_arg *)arg; + uint64_t ts = reftable_stack_next_update_index(create->refs->stack); + int err = 0; + + struct reftable_ref_record ref = { + .ref_name = (char *)create->refname, + .target = (char *)create->target, + .update_index = ts, + }; + reftable_writer_set_limits(writer, ts, ts); + err = reftable_writer_add_ref(writer, &ref); + if (err < 0) { + return err; + } + + { + struct reftable_log_record log = { NULL }; + struct object_id new_oid; + struct object_id old_oid; + struct reftable_ref_record current = { NULL }; + reftable_stack_read_ref(create->refs->stack, create->refname, + ¤t); + + fill_reftable_log_record(&log); + log.ref_name = current.ref_name; + if (refs_resolve_ref_unsafe( + (struct ref_store *)create->refs, create->refname, + RESOLVE_REF_READING, &old_oid, NULL) != NULL) { + log.old_hash = old_oid.hash; + } + + if (refs_resolve_ref_unsafe((struct ref_store *)create->refs, + create->target, RESOLVE_REF_READING, + &new_oid, NULL) != NULL) { + log.new_hash = new_oid.hash; + } + + if (log.old_hash != NULL || log.new_hash != NULL) { + reftable_writer_add_log(writer, &log); + } + log.ref_name = NULL; + log.old_hash = NULL; + log.new_hash = NULL; + clear_reftable_log_record(&log); + } + return 0; +} + +static int reftable_create_symref(struct ref_store *ref_store, + const char *refname, const char *target, + const char *logmsg) +{ + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + struct write_create_symref_arg arg = { .refs = refs, + .refname = refname, + .target = target, + .logmsg = logmsg }; + if (refs->err < 0) { + return refs->err; + } + return reftable_stack_add(refs->stack, &write_create_symref_table, + &arg); +} + +struct write_rename_arg { + struct reftable_stack *stack; + const char *oldname; + const char *newname; + const char *logmsg; +}; + +static int write_rename_table(struct reftable_writer *writer, void *argv) +{ + struct write_rename_arg *arg = (struct write_rename_arg *)argv; + uint64_t ts = reftable_stack_next_update_index(arg->stack); + struct reftable_ref_record ref = { NULL }; + int err = reftable_stack_read_ref(arg->stack, arg->oldname, &ref); + + if (err) { + goto exit; + } + + /* XXX do ref renames overwrite the target? */ + if (reftable_stack_read_ref(arg->stack, arg->newname, &ref) == 0) { + goto exit; + } + + free(ref.ref_name); + ref.ref_name = strdup(arg->newname); + reftable_writer_set_limits(writer, ts, ts); + ref.update_index = ts; + + { + struct reftable_ref_record todo[2] = { { NULL } }; + todo[0].ref_name = (char *)arg->oldname; + todo[0].update_index = ts; + /* leave todo[0] empty */ + todo[1] = ref; + todo[1].update_index = ts; + + err = reftable_writer_add_refs(writer, todo, 2); + if (err < 0) { + goto exit; + } + } + + if (ref.value != NULL) { + struct reftable_log_record todo[2] = { { NULL } }; + fill_reftable_log_record(&todo[0]); + fill_reftable_log_record(&todo[1]); + + todo[0].ref_name = (char *)arg->oldname; + todo[0].update_index = ts; + todo[0].message = (char *)arg->logmsg; + todo[0].old_hash = ref.value; + todo[0].new_hash = NULL; + + todo[1].ref_name = (char *)arg->newname; + todo[1].update_index = ts; + todo[1].old_hash = NULL; + todo[1].new_hash = ref.value; + todo[1].message = (char *)arg->logmsg; + + err = reftable_writer_add_logs(writer, todo, 2); + + clear_reftable_log_record(&todo[0]); + clear_reftable_log_record(&todo[1]); + + if (err < 0) { + goto exit; + } + + } else { + /* XXX symrefs? */ + } + +exit: + reftable_ref_record_clear(&ref); + return err; +} + +static int reftable_rename_ref(struct ref_store *ref_store, + const char *oldrefname, const char *newrefname, + const char *logmsg) +{ + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + struct write_rename_arg arg = { + .stack = refs->stack, + .oldname = oldrefname, + .newname = newrefname, + .logmsg = logmsg, + }; + if (refs->err < 0) { + return refs->err; + } + + return reftable_stack_add(refs->stack, &write_rename_table, &arg); +} + +static int reftable_copy_ref(struct ref_store *ref_store, + const char *oldrefname, const char *newrefname, + const char *logmsg) +{ + BUG("reftable reference store does not support copying references"); +} + +struct reftable_reflog_ref_iterator { + struct ref_iterator base; + struct reftable_iterator iter; + struct reftable_log_record log; + struct object_id oid; + char *last_name; +}; + +static int +reftable_reflog_ref_iterator_advance(struct ref_iterator *ref_iterator) +{ + struct reftable_reflog_ref_iterator *ri = + (struct reftable_reflog_ref_iterator *)ref_iterator; + + while (1) { + int err = reftable_iterator_next_log(ri->iter, &ri->log); + if (err > 0) { + return ITER_DONE; + } + if (err < 0) { + return ITER_ERROR; + } + + if (reftable_log_record_is_deletion(&ri->log)) { + /* XXX - Why does the reftable_stack filter these? */ + continue; + } + ri->base.refname = ri->log.ref_name; + if (ri->last_name != NULL && + !strcmp(ri->log.ref_name, ri->last_name)) { + /* we want the refnames that we have reflogs for, so we + * skip if we've already produced this name. This could + * be faster by seeking directly to + * reflog@update_index==0. + */ + continue; + } + + free(ri->last_name); + ri->last_name = xstrdup(ri->log.ref_name); + hashcpy(ri->oid.hash, ri->log.new_hash); + return ITER_OK; + } +} + +static int reftable_reflog_ref_iterator_peel(struct ref_iterator *ref_iterator, + struct object_id *peeled) +{ + BUG("not supported."); + return -1; +} + +static int reftable_reflog_ref_iterator_abort(struct ref_iterator *ref_iterator) +{ + struct reftable_reflog_ref_iterator *ri = + (struct reftable_reflog_ref_iterator *)ref_iterator; + reftable_log_record_clear(&ri->log); + reftable_iterator_destroy(&ri->iter); + return 0; +} + +static struct ref_iterator_vtable reftable_reflog_ref_iterator_vtable = { + reftable_reflog_ref_iterator_advance, reftable_reflog_ref_iterator_peel, + reftable_reflog_ref_iterator_abort +}; + +static struct ref_iterator * +reftable_reflog_iterator_begin(struct ref_store *ref_store) +{ + struct reftable_reflog_ref_iterator *ri = xcalloc(sizeof(*ri), 1); + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + + struct reftable_merged_table *mt = + reftable_stack_merged_table(refs->stack); + int err = reftable_merged_table_seek_log(mt, &ri->iter, ""); + if (err < 0) { + free(ri); + return NULL; + } + + base_ref_iterator_init(&ri->base, &reftable_reflog_ref_iterator_vtable, + 1); + ri->base.oid = &ri->oid; + + return (struct ref_iterator *)ri; +} + +static int +reftable_for_each_reflog_ent_newest_first(struct ref_store *ref_store, + const char *refname, + each_reflog_ent_fn fn, void *cb_data) +{ + struct reftable_iterator it = { NULL }; + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + struct reftable_merged_table *mt = NULL; + int err = 0; + struct reftable_log_record log = { NULL }; + + if (refs->err < 0) { + return refs->err; + } + + mt = reftable_stack_merged_table(refs->stack); + err = reftable_merged_table_seek_log(mt, &it, refname); + while (err == 0) { + err = reftable_iterator_next_log(it, &log); + if (err != 0) { + break; + } + + if (strcmp(log.ref_name, refname)) { + break; + } + + { + struct object_id old_oid; + struct object_id new_oid; + const char *full_committer = ""; + + hashcpy(old_oid.hash, log.old_hash); + hashcpy(new_oid.hash, log.new_hash); + + full_committer = fmt_ident(log.name, log.email, + WANT_COMMITTER_IDENT, + /*date*/ NULL, + IDENT_NO_DATE); + if (fn(&old_oid, &new_oid, full_committer, log.time, + log.tz_offset, log.message, cb_data)) { + err = -1; + break; + } + } + } + + reftable_log_record_clear(&log); + reftable_iterator_destroy(&it); + if (err > 0) { + err = 0; + } + return err; +} + +static int +reftable_for_each_reflog_ent_oldest_first(struct ref_store *ref_store, + const char *refname, + each_reflog_ent_fn fn, void *cb_data) +{ + struct reftable_iterator it = { NULL }; + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + struct reftable_merged_table *mt = NULL; + struct reftable_log_record *logs = NULL; + int cap = 0; + int len = 0; + int err = 0; + + if (refs->err < 0) { + return refs->err; + } + mt = reftable_stack_merged_table(refs->stack); + err = reftable_merged_table_seek_log(mt, &it, refname); + + while (err == 0) { + struct reftable_log_record log = { NULL }; + err = reftable_iterator_next_log(it, &log); + if (err != 0) { + break; + } + + if (strcmp(log.ref_name, refname)) { + break; + } + + if (len == cap) { + cap = 2 * cap + 1; + logs = realloc(logs, cap * sizeof(*logs)); + } + + logs[len++] = log; + } + + for (int i = len; i--;) { + struct reftable_log_record *log = &logs[i]; + struct object_id old_oid; + struct object_id new_oid; + const char *full_committer = ""; + + hashcpy(old_oid.hash, log->old_hash); + hashcpy(new_oid.hash, log->new_hash); + + full_committer = fmt_ident(log->name, log->email, + WANT_COMMITTER_IDENT, NULL, + IDENT_NO_DATE); + if (!fn(&old_oid, &new_oid, full_committer, log->time, + log->tz_offset, log->message, cb_data)) { + err = -1; + break; + } + } + + for (int i = 0; i < len; i++) { + reftable_log_record_clear(&logs[i]); + } + free(logs); + + reftable_iterator_destroy(&it); + if (err > 0) { + err = 0; + } + return err; +} + +static int reftable_reflog_exists(struct ref_store *ref_store, + const char *refname) +{ + /* always exists. */ + return 1; +} + +static int reftable_create_reflog(struct ref_store *ref_store, + const char *refname, int force_create, + struct strbuf *err) +{ + return 0; +} + +static int reftable_delete_reflog(struct ref_store *ref_store, + const char *refname) +{ + return 0; +} + +struct reflog_expiry_arg { + struct git_reftable_ref_store *refs; + struct reftable_log_record *tombstones; + int len; + int cap; +}; + +static void clear_log_tombstones(struct reflog_expiry_arg *arg) +{ + int i = 0; + for (; i < arg->len; i++) { + reftable_log_record_clear(&arg->tombstones[i]); + } + + FREE_AND_NULL(arg->tombstones); +} + +static void add_log_tombstone(struct reflog_expiry_arg *arg, + const char *refname, uint64_t ts) +{ + struct reftable_log_record tombstone = { + .ref_name = xstrdup(refname), + .update_index = ts, + }; + if (arg->len == arg->cap) { + arg->cap = 2 * arg->cap + 1; + arg->tombstones = + realloc(arg->tombstones, arg->cap * sizeof(tombstone)); + } + arg->tombstones[arg->len++] = tombstone; +} + +static int write_reflog_expiry_table(struct reftable_writer *writer, void *argv) +{ + struct reflog_expiry_arg *arg = (struct reflog_expiry_arg *)argv; + uint64_t ts = reftable_stack_next_update_index(arg->refs->stack); + int i = 0; + reftable_writer_set_limits(writer, ts, ts); + for (i = 0; i < arg->len; i++) { + int err = reftable_writer_add_log(writer, &arg->tombstones[i]); + if (err) { + return err; + } + } + return 0; +} + +static int reftable_reflog_expire(struct ref_store *ref_store, + const char *refname, + const struct object_id *oid, + unsigned int flags, + reflog_expiry_prepare_fn prepare_fn, + reflog_expiry_should_prune_fn should_prune_fn, + reflog_expiry_cleanup_fn cleanup_fn, + void *policy_cb_data) +{ + /* + For log expiry, we write tombstones in place of the expired entries, + This means that the entries are still retrievable by delving into the + stack, and expiring entries paradoxically takes extra memory. + + This memory is only reclaimed when some operation issues a + reftable_pack_refs(), which will compact the entire stack and get rid + of deletion entries. + + It would be better if the refs backend supported an API that sets a + criterion for all refs, passing the criterion to pack_refs(). + */ + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + struct reftable_merged_table *mt = NULL; + struct reflog_expiry_arg arg = { + .refs = refs, + }; + struct reftable_log_record log = { NULL }; + struct reftable_iterator it = { NULL }; + int err = 0; + if (refs->err < 0) { + return refs->err; + } + + mt = reftable_stack_merged_table(refs->stack); + err = reftable_merged_table_seek_log(mt, &it, refname); + if (err < 0) { + return err; + } + + while (1) { + struct object_id ooid; + struct object_id noid; + + int err = reftable_iterator_next_log(it, &log); + if (err < 0) { + return err; + } + + if (err > 0 || strcmp(log.ref_name, refname)) { + break; + } + hashcpy(ooid.hash, log.old_hash); + hashcpy(noid.hash, log.new_hash); + + if (should_prune_fn(&ooid, &noid, log.email, + (timestamp_t)log.time, log.tz_offset, + log.message, policy_cb_data)) { + add_log_tombstone(&arg, refname, log.update_index); + } + } + reftable_log_record_clear(&log); + reftable_iterator_destroy(&it); + err = reftable_stack_add(refs->stack, &write_reflog_expiry_table, &arg); + clear_log_tombstones(&arg); + return err; +} + +static int reftable_read_raw_ref(struct ref_store *ref_store, + const char *refname, struct object_id *oid, + struct strbuf *referent, unsigned int *type) +{ + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + struct reftable_ref_record ref = { NULL }; + int err = 0; + if (refs->err < 0) { + return refs->err; + } + + err = reftable_stack_read_ref(refs->stack, refname, &ref); + if (err) { + goto exit; + } + if (ref.target != NULL) { + /* XXX recurse? */ + strbuf_reset(referent); + strbuf_addstr(referent, ref.target); + *type |= REF_ISSYMREF; + } else { + hashcpy(oid->hash, ref.value); + } +exit: + reftable_ref_record_clear(&ref); + return err; +} + +struct ref_storage_be refs_be_reftable = { + &refs_be_files, + "reftable", + git_reftable_ref_store_create, + reftable_init_db, + reftable_transaction_prepare, + reftable_transaction_finish, + reftable_transaction_abort, + reftable_transaction_commit, + + reftable_pack_refs, + reftable_create_symref, + reftable_delete_refs, + reftable_rename_ref, + reftable_copy_ref, + + reftable_ref_iterator_begin, + reftable_read_raw_ref, + + reftable_reflog_iterator_begin, + reftable_for_each_reflog_ent_newest_first, + reftable_for_each_reflog_ent_oldest_first, + reftable_reflog_exists, + reftable_create_reflog, + reftable_delete_reflog, + reftable_reflog_expire +}; diff --git a/repository.c b/repository.c index 6f7f6f002b1..087760bc184 100644 --- a/repository.c +++ b/repository.c @@ -178,6 +178,8 @@ int repo_init(struct repository *repo, if (worktree) repo_set_worktree(repo, worktree); + repo->ref_storage_format = xstrdup_or_null(format.ref_storage); + clear_repository_format(&format); return 0; diff --git a/repository.h b/repository.h index 040057dea6f..198d4aa0907 100644 --- a/repository.h +++ b/repository.h @@ -70,6 +70,9 @@ struct repository { /* The store in which the refs are held. */ struct ref_store *refs; + /* The format to use for the ref database. */ + char *ref_storage_format; + /* * Contains path to often used file names. */ diff --git a/setup.c b/setup.c index 65fe5ecefbe..2ef970f9f88 100644 --- a/setup.c +++ b/setup.c @@ -468,9 +468,11 @@ static int check_repo_format(const char *var, const char *value, void *vdata) if (!value) return config_error_nonbool(var); data->partial_clone = xstrdup(value); - } else if (!strcmp(ext, "worktreeconfig")) + } else if (!strcmp(ext, "worktreeconfig")) { data->worktree_config = git_config_bool(var, value); - else + } else if (!strcmp(ext, "refstorage")) { + data->ref_storage = xstrdup(value); + } else string_list_append(&data->unknown_extensions, ext); } @@ -559,6 +561,7 @@ void clear_repository_format(struct repository_format *format) string_list_clear(&format->unknown_extensions, 0); free(format->work_tree); free(format->partial_clone); + free(format->ref_storage); init_repository_format(format); } @@ -1204,8 +1207,11 @@ const char *setup_git_directory_gently(int *nongit_ok) gitdir = DEFAULT_GIT_DIR_ENVIRONMENT; setup_git_env(gitdir); } - if (startup_info->have_repository) + if (startup_info->have_repository) { repo_set_hash_algo(the_repository, repo_fmt.hash_algo); + the_repository->ref_storage_format = + xstrdup_or_null(repo_fmt.ref_storage); + } } strbuf_release(&dir); diff --git a/t/t0031-reftable.sh b/t/t0031-reftable.sh new file mode 100755 index 00000000000..4da1bd0846f --- /dev/null +++ b/t/t0031-reftable.sh @@ -0,0 +1,35 @@ +#!/bin/sh +# +# Copyright (c) 2020 Google LLC +# + +test_description='reftable basics' + +. ./test-lib.sh + +# XXX - fix GC +test_expect_success 'basic operation of reftable storage' ' + rm -rf .git && + git init --ref-storage=reftable && + mv .git/hooks .git/hooks-disabled && + test_commit file && + test_write_lines refs/heads/master refs/tags/file >expect && + git show-ref && + git show-ref | cut -f2 -d" " > actual && + test_cmp actual expect && + for count in $(test_seq 1 10) + do + test_commit "number $count" file.t $count number-$count || + return 1 + done && +(true || (test_pause && + git gc && + ls -1 .git/reftable >table-files && + test_line_count = 2 table-files && + git reflog refs/heads/master >output && + test_line_count = 11 output && + grep "commit (initial): first post" output && + grep "commit: number 10" output )) +' + +test_done -- gitgitgadget
