[PATCH v5 13/15] Reftable support for git-core
- From
Han-Wen Nienhuys via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Mar 12, 2021, 20:19 UTC
- Message-ID
- <bdb19af22cc7c4f3383f03f42cb4906c3ec5c5f3.1615580397.git.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.847.v5.git.git.1615580397.gitgitgadget@gmail.com>
From: Han-Wen Nienhuys <hanwen@google.com>
For background, see the previous commit introducing the library.
This introduces the file refs/reftable-backend.c containing a reftable-powered ref storage backend.
It can be activated by passing --ref-storage=reftable to "git init", or setting GIT_TEST_REFTABLE in the environment.
Example use: see t/t0031-reftable.sh
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de> Helped-by: Junio Hamano <gitster@pobox.com> Co-authored-by: Jeff King <peff@peff.net> --- Documentation/config/extensions.txt | 9 + .../technical/repository-version.txt | 7 + Makefile | 4 + builtin/clone.c | 5 +- builtin/init-db.c | 55 +- builtin/worktree.c | 27 +- cache.h | 8 +- config.mak.uname | 2 +- contrib/buildsystems/Generators/Vcxproj.pm | 11 +- refs.c | 27 +- refs.h | 3 + refs/refs-internal.h | 1 + refs/reftable-backend.c | 1446 +++++++++++++++++ repository.c | 2 + repository.h | 3 + setup.c | 9 +- t/t0031-reftable.sh | 203 +++ t/t1409-avoid-packing-refs.sh | 6 + t/t1450-fsck.sh | 6 + t/t3210-pack-refs.sh | 6 + t/test-lib.sh | 5 + 21 files changed, 1812 insertions(+), 33 deletions(-) create mode 100644 refs/reftable-backend.c create mode 100755 t/t0031-reftable.sh
diff --git a/Documentation/config/extensions.txt b/Documentation/config/extensions.txt index 4e23d73cdcad..82c5940f1434 100644 --- a/Documentation/config/extensions.txt +++ b/Documentation/config/extensions.txt @@ -6,3 +6,12 @@ extensions.objectFormat:: Note that this setting should only be set by linkgit:git-init[1] or linkgit:git-clone[1]. Trying to change it after initialization will not work and will produce hard-to-diagnose issues. ++ +extensions.refStorage:: + Specify the ref storage mechanism to use. The acceptable values are `files` and + `reftable`. If not specified, `files` is assumed. It is an error to specify + this key unless `core.repositoryFormatVersion` is 1. ++ +Note that this setting should only be set by linkgit:git-init[1] or +linkgit:git-clone[1]. Trying to change it after initialization will not +work and will produce hard-to-diagnose issues. diff --git a/Documentation/technical/repository-version.txt b/Documentation/technical/repository-version.txt index 7844ef30ffde..725762358333 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 a00cc17ec781..90c204501739 100644 --- a/Makefile +++ b/Makefile @@ -967,6 +967,7 @@ LIB_OBJS += reflog-walk.o LIB_OBJS += refs.o LIB_OBJS += refs/debug.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 @@ -2401,8 +2402,11 @@ REFTABLE_OBJS += reftable/zlib-compat.o REFTABLE_TEST_OBJS += reftable/basics_test.o REFTABLE_TEST_OBJS += reftable/block_test.o +REFTABLE_TEST_OBJS += reftable/merged_test.o REFTABLE_TEST_OBJS += reftable/record_test.o +REFTABLE_TEST_OBJS += reftable/refname_test.o REFTABLE_TEST_OBJS += reftable/reftable_test.o +REFTABLE_TEST_OBJS += reftable/stack_test.o REFTABLE_TEST_OBJS += reftable/test_framework.o REFTABLE_TEST_OBJS += reftable/tree_test.o diff --git a/builtin/clone.c b/builtin/clone.c index 51e844a2de0a..6eee72d1ffe5 100644 --- a/builtin/clone.c +++ b/builtin/clone.c @@ -1139,7 +1139,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix) } init_db(git_dir, real_git_dir, option_template, GIT_HASH_UNKNOWN, NULL, - INIT_DB_QUIET); + default_ref_storage(), INIT_DB_QUIET); if (real_git_dir) git_dir = real_git_dir; @@ -1277,7 +1277,8 @@ int cmd_clone(int argc, const char **argv, const char *prefix) * Now that we know what algorithm the remote side is using, * let's set ours to the same thing. */ - initialize_repository_version(hash_algo, 1); + initialize_repository_version(hash_algo, 1, + default_ref_storage()); repo_set_hash_algo(the_repository, hash_algo); mapped_refs = wanted_peer_refs(refs, &remote->fetch); diff --git a/builtin/init-db.c b/builtin/init-db.c index 7766661a4755..c4fb62056344 100644 --- a/builtin/init-db.c +++ b/builtin/init-db.c @@ -179,12 +179,14 @@ static int needs_work_tree_config(const char *git_dir, const char *work_tree) return 1; } -void initialize_repository_version(int hash_algo, int reinit) +void initialize_repository_version(int hash_algo, int reinit, + const char *ref_storage_format) { char repo_version_string[10]; int repo_version = GIT_REPO_VERSION; - 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 +240,7 @@ 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 +250,24 @@ 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); + + /* + * refs/heads is a file when using reftable. We can't reinitialize with + * a reftable because it will overwrite HEAD + */ + if (reinit && (!strcmp(fmt->ref_storage, "reftable")) == + is_directory(git_path_buf(&buf, "refs/heads"))) { + die("cannot switch ref storage format."); + } + /* * We need to create a "refs" dir in any case so that older * versions of git can tell that this is a repository. @@ -261,9 +282,6 @@ static int create_default_files(const char *template_path, * Point the HEAD symref to the initial branch with if HEAD does * not yet exist. */ - path = git_path_buf(&buf, "HEAD"); - reinit = (!access(path, R_OK) - || readlink(path, junk, sizeof(junk)-1) != -1); if (!reinit) { char *ref; @@ -280,7 +298,7 @@ static int create_default_files(const char *template_path, free(ref); } - initialize_repository_version(fmt->hash_algo, 0); + initialize_repository_version(fmt->hash_algo, 0, fmt->ref_storage); /* Check filemode trustability */ path = git_path_buf(&buf, "config"); @@ -396,7 +414,7 @@ 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, const char *initial_branch, - unsigned int flags) + const char *ref_storage_format, unsigned int flags) { int reinit; int exist_ok = flags & INIT_DB_EXIST_OK; @@ -435,6 +453,7 @@ 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); @@ -489,6 +508,9 @@ int init_db(const char *git_dir, const char *real_git_dir, git_config_set("receive.denyNonFastforwards", "true"); } + if (!strcmp(ref_storage_format, "reftable")) + git_config_set("extensions.refStorage", ref_storage_format); + if (!(flags & INIT_DB_QUIET)) { int len = strlen(git_dir); @@ -562,6 +584,7 @@ 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; @@ -570,15 +593,18 @@ int cmd_init_db(int argc, const char **argv, const char *prefix) const char *initial_branch = 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('b', "initial-branch", &initial_branch, N_("name"), @@ -719,10 +745,11 @@ 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, - initial_branch, flags); + initial_branch, ref_storage_format, flags); } diff --git a/builtin/worktree.c b/builtin/worktree.c index 1cd5c2016e3f..a5d044e116b1 100644 --- a/builtin/worktree.c +++ b/builtin/worktree.c @@ -13,6 +13,7 @@ #include "utf8.h" #include "worktree.h" #include "quote.h" +#include "../refs/refs-internal.h" static const char * const worktree_usage[] = { N_("git worktree add [<options>] <path> [<commit-ish>]"), @@ -330,9 +331,29 @@ static int add_worktree(const char *path, const char *refname, * worktree. */ strbuf_reset(&sb); - strbuf_addf(&sb, "%s/HEAD", sb_repo.buf); - write_file(sb.buf, "%s", oid_to_hex(&null_oid)); - strbuf_reset(&sb); + if (get_main_ref_store(the_repository)->be == &refs_be_reftable) { + /* XXX this is cut & paste from reftable_init_db. */ + strbuf_addf(&sb, "%s/HEAD", sb_repo.buf); + write_file(sb.buf, "%s", "ref: refs/heads/.invalid\n"); + strbuf_reset(&sb); + + strbuf_addf(&sb, "%s/refs", sb_repo.buf); + safe_create_dir(sb.buf, 1); + strbuf_reset(&sb); + + strbuf_addf(&sb, "%s/refs/heads", sb_repo.buf); + write_file(sb.buf, "this repository uses the reftable format"); + strbuf_reset(&sb); + + strbuf_addf(&sb, "%s/reftable", sb_repo.buf); + safe_create_dir(sb.buf, 1); + strbuf_reset(&sb); + } else { + strbuf_addf(&sb, "%s/HEAD", sb_repo.buf); + write_file(sb.buf, "%s", oid_to_hex(&null_oid)); + strbuf_reset(&sb); + } + strbuf_addf(&sb, "%s/commondir", sb_repo.buf); write_file(sb.buf, "../.."); diff --git a/cache.h b/cache.h index 6fda8091f11d..be8fa1ddd6fc 100644 --- a/cache.h +++ b/cache.h @@ -629,9 +629,10 @@ int path_inside_repo(const char *prefix, const char *path); #define INIT_DB_EXIST_OK 0x0002 int init_db(const char *git_dir, const char *real_git_dir, - const char *template_dir, int hash_algo, - const char *initial_branch, unsigned int flags); -void initialize_repository_version(int hash_algo, int reinit); + const char *template_dir, int hash_algo, const char *initial_branch, + const char *ref_storage_format, unsigned int flags); +void initialize_repository_version(int hash_algo, int reinit, + const char *ref_storage_format); void sanitize_stdfds(void); int daemonize(void); @@ -1045,6 +1046,7 @@ struct repository_format { int is_bare; int hash_algo; char *work_tree; + char *ref_storage; struct string_list unknown_extensions; struct string_list v1_only_extensions; }; diff --git a/config.mak.uname b/config.mak.uname index d204c20a6469..6cba285e8fa3 100644 --- a/config.mak.uname +++ b/config.mak.uname @@ -699,7 +699,7 @@ vcxproj: # Make .vcxproj files and add them unset QUIET_GEN QUIET_BUILT_IN; \ perl contrib/buildsystems/generate -g Vcxproj - git add -f git.sln {*,*/lib,t/helper/*}/*.vcxproj + git add -f git.sln {*,*/lib,*/libreftable,t/helper/*}/*.vcxproj # Generate the LinkOrCopyBuiltins.targets and LinkOrCopyRemoteHttp.targets file (echo '<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">' && \ diff --git a/contrib/buildsystems/Generators/Vcxproj.pm b/contrib/buildsystems/Generators/Vcxproj.pm index d2584450ba17..1a25789d2851 100644 --- a/contrib/buildsystems/Generators/Vcxproj.pm +++ b/contrib/buildsystems/Generators/Vcxproj.pm @@ -77,7 +77,7 @@ sub createProject { my $libs_release = "\n "; my $libs_debug = "\n "; if (!$static_library) { - $libs_release = join(";", sort(grep /^(?!libgit\.lib|xdiff\/lib\.lib|vcs-svn\/lib\.lib)/, @{$$build_structure{"$prefix${name}_LIBS"}})); + $libs_release = join(";", sort(grep /^(?!libgit\.lib|xdiff\/lib\.lib|vcs-svn\/lib\.lib|reftable\/libreftable\.lib)/, @{$$build_structure{"$prefix${name}_LIBS"}})); $libs_debug = $libs_release; $libs_debug =~ s/zlib\.lib/zlibd\.lib/g; $libs_debug =~ s/libexpat\.lib/libexpatd\.lib/g; @@ -232,6 +232,7 @@ sub createProject { EOM if (!$static_library || $target =~ 'vcs-svn' || $target =~ 'xdiff') { my $uuid_libgit = $$build_structure{"LIBS_libgit_GUID"}; + my $uuid_libreftable = $$build_structure{"LIBS_reftable/libreftable_GUID"}; my $uuid_xdiff_lib = $$build_structure{"LIBS_xdiff/lib_GUID"}; print F << "EOM"; @@ -241,6 +242,14 @@ sub createProject { <ReferenceOutputAssembly>false</ReferenceOutputAssembly> </ProjectReference> EOM + if (!($name =~ /xdiff|libreftable/)) { + print F << "EOM"; + <ProjectReference Include="$cdup\\reftable\\libreftable\\libreftable.vcxproj"> + <Project>$uuid_libreftable</Project> + <ReferenceOutputAssembly>false</ReferenceOutputAssembly> + </ProjectReference> +EOM + } if (!($name =~ 'xdiff')) { print F << "EOM"; <ProjectReference Include="$cdup\\xdiff\\lib\\xdiff_lib.vcxproj"> diff --git a/refs.c b/refs.c index a665ed5e10ac..bc27a5e1b282 100644 --- a/refs.c +++ b/refs.c @@ -19,10 +19,16 @@ #include "repository.h" #include "sigchain.h" +const char *default_ref_storage(void) +{ + const char *test = getenv("GIT_TEST_REFTABLE"); + return test ? "reftable" : "files"; +} + /* * 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) { @@ -1875,13 +1881,13 @@ 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); @@ -1897,7 +1903,11 @@ 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_private = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS); + r->refs_private = ref_store_init(r->gitdir, + r->ref_storage_format ? + r->ref_storage_format : + default_ref_storage(), + REF_STORE_ALL_CAPS); r->refs_private = maybe_debug_wrap_ref_store(r->gitdir, r->refs_private); return r->refs_private; } @@ -1953,7 +1963,7 @@ 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(), REF_STORE_READ | REF_STORE_ODB); register_ref_store_map(&submodule_ref_stores, "submodule", refs, submodule); @@ -1967,6 +1977,7 @@ 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(); struct ref_store *refs; const char *id; @@ -1980,9 +1991,9 @@ 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 48970dfc7e0f..5a6d4ca9fa8d 100644 --- a/refs.h +++ b/refs.h @@ -11,6 +11,9 @@ struct string_list; struct string_list_item; struct worktree; +/* Returns the ref storage backend to use by default. */ +const char *default_ref_storage(void); + /* * Resolve a reference, recursively following symbolic refererences. * diff --git a/refs/refs-internal.h b/refs/refs-internal.h index 467f4b3c936d..28166bf1f82b 100644 --- a/refs/refs-internal.h +++ b/refs/refs-internal.h @@ -669,6 +669,7 @@ 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 000000000000..f1f3e60a9c7c --- /dev/null +++ b/refs/reftable-backend.c @@ -0,0 +1,1446 @@ +#include "../cache.h" +#include "../chdir-notify.h" +#include "../config.h" +#include "../iterator.h" +#include "../lockfile.h" +#include "../refs.h" +#include "../reftable/reftable-stack.h" +#include "../reftable/reftable-record.h" +#include "../reftable/reftable-error.h" +#include "../reftable/reftable-blocksource.h" +#include "../reftable/reftable-reader.h" +#include "../reftable/reftable-iterator.h" +#include "../reftable/reftable-merged.h" +#include "../reftable/reftable-generic.h" +#include "../worktree.h" +#include "refs-internal.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 *repo_dir; + + char *reftable_dir; + char *worktree_reftable_dir; + + struct reftable_stack *main_stack; + struct reftable_stack *worktree_stack; +}; + +static struct reftable_stack *stack_for(struct git_reftable_ref_store *store, + const char *refname) +{ + if (store->worktree_stack == NULL) + return store->main_stack; + + switch (ref_type(refname)) { + case REF_TYPE_PER_WORKTREE: + case REF_TYPE_PSEUDOREF: + case REF_TYPE_OTHER_PSEUDOREF: + return store->worktree_stack; + default: + case REF_TYPE_MAIN_PSEUDOREF: + case REF_TYPE_NORMAL: + return store->main_stack; + } +} + +static int git_reftable_read_raw_ref(struct ref_store *ref_store, + const char *refname, struct object_id *oid, + struct strbuf *referent, + unsigned int *type); + +static void clear_reftable_log_record(struct reftable_log_record *log) +{ + log->refname = NULL; + switch (log->value_type) { + case REFTABLE_LOG_UPDATE: + log->update.old_hash = NULL; + log->update.new_hash = NULL; + log->update.message = NULL; + break; + case REFTABLE_LOG_DELETION: + break; + } + reftable_log_record_release(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_release(log); + log->value_type = REFTABLE_LOG_UPDATE; + log->update.name = + xstrndup(split.name_begin, split.name_end - split.name_begin); + log->update.email = + xstrndup(split.mail_begin, split.mail_end - split.mail_begin); + log->update.time = atol(split.date_begin); + if (*split.tz_begin == '-') { + sign = -1; + split.tz_begin++; + } + if (*split.tz_begin == '+') { + sign = 1; + split.tz_begin++; + } + + log->update.tz_offset = sign * atoi(split.tz_begin); +} + +static int has_suffix(struct strbuf *b, const char *suffix) +{ + size_t len = strlen(suffix); + + if (len > b->len) { + return 0; + } + + return 0 == strncmp(b->buf + b->len - len, suffix, len); +} + +/* trims the last path component of b. Returns -1 if it is not + * present, or 0 on success + */ +static int trim_component(struct strbuf *b) +{ + char *last; + last = strrchr(b->buf, '/'); + if (!last) + return -1; + strbuf_setlen(b, last - b->buf); + return 0; +} + +/* Returns whether `b` is a worktree path, trimming it to the gitdir + */ +static int is_worktree(struct strbuf *b) +{ + if (trim_component(b) < 0) { + return 0; + } + if (!has_suffix(b, "/worktrees")) { + return 0; + } + trim_component(b); + return 1; +} + +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; + const char *gitdir = path; + struct strbuf wt_buf = STRBUF_INIT; + int wt = 0; + + strbuf_addstr(&wt_buf, path); + + /* this is clumsy, but the official worktree functions (eg. + * get_worktrees()) function will try to initialize a ref storage + * backend, leading to infinite recursion. */ + wt = is_worktree(&wt_buf); + if (wt) { + gitdir = wt_buf.buf; + } + + base_ref_store_init(ref_store, &refs_be_reftable); + ref_store->gitdir = xstrdup(gitdir); + refs->store_flags = store_flags; + strbuf_addf(&sb, "%s/reftable", gitdir); + refs->reftable_dir = xstrdup(sb.buf); + strbuf_reset(&sb); + + refs->err = + reftable_new_stack(&refs->main_stack, refs->reftable_dir, cfg); + assert(refs->err != REFTABLE_API_ERROR); + + if (refs->err == 0 && wt) { + strbuf_addf(&sb, "%s/reftable", path); + refs->worktree_reftable_dir = xstrdup(sb.buf); + + refs->err = reftable_new_stack(&refs->worktree_stack, + refs->worktree_reftable_dir, + cfg); + assert(refs->err != REFTABLE_API_ERROR); + } + + strbuf_release(&sb); + strbuf_release(&wt_buf); + return ref_store; +} + +static int git_reftable_init_db(struct ref_store *ref_store, struct strbuf *err) +{ + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + struct strbuf sb = STRBUF_INIT; + + safe_create_dir(refs->reftable_dir, 1); + assert(refs->worktree_reftable_dir == NULL); + + strbuf_addf(&sb, "%s/HEAD", refs->base.gitdir); + write_file(sb.buf, "ref: refs/heads/.invalid"); + strbuf_reset(&sb); + + strbuf_addf(&sb, "%s/refs", refs->base.gitdir); + safe_create_dir(sb.buf, 1); + strbuf_reset(&sb); + + strbuf_addf(&sb, "%s/refs/heads", refs->base.gitdir); + write_file(sb.buf, "this repository uses the reftable format"); + + 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; + + /* In case we must iterate over 2 stacks, this is non-null. */ + struct reftable_merged_table *merged; + 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; + } + + if (ref_type(ri->ref.refname) == REF_TYPE_PSEUDOREF) { + /* + pseudorefs, eg. HEAD, FETCH_HEAD should not be + produced, by default. + */ + continue; + } + ri->base.refname = ri->ref.refname; + if (ri->prefix != NULL && + strncmp(ri->prefix, ri->ref.refname, 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; + switch (ri->ref.value_type) { + case REFTABLE_REF_VAL1: + hashcpy(ri->oid.hash, ri->ref.value.val1); + break; + case REFTABLE_REF_VAL2: + hashcpy(ri->oid.hash, ri->ref.value.val2.value); + break; + case REFTABLE_REF_SYMREF: { + int out_flags = 0; + const char *resolved = refs_resolve_ref_unsafe( + ri->ref_store, ri->ref.refname, + 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; + } + break; + } + default: + abort(); + } + + 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.value_type == REFTABLE_REF_VAL2) { + hashcpy(peeled->hash, ri->ref.value.val2.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_release(&ri->ref); + reftable_iterator_destroy(&ri->iter); + if (ri->merged) { + reftable_merged_table_free(ri->merged); + } + 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 * +git_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)); + + if (refs->err < 0) { + ri->err = refs->err; + } else if (refs->worktree_stack == NULL) { + struct reftable_merged_table *mt = + reftable_stack_merged_table(refs->main_stack); + ri->err = reftable_merged_table_seek_ref(mt, &ri->iter, prefix); + } else { + struct reftable_merged_table *mt1 = + reftable_stack_merged_table(refs->main_stack); + struct reftable_merged_table *mt2 = + reftable_stack_merged_table(refs->worktree_stack); + struct reftable_table *tabs = + xcalloc(2, sizeof(struct reftable_table)); + reftable_table_from_merged_table(&tabs[0], mt1); + reftable_table_from_merged_table(&tabs[1], mt2); + ri->err = reftable_new_merged_table(&ri->merged, tabs, 2, + the_hash_algo->format_id); + if (ri->err == 0) + ri->err = reftable_merged_table_seek_ref( + ri->merged, &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 fixup_symrefs(struct ref_store *ref_store, + struct ref_transaction *transaction) +{ + struct strbuf referent = STRBUF_INIT; + int i = 0; + int err = 0; + + for (i = 0; i < transaction->nr; i++) { + struct ref_update *update = transaction->updates[i]; + struct object_id old_oid; + + err = git_reftable_read_raw_ref(ref_store, update->refname, + &old_oid, &referent, + /* mutate input, like + files-backend.c */ + &update->type); + if (err < 0 && errno == ENOENT && + is_null_oid(&update->old_oid)) { + err = 0; + } + if (err < 0) + goto done; + + if (!(update->type & REF_ISSYMREF)) + continue; + + if (update->flags & REF_NO_DEREF) { + /* what should happen here? See files-backend.c + * lock_ref_for_update. */ + } else { + /* + If we are updating a symref (eg. HEAD), we should also + update the branch that the symref points to. + + This is generic functionality, and would be better + done in refs.c, but the current implementation is + intertwined with the locking in files-backend.c. + */ + int new_flags = update->flags; + struct ref_update *new_update = NULL; + + /* if this is an update for HEAD, should also record a + log entry for HEAD? See files-backend.c, + split_head_update() + */ + new_update = ref_transaction_add_update( + transaction, referent.buf, new_flags, + &update->new_oid, &update->old_oid, + update->msg); + new_update->parent_update = update; + + /* files-backend sets REF_LOG_ONLY here. */ + update->flags |= REF_NO_DEREF | REF_LOG_ONLY; + update->flags &= ~REF_HAVE_OLD; + } + } + +done: + assert(err != REFTABLE_API_ERROR); + strbuf_release(&referent); + return err; +} + +static int git_reftable_transaction_prepare(struct ref_store *ref_store, + struct ref_transaction *transaction, + struct strbuf *errbuf) +{ + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + struct reftable_addition *add = NULL; + struct reftable_stack *stack = + transaction->nr ? + stack_for(refs, transaction->updates[0]->refname) : + refs->main_stack; + int err = refs->err; + if (err < 0) { + goto done; + } + + err = reftable_stack_reload(stack); + if (err) { + goto done; + } + + err = reftable_stack_new_addition(&add, stack); + if (err) { + goto done; + } + + err = fixup_symrefs(ref_store, transaction); + if (err) { + goto done; + } + + transaction->backend_data = add; + transaction->state = REF_TRANSACTION_PREPARED; + +done: + assert(err != REFTABLE_API_ERROR); + if (err < 0) { + transaction->state = REF_TRANSACTION_CLOSED; + strbuf_addf(errbuf, "reftable: transaction prepare: %s", + reftable_error_str(err)); + } + + return err; +} + +static int git_reftable_transaction_abort(struct ref_store *ref_store, + struct ref_transaction *transaction, + struct strbuf *err) +{ + struct reftable_addition *add = + (struct reftable_addition *)transaction->backend_data; + reftable_addition_destroy(add); + transaction->backend_data = NULL; + 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 REFTABLE_LOCK_ERROR; + } + + if (resolved != NULL && !oideq(&out_oid, want_oid)) { + return REFTABLE_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; + struct reftable_stack *stack = + stack_for(refs, transaction->updates[0]->refname); + uint64_t ts = reftable_stack_next_update_index(stack); + int err = 0; + int i = 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 (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->update_index = ts; + log->value_type = REFTABLE_LOG_UPDATE; + log->refname = (char *)u->refname; + log->update.old_hash = u->old_oid.hash; + log->update.new_hash = u->new_oid.hash; + log->update.message = u->msg; + + if (u->flags & REF_LOG_ONLY) { + continue; + } + + if (u->flags & REF_HAVE_NEW) { + struct reftable_ref_record ref = { NULL }; + struct object_id peeled; + + int peel_error = peel_object(&u->new_oid, &peeled); + ref.refname = (char *)u->refname; + ref.update_index = ts; + + if (!peel_error) { + ref.value_type = REFTABLE_REF_VAL2; + ref.value.val2.target_value = peeled.hash; + ref.value.val2.value = u->new_oid.hash; + } else if (!is_null_oid(&u->new_oid)) { + ref.value_type = REFTABLE_REF_VAL1; + ref.value.val1 = u->new_oid.hash; + } + + err = reftable_writer_add_ref(writer, &ref); + if (err < 0) { + goto done; + } + } + } + + for (i = 0; i < transaction->nr; i++) { + err = reftable_writer_add_log(writer, &logs[i]); + clear_reftable_log_record(&logs[i]); + if (err < 0) { + goto done; + } + } + +done: + assert(err != REFTABLE_API_ERROR); + free(logs); + free(sorted); + return err; +} + +static int git_reftable_transaction_finish(struct ref_store *ref_store, + struct ref_transaction *transaction, + struct strbuf *errmsg) +{ + struct reftable_addition *add = + (struct reftable_addition *)transaction->backend_data; + int err = 0; + int i; + + for (i = 0; i < transaction->nr; i++) { + struct ref_update *u = transaction->updates[i]; + if (u->flags & REF_HAVE_OLD) { + err = reftable_check_old_oid(transaction->ref_store, + u->refname, &u->old_oid); + if (err < 0) { + goto done; + } + } + } + if (transaction->nr) { + err = reftable_addition_add(add, &write_transaction_table, + transaction); + if (err < 0) { + goto done; + } + } + + err = reftable_addition_commit(add); + +done: + assert(err != REFTABLE_API_ERROR); + reftable_addition_destroy(add); + transaction->state = REF_TRANSACTION_CLOSED; + transaction->backend_data = NULL; + if (err) { + strbuf_addf(errmsg, "reftable: transaction failure: %s", + reftable_error_str(err)); + return -1; + } + return err; +} + +static int +git_reftable_transaction_initial_commit(struct ref_store *ref_store, + struct ref_transaction *transaction, + struct strbuf *errmsg) +{ + int err = git_reftable_transaction_prepare(ref_store, transaction, + errmsg); + if (err) + return err; + + return git_reftable_transaction_finish(ref_store, transaction, errmsg); +} + +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; + int i = 0; + + reftable_writer_set_limits(writer, ts, ts); + for (i = 0; i < arg->refnames->nr; i++) { + struct reftable_ref_record ref = { + .refname = (char *)arg->refnames->items[i].string, + .value_type = REFTABLE_REF_DELETION, + .update_index = ts, + }; + err = reftable_writer_add_ref(writer, &ref); + if (err < 0) { + return err; + } + } + + for (i = 0; i < arg->refnames->nr; i++) { + struct reftable_log_record log = { + .update_index = ts, + }; + struct reftable_ref_record current = { NULL }; + fill_reftable_log_record(&log); + log.update_index = ts; + log.refname = (char *)arg->refnames->items[i].string; + + log.update.message = xstrdup(arg->logmsg); + log.update.new_hash = NULL; + log.update.old_hash = NULL; + if (reftable_stack_read_ref(arg->stack, log.refname, + ¤t) == 0) { + log.update.old_hash = + reftable_ref_record_val1(¤t); + } + err = reftable_writer_add_log(writer, &log); + log.update.old_hash = NULL; + reftable_ref_record_release(¤t); + + clear_reftable_log_record(&log); + if (err < 0) { + return err; + } + } + return 0; +} + +static int git_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 reftable_stack *stack = + stack_for(refs, refnames->items[0].string); + struct write_delete_refs_arg arg = { + .stack = stack, + .refnames = refnames, + .logmsg = msg, + .flags = flags, + }; + int err = refs->err; + if (err < 0) { + goto done; + } + + string_list_sort(refnames); + err = reftable_stack_reload(stack); + if (err) { + goto done; + } + err = reftable_stack_add(stack, &write_delete_refs_table, &arg); +done: + assert(err != REFTABLE_API_ERROR); + return err; +} + +static int git_reftable_pack_refs(struct ref_store *ref_store, + unsigned int flags) +{ + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + int err = refs->err; + if (err < 0) { + return err; + } + err = reftable_stack_compact_all(refs->main_stack, NULL); + if (err == 0 && refs->worktree_stack != NULL) + err = reftable_stack_compact_all(refs->worktree_stack, NULL); + return err; +} + +struct write_create_symref_arg { + struct git_reftable_ref_store *refs; + struct reftable_stack *stack; + 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->stack); + int err = 0; + + struct reftable_ref_record ref = { + .refname = (char *)create->refname, + .value_type = REFTABLE_REF_SYMREF, + .value.symref = (char *)create->target, + .update_index = ts, + }; + reftable_writer_set_limits(writer, ts, ts); + err = reftable_writer_add_ref(writer, &ref); + if (err == 0) { + struct reftable_log_record log = { NULL }; + struct object_id new_oid; + struct object_id old_oid; + + fill_reftable_log_record(&log); + log.refname = (char *)create->refname; + log.update_index = ts; + log.update.message = (char *)create->logmsg; + if (refs_resolve_ref_unsafe( + (struct ref_store *)create->refs, create->refname, + RESOLVE_REF_READING, &old_oid, NULL) != NULL) { + log.update.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.update.new_hash = new_oid.hash; + } + + if (log.update.old_hash != NULL || + log.update.new_hash != NULL) { + err = reftable_writer_add_log(writer, &log); + } + log.refname = NULL; + log.update.message = NULL; + log.update.old_hash = NULL; + log.update.new_hash = NULL; + clear_reftable_log_record(&log); + } + return err; +} + +static int git_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 reftable_stack *stack = stack_for(refs, refname); + struct write_create_symref_arg arg = { .refs = refs, + .stack = stack, + .refname = refname, + .target = target, + .logmsg = logmsg }; + int err = refs->err; + if (err < 0) { + goto done; + } + err = reftable_stack_reload(stack); + if (err) { + goto done; + } + err = reftable_stack_add(stack, &write_create_symref_table, &arg); +done: + assert(err != REFTABLE_API_ERROR); + return err; +} + +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 done; + } + + /* XXX do ref renames overwrite the target? */ + if (reftable_stack_read_ref(arg->stack, arg->newname, &ref) == 0) { + goto done; + } + + reftable_writer_set_limits(writer, ts, ts); + + { + struct reftable_ref_record todo[2] = { + { + .refname = (char *)arg->oldname, + .update_index = ts, + .value_type = REFTABLE_REF_DELETION, + }, + ref, + }; + todo[1].update_index = ts; + free(todo[1].refname); + todo[1].refname = strdup(arg->newname); + + err = reftable_writer_add_refs(writer, todo, 2); + if (err < 0) { + goto done; + } + } + + if (reftable_ref_record_val1(&ref)) { + uint8_t *val1 = reftable_ref_record_val1(&ref); + struct reftable_log_record todo[2] = { { NULL } }; + fill_reftable_log_record(&todo[0]); + fill_reftable_log_record(&todo[1]); + + todo[0].refname = (char *)arg->oldname; + todo[0].update_index = ts; + todo[0].update.message = (char *)arg->logmsg; + todo[0].update.old_hash = val1; + todo[0].update.new_hash = NULL; + + todo[1].refname = (char *)arg->newname; + todo[1].update_index = ts; + todo[1].update.old_hash = NULL; + todo[1].update.new_hash = val1; + todo[1].update.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 done; + } + + } else { + /* XXX symrefs? */ + } + +done: + assert(err != REFTABLE_API_ERROR); + reftable_ref_record_release(&ref); + return err; +} + +static int git_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 reftable_stack *stack = stack_for(refs, newrefname); + struct write_rename_arg arg = { + .stack = stack, + .oldname = oldrefname, + .newname = newrefname, + .logmsg = logmsg, + }; + int err = refs->err; + if (err < 0) { + goto done; + } + err = reftable_stack_reload(stack); + if (err) { + goto done; + } + + err = reftable_stack_add(stack, &write_rename_table, &arg); +done: + assert(err != REFTABLE_API_ERROR); + return err; +} + +static int git_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 git_reftable_reflog_ref_iterator { + struct ref_iterator base; + struct reftable_iterator iter; + struct reftable_log_record log; + struct object_id oid; + + /* Used when iterating over worktree & main */ + struct reftable_merged_table *merged; + char *last_name; +}; + +static int +git_reftable_reflog_ref_iterator_advance(struct ref_iterator *ref_iterator) +{ + struct git_reftable_reflog_ref_iterator *ri = + (struct git_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; + } + + ri->base.refname = ri->log.refname; + if (ri->last_name != NULL && + !strcmp(ri->log.refname, 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.refname); + hashcpy(ri->oid.hash, ri->log.update.new_hash); + return ITER_OK; + } +} + +static int +git_reftable_reflog_ref_iterator_peel(struct ref_iterator *ref_iterator, + struct object_id *peeled) +{ + BUG("not supported."); + return -1; +} + +static int +git_reftable_reflog_ref_iterator_abort(struct ref_iterator *ref_iterator) +{ + struct git_reftable_reflog_ref_iterator *ri = + (struct git_reftable_reflog_ref_iterator *)ref_iterator; + reftable_log_record_release(&ri->log); + reftable_iterator_destroy(&ri->iter); + if (ri->merged) + reftable_merged_table_free(ri->merged); + return 0; +} + +static struct ref_iterator_vtable git_reftable_reflog_ref_iterator_vtable = { + git_reftable_reflog_ref_iterator_advance, + git_reftable_reflog_ref_iterator_peel, + git_reftable_reflog_ref_iterator_abort +}; + +static struct ref_iterator * +git_reftable_reflog_iterator_begin(struct ref_store *ref_store) +{ + struct git_reftable_reflog_ref_iterator *ri = xcalloc(1, sizeof(*ri)); + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + + if (refs->worktree_stack == NULL) { + struct reftable_stack *stack = refs->main_stack; + struct reftable_merged_table *mt = + reftable_stack_merged_table(stack); + int err = reftable_merged_table_seek_log(mt, &ri->iter, ""); + if (err < 0) { + free(ri); + /* XXX is this allowed? */ + return NULL; + } + } else { + struct reftable_merged_table *mt1 = + reftable_stack_merged_table(refs->main_stack); + struct reftable_merged_table *mt2 = + reftable_stack_merged_table(refs->worktree_stack); + struct reftable_table *tabs = + xcalloc(2, sizeof(struct reftable_table)); + int err = 0; + reftable_table_from_merged_table(&tabs[0], mt1); + reftable_table_from_merged_table(&tabs[1], mt2); + err = reftable_new_merged_table(&ri->merged, tabs, 2, + the_hash_algo->format_id); + if (err < 0) { + free(tabs); + /* XXX see above */ + return NULL; + } + err = reftable_merged_table_seek_ref(ri->merged, &ri->iter, ""); + if (err < 0) { + return NULL; + } + } + base_ref_iterator_init(&ri->base, + &git_reftable_reflog_ref_iterator_vtable, 1); + ri->base.oid = &ri->oid; + + return (struct ref_iterator *)ri; +} + +static int git_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_stack *stack = stack_for(refs, refname); + 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(stack); + err = reftable_merged_table_seek_log(mt, &it, refname); + while (err == 0) { + struct object_id old_oid; + struct object_id new_oid; + const char *full_committer = ""; + + err = reftable_iterator_next_log(&it, &log); + if (err > 0) { + err = 0; + break; + } + if (err < 0) { + break; + } + + if (strcmp(log.refname, refname)) { + break; + } + + hashcpy(old_oid.hash, log.update.old_hash); + hashcpy(new_oid.hash, log.update.new_hash); + + full_committer = fmt_ident(log.update.name, log.update.email, + WANT_COMMITTER_IDENT, + /*date*/ NULL, IDENT_NO_DATE); + err = fn(&old_oid, &new_oid, full_committer, log.update.time, + log.update.tz_offset, log.update.message, cb_data); + if (err) + break; + } + + reftable_log_record_release(&log); + reftable_iterator_destroy(&it); + return err; +} + +static int git_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_stack *stack = stack_for(refs, refname); + struct reftable_merged_table *mt = NULL; + struct reftable_log_record *logs = NULL; + int cap = 0; + int len = 0; + int err = 0; + int i = 0; + + if (refs->err < 0) { + return refs->err; + } + mt = reftable_stack_merged_table(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) { + err = 0; + break; + } + if (err < 0) { + break; + } + + if (strcmp(log.refname, refname)) { + break; + } + + if (len == cap) { + cap = 2 * cap + 1; + logs = realloc(logs, cap * sizeof(*logs)); + } + + logs[len++] = log; + } + + for (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->update.old_hash); + hashcpy(new_oid.hash, log->update.new_hash); + + full_committer = fmt_ident(log->update.name, log->update.email, + WANT_COMMITTER_IDENT, NULL, + IDENT_NO_DATE); + err = fn(&old_oid, &new_oid, full_committer, log->update.time, + log->update.tz_offset, log->update.message, cb_data); + if (err) { + break; + } + } + + for (i = 0; i < len; i++) { + reftable_log_record_release(&logs[i]); + } + free(logs); + + reftable_iterator_destroy(&it); + return err; +} + +static int git_reftable_reflog_exists(struct ref_store *ref_store, + const char *refname) +{ + struct reftable_iterator it = { NULL }; + struct git_reftable_ref_store *refs = + (struct git_reftable_ref_store *)ref_store; + struct reftable_stack *stack = stack_for(refs, refname); + struct reftable_merged_table *mt = reftable_stack_merged_table(stack); + struct reftable_log_record log = { NULL }; + int err = refs->err; + + if (err < 0) { + goto done; + } + err = reftable_merged_table_seek_log(mt, &it, refname); + if (err) { + goto done; + } + err = reftable_iterator_next_log(&it, &log); + if (err) { + goto done; + } + + if (strcmp(log.refname, refname)) { + err = 1; + } + +done: + reftable_iterator_destroy(&it); + reftable_log_record_release(&log); + return !err; +} + +static int git_reftable_create_reflog(struct ref_store *ref_store, + const char *refname, int force_create, + struct strbuf *err) +{ + return 0; +} + +static int git_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_stack *stack; + 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_release(&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 = { + .refname = 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->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 +git_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 + git_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_stack *stack = stack_for(refs, refname); + struct reftable_merged_table *mt = NULL; + struct reflog_expiry_arg arg = { + .stack = stack, + .refs = refs, + }; + struct reftable_log_record log = { NULL }; + struct reftable_iterator it = { NULL }; + int err = 0; + if (refs->err < 0) { + return refs->err; + } + err = reftable_stack_reload(stack); + if (err) { + goto done; + } + + mt = reftable_stack_merged_table(stack); + err = reftable_merged_table_seek_log(mt, &it, refname); + if (err < 0) { + goto done; + } + + while (1) { + struct object_id ooid; + struct object_id noid; + + int err = reftable_iterator_next_log(&it, &log); + if (err < 0) { + goto done; + } + + if (err > 0 || strcmp(log.refname, refname)) { + break; + } + hashcpy(ooid.hash, log.update.old_hash); + hashcpy(noid.hash, log.update.new_hash); + + if (should_prune_fn(&ooid, &noid, log.update.email, + (timestamp_t)log.update.time, + log.update.tz_offset, log.update.message, + policy_cb_data)) { + add_log_tombstone(&arg, refname, log.update_index); + } + } + err = reftable_stack_add(stack, &write_reflog_expiry_table, &arg); + +done: + assert(err != REFTABLE_API_ERROR); + reftable_log_record_release(&log); + reftable_iterator_destroy(&it); + clear_log_tombstones(&arg); + return err; +} + +static int reftable_error_to_errno(int err) +{ + switch (err) { + case REFTABLE_IO_ERROR: + return EIO; + case REFTABLE_FORMAT_ERROR: + return EFAULT; + case REFTABLE_NOT_EXIST_ERROR: + return ENOENT; + case REFTABLE_LOCK_ERROR: + return EBUSY; + case REFTABLE_API_ERROR: + return EINVAL; + case REFTABLE_ZLIB_ERROR: + return EDOM; + default: + return ERANGE; + } +} + +static int git_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_stack *stack = stack_for(refs, refname); + + struct reftable_ref_record ref = { NULL }; + int err = 0; + if (refs->err < 0) { + return refs->err; + } + + /* This is usually not needed, but Git doesn't signal to ref backend if + a subprocess updated the ref DB. So we always check. + */ + err = reftable_stack_reload(stack); + if (err) { + goto done; + } + + err = reftable_stack_read_ref(stack, refname, &ref); + if (err > 0) { + errno = ENOENT; + err = -1; + goto done; + } + if (err < 0) { + errno = reftable_error_to_errno(err); + err = -1; + goto done; + } + + if (ref.value_type == REFTABLE_REF_SYMREF) { + strbuf_reset(referent); + strbuf_addstr(referent, ref.value.symref); + *type |= REF_ISSYMREF; + } else if (reftable_ref_record_val1(&ref) != NULL) { + hashcpy(oid->hash, reftable_ref_record_val1(&ref)); + } else { + *type |= REF_ISBROKEN; + errno = EINVAL; + err = -1; + } +done: + assert(err != REFTABLE_API_ERROR); + reftable_ref_record_release(&ref); + return err; +} + +struct ref_storage_be refs_be_reftable = { + &refs_be_files, + "reftable", + git_reftable_ref_store_create, + git_reftable_init_db, + git_reftable_transaction_prepare, + git_reftable_transaction_finish, + git_reftable_transaction_abort, + git_reftable_transaction_initial_commit, + + git_reftable_pack_refs, + git_reftable_create_symref, + git_reftable_delete_refs, + git_reftable_rename_ref, + git_reftable_copy_ref, + + git_reftable_ref_iterator_begin, + git_reftable_read_raw_ref, + + git_reftable_reflog_iterator_begin, + git_reftable_for_each_reflog_ent_oldest_first, + git_reftable_for_each_reflog_ent_newest_first, + git_reftable_reflog_exists, + git_reftable_create_reflog, + git_reftable_delete_reflog, + git_reftable_reflog_expire, +}; diff --git a/repository.c b/repository.c index c98298acd017..4d8f572fc9cd 100644 --- a/repository.c +++ b/repository.c @@ -174,6 +174,8 @@ 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 b385ca3c94b6..8019a7d0a1fc 100644 --- a/repository.h +++ b/repository.h @@ -78,6 +78,9 @@ struct repository { */ struct ref_store *refs_private; + /* 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 c04cd25a30df..c6b57efd0318 100644 --- a/setup.c +++ b/setup.c @@ -500,6 +500,9 @@ static enum extension_result handle_extension(const char *var, return error("invalid value for 'extensions.objectformat'"); data->hash_algo = format; return EXTENSION_OK; + } else if (!strcmp(ext, "refstorage")) { + data->ref_storage = xstrdup(value); + return EXTENSION_OK; } return EXTENSION_UNKNOWN; } @@ -651,6 +654,7 @@ void clear_repository_format(struct repository_format *format) string_list_clear(&format->v1_only_extensions, 0); free(format->work_tree); free(format->partial_clone); + free(format->ref_storage); init_repository_format(format); } @@ -1308,8 +1312,11 @@ 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 000000000000..ba0738e51561 --- /dev/null +++ b/t/t0031-reftable.sh @@ -0,0 +1,203 @@ +#!/bin/sh +# +# Copyright (c) 2020 Google LLC +# + +test_description='reftable basics' + +. ./test-lib.sh + +INVALID_SHA1=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + +git_init () { + git init -b primary "$@" +} + +initialize () { + rm -rf .git && + git_init --ref-storage=reftable && + mv .git/hooks .git/hooks-disabled +} + +test_expect_success 'SHA256 support, env' ' + rm -rf .git && + GIT_DEFAULT_HASH=sha256 && export GIT_DEFAULT_HASH && + git_init --ref-storage=reftable && + mv .git/hooks .git/hooks-disabled && + test_commit file +' + +test_expect_success 'SHA256 support, option' ' + rm -rf .git && + git_init --ref-storage=reftable --object-format=sha256 && + mv .git/hooks .git/hooks-disabled && + test_commit file +' + +test_expect_success 'delete ref' ' + initialize && + test_commit file && + SHA=$(git show-ref -s --verify HEAD) && + test_write_lines "$SHA refs/heads/primary" "$SHA refs/tags/file" >expect && + git show-ref >actual && + ! git update-ref -d refs/tags/file $INVALID_SHA1 && + test_cmp expect actual && + git update-ref -d refs/tags/file $SHA && + test_write_lines "$SHA refs/heads/primary" >expect && + git show-ref >actual && + test_cmp expect actual +' + + +test_expect_success 'clone calls transaction_initial_commit' ' + test_commit message1 file1 && + git clone . cloned && + (test -f cloned/file1 || echo "Fixme.") +' + +test_expect_success 'basic operation of reftable storage: commit, show-ref' ' + initialize && + test_commit file && + test_write_lines refs/heads/primary refs/tags/file >expect && + git show-ref && + git show-ref | cut -f2 -d" " >actual && + test_cmp actual expect +' + +test_expect_success 'reflog, repack' ' + initialize && + for count in $(test_seq 1 10) + do + test_commit "number $count" file.t $count number-$count || + return 1 + done && + git pack-refs && + ls -1 .git/reftable >table-files && + test_line_count = 2 table-files && + git reflog refs/heads/primary >output && + test_line_count = 10 output && + grep "commit (initial): number 1" output && + grep "commit: number 10" output && + git gc && + git reflog refs/heads/primary >output && + test_line_count = 0 output +' + +test_expect_success 'branch switch in reflog output' ' + initialize && + test_commit file1 && + git checkout -b branch1 && + test_commit file2 && + git checkout -b branch2 && + git switch - && + git rev-parse --symbolic-full-name HEAD >actual && + echo refs/heads/branch1 >expect && + test_cmp actual expect +' + + +# This matches show-ref's output +print_ref() { + echo "$(git rev-parse "$1") $1" +} + +test_expect_success 'peeled tags are stored' ' + initialize && + test_commit file && + git tag -m "annotated tag" test_tag HEAD && + { + print_ref "refs/heads/primary" && + print_ref "refs/tags/file" && + print_ref "refs/tags/test_tag" && + print_ref "refs/tags/test_tag^{}" + } >expect && + git show-ref -d >actual && + test_cmp expect actual +' + +test_expect_success 'show-ref works on fresh repo' ' + initialize && + rm -rf .git && + git_init --ref-storage=reftable && + >expect && + ! git show-ref >actual && + test_cmp expect actual +' + +test_expect_success 'checkout unborn branch' ' + initialize && + git checkout -b primary +' + + +test_expect_success 'dir/file conflict' ' + initialize && + test_commit file && + ! git branch primary/forbidden +' + + +test_expect_success 'do not clobber existing repo' ' + rm -rf .git && + git_init --ref-storage=files && + cat .git/HEAD >expect && + test_commit file && + (git_init --ref-storage=reftable || true) && + cat .git/HEAD >actual && + test_cmp expect actual +' + +# cherry-pick uses a pseudo ref. +test_expect_success 'pseudo refs' ' + initialize && + test_commit message1 file1 && + test_commit message2 file2 && + git branch source && + git checkout HEAD^ && + test_commit message3 file3 && + git cherry-pick source && + test -f file2 +' + +# cherry-pick uses a pseudo ref. +test_expect_success 'rebase' ' + initialize && + test_commit message1 file1 && + test_commit message2 file2 && + git branch source && + git checkout HEAD^ && + test_commit message3 file3 && + git rebase source && + test -f file2 +' + +test_expect_success 'worktrees' ' + git_init --ref-storage=reftable start && + (cd start && test_commit file1 && git checkout -b branch1 && + git checkout -b branch2 && + git worktree add ../wt + ) && + cd wt && + git checkout branch1 && + git branch +' + +test_expect_success 'worktrees 2' ' + initialize && + test_commit file1 && + mkdir existing_empty && + git worktree add --detach existing_empty primary +' + +test_expect_success 'FETCH_HEAD' ' + initialize && + test_commit one && + (git_init sub && cd sub && test_commit two) && + git --git-dir sub/.git rev-parse HEAD >expect && + git fetch sub && + git checkout FETCH_HEAD && + git rev-parse HEAD >actual && + test_cmp expect actual +' + +test_done diff --git a/t/t1409-avoid-packing-refs.sh b/t/t1409-avoid-packing-refs.sh index be12fb63506e..c6f783255633 100755 --- a/t/t1409-avoid-packing-refs.sh +++ b/t/t1409-avoid-packing-refs.sh @@ -4,6 +4,12 @@ test_description='avoid rewriting packed-refs unnecessarily' . ./test-lib.sh +if test_have_prereq REFTABLE +then + skip_all='skipping pack-refs tests; incompatible with reftable' + test_done +fi + # Add an identifying mark to the packed-refs file header line. This # shouldn't upset readers, and it should be omitted if the file is # ever rewritten. diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh index 5071ac63a5b5..16440d58d6bb 100755 --- a/t/t1450-fsck.sh +++ b/t/t1450-fsck.sh @@ -8,6 +8,12 @@ test_description='git fsck random collection of tests . ./test-lib.sh +if test_have_prereq REFTABLE +then + skip_all='skipping tests; incompatible with reftable' + test_done +fi + test_expect_success setup ' git config gc.auto 0 && git config i18n.commitencoding ISO-8859-1 && diff --git a/t/t3210-pack-refs.sh b/t/t3210-pack-refs.sh index 3b7cdc56ec84..667a23affe36 100755 --- a/t/t3210-pack-refs.sh +++ b/t/t3210-pack-refs.sh @@ -14,6 +14,12 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME . ./test-lib.sh +if test_have_prereq REFTABLE +then + skip_all='skipping pack-refs tests; incompatible with reftable' + test_done +fi + test_expect_success 'enable reflogs' ' git config core.logallrefupdates true ' diff --git a/t/test-lib.sh b/t/test-lib.sh index d3f6af6a6545..943aa9713961 100644 --- a/t/test-lib.sh +++ b/t/test-lib.sh @@ -1481,6 +1481,11 @@ parisc* | hppa*) ;; esac +if test -n "$GIT_TEST_REFTABLE" +then + test_set_prereq REFTABLE +fi + ( COLUMNS=1 && test $COLUMNS = 1 ) && test_set_prereq COLUMNS_CAN_BE_1 test -z "$NO_PERL" && test_set_prereq PERL test -z "$NO_PTHREADS" && test_set_prereq PTHREADS
-- gitgitgadget