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author | Junio C Hamano <gitster@pobox.com> | 2024-03-28 14:13:50 -0700 |
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committer | Junio C Hamano <gitster@pobox.com> | 2024-03-28 14:13:50 -0700 |
commit | 1002f28a527d33893f7dab068dbac7011f84af65 (patch) | |
tree | 9b9ada23d952e936d496597d03064c10d8d9f73d /loose.c | |
parent | c75fd8d8150afdf836b63a8e0534d9b9e3e111ba (diff) | |
parent | 7673ecd2dcdcf0aae01cccdb5c25f9b96160a8c0 (diff) | |
download | git-1002f28a527d33893f7dab068dbac7011f84af65.tar.gz |
Merge branch 'eb/hash-transition'
Work to support a repository that work with both SHA-1 and SHA-256
hash algorithms has started.
* eb/hash-transition: (30 commits)
t1016-compatObjectFormat: add tests to verify the conversion between objects
t1006: test oid compatibility with cat-file
t1006: rename sha1 to oid
test-lib: compute the compatibility hash so tests may use it
builtin/ls-tree: let the oid determine the output algorithm
object-file: handle compat objects in check_object_signature
tree-walk: init_tree_desc take an oid to get the hash algorithm
builtin/cat-file: let the oid determine the output algorithm
rev-parse: add an --output-object-format parameter
repository: implement extensions.compatObjectFormat
object-file: update object_info_extended to reencode objects
object-file-convert: convert commits that embed signed tags
object-file-convert: convert commit objects when writing
object-file-convert: don't leak when converting tag objects
object-file-convert: convert tag objects when writing
object-file-convert: add a function to convert trees between algorithms
object: factor out parse_mode out of fast-import and tree-walk into in object.h
cache: add a function to read an OID of a specific algorithm
tag: sign both hashes
commit: export add_header_signature to support handling signatures on tags
...
Diffstat (limited to 'loose.c')
-rw-r--r-- | loose.c | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/loose.c b/loose.c new file mode 100644 index 0000000000..f6faa6216a --- /dev/null +++ b/loose.c @@ -0,0 +1,259 @@ +#include "git-compat-util.h" +#include "hash.h" +#include "path.h" +#include "object-store.h" +#include "hex.h" +#include "wrapper.h" +#include "gettext.h" +#include "loose.h" +#include "lockfile.h" +#include "oidtree.h" + +static const char *loose_object_header = "# loose-object-idx\n"; + +static inline int should_use_loose_object_map(struct repository *repo) +{ + return repo->compat_hash_algo && repo->gitdir; +} + +void loose_object_map_init(struct loose_object_map **map) +{ + struct loose_object_map *m; + m = xmalloc(sizeof(**map)); + m->to_compat = kh_init_oid_map(); + m->to_storage = kh_init_oid_map(); + *map = m; +} + +static int insert_oid_pair(kh_oid_map_t *map, const struct object_id *key, const struct object_id *value) +{ + khiter_t pos; + int ret; + struct object_id *stored; + + pos = kh_put_oid_map(map, *key, &ret); + + /* This item already exists in the map. */ + if (ret == 0) + return 0; + + stored = xmalloc(sizeof(*stored)); + oidcpy(stored, value); + kh_value(map, pos) = stored; + return 1; +} + +static int insert_loose_map(struct object_directory *odb, + const struct object_id *oid, + const struct object_id *compat_oid) +{ + struct loose_object_map *map = odb->loose_map; + int inserted = 0; + + inserted |= insert_oid_pair(map->to_compat, oid, compat_oid); + inserted |= insert_oid_pair(map->to_storage, compat_oid, oid); + if (inserted) + oidtree_insert(odb->loose_objects_cache, compat_oid); + + return inserted; +} + +static int load_one_loose_object_map(struct repository *repo, struct object_directory *dir) +{ + struct strbuf buf = STRBUF_INIT, path = STRBUF_INIT; + FILE *fp; + + if (!dir->loose_map) + loose_object_map_init(&dir->loose_map); + if (!dir->loose_objects_cache) { + ALLOC_ARRAY(dir->loose_objects_cache, 1); + oidtree_init(dir->loose_objects_cache); + } + + insert_loose_map(dir, repo->hash_algo->empty_tree, repo->compat_hash_algo->empty_tree); + insert_loose_map(dir, repo->hash_algo->empty_blob, repo->compat_hash_algo->empty_blob); + insert_loose_map(dir, repo->hash_algo->null_oid, repo->compat_hash_algo->null_oid); + + strbuf_git_common_path(&path, repo, "objects/loose-object-idx"); + fp = fopen(path.buf, "rb"); + if (!fp) { + strbuf_release(&path); + return 0; + } + + errno = 0; + if (strbuf_getwholeline(&buf, fp, '\n') || strcmp(buf.buf, loose_object_header)) + goto err; + while (!strbuf_getline_lf(&buf, fp)) { + const char *p; + struct object_id oid, compat_oid; + if (parse_oid_hex_algop(buf.buf, &oid, &p, repo->hash_algo) || + *p++ != ' ' || + parse_oid_hex_algop(p, &compat_oid, &p, repo->compat_hash_algo) || + p != buf.buf + buf.len) + goto err; + insert_loose_map(dir, &oid, &compat_oid); + } + + strbuf_release(&buf); + strbuf_release(&path); + return errno ? -1 : 0; +err: + strbuf_release(&buf); + strbuf_release(&path); + return -1; +} + +int repo_read_loose_object_map(struct repository *repo) +{ + struct object_directory *dir; + + if (!should_use_loose_object_map(repo)) + return 0; + + prepare_alt_odb(repo); + + for (dir = repo->objects->odb; dir; dir = dir->next) { + if (load_one_loose_object_map(repo, dir) < 0) { + return -1; + } + } + return 0; +} + +int repo_write_loose_object_map(struct repository *repo) +{ + kh_oid_map_t *map = repo->objects->odb->loose_map->to_compat; + struct lock_file lock; + int fd; + khiter_t iter; + struct strbuf buf = STRBUF_INIT, path = STRBUF_INIT; + + if (!should_use_loose_object_map(repo)) + return 0; + + strbuf_git_common_path(&path, repo, "objects/loose-object-idx"); + fd = hold_lock_file_for_update_timeout(&lock, path.buf, LOCK_DIE_ON_ERROR, -1); + iter = kh_begin(map); + if (write_in_full(fd, loose_object_header, strlen(loose_object_header)) < 0) + goto errout; + + for (; iter != kh_end(map); iter++) { + if (kh_exist(map, iter)) { + if (oideq(&kh_key(map, iter), the_hash_algo->empty_tree) || + oideq(&kh_key(map, iter), the_hash_algo->empty_blob)) + continue; + strbuf_addf(&buf, "%s %s\n", oid_to_hex(&kh_key(map, iter)), oid_to_hex(kh_value(map, iter))); + if (write_in_full(fd, buf.buf, buf.len) < 0) + goto errout; + strbuf_reset(&buf); + } + } + strbuf_release(&buf); + if (commit_lock_file(&lock) < 0) { + error_errno(_("could not write loose object index %s"), path.buf); + strbuf_release(&path); + return -1; + } + strbuf_release(&path); + return 0; +errout: + rollback_lock_file(&lock); + strbuf_release(&buf); + error_errno(_("failed to write loose object index %s\n"), path.buf); + strbuf_release(&path); + return -1; +} + +static int write_one_object(struct repository *repo, const struct object_id *oid, + const struct object_id *compat_oid) +{ + struct lock_file lock; + int fd; + struct stat st; + struct strbuf buf = STRBUF_INIT, path = STRBUF_INIT; + + strbuf_git_common_path(&path, repo, "objects/loose-object-idx"); + hold_lock_file_for_update_timeout(&lock, path.buf, LOCK_DIE_ON_ERROR, -1); + + fd = open(path.buf, O_WRONLY | O_CREAT | O_APPEND, 0666); + if (fd < 0) + goto errout; + if (fstat(fd, &st) < 0) + goto errout; + if (!st.st_size && write_in_full(fd, loose_object_header, strlen(loose_object_header)) < 0) + goto errout; + + strbuf_addf(&buf, "%s %s\n", oid_to_hex(oid), oid_to_hex(compat_oid)); + if (write_in_full(fd, buf.buf, buf.len) < 0) + goto errout; + if (close(fd)) + goto errout; + adjust_shared_perm(path.buf); + rollback_lock_file(&lock); + strbuf_release(&buf); + strbuf_release(&path); + return 0; +errout: + error_errno(_("failed to write loose object index %s\n"), path.buf); + close(fd); + rollback_lock_file(&lock); + strbuf_release(&buf); + strbuf_release(&path); + return -1; +} + +int repo_add_loose_object_map(struct repository *repo, const struct object_id *oid, + const struct object_id *compat_oid) +{ + int inserted = 0; + + if (!should_use_loose_object_map(repo)) + return 0; + + inserted = insert_loose_map(repo->objects->odb, oid, compat_oid); + if (inserted) + return write_one_object(repo, oid, compat_oid); + return 0; +} + +int repo_loose_object_map_oid(struct repository *repo, + const struct object_id *src, + const struct git_hash_algo *to, + struct object_id *dest) +{ + struct object_directory *dir; + kh_oid_map_t *map; + khiter_t pos; + + for (dir = repo->objects->odb; dir; dir = dir->next) { + struct loose_object_map *loose_map = dir->loose_map; + if (!loose_map) + continue; + map = (to == repo->compat_hash_algo) ? + loose_map->to_compat : + loose_map->to_storage; + pos = kh_get_oid_map(map, *src); + if (pos < kh_end(map)) { + oidcpy(dest, kh_value(map, pos)); + return 0; + } + } + return -1; +} + +void loose_object_map_clear(struct loose_object_map **map) +{ + struct loose_object_map *m = *map; + struct object_id *oid; + + if (!m) + return; + + kh_foreach_value(m->to_compat, oid, free(oid)); + kh_foreach_value(m->to_storage, oid, free(oid)); + kh_destroy_oid_map(m->to_compat); + kh_destroy_oid_map(m->to_storage); + free(m); + *map = NULL; +} |