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-rw-r--r--object-file.c2625
1 files changed, 2625 insertions, 0 deletions
diff --git a/object-file.c b/object-file.c
new file mode 100644
index 0000000000..a8be899481
--- /dev/null
+++ b/object-file.c
@@ -0,0 +1,2625 @@
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ *
+ * This handles basic git object files - packing, unpacking,
+ * creation etc.
+ */
+#include "cache.h"
+#include "config.h"
+#include "string-list.h"
+#include "lockfile.h"
+#include "delta.h"
+#include "pack.h"
+#include "blob.h"
+#include "commit.h"
+#include "run-command.h"
+#include "tag.h"
+#include "tree.h"
+#include "tree-walk.h"
+#include "refs.h"
+#include "pack-revindex.h"
+#include "hash-lookup.h"
+#include "bulk-checkin.h"
+#include "repository.h"
+#include "replace-object.h"
+#include "streaming.h"
+#include "dir.h"
+#include "list.h"
+#include "mergesort.h"
+#include "quote.h"
+#include "packfile.h"
+#include "object-store.h"
+#include "promisor-remote.h"
+
+/* The maximum size for an object header. */
+#define MAX_HEADER_LEN 32
+
+
+#define EMPTY_TREE_SHA1_BIN_LITERAL \
+ "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60" \
+ "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04"
+#define EMPTY_TREE_SHA256_BIN_LITERAL \
+ "\x6e\xf1\x9b\x41\x22\x5c\x53\x69\xf1\xc1" \
+ "\x04\xd4\x5d\x8d\x85\xef\xa9\xb0\x57\xb5" \
+ "\x3b\x14\xb4\xb9\xb9\x39\xdd\x74\xde\xcc" \
+ "\x53\x21"
+
+#define EMPTY_BLOB_SHA1_BIN_LITERAL \
+ "\xe6\x9d\xe2\x9b\xb2\xd1\xd6\x43\x4b\x8b" \
+ "\x29\xae\x77\x5a\xd8\xc2\xe4\x8c\x53\x91"
+#define EMPTY_BLOB_SHA256_BIN_LITERAL \
+ "\x47\x3a\x0f\x4c\x3b\xe8\xa9\x36\x81\xa2" \
+ "\x67\xe3\xb1\xe9\xa7\xdc\xda\x11\x85\x43" \
+ "\x6f\xe1\x41\xf7\x74\x91\x20\xa3\x03\x72" \
+ "\x18\x13"
+
+static const struct object_id empty_tree_oid = {
+ .hash = EMPTY_TREE_SHA1_BIN_LITERAL,
+ .algo = GIT_HASH_SHA1,
+};
+static const struct object_id empty_blob_oid = {
+ .hash = EMPTY_BLOB_SHA1_BIN_LITERAL,
+ .algo = GIT_HASH_SHA1,
+};
+static const struct object_id null_oid_sha1 = {
+ .hash = {0},
+ .algo = GIT_HASH_SHA1,
+};
+static const struct object_id empty_tree_oid_sha256 = {
+ .hash = EMPTY_TREE_SHA256_BIN_LITERAL,
+ .algo = GIT_HASH_SHA256,
+};
+static const struct object_id empty_blob_oid_sha256 = {
+ .hash = EMPTY_BLOB_SHA256_BIN_LITERAL,
+ .algo = GIT_HASH_SHA256,
+};
+static const struct object_id null_oid_sha256 = {
+ .hash = {0},
+ .algo = GIT_HASH_SHA256,
+};
+
+static void git_hash_sha1_init(git_hash_ctx *ctx)
+{
+ git_SHA1_Init(&ctx->sha1);
+}
+
+static void git_hash_sha1_clone(git_hash_ctx *dst, const git_hash_ctx *src)
+{
+ git_SHA1_Clone(&dst->sha1, &src->sha1);
+}
+
+static void git_hash_sha1_update(git_hash_ctx *ctx, const void *data, size_t len)
+{
+ git_SHA1_Update(&ctx->sha1, data, len);
+}
+
+static void git_hash_sha1_final(unsigned char *hash, git_hash_ctx *ctx)
+{
+ git_SHA1_Final(hash, &ctx->sha1);
+}
+
+static void git_hash_sha1_final_oid(struct object_id *oid, git_hash_ctx *ctx)
+{
+ git_SHA1_Final(oid->hash, &ctx->sha1);
+ memset(oid->hash + GIT_SHA1_RAWSZ, 0, GIT_MAX_RAWSZ - GIT_SHA1_RAWSZ);
+ oid->algo = GIT_HASH_SHA1;
+}
+
+
+static void git_hash_sha256_init(git_hash_ctx *ctx)
+{
+ git_SHA256_Init(&ctx->sha256);
+}
+
+static void git_hash_sha256_clone(git_hash_ctx *dst, const git_hash_ctx *src)
+{
+ git_SHA256_Clone(&dst->sha256, &src->sha256);
+}
+
+static void git_hash_sha256_update(git_hash_ctx *ctx, const void *data, size_t len)
+{
+ git_SHA256_Update(&ctx->sha256, data, len);
+}
+
+static void git_hash_sha256_final(unsigned char *hash, git_hash_ctx *ctx)
+{
+ git_SHA256_Final(hash, &ctx->sha256);
+}
+
+static void git_hash_sha256_final_oid(struct object_id *oid, git_hash_ctx *ctx)
+{
+ git_SHA256_Final(oid->hash, &ctx->sha256);
+ /*
+ * This currently does nothing, so the compiler should optimize it out,
+ * but keep it in case we extend the hash size again.
+ */
+ memset(oid->hash + GIT_SHA256_RAWSZ, 0, GIT_MAX_RAWSZ - GIT_SHA256_RAWSZ);
+ oid->algo = GIT_HASH_SHA256;
+}
+
+static void git_hash_unknown_init(git_hash_ctx *ctx)
+{
+ BUG("trying to init unknown hash");
+}
+
+static void git_hash_unknown_clone(git_hash_ctx *dst, const git_hash_ctx *src)
+{
+ BUG("trying to clone unknown hash");
+}
+
+static void git_hash_unknown_update(git_hash_ctx *ctx, const void *data, size_t len)
+{
+ BUG("trying to update unknown hash");
+}
+
+static void git_hash_unknown_final(unsigned char *hash, git_hash_ctx *ctx)
+{
+ BUG("trying to finalize unknown hash");
+}
+
+static void git_hash_unknown_final_oid(struct object_id *oid, git_hash_ctx *ctx)
+{
+ BUG("trying to finalize unknown hash");
+}
+
+
+const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = {
+ {
+ NULL,
+ 0x00000000,
+ 0,
+ 0,
+ 0,
+ git_hash_unknown_init,
+ git_hash_unknown_clone,
+ git_hash_unknown_update,
+ git_hash_unknown_final,
+ git_hash_unknown_final_oid,
+ NULL,
+ NULL,
+ NULL,
+ },
+ {
+ "sha1",
+ /* "sha1", big-endian */
+ 0x73686131,
+ GIT_SHA1_RAWSZ,
+ GIT_SHA1_HEXSZ,
+ GIT_SHA1_BLKSZ,
+ git_hash_sha1_init,
+ git_hash_sha1_clone,
+ git_hash_sha1_update,
+ git_hash_sha1_final,
+ git_hash_sha1_final_oid,
+ &empty_tree_oid,
+ &empty_blob_oid,
+ &null_oid_sha1,
+ },
+ {
+ "sha256",
+ /* "s256", big-endian */
+ 0x73323536,
+ GIT_SHA256_RAWSZ,
+ GIT_SHA256_HEXSZ,
+ GIT_SHA256_BLKSZ,
+ git_hash_sha256_init,
+ git_hash_sha256_clone,
+ git_hash_sha256_update,
+ git_hash_sha256_final,
+ git_hash_sha256_final_oid,
+ &empty_tree_oid_sha256,
+ &empty_blob_oid_sha256,
+ &null_oid_sha256,
+ }
+};
+
+const struct object_id *null_oid(void)
+{
+ return the_hash_algo->null_oid;
+}
+
+const char *empty_tree_oid_hex(void)
+{
+ static char buf[GIT_MAX_HEXSZ + 1];
+ return oid_to_hex_r(buf, the_hash_algo->empty_tree);
+}
+
+const char *empty_blob_oid_hex(void)
+{
+ static char buf[GIT_MAX_HEXSZ + 1];
+ return oid_to_hex_r(buf, the_hash_algo->empty_blob);
+}
+
+int hash_algo_by_name(const char *name)
+{
+ int i;
+ if (!name)
+ return GIT_HASH_UNKNOWN;
+ for (i = 1; i < GIT_HASH_NALGOS; i++)
+ if (!strcmp(name, hash_algos[i].name))
+ return i;
+ return GIT_HASH_UNKNOWN;
+}
+
+int hash_algo_by_id(uint32_t format_id)
+{
+ int i;
+ for (i = 1; i < GIT_HASH_NALGOS; i++)
+ if (format_id == hash_algos[i].format_id)
+ return i;
+ return GIT_HASH_UNKNOWN;
+}
+
+int hash_algo_by_length(int len)
+{
+ int i;
+ for (i = 1; i < GIT_HASH_NALGOS; i++)
+ if (len == hash_algos[i].rawsz)
+ return i;
+ return GIT_HASH_UNKNOWN;
+}
+
+/*
+ * This is meant to hold a *small* number of objects that you would
+ * want read_object_file() to be able to return, but yet you do not want
+ * to write them into the object store (e.g. a browse-only
+ * application).
+ */
+static struct cached_object {
+ struct object_id oid;
+ enum object_type type;
+ void *buf;
+ unsigned long size;
+} *cached_objects;
+static int cached_object_nr, cached_object_alloc;
+
+static struct cached_object empty_tree = {
+ { EMPTY_TREE_SHA1_BIN_LITERAL },
+ OBJ_TREE,
+ "",
+ 0
+};
+
+static struct cached_object *find_cached_object(const struct object_id *oid)
+{
+ int i;
+ struct cached_object *co = cached_objects;
+
+ for (i = 0; i < cached_object_nr; i++, co++) {
+ if (oideq(&co->oid, oid))
+ return co;
+ }
+ if (oideq(oid, the_hash_algo->empty_tree))
+ return &empty_tree;
+ return NULL;
+}
+
+
+static int get_conv_flags(unsigned flags)
+{
+ if (flags & HASH_RENORMALIZE)
+ return CONV_EOL_RENORMALIZE;
+ else if (flags & HASH_WRITE_OBJECT)
+ return global_conv_flags_eol | CONV_WRITE_OBJECT;
+ else
+ return 0;
+}
+
+
+int mkdir_in_gitdir(const char *path)
+{
+ if (mkdir(path, 0777)) {
+ int saved_errno = errno;
+ struct stat st;
+ struct strbuf sb = STRBUF_INIT;
+
+ if (errno != EEXIST)
+ return -1;
+ /*
+ * Are we looking at a path in a symlinked worktree
+ * whose original repository does not yet have it?
+ * e.g. .git/rr-cache pointing at its original
+ * repository in which the user hasn't performed any
+ * conflict resolution yet?
+ */
+ if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
+ strbuf_readlink(&sb, path, st.st_size) ||
+ !is_absolute_path(sb.buf) ||
+ mkdir(sb.buf, 0777)) {
+ strbuf_release(&sb);
+ errno = saved_errno;
+ return -1;
+ }
+ strbuf_release(&sb);
+ }
+ return adjust_shared_perm(path);
+}
+
+static enum scld_error safe_create_leading_directories_1(char *path, int share)
+{
+ char *next_component = path + offset_1st_component(path);
+ enum scld_error ret = SCLD_OK;
+
+ while (ret == SCLD_OK && next_component) {
+ struct stat st;
+ char *slash = next_component, slash_character;
+
+ while (*slash && !is_dir_sep(*slash))
+ slash++;
+
+ if (!*slash)
+ break;
+
+ next_component = slash + 1;
+ while (is_dir_sep(*next_component))
+ next_component++;
+ if (!*next_component)
+ break;
+
+ slash_character = *slash;
+ *slash = '\0';
+ if (!stat(path, &st)) {
+ /* path exists */
+ if (!S_ISDIR(st.st_mode)) {
+ errno = ENOTDIR;
+ ret = SCLD_EXISTS;
+ }
+ } else if (mkdir(path, 0777)) {
+ if (errno == EEXIST &&
+ !stat(path, &st) && S_ISDIR(st.st_mode))
+ ; /* somebody created it since we checked */
+ else if (errno == ENOENT)
+ /*
+ * Either mkdir() failed because
+ * somebody just pruned the containing
+ * directory, or stat() failed because
+ * the file that was in our way was
+ * just removed. Either way, inform
+ * the caller that it might be worth
+ * trying again:
+ */
+ ret = SCLD_VANISHED;
+ else
+ ret = SCLD_FAILED;
+ } else if (share && adjust_shared_perm(path)) {
+ ret = SCLD_PERMS;
+ }
+ *slash = slash_character;
+ }
+ return ret;
+}
+
+enum scld_error safe_create_leading_directories(char *path)
+{
+ return safe_create_leading_directories_1(path, 1);
+}
+
+enum scld_error safe_create_leading_directories_no_share(char *path)
+{
+ return safe_create_leading_directories_1(path, 0);
+}
+
+enum scld_error safe_create_leading_directories_const(const char *path)
+{
+ int save_errno;
+ /* path points to cache entries, so xstrdup before messing with it */
+ char *buf = xstrdup(path);
+ enum scld_error result = safe_create_leading_directories(buf);
+
+ save_errno = errno;
+ free(buf);
+ errno = save_errno;
+ return result;
+}
+
+int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
+{
+ /*
+ * The number of times we will try to remove empty directories
+ * in the way of path. This is only 1 because if another
+ * process is racily creating directories that conflict with
+ * us, we don't want to fight against them.
+ */
+ int remove_directories_remaining = 1;
+
+ /*
+ * The number of times that we will try to create the
+ * directories containing path. We are willing to attempt this
+ * more than once, because another process could be trying to
+ * clean up empty directories at the same time as we are
+ * trying to create them.
+ */
+ int create_directories_remaining = 3;
+
+ /* A scratch copy of path, filled lazily if we need it: */
+ struct strbuf path_copy = STRBUF_INIT;
+
+ int ret, save_errno;
+
+ /* Sanity check: */
+ assert(*path);
+
+retry_fn:
+ ret = fn(path, cb);
+ save_errno = errno;
+ if (!ret)
+ goto out;
+
+ if (errno == EISDIR && remove_directories_remaining-- > 0) {
+ /*
+ * A directory is in the way. Maybe it is empty; try
+ * to remove it:
+ */
+ if (!path_copy.len)
+ strbuf_addstr(&path_copy, path);
+
+ if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
+ goto retry_fn;
+ } else if (errno == ENOENT && create_directories_remaining-- > 0) {
+ /*
+ * Maybe the containing directory didn't exist, or
+ * maybe it was just deleted by a process that is
+ * racing with us to clean up empty directories. Try
+ * to create it:
+ */
+ enum scld_error scld_result;
+
+ if (!path_copy.len)
+ strbuf_addstr(&path_copy, path);
+
+ do {
+ scld_result = safe_create_leading_directories(path_copy.buf);
+ if (scld_result == SCLD_OK)
+ goto retry_fn;
+ } while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
+ }
+
+out:
+ strbuf_release(&path_copy);
+ errno = save_errno;
+ return ret;
+}
+
+static void fill_loose_path(struct strbuf *buf, const struct object_id *oid)
+{
+ int i;
+ for (i = 0; i < the_hash_algo->rawsz; i++) {
+ static char hex[] = "0123456789abcdef";
+ unsigned int val = oid->hash[i];
+ strbuf_addch(buf, hex[val >> 4]);
+ strbuf_addch(buf, hex[val & 0xf]);
+ if (!i)
+ strbuf_addch(buf, '/');
+ }
+}
+
+static const char *odb_loose_path(struct object_directory *odb,
+ struct strbuf *buf,
+ const struct object_id *oid)
+{
+ strbuf_reset(buf);
+ strbuf_addstr(buf, odb->path);
+ strbuf_addch(buf, '/');
+ fill_loose_path(buf, oid);
+ return buf->buf;
+}
+
+const char *loose_object_path(struct repository *r, struct strbuf *buf,
+ const struct object_id *oid)
+{
+ return odb_loose_path(r->objects->odb, buf, oid);
+}
+
+/*
+ * Return non-zero iff the path is usable as an alternate object database.
+ */
+static int alt_odb_usable(struct raw_object_store *o,
+ struct strbuf *path,
+ const char *normalized_objdir, khiter_t *pos)
+{
+ int r;
+
+ /* Detect cases where alternate disappeared */
+ if (!is_directory(path->buf)) {
+ error(_("object directory %s does not exist; "
+ "check .git/objects/info/alternates"),
+ path->buf);
+ return 0;
+ }
+
+ /*
+ * Prevent the common mistake of listing the same
+ * thing twice, or object directory itself.
+ */
+ if (!o->odb_by_path) {
+ khiter_t p;
+
+ o->odb_by_path = kh_init_odb_path_map();
+ assert(!o->odb->next);
+ p = kh_put_odb_path_map(o->odb_by_path, o->odb->path, &r);
+ assert(r == 1); /* never used */
+ kh_value(o->odb_by_path, p) = o->odb;
+ }
+ if (fspatheq(path->buf, normalized_objdir))
+ return 0;
+ *pos = kh_put_odb_path_map(o->odb_by_path, path->buf, &r);
+ /* r: 0 = exists, 1 = never used, 2 = deleted */
+ return r == 0 ? 0 : 1;
+}
+
+/*
+ * Prepare alternate object database registry.
+ *
+ * The variable alt_odb_list points at the list of struct
+ * object_directory. The elements on this list come from
+ * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
+ * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
+ * whose contents is similar to that environment variable but can be
+ * LF separated. Its base points at a statically allocated buffer that
+ * contains "/the/directory/corresponding/to/.git/objects/...", while
+ * its name points just after the slash at the end of ".git/objects/"
+ * in the example above, and has enough space to hold all hex characters
+ * of the object ID, an extra slash for the first level indirection, and
+ * the terminating NUL.
+ */
+static void read_info_alternates(struct repository *r,
+ const char *relative_base,
+ int depth);
+static int link_alt_odb_entry(struct repository *r, const struct strbuf *entry,
+ const char *relative_base, int depth, const char *normalized_objdir)
+{
+ struct object_directory *ent;
+ struct strbuf pathbuf = STRBUF_INIT;
+ khiter_t pos;
+
+ if (!is_absolute_path(entry->buf) && relative_base) {
+ strbuf_realpath(&pathbuf, relative_base, 1);
+ strbuf_addch(&pathbuf, '/');
+ }
+ strbuf_addbuf(&pathbuf, entry);
+
+ if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
+ error(_("unable to normalize alternate object path: %s"),
+ pathbuf.buf);
+ strbuf_release(&pathbuf);
+ return -1;
+ }
+
+ /*
+ * The trailing slash after the directory name is given by
+ * this function at the end. Remove duplicates.
+ */
+ while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
+ strbuf_setlen(&pathbuf, pathbuf.len - 1);
+
+ if (!alt_odb_usable(r->objects, &pathbuf, normalized_objdir, &pos)) {
+ strbuf_release(&pathbuf);
+ return -1;
+ }
+
+ CALLOC_ARRAY(ent, 1);
+ /* pathbuf.buf is already in r->objects->odb_by_path */
+ ent->path = strbuf_detach(&pathbuf, NULL);
+
+ /* add the alternate entry */
+ *r->objects->odb_tail = ent;
+ r->objects->odb_tail = &(ent->next);
+ ent->next = NULL;
+ assert(r->objects->odb_by_path);
+ kh_value(r->objects->odb_by_path, pos) = ent;
+
+ /* recursively add alternates */
+ read_info_alternates(r, ent->path, depth + 1);
+
+ return 0;
+}
+
+static const char *parse_alt_odb_entry(const char *string,
+ int sep,
+ struct strbuf *out)
+{
+ const char *end;
+
+ strbuf_reset(out);
+
+ if (*string == '#') {
+ /* comment; consume up to next separator */
+ end = strchrnul(string, sep);
+ } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
+ /*
+ * quoted path; unquote_c_style has copied the
+ * data for us and set "end". Broken quoting (e.g.,
+ * an entry that doesn't end with a quote) falls
+ * back to the unquoted case below.
+ */
+ } else {
+ /* normal, unquoted path */
+ end = strchrnul(string, sep);
+ strbuf_add(out, string, end - string);
+ }
+
+ if (*end)
+ end++;
+ return end;
+}
+
+static void link_alt_odb_entries(struct repository *r, const char *alt,
+ int sep, const char *relative_base, int depth)
+{
+ struct strbuf objdirbuf = STRBUF_INIT;
+ struct strbuf entry = STRBUF_INIT;
+
+ if (!alt || !*alt)
+ return;
+
+ if (depth > 5) {
+ error(_("%s: ignoring alternate object stores, nesting too deep"),
+ relative_base);
+ return;
+ }
+
+ strbuf_add_absolute_path(&objdirbuf, r->objects->odb->path);
+ if (strbuf_normalize_path(&objdirbuf) < 0)
+ die(_("unable to normalize object directory: %s"),
+ objdirbuf.buf);
+
+ while (*alt) {
+ alt = parse_alt_odb_entry(alt, sep, &entry);
+ if (!entry.len)
+ continue;
+ link_alt_odb_entry(r, &entry,
+ relative_base, depth, objdirbuf.buf);
+ }
+ strbuf_release(&entry);
+ strbuf_release(&objdirbuf);
+}
+
+static void read_info_alternates(struct repository *r,
+ const char *relative_base,
+ int depth)
+{
+ char *path;
+ struct strbuf buf = STRBUF_INIT;
+
+ path = xstrfmt("%s/info/alternates", relative_base);
+ if (strbuf_read_file(&buf, path, 1024) < 0) {
+ warn_on_fopen_errors(path);
+ free(path);
+ return;
+ }
+
+ link_alt_odb_entries(r, buf.buf, '\n', relative_base, depth);
+ strbuf_release(&buf);
+ free(path);
+}
+
+void add_to_alternates_file(const char *reference)
+{
+ struct lock_file lock = LOCK_INIT;
+ char *alts = git_pathdup("objects/info/alternates");
+ FILE *in, *out;
+ int found = 0;
+
+ hold_lock_file_for_update(&lock, alts, LOCK_DIE_ON_ERROR);
+ out = fdopen_lock_file(&lock, "w");
+ if (!out)
+ die_errno(_("unable to fdopen alternates lockfile"));
+
+ in = fopen(alts, "r");
+ if (in) {
+ struct strbuf line = STRBUF_INIT;
+
+ while (strbuf_getline(&line, in) != EOF) {
+ if (!strcmp(reference, line.buf)) {
+ found = 1;
+ break;
+ }
+ fprintf_or_die(out, "%s\n", line.buf);
+ }
+
+ strbuf_release(&line);
+ fclose(in);
+ }
+ else if (errno != ENOENT)
+ die_errno(_("unable to read alternates file"));
+
+ if (found) {
+ rollback_lock_file(&lock);
+ } else {
+ fprintf_or_die(out, "%s\n", reference);
+ if (commit_lock_file(&lock))
+ die_errno(_("unable to move new alternates file into place"));
+ if (the_repository->objects->loaded_alternates)
+ link_alt_odb_entries(the_repository, reference,
+ '\n', NULL, 0);
+ }
+ free(alts);
+}
+
+void add_to_alternates_memory(const char *reference)
+{
+ /*
+ * Make sure alternates are initialized, or else our entry may be
+ * overwritten when they are.
+ */
+ prepare_alt_odb(the_repository);
+
+ link_alt_odb_entries(the_repository, reference,
+ '\n', NULL, 0);
+}
+
+/*
+ * Compute the exact path an alternate is at and returns it. In case of
+ * error NULL is returned and the human readable error is added to `err`
+ * `path` may be relative and should point to $GIT_DIR.
+ * `err` must not be null.
+ */
+char *compute_alternate_path(const char *path, struct strbuf *err)
+{
+ char *ref_git = NULL;
+ const char *repo;
+ int seen_error = 0;
+
+ ref_git = real_pathdup(path, 0);
+ if (!ref_git) {
+ seen_error = 1;
+ strbuf_addf(err, _("path '%s' does not exist"), path);
+ goto out;
+ }
+
+ repo = read_gitfile(ref_git);
+ if (!repo)
+ repo = read_gitfile(mkpath("%s/.git", ref_git));
+ if (repo) {
+ free(ref_git);
+ ref_git = xstrdup(repo);
+ }
+
+ if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
+ char *ref_git_git = mkpathdup("%s/.git", ref_git);
+ free(ref_git);
+ ref_git = ref_git_git;
+ } else if (!is_directory(mkpath("%s/objects", ref_git))) {
+ struct strbuf sb = STRBUF_INIT;
+ seen_error = 1;
+ if (get_common_dir(&sb, ref_git)) {
+ strbuf_addf(err,
+ _("reference repository '%s' as a linked "
+ "checkout is not supported yet."),
+ path);
+ goto out;
+ }
+
+ strbuf_addf(err, _("reference repository '%s' is not a "
+ "local repository."), path);
+ goto out;
+ }
+
+ if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
+ strbuf_addf(err, _("reference repository '%s' is shallow"),
+ path);
+ seen_error = 1;
+ goto out;
+ }
+
+ if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
+ strbuf_addf(err,
+ _("reference repository '%s' is grafted"),
+ path);
+ seen_error = 1;
+ goto out;
+ }
+
+out:
+ if (seen_error) {
+ FREE_AND_NULL(ref_git);
+ }
+
+ return ref_git;
+}
+
+static void fill_alternate_refs_command(struct child_process *cmd,
+ const char *repo_path)
+{
+ const char *value;
+
+ if (!git_config_get_value("core.alternateRefsCommand", &value)) {
+ cmd->use_shell = 1;
+
+ strvec_push(&cmd->args, value);
+ strvec_push(&cmd->args, repo_path);
+ } else {
+ cmd->git_cmd = 1;
+
+ strvec_pushf(&cmd->args, "--git-dir=%s", repo_path);
+ strvec_push(&cmd->args, "for-each-ref");
+ strvec_push(&cmd->args, "--format=%(objectname)");
+
+ if (!git_config_get_value("core.alternateRefsPrefixes", &value)) {
+ strvec_push(&cmd->args, "--");
+ strvec_split(&cmd->args, value);
+ }
+ }
+
+ cmd->env = local_repo_env;
+ cmd->out = -1;
+}
+
+static void read_alternate_refs(const char *path,
+ alternate_ref_fn *cb,
+ void *data)
+{
+ struct child_process cmd = CHILD_PROCESS_INIT;
+ struct strbuf line = STRBUF_INIT;
+ FILE *fh;
+
+ fill_alternate_refs_command(&cmd, path);
+
+ if (start_command(&cmd))
+ return;
+
+ fh = xfdopen(cmd.out, "r");
+ while (strbuf_getline_lf(&line, fh) != EOF) {
+ struct object_id oid;
+ const char *p;
+
+ if (parse_oid_hex(line.buf, &oid, &p) || *p) {
+ warning(_("invalid line while parsing alternate refs: %s"),
+ line.buf);
+ break;
+ }
+
+ cb(&oid, data);
+ }
+
+ fclose(fh);
+ finish_command(&cmd);
+ strbuf_release(&line);
+}
+
+struct alternate_refs_data {
+ alternate_ref_fn *fn;
+ void *data;
+};
+
+static int refs_from_alternate_cb(struct object_directory *e,
+ void *data)
+{
+ struct strbuf path = STRBUF_INIT;
+ size_t base_len;
+ struct alternate_refs_data *cb = data;
+
+ if (!strbuf_realpath(&path, e->path, 0))
+ goto out;
+ if (!strbuf_strip_suffix(&path, "/objects"))
+ goto out;
+ base_len = path.len;
+
+ /* Is this a git repository with refs? */
+ strbuf_addstr(&path, "/refs");
+ if (!is_directory(path.buf))
+ goto out;
+ strbuf_setlen(&path, base_len);
+
+ read_alternate_refs(path.buf, cb->fn, cb->data);
+
+out:
+ strbuf_release(&path);
+ return 0;
+}
+
+void for_each_alternate_ref(alternate_ref_fn fn, void *data)
+{
+ struct alternate_refs_data cb;
+ cb.fn = fn;
+ cb.data = data;
+ foreach_alt_odb(refs_from_alternate_cb, &cb);
+}
+
+int foreach_alt_odb(alt_odb_fn fn, void *cb)
+{
+ struct object_directory *ent;
+ int r = 0;
+
+ prepare_alt_odb(the_repository);
+ for (ent = the_repository->objects->odb->next; ent; ent = ent->next) {
+ r = fn(ent, cb);
+ if (r)
+ break;
+ }
+ return r;
+}
+
+void prepare_alt_odb(struct repository *r)
+{
+ if (r->objects->loaded_alternates)
+ return;
+
+ link_alt_odb_entries(r, r->objects->alternate_db, PATH_SEP, NULL, 0);
+
+ read_info_alternates(r, r->objects->odb->path, 0);
+ r->objects->loaded_alternates = 1;
+}
+
+/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
+static int freshen_file(const char *fn)
+{
+ return !utime(fn, NULL);
+}
+
+/*
+ * All of the check_and_freshen functions return 1 if the file exists and was
+ * freshened (if freshening was requested), 0 otherwise. If they return
+ * 0, you should not assume that it is safe to skip a write of the object (it
+ * either does not exist on disk, or has a stale mtime and may be subject to
+ * pruning).
+ */
+int check_and_freshen_file(const char *fn, int freshen)
+{
+ if (access(fn, F_OK))
+ return 0;
+ if (freshen && !freshen_file(fn))
+ return 0;
+ return 1;
+}
+
+static int check_and_freshen_odb(struct object_directory *odb,
+ const struct object_id *oid,
+ int freshen)
+{
+ static struct strbuf path = STRBUF_INIT;
+ odb_loose_path(odb, &path, oid);
+ return check_and_freshen_file(path.buf, freshen);
+}
+
+static int check_and_freshen_local(const struct object_id *oid, int freshen)
+{
+ return check_and_freshen_odb(the_repository->objects->odb, oid, freshen);
+}
+
+static int check_and_freshen_nonlocal(const struct object_id *oid, int freshen)
+{
+ struct object_directory *odb;
+
+ prepare_alt_odb(the_repository);
+ for (odb = the_repository->objects->odb->next; odb; odb = odb->next) {
+ if (check_and_freshen_odb(odb, oid, freshen))
+ return 1;
+ }
+ return 0;
+}
+
+static int check_and_freshen(const struct object_id *oid, int freshen)
+{
+ return check_and_freshen_local(oid, freshen) ||
+ check_and_freshen_nonlocal(oid, freshen);
+}
+
+int has_loose_object_nonlocal(const struct object_id *oid)
+{
+ return check_and_freshen_nonlocal(oid, 0);
+}
+
+static int has_loose_object(const struct object_id *oid)
+{
+ return check_and_freshen(oid, 0);
+}
+
+static void mmap_limit_check(size_t length)
+{
+ static size_t limit = 0;
+ if (!limit) {
+ limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
+ if (!limit)
+ limit = SIZE_MAX;
+ }
+ if (length > limit)
+ die(_("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX),
+ (uintmax_t)length, (uintmax_t)limit);
+}
+
+void *xmmap_gently(void *start, size_t length,
+ int prot, int flags, int fd, off_t offset)
+{
+ void *ret;
+
+ mmap_limit_check(length);
+ ret = mmap(start, length, prot, flags, fd, offset);
+ if (ret == MAP_FAILED && !length)
+ ret = NULL;
+ return ret;
+}
+
+const char *mmap_os_err(void)
+{
+ static const char blank[] = "";
+#if defined(__linux__)
+ if (errno == ENOMEM) {
+ /* this continues an existing error message: */
+ static const char enomem[] =
+", check sys.vm.max_map_count and/or RLIMIT_DATA";
+ return enomem;
+ }
+#endif /* OS-specific bits */
+ return blank;
+}
+
+void *xmmap(void *start, size_t length,
+ int prot, int flags, int fd, off_t offset)
+{
+ void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
+ if (ret == MAP_FAILED)
+ die_errno(_("mmap failed%s"), mmap_os_err());
+ return ret;
+}
+
+/*
+ * With an in-core object data in "map", rehash it to make sure the
+ * object name actually matches "oid" to detect object corruption.
+ * With "map" == NULL, try reading the object named with "oid" using
+ * the streaming interface and rehash it to do the same.
+ */
+int check_object_signature(struct repository *r, const struct object_id *oid,
+ void *map, unsigned long size, const char *type)
+{
+ struct object_id real_oid;
+ enum object_type obj_type;
+ struct git_istream *st;
+ git_hash_ctx c;
+ char hdr[MAX_HEADER_LEN];
+ int hdrlen;
+
+ if (map) {
+ hash_object_file(r->hash_algo, map, size, type, &real_oid);
+ return !oideq(oid, &real_oid) ? -1 : 0;
+ }
+
+ st = open_istream(r, oid, &obj_type, &size, NULL);
+ if (!st)
+ return -1;
+
+ /* Generate the header */
+ hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX , type_name(obj_type), (uintmax_t)size) + 1;
+
+ /* Sha1.. */
+ r->hash_algo->init_fn(&c);
+ r->hash_algo->update_fn(&c, hdr, hdrlen);
+ for (;;) {
+ char buf[1024 * 16];
+ ssize_t readlen = read_istream(st, buf, sizeof(buf));
+
+ if (readlen < 0) {
+ close_istream(st);
+ return -1;
+ }
+ if (!readlen)
+ break;
+ r->hash_algo->update_fn(&c, buf, readlen);
+ }
+ r->hash_algo->final_oid_fn(&real_oid, &c);
+ close_istream(st);
+ return !oideq(oid, &real_oid) ? -1 : 0;
+}
+
+int git_open_cloexec(const char *name, int flags)
+{
+ int fd;
+ static int o_cloexec = O_CLOEXEC;
+
+ fd = open(name, flags | o_cloexec);
+ if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
+ /* Try again w/o O_CLOEXEC: the kernel might not support it */
+ o_cloexec &= ~O_CLOEXEC;
+ fd = open(name, flags | o_cloexec);
+ }
+
+#if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
+ {
+ static int fd_cloexec = FD_CLOEXEC;
+
+ if (!o_cloexec && 0 <= fd && fd_cloexec) {
+ /* Opened w/o O_CLOEXEC? try with fcntl(2) to add it */
+ int flags = fcntl(fd, F_GETFD);
+ if (fcntl(fd, F_SETFD, flags | fd_cloexec))
+ fd_cloexec = 0;
+ }
+ }
+#endif
+ return fd;
+}
+
+/*
+ * Find "oid" as a loose object in the local repository or in an alternate.
+ * Returns 0 on success, negative on failure.
+ *
+ * The "path" out-parameter will give the path of the object we found (if any).
+ * Note that it may point to static storage and is only valid until another
+ * call to stat_loose_object().
+ */
+static int stat_loose_object(struct repository *r, const struct object_id *oid,
+ struct stat *st, const char **path)
+{
+ struct object_directory *odb;
+ static struct strbuf buf = STRBUF_INIT;
+
+ prepare_alt_odb(r);
+ for (odb = r->objects->odb; odb; odb = odb->next) {
+ *path = odb_loose_path(odb, &buf, oid);
+ if (!lstat(*path, st))
+ return 0;
+ }
+
+ return -1;
+}
+
+/*
+ * Like stat_loose_object(), but actually open the object and return the
+ * descriptor. See the caveats on the "path" parameter above.
+ */
+static int open_loose_object(struct repository *r,
+ const struct object_id *oid, const char **path)
+{
+ int fd;
+ struct object_directory *odb;
+ int most_interesting_errno = ENOENT;
+ static struct strbuf buf = STRBUF_INIT;
+
+ prepare_alt_odb(r);
+ for (odb = r->objects->odb; odb; odb = odb->next) {
+ *path = odb_loose_path(odb, &buf, oid);
+ fd = git_open(*path);
+ if (fd >= 0)
+ return fd;
+
+ if (most_interesting_errno == ENOENT)
+ most_interesting_errno = errno;
+ }
+ errno = most_interesting_errno;
+ return -1;
+}
+
+static int quick_has_loose(struct repository *r,
+ const struct object_id *oid)
+{
+ struct object_directory *odb;
+
+ prepare_alt_odb(r);
+ for (odb = r->objects->odb; odb; odb = odb->next) {
+ if (oidtree_contains(odb_loose_cache(odb, oid), oid))
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * Map the loose object at "path" if it is not NULL, or the path found by
+ * searching for a loose object named "oid".
+ */
+static void *map_loose_object_1(struct repository *r, const char *path,
+ const struct object_id *oid, unsigned long *size)
+{
+ void *map;
+ int fd;
+
+ if (path)
+ fd = git_open(path);
+ else
+ fd = open_loose_object(r, oid, &path);
+ map = NULL;
+ if (fd >= 0) {
+ struct stat st;
+
+ if (!fstat(fd, &st)) {
+ *size = xsize_t(st.st_size);
+ if (!*size) {
+ /* mmap() is forbidden on empty files */
+ error(_("object file %s is empty"), path);
+ close(fd);
+ return NULL;
+ }
+ map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
+ }
+ close(fd);
+ }
+ return map;
+}
+
+void *map_loose_object(struct repository *r,
+ const struct object_id *oid,
+ unsigned long *size)
+{
+ return map_loose_object_1(r, NULL, oid, size);
+}
+
+static int unpack_loose_short_header(git_zstream *stream,
+ unsigned char *map, unsigned long mapsize,
+ void *buffer, unsigned long bufsiz)
+{
+ int ret;
+
+ /* Get the data stream */
+ memset(stream, 0, sizeof(*stream));
+ stream->next_in = map;
+ stream->avail_in = mapsize;
+ stream->next_out = buffer;
+ stream->avail_out = bufsiz;
+
+ git_inflate_init(stream);
+ obj_read_unlock();
+ ret = git_inflate(stream, 0);
+ obj_read_lock();
+
+ return ret;
+}
+
+int unpack_loose_header(git_zstream *stream,
+ unsigned char *map, unsigned long mapsize,
+ void *buffer, unsigned long bufsiz)
+{
+ int status = unpack_loose_short_header(stream, map, mapsize,
+ buffer, bufsiz);
+
+ if (status < Z_OK)
+ return status;
+
+ /* Make sure we have the terminating NUL */
+ if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
+ return -1;
+ return 0;
+}
+
+static int unpack_loose_header_to_strbuf(git_zstream *stream, unsigned char *map,
+ unsigned long mapsize, void *buffer,
+ unsigned long bufsiz, struct strbuf *header)
+{
+ int status;
+
+ status = unpack_loose_short_header(stream, map, mapsize, buffer, bufsiz);
+ if (status < Z_OK)
+ return -1;
+
+ /*
+ * Check if entire header is unpacked in the first iteration.
+ */
+ if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
+ return 0;
+
+ /*
+ * buffer[0..bufsiz] was not large enough. Copy the partial
+ * result out to header, and then append the result of further
+ * reading the stream.
+ */
+ strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
+ stream->next_out = buffer;
+ stream->avail_out = bufsiz;
+
+ do {
+ obj_read_unlock();
+ status = git_inflate(stream, 0);
+ obj_read_lock();
+ strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
+ if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
+ return 0;
+ stream->next_out = buffer;
+ stream->avail_out = bufsiz;
+ } while (status != Z_STREAM_END);
+ return -1;
+}
+
+static void *unpack_loose_rest(git_zstream *stream,
+ void *buffer, unsigned long size,
+ const struct object_id *oid)
+{
+ int bytes = strlen(buffer) + 1;
+ unsigned char *buf = xmallocz(size);
+ unsigned long n;
+ int status = Z_OK;
+
+ n = stream->total_out - bytes;
+ if (n > size)
+ n = size;
+ memcpy(buf, (char *) buffer + bytes, n);
+ bytes = n;
+ if (bytes <= size) {
+ /*
+ * The above condition must be (bytes <= size), not
+ * (bytes < size). In other words, even though we
+ * expect no more output and set avail_out to zero,
+ * the input zlib stream may have bytes that express
+ * "this concludes the stream", and we *do* want to
+ * eat that input.
+ *
+ * Otherwise we would not be able to test that we
+ * consumed all the input to reach the expected size;
+ * we also want to check that zlib tells us that all
+ * went well with status == Z_STREAM_END at the end.
+ */
+ stream->next_out = buf + bytes;
+ stream->avail_out = size - bytes;
+ while (status == Z_OK) {
+ obj_read_unlock();
+ status = git_inflate(stream, Z_FINISH);
+ obj_read_lock();
+ }
+ }
+ if (status == Z_STREAM_END && !stream->avail_in) {
+ git_inflate_end(stream);
+ return buf;
+ }
+
+ if (status < 0)
+ error(_("corrupt loose object '%s'"), oid_to_hex(oid));
+ else if (stream->avail_in)
+ error(_("garbage at end of loose object '%s'"),
+ oid_to_hex(oid));
+ free(buf);
+ return NULL;
+}
+
+/*
+ * We used to just use "sscanf()", but that's actually way
+ * too permissive for what we want to check. So do an anal
+ * object header parse by hand.
+ */
+static int parse_loose_header_extended(const char *hdr, struct object_info *oi,
+ unsigned int flags)
+{
+ const char *type_buf = hdr;
+ unsigned long size;
+ int type, type_len = 0;
+
+ /*
+ * The type can be of any size but is followed by
+ * a space.
+ */
+ for (;;) {
+ char c = *hdr++;
+ if (!c)
+ return -1;
+ if (c == ' ')
+ break;
+ type_len++;
+ }
+
+ type = type_from_string_gently(type_buf, type_len, 1);
+ if (oi->type_name)
+ strbuf_add(oi->type_name, type_buf, type_len);
+ /*
+ * Set type to 0 if its an unknown object and
+ * we're obtaining the type using '--allow-unknown-type'
+ * option.
+ */
+ if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
+ type = 0;
+ else if (type < 0)
+ die(_("invalid object type"));
+ if (oi->typep)
+ *oi->typep = type;
+
+ /*
+ * The length must follow immediately, and be in canonical
+ * decimal format (ie "010" is not valid).
+ */
+ size = *hdr++ - '0';
+ if (size > 9)
+ return -1;
+ if (size) {
+ for (;;) {
+ unsigned long c = *hdr - '0';
+ if (c > 9)
+ break;
+ hdr++;
+ size = size * 10 + c;
+ }
+ }
+
+ if (oi->sizep)
+ *oi->sizep = size;
+
+ /*
+ * The length must be followed by a zero byte
+ */
+ return *hdr ? -1 : type;
+}
+
+int parse_loose_header(const char *hdr, unsigned long *sizep)
+{
+ struct object_info oi = OBJECT_INFO_INIT;
+
+ oi.sizep = sizep;
+ return parse_loose_header_extended(hdr, &oi, 0);
+}
+
+static int loose_object_info(struct repository *r,
+ const struct object_id *oid,
+ struct object_info *oi, int flags)
+{
+ int status = 0;
+ unsigned long mapsize;
+ void *map;
+ git_zstream stream;
+ char hdr[MAX_HEADER_LEN];
+ struct strbuf hdrbuf = STRBUF_INIT;
+ unsigned long size_scratch;
+
+ if (oi->delta_base_oid)
+ oidclr(oi->delta_base_oid);
+
+ /*
+ * If we don't care about type or size, then we don't
+ * need to look inside the object at all. Note that we
+ * do not optimize out the stat call, even if the
+ * caller doesn't care about the disk-size, since our
+ * return value implicitly indicates whether the
+ * object even exists.
+ */
+ if (!oi->typep && !oi->type_name && !oi->sizep && !oi->contentp) {
+ const char *path;
+ struct stat st;
+ if (!oi->disk_sizep && (flags & OBJECT_INFO_QUICK))
+ return quick_has_loose(r, oid) ? 0 : -1;
+ if (stat_loose_object(r, oid, &st, &path) < 0)
+ return -1;
+ if (oi->disk_sizep)
+ *oi->disk_sizep = st.st_size;
+ return 0;
+ }
+
+ map = map_loose_object(r, oid, &mapsize);
+ if (!map)
+ return -1;
+
+ if (!oi->sizep)
+ oi->sizep = &size_scratch;
+
+ if (oi->disk_sizep)
+ *oi->disk_sizep = mapsize;
+ if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
+ if (unpack_loose_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
+ status = error(_("unable to unpack %s header with --allow-unknown-type"),
+ oid_to_hex(oid));
+ } else if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
+ status = error(_("unable to unpack %s header"),
+ oid_to_hex(oid));
+ if (status < 0)
+ ; /* Do nothing */
+ else if (hdrbuf.len) {
+ if ((status = parse_loose_header_extended(hdrbuf.buf, oi, flags)) < 0)
+ status = error(_("unable to parse %s header with --allow-unknown-type"),
+ oid_to_hex(oid));
+ } else if ((status = parse_loose_header_extended(hdr, oi, flags)) < 0)
+ status = error(_("unable to parse %s header"), oid_to_hex(oid));
+
+ if (status >= 0 && oi->contentp) {
+ *oi->contentp = unpack_loose_rest(&stream, hdr,
+ *oi->sizep, oid);
+ if (!*oi->contentp) {
+ git_inflate_end(&stream);
+ status = -1;
+ }
+ } else
+ git_inflate_end(&stream);
+
+ munmap(map, mapsize);
+ if (status && oi->typep)
+ *oi->typep = status;
+ if (oi->sizep == &size_scratch)
+ oi->sizep = NULL;
+ strbuf_release(&hdrbuf);
+ oi->whence = OI_LOOSE;
+ return (status < 0) ? status : 0;
+}
+
+int obj_read_use_lock = 0;
+pthread_mutex_t obj_read_mutex;
+
+void enable_obj_read_lock(void)
+{
+ if (obj_read_use_lock)
+ return;
+
+ obj_read_use_lock = 1;
+ init_recursive_mutex(&obj_read_mutex);
+}
+
+void disable_obj_read_lock(void)
+{
+ if (!obj_read_use_lock)
+ return;
+
+ obj_read_use_lock = 0;
+ pthread_mutex_destroy(&obj_read_mutex);
+}
+
+int fetch_if_missing = 1;
+
+static int do_oid_object_info_extended(struct repository *r,
+ const struct object_id *oid,
+ struct object_info *oi, unsigned flags)
+{
+ static struct object_info blank_oi = OBJECT_INFO_INIT;
+ struct cached_object *co;
+ struct pack_entry e;
+ int rtype;
+ const struct object_id *real = oid;
+ int already_retried = 0;
+
+
+ if (flags & OBJECT_INFO_LOOKUP_REPLACE)
+ real = lookup_replace_object(r, oid);
+
+ if (is_null_oid(real))
+ return -1;
+
+ if (!oi)
+ oi = &blank_oi;
+
+ co = find_cached_object(real);
+ if (co) {
+ if (oi->typep)
+ *(oi->typep) = co->type;
+ if (oi->sizep)
+ *(oi->sizep) = co->size;
+ if (oi->disk_sizep)
+ *(oi->disk_sizep) = 0;
+ if (oi->delta_base_oid)
+ oidclr(oi->delta_base_oid);
+ if (oi->type_name)
+ strbuf_addstr(oi->type_name, type_name(co->type));
+ if (oi->contentp)
+ *oi->contentp = xmemdupz(co->buf, co->size);
+ oi->whence = OI_CACHED;
+ return 0;
+ }
+
+ while (1) {
+ if (find_pack_entry(r, real, &e))
+ break;
+
+ if (flags & OBJECT_INFO_IGNORE_LOOSE)
+ return -1;
+
+ /* Most likely it's a loose object. */
+ if (!loose_object_info(r, real, oi, flags))
+ return 0;
+
+ /* Not a loose object; someone else may have just packed it. */
+ if (!(flags & OBJECT_INFO_QUICK)) {
+ reprepare_packed_git(r);
+ if (find_pack_entry(r, real, &e))
+ break;
+ }
+
+ /* Check if it is a missing object */
+ if (fetch_if_missing && repo_has_promisor_remote(r) &&
+ !already_retried &&
+ !(flags & OBJECT_INFO_SKIP_FETCH_OBJECT)) {
+ /*
+ * TODO Investigate checking promisor_remote_get_direct()
+ * TODO return value and stopping on error here.
+ */
+ promisor_remote_get_direct(r, real, 1);
+ already_retried = 1;
+ continue;
+ }
+
+ return -1;
+ }
+
+ if (oi == &blank_oi)
+ /*
+ * We know that the caller doesn't actually need the
+ * information below, so return early.
+ */
+ return 0;
+ rtype = packed_object_info(r, e.p, e.offset, oi);
+ if (rtype < 0) {
+ mark_bad_packed_object(e.p, real->hash);
+ return do_oid_object_info_extended(r, real, oi, 0);
+ } else if (oi->whence == OI_PACKED) {
+ oi->u.packed.offset = e.offset;
+ oi->u.packed.pack = e.p;
+ oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
+ rtype == OBJ_OFS_DELTA);
+ }
+
+ return 0;
+}
+
+int oid_object_info_extended(struct repository *r, const struct object_id *oid,
+ struct object_info *oi, unsigned flags)
+{
+ int ret;
+ obj_read_lock();
+ ret = do_oid_object_info_extended(r, oid, oi, flags);
+ obj_read_unlock();
+ return ret;
+}
+
+
+/* returns enum object_type or negative */
+int oid_object_info(struct repository *r,
+ const struct object_id *oid,
+ unsigned long *sizep)
+{
+ enum object_type type;
+ struct object_info oi = OBJECT_INFO_INIT;
+
+ oi.typep = &type;
+ oi.sizep = sizep;
+ if (oid_object_info_extended(r, oid, &oi,
+ OBJECT_INFO_LOOKUP_REPLACE) < 0)
+ return -1;
+ return type;
+}
+
+static void *read_object(struct repository *r,
+ const struct object_id *oid, enum object_type *type,
+ unsigned long *size)
+{
+ struct object_info oi = OBJECT_INFO_INIT;
+ void *content;
+ oi.typep = type;
+ oi.sizep = size;
+ oi.contentp = &content;
+
+ if (oid_object_info_extended(r, oid, &oi, 0) < 0)
+ return NULL;
+ return content;
+}
+
+int pretend_object_file(void *buf, unsigned long len, enum object_type type,
+ struct object_id *oid)
+{
+ struct cached_object *co;
+
+ hash_object_file(the_hash_algo, buf, len, type_name(type), oid);
+ if (has_object_file_with_flags(oid, OBJECT_INFO_QUICK | OBJECT_INFO_SKIP_FETCH_OBJECT) ||
+ find_cached_object(oid))
+ return 0;
+ ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
+ co = &cached_objects[cached_object_nr++];
+ co->size = len;
+ co->type = type;
+ co->buf = xmalloc(len);
+ memcpy(co->buf, buf, len);
+ oidcpy(&co->oid, oid);
+ return 0;
+}
+
+/*
+ * This function dies on corrupt objects; the callers who want to
+ * deal with them should arrange to call read_object() and give error
+ * messages themselves.
+ */
+void *read_object_file_extended(struct repository *r,
+ const struct object_id *oid,
+ enum object_type *type,
+ unsigned long *size,
+ int lookup_replace)
+{
+ void *data;
+ const struct packed_git *p;
+ const char *path;
+ struct stat st;
+ const struct object_id *repl = lookup_replace ?
+ lookup_replace_object(r, oid) : oid;
+
+ errno = 0;
+ data = read_object(r, repl, type, size);
+ if (data)
+ return data;
+
+ obj_read_lock();
+ if (errno && errno != ENOENT)
+ die_errno(_("failed to read object %s"), oid_to_hex(oid));
+
+ /* die if we replaced an object with one that does not exist */
+ if (repl != oid)
+ die(_("replacement %s not found for %s"),
+ oid_to_hex(repl), oid_to_hex(oid));
+
+ if (!stat_loose_object(r, repl, &st, &path))
+ die(_("loose object %s (stored in %s) is corrupt"),
+ oid_to_hex(repl), path);
+
+ if ((p = has_packed_and_bad(r, repl->hash)) != NULL)
+ die(_("packed object %s (stored in %s) is corrupt"),
+ oid_to_hex(repl), p->pack_name);
+ obj_read_unlock();
+
+ return NULL;
+}
+
+void *read_object_with_reference(struct repository *r,
+ const struct object_id *oid,
+ const char *required_type_name,
+ unsigned long *size,
+ struct object_id *actual_oid_return)
+{
+ enum object_type type, required_type;
+ void *buffer;
+ unsigned long isize;
+ struct object_id actual_oid;
+
+ required_type = type_from_string(required_type_name);
+ oidcpy(&actual_oid, oid);
+ while (1) {
+ int ref_length = -1;
+ const char *ref_type = NULL;
+
+ buffer = repo_read_object_file(r, &actual_oid, &type, &isize);
+ if (!buffer)
+ return NULL;
+ if (type == required_type) {
+ *size = isize;
+ if (actual_oid_return)
+ oidcpy(actual_oid_return, &actual_oid);
+ return buffer;
+ }
+ /* Handle references */
+ else if (type == OBJ_COMMIT)
+ ref_type = "tree ";
+ else if (type == OBJ_TAG)
+ ref_type = "object ";
+ else {
+ free(buffer);
+ return NULL;
+ }
+ ref_length = strlen(ref_type);
+
+ if (ref_length + the_hash_algo->hexsz > isize ||
+ memcmp(buffer, ref_type, ref_length) ||
+ get_oid_hex((char *) buffer + ref_length, &actual_oid)) {
+ free(buffer);
+ return NULL;
+ }
+ free(buffer);
+ /* Now we have the ID of the referred-to object in
+ * actual_oid. Check again. */
+ }
+}
+
+static void write_object_file_prepare(const struct git_hash_algo *algo,
+ const void *buf, unsigned long len,
+ const char *type, struct object_id *oid,
+ char *hdr, int *hdrlen)
+{
+ git_hash_ctx c;
+
+ /* Generate the header */
+ *hdrlen = xsnprintf(hdr, *hdrlen, "%s %"PRIuMAX , type, (uintmax_t)len)+1;
+
+ /* Sha1.. */
+ algo->init_fn(&c);
+ algo->update_fn(&c, hdr, *hdrlen);
+ algo->update_fn(&c, buf, len);
+ algo->final_oid_fn(oid, &c);
+}
+
+/*
+ * Move the just written object into its final resting place.
+ */
+int finalize_object_file(const char *tmpfile, const char *filename)
+{
+ int ret = 0;
+
+ if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
+ goto try_rename;
+ else if (link(tmpfile, filename))
+ ret = errno;
+
+ /*
+ * Coda hack - coda doesn't like cross-directory links,
+ * so we fall back to a rename, which will mean that it
+ * won't be able to check collisions, but that's not a
+ * big deal.
+ *
+ * The same holds for FAT formatted media.
+ *
+ * When this succeeds, we just return. We have nothing
+ * left to unlink.
+ */
+ if (ret && ret != EEXIST) {
+ try_rename:
+ if (!rename(tmpfile, filename))
+ goto out;
+ ret = errno;
+ }
+ unlink_or_warn(tmpfile);
+ if (ret) {
+ if (ret != EEXIST) {
+ return error_errno(_("unable to write file %s"), filename);
+ }
+ /* FIXME!!! Collision check here ? */
+ }
+
+out:
+ if (adjust_shared_perm(filename))
+ return error(_("unable to set permission to '%s'"), filename);
+ return 0;
+}
+
+static int write_buffer(int fd, const void *buf, size_t len)
+{
+ if (write_in_full(fd, buf, len) < 0)
+ return error_errno(_("file write error"));
+ return 0;
+}
+
+int hash_object_file(const struct git_hash_algo *algo, const void *buf,
+ unsigned long len, const char *type,
+ struct object_id *oid)
+{
+ char hdr[MAX_HEADER_LEN];
+ int hdrlen = sizeof(hdr);
+ write_object_file_prepare(algo, buf, len, type, oid, hdr, &hdrlen);
+ return 0;
+}
+
+/* Finalize a file on disk, and close it. */
+static void close_loose_object(int fd)
+{
+ if (fsync_object_files)
+ fsync_or_die(fd, "loose object file");
+ if (close(fd) != 0)
+ die_errno(_("error when closing loose object file"));
+}
+
+/* Size of directory component, including the ending '/' */
+static inline int directory_size(const char *filename)
+{
+ const char *s = strrchr(filename, '/');
+ if (!s)
+ return 0;
+ return s - filename + 1;
+}
+
+/*
+ * This creates a temporary file in the same directory as the final
+ * 'filename'
+ *
+ * We want to avoid cross-directory filename renames, because those
+ * can have problems on various filesystems (FAT, NFS, Coda).
+ */
+static int create_tmpfile(struct strbuf *tmp, const char *filename)
+{
+ int fd, dirlen = directory_size(filename);
+
+ strbuf_reset(tmp);
+ strbuf_add(tmp, filename, dirlen);
+ strbuf_addstr(tmp, "tmp_obj_XXXXXX");
+ fd = git_mkstemp_mode(tmp->buf, 0444);
+ if (fd < 0 && dirlen && errno == ENOENT) {
+ /*
+ * Make sure the directory exists; note that the contents
+ * of the buffer are undefined after mkstemp returns an
+ * error, so we have to rewrite the whole buffer from
+ * scratch.
+ */
+ strbuf_reset(tmp);
+ strbuf_add(tmp, filename, dirlen - 1);
+ if (mkdir(tmp->buf, 0777) && errno != EEXIST)
+ return -1;
+ if (adjust_shared_perm(tmp->buf))
+ return -1;
+
+ /* Try again */
+ strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
+ fd = git_mkstemp_mode(tmp->buf, 0444);
+ }
+ return fd;
+}
+
+static int write_loose_object(const struct object_id *oid, char *hdr,
+ int hdrlen, const void *buf, unsigned long len,
+ time_t mtime)
+{
+ int fd, ret;
+ unsigned char compressed[4096];
+ git_zstream stream;
+ git_hash_ctx c;
+ struct object_id parano_oid;
+ static struct strbuf tmp_file = STRBUF_INIT;
+ static struct strbuf filename = STRBUF_INIT;
+
+ loose_object_path(the_repository, &filename, oid);
+
+ fd = create_tmpfile(&tmp_file, filename.buf);
+ if (fd < 0) {
+ if (errno == EACCES)
+ return error(_("insufficient permission for adding an object to repository database %s"), get_object_directory());
+ else
+ return error_errno(_("unable to create temporary file"));
+ }
+
+ /* Set it up */
+ git_deflate_init(&stream, zlib_compression_level);
+ stream.next_out = compressed;
+ stream.avail_out = sizeof(compressed);
+ the_hash_algo->init_fn(&c);
+
+ /* First header.. */
+ stream.next_in = (unsigned char *)hdr;
+ stream.avail_in = hdrlen;
+ while (git_deflate(&stream, 0) == Z_OK)
+ ; /* nothing */
+ the_hash_algo->update_fn(&c, hdr, hdrlen);
+
+ /* Then the data itself.. */
+ stream.next_in = (void *)buf;
+ stream.avail_in = len;
+ do {
+ unsigned char *in0 = stream.next_in;
+ ret = git_deflate(&stream, Z_FINISH);
+ the_hash_algo->update_fn(&c, in0, stream.next_in - in0);
+ if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
+ die(_("unable to write loose object file"));
+ stream.next_out = compressed;
+ stream.avail_out = sizeof(compressed);
+ } while (ret == Z_OK);
+
+ if (ret != Z_STREAM_END)
+ die(_("unable to deflate new object %s (%d)"), oid_to_hex(oid),
+ ret);
+ ret = git_deflate_end_gently(&stream);
+ if (ret != Z_OK)
+ die(_("deflateEnd on object %s failed (%d)"), oid_to_hex(oid),
+ ret);
+ the_hash_algo->final_oid_fn(&parano_oid, &c);
+ if (!oideq(oid, &parano_oid))
+ die(_("confused by unstable object source data for %s"),
+ oid_to_hex(oid));
+
+ close_loose_object(fd);
+
+ if (mtime) {
+ struct utimbuf utb;
+ utb.actime = mtime;
+ utb.modtime = mtime;
+ if (utime(tmp_file.buf, &utb) < 0)
+ warning_errno(_("failed utime() on %s"), tmp_file.buf);
+ }
+
+ return finalize_object_file(tmp_file.buf, filename.buf);
+}
+
+static int freshen_loose_object(const struct object_id *oid)
+{
+ return check_and_freshen(oid, 1);
+}
+
+static int freshen_packed_object(const struct object_id *oid)
+{
+ struct pack_entry e;
+ if (!find_pack_entry(the_repository, oid, &e))
+ return 0;
+ if (e.p->freshened)
+ return 1;
+ if (!freshen_file(e.p->pack_name))
+ return 0;
+ e.p->freshened = 1;
+ return 1;
+}
+
+int write_object_file(const void *buf, unsigned long len, const char *type,
+ struct object_id *oid)
+{
+ char hdr[MAX_HEADER_LEN];
+ int hdrlen = sizeof(hdr);
+
+ /* Normally if we have it in the pack then we do not bother writing
+ * it out into .git/objects/??/?{38} file.
+ */
+ write_object_file_prepare(the_hash_algo, buf, len, type, oid, hdr,
+ &hdrlen);
+ if (freshen_packed_object(oid) || freshen_loose_object(oid))
+ return 0;
+ return write_loose_object(oid, hdr, hdrlen, buf, len, 0);
+}
+
+int hash_object_file_literally(const void *buf, unsigned long len,
+ const char *type, struct object_id *oid,
+ unsigned flags)
+{
+ char *header;
+ int hdrlen, status = 0;
+
+ /* type string, SP, %lu of the length plus NUL must fit this */
+ hdrlen = strlen(type) + MAX_HEADER_LEN;
+ header = xmalloc(hdrlen);
+ write_object_file_prepare(the_hash_algo, buf, len, type, oid, header,
+ &hdrlen);
+
+ if (!(flags & HASH_WRITE_OBJECT))
+ goto cleanup;
+ if (freshen_packed_object(oid) || freshen_loose_object(oid))
+ goto cleanup;
+ status = write_loose_object(oid, header, hdrlen, buf, len, 0);
+
+cleanup:
+ free(header);
+ return status;
+}
+
+int force_object_loose(const struct object_id *oid, time_t mtime)
+{
+ void *buf;
+ unsigned long len;
+ enum object_type type;
+ char hdr[MAX_HEADER_LEN];
+ int hdrlen;
+ int ret;
+
+ if (has_loose_object(oid))
+ return 0;
+ buf = read_object(the_repository, oid, &type, &len);
+ if (!buf)
+ return error(_("cannot read object for %s"), oid_to_hex(oid));
+ hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX , type_name(type), (uintmax_t)len) + 1;
+ ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime);
+ free(buf);
+
+ return ret;
+}
+
+int has_object(struct repository *r, const struct object_id *oid,
+ unsigned flags)
+{
+ int quick = !(flags & HAS_OBJECT_RECHECK_PACKED);
+ unsigned object_info_flags = OBJECT_INFO_SKIP_FETCH_OBJECT |
+ (quick ? OBJECT_INFO_QUICK : 0);
+
+ if (!startup_info->have_repository)
+ return 0;
+ return oid_object_info_extended(r, oid, NULL, object_info_flags) >= 0;
+}
+
+int repo_has_object_file_with_flags(struct repository *r,
+ const struct object_id *oid, int flags)
+{
+ if (!startup_info->have_repository)
+ return 0;
+ return oid_object_info_extended(r, oid, NULL, flags) >= 0;
+}
+
+int repo_has_object_file(struct repository *r,
+ const struct object_id *oid)
+{
+ return repo_has_object_file_with_flags(r, oid, 0);
+}
+
+static void check_tree(const void *buf, size_t size)
+{
+ struct tree_desc desc;
+ struct name_entry entry;
+
+ init_tree_desc(&desc, buf, size);
+ while (tree_entry(&desc, &entry))
+ /* do nothing
+ * tree_entry() will die() on malformed entries */
+ ;
+}
+
+static void check_commit(const void *buf, size_t size)
+{
+ struct commit c;
+ memset(&c, 0, sizeof(c));
+ if (parse_commit_buffer(the_repository, &c, buf, size, 0))
+ die(_("corrupt commit"));
+}
+
+static void check_tag(const void *buf, size_t size)
+{
+ struct tag t;
+ memset(&t, 0, sizeof(t));
+ if (parse_tag_buffer(the_repository, &t, buf, size))
+ die(_("corrupt tag"));
+}
+
+static int index_mem(struct index_state *istate,
+ struct object_id *oid, void *buf, size_t size,
+ enum object_type type,
+ const char *path, unsigned flags)
+{
+ int ret, re_allocated = 0;
+ int write_object = flags & HASH_WRITE_OBJECT;
+
+ if (!type)
+ type = OBJ_BLOB;
+
+ /*
+ * Convert blobs to git internal format
+ */
+ if ((type == OBJ_BLOB) && path) {
+ struct strbuf nbuf = STRBUF_INIT;
+ if (convert_to_git(istate, path, buf, size, &nbuf,
+ get_conv_flags(flags))) {
+ buf = strbuf_detach(&nbuf, &size);
+ re_allocated = 1;
+ }
+ }
+ if (flags & HASH_FORMAT_CHECK) {
+ if (type == OBJ_TREE)
+ check_tree(buf, size);
+ if (type == OBJ_COMMIT)
+ check_commit(buf, size);
+ if (type == OBJ_TAG)
+ check_tag(buf, size);
+ }
+
+ if (write_object)
+ ret = write_object_file(buf, size, type_name(type), oid);
+ else
+ ret = hash_object_file(the_hash_algo, buf, size,
+ type_name(type), oid);
+ if (re_allocated)
+ free(buf);
+ return ret;
+}
+
+static int index_stream_convert_blob(struct index_state *istate,
+ struct object_id *oid,
+ int fd,
+ const char *path,
+ unsigned flags)
+{
+ int ret;
+ const int write_object = flags & HASH_WRITE_OBJECT;
+ struct strbuf sbuf = STRBUF_INIT;
+
+ assert(path);
+ assert(would_convert_to_git_filter_fd(istate, path));
+
+ convert_to_git_filter_fd(istate, path, fd, &sbuf,
+ get_conv_flags(flags));
+
+ if (write_object)
+ ret = write_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
+ oid);
+ else
+ ret = hash_object_file(the_hash_algo, sbuf.buf, sbuf.len,
+ type_name(OBJ_BLOB), oid);
+ strbuf_release(&sbuf);
+ return ret;
+}
+
+static int index_pipe(struct index_state *istate, struct object_id *oid,
+ int fd, enum object_type type,
+ const char *path, unsigned flags)
+{
+ struct strbuf sbuf = STRBUF_INIT;
+ int ret;
+
+ if (strbuf_read(&sbuf, fd, 4096) >= 0)
+ ret = index_mem(istate, oid, sbuf.buf, sbuf.len, type, path, flags);
+ else
+ ret = -1;
+ strbuf_release(&sbuf);
+ return ret;
+}
+
+#define SMALL_FILE_SIZE (32*1024)
+
+static int index_core(struct index_state *istate,
+ struct object_id *oid, int fd, size_t size,
+ enum object_type type, const char *path,
+ unsigned flags)
+{
+ int ret;
+
+ if (!size) {
+ ret = index_mem(istate, oid, "", size, type, path, flags);
+ } else if (size <= SMALL_FILE_SIZE) {
+ char *buf = xmalloc(size);
+ ssize_t read_result = read_in_full(fd, buf, size);
+ if (read_result < 0)
+ ret = error_errno(_("read error while indexing %s"),
+ path ? path : "<unknown>");
+ else if (read_result != size)
+ ret = error(_("short read while indexing %s"),
+ path ? path : "<unknown>");
+ else
+ ret = index_mem(istate, oid, buf, size, type, path, flags);
+ free(buf);
+ } else {
+ void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+ ret = index_mem(istate, oid, buf, size, type, path, flags);
+ munmap(buf, size);
+ }
+ return ret;
+}
+
+/*
+ * This creates one packfile per large blob unless bulk-checkin
+ * machinery is "plugged".
+ *
+ * This also bypasses the usual "convert-to-git" dance, and that is on
+ * purpose. We could write a streaming version of the converting
+ * functions and insert that before feeding the data to fast-import
+ * (or equivalent in-core API described above). However, that is
+ * somewhat complicated, as we do not know the size of the filter
+ * result, which we need to know beforehand when writing a git object.
+ * Since the primary motivation for trying to stream from the working
+ * tree file and to avoid mmaping it in core is to deal with large
+ * binary blobs, they generally do not want to get any conversion, and
+ * callers should avoid this code path when filters are requested.
+ */
+static int index_stream(struct object_id *oid, int fd, size_t size,
+ enum object_type type, const char *path,
+ unsigned flags)
+{
+ return index_bulk_checkin(oid, fd, size, type, path, flags);
+}
+
+int index_fd(struct index_state *istate, struct object_id *oid,
+ int fd, struct stat *st,
+ enum object_type type, const char *path, unsigned flags)
+{
+ int ret;
+
+ /*
+ * Call xsize_t() only when needed to avoid potentially unnecessary
+ * die() for large files.
+ */
+ if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(istate, path))
+ ret = index_stream_convert_blob(istate, oid, fd, path, flags);
+ else if (!S_ISREG(st->st_mode))
+ ret = index_pipe(istate, oid, fd, type, path, flags);
+ else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
+ (path && would_convert_to_git(istate, path)))
+ ret = index_core(istate, oid, fd, xsize_t(st->st_size),
+ type, path, flags);
+ else
+ ret = index_stream(oid, fd, xsize_t(st->st_size), type, path,
+ flags);
+ close(fd);
+ return ret;
+}
+
+int index_path(struct index_state *istate, struct object_id *oid,
+ const char *path, struct stat *st, unsigned flags)
+{
+ int fd;
+ struct strbuf sb = STRBUF_INIT;
+ int rc = 0;
+
+ switch (st->st_mode & S_IFMT) {
+ case S_IFREG:
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return error_errno("open(\"%s\")", path);
+ if (index_fd(istate, oid, fd, st, OBJ_BLOB, path, flags) < 0)
+ return error(_("%s: failed to insert into database"),
+ path);
+ break;
+ case S_IFLNK:
+ if (strbuf_readlink(&sb, path, st->st_size))
+ return error_errno("readlink(\"%s\")", path);
+ if (!(flags & HASH_WRITE_OBJECT))
+ hash_object_file(the_hash_algo, sb.buf, sb.len,
+ blob_type, oid);
+ else if (write_object_file(sb.buf, sb.len, blob_type, oid))
+ rc = error(_("%s: failed to insert into database"), path);
+ strbuf_release(&sb);
+ break;
+ case S_IFDIR:
+ return resolve_gitlink_ref(path, "HEAD", oid);
+ default:
+ return error(_("%s: unsupported file type"), path);
+ }
+ return rc;
+}
+
+int read_pack_header(int fd, struct pack_header *header)
+{
+ if (read_in_full(fd, header, sizeof(*header)) != sizeof(*header))
+ /* "eof before pack header was fully read" */
+ return PH_ERROR_EOF;
+
+ if (header->hdr_signature != htonl(PACK_SIGNATURE))
+ /* "protocol error (pack signature mismatch detected)" */
+ return PH_ERROR_PACK_SIGNATURE;
+ if (!pack_version_ok(header->hdr_version))
+ /* "protocol error (pack version unsupported)" */
+ return PH_ERROR_PROTOCOL;
+ return 0;
+}
+
+void assert_oid_type(const struct object_id *oid, enum object_type expect)
+{
+ enum object_type type = oid_object_info(the_repository, oid, NULL);
+ if (type < 0)
+ die(_("%s is not a valid object"), oid_to_hex(oid));
+ if (type != expect)
+ die(_("%s is not a valid '%s' object"), oid_to_hex(oid),
+ type_name(expect));
+}
+
+int for_each_file_in_obj_subdir(unsigned int subdir_nr,
+ struct strbuf *path,
+ each_loose_object_fn obj_cb,
+ each_loose_cruft_fn cruft_cb,
+ each_loose_subdir_fn subdir_cb,
+ void *data)
+{
+ size_t origlen, baselen;
+ DIR *dir;
+ struct dirent *de;
+ int r = 0;
+ struct object_id oid;
+
+ if (subdir_nr > 0xff)
+ BUG("invalid loose object subdirectory: %x", subdir_nr);
+
+ origlen = path->len;
+ strbuf_complete(path, '/');
+ strbuf_addf(path, "%02x", subdir_nr);
+
+ dir = opendir(path->buf);
+ if (!dir) {
+ if (errno != ENOENT)
+ r = error_errno(_("unable to open %s"), path->buf);
+ strbuf_setlen(path, origlen);
+ return r;
+ }
+
+ oid.hash[0] = subdir_nr;
+ strbuf_addch(path, '/');
+ baselen = path->len;
+
+ while ((de = readdir_skip_dot_and_dotdot(dir))) {
+ size_t namelen;
+
+ namelen = strlen(de->d_name);
+ strbuf_setlen(path, baselen);
+ strbuf_add(path, de->d_name, namelen);
+ if (namelen == the_hash_algo->hexsz - 2 &&
+ !hex_to_bytes(oid.hash + 1, de->d_name,
+ the_hash_algo->rawsz - 1)) {
+ oid_set_algo(&oid, the_hash_algo);
+ if (obj_cb) {
+ r = obj_cb(&oid, path->buf, data);
+ if (r)
+ break;
+ }
+ continue;
+ }
+
+ if (cruft_cb) {
+ r = cruft_cb(de->d_name, path->buf, data);
+ if (r)
+ break;
+ }
+ }
+ closedir(dir);
+
+ strbuf_setlen(path, baselen - 1);
+ if (!r && subdir_cb)
+ r = subdir_cb(subdir_nr, path->buf, data);
+
+ strbuf_setlen(path, origlen);
+
+ return r;
+}
+
+int for_each_loose_file_in_objdir_buf(struct strbuf *path,
+ each_loose_object_fn obj_cb,
+ each_loose_cruft_fn cruft_cb,
+ each_loose_subdir_fn subdir_cb,
+ void *data)
+{
+ int r = 0;
+ int i;
+
+ for (i = 0; i < 256; i++) {
+ r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
+ subdir_cb, data);
+ if (r)
+ break;
+ }
+
+ return r;
+}
+
+int for_each_loose_file_in_objdir(const char *path,
+ each_loose_object_fn obj_cb,
+ each_loose_cruft_fn cruft_cb,
+ each_loose_subdir_fn subdir_cb,
+ void *data)
+{
+ struct strbuf buf = STRBUF_INIT;
+ int r;
+
+ strbuf_addstr(&buf, path);
+ r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
+ subdir_cb, data);
+ strbuf_release(&buf);
+
+ return r;
+}
+
+int for_each_loose_object(each_loose_object_fn cb, void *data,
+ enum for_each_object_flags flags)
+{
+ struct object_directory *odb;
+
+ prepare_alt_odb(the_repository);
+ for (odb = the_repository->objects->odb; odb; odb = odb->next) {
+ int r = for_each_loose_file_in_objdir(odb->path, cb, NULL,
+ NULL, data);
+ if (r)
+ return r;
+
+ if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
+ break;
+ }
+
+ return 0;
+}
+
+static int append_loose_object(const struct object_id *oid, const char *path,
+ void *data)
+{
+ oidtree_insert(data, oid);
+ return 0;
+}
+
+struct oidtree *odb_loose_cache(struct object_directory *odb,
+ const struct object_id *oid)
+{
+ int subdir_nr = oid->hash[0];
+ struct strbuf buf = STRBUF_INIT;
+ size_t word_bits = bitsizeof(odb->loose_objects_subdir_seen[0]);
+ size_t word_index = subdir_nr / word_bits;
+ size_t mask = 1u << (subdir_nr % word_bits);
+ uint32_t *bitmap;
+
+ if (subdir_nr < 0 ||
+ subdir_nr >= bitsizeof(odb->loose_objects_subdir_seen))
+ BUG("subdir_nr out of range");
+
+ bitmap = &odb->loose_objects_subdir_seen[word_index];
+ if (*bitmap & mask)
+ return odb->loose_objects_cache;
+ if (!odb->loose_objects_cache) {
+ ALLOC_ARRAY(odb->loose_objects_cache, 1);
+ oidtree_init(odb->loose_objects_cache);
+ }
+ strbuf_addstr(&buf, odb->path);
+ for_each_file_in_obj_subdir(subdir_nr, &buf,
+ append_loose_object,
+ NULL, NULL,
+ odb->loose_objects_cache);
+ *bitmap |= mask;
+ strbuf_release(&buf);
+ return odb->loose_objects_cache;
+}
+
+void odb_clear_loose_cache(struct object_directory *odb)
+{
+ oidtree_clear(odb->loose_objects_cache);
+ FREE_AND_NULL(odb->loose_objects_cache);
+ memset(&odb->loose_objects_subdir_seen, 0,
+ sizeof(odb->loose_objects_subdir_seen));
+}
+
+static int check_stream_oid(git_zstream *stream,
+ const char *hdr,
+ unsigned long size,
+ const char *path,
+ const struct object_id *expected_oid)
+{
+ git_hash_ctx c;
+ struct object_id real_oid;
+ unsigned char buf[4096];
+ unsigned long total_read;
+ int status = Z_OK;
+
+ the_hash_algo->init_fn(&c);
+ the_hash_algo->update_fn(&c, hdr, stream->total_out);
+
+ /*
+ * We already read some bytes into hdr, but the ones up to the NUL
+ * do not count against the object's content size.
+ */
+ total_read = stream->total_out - strlen(hdr) - 1;
+
+ /*
+ * This size comparison must be "<=" to read the final zlib packets;
+ * see the comment in unpack_loose_rest for details.
+ */
+ while (total_read <= size &&
+ (status == Z_OK ||
+ (status == Z_BUF_ERROR && !stream->avail_out))) {
+ stream->next_out = buf;
+ stream->avail_out = sizeof(buf);
+ if (size - total_read < stream->avail_out)
+ stream->avail_out = size - total_read;
+ status = git_inflate(stream, Z_FINISH);
+ the_hash_algo->update_fn(&c, buf, stream->next_out - buf);
+ total_read += stream->next_out - buf;
+ }
+ git_inflate_end(stream);
+
+ if (status != Z_STREAM_END) {
+ error(_("corrupt loose object '%s'"), oid_to_hex(expected_oid));
+ return -1;
+ }
+ if (stream->avail_in) {
+ error(_("garbage at end of loose object '%s'"),
+ oid_to_hex(expected_oid));
+ return -1;
+ }
+
+ the_hash_algo->final_oid_fn(&real_oid, &c);
+ if (!oideq(expected_oid, &real_oid)) {
+ error(_("hash mismatch for %s (expected %s)"), path,
+ oid_to_hex(expected_oid));
+ return -1;
+ }
+
+ return 0;
+}
+
+int read_loose_object(const char *path,
+ const struct object_id *expected_oid,
+ enum object_type *type,
+ unsigned long *size,
+ void **contents)
+{
+ int ret = -1;
+ void *map = NULL;
+ unsigned long mapsize;
+ git_zstream stream;
+ char hdr[MAX_HEADER_LEN];
+
+ *contents = NULL;
+
+ map = map_loose_object_1(the_repository, path, NULL, &mapsize);
+ if (!map) {
+ error_errno(_("unable to mmap %s"), path);
+ goto out;
+ }
+
+ if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
+ error(_("unable to unpack header of %s"), path);
+ goto out;
+ }
+
+ *type = parse_loose_header(hdr, size);
+ if (*type < 0) {
+ error(_("unable to parse header of %s"), path);
+ git_inflate_end(&stream);
+ goto out;
+ }
+
+ if (*type == OBJ_BLOB && *size > big_file_threshold) {
+ if (check_stream_oid(&stream, hdr, *size, path, expected_oid) < 0)
+ goto out;
+ } else {
+ *contents = unpack_loose_rest(&stream, hdr, *size, expected_oid);
+ if (!*contents) {
+ error(_("unable to unpack contents of %s"), path);
+ git_inflate_end(&stream);
+ goto out;
+ }
+ if (check_object_signature(the_repository, expected_oid,
+ *contents, *size,
+ type_name(*type))) {
+ error(_("hash mismatch for %s (expected %s)"), path,
+ oid_to_hex(expected_oid));
+ free(*contents);
+ goto out;
+ }
+ }
+
+ ret = 0; /* everything checks out */
+
+out:
+ if (map)
+ munmap(map, mapsize);
+ return ret;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 14:05:25 +0000