diff options
Diffstat (limited to 'refs.c')
| -rw-r--r-- | refs.c | 3327 |
1 files changed, 3327 insertions, 0 deletions
diff --git a/refs.c b/refs.c new file mode 100644 index 0000000000..bfdbe718b7 --- /dev/null +++ b/refs.c @@ -0,0 +1,3327 @@ +/* + * The backend-independent part of the reference module. + */ + +#define USE_THE_REPOSITORY_VARIABLE +#define DISABLE_SIGN_COMPARE_WARNINGS + +#include "git-compat-util.h" +#include "advice.h" +#include "config.h" +#include "environment.h" +#include "strmap.h" +#include "gettext.h" +#include "hex.h" +#include "lockfile.h" +#include "iterator.h" +#include "refs.h" +#include "refs/refs-internal.h" +#include "run-command.h" +#include "hook.h" +#include "object-name.h" +#include "odb.h" +#include "object.h" +#include "path.h" +#include "submodule.h" +#include "worktree.h" +#include "strvec.h" +#include "repo-settings.h" +#include "setup.h" +#include "sigchain.h" +#include "date.h" +#include "commit.h" +#include "wildmatch.h" +#include "ident.h" + +/* + * List of all available backends + */ +static const struct ref_storage_be *refs_backends[] = { + [REF_STORAGE_FORMAT_FILES] = &refs_be_files, + [REF_STORAGE_FORMAT_REFTABLE] = &refs_be_reftable, +}; + +static const struct ref_storage_be *find_ref_storage_backend( + enum ref_storage_format ref_storage_format) +{ + if (ref_storage_format < ARRAY_SIZE(refs_backends)) + return refs_backends[ref_storage_format]; + return NULL; +} + +enum ref_storage_format ref_storage_format_by_name(const char *name) +{ + for (unsigned int i = 0; i < ARRAY_SIZE(refs_backends); i++) + if (refs_backends[i] && !strcmp(refs_backends[i]->name, name)) + return i; + return REF_STORAGE_FORMAT_UNKNOWN; +} + +const char *ref_storage_format_to_name(enum ref_storage_format ref_storage_format) +{ + const struct ref_storage_be *be = find_ref_storage_backend(ref_storage_format); + if (!be) + return "unknown"; + return be->name; +} + +/* + * How to handle various characters in refnames: + * 0: An acceptable character for refs + * 1: End-of-component + * 2: ., look for a preceding . to reject .. in refs + * 3: {, look for a preceding @ to reject @{ in refs + * 4: A bad character: ASCII control characters, and + * ":", "?", "[", "\", "^", "~", SP, or TAB + * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set + */ +static unsigned char refname_disposition[256] = { + 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, + 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, + 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4 +}; + +struct ref_namespace_info ref_namespace[] = { + [NAMESPACE_HEAD] = { + .ref = "HEAD", + .decoration = DECORATION_REF_HEAD, + .exact = 1, + }, + [NAMESPACE_BRANCHES] = { + .ref = "refs/heads/", + .decoration = DECORATION_REF_LOCAL, + }, + [NAMESPACE_TAGS] = { + .ref = "refs/tags/", + .decoration = DECORATION_REF_TAG, + }, + [NAMESPACE_REMOTE_REFS] = { + /* + * The default refspec for new remotes copies refs from + * refs/heads/ on the remote into refs/remotes/<remote>/. + * As such, "refs/remotes/" has special handling. + */ + .ref = "refs/remotes/", + .decoration = DECORATION_REF_REMOTE, + }, + [NAMESPACE_STASH] = { + /* + * The single ref "refs/stash" stores the latest stash. + * Older stashes can be found in the reflog. + */ + .ref = "refs/stash", + .exact = 1, + .decoration = DECORATION_REF_STASH, + }, + [NAMESPACE_REPLACE] = { + /* + * This namespace allows Git to act as if one object ID + * points to the content of another. Unlike the other + * ref namespaces, this one can be changed by the + * GIT_REPLACE_REF_BASE environment variable. This + * .namespace value will be overwritten in setup_git_env(). + */ + .ref = "refs/replace/", + .decoration = DECORATION_GRAFTED, + }, + [NAMESPACE_NOTES] = { + /* + * The refs/notes/commit ref points to the tip of a + * parallel commit history that adds metadata to commits + * in the normal history. This ref can be overwritten + * by the core.notesRef config variable or the + * GIT_NOTES_REFS environment variable. + */ + .ref = "refs/notes/commit", + .exact = 1, + }, + [NAMESPACE_PREFETCH] = { + /* + * Prefetch refs are written by the background 'fetch' + * maintenance task. It allows faster foreground fetches + * by advertising these previously-downloaded tips without + * updating refs/remotes/ without user intervention. + */ + .ref = "refs/prefetch/", + }, + [NAMESPACE_REWRITTEN] = { + /* + * Rewritten refs are used by the 'label' command in the + * sequencer. These are particularly useful during an + * interactive rebase that uses the 'merge' command. + */ + .ref = "refs/rewritten/", + }, +}; + +void update_ref_namespace(enum ref_namespace namespace, char *ref) +{ + struct ref_namespace_info *info = &ref_namespace[namespace]; + if (info->ref_updated) + free((char *)info->ref); + info->ref = ref; + info->ref_updated = 1; +} + +/* + * Try to read one refname component from the front of refname. + * Return the length of the component found, or -1 if the component is + * not legal. It is legal if it is something reasonable to have under + * ".git/refs/"; We do not like it if: + * + * - it begins with ".", or + * - it has double dots "..", or + * - it has ASCII control characters, or + * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or + * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or + * - it ends with a "/", or + * - it ends with ".lock", or + * - it contains a "@{" portion + * + * When sanitized is not NULL, instead of rejecting the input refname + * as an error, try to come up with a usable replacement for the input + * refname in it. + */ +static int check_refname_component(const char *refname, int *flags, + struct strbuf *sanitized) +{ + const char *cp; + char last = '\0'; + size_t component_start = 0; /* garbage - not a reasonable initial value */ + + if (sanitized) + component_start = sanitized->len; + + for (cp = refname; ; cp++) { + int ch = *cp & 255; + unsigned char disp = refname_disposition[ch]; + + if (sanitized && disp != 1) + strbuf_addch(sanitized, ch); + + switch (disp) { + case 1: + goto out; + case 2: + if (last == '.') { /* Refname contains "..". */ + if (sanitized) + /* collapse ".." to single "." */ + strbuf_setlen(sanitized, sanitized->len - 1); + else + return -1; + } + break; + case 3: + if (last == '@') { /* Refname contains "@{". */ + if (sanitized) + sanitized->buf[sanitized->len-1] = '-'; + else + return -1; + } + break; + case 4: + /* forbidden char */ + if (sanitized) + sanitized->buf[sanitized->len-1] = '-'; + else + return -1; + break; + case 5: + if (!(*flags & REFNAME_REFSPEC_PATTERN)) { + /* refspec can't be a pattern */ + if (sanitized) + sanitized->buf[sanitized->len-1] = '-'; + else + return -1; + } + + /* + * Unset the pattern flag so that we only accept + * a single asterisk for one side of refspec. + */ + *flags &= ~ REFNAME_REFSPEC_PATTERN; + break; + } + last = ch; + } +out: + if (cp == refname) + return 0; /* Component has zero length. */ + + if (refname[0] == '.') { /* Component starts with '.'. */ + if (sanitized) + sanitized->buf[component_start] = '-'; + else + return -1; + } + if (cp - refname >= LOCK_SUFFIX_LEN && + !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN)) { + if (!sanitized) + return -1; + /* Refname ends with ".lock". */ + while (strbuf_strip_suffix(sanitized, LOCK_SUFFIX)) { + /* try again in case we have .lock.lock */ + } + } + return cp - refname; +} + +static int check_or_sanitize_refname(const char *refname, int flags, + struct strbuf *sanitized) +{ + int component_len, component_count = 0; + + if (!strcmp(refname, "@")) { + /* Refname is a single character '@'. */ + if (sanitized) + strbuf_addch(sanitized, '-'); + else + return -1; + } + + while (1) { + if (sanitized && sanitized->len) + strbuf_complete(sanitized, '/'); + + /* We are at the start of a path component. */ + component_len = check_refname_component(refname, &flags, + sanitized); + if (sanitized && component_len == 0) + ; /* OK, omit empty component */ + else if (component_len <= 0) + return -1; + + component_count++; + if (refname[component_len] == '\0') + break; + /* Skip to next component. */ + refname += component_len + 1; + } + + if (refname[component_len - 1] == '.') { + /* Refname ends with '.'. */ + if (sanitized) + ; /* omit ending dot */ + else + return -1; + } + if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2) + return -1; /* Refname has only one component. */ + return 0; +} + +int check_refname_format(const char *refname, int flags) +{ + return check_or_sanitize_refname(refname, flags, NULL); +} + +int refs_fsck(struct ref_store *refs, struct fsck_options *o, + struct worktree *wt) +{ + return refs->be->fsck(refs, o, wt); +} + +void sanitize_refname_component(const char *refname, struct strbuf *out) +{ + if (check_or_sanitize_refname(refname, REFNAME_ALLOW_ONELEVEL, out)) + BUG("sanitizing refname '%s' check returned error", refname); +} + +int refname_is_safe(const char *refname) +{ + const char *rest; + + if (skip_prefix(refname, "refs/", &rest)) { + char *buf; + int result; + size_t restlen = strlen(rest); + + /* rest must not be empty, or start or end with "/" */ + if (!restlen || *rest == '/' || rest[restlen - 1] == '/') + return 0; + + /* + * Does the refname try to escape refs/? + * For example: refs/foo/../bar is safe but refs/foo/../../bar + * is not. + */ + buf = xmallocz(restlen); + result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest); + free(buf); + return result; + } + + do { + if (!isupper(*refname) && *refname != '_') + return 0; + refname++; + } while (*refname); + return 1; +} + +/* + * Return true if refname, which has the specified oid and flags, can + * be resolved to an object in the database. If the referred-to object + * does not exist, emit a warning and return false. + */ +int ref_resolves_to_object(const char *refname, + struct repository *repo, + const struct object_id *oid, + unsigned int flags) +{ + if (flags & REF_ISBROKEN) + return 0; + if (!odb_has_object(repo->objects, oid, + HAS_OBJECT_RECHECK_PACKED | HAS_OBJECT_FETCH_PROMISOR)) { + error(_("%s does not point to a valid object!"), refname); + return 0; + } + return 1; +} + +char *refs_resolve_refdup(struct ref_store *refs, + const char *refname, int resolve_flags, + struct object_id *oid, int *flags) +{ + const char *result; + + result = refs_resolve_ref_unsafe(refs, refname, resolve_flags, + oid, flags); + return xstrdup_or_null(result); +} + +/* The argument to for_each_filter_refs */ +struct for_each_ref_filter { + const char *pattern; + const char *prefix; + each_ref_fn *fn; + void *cb_data; +}; + +int refs_read_ref_full(struct ref_store *refs, const char *refname, + int resolve_flags, struct object_id *oid, int *flags) +{ + if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, + oid, flags)) + return 0; + return -1; +} + +int refs_read_ref(struct ref_store *refs, const char *refname, struct object_id *oid) +{ + return refs_read_ref_full(refs, refname, RESOLVE_REF_READING, oid, NULL); +} + +int refs_ref_exists(struct ref_store *refs, const char *refname) +{ + return !!refs_resolve_ref_unsafe(refs, refname, RESOLVE_REF_READING, + NULL, NULL); +} + +static int for_each_filter_refs(const char *refname, const char *referent, + const struct object_id *oid, + int flags, void *data) +{ + struct for_each_ref_filter *filter = data; + + if (wildmatch(filter->pattern, refname, 0)) + return 0; + if (filter->prefix) + skip_prefix(refname, filter->prefix, &refname); + return filter->fn(refname, referent, oid, flags, filter->cb_data); +} + +struct warn_if_dangling_data { + struct ref_store *refs; + FILE *fp; + const struct string_list *refnames; + const char *indent; + int dry_run; +}; + +static int warn_if_dangling_symref(const char *refname, const char *referent UNUSED, + const struct object_id *oid UNUSED, + int flags, void *cb_data) +{ + struct warn_if_dangling_data *d = cb_data; + const char *resolves_to, *msg; + + if (!(flags & REF_ISSYMREF)) + return 0; + + resolves_to = refs_resolve_ref_unsafe(d->refs, refname, 0, NULL, NULL); + if (!resolves_to + || !string_list_has_string(d->refnames, resolves_to)) { + return 0; + } + + msg = d->dry_run + ? _("%s%s will become dangling after %s is deleted\n") + : _("%s%s has become dangling after %s was deleted\n"); + fprintf(d->fp, msg, d->indent, refname, resolves_to); + return 0; +} + +void refs_warn_dangling_symrefs(struct ref_store *refs, FILE *fp, + const char *indent, int dry_run, + const struct string_list *refnames) +{ + struct warn_if_dangling_data data = { + .refs = refs, + .fp = fp, + .refnames = refnames, + .indent = indent, + .dry_run = dry_run, + }; + refs_for_each_rawref(refs, warn_if_dangling_symref, &data); +} + +int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data) +{ + return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data); +} + +int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data) +{ + return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data); +} + +int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data) +{ + return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data); +} + +int refs_head_ref_namespaced(struct ref_store *refs, each_ref_fn fn, void *cb_data) +{ + struct strbuf buf = STRBUF_INIT; + int ret = 0; + struct object_id oid; + int flag; + + strbuf_addf(&buf, "%sHEAD", get_git_namespace()); + if (!refs_read_ref_full(refs, buf.buf, RESOLVE_REF_READING, &oid, &flag)) + ret = fn(buf.buf, NULL, &oid, flag, cb_data); + strbuf_release(&buf); + + return ret; +} + +void normalize_glob_ref(struct string_list_item *item, const char *prefix, + const char *pattern) +{ + struct strbuf normalized_pattern = STRBUF_INIT; + + if (*pattern == '/') + BUG("pattern must not start with '/'"); + + if (prefix) + strbuf_addstr(&normalized_pattern, prefix); + else if (!starts_with(pattern, "refs/") && + strcmp(pattern, "HEAD")) + strbuf_addstr(&normalized_pattern, "refs/"); + /* + * NEEDSWORK: Special case other symrefs such as REBASE_HEAD, + * MERGE_HEAD, etc. + */ + + strbuf_addstr(&normalized_pattern, pattern); + strbuf_strip_suffix(&normalized_pattern, "/"); + + item->string = strbuf_detach(&normalized_pattern, NULL); + item->util = has_glob_specials(pattern) ? NULL : item->string; + strbuf_release(&normalized_pattern); +} + +int refs_for_each_glob_ref_in(struct ref_store *refs, each_ref_fn fn, + const char *pattern, const char *prefix, void *cb_data) +{ + struct strbuf real_pattern = STRBUF_INIT; + struct for_each_ref_filter filter; + int ret; + + if (!prefix && !starts_with(pattern, "refs/")) + strbuf_addstr(&real_pattern, "refs/"); + else if (prefix) + strbuf_addstr(&real_pattern, prefix); + strbuf_addstr(&real_pattern, pattern); + + if (!has_glob_specials(pattern)) { + /* Append implied '/' '*' if not present. */ + strbuf_complete(&real_pattern, '/'); + /* No need to check for '*', there is none. */ + strbuf_addch(&real_pattern, '*'); + } + + filter.pattern = real_pattern.buf; + filter.prefix = prefix; + filter.fn = fn; + filter.cb_data = cb_data; + ret = refs_for_each_ref(refs, for_each_filter_refs, &filter); + + strbuf_release(&real_pattern); + return ret; +} + +int refs_for_each_glob_ref(struct ref_store *refs, each_ref_fn fn, + const char *pattern, void *cb_data) +{ + return refs_for_each_glob_ref_in(refs, fn, pattern, NULL, cb_data); +} + +const char *prettify_refname(const char *name) +{ + if (skip_prefix(name, "refs/heads/", &name) || + skip_prefix(name, "refs/tags/", &name) || + skip_prefix(name, "refs/remotes/", &name)) + ; /* nothing */ + return name; +} + +static const char *ref_rev_parse_rules[] = { + "%.*s", + "refs/%.*s", + "refs/tags/%.*s", + "refs/heads/%.*s", + "refs/remotes/%.*s", + "refs/remotes/%.*s/HEAD", + NULL +}; + +#define NUM_REV_PARSE_RULES (ARRAY_SIZE(ref_rev_parse_rules) - 1) + +/* + * Is it possible that the caller meant full_name with abbrev_name? + * If so return a non-zero value to signal "yes"; the magnitude of + * the returned value gives the precedence used for disambiguation. + * + * If abbrev_name cannot mean full_name, return 0. + */ +int refname_match(const char *abbrev_name, const char *full_name) +{ + const char **p; + const int abbrev_name_len = strlen(abbrev_name); + const int num_rules = NUM_REV_PARSE_RULES; + + for (p = ref_rev_parse_rules; *p; p++) + if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) + return &ref_rev_parse_rules[num_rules] - p; + + return 0; +} + +/* + * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add + * the results to 'prefixes' + */ +void expand_ref_prefix(struct strvec *prefixes, const char *prefix) +{ + const char **p; + int len = strlen(prefix); + + for (p = ref_rev_parse_rules; *p; p++) + strvec_pushf(prefixes, *p, len, prefix); +} + +static const char default_branch_name_advice[] = N_( +"Using '%s' as the name for the initial branch. This default branch name\n" +"is subject to change. To configure the initial branch name to use in all\n" +"of your new repositories, which will suppress this warning, call:\n" +"\n" +"\tgit config --global init.defaultBranch <name>\n" +"\n" +"Names commonly chosen instead of 'master' are 'main', 'trunk' and\n" +"'development'. The just-created branch can be renamed via this command:\n" +"\n" +"\tgit branch -m <name>\n" +); + +char *repo_default_branch_name(struct repository *r, int quiet) +{ + const char *config_key = "init.defaultbranch"; + const char *config_display_key = "init.defaultBranch"; + char *ret = NULL, *full_ref; + const char *env = getenv("GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME"); + + if (env && *env) + ret = xstrdup(env); + else if (repo_config_get_string(r, config_key, &ret) < 0) + die(_("could not retrieve `%s`"), config_display_key); + + if (!ret) { + ret = xstrdup("master"); + if (!quiet) + advise_if_enabled(ADVICE_DEFAULT_BRANCH_NAME, + _(default_branch_name_advice), ret); + } + + full_ref = xstrfmt("refs/heads/%s", ret); + if (check_refname_format(full_ref, 0)) + die(_("invalid branch name: %s = %s"), config_display_key, ret); + free(full_ref); + + return ret; +} + +/* + * *string and *len will only be substituted, and *string returned (for + * later free()ing) if the string passed in is a magic short-hand form + * to name a branch. + */ +static char *substitute_branch_name(struct repository *r, + const char **string, int *len, + int nonfatal_dangling_mark) +{ + struct strbuf buf = STRBUF_INIT; + struct interpret_branch_name_options options = { + .nonfatal_dangling_mark = nonfatal_dangling_mark + }; + int ret = repo_interpret_branch_name(r, *string, *len, &buf, &options); + + if (ret == *len) { + size_t size; + *string = strbuf_detach(&buf, &size); + *len = size; + return (char *)*string; + } + + return NULL; +} + +void copy_branchname(struct strbuf *sb, const char *name, unsigned allowed) +{ + int len = strlen(name); + struct interpret_branch_name_options options = { + .allowed = allowed + }; + int used = repo_interpret_branch_name(the_repository, name, len, sb, + &options); + + if (used < 0) + used = 0; + strbuf_add(sb, name + used, len - used); +} + +int check_branch_ref(struct strbuf *sb, const char *name) +{ + if (startup_info->have_repository) + copy_branchname(sb, name, INTERPRET_BRANCH_LOCAL); + else + strbuf_addstr(sb, name); + + /* + * This splice must be done even if we end up rejecting the + * name; builtin/branch.c::copy_or_rename_branch() still wants + * to see what the name expanded to so that "branch -m" can be + * used as a tool to correct earlier mistakes. + */ + strbuf_splice(sb, 0, 0, "refs/heads/", 11); + + if (*name == '-' || + !strcmp(sb->buf, "refs/heads/HEAD")) + return -1; + + return check_refname_format(sb->buf, 0); +} + +int check_tag_ref(struct strbuf *sb, const char *name) +{ + if (name[0] == '-' || !strcmp(name, "HEAD")) + return -1; + + strbuf_reset(sb); + strbuf_addf(sb, "refs/tags/%s", name); + + return check_refname_format(sb->buf, 0); +} + +int repo_dwim_ref(struct repository *r, const char *str, int len, + struct object_id *oid, char **ref, int nonfatal_dangling_mark) +{ + char *last_branch = substitute_branch_name(r, &str, &len, + nonfatal_dangling_mark); + int refs_found = expand_ref(r, str, len, oid, ref); + free(last_branch); + return refs_found; +} + +int expand_ref(struct repository *repo, const char *str, int len, + struct object_id *oid, char **ref) +{ + const char **p, *r; + int refs_found = 0; + struct strbuf fullref = STRBUF_INIT; + + *ref = NULL; + for (p = ref_rev_parse_rules; *p; p++) { + struct object_id oid_from_ref; + struct object_id *this_result; + int flag; + struct ref_store *refs = get_main_ref_store(repo); + + this_result = refs_found ? &oid_from_ref : oid; + strbuf_reset(&fullref); + strbuf_addf(&fullref, *p, len, str); + r = refs_resolve_ref_unsafe(refs, fullref.buf, + RESOLVE_REF_READING, + this_result, &flag); + if (r) { + if (!refs_found++) + *ref = xstrdup(r); + if (!repo_settings_get_warn_ambiguous_refs(repo)) + break; + } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) { + warning(_("ignoring dangling symref %s"), fullref.buf); + } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) { + warning(_("ignoring broken ref %s"), fullref.buf); + } + } + strbuf_release(&fullref); + return refs_found; +} + +int repo_dwim_log(struct repository *r, const char *str, int len, + struct object_id *oid, char **log) +{ + struct ref_store *refs = get_main_ref_store(r); + char *last_branch = substitute_branch_name(r, &str, &len, 0); + const char **p; + int logs_found = 0; + struct strbuf path = STRBUF_INIT; + + *log = NULL; + for (p = ref_rev_parse_rules; *p; p++) { + struct object_id hash; + const char *ref, *it; + + strbuf_reset(&path); + strbuf_addf(&path, *p, len, str); + ref = refs_resolve_ref_unsafe(refs, path.buf, + RESOLVE_REF_READING, + oid ? &hash : NULL, NULL); + if (!ref) + continue; + if (refs_reflog_exists(refs, path.buf)) + it = path.buf; + else if (strcmp(ref, path.buf) && + refs_reflog_exists(refs, ref)) + it = ref; + else + continue; + if (!logs_found++) { + *log = xstrdup(it); + if (oid) + oidcpy(oid, &hash); + } + if (!repo_settings_get_warn_ambiguous_refs(r)) + break; + } + strbuf_release(&path); + free(last_branch); + return logs_found; +} + +int is_per_worktree_ref(const char *refname) +{ + return starts_with(refname, "refs/worktree/") || + starts_with(refname, "refs/bisect/") || + starts_with(refname, "refs/rewritten/"); +} + +int is_pseudo_ref(const char *refname) +{ + static const char * const pseudo_refs[] = { + "FETCH_HEAD", + "MERGE_HEAD", + }; + size_t i; + + for (i = 0; i < ARRAY_SIZE(pseudo_refs); i++) + if (!strcmp(refname, pseudo_refs[i])) + return 1; + + return 0; +} + +static int is_root_ref_syntax(const char *refname) +{ + const char *c; + + for (c = refname; *c; c++) { + if (!isupper(*c) && *c != '-' && *c != '_') + return 0; + } + + return 1; +} + +int is_root_ref(const char *refname) +{ + static const char *const irregular_root_refs[] = { + "HEAD", + "AUTO_MERGE", + "BISECT_EXPECTED_REV", + "NOTES_MERGE_PARTIAL", + "NOTES_MERGE_REF", + "MERGE_AUTOSTASH", + }; + size_t i; + + if (!is_root_ref_syntax(refname) || + is_pseudo_ref(refname)) + return 0; + + if (ends_with(refname, "_HEAD")) + return 1; + + for (i = 0; i < ARRAY_SIZE(irregular_root_refs); i++) + if (!strcmp(refname, irregular_root_refs[i])) + return 1; + + return 0; +} + +static int is_current_worktree_ref(const char *ref) { + return is_root_ref_syntax(ref) || is_per_worktree_ref(ref); +} + +enum ref_worktree_type parse_worktree_ref(const char *maybe_worktree_ref, + const char **worktree_name, int *worktree_name_length, + const char **bare_refname) +{ + const char *name_dummy; + int name_length_dummy; + const char *ref_dummy; + + if (!worktree_name) + worktree_name = &name_dummy; + if (!worktree_name_length) + worktree_name_length = &name_length_dummy; + if (!bare_refname) + bare_refname = &ref_dummy; + + if (skip_prefix(maybe_worktree_ref, "worktrees/", bare_refname)) { + const char *slash = strchr(*bare_refname, '/'); + + *worktree_name = *bare_refname; + if (!slash) { + *worktree_name_length = strlen(*worktree_name); + + /* This is an error condition, and the caller tell because the bare_refname is "" */ + *bare_refname = *worktree_name + *worktree_name_length; + return REF_WORKTREE_OTHER; + } + + *worktree_name_length = slash - *bare_refname; + *bare_refname = slash + 1; + + if (is_current_worktree_ref(*bare_refname)) + return REF_WORKTREE_OTHER; + } + + *worktree_name = NULL; + *worktree_name_length = 0; + + if (skip_prefix(maybe_worktree_ref, "main-worktree/", bare_refname) + && is_current_worktree_ref(*bare_refname)) + return REF_WORKTREE_MAIN; + + *bare_refname = maybe_worktree_ref; + if (is_current_worktree_ref(maybe_worktree_ref)) + return REF_WORKTREE_CURRENT; + + return REF_WORKTREE_SHARED; +} + +long get_files_ref_lock_timeout_ms(void) +{ + static int configured = 0; + + /* The default timeout is 100 ms: */ + static int timeout_ms = 100; + + if (!configured) { + repo_config_get_int(the_repository, "core.filesreflocktimeout", &timeout_ms); + configured = 1; + } + + return timeout_ms; +} + +int refs_delete_ref(struct ref_store *refs, const char *msg, + const char *refname, + const struct object_id *old_oid, + unsigned int flags) +{ + struct ref_transaction *transaction; + struct strbuf err = STRBUF_INIT; + + transaction = ref_store_transaction_begin(refs, 0, &err); + if (!transaction || + ref_transaction_delete(transaction, refname, old_oid, + NULL, flags, msg, &err) || + ref_transaction_commit(transaction, &err)) { + error("%s", err.buf); + ref_transaction_free(transaction); + strbuf_release(&err); + return 1; + } + ref_transaction_free(transaction); + strbuf_release(&err); + return 0; +} + +static void copy_reflog_msg(struct strbuf *sb, const char *msg) +{ + char c; + int wasspace = 1; + + while ((c = *msg++)) { + if (wasspace && isspace(c)) + continue; + wasspace = isspace(c); + if (wasspace) + c = ' '; + strbuf_addch(sb, c); + } + strbuf_rtrim(sb); +} + +static char *normalize_reflog_message(const char *msg) +{ + struct strbuf sb = STRBUF_INIT; + + if (msg && *msg) + copy_reflog_msg(&sb, msg); + return strbuf_detach(&sb, NULL); +} + +int should_autocreate_reflog(enum log_refs_config log_all_ref_updates, + const char *refname) +{ + switch (log_all_ref_updates) { + case LOG_REFS_ALWAYS: + return 1; + case LOG_REFS_NORMAL: + return starts_with(refname, "refs/heads/") || + starts_with(refname, "refs/remotes/") || + starts_with(refname, "refs/notes/") || + !strcmp(refname, "HEAD"); + default: + return 0; + } +} + +int is_branch(const char *refname) +{ + return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/"); +} + +struct read_ref_at_cb { + const char *refname; + timestamp_t at_time; + int cnt; + int reccnt; + struct object_id *oid; + int found_it; + + struct object_id ooid; + struct object_id noid; + int tz; + timestamp_t date; + char **msg; + timestamp_t *cutoff_time; + int *cutoff_tz; + int *cutoff_cnt; +}; + +static void set_read_ref_cutoffs(struct read_ref_at_cb *cb, + timestamp_t timestamp, int tz, const char *message) +{ + if (cb->msg) + *cb->msg = xstrdup(message); + if (cb->cutoff_time) + *cb->cutoff_time = timestamp; + if (cb->cutoff_tz) + *cb->cutoff_tz = tz; + if (cb->cutoff_cnt) + *cb->cutoff_cnt = cb->reccnt; +} + +static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid, + const char *email UNUSED, + timestamp_t timestamp, int tz, + const char *message, void *cb_data) +{ + struct read_ref_at_cb *cb = cb_data; + + cb->tz = tz; + cb->date = timestamp; + + if (timestamp <= cb->at_time || cb->cnt == 0) { + set_read_ref_cutoffs(cb, timestamp, tz, message); + /* + * we have not yet updated cb->[n|o]oid so they still + * hold the values for the previous record. + */ + if (!is_null_oid(&cb->ooid)) { + oidcpy(cb->oid, noid); + if (!oideq(&cb->ooid, noid)) + warning(_("log for ref %s has gap after %s"), + cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822))); + } + else if (cb->date == cb->at_time) + oidcpy(cb->oid, noid); + else if (!oideq(noid, cb->oid)) + warning(_("log for ref %s unexpectedly ended on %s"), + cb->refname, show_date(cb->date, cb->tz, + DATE_MODE(RFC2822))); + cb->reccnt++; + oidcpy(&cb->ooid, ooid); + oidcpy(&cb->noid, noid); + cb->found_it = 1; + return 1; + } + cb->reccnt++; + oidcpy(&cb->ooid, ooid); + oidcpy(&cb->noid, noid); + if (cb->cnt > 0) + cb->cnt--; + return 0; +} + +static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid, + const char *email UNUSED, + timestamp_t timestamp, int tz, + const char *message, void *cb_data) +{ + struct read_ref_at_cb *cb = cb_data; + + set_read_ref_cutoffs(cb, timestamp, tz, message); + oidcpy(cb->oid, ooid); + if (cb->at_time && is_null_oid(cb->oid)) + oidcpy(cb->oid, noid); + /* We just want the first entry */ + return 1; +} + +int read_ref_at(struct ref_store *refs, const char *refname, + unsigned int flags, timestamp_t at_time, int cnt, + struct object_id *oid, char **msg, + timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt) +{ + struct read_ref_at_cb cb; + + memset(&cb, 0, sizeof(cb)); + cb.refname = refname; + cb.at_time = at_time; + cb.cnt = cnt; + cb.msg = msg; + cb.cutoff_time = cutoff_time; + cb.cutoff_tz = cutoff_tz; + cb.cutoff_cnt = cutoff_cnt; + cb.oid = oid; + + refs_for_each_reflog_ent_reverse(refs, refname, read_ref_at_ent, &cb); + + if (!cb.reccnt) { + if (cnt == 0) { + /* + * The caller asked for ref@{0}, and we had no entries. + * It's a bit subtle, but in practice all callers have + * prepped the "oid" field with the current value of + * the ref, which is the most reasonable fallback. + * + * We'll put dummy values into the out-parameters (so + * they're not just uninitialized garbage), and the + * caller can take our return value as a hint that + * we did not find any such reflog. + */ + set_read_ref_cutoffs(&cb, 0, 0, "empty reflog"); + return 1; + } + if (flags & GET_OID_QUIETLY) + exit(128); + else + die(_("log for %s is empty"), refname); + } + if (cb.found_it) + return 0; + + refs_for_each_reflog_ent(refs, refname, read_ref_at_ent_oldest, &cb); + + return 1; +} + +struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs, + unsigned int flags, + struct strbuf *err) +{ + struct ref_transaction *tr; + assert(err); + + CALLOC_ARRAY(tr, 1); + tr->ref_store = refs; + tr->flags = flags; + string_list_init_dup(&tr->refnames); + + if (flags & REF_TRANSACTION_ALLOW_FAILURE) + CALLOC_ARRAY(tr->rejections, 1); + + return tr; +} + +void ref_transaction_free(struct ref_transaction *transaction) +{ + size_t i; + + if (!transaction) + return; + + switch (transaction->state) { + case REF_TRANSACTION_OPEN: + case REF_TRANSACTION_CLOSED: + /* OK */ + break; + case REF_TRANSACTION_PREPARED: + BUG("free called on a prepared reference transaction"); + break; + default: + BUG("unexpected reference transaction state"); + break; + } + + for (i = 0; i < transaction->nr; i++) { + free(transaction->updates[i]->msg); + free(transaction->updates[i]->committer_info); + free((char *)transaction->updates[i]->new_target); + free((char *)transaction->updates[i]->old_target); + free(transaction->updates[i]); + } + + if (transaction->rejections) + free(transaction->rejections->update_indices); + free(transaction->rejections); + + string_list_clear(&transaction->refnames, 0); + free(transaction->updates); + free(transaction); +} + +int ref_transaction_maybe_set_rejected(struct ref_transaction *transaction, + size_t update_idx, + enum ref_transaction_error err) +{ + if (update_idx >= transaction->nr) + BUG("trying to set rejection on invalid update index"); + + if (!(transaction->flags & REF_TRANSACTION_ALLOW_FAILURE)) + return 0; + + if (!transaction->rejections) + BUG("transaction not inititalized with failure support"); + + /* + * Don't accept generic errors, since these errors are not user + * input related. + */ + if (err == REF_TRANSACTION_ERROR_GENERIC) + return 0; + + transaction->updates[update_idx]->rejection_err = err; + ALLOC_GROW(transaction->rejections->update_indices, + transaction->rejections->nr + 1, + transaction->rejections->alloc); + transaction->rejections->update_indices[transaction->rejections->nr++] = update_idx; + + return 1; +} + +struct ref_update *ref_transaction_add_update( + struct ref_transaction *transaction, + const char *refname, unsigned int flags, + const struct object_id *new_oid, + const struct object_id *old_oid, + const char *new_target, const char *old_target, + const char *committer_info, + const char *msg) +{ + struct string_list_item *item; + struct ref_update *update; + + if (transaction->state != REF_TRANSACTION_OPEN) + BUG("update called for transaction that is not open"); + + if (old_oid && old_target) + BUG("only one of old_oid and old_target should be non NULL"); + if (new_oid && new_target) + BUG("only one of new_oid and new_target should be non NULL"); + + FLEX_ALLOC_STR(update, refname, refname); + ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc); + transaction->updates[transaction->nr++] = update; + + update->flags = flags; + update->rejection_err = 0; + + update->new_target = xstrdup_or_null(new_target); + update->old_target = xstrdup_or_null(old_target); + if ((flags & REF_HAVE_NEW) && new_oid) + oidcpy(&update->new_oid, new_oid); + if ((flags & REF_HAVE_OLD) && old_oid) + oidcpy(&update->old_oid, old_oid); + if (!(flags & REF_SKIP_CREATE_REFLOG)) { + update->committer_info = xstrdup_or_null(committer_info); + update->msg = normalize_reflog_message(msg); + } + + /* + * This list is generally used by the backends to avoid duplicates. + * But we do support multiple log updates for a given refname within + * a single transaction. + */ + if (!(update->flags & REF_LOG_ONLY)) { + item = string_list_append(&transaction->refnames, refname); + item->util = update; + } + + return update; +} + +static int transaction_refname_valid(const char *refname, + const struct object_id *new_oid, + unsigned int flags, struct strbuf *err) +{ + if (flags & REF_SKIP_REFNAME_VERIFICATION) + return 1; + + if (is_pseudo_ref(refname)) { + const char *refusal_msg; + if (flags & REF_LOG_ONLY) + refusal_msg = _("refusing to update reflog for pseudoref '%s'"); + else + refusal_msg = _("refusing to update pseudoref '%s'"); + strbuf_addf(err, refusal_msg, refname); + return 0; + } else if ((new_oid && !is_null_oid(new_oid)) ? + check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) : + !refname_is_safe(refname)) { + const char *refusal_msg; + if (flags & REF_LOG_ONLY) + refusal_msg = _("refusing to update reflog with bad name '%s'"); + else + refusal_msg = _("refusing to update ref with bad name '%s'"); + strbuf_addf(err, refusal_msg, refname); + return 0; + } + + return 1; +} + +int ref_transaction_update(struct ref_transaction *transaction, + const char *refname, + const struct object_id *new_oid, + const struct object_id *old_oid, + const char *new_target, + const char *old_target, + unsigned int flags, const char *msg, + struct strbuf *err) +{ + assert(err); + + if ((flags & REF_FORCE_CREATE_REFLOG) && + (flags & REF_SKIP_CREATE_REFLOG)) { + strbuf_addstr(err, _("refusing to force and skip creation of reflog")); + return -1; + } + + if (!transaction_refname_valid(refname, new_oid, flags, err)) + return -1; + + if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS) + BUG("illegal flags 0x%x passed to ref_transaction_update()", flags); + + /* + * Clear flags outside the allowed set; this should be a noop because + * of the BUG() check above, but it works around a -Wnonnull warning + * with some versions of "gcc -O3". + */ + flags &= REF_TRANSACTION_UPDATE_ALLOWED_FLAGS; + + flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0); + flags |= (new_target ? REF_HAVE_NEW : 0) | (old_target ? REF_HAVE_OLD : 0); + + ref_transaction_add_update(transaction, refname, flags, + new_oid, old_oid, new_target, + old_target, NULL, msg); + + return 0; +} + +/* + * Similar to`ref_transaction_update`, but this function is only for adding + * a reflog update. Supports providing custom committer information. The index + * field can be utiltized to order updates as desired. When not used, the + * updates default to being ordered by refname. + */ +static int ref_transaction_update_reflog(struct ref_transaction *transaction, + const char *refname, + const struct object_id *new_oid, + const struct object_id *old_oid, + const char *committer_info, + unsigned int flags, + const char *msg, + uint64_t index, + struct strbuf *err) +{ + struct ref_update *update; + + assert(err); + + flags |= REF_LOG_ONLY | REF_FORCE_CREATE_REFLOG | REF_NO_DEREF; + + if (!transaction_refname_valid(refname, new_oid, flags, err)) + return -1; + + update = ref_transaction_add_update(transaction, refname, flags, + new_oid, old_oid, NULL, NULL, + committer_info, msg); + /* + * While we do set the old_oid value, we unset the flag to skip + * old_oid verification which only makes sense for refs. + */ + update->flags &= ~REF_HAVE_OLD; + update->index = index; + + /* + * Reference backends may need to know the max index to optimize + * their writes. So we store the max_index on the transaction level. + */ + if (index > transaction->max_index) + transaction->max_index = index; + + return 0; +} + +int ref_transaction_create(struct ref_transaction *transaction, + const char *refname, + const struct object_id *new_oid, + const char *new_target, + unsigned int flags, const char *msg, + struct strbuf *err) +{ + if (new_oid && new_target) + BUG("create called with both new_oid and new_target set"); + if ((!new_oid || is_null_oid(new_oid)) && !new_target) { + strbuf_addf(err, "'%s' has neither a valid OID nor a target", refname); + return 1; + } + return ref_transaction_update(transaction, refname, new_oid, + null_oid(the_hash_algo), new_target, NULL, flags, + msg, err); +} + +int ref_transaction_delete(struct ref_transaction *transaction, + const char *refname, + const struct object_id *old_oid, + const char *old_target, + unsigned int flags, + const char *msg, + struct strbuf *err) +{ + if (old_oid && is_null_oid(old_oid)) + BUG("delete called with old_oid set to zeros"); + if (old_oid && old_target) + BUG("delete called with both old_oid and old_target set"); + if (old_target && !(flags & REF_NO_DEREF)) + BUG("delete cannot operate on symrefs with deref mode"); + return ref_transaction_update(transaction, refname, + null_oid(the_hash_algo), old_oid, + NULL, old_target, flags, + msg, err); +} + +int ref_transaction_verify(struct ref_transaction *transaction, + const char *refname, + const struct object_id *old_oid, + const char *old_target, + unsigned int flags, + struct strbuf *err) +{ + if (!old_target && !old_oid) + BUG("verify called with old_oid and old_target set to NULL"); + if (old_oid && old_target) + BUG("verify called with both old_oid and old_target set"); + if (old_target && !(flags & REF_NO_DEREF)) + BUG("verify cannot operate on symrefs with deref mode"); + return ref_transaction_update(transaction, refname, + NULL, old_oid, + NULL, old_target, + flags, NULL, err); +} + +int refs_update_ref(struct ref_store *refs, const char *msg, + const char *refname, const struct object_id *new_oid, + const struct object_id *old_oid, unsigned int flags, + enum action_on_err onerr) +{ + struct ref_transaction *t = NULL; + struct strbuf err = STRBUF_INIT; + int ret = 0; + + t = ref_store_transaction_begin(refs, 0, &err); + if (!t || + ref_transaction_update(t, refname, new_oid, old_oid, NULL, NULL, + flags, msg, &err) || + ref_transaction_commit(t, &err)) { + ret = 1; + ref_transaction_free(t); + } + if (ret) { + const char *str = _("update_ref failed for ref '%s': %s"); + + switch (onerr) { + case UPDATE_REFS_MSG_ON_ERR: + error(str, refname, err.buf); + break; + case UPDATE_REFS_DIE_ON_ERR: + die(str, refname, err.buf); + break; + case UPDATE_REFS_QUIET_ON_ERR: + break; + } + strbuf_release(&err); + return 1; + } + strbuf_release(&err); + if (t) + ref_transaction_free(t); + return 0; +} + +/* + * Check that the string refname matches a rule of the form + * "{prefix}%.*s{suffix}". So "foo/bar/baz" would match the rule + * "foo/%.*s/baz", and return the string "bar". + */ +static const char *match_parse_rule(const char *refname, const char *rule, + size_t *len) +{ + /* + * Check that rule matches refname up to the first percent in the rule. + * We can bail immediately if not, but otherwise we leave "rule" at the + * %-placeholder, and "refname" at the start of the potential matched + * name. + */ + while (*rule != '%') { + if (!*rule) + BUG("rev-parse rule did not have percent"); + if (*refname++ != *rule++) + return NULL; + } + + /* + * Check that our "%" is the expected placeholder. This assumes there + * are no other percents (placeholder or quoted) in the string, but + * that is sufficient for our rev-parse rules. + */ + if (!skip_prefix(rule, "%.*s", &rule)) + return NULL; + + /* + * And now check that our suffix (if any) matches. + */ + if (!strip_suffix(refname, rule, len)) + return NULL; + + return refname; /* len set by strip_suffix() */ +} + +char *refs_shorten_unambiguous_ref(struct ref_store *refs, + const char *refname, int strict) +{ + int i; + struct strbuf resolved_buf = STRBUF_INIT; + + /* skip first rule, it will always match */ + for (i = NUM_REV_PARSE_RULES - 1; i > 0 ; --i) { + int j; + int rules_to_fail = i; + const char *short_name; + size_t short_name_len; + + short_name = match_parse_rule(refname, ref_rev_parse_rules[i], + &short_name_len); + if (!short_name) + continue; + + /* + * in strict mode, all (except the matched one) rules + * must fail to resolve to a valid non-ambiguous ref + */ + if (strict) + rules_to_fail = NUM_REV_PARSE_RULES; + + /* + * check if the short name resolves to a valid ref, + * but use only rules prior to the matched one + */ + for (j = 0; j < rules_to_fail; j++) { + const char *rule = ref_rev_parse_rules[j]; + + /* skip matched rule */ + if (i == j) + continue; + + /* + * the short name is ambiguous, if it resolves + * (with this previous rule) to a valid ref + * read_ref() returns 0 on success + */ + strbuf_reset(&resolved_buf); + strbuf_addf(&resolved_buf, rule, + cast_size_t_to_int(short_name_len), + short_name); + if (refs_ref_exists(refs, resolved_buf.buf)) + break; + } + + /* + * short name is non-ambiguous if all previous rules + * haven't resolved to a valid ref + */ + if (j == rules_to_fail) { + strbuf_release(&resolved_buf); + return xmemdupz(short_name, short_name_len); + } + } + + strbuf_release(&resolved_buf); + return xstrdup(refname); +} + +int parse_hide_refs_config(const char *var, const char *value, const char *section, + struct strvec *hide_refs) +{ + const char *key; + if (!strcmp("transfer.hiderefs", var) || + (!parse_config_key(var, section, NULL, NULL, &key) && + !strcmp(key, "hiderefs"))) { + char *ref; + int len; + + if (!value) + return config_error_nonbool(var); + + /* drop const to remove trailing '/' characters */ + ref = (char *)strvec_push(hide_refs, value); + len = strlen(ref); + while (len && ref[len - 1] == '/') + ref[--len] = '\0'; + } + return 0; +} + +int ref_is_hidden(const char *refname, const char *refname_full, + const struct strvec *hide_refs) +{ + int i; + + for (i = hide_refs->nr - 1; i >= 0; i--) { + const char *match = hide_refs->v[i]; + const char *subject; + int neg = 0; + const char *p; + + if (*match == '!') { + neg = 1; + match++; + } + + if (*match == '^') { + subject = refname_full; + match++; + } else { + subject = refname; + } + + /* refname can be NULL when namespaces are used. */ + if (subject && + skip_prefix(subject, match, &p) && + (!*p || *p == '/')) + return !neg; + } + return 0; +} + +const char **hidden_refs_to_excludes(const struct strvec *hide_refs) +{ + const char **pattern; + for (pattern = hide_refs->v; *pattern; pattern++) { + /* + * We can't feed any excludes from hidden refs config + * sections, since later rules may override previous + * ones. For example, with rules "refs/foo" and + * "!refs/foo/bar", we should show "refs/foo/bar" (and + * everything underneath it), but the earlier exclusion + * would cause us to skip all of "refs/foo". We + * likewise don't implement the namespace stripping + * required for '^' rules. + * + * Both are possible to do, but complicated, so avoid + * populating the jump list at all if we see either of + * these patterns. + */ + if (**pattern == '!' || **pattern == '^') + return NULL; + } + return hide_refs->v; +} + +const char **get_namespaced_exclude_patterns(const char **exclude_patterns, + const char *namespace, + struct strvec *out) +{ + if (!namespace || !*namespace || !exclude_patterns || !*exclude_patterns) + return exclude_patterns; + + for (size_t i = 0; exclude_patterns[i]; i++) + strvec_pushf(out, "%s%s", namespace, exclude_patterns[i]); + + return out->v; +} + +const char *find_descendant_ref(const char *dirname, + const struct string_list *extras, + const struct string_list *skip) +{ + int pos; + + if (!extras) + return NULL; + + /* + * Look at the place where dirname would be inserted into + * extras. If there is an entry at that position that starts + * with dirname (remember, dirname includes the trailing + * slash) and is not in skip, then we have a conflict. + */ + for (pos = string_list_find_insert_index(extras, dirname, 0); + pos < extras->nr; pos++) { + const char *extra_refname = extras->items[pos].string; + + if (!starts_with(extra_refname, dirname)) + break; + + if (!skip || !string_list_has_string(skip, extra_refname)) + return extra_refname; + } + return NULL; +} + +int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data) +{ + struct object_id oid; + int flag; + + if (refs_resolve_ref_unsafe(refs, "HEAD", RESOLVE_REF_READING, + &oid, &flag)) + return fn("HEAD", NULL, &oid, flag, cb_data); + + return 0; +} + +struct ref_iterator *refs_ref_iterator_begin( + struct ref_store *refs, + const char *prefix, + const char **exclude_patterns, + int trim, + enum do_for_each_ref_flags flags) +{ + struct ref_iterator *iter; + struct strvec normalized_exclude_patterns = STRVEC_INIT; + + if (exclude_patterns) { + for (size_t i = 0; exclude_patterns[i]; i++) { + const char *pattern = exclude_patterns[i]; + size_t len = strlen(pattern); + if (!len) + continue; + + if (pattern[len - 1] == '/') + strvec_push(&normalized_exclude_patterns, pattern); + else + strvec_pushf(&normalized_exclude_patterns, "%s/", + pattern); + } + + exclude_patterns = normalized_exclude_patterns.v; + } + + if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) { + static int ref_paranoia = -1; + + if (ref_paranoia < 0) + ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 1); + if (ref_paranoia) { + flags |= DO_FOR_EACH_INCLUDE_BROKEN; + flags |= DO_FOR_EACH_OMIT_DANGLING_SYMREFS; + } + } + + iter = refs->be->iterator_begin(refs, prefix, exclude_patterns, flags); + /* + * `iterator_begin()` already takes care of prefix, but we + * might need to do some trimming: + */ + if (trim) + iter = prefix_ref_iterator_begin(iter, "", trim); + + strvec_clear(&normalized_exclude_patterns); + + return iter; +} + +static int do_for_each_ref(struct ref_store *refs, const char *prefix, + const char **exclude_patterns, + each_ref_fn fn, int trim, + enum do_for_each_ref_flags flags, void *cb_data) +{ + struct ref_iterator *iter; + + if (!refs) + return 0; + + iter = refs_ref_iterator_begin(refs, prefix, exclude_patterns, trim, + flags); + + return do_for_each_ref_iterator(iter, fn, cb_data); +} + +int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data) +{ + return do_for_each_ref(refs, "", NULL, fn, 0, 0, cb_data); +} + +int refs_for_each_ref_in(struct ref_store *refs, const char *prefix, + each_ref_fn fn, void *cb_data) +{ + return do_for_each_ref(refs, prefix, NULL, fn, strlen(prefix), 0, cb_data); +} + +int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix, + const char **exclude_patterns, + each_ref_fn fn, void *cb_data) +{ + return do_for_each_ref(refs, prefix, exclude_patterns, fn, 0, 0, cb_data); +} + +int refs_for_each_replace_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data) +{ + const char *git_replace_ref_base = ref_namespace[NAMESPACE_REPLACE].ref; + return do_for_each_ref(refs, git_replace_ref_base, NULL, fn, + strlen(git_replace_ref_base), + DO_FOR_EACH_INCLUDE_BROKEN, cb_data); +} + +int refs_for_each_namespaced_ref(struct ref_store *refs, + const char **exclude_patterns, + each_ref_fn fn, void *cb_data) +{ + struct strvec namespaced_exclude_patterns = STRVEC_INIT; + struct strbuf prefix = STRBUF_INIT; + int ret; + + exclude_patterns = get_namespaced_exclude_patterns(exclude_patterns, + get_git_namespace(), + &namespaced_exclude_patterns); + + strbuf_addf(&prefix, "%srefs/", get_git_namespace()); + ret = do_for_each_ref(refs, prefix.buf, exclude_patterns, fn, 0, 0, cb_data); + + strvec_clear(&namespaced_exclude_patterns); + strbuf_release(&prefix); + return ret; +} + +int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data) +{ + return do_for_each_ref(refs, "", NULL, fn, 0, + DO_FOR_EACH_INCLUDE_BROKEN, cb_data); +} + +int refs_for_each_include_root_refs(struct ref_store *refs, each_ref_fn fn, + void *cb_data) +{ + return do_for_each_ref(refs, "", NULL, fn, 0, + DO_FOR_EACH_INCLUDE_ROOT_REFS, cb_data); +} + +static int qsort_strcmp(const void *va, const void *vb) +{ + const char *a = *(const char **)va; + const char *b = *(const char **)vb; + + return strcmp(a, b); +} + +static void find_longest_prefixes_1(struct string_list *out, + struct strbuf *prefix, + const char **patterns, size_t nr) +{ + size_t i; + + for (i = 0; i < nr; i++) { + char c = patterns[i][prefix->len]; + if (!c || is_glob_special(c)) { + string_list_append(out, prefix->buf); + return; + } + } + + i = 0; + while (i < nr) { + size_t end; + + /* + * Set "end" to the index of the element _after_ the last one + * in our group. + */ + for (end = i + 1; end < nr; end++) { + if (patterns[i][prefix->len] != patterns[end][prefix->len]) + break; + } + + strbuf_addch(prefix, patterns[i][prefix->len]); + find_longest_prefixes_1(out, prefix, patterns + i, end - i); + strbuf_setlen(prefix, prefix->len - 1); + + i = end; + } +} + +static void find_longest_prefixes(struct string_list *out, + const char **patterns) +{ + struct strvec sorted = STRVEC_INIT; + struct strbuf prefix = STRBUF_INIT; + + strvec_pushv(&sorted, patterns); + QSORT(sorted.v, sorted.nr, qsort_strcmp); + + find_longest_prefixes_1(out, &prefix, sorted.v, sorted.nr); + + strvec_clear(&sorted); + strbuf_release(&prefix); +} + +int refs_for_each_fullref_in_prefixes(struct ref_store *ref_store, + const char *namespace, + const char **patterns, + const char **exclude_patterns, + each_ref_fn fn, void *cb_data) +{ + struct strvec namespaced_exclude_patterns = STRVEC_INIT; + struct string_list prefixes = STRING_LIST_INIT_DUP; + struct string_list_item *prefix; + struct strbuf buf = STRBUF_INIT; + int ret = 0, namespace_len; + + find_longest_prefixes(&prefixes, patterns); + + if (namespace) + strbuf_addstr(&buf, namespace); + namespace_len = buf.len; + + exclude_patterns = get_namespaced_exclude_patterns(exclude_patterns, + namespace, + &namespaced_exclude_patterns); + + for_each_string_list_item(prefix, &prefixes) { + strbuf_addstr(&buf, prefix->string); + ret = refs_for_each_fullref_in(ref_store, buf.buf, + exclude_patterns, fn, cb_data); + if (ret) + break; + strbuf_setlen(&buf, namespace_len); + } + + strvec_clear(&namespaced_exclude_patterns); + string_list_clear(&prefixes, 0); + strbuf_release(&buf); + return ret; +} + +static int refs_read_special_head(struct ref_store *ref_store, + const char *refname, struct object_id *oid, + struct strbuf *referent, unsigned int *type, + int *failure_errno) +{ + struct strbuf full_path = STRBUF_INIT; + struct strbuf content = STRBUF_INIT; + int result = -1; + strbuf_addf(&full_path, "%s/%s", ref_store->gitdir, refname); + + if (strbuf_read_file(&content, full_path.buf, 0) < 0) { + *failure_errno = errno; + goto done; + } + + result = parse_loose_ref_contents(ref_store->repo->hash_algo, content.buf, + oid, referent, type, NULL, failure_errno); + +done: + strbuf_release(&full_path); + strbuf_release(&content); + return result; +} + +int refs_read_raw_ref(struct ref_store *ref_store, const char *refname, + struct object_id *oid, struct strbuf *referent, + unsigned int *type, int *failure_errno) +{ + assert(failure_errno); + if (is_pseudo_ref(refname)) + return refs_read_special_head(ref_store, refname, oid, referent, + type, failure_errno); + + return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, + type, failure_errno); +} + +int refs_read_symbolic_ref(struct ref_store *ref_store, const char *refname, + struct strbuf *referent) +{ + return ref_store->be->read_symbolic_ref(ref_store, refname, referent); +} + +const char *refs_resolve_ref_unsafe(struct ref_store *refs, + const char *refname, + int resolve_flags, + struct object_id *oid, + int *flags) +{ + static struct strbuf sb_refname = STRBUF_INIT; + struct object_id unused_oid; + int unused_flags; + int symref_count; + + if (!oid) + oid = &unused_oid; + if (!flags) + flags = &unused_flags; + + *flags = 0; + + if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { + if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) || + !refname_is_safe(refname)) + return NULL; + + /* + * repo_dwim_ref() uses REF_ISBROKEN to distinguish between + * missing refs and refs that were present but invalid, + * to complain about the latter to stderr. + * + * We don't know whether the ref exists, so don't set + * REF_ISBROKEN yet. + */ + *flags |= REF_BAD_NAME; + } + + for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) { + unsigned int read_flags = 0; + int failure_errno; + + if (refs_read_raw_ref(refs, refname, oid, &sb_refname, + &read_flags, &failure_errno)) { + *flags |= read_flags; + + /* In reading mode, refs must eventually resolve */ + if (resolve_flags & RESOLVE_REF_READING) + return NULL; + + /* + * Otherwise a missing ref is OK. But the files backend + * may show errors besides ENOENT if there are + * similarly-named refs. + */ + if (failure_errno != ENOENT && + failure_errno != EISDIR && + failure_errno != ENOTDIR) + return NULL; + + oidclr(oid, refs->repo->hash_algo); + if (*flags & REF_BAD_NAME) + *flags |= REF_ISBROKEN; + return refname; + } + + *flags |= read_flags; + + if (!(read_flags & REF_ISSYMREF)) { + if (*flags & REF_BAD_NAME) { + oidclr(oid, refs->repo->hash_algo); + *flags |= REF_ISBROKEN; + } + return refname; + } + + refname = sb_refname.buf; + if (resolve_flags & RESOLVE_REF_NO_RECURSE) { + oidclr(oid, refs->repo->hash_algo); + return refname; + } + if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { + if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) || + !refname_is_safe(refname)) + return NULL; + + *flags |= REF_ISBROKEN | REF_BAD_NAME; + } + } + + return NULL; +} + +/* backend functions */ +int ref_store_create_on_disk(struct ref_store *refs, int flags, struct strbuf *err) +{ + return refs->be->create_on_disk(refs, flags, err); +} + +int ref_store_remove_on_disk(struct ref_store *refs, struct strbuf *err) +{ + return refs->be->remove_on_disk(refs, err); +} + +int repo_resolve_gitlink_ref(struct repository *r, + const char *submodule, const char *refname, + struct object_id *oid) +{ + struct ref_store *refs; + int flags; + + refs = repo_get_submodule_ref_store(r, submodule); + if (!refs) + return -1; + + if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) || + is_null_oid(oid)) + return -1; + return 0; +} + +/* + * Look up a ref store by name. If that ref_store hasn't been + * registered yet, return NULL. + */ +static struct ref_store *lookup_ref_store_map(struct strmap *map, + const char *name) +{ + struct strmap_entry *entry; + + if (!map->map.tablesize) + /* It's initialized on demand in register_ref_store(). */ + return NULL; + + entry = strmap_get_entry(map, name); + return entry ? entry->value : NULL; +} + +/* + * Create, record, and return a ref_store instance for the specified + * gitdir using the given ref storage format. + */ +static struct ref_store *ref_store_init(struct repository *repo, + enum ref_storage_format format, + const char *gitdir, + unsigned int flags) +{ + const struct ref_storage_be *be; + struct ref_store *refs; + + be = find_ref_storage_backend(format); + if (!be) + BUG("reference backend is unknown"); + + refs = be->init(repo, gitdir, flags); + return refs; +} + +void ref_store_release(struct ref_store *ref_store) +{ + ref_store->be->release(ref_store); + free(ref_store->gitdir); +} + +struct ref_store *get_main_ref_store(struct repository *r) +{ + if (r->refs_private) + return r->refs_private; + + if (!r->gitdir) + BUG("attempting to get main_ref_store outside of repository"); + + r->refs_private = ref_store_init(r, r->ref_storage_format, + r->gitdir, REF_STORE_ALL_CAPS); + r->refs_private = maybe_debug_wrap_ref_store(r->gitdir, r->refs_private); + return r->refs_private; +} + +/* + * Associate a ref store with a name. It is a fatal error to call this + * function twice for the same name. + */ +static void register_ref_store_map(struct strmap *map, + const char *type, + struct ref_store *refs, + const char *name) +{ + if (!map->map.tablesize) + strmap_init(map); + if (strmap_put(map, name, refs)) + BUG("%s ref_store '%s' initialized twice", type, name); +} + +struct ref_store *repo_get_submodule_ref_store(struct repository *repo, + const char *submodule) +{ + struct strbuf submodule_sb = STRBUF_INIT; + struct ref_store *refs; + char *to_free = NULL; + size_t len; + struct repository *subrepo; + + if (!submodule) + return NULL; + + len = strlen(submodule); + while (len && is_dir_sep(submodule[len - 1])) + len--; + if (!len) + return NULL; + + if (submodule[len]) + /* We need to strip off one or more trailing slashes */ + submodule = to_free = xmemdupz(submodule, len); + + refs = lookup_ref_store_map(&repo->submodule_ref_stores, submodule); + if (refs) + goto done; + + strbuf_addstr(&submodule_sb, submodule); + if (!is_nonbare_repository_dir(&submodule_sb)) + goto done; + + if (submodule_to_gitdir(repo, &submodule_sb, submodule)) + goto done; + + subrepo = xmalloc(sizeof(*subrepo)); + + if (repo_submodule_init(subrepo, repo, submodule, + null_oid(the_hash_algo))) { + free(subrepo); + goto done; + } + refs = ref_store_init(subrepo, subrepo->ref_storage_format, + submodule_sb.buf, + REF_STORE_READ | REF_STORE_ODB); + register_ref_store_map(&repo->submodule_ref_stores, "submodule", + refs, submodule); + +done: + strbuf_release(&submodule_sb); + free(to_free); + + return refs; +} + +struct ref_store *get_worktree_ref_store(const struct worktree *wt) +{ + struct ref_store *refs; + const char *id; + + if (wt->is_current) + return get_main_ref_store(wt->repo); + + id = wt->id ? wt->id : "/"; + refs = lookup_ref_store_map(&wt->repo->worktree_ref_stores, id); + if (refs) + return refs; + + if (wt->id) { + struct strbuf common_path = STRBUF_INIT; + repo_common_path_append(wt->repo, &common_path, + "worktrees/%s", wt->id); + refs = ref_store_init(wt->repo, wt->repo->ref_storage_format, + common_path.buf, REF_STORE_ALL_CAPS); + strbuf_release(&common_path); + } else { + refs = ref_store_init(wt->repo, wt->repo->ref_storage_format, + wt->repo->commondir, REF_STORE_ALL_CAPS); + } + + if (refs) + register_ref_store_map(&wt->repo->worktree_ref_stores, + "worktree", refs, id); + + return refs; +} + +void base_ref_store_init(struct ref_store *refs, struct repository *repo, + const char *path, const struct ref_storage_be *be) +{ + refs->be = be; + refs->repo = repo; + refs->gitdir = xstrdup(path); +} + +/* backend functions */ +int refs_pack_refs(struct ref_store *refs, struct pack_refs_opts *opts) +{ + return refs->be->pack_refs(refs, opts); +} + +int peel_iterated_oid(struct repository *r, const struct object_id *base, struct object_id *peeled) +{ + if (current_ref_iter && + (current_ref_iter->oid == base || + oideq(current_ref_iter->oid, base))) + return ref_iterator_peel(current_ref_iter, peeled); + + return peel_object(r, base, peeled) ? -1 : 0; +} + +int refs_update_symref(struct ref_store *refs, const char *ref, + const char *target, const char *logmsg) +{ + return refs_update_symref_extended(refs, ref, target, logmsg, NULL, 0); +} + +int refs_update_symref_extended(struct ref_store *refs, const char *ref, + const char *target, const char *logmsg, + struct strbuf *referent, int create_only) +{ + struct ref_transaction *transaction; + struct strbuf err = STRBUF_INIT; + int ret = 0, prepret = 0; + + transaction = ref_store_transaction_begin(refs, 0, &err); + if (!transaction) { + error_return: + ret = error("%s", err.buf); + goto cleanup; + } + if (create_only) { + if (ref_transaction_create(transaction, ref, NULL, target, + REF_NO_DEREF, logmsg, &err)) + goto error_return; + prepret = ref_transaction_prepare(transaction, &err); + if (prepret && prepret != REF_TRANSACTION_ERROR_CREATE_EXISTS) + goto error_return; + } else { + if (ref_transaction_update(transaction, ref, NULL, NULL, + target, NULL, REF_NO_DEREF, + logmsg, &err) || + ref_transaction_prepare(transaction, &err)) + goto error_return; + } + + if (referent && refs_read_symbolic_ref(refs, ref, referent) == NOT_A_SYMREF) { + struct object_id oid; + if (!refs_read_ref(refs, ref, &oid)) { + strbuf_addstr(referent, oid_to_hex(&oid)); + ret = NOT_A_SYMREF; + } + } + + if (prepret == REF_TRANSACTION_ERROR_CREATE_EXISTS) + goto cleanup; + + if (ref_transaction_commit(transaction, &err)) + goto error_return; + +cleanup: + strbuf_release(&err); + if (transaction) + ref_transaction_free(transaction); + + return ret; +} + +/* + * Write an error to `err` and return a nonzero value iff the same + * refname appears multiple times in `refnames`. `refnames` must be + * sorted on entry to this function. + */ +static int ref_update_reject_duplicates(struct string_list *refnames, + struct strbuf *err) +{ + size_t i, n = refnames->nr; + + assert(err); + + for (i = 1; i < n; i++) { + int cmp = strcmp(refnames->items[i - 1].string, + refnames->items[i].string); + + if (!cmp) { + strbuf_addf(err, + _("multiple updates for ref '%s' not allowed"), + refnames->items[i].string); + return 1; + } else if (cmp > 0) { + BUG("ref_update_reject_duplicates() received unsorted list"); + } + } + return 0; +} + +static int run_transaction_hook(struct ref_transaction *transaction, + const char *state) +{ + struct child_process proc = CHILD_PROCESS_INIT; + struct strbuf buf = STRBUF_INIT; + const char *hook; + int ret = 0, i; + + hook = find_hook(transaction->ref_store->repo, "reference-transaction"); + if (!hook) + return ret; + + strvec_pushl(&proc.args, hook, state, NULL); + proc.in = -1; + proc.stdout_to_stderr = 1; + proc.trace2_hook_name = "reference-transaction"; + + ret = start_command(&proc); + if (ret) + return ret; + + sigchain_push(SIGPIPE, SIG_IGN); + + for (i = 0; i < transaction->nr; i++) { + struct ref_update *update = transaction->updates[i]; + + if (update->flags & REF_LOG_ONLY) + continue; + + strbuf_reset(&buf); + + if (!(update->flags & REF_HAVE_OLD)) + strbuf_addf(&buf, "%s ", oid_to_hex(null_oid(the_hash_algo))); + else if (update->old_target) + strbuf_addf(&buf, "ref:%s ", update->old_target); + else + strbuf_addf(&buf, "%s ", oid_to_hex(&update->old_oid)); + + if (!(update->flags & REF_HAVE_NEW)) + strbuf_addf(&buf, "%s ", oid_to_hex(null_oid(the_hash_algo))); + else if (update->new_target) + strbuf_addf(&buf, "ref:%s ", update->new_target); + else + strbuf_addf(&buf, "%s ", oid_to_hex(&update->new_oid)); + + strbuf_addf(&buf, "%s\n", update->refname); + + if (write_in_full(proc.in, buf.buf, buf.len) < 0) { + if (errno != EPIPE) { + /* Don't leak errno outside this API */ + errno = 0; + ret = -1; + } + break; + } + } + + close(proc.in); + sigchain_pop(SIGPIPE); + strbuf_release(&buf); + + ret |= finish_command(&proc); + return ret; +} + +int ref_transaction_prepare(struct ref_transaction *transaction, + struct strbuf *err) +{ + struct ref_store *refs = transaction->ref_store; + int ret; + + switch (transaction->state) { + case REF_TRANSACTION_OPEN: + /* Good. */ + break; + case REF_TRANSACTION_PREPARED: + BUG("prepare called twice on reference transaction"); + break; + case REF_TRANSACTION_CLOSED: + BUG("prepare called on a closed reference transaction"); + break; + default: + BUG("unexpected reference transaction state"); + break; + } + + if (refs->repo->objects->sources->disable_ref_updates) { + strbuf_addstr(err, + _("ref updates forbidden inside quarantine environment")); + return -1; + } + + string_list_sort(&transaction->refnames); + if (ref_update_reject_duplicates(&transaction->refnames, err)) + return REF_TRANSACTION_ERROR_GENERIC; + + ret = refs->be->transaction_prepare(refs, transaction, err); + if (ret) + return ret; + + ret = run_transaction_hook(transaction, "prepared"); + if (ret) { + ref_transaction_abort(transaction, err); + die(_("ref updates aborted by hook")); + } + + return 0; +} + +int ref_transaction_abort(struct ref_transaction *transaction, + struct strbuf *err) +{ + struct ref_store *refs = transaction->ref_store; + int ret = 0; + + switch (transaction->state) { + case REF_TRANSACTION_OPEN: + /* No need to abort explicitly. */ + break; + case REF_TRANSACTION_PREPARED: + ret = refs->be->transaction_abort(refs, transaction, err); + break; + case REF_TRANSACTION_CLOSED: + BUG("abort called on a closed reference transaction"); + break; + default: + BUG("unexpected reference transaction state"); + break; + } + + run_transaction_hook(transaction, "aborted"); + + ref_transaction_free(transaction); + return ret; +} + +int ref_transaction_commit(struct ref_transaction *transaction, + struct strbuf *err) +{ + struct ref_store *refs = transaction->ref_store; + int ret; + + switch (transaction->state) { + case REF_TRANSACTION_OPEN: + /* Need to prepare first. */ + ret = ref_transaction_prepare(transaction, err); + if (ret) + return ret; + break; + case REF_TRANSACTION_PREPARED: + /* Fall through to finish. */ + break; + case REF_TRANSACTION_CLOSED: + BUG("commit called on a closed reference transaction"); + break; + default: + BUG("unexpected reference transaction state"); + break; + } + + ret = refs->be->transaction_finish(refs, transaction, err); + if (!ret && !(transaction->flags & REF_TRANSACTION_FLAG_INITIAL)) + run_transaction_hook(transaction, "committed"); + return ret; +} + +enum ref_transaction_error refs_verify_refnames_available(struct ref_store *refs, + const struct string_list *refnames, + const struct string_list *extras, + const struct string_list *skip, + struct ref_transaction *transaction, + unsigned int initial_transaction, + struct strbuf *err) +{ + struct strbuf dirname = STRBUF_INIT; + struct strbuf referent = STRBUF_INIT; + struct string_list_item *item; + struct ref_iterator *iter = NULL; + struct strset conflicting_dirnames; + struct strset dirnames; + int ret = REF_TRANSACTION_ERROR_NAME_CONFLICT; + + /* + * For the sake of comments in this function, suppose that + * refname is "refs/foo/bar". + */ + + assert(err); + + strset_init(&conflicting_dirnames); + strset_init(&dirnames); + + for_each_string_list_item(item, refnames) { + const size_t *update_idx = (size_t *)item->util; + const char *refname = item->string; + const char *extra_refname; + struct object_id oid; + unsigned int type; + const char *slash; + + strbuf_reset(&dirname); + + for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { + /* + * Just saying "Is a directory" when we e.g. can't + * lock some multi-level ref isn't very informative, + * the user won't be told *what* is a directory, so + * let's not use strerror() below. + */ + int ignore_errno; + + /* Expand dirname to the new prefix, not including the trailing slash: */ + strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); + + /* + * We are still at a leading dir of the refname (e.g., + * "refs/foo"; if there is a reference with that name, + * it is a conflict, *unless* it is in skip. + */ + if (skip && string_list_has_string(skip, dirname.buf)) + continue; + + /* + * If we've already seen the directory we don't need to + * process it again. Skip it to avoid checking common + * prefixes like "refs/heads/" repeatedly. + */ + if (!strset_add(&dirnames, dirname.buf)) + continue; + + if (!initial_transaction && + (strset_contains(&conflicting_dirnames, dirname.buf) || + !refs_read_raw_ref(refs, dirname.buf, &oid, &referent, + &type, &ignore_errno))) { + if (transaction && ref_transaction_maybe_set_rejected( + transaction, *update_idx, + REF_TRANSACTION_ERROR_NAME_CONFLICT)) { + strset_remove(&dirnames, dirname.buf); + strset_add(&conflicting_dirnames, dirname.buf); + continue; + } + + strbuf_addf(err, _("'%s' exists; cannot create '%s'"), + dirname.buf, refname); + goto cleanup; + } + + if (extras && string_list_has_string(extras, dirname.buf)) { + if (transaction && ref_transaction_maybe_set_rejected( + transaction, *update_idx, + REF_TRANSACTION_ERROR_NAME_CONFLICT)) { + strset_remove(&dirnames, dirname.buf); + continue; + } + + strbuf_addf(err, _("cannot process '%s' and '%s' at the same time"), + refname, dirname.buf); + goto cleanup; + } + } + + /* + * We are at the leaf of our refname (e.g., "refs/foo/bar"). + * There is no point in searching for a reference with that + * name, because a refname isn't considered to conflict with + * itself. But we still need to check for references whose + * names are in the "refs/foo/bar/" namespace, because they + * *do* conflict. + */ + strbuf_addstr(&dirname, refname + dirname.len); + strbuf_addch(&dirname, '/'); + + if (!initial_transaction) { + int ok; + + if (!iter) + iter = refs_ref_iterator_begin(refs, dirname.buf, NULL, 0, + DO_FOR_EACH_INCLUDE_BROKEN); + else if (ref_iterator_seek(iter, dirname.buf, + REF_ITERATOR_SEEK_SET_PREFIX) < 0) + goto cleanup; + + while ((ok = ref_iterator_advance(iter)) == ITER_OK) { + if (skip && + string_list_has_string(skip, iter->refname)) + continue; + + if (transaction && ref_transaction_maybe_set_rejected( + transaction, *update_idx, + REF_TRANSACTION_ERROR_NAME_CONFLICT)) + continue; + + strbuf_addf(err, _("'%s' exists; cannot create '%s'"), + iter->refname, refname); + goto cleanup; + } + + if (ok != ITER_DONE) + BUG("error while iterating over references"); + } + + extra_refname = find_descendant_ref(dirname.buf, extras, skip); + if (extra_refname) { + if (transaction && ref_transaction_maybe_set_rejected( + transaction, *update_idx, + REF_TRANSACTION_ERROR_NAME_CONFLICT)) + continue; + + strbuf_addf(err, _("cannot process '%s' and '%s' at the same time"), + refname, extra_refname); + goto cleanup; + } + } + + ret = 0; + +cleanup: + strbuf_release(&referent); + strbuf_release(&dirname); + strset_clear(&conflicting_dirnames); + strset_clear(&dirnames); + ref_iterator_free(iter); + return ret; +} + +enum ref_transaction_error refs_verify_refname_available( + struct ref_store *refs, + const char *refname, + const struct string_list *extras, + const struct string_list *skip, + unsigned int initial_transaction, + struct strbuf *err) +{ + struct string_list_item item = { .string = (char *) refname }; + struct string_list refnames = { + .items = &item, + .nr = 1, + }; + + return refs_verify_refnames_available(refs, &refnames, extras, skip, + NULL, initial_transaction, err); +} + +struct do_for_each_reflog_help { + each_reflog_fn *fn; + void *cb_data; +}; + +static int do_for_each_reflog_helper(const char *refname, + const char *referent UNUSED, + const struct object_id *oid UNUSED, + int flags UNUSED, + void *cb_data) +{ + struct do_for_each_reflog_help *hp = cb_data; + return hp->fn(refname, hp->cb_data); +} + +int refs_for_each_reflog(struct ref_store *refs, each_reflog_fn fn, void *cb_data) +{ + struct ref_iterator *iter; + struct do_for_each_reflog_help hp = { fn, cb_data }; + + iter = refs->be->reflog_iterator_begin(refs); + + return do_for_each_ref_iterator(iter, do_for_each_reflog_helper, &hp); +} + +int refs_for_each_reflog_ent_reverse(struct ref_store *refs, + const char *refname, + each_reflog_ent_fn fn, + void *cb_data) +{ + return refs->be->for_each_reflog_ent_reverse(refs, refname, + fn, cb_data); +} + +int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname, + each_reflog_ent_fn fn, void *cb_data) +{ + return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data); +} + +int refs_reflog_exists(struct ref_store *refs, const char *refname) +{ + return refs->be->reflog_exists(refs, refname); +} + +int refs_create_reflog(struct ref_store *refs, const char *refname, + struct strbuf *err) +{ + return refs->be->create_reflog(refs, refname, err); +} + +int refs_delete_reflog(struct ref_store *refs, const char *refname) +{ + return refs->be->delete_reflog(refs, refname); +} + +int refs_reflog_expire(struct ref_store *refs, + const char *refname, + 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) +{ + return refs->be->reflog_expire(refs, refname, flags, + prepare_fn, should_prune_fn, + cleanup_fn, policy_cb_data); +} + +void ref_transaction_for_each_queued_update(struct ref_transaction *transaction, + ref_transaction_for_each_queued_update_fn cb, + void *cb_data) +{ + int i; + + for (i = 0; i < transaction->nr; i++) { + struct ref_update *update = transaction->updates[i]; + + cb(update->refname, + (update->flags & REF_HAVE_OLD) ? &update->old_oid : NULL, + (update->flags & REF_HAVE_NEW) ? &update->new_oid : NULL, + cb_data); + } +} + +void ref_transaction_for_each_rejected_update(struct ref_transaction *transaction, + ref_transaction_for_each_rejected_update_fn cb, + void *cb_data) +{ + if (!transaction->rejections) + return; + + for (size_t i = 0; i < transaction->rejections->nr; i++) { + size_t update_index = transaction->rejections->update_indices[i]; + struct ref_update *update = transaction->updates[update_index]; + + if (!update->rejection_err) + continue; + + cb(update->refname, + (update->flags & REF_HAVE_OLD) ? &update->old_oid : NULL, + (update->flags & REF_HAVE_NEW) ? &update->new_oid : NULL, + update->old_target, update->new_target, + update->rejection_err, cb_data); + } +} + +int refs_delete_refs(struct ref_store *refs, const char *logmsg, + struct string_list *refnames, unsigned int flags) +{ + struct ref_transaction *transaction; + struct strbuf err = STRBUF_INIT; + struct string_list_item *item; + int ret = 0, failures = 0; + char *msg; + + if (!refnames->nr) + return 0; + + msg = normalize_reflog_message(logmsg); + + /* + * Since we don't check the references' old_oids, the + * individual updates can't fail, so we can pack all of the + * updates into a single transaction. + */ + transaction = ref_store_transaction_begin(refs, 0, &err); + if (!transaction) { + ret = error("%s", err.buf); + goto out; + } + + for_each_string_list_item(item, refnames) { + ret = ref_transaction_delete(transaction, item->string, + NULL, NULL, flags, msg, &err); + if (ret) { + warning(_("could not delete reference %s: %s"), + item->string, err.buf); + strbuf_reset(&err); + failures = 1; + } + } + + ret = ref_transaction_commit(transaction, &err); + if (ret) { + if (refnames->nr == 1) + error(_("could not delete reference %s: %s"), + refnames->items[0].string, err.buf); + else + error(_("could not delete references: %s"), err.buf); + } + +out: + if (!ret && failures) + ret = -1; + ref_transaction_free(transaction); + strbuf_release(&err); + free(msg); + return ret; +} + +int refs_rename_ref(struct ref_store *refs, const char *oldref, + const char *newref, const char *logmsg) +{ + char *msg; + int retval; + + msg = normalize_reflog_message(logmsg); + retval = refs->be->rename_ref(refs, oldref, newref, msg); + free(msg); + return retval; +} + +int refs_copy_existing_ref(struct ref_store *refs, const char *oldref, + const char *newref, const char *logmsg) +{ + char *msg; + int retval; + + msg = normalize_reflog_message(logmsg); + retval = refs->be->copy_ref(refs, oldref, newref, msg); + free(msg); + return retval; +} + +const char *ref_update_original_update_refname(struct ref_update *update) +{ + while (update->parent_update) + update = update->parent_update; + + return update->refname; +} + +int ref_update_has_null_new_value(struct ref_update *update) +{ + return !update->new_target && is_null_oid(&update->new_oid); +} + +enum ref_transaction_error ref_update_check_old_target(const char *referent, + struct ref_update *update, + struct strbuf *err) +{ + if (!update->old_target) + BUG("called without old_target set"); + + if (!strcmp(referent, update->old_target)) + return 0; + + if (!strcmp(referent, "")) { + strbuf_addf(err, "verifying symref target: '%s': " + "reference is missing but expected %s", + ref_update_original_update_refname(update), + update->old_target); + return REF_TRANSACTION_ERROR_NONEXISTENT_REF; + } + + strbuf_addf(err, "verifying symref target: '%s': is at %s but expected %s", + ref_update_original_update_refname(update), + referent, update->old_target); + return REF_TRANSACTION_ERROR_INCORRECT_OLD_VALUE; +} + +struct migration_data { + struct ref_store *old_refs; + struct ref_transaction *transaction; + struct strbuf *errbuf; + struct strbuf sb; +}; + +static int migrate_one_ref(const char *refname, const char *referent UNUSED, const struct object_id *oid, + int flags, void *cb_data) +{ + struct migration_data *data = cb_data; + struct strbuf symref_target = STRBUF_INIT; + int ret; + + if (flags & REF_ISSYMREF) { + ret = refs_read_symbolic_ref(data->old_refs, refname, &symref_target); + if (ret < 0) + goto done; + + ret = ref_transaction_update(data->transaction, refname, NULL, null_oid(the_hash_algo), + symref_target.buf, NULL, + REF_SKIP_CREATE_REFLOG | REF_NO_DEREF, NULL, data->errbuf); + if (ret < 0) + goto done; + } else { + ret = ref_transaction_create(data->transaction, refname, oid, NULL, + REF_SKIP_CREATE_REFLOG | REF_SKIP_OID_VERIFICATION, + NULL, data->errbuf); + if (ret < 0) + goto done; + } + +done: + strbuf_release(&symref_target); + return ret; +} + +struct reflog_migration_data { + uint64_t index; + const char *refname; + struct ref_store *old_refs; + struct ref_transaction *transaction; + struct strbuf *errbuf; + struct strbuf *sb; +}; + +static int migrate_one_reflog_entry(struct object_id *old_oid, + struct object_id *new_oid, + const char *committer, + timestamp_t timestamp, int tz, + const char *msg, void *cb_data) +{ + struct reflog_migration_data *data = cb_data; + const char *date; + int ret; + + date = show_date(timestamp, tz, DATE_MODE(NORMAL)); + strbuf_reset(data->sb); + /* committer contains name and email */ + strbuf_addstr(data->sb, fmt_ident("", committer, WANT_BLANK_IDENT, date, 0)); + + ret = ref_transaction_update_reflog(data->transaction, data->refname, + new_oid, old_oid, data->sb->buf, + REF_HAVE_NEW | REF_HAVE_OLD, msg, + data->index++, data->errbuf); + return ret; +} + +static int migrate_one_reflog(const char *refname, void *cb_data) +{ + struct migration_data *migration_data = cb_data; + struct reflog_migration_data data = { + .refname = refname, + .old_refs = migration_data->old_refs, + .transaction = migration_data->transaction, + .errbuf = migration_data->errbuf, + .sb = &migration_data->sb, + }; + + return refs_for_each_reflog_ent(migration_data->old_refs, refname, + migrate_one_reflog_entry, &data); +} + +static int move_files(const char *from_path, const char *to_path, struct strbuf *errbuf) +{ + struct strbuf from_buf = STRBUF_INIT, to_buf = STRBUF_INIT; + size_t from_len, to_len; + DIR *from_dir; + int ret; + + from_dir = opendir(from_path); + if (!from_dir) { + strbuf_addf(errbuf, "could not open source directory '%s': %s", + from_path, strerror(errno)); + ret = -1; + goto done; + } + + strbuf_addstr(&from_buf, from_path); + strbuf_complete(&from_buf, '/'); + from_len = from_buf.len; + + strbuf_addstr(&to_buf, to_path); + strbuf_complete(&to_buf, '/'); + to_len = to_buf.len; + + while (1) { + struct dirent *ent; + + errno = 0; + ent = readdir(from_dir); + if (!ent) + break; + + if (!strcmp(ent->d_name, ".") || + !strcmp(ent->d_name, "..")) + continue; + + strbuf_setlen(&from_buf, from_len); + strbuf_addstr(&from_buf, ent->d_name); + + strbuf_setlen(&to_buf, to_len); + strbuf_addstr(&to_buf, ent->d_name); + + ret = rename(from_buf.buf, to_buf.buf); + if (ret < 0) { + strbuf_addf(errbuf, "could not link file '%s' to '%s': %s", + from_buf.buf, to_buf.buf, strerror(errno)); + goto done; + } + } + + if (errno) { + strbuf_addf(errbuf, "could not read entry from directory '%s': %s", + from_path, strerror(errno)); + ret = -1; + goto done; + } + + ret = 0; + +done: + strbuf_release(&from_buf); + strbuf_release(&to_buf); + if (from_dir) + closedir(from_dir); + return ret; +} + +static int has_worktrees(void) +{ + struct worktree **worktrees = get_worktrees(); + int ret = 0; + size_t i; + + for (i = 0; worktrees[i]; i++) { + if (is_main_worktree(worktrees[i])) + continue; + ret = 1; + } + + free_worktrees(worktrees); + return ret; +} + +int repo_migrate_ref_storage_format(struct repository *repo, + enum ref_storage_format format, + unsigned int flags, + struct strbuf *errbuf) +{ + struct ref_store *old_refs = NULL, *new_refs = NULL; + struct ref_transaction *transaction = NULL; + struct strbuf new_gitdir = STRBUF_INIT; + struct migration_data data = { + .sb = STRBUF_INIT, + }; + int did_migrate_refs = 0; + int ret; + + if (repo->ref_storage_format == format) { + strbuf_addstr(errbuf, "current and new ref storage format are equal"); + ret = -1; + goto done; + } + + old_refs = get_main_ref_store(repo); + + /* + * Worktrees complicate the migration because every worktree has a + * separate ref storage. While it should be feasible to implement, this + * is pushed out to a future iteration. + * + * TODO: we should really be passing the caller-provided repository to + * `has_worktrees()`, but our worktree subsystem doesn't yet support + * that. + */ + if (has_worktrees()) { + strbuf_addstr(errbuf, "migrating repositories with worktrees is not supported yet"); + ret = -1; + goto done; + } + + /* + * The overall logic looks like this: + * + * 1. Set up a new temporary directory and initialize it with the new + * format. This is where all refs will be migrated into. + * + * 2. Enumerate all refs and write them into the new ref storage. + * This operation is safe as we do not yet modify the main + * repository. + * + * 3. Enumerate all reflogs and write them into the new ref storage. + * This operation is safe as we do not yet modify the main + * repository. + * + * 4. If we're in dry-run mode then we are done and can hand over the + * directory to the caller for inspection. If not, we now start + * with the destructive part. + * + * 5. Delete the old ref storage from disk. As we have a copy of refs + * in the new ref storage it's okay(ish) if we now get interrupted + * as there is an equivalent copy of all refs available. + * + * 6. Move the new ref storage files into place. + * + * 7. Change the repository format to the new ref format. + */ + strbuf_addf(&new_gitdir, "%s/%s", old_refs->gitdir, "ref_migration.XXXXXX"); + if (!mkdtemp(new_gitdir.buf)) { + strbuf_addf(errbuf, "cannot create migration directory: %s", + strerror(errno)); + ret = -1; + goto done; + } + + new_refs = ref_store_init(repo, format, new_gitdir.buf, + REF_STORE_ALL_CAPS); + ret = ref_store_create_on_disk(new_refs, 0, errbuf); + if (ret < 0) + goto done; + + transaction = ref_store_transaction_begin(new_refs, REF_TRANSACTION_FLAG_INITIAL, + errbuf); + if (!transaction) + goto done; + + data.old_refs = old_refs; + data.transaction = transaction; + data.errbuf = errbuf; + + /* + * We need to use the internal `do_for_each_ref()` here so that we can + * also include broken refs and symrefs. These would otherwise be + * skipped silently. + * + * Ideally, we would do this call while locking the old ref storage + * such that there cannot be any concurrent modifications. We do not + * have the infra for that though, and the "files" backend does not + * allow for a central lock due to its design. It's thus on the user to + * ensure that there are no concurrent writes. + */ + ret = do_for_each_ref(old_refs, "", NULL, migrate_one_ref, 0, + DO_FOR_EACH_INCLUDE_ROOT_REFS | DO_FOR_EACH_INCLUDE_BROKEN, + &data); + if (ret < 0) + goto done; + + if (!(flags & REPO_MIGRATE_REF_STORAGE_FORMAT_SKIP_REFLOG)) { + ret = refs_for_each_reflog(old_refs, migrate_one_reflog, &data); + if (ret < 0) + goto done; + } + + ret = ref_transaction_commit(transaction, errbuf); + if (ret < 0) + goto done; + did_migrate_refs = 1; + + if (flags & REPO_MIGRATE_REF_STORAGE_FORMAT_DRYRUN) { + printf(_("Finished dry-run migration of refs, " + "the result can be found at '%s'\n"), new_gitdir.buf); + ret = 0; + goto done; + } + + /* + * Release the new ref store such that any potentially-open files will + * be closed. This is required for platforms like Cygwin, where + * renaming an open file results in EPERM. + */ + ref_store_release(new_refs); + FREE_AND_NULL(new_refs); + + /* + * Until now we were in the non-destructive phase, where we only + * populated the new ref store. From hereon though we are about + * to get hands by deleting the old ref store and then moving + * the new one into place. + * + * Assuming that there were no concurrent writes, the new ref + * store should have all information. So if we fail from hereon + * we may be in an in-between state, but it would still be able + * to recover by manually moving remaining files from the + * temporary migration directory into place. + */ + ret = ref_store_remove_on_disk(old_refs, errbuf); + if (ret < 0) + goto done; + + ret = move_files(new_gitdir.buf, old_refs->gitdir, errbuf); + if (ret < 0) + goto done; + + if (rmdir(new_gitdir.buf) < 0) + warning_errno(_("could not remove temporary migration directory '%s'"), + new_gitdir.buf); + + /* + * We have migrated the repository, so we now need to adjust the + * repository format so that clients will use the new ref store. + * We also need to swap out the repository's main ref store. + */ + initialize_repository_version(hash_algo_by_ptr(repo->hash_algo), format, 1); + + /* + * Unset the old ref store and release it. `get_main_ref_store()` will + * make sure to lazily re-initialize the repository's ref store with + * the new format. + */ + ref_store_release(old_refs); + FREE_AND_NULL(old_refs); + repo->refs_private = NULL; + + ret = 0; + +done: + if (ret && did_migrate_refs) { + strbuf_complete(errbuf, '\n'); + strbuf_addf(errbuf, _("migrated refs can be found at '%s'"), + new_gitdir.buf); + } + + if (new_refs) { + ref_store_release(new_refs); + free(new_refs); + } + ref_transaction_free(transaction); + strbuf_release(&new_gitdir); + strbuf_release(&data.sb); + return ret; +} + +int ref_update_expects_existing_old_ref(struct ref_update *update) +{ + return (update->flags & REF_HAVE_OLD) && + (!is_null_oid(&update->old_oid) || update->old_target); +} + +const char *ref_transaction_error_msg(enum ref_transaction_error err) +{ + switch (err) { + case REF_TRANSACTION_ERROR_NAME_CONFLICT: + return "refname conflict"; + case REF_TRANSACTION_ERROR_CREATE_EXISTS: + return "reference already exists"; + case REF_TRANSACTION_ERROR_NONEXISTENT_REF: + return "reference does not exist"; + case REF_TRANSACTION_ERROR_INCORRECT_OLD_VALUE: + return "incorrect old value provided"; + case REF_TRANSACTION_ERROR_INVALID_NEW_VALUE: + return "invalid new value provided"; + case REF_TRANSACTION_ERROR_EXPECTED_SYMREF: + return "expected symref but found regular ref"; + default: + return "unknown failure"; + } +} |