diff options
Diffstat (limited to 'src/attrcache.c')
| -rw-r--r-- | src/attrcache.c | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/src/attrcache.c b/src/attrcache.c new file mode 100644 index 000000000..b4579bfc0 --- /dev/null +++ b/src/attrcache.c @@ -0,0 +1,449 @@ +#include "common.h" +#include "repository.h" +#include "attr_file.h" +#include "config.h" +#include "sysdir.h" +#include "ignore.h" + +GIT__USE_STRMAP; + +GIT_INLINE(int) attr_cache_lock(git_attr_cache *cache) +{ + GIT_UNUSED(cache); /* avoid warning if threading is off */ + + if (git_mutex_lock(&cache->lock) < 0) { + giterr_set(GITERR_OS, "Unable to get attr cache lock"); + return -1; + } + return 0; +} + +GIT_INLINE(void) attr_cache_unlock(git_attr_cache *cache) +{ + GIT_UNUSED(cache); /* avoid warning if threading is off */ + git_mutex_unlock(&cache->lock); +} + +GIT_INLINE(git_attr_file_entry *) attr_cache_lookup_entry( + git_attr_cache *cache, const char *path) +{ + khiter_t pos = git_strmap_lookup_index(cache->files, path); + + if (git_strmap_valid_index(cache->files, pos)) + return git_strmap_value_at(cache->files, pos); + else + return NULL; +} + +int git_attr_cache__alloc_file_entry( + git_attr_file_entry **out, + const char *base, + const char *path, + git_pool *pool) +{ + size_t baselen = 0, pathlen = strlen(path); + size_t cachesize = sizeof(git_attr_file_entry) + pathlen + 1; + git_attr_file_entry *ce; + + if (base != NULL && git_path_root(path) < 0) { + baselen = strlen(base); + cachesize += baselen; + + if (baselen && base[baselen - 1] != '/') + cachesize++; + } + + ce = git_pool_mallocz(pool, (uint32_t)cachesize); + GITERR_CHECK_ALLOC(ce); + + if (baselen) { + memcpy(ce->fullpath, base, baselen); + + if (base[baselen - 1] != '/') + ce->fullpath[baselen++] = '/'; + } + memcpy(&ce->fullpath[baselen], path, pathlen); + + ce->path = &ce->fullpath[baselen]; + *out = ce; + + return 0; +} + +/* call with attrcache locked */ +static int attr_cache_make_entry( + git_attr_file_entry **out, git_repository *repo, const char *path) +{ + int error = 0; + git_attr_cache *cache = git_repository_attr_cache(repo); + git_attr_file_entry *entry = NULL; + + error = git_attr_cache__alloc_file_entry( + &entry, git_repository_workdir(repo), path, &cache->pool); + + if (!error) { + git_strmap_insert(cache->files, entry->path, entry, error); + if (error > 0) + error = 0; + } + + *out = entry; + return error; +} + +/* insert entry or replace existing if we raced with another thread */ +static int attr_cache_upsert(git_attr_cache *cache, git_attr_file *file) +{ + git_attr_file_entry *entry; + git_attr_file *old; + + if (attr_cache_lock(cache) < 0) + return -1; + + entry = attr_cache_lookup_entry(cache, file->entry->path); + + GIT_REFCOUNT_OWN(file, entry); + GIT_REFCOUNT_INC(file); + + old = git__compare_and_swap( + &entry->file[file->source], entry->file[file->source], file); + + if (old) { + GIT_REFCOUNT_OWN(old, NULL); + git_attr_file__free(old); + } + + attr_cache_unlock(cache); + return 0; +} + +static int attr_cache_remove(git_attr_cache *cache, git_attr_file *file) +{ + int error = 0; + git_attr_file_entry *entry; + + if (!file) + return 0; + if ((error = attr_cache_lock(cache)) < 0) + return error; + + if ((entry = attr_cache_lookup_entry(cache, file->entry->path)) != NULL) + file = git__compare_and_swap(&entry->file[file->source], file, NULL); + + attr_cache_unlock(cache); + + if (file) { + GIT_REFCOUNT_OWN(file, NULL); + git_attr_file__free(file); + } + + return error; +} + +/* Look up cache entry and file. + * - If entry is not present, create it while the cache is locked. + * - If file is present, increment refcount before returning it, so the + * cache can be unlocked and it won't go away. + */ +static int attr_cache_lookup( + git_attr_file **out_file, + git_attr_file_entry **out_entry, + git_repository *repo, + git_attr_file_source source, + const char *base, + const char *filename) +{ + int error = 0; + git_buf path = GIT_BUF_INIT; + const char *wd = git_repository_workdir(repo), *relfile; + git_attr_cache *cache = git_repository_attr_cache(repo); + git_attr_file_entry *entry = NULL; + git_attr_file *file = NULL; + + /* join base and path as needed */ + if (base != NULL && git_path_root(filename) < 0) { + if (git_buf_joinpath(&path, base, filename) < 0) + return -1; + filename = path.ptr; + } + + relfile = filename; + if (wd && !git__prefixcmp(relfile, wd)) + relfile += strlen(wd); + + /* check cache for existing entry */ + if ((error = attr_cache_lock(cache)) < 0) + goto cleanup; + + entry = attr_cache_lookup_entry(cache, relfile); + if (!entry) + error = attr_cache_make_entry(&entry, repo, relfile); + else if (entry->file[source] != NULL) { + file = entry->file[source]; + GIT_REFCOUNT_INC(file); + } + + attr_cache_unlock(cache); + +cleanup: + *out_file = file; + *out_entry = entry; + + git_buf_free(&path); + return error; +} + +int git_attr_cache__get( + git_attr_file **out, + git_repository *repo, + git_attr_file_source source, + const char *base, + const char *filename, + git_attr_file_parser parser) +{ + int error = 0; + git_attr_cache *cache = git_repository_attr_cache(repo); + git_attr_file_entry *entry = NULL; + git_attr_file *file = NULL, *updated = NULL; + + if ((error = attr_cache_lookup( + &file, &entry, repo, source, base, filename)) < 0) + return error; + + /* load file if we don't have one or if existing one is out of date */ + if (!file || (error = git_attr_file__out_of_date(repo, file)) > 0) + error = git_attr_file__load(&updated, repo, entry, source, parser); + + /* if we loaded the file, insert into and/or update cache */ + if (updated) { + if ((error = attr_cache_upsert(cache, updated)) < 0) + git_attr_file__free(updated); + else { + git_attr_file__free(file); /* offset incref from lookup */ + file = updated; + } + } + + /* if file could not be loaded */ + if (error < 0) { + /* remove existing entry */ + if (file) { + attr_cache_remove(cache, file); + git_attr_file__free(file); /* offset incref from lookup */ + file = NULL; + } + /* no error if file simply doesn't exist */ + if (error == GIT_ENOTFOUND) { + giterr_clear(); + error = 0; + } + } + + *out = file; + return error; +} + +bool git_attr_cache__is_cached( + git_repository *repo, + git_attr_file_source source, + const char *filename) +{ + git_attr_cache *cache = git_repository_attr_cache(repo); + git_strmap *files; + khiter_t pos; + git_attr_file_entry *entry; + + if (!cache || !(files = cache->files)) + return false; + + pos = git_strmap_lookup_index(files, filename); + if (!git_strmap_valid_index(files, pos)) + return false; + + entry = git_strmap_value_at(files, pos); + + return entry && (entry->file[source] != NULL); +} + + +static int attr_cache__lookup_path( + char **out, git_config *cfg, const char *key, const char *fallback) +{ + git_buf buf = GIT_BUF_INIT; + int error; + const git_config_entry *entry = NULL; + + *out = NULL; + + if ((error = git_config__lookup_entry(&entry, cfg, key, false)) < 0) + return error; + + if (entry) { + const char *cfgval = entry->value; + + /* expand leading ~/ as needed */ + if (cfgval && cfgval[0] == '~' && cfgval[1] == '/' && + !git_sysdir_find_global_file(&buf, &cfgval[2])) + *out = git_buf_detach(&buf); + else if (cfgval) + *out = git__strdup(cfgval); + } + else if (!git_sysdir_find_xdg_file(&buf, fallback)) + *out = git_buf_detach(&buf); + + git_buf_free(&buf); + + return error; +} + +static void attr_cache__free(git_attr_cache *cache) +{ + bool unlock; + + if (!cache) + return; + + unlock = (git_mutex_lock(&cache->lock) == 0); + + if (cache->files != NULL) { + git_attr_file_entry *entry; + git_attr_file *file; + int i; + + git_strmap_foreach_value(cache->files, entry, { + for (i = 0; i < GIT_ATTR_FILE_NUM_SOURCES; ++i) { + if ((file = git__swap(entry->file[i], NULL)) != NULL) { + GIT_REFCOUNT_OWN(file, NULL); + git_attr_file__free(file); + } + } + }); + git_strmap_free(cache->files); + } + + if (cache->macros != NULL) { + git_attr_rule *rule; + + git_strmap_foreach_value(cache->macros, rule, { + git_attr_rule__free(rule); + }); + git_strmap_free(cache->macros); + } + + git_pool_clear(&cache->pool); + + git__free(cache->cfg_attr_file); + cache->cfg_attr_file = NULL; + + git__free(cache->cfg_excl_file); + cache->cfg_excl_file = NULL; + + if (unlock) + git_mutex_unlock(&cache->lock); + git_mutex_free(&cache->lock); + + git__free(cache); +} + +int git_attr_cache__do_init(git_repository *repo) +{ + int ret = 0; + git_attr_cache *cache = git_repository_attr_cache(repo); + git_config *cfg = NULL; + + if (cache) + return 0; + + cache = git__calloc(1, sizeof(git_attr_cache)); + GITERR_CHECK_ALLOC(cache); + + /* set up lock */ + if (git_mutex_init(&cache->lock) < 0) { + giterr_set(GITERR_OS, "Unable to initialize lock for attr cache"); + git__free(cache); + return -1; + } + + if ((ret = git_repository_config_snapshot(&cfg, repo)) < 0) + goto cancel; + + /* cache config settings for attributes and ignores */ + ret = attr_cache__lookup_path( + &cache->cfg_attr_file, cfg, GIT_ATTR_CONFIG, GIT_ATTR_FILE_XDG); + if (ret < 0) + goto cancel; + + ret = attr_cache__lookup_path( + &cache->cfg_excl_file, cfg, GIT_IGNORE_CONFIG, GIT_IGNORE_FILE_XDG); + if (ret < 0) + goto cancel; + + /* allocate hashtable for attribute and ignore file contents, + * hashtable for attribute macros, and string pool + */ + if ((ret = git_strmap_alloc(&cache->files)) < 0 || + (ret = git_strmap_alloc(&cache->macros)) < 0 || + (ret = git_pool_init(&cache->pool, 1, 0)) < 0) + goto cancel; + + cache = git__compare_and_swap(&repo->attrcache, NULL, cache); + if (cache) + goto cancel; /* raced with another thread, free this but no error */ + + git_config_free(cfg); + + /* insert default macros */ + return git_attr_add_macro(repo, "binary", "-diff -crlf -text"); + +cancel: + attr_cache__free(cache); + git_config_free(cfg); + return ret; +} + +void git_attr_cache_flush(git_repository *repo) +{ + git_attr_cache *cache; + + /* this could be done less expensively, but for now, we'll just free + * the entire attrcache and let the next use reinitialize it... + */ + if (repo && (cache = git__swap(repo->attrcache, NULL)) != NULL) + attr_cache__free(cache); +} + +int git_attr_cache__insert_macro(git_repository *repo, git_attr_rule *macro) +{ + git_attr_cache *cache = git_repository_attr_cache(repo); + git_strmap *macros = cache->macros; + int error; + + /* TODO: generate warning log if (macro->assigns.length == 0) */ + if (macro->assigns.length == 0) + return 0; + + if (git_mutex_lock(&cache->lock) < 0) { + giterr_set(GITERR_OS, "Unable to get attr cache lock"); + error = -1; + } else { + git_strmap_insert(macros, macro->match.pattern, macro, error); + git_mutex_unlock(&cache->lock); + } + + return (error < 0) ? -1 : 0; +} + +git_attr_rule *git_attr_cache__lookup_macro( + git_repository *repo, const char *name) +{ + git_strmap *macros = git_repository_attr_cache(repo)->macros; + khiter_t pos; + + pos = git_strmap_lookup_index(macros, name); + + if (!git_strmap_valid_index(macros, pos)) + return NULL; + + return (git_attr_rule *)git_strmap_value_at(macros, pos); +} + |