diff options
| -rw-r--r-- | src/bftw.c | 131 |
1 files changed, 82 insertions, 49 deletions
@@ -461,8 +461,12 @@ struct bftw_state { /** The cache of open directories. */ struct bftw_cache cache; + /** The async I/O queue. */ struct ioq *ioq; + /** The number of I/O threads. */ + size_t nthreads; + /** The queue of directories to read. */ struct bftw_list dirs; /** The queue of files to visit. */ @@ -536,6 +540,7 @@ static int bftw_state_init(struct bftw_state *state, const struct bftw_args *arg return -1; } } + state->nthreads = nthreads; SLIST_INIT(&state->dirs); SLIST_INIT(&state->files); @@ -889,13 +894,81 @@ static enum bftw_action bftw_call_back(struct bftw_state *state, const char *nam } } +/** Pop a response from the I/O queue. */ +static int bftw_ioq_pop(struct bftw_state *state, bool block) { + struct ioq *ioq = state->ioq; + if (!ioq) { + return -1; + } + + struct ioq_res *res = block ? ioq_pop(ioq) : ioq_trypop(ioq); + if (!res) { + return -1; + } + + struct bftw_cache *cache = &state->cache; + ++cache->capacity; + + struct bftw_file *file = res->ptr; + file->ioqueued = false; + + if (file->parent) { + bftw_cache_unpin(cache, file->parent); + } + + if (res->error) { + arena_free(&cache->dirs, res->dir); + } else { + bftw_file_set_dir(cache, file, res->dir); + } + + ioq_free(ioq, res); + + if (!(state->flags & BFTW_SORT)) { + SLIST_PREPEND(&state->dirs, file); + } + + return 0; +} + +/** Try to reserve space in the I/O queue. */ +static int bftw_ioq_reserve(struct bftw_state *state) { + struct ioq *ioq = state->ioq; + if (!ioq) { + return -1; + } + + if (ioq_capacity(ioq) > 0) { + return 0; + } + + // With more than two threads, it is faster to wait for an I/O operation + // to complete than it is to do it ourselves + bool block = state->nthreads > 2; + if (bftw_ioq_pop(state, block) < 0) { + return -1; + } + + return 0; +} + +/** Try to reserve space in the cache. */ +static int bftw_cache_reserve(struct bftw_state *state) { + struct bftw_cache *cache = &state->cache; + if (cache->capacity > 0) { + return 0; + } + + return bftw_cache_pop(cache); +} + /** Push a directory onto the queue. */ static void bftw_push_dir(struct bftw_state *state, struct bftw_file *file) { bfs_assert(file->type == BFS_DIR); struct bftw_cache *cache = &state->cache; - if (!state->ioq) { + if (bftw_ioq_reserve(state) != 0) { goto append; } @@ -908,13 +981,11 @@ static void bftw_push_dir(struct bftw_state *state, struct bftw_file *file) { bftw_cache_pin(cache, file->parent); } - if (cache->capacity == 0) { - if (bftw_cache_pop(cache) != 0) { - goto unpin; - } + if (bftw_cache_reserve(state) != 0) { + goto unpin; } - struct bfs_dir *dir = arena_alloc(&state->cache.dirs); + struct bfs_dir *dir = arena_alloc(&cache->dirs); if (!dir) { goto unpin; } @@ -927,13 +998,17 @@ static void bftw_push_dir(struct bftw_state *state, struct bftw_file *file) { --cache->capacity; if (state->flags & BFTW_SORT) { + // When sorting, dirs are always kept in order in state->dirs, + // and we wait for the ioq to open them before popping goto append; } else { + // When not sorting, dirs are not added to state->dirs until + // popped from the ioq return; } free: - arena_free(&state->cache.dirs, dir); + arena_free(&cache->dirs, dir); unpin: if (file->parent) { bftw_cache_unpin(cache, file->parent); @@ -942,48 +1017,6 @@ append: SLIST_APPEND(&state->dirs, file); } -/** Pop a response from the I/O queue. */ -static int bftw_ioq_pop(struct bftw_state *state, bool block) { - if (!state->ioq) { - return -1; - } - - struct ioq_res *res; - if (block) { - res = ioq_pop(state->ioq); - } else { - res = ioq_trypop(state->ioq); - } - - if (!res) { - return -1; - } - - struct bftw_cache *cache = &state->cache; - ++cache->capacity; - - struct bftw_file *file = res->ptr; - file->ioqueued = false; - - if (file->parent) { - bftw_cache_unpin(cache, file->parent); - } - - if (res->error) { - arena_free(&state->cache.dirs, res->dir); - } else { - bftw_file_set_dir(cache, file, res->dir); - } - - ioq_free(state->ioq, res); - - if (!(state->flags & BFTW_SORT)) { - SLIST_PREPEND(&state->dirs, file); - } - - return 0; -} - /** Pop a directory to read from the queue. */ static bool bftw_pop_dir(struct bftw_state *state) { bfs_assert(!state->file); |