util: import cache.c/h from glsl
It's not dependent on GLSL and it can be useful for shader caches that don't deal with GLSL. v2: address review comments v3: keep the other 3 lines in configure.ac Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
This commit is contained in:
Marek Olšák
712
src/util/disk_cache.c
Normal file
712
src/util/disk_cache.c
Normal file
@@ -0,0 +1,712 @@
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/*
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* Copyright © 2014 Intel Corporation
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice (including the next
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* paragraph) shall be included in all copies or substantial portions of the
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* Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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#ifdef ENABLE_SHADER_CACHE
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#include <ctype.h>
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#include <string.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <sys/file.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/mman.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <pwd.h>
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#include <errno.h>
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#include <dirent.h>
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#include "util/u_atomic.h"
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#include "util/mesa-sha1.h"
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#include "util/ralloc.h"
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#include "main/errors.h"
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#include "disk_cache.h"
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/* Number of bits to mask off from a cache key to get an index. */
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#define CACHE_INDEX_KEY_BITS 16
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/* Mask for computing an index from a key. */
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#define CACHE_INDEX_KEY_MASK ((1 << CACHE_INDEX_KEY_BITS) - 1)
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/* The number of keys that can be stored in the index. */
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#define CACHE_INDEX_MAX_KEYS (1 << CACHE_INDEX_KEY_BITS)
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struct program_cache {
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/* The path to the cache directory. */
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char *path;
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/* A pointer to the mmapped index file within the cache directory. */
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uint8_t *index_mmap;
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size_t index_mmap_size;
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/* Pointer to total size of all objects in cache (within index_mmap) */
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uint64_t *size;
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/* Pointer to stored keys, (within index_mmap). */
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uint8_t *stored_keys;
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/* Maximum size of all cached objects (in bytes). */
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uint64_t max_size;
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};
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/* Create a directory named 'path' if it does not already exist.
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*
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* Returns: 0 if path already exists as a directory or if created.
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* -1 in all other cases.
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*/
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static int
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mkdir_if_needed(char *path)
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{
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struct stat sb;
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/* If the path exists already, then our work is done if it's a
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* directory, but it's an error if it is not.
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*/
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if (stat(path, &sb) == 0) {
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if (S_ISDIR(sb.st_mode)) {
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return 0;
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} else {
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fprintf(stderr, "Cannot use %s for shader cache (not a directory)"
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"---disabling.\n", path);
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return -1;
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}
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}
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int ret = mkdir(path, 0755);
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if (ret == 0 || (ret == -1 && errno == EEXIST))
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return 0;
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fprintf(stderr, "Failed to create %s for shader cache (%s)---disabling.\n",
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path, strerror(errno));
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return -1;
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}
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/* Concatenate an existing path and a new name to form a new path. If the new
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* path does not exist as a directory, create it then return the resulting
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* name of the new path (ralloc'ed off of 'ctx').
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*
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* Returns NULL on any error, such as:
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*
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* <path> does not exist or is not a directory
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* <path>/<name> exists but is not a directory
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* <path>/<name> cannot be created as a directory
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*/
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static char *
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concatenate_and_mkdir(void *ctx, char *path, char *name)
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{
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char *new_path;
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struct stat sb;
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if (stat(path, &sb) != 0 || ! S_ISDIR(sb.st_mode))
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return NULL;
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new_path = ralloc_asprintf(ctx, "%s/%s", path, name);
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if (mkdir_if_needed(new_path) == 0)
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return new_path;
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else
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return NULL;
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}
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struct program_cache *
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cache_create(void)
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{
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void *local;
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struct program_cache *cache = NULL;
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char *path, *max_size_str;
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uint64_t max_size;
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int fd = -1;
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struct stat sb;
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size_t size;
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/* A ralloc context for transient data during this invocation. */
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local = ralloc_context(NULL);
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if (local == NULL)
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goto fail;
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/* At user request, disable shader cache entirely. */
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if (getenv("MESA_GLSL_CACHE_DISABLE"))
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goto fail;
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/* Determine path for cache based on the first defined name as follows:
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*
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* $MESA_GLSL_CACHE_DIR
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* $XDG_CACHE_HOME/mesa
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* <pwd.pw_dir>/.cache/mesa
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*/
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path = getenv("MESA_GLSL_CACHE_DIR");
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if (path && mkdir_if_needed(path) == -1) {
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goto fail;
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}
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if (path == NULL) {
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char *xdg_cache_home = getenv("XDG_CACHE_HOME");
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if (xdg_cache_home) {
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if (mkdir_if_needed(xdg_cache_home) == -1)
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goto fail;
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path = concatenate_and_mkdir(local, xdg_cache_home, "mesa");
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if (path == NULL)
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goto fail;
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}
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}
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if (path == NULL) {
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char *buf;
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size_t buf_size;
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struct passwd pwd, *result;
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buf_size = sysconf(_SC_GETPW_R_SIZE_MAX);
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if (buf_size == -1)
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buf_size = 512;
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/* Loop until buf_size is large enough to query the directory */
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while (1) {
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buf = ralloc_size(local, buf_size);
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getpwuid_r(getuid(), &pwd, buf, buf_size, &result);
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if (result)
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break;
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if (errno == ERANGE) {
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ralloc_free(buf);
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buf = NULL;
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buf_size *= 2;
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} else {
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goto fail;
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}
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}
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path = concatenate_and_mkdir(local, pwd.pw_dir, ".cache");
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if (path == NULL)
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goto fail;
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path = concatenate_and_mkdir(local, path, "mesa");
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if (path == NULL)
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goto fail;
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}
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cache = ralloc(NULL, struct program_cache);
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if (cache == NULL)
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goto fail;
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cache->path = ralloc_strdup(cache, path);
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if (cache->path == NULL)
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goto fail;
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path = ralloc_asprintf(local, "%s/index", cache->path);
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if (path == NULL)
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goto fail;
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fd = open(path, O_RDWR | O_CREAT | O_CLOEXEC, 0644);
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if (fd == -1)
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goto fail;
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if (fstat(fd, &sb) == -1)
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goto fail;
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/* Force the index file to be the expected size. */
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size = sizeof(*cache->size) + CACHE_INDEX_MAX_KEYS * CACHE_KEY_SIZE;
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if (sb.st_size != size) {
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if (ftruncate(fd, size) == -1)
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goto fail;
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}
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/* We map this shared so that other processes see updates that we
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* make.
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*
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* Note: We do use atomic addition to ensure that multiple
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* processes don't scramble the cache size recorded in the
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* index. But we don't use any locking to prevent multiple
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* processes from updating the same entry simultaneously. The idea
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* is that if either result lands entirely in the index, then
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* that's equivalent to a well-ordered write followed by an
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* eviction and a write. On the other hand, if the simultaneous
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* writes result in a corrupt entry, that's not really any
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* different than both entries being evicted, (since within the
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* guarantees of the cryptographic hash, a corrupt entry is
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* unlikely to ever match a real cache key).
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*/
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cache->index_mmap = mmap(NULL, size, PROT_READ | PROT_WRITE,
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MAP_SHARED, fd, 0);
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if (cache->index_mmap == MAP_FAILED)
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goto fail;
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cache->index_mmap_size = size;
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close(fd);
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cache->size = (uint64_t *) cache->index_mmap;
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cache->stored_keys = cache->index_mmap + sizeof(uint64_t);
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max_size = 0;
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max_size_str = getenv("MESA_GLSL_CACHE_MAX_SIZE");
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if (max_size_str) {
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char *end;
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max_size = strtoul(max_size_str, &end, 10);
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if (end == max_size_str) {
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max_size = 0;
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} else {
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while (*end && isspace(*end))
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end++;
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switch (*end) {
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case 'K':
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case 'k':
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max_size *= 1024;
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break;
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case 'M':
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case 'm':
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max_size *= 1024*1024;
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break;
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case '\0':
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case 'G':
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case 'g':
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default:
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max_size *= 1024*1024*1024;
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break;
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}
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}
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}
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/* Default to 1GB for maximum cache size. */
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if (max_size == 0)
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max_size = 1024*1024*1024;
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cache->max_size = max_size;
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ralloc_free(local);
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return cache;
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fail:
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if (fd != -1)
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close(fd);
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if (cache)
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ralloc_free(cache);
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ralloc_free(local);
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return NULL;
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}
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void
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cache_destroy(struct program_cache *cache)
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||||
{
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munmap(cache->index_mmap, cache->index_mmap_size);
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||||
ralloc_free(cache);
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}
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/* Return a filename within the cache's directory corresponding to 'key'. The
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* returned filename is ralloced with 'cache' as the parent context.
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*
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* Returns NULL if out of memory.
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*/
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||||
static char *
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||||
get_cache_file(struct program_cache *cache, cache_key key)
|
||||
{
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||||
char buf[41];
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||||
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||||
_mesa_sha1_format(buf, key);
|
||||
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||||
return ralloc_asprintf(cache, "%s/%c%c/%s",
|
||||
cache->path, buf[0], buf[1], buf + 2);
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||||
}
|
||||
|
||||
/* Create the directory that will be needed for the cache file for \key.
|
||||
*
|
||||
* Obviously, the implementation here must closely match
|
||||
* _get_cache_file above.
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||||
*/
|
||||
static void
|
||||
make_cache_file_directory(struct program_cache *cache, cache_key key)
|
||||
{
|
||||
char *dir;
|
||||
char buf[41];
|
||||
|
||||
_mesa_sha1_format(buf, key);
|
||||
|
||||
dir = ralloc_asprintf(cache, "%s/%c%c", cache->path, buf[0], buf[1]);
|
||||
|
||||
mkdir_if_needed(dir);
|
||||
|
||||
ralloc_free(dir);
|
||||
}
|
||||
|
||||
/* Given a directory path and predicate function, count all entries in
|
||||
* that directory for which the predicate returns true. Then choose a
|
||||
* random entry from among those counted.
|
||||
*
|
||||
* Returns: A malloc'ed string for the path to the chosen file, (or
|
||||
* NULL on any error). The caller should free the string when
|
||||
* finished.
|
||||
*/
|
||||
static char *
|
||||
choose_random_file_matching(const char *dir_path,
|
||||
bool (*predicate)(struct dirent *))
|
||||
{
|
||||
DIR *dir;
|
||||
struct dirent *entry;
|
||||
unsigned int count, victim;
|
||||
char *filename;
|
||||
|
||||
dir = opendir(dir_path);
|
||||
if (dir == NULL)
|
||||
return NULL;
|
||||
|
||||
count = 0;
|
||||
|
||||
while (1) {
|
||||
entry = readdir(dir);
|
||||
if (entry == NULL)
|
||||
break;
|
||||
if (! predicate(entry))
|
||||
continue;
|
||||
|
||||
count++;
|
||||
}
|
||||
|
||||
if (count == 0) {
|
||||
closedir(dir);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
victim = rand() % count;
|
||||
|
||||
rewinddir(dir);
|
||||
count = 0;
|
||||
|
||||
while (1) {
|
||||
entry = readdir(dir);
|
||||
if (entry == NULL)
|
||||
break;
|
||||
if (! predicate(entry))
|
||||
continue;
|
||||
if (count == victim)
|
||||
break;
|
||||
|
||||
count++;
|
||||
}
|
||||
|
||||
if (entry == NULL) {
|
||||
closedir(dir);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
if (asprintf(&filename, "%s/%s", dir_path, entry->d_name) < 0)
|
||||
filename = NULL;
|
||||
|
||||
closedir(dir);
|
||||
|
||||
return filename;
|
||||
}
|
||||
|
||||
/* Is entry a regular file, and not having a name with a trailing
|
||||
* ".tmp"
|
||||
*/
|
||||
static bool
|
||||
is_regular_non_tmp_file(struct dirent *entry)
|
||||
{
|
||||
size_t len;
|
||||
|
||||
if (entry->d_type != DT_REG)
|
||||
return false;
|
||||
|
||||
len = strlen (entry->d_name);
|
||||
if (len >= 4 && strcmp(&entry->d_name[len-4], ".tmp") == 0)
|
||||
return false;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
/* Returns the size of the deleted file, (or 0 on any error). */
|
||||
static size_t
|
||||
unlink_random_file_from_directory(const char *path)
|
||||
{
|
||||
struct stat sb;
|
||||
char *filename;
|
||||
|
||||
filename = choose_random_file_matching(path, is_regular_non_tmp_file);
|
||||
if (filename == NULL)
|
||||
return 0;
|
||||
|
||||
if (stat(filename, &sb) == -1) {
|
||||
free (filename);
|
||||
return 0;
|
||||
}
|
||||
|
||||
unlink(filename);
|
||||
|
||||
free (filename);
|
||||
|
||||
return sb.st_size;
|
||||
}
|
||||
|
||||
/* Is entry a directory with a two-character name, (and not the
|
||||
* special name of "..")
|
||||
*/
|
||||
static bool
|
||||
is_two_character_sub_directory(struct dirent *entry)
|
||||
{
|
||||
if (entry->d_type != DT_DIR)
|
||||
return false;
|
||||
|
||||
if (strlen(entry->d_name) != 2)
|
||||
return false;
|
||||
|
||||
if (strcmp(entry->d_name, "..") == 0)
|
||||
return false;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
static void
|
||||
evict_random_item(struct program_cache *cache)
|
||||
{
|
||||
const char hex[] = "0123456789abcde";
|
||||
char *dir_path;
|
||||
int a, b;
|
||||
size_t size;
|
||||
|
||||
/* With a reasonably-sized, full cache, (and with keys generated
|
||||
* from a cryptographic hash), we can choose two random hex digits
|
||||
* and reasonably expect the directory to exist with a file in it.
|
||||
*/
|
||||
a = rand() % 16;
|
||||
b = rand() % 16;
|
||||
|
||||
if (asprintf(&dir_path, "%s/%c%c", cache->path, hex[a], hex[b]) < 0)
|
||||
return;
|
||||
|
||||
size = unlink_random_file_from_directory(dir_path);
|
||||
|
||||
free(dir_path);
|
||||
|
||||
if (size) {
|
||||
p_atomic_add(cache->size, - size);
|
||||
return;
|
||||
}
|
||||
|
||||
/* In the case where the random choice of directory didn't find
|
||||
* something, we choose randomly from the existing directories.
|
||||
*
|
||||
* Really, the only reason this code exists is to allow the unit
|
||||
* tests to work, (which use an artificially-small cache to be able
|
||||
* to force a single cached item to be evicted).
|
||||
*/
|
||||
dir_path = choose_random_file_matching(cache->path,
|
||||
is_two_character_sub_directory);
|
||||
if (dir_path == NULL)
|
||||
return;
|
||||
|
||||
size = unlink_random_file_from_directory(dir_path);
|
||||
|
||||
free(dir_path);
|
||||
|
||||
if (size)
|
||||
p_atomic_add(cache->size, - size);
|
||||
}
|
||||
|
||||
void
|
||||
cache_put(struct program_cache *cache,
|
||||
cache_key key,
|
||||
const void *data,
|
||||
size_t size)
|
||||
{
|
||||
int fd = -1, fd_final = -1, err, ret;
|
||||
size_t len;
|
||||
char *filename = NULL, *filename_tmp = NULL;
|
||||
const char *p = data;
|
||||
|
||||
filename = get_cache_file(cache, key);
|
||||
if (filename == NULL)
|
||||
goto done;
|
||||
|
||||
/* Write to a temporary file to allow for an atomic rename to the
|
||||
* final destination filename, (to prevent any readers from seeing
|
||||
* a partially written file).
|
||||
*/
|
||||
filename_tmp = ralloc_asprintf(cache, "%s.tmp", filename);
|
||||
if (filename_tmp == NULL)
|
||||
goto done;
|
||||
|
||||
fd = open(filename_tmp, O_WRONLY | O_CLOEXEC | O_CREAT, 0644);
|
||||
|
||||
/* Make the two-character subdirectory within the cache as needed. */
|
||||
if (fd == -1) {
|
||||
if (errno != ENOENT)
|
||||
goto done;
|
||||
|
||||
make_cache_file_directory(cache, key);
|
||||
|
||||
fd = open(filename_tmp, O_WRONLY | O_CLOEXEC | O_CREAT, 0644);
|
||||
if (fd == -1)
|
||||
goto done;
|
||||
}
|
||||
|
||||
/* With the temporary file open, we take an exclusive flock on
|
||||
* it. If the flock fails, then another process still has the file
|
||||
* open with the flock held. So just let that file be responsible
|
||||
* for writing the file.
|
||||
*/
|
||||
err = flock(fd, LOCK_EX | LOCK_NB);
|
||||
if (err == -1)
|
||||
goto done;
|
||||
|
||||
/* Now that we have the lock on the open temporary file, we can
|
||||
* check to see if the destination file already exists. If so,
|
||||
* another process won the race between when we saw that the file
|
||||
* didn't exist and now. In this case, we don't do anything more,
|
||||
* (to ensure the size accounting of the cache doesn't get off).
|
||||
*/
|
||||
fd_final = open(filename, O_RDONLY | O_CLOEXEC);
|
||||
if (fd_final != -1)
|
||||
goto done;
|
||||
|
||||
/* OK, we're now on the hook to write out a file that we know is
|
||||
* not in the cache, and is also not being written out to the cache
|
||||
* by some other process.
|
||||
*
|
||||
* Before we do that, if the cache is too large, evict something
|
||||
* else first.
|
||||
*/
|
||||
if (*cache->size + size > cache->max_size)
|
||||
evict_random_item(cache);
|
||||
|
||||
/* Now, finally, write out the contents to the temporary file, then
|
||||
* rename them atomically to the destination filename, and also
|
||||
* perform an atomic increment of the total cache size.
|
||||
*/
|
||||
for (len = 0; len < size; len += ret) {
|
||||
ret = write(fd, p + len, size - len);
|
||||
if (ret == -1) {
|
||||
unlink(filename_tmp);
|
||||
goto done;
|
||||
}
|
||||
}
|
||||
|
||||
rename(filename_tmp, filename);
|
||||
|
||||
p_atomic_add(cache->size, size);
|
||||
|
||||
/* This close finally releases the flock, (now that the final dile
|
||||
* has been renamed into place and the size has been added).
|
||||
*/
|
||||
close(fd);
|
||||
fd = -1;
|
||||
|
||||
done:
|
||||
if (filename_tmp)
|
||||
ralloc_free(filename_tmp);
|
||||
if (filename)
|
||||
ralloc_free(filename);
|
||||
if (fd != -1)
|
||||
close(fd);
|
||||
}
|
||||
|
||||
void *
|
||||
cache_get(struct program_cache *cache, cache_key key, size_t *size)
|
||||
{
|
||||
int fd = -1, ret, len;
|
||||
struct stat sb;
|
||||
char *filename = NULL;
|
||||
uint8_t *data = NULL;
|
||||
|
||||
if (size)
|
||||
*size = 0;
|
||||
|
||||
filename = get_cache_file(cache, key);
|
||||
if (filename == NULL)
|
||||
goto fail;
|
||||
|
||||
fd = open(filename, O_RDONLY | O_CLOEXEC);
|
||||
if (fd == -1)
|
||||
goto fail;
|
||||
|
||||
if (fstat(fd, &sb) == -1)
|
||||
goto fail;
|
||||
|
||||
data = malloc(sb.st_size);
|
||||
if (data == NULL)
|
||||
goto fail;
|
||||
|
||||
for (len = 0; len < sb.st_size; len += ret) {
|
||||
ret = read(fd, data + len, sb.st_size - len);
|
||||
if (ret == -1)
|
||||
goto fail;
|
||||
}
|
||||
|
||||
ralloc_free(filename);
|
||||
close(fd);
|
||||
|
||||
if (size)
|
||||
*size = sb.st_size;
|
||||
|
||||
return data;
|
||||
|
||||
fail:
|
||||
if (data)
|
||||
free(data);
|
||||
if (filename)
|
||||
ralloc_free(filename);
|
||||
if (fd != -1)
|
||||
close(fd);
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
void
|
||||
cache_put_key(struct program_cache *cache, cache_key key)
|
||||
{
|
||||
uint32_t *key_chunk = (uint32_t *) key;
|
||||
int i = *key_chunk & CACHE_INDEX_KEY_MASK;
|
||||
unsigned char *entry;
|
||||
|
||||
entry = &cache->stored_keys[i + CACHE_KEY_SIZE];
|
||||
|
||||
memcpy(entry, key, CACHE_KEY_SIZE);
|
||||
}
|
||||
|
||||
/* This function lets us test whether a given key was previously
|
||||
* stored in the cache with cache_put_key(). The implement is
|
||||
* efficient by not using syscalls or hitting the disk. It's not
|
||||
* race-free, but the races are benign. If we race with someone else
|
||||
* calling cache_put_key, then that's just an extra cache miss and an
|
||||
* extra recompile.
|
||||
*/
|
||||
bool
|
||||
cache_has_key(struct program_cache *cache, cache_key key)
|
||||
{
|
||||
uint32_t *key_chunk = (uint32_t *) key;
|
||||
int i = *key_chunk & CACHE_INDEX_KEY_MASK;
|
||||
unsigned char *entry;
|
||||
|
||||
entry = &cache->stored_keys[i + CACHE_KEY_SIZE];
|
||||
|
||||
return memcmp(entry, key, CACHE_KEY_SIZE) == 0;
|
||||
}
|
||||
|
||||
#endif
|
||||
Reference in New Issue
Block a user