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/*
* Copyright © 2014 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifdef ENABLE_SHADER_CACHE
#include <ctype.h>
#include <ftw.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/file.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <pwd.h>
#include <errno.h>
#include <dirent.h>
#include <inttypes.h>
#include "zlib.h"
#ifdef HAVE_ZSTD
#include "zstd.h"
#endif
#include "util/crc32.h"
#include "util/debug.h"
#include "util/rand_xor.h"
#include "util/u_atomic.h"
#include "util/u_queue.h"
#include "util/mesa-sha1.h"
#include "util/ralloc.h"
#include "util/compiler.h"
#include "disk_cache.h"
/* Number of bits to mask off from a cache key to get an index. */
#define CACHE_INDEX_KEY_BITS 16
/* Mask for computing an index from a key. */
#define CACHE_INDEX_KEY_MASK ((1 << CACHE_INDEX_KEY_BITS) - 1)
/* The number of keys that can be stored in the index. */
#define CACHE_INDEX_MAX_KEYS (1 << CACHE_INDEX_KEY_BITS)
/* The cache version should be bumped whenever a change is made to the
* structure of cache entries or the index. This will give any 3rd party
* applications reading the cache entries a chance to adjust to the changes.
*
* - The cache version is checked internally when reading a cache entry. If we
* ever have a mismatch we are in big trouble as this means we had a cache
* collision. In case of such an event please check the skys for giant
* asteroids and that the entire Mesa team hasn't been eaten by wolves.
*
* - There is no strict requirement that cache versions be backwards
* compatible but effort should be taken to limit disruption where possible.
*/
#define CACHE_VERSION 1
/* 3 is the recomended level, with 22 as the absolute maximum */
#define ZSTD_COMPRESSION_LEVEL 3
struct disk_cache {
/* The path to the cache directory. */
char *path;
bool path_init_failed;
/* Thread queue for compressing and writing cache entries to disk */
struct util_queue cache_queue;
/* Seed for rand, which is used to pick a random directory */
uint64_t seed_xorshift128plus[2];
/* A pointer to the mmapped index file within the cache directory. */
uint8_t *index_mmap;
size_t index_mmap_size;
/* Pointer to total size of all objects in cache (within index_mmap) */
uint64_t *size;
/* Pointer to stored keys, (within index_mmap). */
uint8_t *stored_keys;
/* Maximum size of all cached objects (in bytes). */
uint64_t max_size;
/* Driver cache keys. */
uint8_t *driver_keys_blob;
size_t driver_keys_blob_size;
disk_cache_put_cb blob_put_cb;
disk_cache_get_cb blob_get_cb;
};
struct disk_cache_put_job {
struct util_queue_fence fence;
struct disk_cache *cache;
cache_key key;
/* Copy of cache data to be compressed and written. */
void *data;
/* Size of data to be compressed and written. */
size_t size;
struct cache_item_metadata cache_item_metadata;
};
/* Create a directory named 'path' if it does not already exist.
*
* Returns: 0 if path already exists as a directory or if created.
* -1 in all other cases.
*/
static int
mkdir_if_needed(const char *path)
{
struct stat sb;
/* If the path exists already, then our work is done if it's a
* directory, but it's an error if it is not.
*/
if (stat(path, &sb) == 0) {
if (S_ISDIR(sb.st_mode)) {
return 0;
} else {
fprintf(stderr, "Cannot use %s for shader cache (not a directory)"
"---disabling.\n", path);
return -1;
}
}
int ret = mkdir(path, 0755);
if (ret == 0 || (ret == -1 && errno == EEXIST))
return 0;
fprintf(stderr, "Failed to create %s for shader cache (%s)---disabling.\n",
path, strerror(errno));
return -1;
}
/* Concatenate an existing path and a new name to form a new path. If the new
* path does not exist as a directory, create it then return the resulting
* name of the new path (ralloc'ed off of 'ctx').
*
* Returns NULL on any error, such as:
*
* <path> does not exist or is not a directory
* <path>/<name> exists but is not a directory
* <path>/<name> cannot be created as a directory
*/
static char *
concatenate_and_mkdir(void *ctx, const char *path, const char *name)
{
char *new_path;
struct stat sb;
if (stat(path, &sb) != 0 || ! S_ISDIR(sb.st_mode))
return NULL;
new_path = ralloc_asprintf(ctx, "%s/%s", path, name);
if (mkdir_if_needed(new_path) == 0)
return new_path;
else
return NULL;
}
#define DRV_KEY_CPY(_dst, _src, _src_size) \
do { \
memcpy(_dst, _src, _src_size); \
_dst += _src_size; \
} while (0);
struct disk_cache *
disk_cache_create(const char *gpu_name, const char *driver_id,
uint64_t driver_flags)
{
void *local;
struct disk_cache *cache = NULL;
char *path, *max_size_str;
uint64_t max_size;
int fd = -1;
struct stat sb;
size_t size;
uint8_t cache_version = CACHE_VERSION;
size_t cv_size = sizeof(cache_version);
/* If running as a users other than the real user disable cache */
if (geteuid() != getuid())
return NULL;
/* A ralloc context for transient data during this invocation. */
local = ralloc_context(NULL);
if (local == NULL)
goto fail;
/* At user request, disable shader cache entirely. */
if (env_var_as_boolean("MESA_GLSL_CACHE_DISABLE", false))
goto fail;
cache = rzalloc(NULL, struct disk_cache);
if (cache == NULL)
goto fail;
/* Assume failure. */
cache->path_init_failed = true;
/* Determine path for cache based on the first defined name as follows:
*
* $MESA_GLSL_CACHE_DIR
* $XDG_CACHE_HOME/mesa_shader_cache
* <pwd.pw_dir>/.cache/mesa_shader_cache
*/
path = getenv("MESA_GLSL_CACHE_DIR");
if (path) {
if (mkdir_if_needed(path) == -1)
goto path_fail;
path = concatenate_and_mkdir(local, path, CACHE_DIR_NAME);
if (path == NULL)
goto path_fail;
}
if (path == NULL) {
char *xdg_cache_home = getenv("XDG_CACHE_HOME");
if (xdg_cache_home) {
if (mkdir_if_needed(xdg_cache_home) == -1)
goto path_fail;
path = concatenate_and_mkdir(local, xdg_cache_home, CACHE_DIR_NAME);
if (path == NULL)
goto path_fail;
}
}
if (path == NULL) {
char *buf;
size_t buf_size;
struct passwd pwd, *result;
buf_size = sysconf(_SC_GETPW_R_SIZE_MAX);
if (buf_size == -1)
buf_size = 512;
/* Loop until buf_size is large enough to query the directory */
while (1) {
buf = ralloc_size(local, buf_size);
getpwuid_r(getuid(), &pwd, buf, buf_size, &result);
if (result)
break;
if (errno == ERANGE) {
ralloc_free(buf);
buf = NULL;
buf_size *= 2;
} else {
goto path_fail;
}
}
path = concatenate_and_mkdir(local, pwd.pw_dir, ".cache");
if (path == NULL)
goto path_fail;
path = concatenate_and_mkdir(local, path, CACHE_DIR_NAME);
if (path == NULL)
goto path_fail;
}
cache->path = ralloc_strdup(cache, path);
if (cache->path == NULL)
goto path_fail;
path = ralloc_asprintf(local, "%s/index", cache->path);
if (path == NULL)
goto path_fail;
fd = open(path, O_RDWR | O_CREAT | O_CLOEXEC, 0644);
if (fd == -1)
goto path_fail;
if (fstat(fd, &sb) == -1)
goto path_fail;
/* Force the index file to be the expected size. */
size = sizeof(*cache->size) + CACHE_INDEX_MAX_KEYS * CACHE_KEY_SIZE;
if (sb.st_size != size) {
if (ftruncate(fd, size) == -1)
goto path_fail;
}
/* We map this shared so that other processes see updates that we
* make.
*
* Note: We do use atomic addition to ensure that multiple
* processes don't scramble the cache size recorded in the
* index. But we don't use any locking to prevent multiple
* processes from updating the same entry simultaneously. The idea
* is that if either result lands entirely in the index, then
* that's equivalent to a well-ordered write followed by an
* eviction and a write. On the other hand, if the simultaneous
* writes result in a corrupt entry, that's not really any
* different than both entries being evicted, (since within the
* guarantees of the cryptographic hash, a corrupt entry is
* unlikely to ever match a real cache key).
*/
cache->index_mmap = mmap(NULL, size, PROT_READ | PROT_WRITE,
MAP_SHARED, fd, 0);
if (cache->index_mmap == MAP_FAILED)
goto path_fail;
cache->index_mmap_size = size;
cache->size = (uint64_t *) cache->index_mmap;
cache->stored_keys = cache->index_mmap + sizeof(uint64_t);
max_size = 0;
max_size_str = getenv("MESA_GLSL_CACHE_MAX_SIZE");
if (max_size_str) {
char *end;
max_size = strtoul(max_size_str, &end, 10);
if (end == max_size_str) {
max_size = 0;
} else {
switch (*end) {
case 'K':
case 'k':
max_size *= 1024;
break;
case 'M':
case 'm':
max_size *= 1024*1024;
break;
case '\0':
case 'G':
case 'g':
default:
max_size *= 1024*1024*1024;
break;
}
}
}
/* Default to 1GB for maximum cache size. */
if (max_size == 0) {
max_size = 1024*1024*1024;
}
cache->max_size = max_size;
/* 4 threads were chosen below because just about all modern CPUs currently
* available that run Mesa have *at least* 4 cores. For these CPUs allowing
* more threads can result in the queue being processed faster, thus
* avoiding excessive memory use due to a backlog of cache entrys building
* up in the queue. Since we set the UTIL_QUEUE_INIT_USE_MINIMUM_PRIORITY
* flag this should have little negative impact on low core systems.
*
* The queue will resize automatically when it's full, so adding new jobs
* doesn't stall.
*/
util_queue_init(&cache->cache_queue, "disk$", 32, 4,
UTIL_QUEUE_INIT_RESIZE_IF_FULL |
UTIL_QUEUE_INIT_USE_MINIMUM_PRIORITY |
UTIL_QUEUE_INIT_SET_FULL_THREAD_AFFINITY);
cache->path_init_failed = false;
path_fail:
if (fd != -1)
close(fd);
cache->driver_keys_blob_size = cv_size;
/* Create driver id keys */
size_t id_size = strlen(driver_id) + 1;
size_t gpu_name_size = strlen(gpu_name) + 1;
cache->driver_keys_blob_size += id_size;
cache->driver_keys_blob_size += gpu_name_size;
/* We sometimes store entire structs that contains a pointers in the cache,
* use pointer size as a key to avoid hard to debug issues.
*/
uint8_t ptr_size = sizeof(void *);
size_t ptr_size_size = sizeof(ptr_size);
cache->driver_keys_blob_size += ptr_size_size;
size_t driver_flags_size = sizeof(driver_flags);
cache->driver_keys_blob_size += driver_flags_size;
cache->driver_keys_blob =
ralloc_size(cache, cache->driver_keys_blob_size);
if (!cache->driver_keys_blob)
goto fail;
uint8_t *drv_key_blob = cache->driver_keys_blob;
DRV_KEY_CPY(drv_key_blob, &cache_version, cv_size)
DRV_KEY_CPY(drv_key_blob, driver_id, id_size)
DRV_KEY_CPY(drv_key_blob, gpu_name, gpu_name_size)
DRV_KEY_CPY(drv_key_blob, &ptr_size, ptr_size_size)
DRV_KEY_CPY(drv_key_blob, &driver_flags, driver_flags_size)
/* Seed our rand function */
s_rand_xorshift128plus(cache->seed_xorshift128plus, true);
ralloc_free(local);
return cache;
fail:
if (cache)
ralloc_free(cache);
ralloc_free(local);
return NULL;
}
void
disk_cache_destroy(struct disk_cache *cache)
{
if (cache && !cache->path_init_failed) {
util_queue_finish(&cache->cache_queue);
util_queue_destroy(&cache->cache_queue);
munmap(cache->index_mmap, cache->index_mmap_size);
}
ralloc_free(cache);
}
void
disk_cache_wait_for_idle(struct disk_cache *cache)
{
util_queue_finish(&cache->cache_queue);
}
/* Return a filename within the cache's directory corresponding to 'key'. The
* returned filename is ralloced with 'cache' as the parent context.
*
* Returns NULL if out of memory.
*/
static char *
get_cache_file(struct disk_cache *cache, const cache_key key)
{
char buf[41];
char *filename;
if (cache->path_init_failed)
return NULL;
_mesa_sha1_format(buf, key);
if (asprintf(&filename, "%s/%c%c/%s", cache->path, buf[0],
buf[1], buf + 2) == -1)
return NULL;
return filename;
}
/* Create the directory that will be needed for the cache file for \key.
*
* Obviously, the implementation here must closely match
* _get_cache_file above.
*/
static void
make_cache_file_directory(struct disk_cache *cache, const cache_key key)
{
char *dir;
char buf[41];
_mesa_sha1_format(buf, key);
if (asprintf(&dir, "%s/%c%c", cache->path, buf[0], buf[1]) == -1)
return;
mkdir_if_needed(dir);
free(dir);
}
/* Given a directory path and predicate function, find the entry with
* the oldest access time in that directory for which the predicate
* returns true.
*
* 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_lru_file_matching(const char *dir_path,
bool (*predicate)(const char *dir_path,
const struct stat *,
const char *, const size_t))
{
DIR *dir;
struct dirent *entry;
char *filename;
char *lru_name = NULL;
time_t lru_atime = 0;
dir = opendir(dir_path);
if (dir == NULL)
return NULL;
while (1) {
entry = readdir(dir);
if (entry == NULL)
break;
struct stat sb;
if (fstatat(dirfd(dir), entry->d_name, &sb, 0) == 0) {
if (!lru_atime || (sb.st_atime < lru_atime)) {
size_t len = strlen(entry->d_name);
if (!predicate(dir_path, &sb, entry->d_name, len))
continue;
char *tmp = realloc(lru_name, len + 1);
if (tmp) {
lru_name = tmp;
memcpy(lru_name, entry->d_name, len + 1);
lru_atime = sb.st_atime;
}
}
}
}
if (lru_name == NULL) {
closedir(dir);
return NULL;
}
if (asprintf(&filename, "%s/%s", dir_path, lru_name) < 0)
filename = NULL;
free(lru_name);
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(const char *path, const struct stat *sb,
const char *d_name, const size_t len)
{
if (!S_ISREG(sb->st_mode))
return false;
if (len >= 4 && strcmp(&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_lru_file_from_directory(const char *path)
{
struct stat sb;
char *filename;
filename = choose_lru_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_blocks * 512;
}
/* Is entry a directory with a two-character name, (and not the
* special name of ".."). We also return false if the dir is empty.
*/
static bool
is_two_character_sub_directory(const char *path, const struct stat *sb,
const char *d_name, const size_t len)
{
if (!S_ISDIR(sb->st_mode))
return false;
if (len != 2)
return false;
if (strcmp(d_name, "..") == 0)
return false;
char *subdir;
if (asprintf(&subdir, "%s/%s", path, d_name) == -1)
return false;
DIR *dir = opendir(subdir);
free(subdir);
if (dir == NULL)
return false;
unsigned subdir_entries = 0;
struct dirent *d;
while ((d = readdir(dir)) != NULL) {
if(++subdir_entries > 2)
break;
}
closedir(dir);
/* If dir only contains '.' and '..' it must be empty */
if (subdir_entries <= 2)
return false;
return true;
}
static void
evict_lru_item(struct disk_cache *cache)
{
char *dir_path;
/* 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.
* Provides pseudo-LRU eviction to reduce checking all cache files.
*/
uint64_t rand64 = rand_xorshift128plus(cache->seed_xorshift128plus);
if (asprintf(&dir_path, "%s/%02" PRIx64 , cache->path, rand64 & 0xff) < 0)
return;
size_t size = unlink_lru_file_from_directory(dir_path);
free(dir_path);
if (size) {
p_atomic_add(cache->size, - (uint64_t)size);
return;
}
/* In the case where the random choice of directory didn't find
* something, we choose the least recently accessed 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_lru_file_matching(cache->path,
is_two_character_sub_directory);
if (dir_path == NULL)
return;
size = unlink_lru_file_from_directory(dir_path);
free(dir_path);
if (size)
p_atomic_add(cache->size, - (uint64_t)size);
}
void
disk_cache_remove(struct disk_cache *cache, const cache_key key)
{
struct stat sb;
char *filename = get_cache_file(cache, key);
if (filename == NULL) {
return;
}
if (stat(filename, &sb) == -1) {
free(filename);
return;
}
unlink(filename);
free(filename);
if (sb.st_blocks)
p_atomic_add(cache->size, - (uint64_t)sb.st_blocks * 512);
}
static ssize_t
read_all(int fd, void *buf, size_t count)
{
char *in = buf;
ssize_t read_ret;
size_t done;
for (done = 0; done < count; done += read_ret) {
read_ret = read(fd, in + done, count - done);
if (read_ret == -1 || read_ret == 0)
return -1;
}
return done;
}
static ssize_t
write_all(int fd, const void *buf, size_t count)
{
const char *out = buf;
ssize_t written;
size_t done;
for (done = 0; done < count; done += written) {
written = write(fd, out + done, count - done);
if (written == -1)
return -1;
}
return done;
}
/* From the zlib docs:
* "If the memory is available, buffers sizes on the order of 128K or 256K
* bytes should be used."
*/
#define BUFSIZE 256 * 1024
/**
* Compresses cache entry in memory and writes it to disk. Returns the size
* of the data written to disk.
*/
static size_t
deflate_and_write_to_disk(const void *in_data, size_t in_data_size, int dest,
const char *filename)
{
#ifdef HAVE_ZSTD
* compression runs faster if `dstCapacity` >= `ZSTD_compressBound(srcSize)`.
*/
size_t out_size = ZSTD_compressBound(in_data_size);
void * out = malloc(out_size);
size_t ret = ZSTD_compress(out, out_size, in_data, in_data_size,
ZSTD_COMPRESSION_LEVEL);
if (ZSTD_isError(ret)) {
free(out);
return 0;
}
ssize_t written = write_all(dest, out, ret);
if (written == -1) {
free(out);
return 0;
}
free(out);
return ret;
#else
unsigned char *out;
/* allocate deflate state */
z_stream strm;
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
strm.next_in = (uint8_t *) in_data;
strm.avail_in = in_data_size;
int ret = deflateInit(&strm, Z_BEST_COMPRESSION);
if (ret != Z_OK)
return 0;
/* compress until end of in_data */
size_t compressed_size = 0;
int flush;
out = malloc(BUFSIZE * sizeof(unsigned char));
if (out == NULL)
return 0;
do {
int remaining = in_data_size - BUFSIZE;
flush = remaining > 0 ? Z_NO_FLUSH : Z_FINISH;
in_data_size -= BUFSIZE;
/* Run deflate() on input until the output buffer is not full (which
* means there is no more data to deflate).
*/
do {
strm.avail_out = BUFSIZE;
strm.next_out = out;
ret = deflate(&strm, flush); /* no bad return value */
assert(ret != Z_STREAM_ERROR); /* state not clobbered */
size_t have = BUFSIZE - strm.avail_out;
compressed_size += have;
ssize_t written = write_all(dest, out, have);
if (written == -1) {
(void)deflateEnd(&strm);
free(out);
return 0;
}
} while (strm.avail_out == 0);
/* all input should be used */
assert(strm.avail_in == 0);
} while (flush != Z_FINISH);
/* stream should be complete */
assert(ret == Z_STREAM_END);
/* clean up and return */
(void)deflateEnd(&strm);
free(out);
return compressed_size;
# endif
}
static struct disk_cache_put_job *
create_put_job(struct disk_cache *cache, const cache_key key,
const void *data, size_t size,
struct cache_item_metadata *cache_item_metadata)
{
struct disk_cache_put_job *dc_job = (struct disk_cache_put_job *)
malloc(sizeof(struct disk_cache_put_job) + size);
if (dc_job) {
dc_job->cache = cache;
memcpy(dc_job->key, key, sizeof(cache_key));
dc_job->data = dc_job + 1;
memcpy(dc_job->data, data, size);
dc_job->size = size;
/* Copy the cache item metadata */
if (cache_item_metadata) {
dc_job->cache_item_metadata.type = cache_item_metadata->type;
if (cache_item_metadata->type == CACHE_ITEM_TYPE_GLSL) {
dc_job->cache_item_metadata.num_keys =
cache_item_metadata->num_keys;
dc_job->cache_item_metadata.keys = (cache_key *)
malloc(cache_item_metadata->num_keys * sizeof(cache_key));
if (!dc_job->cache_item_metadata.keys)
goto fail;
memcpy(dc_job->cache_item_metadata.keys,
cache_item_metadata->keys,
sizeof(cache_key) * cache_item_metadata->num_keys);
}
} else {
dc_job->cache_item_metadata.type = CACHE_ITEM_TYPE_UNKNOWN;
dc_job->cache_item_metadata.keys = NULL;
}
}
return dc_job;
fail:
free(dc_job);
return NULL;
}
static void
destroy_put_job(void *job, int thread_index)
{
if (job) {
struct disk_cache_put_job *dc_job = (struct disk_cache_put_job *) job;
free(dc_job->cache_item_metadata.keys);
free(job);
}
}
struct cache_entry_file_data {
uint32_t crc32;
uint32_t uncompressed_size;
};
static void
cache_put(void *job, int thread_index)
{
assert(job);
int fd = -1, fd_final = -1, err, ret;
unsigned i = 0;
char *filename = NULL, *filename_tmp = NULL;
struct disk_cache_put_job *dc_job = (struct disk_cache_put_job *) job;
filename = get_cache_file(dc_job->cache, dc_job->key);
if (filename == NULL)
goto done;
/* If the cache is too large, evict something else first. */
while (*dc_job->cache->size + dc_job->size > dc_job->cache->max_size &&
i < 8) {
evict_lru_item(dc_job->cache);
i++;
}
/* 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).
*/
if (asprintf(&filename_tmp, "%s.tmp", filename) == -1)
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(dc_job->cache, dc_job->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.
*/
#ifdef HAVE_FLOCK
err = flock(fd, LOCK_EX | LOCK_NB);
#else
struct flock lock = {
.l_start = 0,
.l_len = 0, /* entire file */
.l_type = F_WRLCK,
.l_whence = SEEK_SET
};
err = fcntl(fd, F_SETLK, &lock);
#endif
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) {
unlink(filename_tmp);
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.
*/
/* Write the driver_keys_blob, this can be used find information about the
* mesa version that produced the entry or deal with hash collisions,
* should that ever become a real problem.
*/
ret = write_all(fd, dc_job->cache->driver_keys_blob,
dc_job->cache->driver_keys_blob_size);
if (ret == -1) {
unlink(filename_tmp);
goto done;
}
/* Write the cache item metadata. This data can be used to deal with
* hash collisions, as well as providing useful information to 3rd party
* tools reading the cache files.
*/
ret = write_all(fd, &dc_job->cache_item_metadata.type,
sizeof(uint32_t));
if (ret == -1) {
unlink(filename_tmp);
goto done;
}
if (dc_job->cache_item_metadata.type == CACHE_ITEM_TYPE_GLSL) {
ret = write_all(fd, &dc_job->cache_item_metadata.num_keys,
sizeof(uint32_t));
if (ret == -1) {
unlink(filename_tmp);
goto done;
}
ret = write_all(fd, dc_job->cache_item_metadata.keys[0],
dc_job->cache_item_metadata.num_keys *
sizeof(cache_key));
if (ret == -1) {
unlink(filename_tmp);
goto done;
}
}
/* Create CRC of the data. We will read this when restoring the cache and
* use it to check for corruption.
*/
struct cache_entry_file_data cf_data;
cf_data.crc32 = util_hash_crc32(dc_job->data, dc_job->size);
cf_data.uncompressed_size = dc_job->size;
size_t cf_data_size = sizeof(cf_data);
ret = write_all(fd, &cf_data, cf_data_size);
if (ret == -1) {
unlink(filename_tmp);
goto done;
}
/* 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.
*/
size_t file_size = deflate_and_write_to_disk(dc_job->data, dc_job->size,
fd, filename_tmp);
if (file_size == 0) {
unlink(filename_tmp);
goto done;
}
ret = rename(filename_tmp, filename);
if (ret == -1) {
unlink(filename_tmp);
goto done;
}
struct stat sb;
if (stat(filename, &sb) == -1) {
/* Something went wrong remove the file */
unlink(filename);
goto done;
}
p_atomic_add(dc_job->cache->size, sb.st_blocks * 512);
done:
if (fd_final != -1)
close(fd_final);
/* This close finally releases the flock, (now that the final file
* has been renamed into place and the size has been added).
*/
if (fd != -1)
close(fd);
free(filename_tmp);
free(filename);
}
void
disk_cache_put(struct disk_cache *cache, const cache_key key,
const void *data, size_t size,
struct cache_item_metadata *cache_item_metadata)
{
if (cache->blob_put_cb) {
cache->blob_put_cb(key, CACHE_KEY_SIZE, data, size);
return;
}
if (cache->path_init_failed)
return;
struct disk_cache_put_job *dc_job =
create_put_job(cache, key, data, size, cache_item_metadata);
if (dc_job) {
util_queue_fence_init(&dc_job->fence);
util_queue_add_job(&cache->cache_queue, dc_job, &dc_job->fence,
cache_put, destroy_put_job, dc_job->size);
}
}
/**
* Decompresses cache entry, returns true if successful.
*/
static bool
inflate_cache_data(uint8_t *in_data, size_t in_data_size,
uint8_t *out_data, size_t out_data_size)
{
#ifdef HAVE_ZSTD
size_t ret = ZSTD_decompress(out_data, out_data_size, in_data, in_data_size);
return !ZSTD_isError(ret);
#else
z_stream strm;
/* allocate inflate state */
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
strm.next_in = in_data;
strm.avail_in = in_data_size;
strm.next_out = out_data;
strm.avail_out = out_data_size;
int ret = inflateInit(&strm);
if (ret != Z_OK)
return false;
ret = inflate(&strm, Z_NO_FLUSH);
assert(ret != Z_STREAM_ERROR); /* state not clobbered */
/* Unless there was an error we should have decompressed everything in one
* go as we know the uncompressed file size.
*/
if (ret != Z_STREAM_END) {
(void)inflateEnd(&strm);
return false;
}
assert(strm.avail_out == 0);
/* clean up and return */
(void)inflateEnd(&strm);
return true;
#endif
}
void *
disk_cache_get(struct disk_cache *cache, const cache_key key, size_t *size)
{
int fd = -1, ret;
struct stat sb;
char *filename = NULL;
uint8_t *data = NULL;
uint8_t *uncompressed_data = NULL;
uint8_t *file_header = NULL;
if (size)
*size = 0;
if (cache->blob_get_cb) {
/* This is what Android EGL defines as the maxValueSize in egl_cache_t
* class implementation.
*/
const signed long max_blob_size = 64 * 1024;
void *blob = malloc(max_blob_size);
if (!blob)
return NULL;
signed long bytes =
cache->blob_get_cb(key, CACHE_KEY_SIZE, blob, max_blob_size);
if (!bytes) {
free(blob);
return NULL;
}
if (size)
*size = bytes;
return blob;
}
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;
size_t ck_size = cache->driver_keys_blob_size;
file_header = malloc(ck_size);
if (!file_header)
goto fail;
if (sb.st_size < ck_size)
goto fail;
ret = read_all(fd, file_header, ck_size);
if (ret == -1)
goto fail;
/* Check for extremely unlikely hash collisions */
if (memcmp(cache->driver_keys_blob, file_header, ck_size) != 0) {
assert(!"Mesa cache keys mismatch!");
goto fail;
}
size_t cache_item_md_size = sizeof(uint32_t);
uint32_t md_type;
ret = read_all(fd, &md_type, cache_item_md_size);
if (ret == -1)
goto fail;
if (md_type == CACHE_ITEM_TYPE_GLSL) {
uint32_t num_keys;
cache_item_md_size += sizeof(uint32_t);
ret = read_all(fd, &num_keys, sizeof(uint32_t));
if (ret == -1)
goto fail;
/* The cache item metadata is currently just used for distributing
* precompiled shaders, they are not used by Mesa so just skip them for
* now.
* TODO: pass the metadata back to the caller and do some basic
* validation.
*/
cache_item_md_size += num_keys * sizeof(cache_key);
ret = lseek(fd, num_keys * sizeof(cache_key), SEEK_CUR);
if (ret == -1)
goto fail;
}
/* Load the CRC that was created when the file was written. */
struct cache_entry_file_data cf_data;
size_t cf_data_size = sizeof(cf_data);
ret = read_all(fd, &cf_data, cf_data_size);
if (ret == -1)
goto fail;
/* Load the actual cache data. */
size_t cache_data_size =
sb.st_size - cf_data_size - ck_size - cache_item_md_size;
ret = read_all(fd, data, cache_data_size);
if (ret == -1)
goto fail;
/* Uncompress the cache data */
uncompressed_data = malloc(cf_data.uncompressed_size);
if (!inflate_cache_data(data, cache_data_size, uncompressed_data,
cf_data.uncompressed_size))
goto fail;
/* Check the data for corruption */
if (cf_data.crc32 != util_hash_crc32(uncompressed_data,
cf_data.uncompressed_size))
goto fail;
free(data);
free(filename);
free(file_header);
close(fd);
if (size)
*size = cf_data.uncompressed_size;
return uncompressed_data;
fail:
if (data)
free(data);
if (uncompressed_data)
free(uncompressed_data);
if (filename)
free(filename);
if (file_header)
free(file_header);
if (fd != -1)
close(fd);
return NULL;
}
void
disk_cache_put_key(struct disk_cache *cache, const cache_key key)
{
const uint32_t *key_chunk = (const uint32_t *) key;
int i = CPU_TO_LE32(*key_chunk) & CACHE_INDEX_KEY_MASK;
unsigned char *entry;
if (cache->blob_put_cb) {
cache->blob_put_cb(key, CACHE_KEY_SIZE, key_chunk, sizeof(uint32_t));
return;
}
if (cache->path_init_failed)
return;
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 disk_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 disk_cache_put_key, then that's just an extra cache miss and an
* extra recompile.
*/
bool
disk_cache_has_key(struct disk_cache *cache, const cache_key key)
{
const uint32_t *key_chunk = (const uint32_t *) key;
int i = CPU_TO_LE32(*key_chunk) & CACHE_INDEX_KEY_MASK;
unsigned char *entry;
if (cache->blob_get_cb) {
uint32_t blob;
return cache->blob_get_cb(key, CACHE_KEY_SIZE, &blob, sizeof(uint32_t));
}
if (cache->path_init_failed)
return false;
entry = &cache->stored_keys[i * CACHE_KEY_SIZE];
return memcmp(entry, key, CACHE_KEY_SIZE) == 0;
}
void
disk_cache_compute_key(struct disk_cache *cache, const void *data, size_t size,
cache_key key)
{
struct mesa_sha1 ctx;
_mesa_sha1_init(&ctx);
_mesa_sha1_update(&ctx, cache->driver_keys_blob,
cache->driver_keys_blob_size);
_mesa_sha1_update(&ctx, data, size);
_mesa_sha1_final(&ctx, key);
}
void
disk_cache_set_callbacks(struct disk_cache *cache, disk_cache_put_cb put,
disk_cache_get_cb get)
{
cache->blob_put_cb = put;
cache->blob_get_cb = get;
}
#endif /* ENABLE_SHADER_CACHE */