This can be used to deal with key hash collisions from different
versions (should we find that to actually happen) and to find
which mesa version produced the cache entry.
---
I considered creating the cache key blob at cache creation time but since
we would want a blob with the null terminator dropped for the hash and one
that includes the terminator for reading the strings from the header, I
decided just to create it on the fly to keep the code easier to follow.
src/util/disk_cache.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 85 insertions(+), 6 deletions(-)
diff --git a/src/util/disk_cache.c b/src/util/disk_cache.c
index 599e58f..f2d67c9 100644
--- a/src/util/disk_cache.c
+++ b/src/util/disk_cache.c
@@ -737,33 +737,60 @@ create_put_job(struct disk_cache *cache, const cache_key
key,
}
static void
destroy_put_job(void *job, int thread_index)
{
if (job) {
free(job);
}
}
+static size_t
+cache_keys_size(struct disk_cache *cache)
+{
+ /* The 2 is for the terminating null bytes of the strings */
+ return cache->timestamp_size + cache->gpu_name_size +
+ sizeof(cache->ptr_size) + 2;
+}
+
+static uint8_t *
+generate_cache_keys_blob(struct disk_cache *cache, size_t ck_size)
+{
+ uint8_t *key_blob = malloc(ck_size);
+ if (!key_blob)
+ return NULL;
+
+ size_t ts_size = cache->timestamp_size + 1;
+ memcpy(key_blob, cache->timestamp, ts_size);
+
+ size_t gn_size = cache->gpu_name_size + 1;
+ memcpy(key_blob + ts_size, cache->gpu_name, gn_size);
+
+ memcpy(key_blob + ts_size + gn_size, &cache->ptr_size, sizeof(uint8_t));
+
+ return key_blob;
+}
+
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;
+ uint8_t *key_blob = 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);
@@ -808,23 +835,41 @@ cache_put(void *job, int thread_index)
*/
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.
- *
- * Create CRC of the data and store at the start of the file. We will
- * read this when restoring the cache and use it to check for corruption.
+ */
+
+ /* Write the key_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.
+ */
+ size_t ck_size = cache_keys_size(dc_job->cache);
+ key_blob = generate_cache_keys_blob(dc_job->cache, ck_size);
+ if (!key_blob) {
+ unlink(filename_tmp);
+ goto done;
+ }
+
+ ret = write_all(fd, key_blob, ck_size);
+ 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;
@@ -839,35 +884,37 @@ cache_put(void *job, int thread_index)
if (file_size == 0) {
unlink(filename_tmp);
goto done;
}
ret = rename(filename_tmp, filename);
if (ret == -1) {
unlink(filename_tmp);
goto done;
}
- file_size += cf_data_size;
+ file_size += cf_data_size + ck_size;
p_atomic_add(dc_job->cache->size, file_size);
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);
if (filename_tmp)
free(filename_tmp);
if (filename)
free(filename);
+ if (key_blob)
+ free(key_blob);
}
void
disk_cache_put(struct disk_cache *cache, const cache_key key,
const void *data, size_t size)
{
struct disk_cache_put_job *dc_job =
create_put_job(cache, key, data, size);
if (dc_job) {
@@ -936,32 +983,64 @@ disk_cache_get(struct disk_cache *cache, const cache_key
key, size_t *size)
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_keys_size(cache);
+#ifndef NDEBUG
+ uint8_t *file_header = malloc(ck_size);
+ if (!file_header)
+ goto fail;
+
+ assert(sb.st_size > ck_size);
+ for (len = 0; len < ck_size; len += ret) {
+ ret = read(fd, ((uint8_t *) file_header) + len, ck_size - len);
+ if (ret == -1) {
+ free(file_header);
+ goto fail;
+ }
+ }
+
+ uint8_t *key_blob = generate_cache_keys_blob(cache, ck_size);
+ if (!key_blob) {
+ free(file_header);
+ goto fail;
+ }
+ assert(memcmp(key_blob, file_header, ck_size) == 0);
+
+ free(file_header);
+ free(key_blob);
+#else
+ /* The cache keys are currently just used for distributing precompiled
+ * shaders, they are not used by Mesa so just skip them for now.
+ */
+ ret = lseek(fd, ck_size, SEEK_CUR);
+ if (ret == -1)
+ goto fail;
+#endif
+
/* 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);
- assert(sb.st_size > cf_data_size);
for (len = 0; len < cf_data_size; len += ret) {
ret = read(fd, ((uint8_t *) &cf_data) + len, cf_data_size - len);
if (ret == -1)
goto fail;
}
/* Load the actual cache data. */
- size_t cache_data_size = sb.st_size - cf_data_size;
+ size_t cache_data_size = sb.st_size - cf_data_size - ck_size;
for (len = 0; len < cache_data_size; len += ret) {
ret = read(fd, data + len, cache_data_size - len);
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))
--
2.9.3
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