[Mesa-dev] [PATCH v2 5/5] util/disk_cache: write cache item metadata to disk

[Timothy Arceri]

---
 src/util/disk_cache.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 88 insertions(+), 1 deletion(-)

diff --git a/src/util/disk_cache.c b/src/util/disk_cache.c
index c1b7429b92..dd12a09841 100644
--- a/src/util/disk_cache.c
+++ b/src/util/disk_cache.c
@@ -105,20 +105,22 @@ struct disk_cache_put_job {
 
    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)
 {
@@ -771,29 +773,60 @@ create_put_job(struct disk_cache *cache, const cache_key key,
 {
    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;
+
+            for (unsigned i = 0; i < cache_item_metadata->num_keys; i++) {
+               memcpy(dc_job->cache_item_metadata.keys[i],
+                      cache_item_metadata->keys[i], sizeof(cache_key));
+            }
+         }
+      } 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->cache_item_metadata.keys);
+   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
@@ -868,20 +901,48 @@ cache_put(void *job, int thread_index)
     * 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) {
@@ -1019,29 +1080,55 @@ disk_cache_get(struct disk_cache *cache, const cache_key key, size_t *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)
       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 += 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;
+   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;
 
-- 
2.13.4