[Mesa-dev] [PATCH 5/7] util/disk_cache: hash pointer size and gpu name into cache keys

[Timothy Arceri]

On 16/03/17 10:09, Grazvydas Ignotas wrote:
> This allows to get rid of the arch and gpu name directories.
> Also, gpu_name is now optional.
>
> Signed-off-by: Grazvydas Ignotas <notasas at gmail.com>
> ---
>  src/compiler/glsl/tests/cache_test.c | 13 ++--------
>  src/util/disk_cache.c                | 47 +++++++++++++++---------------------
>  src/util/disk_cache.h                | 17 -------------
>  3 files changed, 21 insertions(+), 56 deletions(-)
>
> diff --git a/src/compiler/glsl/tests/cache_test.c b/src/compiler/glsl/tests/cache_test.c
> index f923e8d..f6d3621 100644
> --- a/src/compiler/glsl/tests/cache_test.c
> +++ b/src/compiler/glsl/tests/cache_test.c
> @@ -182,16 +182,11 @@ test_disk_cache_create(void)
>     expect_null(cache, "disk_cache_create with XDG_CACHE_HOME set with"
>                 "a non-existing parent directory");
>
> -   /* Create string with expected directory hierarchy */
> -   char expected_dir_h[255];
> -   sprintf(expected_dir_h, "%s%s%s", CACHE_TEST_TMP "/xdg-cache-home/mesa/",
> -           get_arch_bitness_str(), "/test");
> -
>     mkdir(CACHE_TEST_TMP, 0755);
>     cache = disk_cache_create("test", version_blob, sizeof(version_blob));
>     expect_non_null(cache, "disk_cache_create with XDG_CACHE_HOME set");
>
> -   check_directories_created(expected_dir_h);
> +   check_directories_created(CACHE_TEST_TMP "/xdg-cache-home/mesa");
>
>     disk_cache_destroy(cache);
>
> @@ -204,15 +199,11 @@ test_disk_cache_create(void)
>     expect_null(cache, "disk_cache_create with MESA_GLSL_CACHE_DIR set with"
>                 "a non-existing parent directory");
>
> -   sprintf(expected_dir_h, "%s%s%s", CACHE_TEST_TMP
> -           "/mesa-glsl-cache-dir/mesa/", get_arch_bitness_str(),
> -           "/test");
> -
>     mkdir(CACHE_TEST_TMP, 0755);
>     cache = disk_cache_create("test", version_blob, sizeof(version_blob));
>     expect_non_null(cache, "disk_cache_create with MESA_GLSL_CACHE_DIR set");
>
> -   check_directories_created(expected_dir_h);
> +   check_directories_created(CACHE_TEST_TMP "/mesa-glsl-cache-dir/mesa");
>
>     disk_cache_destroy(cache);
>  }
> diff --git a/src/util/disk_cache.c b/src/util/disk_cache.c
> index 5b249d9..904aa66 100644
> --- a/src/util/disk_cache.c
> +++ b/src/util/disk_cache.c
> @@ -158,29 +158,6 @@ concatenate_and_mkdir(void *ctx, const char *path, const char *name)
>        return NULL;
>  }
>
> -static char *
> -create_mesa_cache_dir(void *mem_ctx, const char *path, const char *gpu_name)
> -{
> -   char *new_path = concatenate_and_mkdir(mem_ctx, path, "mesa");
> -   if (new_path == NULL)
> -      return NULL;
> -
> -   /* Create a parent architecture directory so that we don't remove cache
> -    * files for other architectures. In theory we could share the cache
> -    * between architectures but we have no way of knowing if they were created
> -    * by a compatible Mesa version.
> -    */
> -   new_path = concatenate_and_mkdir(mem_ctx, new_path, get_arch_bitness_str());
> -   if (new_path == NULL)
> -      return NULL;
> -
> -   new_path = concatenate_and_mkdir(mem_ctx, new_path, gpu_name);
> -   if (new_path == NULL)
> -      return NULL;
> -
> -   return new_path;
> -}
> -
>  struct disk_cache *
>  disk_cache_create(const char *gpu_name, const void *version_blob,
>                    size_t version_blob_size)
> @@ -218,7 +195,7 @@ disk_cache_create(const char *gpu_name, const void *version_blob,
>        if (mkdir_if_needed(path) == -1)
>           goto fail;
>
> -      path = create_mesa_cache_dir(local, path, gpu_name);
> +      path = concatenate_and_mkdir(local, path, "mesa");
>        if (path == NULL)
>           goto fail;
>     }
> @@ -230,7 +207,7 @@ disk_cache_create(const char *gpu_name, const void *version_blob,
>           if (mkdir_if_needed(xdg_cache_home) == -1)
>              goto fail;
>
> -         path = create_mesa_cache_dir(local, xdg_cache_home, gpu_name);
> +         path = concatenate_and_mkdir(local, xdg_cache_home, "mesa");
>           if (path == NULL)
>              goto fail;
>        }
> @@ -266,7 +243,7 @@ disk_cache_create(const char *gpu_name, const void *version_blob,
>        if (path == NULL)
>           goto fail;
>
> -      path = create_mesa_cache_dir(local, path, gpu_name);
> +      path = concatenate_and_mkdir(local, path, "mesa");
>        if (path == NULL)
>           goto fail;
>     }
> @@ -275,11 +252,25 @@ disk_cache_create(const char *gpu_name, const void *version_blob,
>     if (cache == NULL)
>        goto fail;
>
> -   cache->key_blob_size = version_blob_size;
> +   /* Prepare the blob to hash into the cache keys */
> +   uint8_t pointer_size = sizeof(void *);
> +   cache->key_blob_size = version_blob_size + sizeof(pointer_size);
> +   if (gpu_name != NULL)
> +      cache->key_blob_size += strlen(gpu_name);
>     cache->key_blob = ralloc_size(cache, cache->key_blob_size);
>     if (cache->key_blob == NULL)
>        goto fail;
> -   memcpy(cache->key_blob, version_blob, version_blob_size);
> +
> +   char *pos = cache->key_blob;
> +   memcpy(pos, version_blob, version_blob_size);
> +   pos += version_blob_size;
> +   memcpy(pos, &pointer_size, sizeof(pointer_size));
> +   pos += sizeof(pointer_size);
> +   if (gpu_name != NULL) {

Is there any valid reason for this to be NULL? Can we just add an 
assert() and assume this is never NULL?