[Mesa-dev] [PATCH 2/4] util/disk_cache: add struct cache_item_metadata

[Timothy Arceri]

This will be used to store more information about the cache item
in it's header. This information is intended for 3rd party and
cache analysis use but can also be used for detecting the unlikely
scenario of cache collisions.
---
 src/util/disk_cache.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/util/disk_cache.h b/src/util/disk_cache.h
index 9aade16a9e..d6d7609ffb 100644
--- a/src/util/disk_cache.h
+++ b/src/util/disk_cache.h
@@ -34,20 +34,42 @@
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 /* Size of cache keys in bytes. */
 #define CACHE_KEY_SIZE 20
 
 typedef uint8_t cache_key[CACHE_KEY_SIZE];
 
+/* WARNING: 3rd party applications might be reading the cache item metadata.
+ * Do not change these values without making the change widely known.
+ * Please contact Valve developers and make them aware of this change.
+ */
+#define CACHE_ITEM_TYPE_UNKNOWN  0x0
+#define CACHE_ITEM_TYPE_GLSL     0x1
+
+typedef uint32_t cache_item_metadata_type;
+
+struct cache_item_metadata {
+   /**
+    * The cache item type. This could be used to identify a GLSL cache item,
+    * a certain type of IR (tgsi, nir, etc), or signal that it is the final
+    * binary form of the shader.
+    */
+   cache_item_metadata_type type;
+
+   /** GLSL cache item metadata */
+   cache_key *keys;   /* sha1 list of shaders that make up the cache item */
+   uint32_t num_keys;
+};
+
 struct disk_cache;
 
 static inline bool
 disk_cache_get_function_timestamp(void *ptr, uint32_t* timestamp)
 {
 #ifdef ENABLE_SHADER_CACHE
    Dl_info info;
    struct stat st;
    if (!dladdr(ptr, &info) || !info.dli_fname) {
       return false;
-- 
2.13.4