Random eviction

src/cache.c

@@ -32,7 +32,6 @@ size_t git_cache__max_object_size = 4096;
 
 int git_cache_init(git_cache *cache)
 {
-	cache->lru_count = 0;
 	cache->map = git_oidmap_alloc();
 	git_mutex_init(&cache->lock);
 	return 0;
@@ -44,6 +43,24 @@ void git_cache_free(git_cache *cache)
 	git_mutex_free(&cache->lock);
 }
 
+static void cache_evict_entries(git_cache *cache, size_t evict)
+{
+	uint32_t seed = rand();
+
+	/* do not infinite loop if there's not enough entries to evict  */
+	if (evict > kh_size(cache->map))
+		return;
+
+	while (evict > 0) {
+		khiter_t pos = seed++ % kh_end(cache->map);
+
+		if (kh_exist(cache->map, pos)) {
+			kh_del(oid, cache->map, pos);
+			evict--;
+		}
+	}
+}
+
 static bool cache_should_store(git_otype object_type, size_t object_size)
 {
 	if (!git_cache__store_types[object_type])

src/cache.h

@@ -23,14 +23,13 @@ enum {
 typedef struct {
 	git_oid oid;
 	git_atomic refcount;
-	uint16_t flags;
-	uint16_t lru;
+	uint32_t cache_size;
+	uint32_t flags;
 } git_cached_obj;
 
 typedef struct {
 	git_oidmap *map;
 	git_mutex lock;
-	unsigned int lru_count;
 } git_cache;
 
 int git_cache_init(git_cache *cache);

src/object.c

@@ -98,6 +98,7 @@ int git_object__from_odb_object(
 
 	/* Initialize parent object */
 	git_oid_cpy(&object->cached.oid, &odb_obj->cached.oid);
+	object->cached.cache_size = (uint32_t)odb_obj->raw.len;
 	object->repo = repo;
 
 	switch (type) {