Add SkCachedData and use it for SkMipMap

tests/SkResourceCacheTest.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Test.h"
 #include "SkBitmapCache.h"
 #include "SkCanvas.h"
@@ skipping 103 matching lines @@
     REPORTER_ASSERT(reporter, !SkBitmapCache::Find(cachedBitmap.getGenerationID(), rect, &bm, cache));
 
     // Should not be in the cache
     REPORTER_ASSERT(reporter, !SkBitmapCache::Find(cachedBitmap.getGenerationID(), rect, &bm, cache));
 
     REPORTER_ASSERT(reporter, SkBitmapCache::Add(cachedBitmap.getGenerationID(), rect, cachedBitmap, cache));
     // Should be in the cache, we just added it
     REPORTER_ASSERT(reporter, SkBitmapCache::Find(cachedBitmap.getGenerationID(), rect, &bm, cache));
 }
 
+#include "SkMipMap.h"
+
+enum LockedState {
+    kNotLocked,
+    kLocked,
+};
+
+enum CachedState {
+    kNotInCache,
+    kInCache,
+};
+
+static void check_data(skiatest::Reporter* reporter, const SkCachedData* data,
+                       int refcnt, CachedState cacheState, LockedState lockedState) {
+    REPORTER_ASSERT(reporter, data->testing_only_getRefCnt() == refcnt);
+    REPORTER_ASSERT(reporter, data->testing_only_isInCache() == (kInCache == cacheState));
+    bool isLocked = (data->data() != NULL);
+    REPORTER_ASSERT(reporter, isLocked == (lockedState == kLocked));
+}
+
+static void test_mipmapcache(skiatest::Reporter* reporter, SkResourceCache* cache) {
+    cache->purgeAll();
+
+    SkBitmap src;
+    src.allocN32Pixels(5, 5);
+    src.setImmutable();
+
+    const SkMipMap* mipmap = SkMipMapCache::FindAndRef(src, cache);
+    REPORTER_ASSERT(reporter, NULL == mipmap);
+
+    mipmap = SkMipMapCache::AddAndRef(src, cache);
+    REPORTER_ASSERT(reporter, mipmap);
+    check_data(reporter, mipmap, 2, kInCache, kLocked);
+
+    mipmap->unref();
+    // tricky, since technically after this I'm no longer an owner, but since the cache is
+    // local, I know it won't get purged behind my back
+    check_data(reporter, mipmap, 1, kInCache, kNotLocked);
+
+    // find us again
+    mipmap = SkMipMapCache::FindAndRef(src, cache);
+    check_data(reporter, mipmap, 2, kInCache, kLocked);
+
+    cache->purgeAll();
+    check_data(reporter, mipmap, 1, kNotInCache, kLocked);
+
+    mipmap->unref();
+}
+
 DEF_TEST(BitmapCache_discarded_bitmap, reporter) {
     SkResourceCache::DiscardableFactory factory = SkResourceCache::GetDiscardableFactory();
     SkBitmap::Allocator* allocator = SkBitmapCache::GetAllocator();
     
     SkAutoTDelete<SkResourceCache> cache;
     if (factory) {
         cache.reset(SkNEW_ARGS(SkResourceCache, (factory)));
     } else {
         const size_t byteLimit = 100 * 1024;
         cache.reset(SkNEW_ARGS(SkResourceCache, (byteLimit)));
@@ skipping 24 matching lines @@
         REPORTER_ASSERT(reporter, !SkBitmapCache::Find(cachedBitmap.getGenerationID(), rect, &bm, cache));
     }
 
     make_bitmap(&cachedBitmap, SkImageInfo::MakeN32Premul(5, 5), allocator);
     cachedBitmap.setImmutable();
     cachedBitmap.unlockPixels();
 
     // We can add the bitmap back to the cache and find it again.
     REPORTER_ASSERT(reporter, SkBitmapCache::Add(cachedBitmap.getGenerationID(), rect, cachedBitmap, cache));
     REPORTER_ASSERT(reporter, SkBitmapCache::Find(cachedBitmap.getGenerationID(), rect, &bm, cache));
+
+    test_mipmapcache(reporter, cache);
 }