GrResourceCache2 manages scratch texture.

include/gpu/GrGpuResource.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGpuResource_DEFINED
 #define GrGpuResource_DEFINED
 
@@ skipping 31 matching lines @@
         kWrite_IOType,
         kRW_IOType
     };
 
     virtual ~GrIORef();
 
     // Some of the signatures are written to mirror SkRefCnt so that GrGpuResource can work with
     // templated helper classes (e.g. SkAutoTUnref). However, we have different categories of
     // refs (e.g. pending reads). We also don't require thread safety as GrCacheable objects are
     // not intended to cross thread boundaries.
-    // internal_dispose() exists because of GrTexture's reliance on it. It will be removed
-    // soon.
     void ref() const {
+        this->validate();
         ++fRefCnt;
-        // pre-validate once internal_dispose is removed (and therefore 0 ref cnt is not allowed).
-        this->validate();
     }
 
     void unref() const {
         this->validate();
         --fRefCnt;
         if (0 == fRefCnt && 0 == fPendingReads && 0 == fPendingWrites) {
-            this->internal_dispose();
+            SkDELETE(this);
         }
     }
 
-    virtual void internal_dispose() const { SkDELETE(this); }
-
-    /** This is exists to service the old mechanism for recycling scratch textures. It will
-        be removed soon. */
-    bool unique() const { return 1 == (fRefCnt + fPendingReads + fPendingWrites); }
+    bool isPurgable() const { return this->reffedOnlyByCache() && !this->internalHasPendingIO(); }
+    bool reffedOnlyByCache() const { return 1 == fRefCnt; }
 
     void validate() const {
 #ifdef SK_DEBUG
         SkASSERT(fRefCnt >= 0);
         SkASSERT(fPendingReads >= 0);
         SkASSERT(fPendingWrites >= 0);
         SkASSERT(fRefCnt + fPendingReads + fPendingWrites > 0);
 #endif
     }
 
-
 protected:
-    GrIORef() : fRefCnt(1), fPendingReads(0), fPendingWrites(0) {}
+    GrIORef() : fRefCnt(1), fPendingReads(0), fPendingWrites(0), fIsScratch(kNo_IsScratch) { }
 
     bool internalHasPendingRead() const { return SkToBool(fPendingReads); }
     bool internalHasPendingWrite() const { return SkToBool(fPendingWrites); }
     bool internalHasPendingIO() const { return SkToBool(fPendingWrites | fPendingReads); }
 
 private:
     void addPendingRead() const {
         this->validate();
         ++fPendingReads;
     }
 
     void completedRead() const {
         this->validate();
         --fPendingReads;
         if (0 == fRefCnt && 0 == fPendingReads && 0 == fPendingWrites) {
-            this->internal_dispose();
+            SkDELETE(this);
         }
     }
 
     void addPendingWrite() const {
         this->validate();
         ++fPendingWrites;
     }
 
     void completedWrite() const {
         this->validate();
         --fPendingWrites;
         if (0 == fRefCnt && 0 == fPendingReads && 0 == fPendingWrites) {
-            this->internal_dispose();
+            SkDELETE(this);
         }
     }
 
 private:
     mutable int32_t fRefCnt;
     mutable int32_t fPendingReads;
     mutable int32_t fPendingWrites;
 
     // This class is used to manage conversion of refs to pending reads/writes.
     friend class GrGpuResourceRef;
+
+    // This is temporary until GrResourceCache is fully replaced by GrResourceCache2.
+    enum IsScratch {
+        kNo_IsScratch,
+        kYes_IsScratch
+    } fIsScratch;
+
+    friend class GrContext; // to set the above field.
+    friend class GrResourceCache; // to check the above field.
+    friend class GrResourceCache2; // to check the above field.
+
     template <typename, IOType> friend class GrPendingIOResource;
 };
 
 /**
  * Base class for objects that can be kept in the GrResourceCache.
  */
 class GrGpuResource : public GrIORef {
 public:
     SK_DECLARE_INST_COUNT(GrGpuResource)
 
@@ skipping 115 matching lines @@
 
     GrResourceCacheEntry*   fCacheEntry;  // NULL if not in cache
     const uint32_t          fUniqueID;
 
     GrResourceKey           fScratchKey;
 
     typedef GrIORef INHERITED;
 };
 
 #endif