1 files changed, 251 insertions, 0 deletions
diff --git a/src/gpu/GrResourceCache.h b/src/gpu/GrResourceCache.h
new file mode 100644
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+++ b/src/gpu/GrResourceCache.h
@@ -0,0 +1,251 @@
+
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrResourceCache_DEFINED
+#define GrResourceCache_DEFINED
+
+#include "GrDrawTargetCaps.h"
+#include "GrResourceKey.h"
+#include "SkTMultiMap.h"
+#include "SkMessageBus.h"
+#include "SkTInternalLList.h"
+
+class GrGpuResource;
+class GrResourceCache;
+class GrResourceCacheEntry;
+
+
+// The cache listens for these messages to purge junk resources proactively.
+struct GrResourceInvalidatedMessage {
+    GrResourceKey key;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+class GrResourceCacheEntry {
+public:
+    GrGpuResource* resource() const { return fResource; }
+
+    static uint32_t Hash(const GrGpuResource* resource) {
+        return static_cast<uint32_t>(reinterpret_cast<intptr_t>(resource));
+    }
+#ifdef SK_DEBUG
+    void validate() const;
+#else
+    void validate() const {}
+#endif
+
+    /**
+     *  Update the cached size for this entry and inform the resource cache that
+     *  it has changed. Usually invoked from GrGpuResource::didChangeGpuMemorySize,
+     *  not directly from here.
+     */
+    void didChangeResourceSize();
+
+private:
+    GrResourceCacheEntry(GrResourceCache*, GrGpuResource*);
+    ~GrResourceCacheEntry();
+
+    GrResourceCache* fResourceCache;
+    GrGpuResource*   fResource;
+    size_t           fCachedSize;
+
+    // Linked list for the LRU ordering.
+    SK_DECLARE_INTERNAL_LLIST_INTERFACE(GrResourceCacheEntry);
+
+    friend class GrResourceCache;
+    friend class GrContext;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+/**
+ *  Cache of GrGpuResource objects.
+ *
+ *  These have a corresponding GrResourceKey, built from 128bits identifying the
+ *  resource. Multiple resources can map to same GrResourceKey.
+ *
+ *  The cache stores the entries in a double-linked list, which is its LRU.
+ *  When an entry is "locked" (i.e. given to the caller), it is moved to the
+ *  head of the list. If/when we must purge some of the entries, we walk the
+ *  list backwards from the tail, since those are the least recently used.
+ *
+ *  For fast searches, we maintain a hash map based on the GrResourceKey.
+ *
+ *  It is a goal to make the GrResourceCache the central repository and bookkeeper
+ *  of all resources. It should replace the linked list of GrGpuResources that
+ *  GrGpu uses to call abandon/release.
+ */
+class GrResourceCache {
+public:
+    GrResourceCache(const GrDrawTargetCaps*, int maxCount, size_t maxBytes);
+    ~GrResourceCache();
+
+    /**
+     *  Return the current resource cache limits.
+     *
+     *  @param maxResource If non-null, returns maximum number of resources
+     *                     that can be held in the cache.
+     *  @param maxBytes    If non-null, returns maximum number of bytes of
+     *                     gpu memory that can be held in the cache.
+     */
+    void getLimits(int* maxResources, size_t* maxBytes) const;
+
+    /**
+     *  Specify the resource cache limits. If the current cache exceeds either
+     *  of these, it will be purged (LRU) to keep the cache within these limits.
+     *
+     *  @param maxResources The maximum number of resources that can be held in
+     *                      the cache.
+     *  @param maxBytes     The maximum number of bytes of resource memory that
+     *                      can be held in the cache.
+     */
+    void setLimits(int maxResources, size_t maxResourceBytes);
+
+    /**
+     *  The callback function used by the cache when it is still over budget
+     *  after a purge. The passed in 'data' is the same 'data' handed to
+     *  setOverbudgetCallback. The callback returns true if some resources
+     *  have been freed.
+     */
+    typedef bool (*PFOverbudgetCB)(void* data);
+
+    /**
+     *  Set the callback the cache should use when it is still over budget
+     *  after a purge. The 'data' provided here will be passed back to the
+     *  callback. Note that the cache will attempt to purge any resources newly
+     *  freed by the callback.
+     */
+    void setOverbudgetCallback(PFOverbudgetCB overbudgetCB, void* data) {
+        fOverbudgetCB = overbudgetCB;
+        fOverbudgetData = data;
+    }
+
+    /**
+     * Returns the number of bytes consumed by cached resources.
+     */
+    size_t getCachedResourceBytes() const { return fEntryBytes; }
+
+    /**
+     * Returns the number of cached resources.
+     */
+    int getCachedResourceCount() const { return fEntryCount; }
+
+    void makeResourceMRU(GrGpuResource*);
+
+    /** Called by GrGpuResources when they detects that they are newly purgable. */
+    void notifyPurgable(const GrGpuResource*);
+
+    /**
+     *  Add the new resource to the cache (by creating a new cache entry based
+     *  on the provided key and resource).
+     *
+     *  Ownership of the resource is transferred to the resource cache,
+     *  which will unref() it when it is purged or deleted.
+     *
+     *  This can fail if the key is already taken, or the resource is already in
+     *  the cache.
+     */
+    bool addResource(const GrResourceKey& key, GrGpuResource* resource);
+
+    /**
+     * Notify the cache that the size of a resource has changed.
+     */
+    void didIncreaseResourceSize(const GrResourceCacheEntry*, size_t amountInc);
+    void didDecreaseResourceSize(const GrResourceCacheEntry*, size_t amountDec);
+
+    /**
+     * Remove a resource from the cache and delete it!
+     */
+    void deleteResource(GrResourceCacheEntry* entry);
+
+    /**
+     * Removes every resource in the cache that isn't locked.
+     */
+    void purgeAllUnlocked();
+
+    /**
+     * Allow cache to purge unused resources to obey resource limitations
+     * Note: this entry point will be hidden (again) once totally ref-driven
+     * cache maintenance is implemented. Note that the overbudget callback
+     * will be called if the initial purge doesn't get the cache under
+     * its budget.
+     *
+     * extraCount and extraBytes are added to the current resource allocation
+     * to make sure enough room is available for future additions (e.g,
+     * 10MB across 10 textures is about to be added).
+     */
+    void purgeAsNeeded(int extraCount = 0, size_t extraBytes = 0);
+
+#ifdef SK_DEBUG
+    void validate() const;
+#else
+    void validate() const {}
+#endif
+
+#if GR_CACHE_STATS
+    void printStats();
+#endif
+
+private:
+    void internalDetach(GrResourceCacheEntry*);
+    void attachToHead(GrResourceCacheEntry*);
+    void purgeInvalidated();
+    void internalPurge(int extraCount, size_t extraBytes);
+#ifdef SK_DEBUG
+    static size_t countBytes(const SkTInternalLList<GrResourceCacheEntry>& list);
+#endif
+
+    // We're an internal doubly linked list
+    typedef SkTInternalLList<GrResourceCacheEntry> EntryList;
+    EntryList                               fList;
+
+    // our budget, used in purgeAsNeeded()
+    int                                     fMaxCount;
+    size_t                                  fMaxBytes;
+
+    // our current stats, related to our budget
+#if GR_CACHE_STATS
+    int                                     fHighWaterEntryCount;
+    size_t                                  fHighWaterEntryBytes;
+#endif
+
+    int                                     fEntryCount;
+    size_t                                  fEntryBytes;
+
+    // prevents recursive purging
+    bool                                    fPurging;
+
+    PFOverbudgetCB                          fOverbudgetCB;
+    void*                                   fOverbudgetData;
+
+    SkAutoTUnref<const GrDrawTargetCaps>    fCaps;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+#ifdef SK_DEBUG
+    class GrAutoResourceCacheValidate {
+    public:
+        GrAutoResourceCacheValidate(GrResourceCache* cache) : fCache(cache) {
+            cache->validate();
+        }
+        ~GrAutoResourceCacheValidate() {
+            fCache->validate();
+        }
+    private:
+        GrResourceCache* fCache;
+    };
+#else
+    class GrAutoResourceCacheValidate {
+    public:
+        GrAutoResourceCacheValidate(GrResourceCache*) {}
+    };
+#endif
+
+#endif