Remove SkBitmapHeap and SkBitmapHeapReader. They're unused.

src/core/SkBitmapHeap.h

-/*
- * Copyright 2012 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef SkBitmapHeap_DEFINED
-#define SkBitmapHeap_DEFINED
-
-#include "SkAtomics.h"
-#include "SkBitmap.h"
-#include "SkPoint.h"
-#include "SkRefCnt.h"
-#include "SkTDArray.h"
-#include "SkTypes.h"
-
-/**
- * SkBitmapHeapEntry provides users of SkBitmapHeap (using internal storage) with a means to...
- *  (1) get access a bitmap in the heap
- *  (2) indicate they are done with bitmap by releasing their reference (if they were an owner).
- */
-class SkBitmapHeapEntry : SkNoncopyable {
-public:
-    ~SkBitmapHeapEntry();
-
-    int32_t getSlot() { return fSlot; }
-
-    SkBitmap* getBitmap() { return &fBitmap; }
-
-    void releaseRef() {
-        sk_atomic_dec(&fRefCount);
-    }
-
-private:
-    SkBitmapHeapEntry();
-
-    void addReferences(int count);
-
-    int32_t fSlot;
-    int32_t fRefCount;
-
-    SkBitmap fBitmap;
-    // Keep track of the bytes allocated for this bitmap. When replacing the
-    // bitmap or removing this HeapEntry we know how much memory has been
-    // reclaimed.
-    size_t fBytesAllocated;
-
-    friend class SkBitmapHeap;
-    friend class SkBitmapHeapTester;
-};
-
-
-class SkBitmapHeapReader : public SkRefCnt {
-public:
-
-
-    SkBitmapHeapReader() : INHERITED() {}
-    virtual SkBitmap* getBitmap(int32_t slot) const = 0;
-    virtual void releaseRef(int32_t slot) = 0;
-private:
-    typedef SkRefCnt INHERITED;
-};
-
-
-/**
- * TODO: stores immutable bitmaps into a heap
- */
-class SkBitmapHeap : public SkBitmapHeapReader {
-public:
-    class ExternalStorage : public SkRefCnt {
-     public:
-
-
-        virtual bool insert(const SkBitmap& bitmap, int32_t slot) = 0;
-
-     private:
-        typedef SkRefCnt INHERITED;
-    };
-
-    static const int32_t UNLIMITED_SIZE = -1;
-    static const int32_t IGNORE_OWNERS  = -1;
-    static const int32_t INVALID_SLOT   = -1;
-
-    /**
-     * Constructs a heap that is responsible for allocating and managing its own storage.  In the
-     * case where we choose to allow the heap to grow indefinitely (i.e. UNLIMITED_SIZE) we
-     * guarantee that once allocated in the heap a bitmap's index in the heap is immutable.
-     * Otherwise we guarantee the bitmaps placement in the heap until its owner count goes to zero.
-     *
-     * @param preferredSize  Specifies the preferred maximum number of bitmaps to store. This is
-     *   not a hard limit as it can grow larger if the number of bitmaps in the heap with active
-     *   owners exceeds this limit.
-     * @param ownerCount  The number of owners to assign to each inserted bitmap. NOTE: while a
-     *   bitmap in the heap has a least one owner it can't be removed.
-     */
-    SkBitmapHeap(int32_t preferredSize = UNLIMITED_SIZE, int32_t ownerCount = IGNORE_OWNERS);
-
-    /**
-     * Constructs a heap that defers the responsibility of storing the bitmaps to an external
-     * function. This is especially useful if the bitmaps will be used in a separate process as the
-     * external storage can ensure the data is properly shuttled to the appropriate processes.
-     *
-     * Our LRU implementation assumes that inserts into the external storage are consumed in the
-     * order that they are inserted (i.e. SkPipe). This ensures that we don't need to query the
-     * external storage to see if a slot in the heap is eligible to be overwritten.
-     *
-     * @param externalStorage  The class responsible for storing the bitmaps inserted into the heap
-     * @param heapSize  The maximum size of the heap. Because of the sequential limitation imposed
-     *   by our LRU implementation we can guarantee that the heap will never grow beyond this size.
-     */
-    SkBitmapHeap(ExternalStorage* externalStorage, int32_t heapSize = UNLIMITED_SIZE);
-
-    virtual ~SkBitmapHeap();
-
-    /**
-     * Retrieves the bitmap from the specified slot in the heap
-     *
-     * @return  The bitmap located at that slot or nullptr if external storage is being used.
-     */
-    SkBitmap* getBitmap(int32_t slot) const override {
-        SkASSERT(fExternalStorage == nullptr);
-        SkBitmapHeapEntry* entry = getEntry(slot);
-        if (entry) {
-            return &entry->fBitmap;
-        }
-        return nullptr;
-    }
-
-    /**
-     * Retrieves the bitmap from the specified slot in the heap
-     *
-     * @return  The bitmap located at that slot or nullptr if external storage is being used.
-     */
-    void releaseRef(int32_t slot) override {
-        SkASSERT(fExternalStorage == nullptr);
-        if (fOwnerCount != IGNORE_OWNERS) {
-            SkBitmapHeapEntry* entry = getEntry(slot);
-            if (entry) {
-                entry->releaseRef();
-            }
-        }
-    }
-
-    /**
-     * Inserts a bitmap into the heap. The stored version of bitmap is guaranteed to be immutable
-     * and is not dependent on the lifecycle of the provided bitmap.
-     *
-     * @param bitmap  the bitmap to be inserted into the heap
-     * @return  the slot in the heap where the bitmap is stored or INVALID_SLOT if the bitmap could
-     *          not be added to the heap. If it was added the slot will remain valid...
-     *            (1) indefinitely if no owner count has been specified.
-     *            (2) until all owners have called releaseRef on the appropriate SkBitmapHeapEntry*
-     */
-    int32_t insert(const SkBitmap& bitmap);
-
-    /**
-     * Retrieves an entry from the heap at a given slot.
-     *
-     * @param slot  the slot in the heap where a bitmap was stored.
-     * @return  a SkBitmapHeapEntry that wraps the bitmap or nullptr if external storage is used.
-     */
-    SkBitmapHeapEntry* getEntry(int32_t slot) const {
-        SkASSERT(slot <= fStorage.count());
-        if (fExternalStorage != nullptr) {
-            return nullptr;
-        }
-        return fStorage[slot];
-    }
-
-    /**
-     * Returns a count of the number of items currently in the heap
-     */
-    int count() const {
-        SkASSERT(fExternalStorage != nullptr ||
-                 fStorage.count() - fUnusedSlots.count() == fLookupTable.count());
-        return fLookupTable.count();
-    }
-
-    /**
-     * Returns the total number of bytes allocated by the bitmaps in the heap
-     */
-    size_t bytesAllocated() const {
-        return fBytesAllocated;
-    }
-
-    /**
-     * Attempt to reduce the storage allocated.
-     * @param bytesToFree minimum number of bytes that should be attempted to
-     *   be freed.
-     * @return number of bytes actually freed.
-     */
-    size_t freeMemoryIfPossible(size_t bytesToFree);
-
-    /**
-     * Defer any increments of owner counts until endAddingOwnersDeferral is called. So if an
-     * existing SkBitmap is inserted into the SkBitmapHeap, its corresponding SkBitmapHeapEntry will
-     * not have addReferences called on it, and the client does not need to make a corresponding
-     * call to releaseRef. Only meaningful if this SkBitmapHeap was created with an owner count not
-     * equal to IGNORE_OWNERS.
-     */
-    void deferAddingOwners();
-
-    /**
-     * Resume adding references when duplicate SkBitmaps are inserted.
-     * @param add If true, add references to the SkBitmapHeapEntrys whose SkBitmaps were re-inserted
-     *            while deferring.
-     */
-    void endAddingOwnersDeferral(bool add);
-
-private:
-    struct LookupEntry {
-        LookupEntry(const SkBitmap& bm)
-        : fGenerationId(bm.getGenerationID())
-        , fPixelOrigin(bm.pixelRefOrigin())
-        , fWidth(bm.width())
-        , fHeight(bm.height())
-        , fMoreRecentlyUsed(nullptr)
-        , fLessRecentlyUsed(nullptr){}
-
-        const uint32_t fGenerationId; // SkPixelRef GenerationID.
-        const SkIPoint fPixelOrigin;
-        const uint32_t fWidth;
-        const uint32_t fHeight;
-
-        // TODO: Generalize the LRU caching mechanism
-        LookupEntry* fMoreRecentlyUsed;
-        LookupEntry* fLessRecentlyUsed;
-
-        uint32_t fStorageSlot; // slot of corresponding bitmap in fStorage.
-
-        /**
-         * Compare two LookupEntry pointers for sorting and searching.
-         */
-        static bool Less(const LookupEntry& a, const LookupEntry& b);
-    };
-
-    /**
-     * Remove the entry from the lookup table. Also deletes the entry pointed
-     * to by the table. Therefore, if a pointer to that one was passed in, the
-     * pointer should no longer be used, since the object to which it points has
-     * been deleted.
-     * @return The index in the lookup table of the entry before removal.
-     */
-    int removeEntryFromLookupTable(LookupEntry*);
-
-    /**
-     * Searches for the bitmap in the lookup table and returns the bitmaps index within the table.
-     * If the bitmap was not already in the table it is added.
-     *
-     * @param key    The key to search the lookup table, created from a bitmap.
-     * @param entry  A pointer to a SkBitmapHeapEntry* that if non-null AND the bitmap is found
-     *               in the lookup table is populated with the entry from the heap storage.
-     */
-    int findInLookupTable(const LookupEntry& key, SkBitmapHeapEntry** entry);
-
-    LookupEntry* findEntryToReplace(const SkBitmap& replacement);
-    bool copyBitmap(const SkBitmap& originalBitmap, SkBitmap& copiedBitmap);
-
-    /**
-     * Remove a LookupEntry from the LRU, in preparation for either deleting or appending as most
-     * recent. Points the LookupEntry's old neighbors at each other, and sets fLeastRecentlyUsed
-     * (if there is still an entry left). Sets LookupEntry's fMoreRecentlyUsed to nullptr and leaves
-     * its fLessRecentlyUsed unmodified.
-     */
-    void removeFromLRU(LookupEntry* entry);
-
-    /**
-     * Append a LookupEntry to the end of the LRU cache, marking it as the most
-     * recently used. Assumes that the LookupEntry is already in fLookupTable,
-     * but is not in the LRU cache. If it is in the cache, removeFromLRU should
-     * be called first.
-     */
-    void appendToLRU(LookupEntry*);
-
-    // searchable index that maps to entries in the heap
-    SkTDArray<LookupEntry*> fLookupTable;
-
-    // heap storage
-    SkTDArray<SkBitmapHeapEntry*> fStorage;
-    // Used to mark slots in fStorage as deleted without actually deleting
-    // the slot so as not to mess up the numbering.
-    SkTDArray<int> fUnusedSlots;
-    ExternalStorage* fExternalStorage;
-
-    LookupEntry* fMostRecentlyUsed;
-    LookupEntry* fLeastRecentlyUsed;
-
-    const int32_t fPreferredCount;
-    const int32_t fOwnerCount;
-    size_t fBytesAllocated;
-
-    bool fDeferAddingOwners;
-    SkTDArray<int> fDeferredEntries;
-
-    typedef SkBitmapHeapReader INHERITED;
-};
-
-#endif // SkBitmapHeap_DEFINED