remove SkWriteBuffer::reserve()

src/core/SkPictureFlat.h

 /*
  * 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 SkPictureFlat_DEFINED
 #define SkPictureFlat_DEFINED
 
 
@@ skipping 145 matching lines @@
 
     void setupBuffer(SkReadBuffer& buffer) const {
         buffer.setFactoryPlayback(fArray, fCount);
     }
 
 private:
     int fCount;
     SkFlattenable::Factory* fArray;
 };
 
-///////////////////////////////////////////////////////////////////////////////
-//
-//
-// The following templated classes provide an efficient way to store and compare
-// objects that have been flattened (i.e. serialized in an ordered binary
-// format).
-//
-// SkFlatData:       is a simple indexable container for the flattened data
-//                   which is agnostic to the type of data is is indexing. It is
-//                   also responsible for flattening/unflattening objects but
-//                   details of that operation are hidden in the provided traits
-// SkFlatDictionary: is an abstract templated dictionary that maintains a
-//                   searchable set of SkFlatData objects of type T.
-// SkFlatController: is an interface provided to SkFlatDictionary which handles
-//                   allocation (and unallocation in some cases). It also holds
-//                   ref count recorders and the like.
-//
-// NOTE: any class that wishes to be used in conjunction with SkFlatDictionary must subclass the
-// dictionary and provide the necessary flattening traits.  SkFlatController must also be
-// implemented, or SkChunkFlatController can be used to use an SkChunkAllocator and never do
-// replacements.
-//
-//
-///////////////////////////////////////////////////////////////////////////////
-
-class SkFlatData;
-
-class SkFlatController : public SkRefCnt {
-public:
-
-
-    SkFlatController(uint32_t writeBufferFlags = 0);
-    virtual ~SkFlatController();
-    /**
-     * Return a new block of memory for the SkFlatDictionary to use.
-     * This memory is owned by the controller and has the same lifetime unless you
-     * call unalloc(), in which case it may be freed early.
-     */
-    virtual void* allocThrow(size_t bytes) = 0;
-
-    /**
-     * Hint that this block, which was allocated with allocThrow, is no longer needed.
-     * The implementation may choose to free this memory any time beteween now and destruction.
-     */
-    virtual void unalloc(void* ptr) = 0;
-
-    /**
-     * Used during creation and unflattening of SkFlatData objects. If the
-     * objects being flattened contain bitmaps they are stored in this heap
-     * and the flattenable stores the index to the bitmap on the heap.
-     * This should be set by the protected setBitmapHeap.
-     */
-    SkBitmapHeap* getBitmapHeap() { return fBitmapHeap; }
-
-    /**
-     * Used during creation of SkFlatData objects. If a typeface recorder is
-     * required to flatten the objects being flattened (i.e. for SkPaints), this
-     * should be set by the protected setTypefaceSet.
-     */
-    SkRefCntSet* getTypefaceSet() { return fTypefaceSet; }
-
-    /**
-     * Used during unflattening of the SkFlatData objects in the
-     * SkFlatDictionary. Needs to be set by the protected setTypefacePlayback
-     * and needs to be reset to the SkRefCntSet passed to setTypefaceSet.
-     */
-    SkTypefacePlayback* getTypefacePlayback() { return fTypefacePlayback; }
-
-    /**
-     * Flags to use during creation of SkFlatData objects. Defaults to zero.
-     */
-    uint32_t getWriteBufferFlags() { return fWriteBufferFlags; }
-
-protected:
-    /**
-     * Set an SkBitmapHeap to be used to store/read SkBitmaps. Ref counted.
-     */
-    void setBitmapHeap(SkBitmapHeap*);
-
-    /**
-     * Set an SkRefCntSet to be used to store SkTypefaces during flattening. Ref
-     * counted.
-     */
-    void setTypefaceSet(SkRefCntSet*);
-
-    /**
-     * Set an SkTypefacePlayback to be used to find references to SkTypefaces
-     * during unflattening. Should be reset to the set provided to
-     * setTypefaceSet.
-     */
-    void setTypefacePlayback(SkTypefacePlayback*);
-
-private:
-    SkBitmapHeap*       fBitmapHeap;
-    SkRefCntSet*        fTypefaceSet;
-    SkTypefacePlayback* fTypefacePlayback;
-    const uint32_t      fWriteBufferFlags;
-
-    typedef SkRefCnt INHERITED;
-};
-
-class SkFlatData {
-public:
-    // Flatten obj into an SkFlatData with this index.  controller owns the SkFlatData*.
-    template <typename Traits, typename T>
-    static SkFlatData* Create(SkFlatController* controller, const T& obj, int index) {
-        // A buffer of 256 bytes should fit most paints, regions, and matrices.
-        uint32_t storage[64];
-        SkWriteBuffer buffer(storage, sizeof(storage), controller->getWriteBufferFlags());
-
-        buffer.setBitmapHeap(controller->getBitmapHeap());
-        buffer.setTypefaceRecorder(controller->getTypefaceSet());
-
-        Traits::Flatten(buffer, obj);
-        size_t size = buffer.bytesWritten();
-        SkASSERT(SkIsAlign4(size));
-
-        // Allocate enough memory to hold SkFlatData struct and the flat data itself.
-        size_t allocSize = sizeof(SkFlatData) + size;
-        SkFlatData* result = (SkFlatData*) controller->allocThrow(allocSize);
-
-        // Put the serialized contents into the data section of the new allocation.
-        buffer.writeToMemory(result->data());
-        // Stamp the index, size and checksum in the header.
-        result->stampHeader(index, SkToS32(size));
-        return result;
-    }
-
-    // Unflatten this into result, using bitmapHeap and facePlayback for bitmaps and fonts if given
-    template <typename Traits, typename T>
-    void unflatten(T* result,
-                   SkBitmapHeap* bitmapHeap = nullptr,
-                   SkTypefacePlayback* facePlayback = nullptr) const {
-        SkReadBuffer buffer(this->data(), fFlatSize);
-
-        if (bitmapHeap) {
-            buffer.setBitmapStorage(bitmapHeap);
-        }
-        if (facePlayback) {
-            facePlayback->setupBuffer(buffer);
-        }
-
-        Traits::Unflatten(buffer, result);
-        SkASSERT(fFlatSize == (int32_t)buffer.offset());
-    }
-
-    // Do these contain the same data?  Ignores index() and topBot().
-    bool operator==(const SkFlatData& that) const {
-        if (this->checksum() != that.checksum() || this->flatSize() != that.flatSize()) {
-            return false;
-        }
-        return memcmp(this->data(), that.data(), this->flatSize()) == 0;
-    }
-
-    int index() const { return fIndex; }
-    const uint8_t* data() const { return (const uint8_t*)this + sizeof(*this); }
-    size_t flatSize() const { return fFlatSize; }
-    uint32_t checksum() const { return fChecksum; }
-
-    // Returns true if fTopBot[] has been recorded.
-    bool isTopBotWritten() const {
-        return !SkScalarIsNaN(fTopBot[0]);
-    }
-
-    // Returns fTopBot array, so it can be passed to a routine to compute them.
-    // For efficiency, we assert that fTopBot have not been recorded yet.
-    SkScalar* writableTopBot() const {
-        SkASSERT(!this->isTopBotWritten());
-        return fTopBot;
-    }
-
-    // Return the topbot[] after it has been recorded.
-    const SkScalar* topBot() const {
-        SkASSERT(this->isTopBotWritten());
-        return fTopBot;
-    }
-
-private:
-    struct HashTraits {
-        static const SkFlatData& GetKey(const SkFlatData& flat) { return flat; }
-        static uint32_t Hash(const SkFlatData& flat) { return flat.checksum(); }
-    };
-
-    void setIndex(int index) { fIndex = index; }
-    uint8_t* data() { return (uint8_t*)this + sizeof(*this); }
-
-    // This assumes the payload flat data has already been written and does not modify it.
-    void stampHeader(int index, int32_t size) {
-        SkASSERT(SkIsAlign4(size));
-        fIndex     = index;
-        fFlatSize  = size;
-        fTopBot[0] = SK_ScalarNaN;  // Mark as unwritten.
-        fChecksum  = SkChecksum::Murmur3(this->data(), size);
-    }
-
-    int fIndex;
-    int32_t fFlatSize;
-    uint32_t fChecksum;
-    mutable SkScalar fTopBot[2];  // Cache of FontMetrics fTop, fBottom.  Starts as [NaN,?].
-    // uint32_t flattenedData[] implicitly hangs off the end.
-
-    template <typename T, typename Traits> friend class SkFlatDictionary;
-};
-
-template <typename T, typename Traits>
-class SkFlatDictionary {
-public:
-    explicit SkFlatDictionary(SkFlatController* controller)
-    : fController(SkRef(controller))
-    , fScratch(controller->getWriteBufferFlags())
-    , fReady(false) {
-        this->reset();
-    }
-
-    /**
-     * Clears the dictionary of all entries. However, it does NOT free the
-     * memory that was allocated for each entry (that's owned by controller).
-     */
-    void reset() {
-        fIndexedData.rewind();
-    }
-
-    int count() const {
-        SkASSERT(fHash.count() == fIndexedData.count());
-        return fHash.count();
-    }
-
-    // For testing only.  Index is zero-based.
-    const SkFlatData* operator[](int index) {
-        return fIndexedData[index];
-    }
-
-    /**
-     * Given an element of type T return its 1-based index in the dictionary. If
-     * the element wasn't previously in the dictionary it is automatically
-     * added.
-     *
-     */
-    int find(const T& element) {
-        return this->findAndReturnFlat(element)->index();
-    }
-
-    /**
-     * Similar to find. Allows the caller to specify an SkFlatData to replace in
-     * the case of an add. Also tells the caller whether a new SkFlatData was
-     * added and whether the old one was replaced. The parameters added and
-     * replaced are required to be non-nullptr. Rather than returning the index of
-     * the entry in the dictionary, it returns the actual SkFlatData.
-     */
-    const SkFlatData* findAndReplace(const T& element,
-                                     const SkFlatData* toReplace,
-                                     bool* added,
-                                     bool* replaced) {
-        SkASSERT(added != nullptr && replaced != nullptr);
-
-        const int oldCount = this->count();
-        SkFlatData* flat = this->findAndReturnMutableFlat(element);
-        *added = this->count() > oldCount;
-
-        // If we don't want to replace anything, we're done.
-        if (!*added || toReplace == nullptr) {
-            *replaced = false;
-            return flat;
-        }
-
-        // If we don't have the thing to replace, we're done.
-        const SkFlatData* found = fHash.find(*toReplace);
-        if (found == nullptr) {
-            *replaced = false;
-            return flat;
-        }
-
-        // findAndReturnMutableFlat put flat at the back.  Swap it into found->index() instead.
-        // indices in SkFlatData are 1-based, while fIndexedData is 0-based.  Watch out!
-        SkASSERT(flat->index() == this->count());
-        flat->setIndex(found->index());
-        fIndexedData.removeShuffle(found->index()-1);
-        SkASSERT(flat == fIndexedData[found->index()-1]);
-
-        // findAndReturnMutableFlat already called fHash.add(), so we just clean up the old entry.
-        fHash.remove(*found);
-        fController->unalloc((void*)found);
-        SkASSERT(this->count() == oldCount);
-
-        *replaced = true;
-        return flat;
-    }
-
-    /**
-     * Unflatten the specific object at the given index.
-     * Caller takes ownership of the result.
-     */
-    T* unflatten(int index) const {
-        // index is 1-based, while fIndexedData is 0-based.
-        const SkFlatData* element = fIndexedData[index-1];
-        SkASSERT(index == element->index());
-
-        T* dst = new T;
-        this->unflatten(dst, element);
-        return dst;
-    }
-
-    /**
-     * Find or insert a flattened version of element into the dictionary.
-     * Caller does not take ownership of the result.  This will not return nullptr.
-     */
-    const SkFlatData* findAndReturnFlat(const T& element) {
-        return this->findAndReturnMutableFlat(element);
-    }
-
-private:
-    // We have to delay fScratch's initialization until its first use; fController might not
-    // be fully set up by the time we get it in the constructor.
-    void lazyInit() {
-        if (fReady) {
-            return;
-        }
-
-        // Without a bitmap heap, we'll flatten bitmaps into paints.  That's never what you want.
-        SkASSERT(fController->getBitmapHeap() != nullptr);
-        fScratch.setBitmapHeap(fController->getBitmapHeap());
-        fScratch.setTypefaceRecorder(fController->getTypefaceSet());
-        fReady = true;
-    }
-
-    // As findAndReturnFlat, but returns a mutable pointer for internal use.
-    SkFlatData* findAndReturnMutableFlat(const T& element) {
-        // Only valid until the next call to resetScratch().
-        const SkFlatData& scratch = this->resetScratch(element, this->count()+1);
-
-        SkFlatData* candidate = fHash.find(scratch);
-        if (candidate != nullptr) {
-            return candidate;
-        }
-
-        SkFlatData* detached = this->detachScratch();
-        fHash.add(detached);
-        *fIndexedData.append() = detached;
-        SkASSERT(fIndexedData.top()->index() == this->count());
-        return detached;
-    }
-
-    // This reference is valid only until the next call to resetScratch() or detachScratch().
-    const SkFlatData& resetScratch(const T& element, int index) {
-        this->lazyInit();
-
-        // Layout of fScratch: [ SkFlatData header, 20 bytes ] [ data ..., 4-byte aligned ]
-        fScratch.reset();
-        fScratch.reserve(sizeof(SkFlatData));
-        Traits::Flatten(fScratch, element);
-        const size_t dataSize = fScratch.bytesWritten() - sizeof(SkFlatData);
-
-        // Reinterpret data in fScratch as an SkFlatData.
-        SkFlatData* scratch = (SkFlatData*)fScratch.getWriter32()->contiguousArray();
-        SkASSERT(scratch != nullptr);
-        scratch->stampHeader(index, SkToS32(dataSize));
-        return *scratch;
-    }
-
-    // This result is owned by fController and lives as long as it does (unless unalloc'd).
-    SkFlatData* detachScratch() {
-        // Allocate a new SkFlatData exactly big enough to hold our current scratch.
-        // We use the controller for this allocation to extend the allocation's lifetime and allow
-        // the controller to do whatever memory management it wants.
-        SkFlatData* detached = (SkFlatData*)fController->allocThrow(fScratch.bytesWritten());
-
-        // Copy scratch into the new SkFlatData.
-        SkFlatData* scratch = (SkFlatData*)fScratch.getWriter32()->contiguousArray();
-        SkASSERT(scratch != nullptr);
-        memcpy(detached, scratch, fScratch.bytesWritten());
-
-        // We can now reuse fScratch, and detached will live until fController dies.
-        return detached;
-    }
-
-    void unflatten(T* dst, const SkFlatData* element) const {
-        element->unflatten<Traits>(dst,
-                                   fController->getBitmapHeap(),
-                                   fController->getTypefacePlayback());
-    }
-
-    // All SkFlatData* stored in fIndexedData and fHash are owned by the controller.
-    SkAutoTUnref<SkFlatController> fController;
-    SkWriteBuffer fScratch;
-    bool fReady;
-
-    // For index -> SkFlatData.  0-based, while all indices in the API are 1-based.  Careful!
-    SkTDArray<const SkFlatData*> fIndexedData;
-
-    // For SkFlatData -> cached SkFlatData, which has index().
-    SkTDynamicHash<SkFlatData, SkFlatData, SkFlatData::HashTraits> fHash;
-};
-
 #endif