Index: third_party/WebKit/Source/platform/image-decoders/png/PNGImageReader.h |
diff --git a/third_party/WebKit/Source/platform/image-decoders/png/PNGImageReader.h b/third_party/WebKit/Source/platform/image-decoders/png/PNGImageReader.h |
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index 0000000000000000000000000000000000000000..3fe939c6f0d51c7bd9ce25ff21210cd169e8a3dd |
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+/* |
+ * Copyright (C) 2006 Apple Computer, Inc. All rights reserved. |
+ * |
+ * Redistribution and use in source and binary forms, with or without |
+ * modification, are permitted provided that the following conditions |
+ * are met: |
+ * 1. Redistributions of source code must retain the above copyright |
+ * notice, this list of conditions and the following disclaimer. |
+ * 2. Redistributions in binary form must reproduce the above copyright |
+ * notice, this list of conditions and the following disclaimer in the |
+ * documentation and/or other materials provided with the distribution. |
+ * |
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY |
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR |
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
+ */ |
+ |
+ |
+#include "platform/image-decoders/SegmentReader.h" |
+#include "platform/image-decoders/png/PNGImageDecoder.h" |
+#include "platform/PlatformExport.h" |
+#include "png.h" |
+#include "wtf/Allocator.h" |
+#include "wtf/PtrUtil.h" |
+ |
+#ifndef PNGImageReader_h |
+#define PNGImageReader_h |
+ |
+namespace blink { |
+ |
+class FastSharedBufferReader; |
+ |
+class PLATFORM_EXPORT PNGImageReader final { |
+ USING_FAST_MALLOC(PNGImageReader); |
+ WTF_MAKE_NONCOPYABLE(PNGImageReader); |
+ |
+ public: |
+ PNGImageReader(PNGImageDecoder*, size_t initialOffset); |
+ ~PNGImageReader(); |
+ |
+ struct FrameInfo { |
+ // The offset where the frame data of this frame starts. |
+ size_t startOffset; |
+ // The number of bytes that contain frame data, starting at startOffset. |
+ size_t byteLength; |
+ size_t duration; |
+ IntRect frameRect; |
+ uint8_t disposalMethod; |
+ uint8_t alphaBlend; |
+ }; |
+ |
+ |
+ // This method tries to parse the data stream in the SegmentReader, up to |
+ // the point where the PNGParseQuery can be answered. |
+ // @return true when the query is fulfilled. |
+ // false when: |
+ // A) not enough data provided |
+ // B) the data processing by libpng fails. In this case, it also |
+ // calls setFailed() on m_decoder. |
+ bool parse(SegmentReader&, PNGImageDecoder::PNGParseQuery); |
+ |
+ void decode(SegmentReader&, size_t); |
+ const FrameInfo& frameInfo(size_t) const; |
+ |
+ // This will return the number of frames that have been detected in the |
+ // stream so far. If an incomplete stream is provided, this number is not |
+ // final. However, all frame info for the frames up to this number is |
+ // available so it can be used by the client if it wants to. |
+ size_t frameCount() const; |
+ |
+ // This is a callback for libpng, when it encounters an unknown chunk. |
+ void parseAnimationChunk(const char* tag, const void* dataChunk, size_t length); |
+ |
+ // |m_parseCompleted| becomes true when |
+ // a) the png is determined to be non-animated, if no acTL chunk is found |
+ // before the IDAT chunk, or |
+ // b) when the IEND chunk is seen for animated pngs. |
+ bool parseCompleted() const { return m_parseCompleted; }; |
+ |
+ // This method is called when a frame with status ImageFrame::FramePartial |
+ // gets cleared in PNGImageDecoder. |
+ // |
+ // For |frameIndex| > 0, no action is necessary, since each decode call will |
+ // decode the frame completely from start to end. |
+ // |
+ // For |frameIndex| == 0, |m_progressiveDecodeOffset| will be set to 0, to |
+ // make sure progressive decoding is started from the beginning of the frame. |
+ void clearDecodeState(size_t frameIndex); |
+ |
+ png_structp pngPtr() const { return m_png; } |
+ png_infop infoPtr() const { return m_info; } |
+ |
+ png_bytep interlaceBuffer() const { return m_interlaceBuffer.get(); } |
+ void createInterlaceBuffer(int size) { |
+ m_interlaceBuffer = wrapArrayUnique(new png_byte[size]); |
+ } |
+ void clearInterlaceBuffer() { m_interlaceBuffer.reset(); } |
+ |
+ private: |
+ png_structp m_png; |
+ png_infop m_info; |
+ PNGImageDecoder* m_decoder; |
+ // This indicates at what offset in the stream the PNG image starts. |
+ const size_t m_initialOffset; |
+ // This is used to keep track of how many bytes we've read during parsing. |
+ size_t m_readOffset; |
+ |
+ // This variable is used to do progressive decoding for the first frame. It |
+ // keeps track of how many bytes have been processed so far. |
+ size_t m_progressiveDecodeOffset; |
+ // The offset where IDAT starts. This is used to re-use the complete set of |
+ // info/header chunks when mimicking a png image for a frame. |
+ size_t m_idatOffset; |
+ // This flag is set to true when an fcTL chunk is encountered before the |
+ // IDAT chunk(s). In that case, the IDAT data is the first frame. Otherwise, |
+ // the IDAT is ignored for an animated image. |
+ bool m_idatIsPartOfAnimation; |
+ bool m_isAnimated; |
+ bool m_parsedSignature; |
+ bool m_parseCompleted; |
+ |
+ std::unique_ptr<png_byte[]> m_interlaceBuffer; |
+ |
+ Vector<FrameInfo, 1> m_frameInfo; |
+ // This is used to temporarily store frame information, until it is pushed to |
+ // |m_frameInfo|, when all frame data has been seen in the stream. |
+ FrameInfo m_newFrame; |
+ |
+ size_t processData(SegmentReader&, size_t offset, size_t length); |
+ bool parseSize(SegmentReader&); |
+ void parseFrameInfo(const png_byte* data); |
+ void startFrameDecoding(SegmentReader&, size_t); |
+ // @return true if the complete frame has been decoded |
+ // false otherwise |
+ bool progressivelyDecodeFirstFrame(SegmentReader&); |
+ void decodeFrame(SegmentReader&, size_t); |
+ void endFrameDecoding(); |
+ |
+}; |
+ |
+}; |
+ |
+#endif |