2 files changed, 50 insertions, 67 deletions

diff --git a/WebCore/platform/image-decoders/png/PNGImageDecoder.cpp b/WebCore/platform/image-decoders/png/PNGImageDecoder.cpp
index ad79fc8..35c8af0 100644
--- a/WebCore/platform/image-decoders/png/PNGImageDecoder.cpp
+++ b/WebCore/platform/image-decoders/png/PNGImageDecoder.cpp
@@ -1,6 +1,7 @@
 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  * Copyright (C) 2007-2009 Torch Mobile, Inc.
+ * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  *
  * Portions are Copyright (C) 2001 mozilla.org
  *
@@ -39,7 +40,6 @@
 #include "config.h"
 #include "PNGImageDecoder.h"
 #include "png.h"
-#include "assert.h"
 
 namespace WebCore {
 
@@ -76,6 +76,8 @@ public:
         , m_decodingSizeOnly(false)
         , m_interlaceBuffer(0)
         , m_hasAlpha(0)
+        , m_hasFinishedDecoding(false)
+        , m_currentBufferSize(0)
     {
         m_png = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, decodingFailed, decodingWarning);
         m_info = png_create_info_struct(m_png);
@@ -93,9 +95,14 @@ public:
         delete []m_interlaceBuffer;
         m_interlaceBuffer = 0;
         m_readOffset = 0;
+        m_hasFinishedDecoding = false;
     }
 
-    void decode(const Vector<char>& data, bool sizeOnly)
+    unsigned currentBufferSize() const { return m_currentBufferSize; }
+
+    void setComplete() { m_hasFinishedDecoding = true; }
+
+    void decode(const SharedBuffer& data, bool sizeOnly)
     {
         m_decodingSizeOnly = sizeOnly;
 
@@ -105,13 +112,17 @@ public:
             return;
         }
 
-        // Go ahead and assume we consumed all the data.  If we consume less, the
-        // callback will adjust our read offset accordingly.  Do not attempt to adjust the
-        // offset after png_process_data returns.
-        unsigned offset = m_readOffset;
-        unsigned remaining = data.size() - m_readOffset;
-        m_readOffset = data.size();
-        png_process_data(m_png, m_info, (png_bytep)(data.data()) + offset, remaining);
+        PNGImageDecoder* decoder = static_cast<PNGImageDecoder*>(png_get_progressive_ptr(m_png));
+        const char* segment;
+        while (unsigned segmentLength = data.getSomeData(segment, m_readOffset)) {
+            m_readOffset += segmentLength;
+            m_currentBufferSize = m_readOffset;
+            png_process_data(m_png, m_info, reinterpret_cast<png_bytep>(const_cast<char*>(segment)), segmentLength);
+            if ((sizeOnly && decoder->isSizeAvailable()) || m_hasFinishedDecoding)
+                return;
+        }
+        if (!m_hasFinishedDecoding && decoder->isAllDataReceived())
+            decoder->pngComplete();
     }
 
     bool decodingSizeOnly() const { return m_decodingSizeOnly; }
@@ -134,16 +145,16 @@ private:
     png_infop m_info;
     png_bytep m_interlaceBuffer;
     bool m_hasAlpha;
+    bool m_hasFinishedDecoding;
+    unsigned m_currentBufferSize;
 };
 
 PNGImageDecoder::PNGImageDecoder()
-    : m_reader(0)
 {
 }
 
 PNGImageDecoder::~PNGImageDecoder()
 {
-    delete m_reader;
 }
 
 // Take the data and store it.
@@ -157,7 +168,7 @@ void PNGImageDecoder::setData(SharedBuffer* data, bool allDataReceived)
 
     // Create the PNG reader.
     if (!m_reader && !m_failed)
-        m_reader = new PNGImageReader(this);
+        m_reader.set(new PNGImageReader(this));
 }
 
 // Whether or not the size information has been decoded yet.
@@ -190,12 +201,10 @@ void PNGImageDecoder::decode(bool sizeOnly)
     if (m_failed)
         return;
 
-    m_reader->decode(m_data->buffer(), sizeOnly);
+    m_reader->decode(*m_data, sizeOnly);
     
-    if (m_failed || (!m_frameBufferCache.isEmpty() && m_frameBufferCache[0].status() == RGBA32Buffer::FrameComplete)) {
-        delete m_reader;
-        m_reader = 0;
-    }
+    if (m_failed || (!m_frameBufferCache.isEmpty() && m_frameBufferCache[0].status() == RGBA32Buffer::FrameComplete))
+        m_reader.clear();
 }
 
 void decodingFailed(png_structp png, png_const_charp errorMsg)
@@ -224,8 +233,8 @@ void PNGImageDecoder::decodingFailed()
 
 void PNGImageDecoder::headerAvailable()
 {
-    png_structp png = reader()->pngPtr();
-    png_infop info = reader()->infoPtr();
+    png_structp png = m_reader->pngPtr();
+    png_infop info = m_reader->infoPtr();
     png_uint_32 width = png->width;
     png_uint_32 height = png->height;
     
@@ -243,9 +252,7 @@ void PNGImageDecoder::headerAvailable()
             longjmp(png->jmpbuf, 1);
             return;
         }
-#if ENABLE(IMAGE_DECODER_DOWN_SAMPLING)
         prepareScaleDataIfNecessary();
-#endif
     }
 
     int bitDepth, colorType, interlaceType, compressionType, filterType, channels;
@@ -292,13 +299,13 @@ void PNGImageDecoder::headerAvailable()
     // Update our info now
     png_read_update_info(png, info);
     channels = png_get_channels(png, info);
-    assert(channels == 3 || channels == 4);
+    ASSERT(channels == 3 || channels == 4);
 
-    reader()->setHasAlpha(channels == 4);
+    m_reader->setHasAlpha(channels == 4);
 
-    if (reader()->decodingSizeOnly()) {
+    if (m_reader->decodingSizeOnly()) {
         // If we only needed the size, halt the reader.     
-        reader()->setReadOffset(m_data->size() - png->buffer_size);
+        m_reader->setReadOffset(m_reader->currentBufferSize() - png->buffer_size);
         png->buffer_size = 0;
     }
 }
@@ -317,16 +324,9 @@ void PNGImageDecoder::rowAvailable(unsigned char* rowBuffer, unsigned rowIndex,
     // Initialize the framebuffer if needed.
     RGBA32Buffer& buffer = m_frameBufferCache[0];
     if (buffer.status() == RGBA32Buffer::FrameEmpty) {
-#if ENABLE(IMAGE_DECODER_DOWN_SAMPLING)
-        int width = m_scaled ? m_scaledColumns.size() : size().width();
-        int height = m_scaled ? m_scaledRows.size() : size().height();
-#else
-        int width = size().width();
-        int height = size().height();
-#endif
-        if (!buffer.setSize(width, height)) {
-            static_cast<PNGImageDecoder*>(png_get_progressive_ptr(reader()->pngPtr()))->decodingFailed();
-            longjmp(reader()->pngPtr()->jmpbuf, 1);
+        if (!buffer.setSize(scaledSize().width(), scaledSize().height())) {
+            static_cast<PNGImageDecoder*>(png_get_progressive_ptr(m_reader->pngPtr()))->decodingFailed();
+            longjmp(m_reader->pngPtr()->jmpbuf, 1);
             return;
         }
         buffer.setStatus(RGBA32Buffer::FramePartial);
@@ -335,8 +335,8 @@ void PNGImageDecoder::rowAvailable(unsigned char* rowBuffer, unsigned rowIndex,
         // For PNGs, the frame always fills the entire image.
         buffer.setRect(IntRect(IntPoint(), size()));
 
-        if (reader()->pngPtr()->interlaced)
-            reader()->createInterlaceBuffer((reader()->hasAlpha() ? 4 : 3) * size().width() * size().height());
+        if (m_reader->pngPtr()->interlaced)
+            m_reader->createInterlaceBuffer((m_reader->hasAlpha() ? 4 : 3) * size().width() * size().height());
     }
 
     if (rowBuffer == 0)
@@ -370,11 +370,11 @@ void PNGImageDecoder::rowAvailable(unsigned char* rowBuffer, unsigned rowIndex,
     * old row and the new row.
     */
 
-    png_structp png = reader()->pngPtr();
-    bool hasAlpha = reader()->hasAlpha();
+    png_structp png = m_reader->pngPtr();
+    bool hasAlpha = m_reader->hasAlpha();
     unsigned colorChannels = hasAlpha ? 4 : 3;
     png_bytep row;
-    png_bytep interlaceBuffer = reader()->interlaceBuffer();
+    png_bytep interlaceBuffer = m_reader->interlaceBuffer();
     if (interlaceBuffer) {
         row = interlaceBuffer + (rowIndex * colorChannels * size().width());
         png_progressive_combine_row(png, row, rowBuffer);
@@ -383,33 +383,15 @@ void PNGImageDecoder::rowAvailable(unsigned char* rowBuffer, unsigned rowIndex,
         row = rowBuffer;
 
     // Copy the data into our buffer.
-#if ENABLE(IMAGE_DECODER_DOWN_SAMPLING)
-    if (m_scaled) {
-        int destY = scaledY(rowIndex);
-        if (destY < 0)
-            return;
-        int columns = m_scaledColumns.size();
-        bool sawAlpha = buffer.hasAlpha();
-        for (int x = 0; x < columns; ++x) {
-            png_bytep pixel = row + m_scaledColumns[x] * 4;
-            unsigned alpha = pixel[3];
-            buffer.setRGBA(x, destY, pixel[0], pixel[1], pixel[2], alpha);
-            if (!sawAlpha && alpha < 255) {
-                sawAlpha = true;
-                buffer.setHasAlpha(true);
-            }
-        }
+    int width = scaledSize().width();
+    int destY = scaledY(rowIndex);
+    if (destY < 0)
         return;
-    }
-#endif
-    int width = size().width();
     bool sawAlpha = buffer.hasAlpha();
     for (int x = 0; x < width; x++) {
-        unsigned red = *row++;
-        unsigned green = *row++;
-        unsigned blue = *row++;
-        unsigned alpha = (hasAlpha ? *row++ : 255);
-        buffer.setRGBA(x, rowIndex, red, green, blue, alpha);
+        png_bytep pixel = row + (m_scaled ? m_scaledColumns[x] : x) * colorChannels;
+        unsigned alpha = hasAlpha ? pixel[3] : 255;
+        buffer.setRGBA(x, destY, pixel[0], pixel[1], pixel[2], alpha);
         if (!sawAlpha && alpha < 255) {
             sawAlpha = true;
             buffer.setHasAlpha(true);
@@ -424,6 +406,8 @@ void pngComplete(png_structp png, png_infop info)
 
 void PNGImageDecoder::pngComplete()
 {
+    m_reader->setComplete();
+
     if (m_frameBufferCache.isEmpty())
         return;
 
diff --git a/WebCore/platform/image-decoders/png/PNGImageDecoder.h b/WebCore/platform/image-decoders/png/PNGImageDecoder.h
index 3c0535b..07a0b3a 100644
--- a/WebCore/platform/image-decoders/png/PNGImageDecoder.h
+++ b/WebCore/platform/image-decoders/png/PNGImageDecoder.h
@@ -27,6 +27,7 @@
 #define PNGImageDecoder_h
 
 #include "ImageDecoder.h"
+#include <wtf/OwnPtr.h>
 
 namespace WebCore {
 
@@ -50,8 +51,6 @@ namespace WebCore {
 
         void decode(bool sizeOnly = false);
 
-        PNGImageReader* reader() { return m_reader; }
-
         // Callbacks from libpng
         void decodingFailed();
         void headerAvailable();
@@ -59,7 +58,7 @@ namespace WebCore {
         void pngComplete();
 
     private:
-        PNGImageReader* m_reader;
+        OwnPtr<PNGImageReader> m_reader;
     };
 
 } // namespace WebCore