Change SkImageDecoders to take an SkStreamRewindable.

src/images/SkImageDecoder_libjpeg.cpp

 /*
  * Copyright 2007 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkImageDecoder.h"
 #include "SkImageEncoder.h"
@@ skipping 47 matching lines @@
     SkASSERT(cinfo != NULL);
     SkASSERT(src_mgr != NULL);
     jpeg_create_decompress(cinfo);
     overwrite_mem_buffer_size(cinfo);
     cinfo->src = src_mgr;
 }
 
 #ifdef SK_BUILD_FOR_ANDROID
 class SkJPEGImageIndex {
 public:
-    SkJPEGImageIndex(SkStream* stream, SkImageDecoder* decoder)
+    SkJPEGImageIndex(SkStreamRewindable* stream, SkImageDecoder* decoder)
         : fSrcMgr(stream, decoder)
         , fInfoInitialized(false)
         , fHuffmanCreated(false)
         , fDecompressStarted(false)
         {
             SkDEBUGCODE(fReadHeaderSucceeded = false;)
         }
 
     ~SkJPEGImageIndex() {
         if (fHuffmanCreated) {
@@ skipping 109 matching lines @@
         SkDELETE(fImageIndex);
     }
 #endif
 
     virtual Format getFormat() const {
         return kJPEG_Format;
     }
 
 protected:
 #ifdef SK_BUILD_FOR_ANDROID
-    virtual bool onBuildTileIndex(SkStream *stream, int *width, int *height) SK_OVERRIDE;
+    virtual bool onBuildTileIndex(SkStreamRewindable *stream, int *width, int *height) SK_OVERRIDE;
     virtual bool onDecodeSubset(SkBitmap* bitmap, const SkIRect& rect) SK_OVERRIDE;
 #endif
     virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE;
 
 private:
 #ifdef SK_BUILD_FOR_ANDROID
     SkJPEGImageIndex* fImageIndex;
     int fImageWidth;
     int fImageHeight;
 #endif
@@ skipping 421 matching lines @@
     if (!skip_src_rows(&cinfo, srcRow,
                        cinfo.output_height - cinfo.output_scanline)) {
         return return_false(cinfo, *bm, "skip rows");
     }
     jpeg_finish_decompress(&cinfo);
 
     return true;
 }
 
 #ifdef SK_BUILD_FOR_ANDROID
-bool SkJPEGImageDecoder::onBuildTileIndex(SkStream* stream, int *width, int *height) {
+bool SkJPEGImageDecoder::onBuildTileIndex(SkStreamRewindable* stream, int *width, int *height) {
 
     SkAutoTDelete<SkJPEGImageIndex> imageIndex(SkNEW_ARGS(SkJPEGImageIndex, (stream, this)));
     jpeg_decompress_struct* cinfo = imageIndex->cinfo();
 
     skjpeg_error_mgr sk_err;
     set_error_mgr(cinfo, &sk_err);
 
     // All objects need to be instantiated before this setjmp call so that
     // they will be cleaned up properly if an error occurs.
     if (setjmp(sk_err.fJmpBuf)) {
@@ skipping 462 matching lines @@
 
         return true;
     }
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 DEFINE_DECODER_CREATOR(JPEGImageDecoder);
 DEFINE_ENCODER_CREATOR(JPEGImageEncoder);
 ///////////////////////////////////////////////////////////////////////////////
 
-static bool is_jpeg(SkStream* stream) {
+static bool is_jpeg(SkStreamRewindable* stream) {
     static const unsigned char gHeader[] = { 0xFF, 0xD8, 0xFF };
     static const size_t HEADER_SIZE = sizeof(gHeader);
 
     char buffer[HEADER_SIZE];
     size_t len = stream->read(buffer, HEADER_SIZE);
 
     if (len != HEADER_SIZE) {
         return false;   // can't read enough
     }
     if (memcmp(buffer, gHeader, HEADER_SIZE)) {
         return false;
     }
     return true;
 }
 
-static SkImageDecoder* sk_libjpeg_dfactory(SkStream* stream) {
+
+static SkImageDecoder* sk_libjpeg_dfactory(SkStreamRewindable* stream) {
     if (is_jpeg(stream)) {
         return SkNEW(SkJPEGImageDecoder);
     }
     return NULL;
 }
 
-static SkImageDecoder::Format get_format_jpeg(SkStream* stream) {
+static SkImageDecoder::Format get_format_jpeg(SkStreamRewindable* stream) {
     if (is_jpeg(stream)) {
         return SkImageDecoder::kJPEG_Format;
     }
     return SkImageDecoder::kUnknown_Format;
 }
 
 static SkImageEncoder* sk_libjpeg_efactory(SkImageEncoder::Type t) {
     return (SkImageEncoder::kJPEG_Type == t) ? SkNEW(SkJPEGImageEncoder) : NULL;
 }
 
-
 static SkImageDecoder_DecodeReg gDReg(sk_libjpeg_dfactory);
 static SkImageDecoder_FormatReg gFormatReg(get_format_jpeg);
 static SkImageEncoder_EncodeReg gEReg(sk_libjpeg_efactory);