SkPDF: Memory improvements for PDF Streams

src/pdf/SkPDFStream.cpp

 
 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkData.h"
 #include "SkDeflate.h"
 #include "SkPDFStream.h"
 #include "SkStream.h"
 #include "SkStreamPriv.h"
 
 SkPDFStream::~SkPDFStream() {}
 
 void SkPDFStream::emitObject(SkWStream* stream,
                              const SkPDFObjNumMap& objNumMap,
                              const SkPDFSubstituteMap& substitutes) const {
     SkASSERT(fCompressedData);
     this->INHERITED::emitObject(stream, objNumMap, substitutes);
-    // Note: emitObject isn't marked const, but could be in the future
+    // duplicate (a cheap operation) preserves const on fCompressedData.
     SkAutoTDelete<SkStreamRewindable> dup(fCompressedData->duplicate());
     SkASSERT(dup);
     SkASSERT(dup->hasLength());
     stream->writeText(" stream\n");
     stream->writeStream(dup.get(), dup->getLength());
     stream->writeText("\nendstream");
 }
 
 void SkPDFStream::setData(SkStream* stream) {
     SkASSERT(!fCompressedData);  // Only call this function once.
@@ skipping 12 matching lines @@
             dup->getLength() <= length + strlen("/Filter_/FlateDecode_")) {
             this->insertInt("Length", dup->getLength());
             fCompressedData.reset(dup.detach());
             return;
         }
     }
     fCompressedData.reset(compressedData.detachAsStream());
     this->insertName("Filter", "FlateDecode");
     this->insertInt("Length", length);
 }