Move SkPDFStream back to SkStream to save memory.

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"
@@ skipping 12 matching lines @@
     this->setData(stream);
 }
 
 SkPDFStream::SkPDFStream(SkData* data) : fState(kUnused_State) {
     this->setData(data);
 }
 
 SkPDFStream::SkPDFStream(const SkPDFStream& pdfStream)
         : SkPDFDict(),
           fState(kUnused_State) {
-    this->setData(pdfStream.fData.get());
+    this->setData(pdfStream.fDataStream.get());
     bool removeLength = true;
     // Don't uncompress an already compressed stream, but we could.
     if (pdfStream.fState == kCompressed_State) {
         fState = kCompressed_State;
         removeLength = false;
     }
     this->mergeFrom(pdfStream);
     if (removeLength) {
         this->remove("Length");
     }
 }
 
 SkPDFStream::~SkPDFStream() {}
 
 void SkPDFStream::emitObject(SkWStream* stream, SkPDFCatalog* catalog,
                              bool indirect) {
     if (indirect) {
         return emitIndirectObject(stream, catalog);
     }
     SkAutoMutexAcquire lock(fMutex);  // multiple threads could be calling emit
     if (!this->populate(catalog)) {
         return fSubstitute->emitObject(stream, catalog, indirect);
     }
 
     this->INHERITED::emitObject(stream, catalog, false);
     stream->writeText(" stream\n");
-    if (fData.get()) {
-        stream->write(fData->data(), fData->size());
-    }
+    stream->writeStream(fDataStream.get(), fDataStream->getLength());
+    SkAssertResult(fDataStream->rewind());
     stream->writeText("\nendstream");
 }
 
 size_t SkPDFStream::getOutputSize(SkPDFCatalog* catalog, bool indirect) {
     if (indirect) {
         return getIndirectOutputSize(catalog);
     }
     SkAutoMutexAcquire lock(fMutex);  // multiple threads could be calling emit
     if (!this->populate(catalog)) {
         return fSubstitute->getOutputSize(catalog, indirect);
     }
 
     return this->INHERITED::getOutputSize(catalog, false) +
         strlen(" stream\n\nendstream") + this->dataSize();
 }
 
 SkPDFStream::SkPDFStream() : fState(kUnused_State) {}
 
 void SkPDFStream::setData(SkData* data) {
-    fData.reset(SkSafeRef(data));
+    fMemoryStream.setData(data);
+    if (&fMemoryStream != fDataStream.get()) {
+        fDataStream.reset(SkRef(&fMemoryStream));
+    }
 }
 
 void SkPDFStream::setData(SkStream* stream) {
     // Code assumes that the stream starts at the beginning and is rewindable.
+    if (&fMemoryStream == fDataStream.get()) {
+        SkASSERT(&fMemoryStream != stream);
+        fMemoryStream.setData(NULL);
+    }
+    SkASSERT(0 == fMemoryStream.getLength());
     if (stream) {
-        SkASSERT(stream->getPosition() == 0);
-        fData.reset(SkCopyStreamToData(stream));
-        SkAssertResult(stream->rewind());
+        // SkStreamRewindableFromSkStream will try stream->duplicate().
+        fDataStream.reset(SkStreamRewindableFromSkStream(stream));
+        SkASSERT(fDataStream.get());
     } else {
-        fData.reset(NULL);
+        fDataStream.reset(SkRef(&fMemoryStream));
     }
 }
 
 size_t SkPDFStream::dataSize() const {
-    return fData.get() ? fData->size() : 0;
+    SkASSERT(fDataStream->hasLength());
+    return fDataStream->getLength();
 }
 
 bool SkPDFStream::populate(SkPDFCatalog* catalog) {
     if (fState == kUnused_State) {
         if (!skip_compression(catalog) && SkFlate::HaveFlate()) {
             SkDynamicMemoryWStream compressedData;
 
-            SkAssertResult(SkFlate::Deflate(fData.get(), &compressedData));
+            SkAssertResult(
+                    SkFlate::Deflate(fDataStream.get(), &compressedData));
+            SkAssertResult(fDataStream->rewind());
             if (compressedData.getOffset() < this->dataSize()) {
-                fData.reset(compressedData.copyToData());
+                this->setData(compressedData.detachAsStream());
                 insertName("Filter", "FlateDecode");
             }
             fState = kCompressed_State;
         } else {
             fState = kNoCompression_State;
         }
         insertInt("Length", this->dataSize());
     } else if (fState == kNoCompression_State && !skip_compression(catalog) &&
                SkFlate::HaveFlate()) {
         if (!fSubstitute.get()) {
             fSubstitute.reset(new SkPDFStream(*this));
             catalog->setSubstitute(this, fSubstitute.get());
         }
         return false;
     }
     return true;
 }