Move SkPDFStream back to SkStream to save memory.

src/core/SkStream.cpp

 
 /*
  * Copyright 2006 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 "SkStream.h"
@@ skipping 889 matching lines @@
 
     SkDynamicMemoryWStream tempStream;
     const size_t bufferSize = 4096;
     char buffer[bufferSize];
     do {
         size_t bytesRead = stream->read(buffer, bufferSize);
         tempStream.write(buffer, bytesRead);
     } while (!stream->isAtEnd());
     return tempStream.copyToData();
 }
+
+SkStreamRewindable* SkStreamRewindableFromSkStream(SkStream* stream) {
+    if (!stream) {
+        return NULL;
+    }
+    SkAutoTUnref<SkStreamRewindable> dupStream(stream->duplicate());
+    if (dupStream) {
+        return dupStream.detach();
+    }
+    stream->rewind();
+    if (stream->hasLength()) {
+        size_t length = stream->getLength();
+        if (stream->hasPosition()) {  // If stream has length, but can't rewind.
+            length -= stream->getPosition();
+        }
+        SkAutoMalloc allocMemory(length);
+        SkDEBUGCODE(size_t read =) stream->read(allocMemory.get(), length);
+        SkASSERT(length == read);
+        SkAutoTUnref<SkData> data(
+                SkData::NewFromMalloc(allocMemory.detach(), length));
+        return SkNEW_ARGS(SkMemoryStream, (data.get()));
+    }
+    SkDynamicMemoryWStream tempStream;
+    const size_t bufferSize = 4096;
+    char buffer[bufferSize];
+    do {
+        size_t bytesRead = stream->read(buffer, bufferSize);
+        tempStream.write(buffer, bytesRead);
+    } while (!stream->isAtEnd());
+    return tempStream.detachAsStream();  // returns a SkBlockMemoryStream,
+                                         // cheaper than copying to SkData
+}