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* SkStreamToStreamRewindable(SkStream* stream) {

[bungeman-skia, 2014/07/11 21:43:38]

I would prefer this to be SkStreamRewindableFromSkStream so that 1) it looks
more like a constructor call and 2) the parts of the name are closer to the
values they refer to. On the other hand, the other functions here use the
backward 'To' form, so I can't be too ornery.

[hal.canary, 2014/07/12 00:58:49]

Done.

+    if (!stream) {
+        return NULL;
+    }
+    SkAutoTUnref<SkStreamRewindable> dupStream(stream->duplicate());
+    if (dupStream) {
+        return dupStream.detach();
+    }
+    if (stream->hasLength()) {
+        size_t length = stream->getLength();
+        SkAutoMalloc allocMemory(length);
+        SkAssertResult(stream->rewind());

[bungeman-skia, 2014/07/11 21:43:38]

I wouldn't assert this, just because a stream has a length doesn't imply that
it's rewindable (though I must admit that it seems unlikely). I think I would
just 'stream->rewind()' before this 'if' block and remove the
'SkAssertResult(stream->rewind());' below (line 929).

Then, if 'hasPosition' you can subtract that from the length.

[hal.canary, 2014/07/12 00:58:49]

Done.

+        SkAssertResult(length == stream->read(allocMemory.get(), length));
+        SkAssertResult(stream->rewind());

[bungeman-skia, 2014/07/11 21:43:38]

I see no reason to try to leave this in a known state, since other paths do not.
I wouldn't bother with this and just comment that the passed stream is left at
an unknown position.

[hal.canary, 2014/07/12 00:58:49]

Done.

+        SkAutoTUnref<SkData> data(
+                SkData::NewFromMalloc(allocMemory.get(), length));
+        return SkNEW_ARGS(SkMemoryStream, (data.get()));
+    }
+    SkAssertResult(stream->rewind());
+    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());
+    SkAssertResult(stream->rewind());

[bungeman-skia, 2014/07/11 21:43:38]

Same as above (line 924), I see no reason to try to rewind anything just to
leave the stream in a known state.

[hal.canary, 2014/07/12 00:58:49]

Done.

+    return tempStream.detachAsStream();  // returns a SkBlockMemoryStream,
+                                         // cheaper than copying to SkData
+}