Creating a new wrapper for gif decoder

src/codec/SkCodec.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCodec.h"
 #include "SkData.h"
 #include "SkCodec_libbmp.h"
+#include "SkCodec_libgif.h"
 #include "SkCodec_libico.h"
 #include "SkCodec_libpng.h"
+#include "SkCodecPriv.h"
 #include "SkStream.h"
 
 struct DecoderProc {
     bool (*IsFormat)(SkStream*);
     SkCodec* (*NewFromStream)(SkStream*);
 };
 
 static const DecoderProc gDecoderProcs[] = {
     { SkPngCodec::IsPng, SkPngCodec::NewFromStream },
-    { SkIcoCodec::IsIco, SkIcoCodec::NewFromStream },
-    { SkBmpCodec::IsBmp, SkBmpCodec::NewFromStream }
+    { SkGifCodec::IsGif, SkGifCodec::NewFromStream },
+    { SkBmpCodec::IsBmp, SkBmpCodec::NewFromStream },
+    { SkIcoCodec::IsIco, SkIcoCodec::NewFromStream }
 };
 
 SkCodec* SkCodec::NewFromStream(SkStream* stream) {
     if (!stream) {
         return NULL;
     }
+    
+    SkCodec* codec;
     for (uint32_t i = 0; i < SK_ARRAY_COUNT(gDecoderProcs); i++) {
         DecoderProc proc = gDecoderProcs[i];
         const bool correctFormat = proc.IsFormat(stream);
         if (!stream->rewind()) {
             return NULL;
         }
         if (correctFormat) {
-            return proc.NewFromStream(stream);
+            codec = proc.NewFromStream(stream);
+            break;
         }
     }
-    return NULL;
+
+    // Set the max size at 128 MP (512 MB for kN32).

[scroggo, 2015/03/27 13:09:36]

mega pixel?

[msarett, 2015/03/27 14:23:20]

Haha yeah.  I actually googled "megapixel" to find this abbreviation.  If you've
never seen it either, it's probably not widely used.

+    // This is about 4x smaller than a test image that takes a few minutes to
+    // draw.

[scroggo, 2015/03/27 13:09:36]

decode?

[msarett, 2015/03/27 14:23:19]

This is the test with the very, very large frame size and the small subset image
to decode.

I added print statements because I was trying to figure out if it was hanging,
and it didn't look like the decode was taking much time compared to all of the
set up and drawing in dm.  Of course, if we were actually decoding an image of
this size, the decode may take several minutes, I just don't know for sure.

+    const int32_t maxSize = 1 << 27;
+    if (codec != NULL &&
+            codec->getInfo().width() * codec->getInfo().height() > maxSize) {
+        SkCodecPrintf("Error: Image size too large, cannot decode.\n");
+        return NULL;
+    } else {
+        return codec;
+    }
 }
 
 SkCodec* SkCodec::NewFromData(SkData* data) {
     if (!data) {
         return NULL;
     }
     return NewFromStream(SkNEW_ARGS(SkMemoryStream, (data)));
 }
 
 SkCodec::SkCodec(const SkImageInfo& info, SkStream* stream)
@@ skipping 14 matching lines @@
 }
 
 SkScanlineDecoder* SkCodec::getScanlineDecoder(const SkImageInfo& dstInfo) {
     fScanlineDecoder.reset(NULL);
     if (!rewindIfNeeded()) {
         return NULL;
     }
     fScanlineDecoder.reset(this->onGetScanlineDecoder(dstInfo));
     return fScanlineDecoder.get();
 }