SkJpegCodec

src/codec/SkJpegAutoClean.h

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkJpegAutoClean_DEFINED
+#define SkJpegAutoClean_DEFINED
+
+#include "SkTemplates.h"
+#include <stdio.h>

[scroggo, 2015/04/10 17:19:05]

We should not be using stdio.

[msarett, 2015/04/13 20:54:04]

jpeglib has some sort of odd dependence on stdio.  SkImageDecoder_libjpeg uses
this include as well.

+extern "C" {

[scroggo, 2015/04/10 17:19:05]

For our other codec headers, we've discovered that the headers themselves use
use extern C, so this ended up not being necessary. Not sure whether that is the
case here.

[msarett, 2015/04/13 20:54:04]

Looks like that is the case here.

+    #include "jpeglib.h"
+}
+
+/*
+ * This object automatically cleans up memory after a jpeg decode
+ */
+class JpegAutoClean {

[scroggo, 2015/04/10 17:19:05]

This should inherit from SkNoncopyable.

[msarett, 2015/04/13 20:54:04]

Done.

+public:
+
+    /*
+     * Takes ownership of jpegInfo pointer.
+     */
+    JpegAutoClean(jpeg_decompress_struct* jpegInfo, bool init);

[scroggo, 2015/04/10 17:19:05]

nit: Traditionally, jpeg_decompress_struct is named cinfo. At least, I thought
so - looking in the Chromium code base, it looks like sometimes it is called
dinfo, ci, and info...

[msarett, 2015/04/13 20:54:04]

Maybe for "compress info" and "decompress info"?  I changed the name because
cinfo didn't really mean anything to me.  I think I'll go with dinfo.  Happy to
tweak this again if my guess about the names is off the mark.

+    
+    /*
+     * Frees the owned jpeg_decompress_struct pointer as well as any allocated memory
+     * that is referenced in the jpeg_decompress_struct.
+     */
+    ~JpegAutoClean();
+
+    /*
+     * Indicates if the jpeg info struct has been initialized with data.
+     */
+    void setInit(bool init);
+
+    /*
+     * Get the jpeg info pointer.
+     * Retains ownership of the jpeg_decompress_struct pointer.
+     */
+    jpeg_decompress_struct* get();
+
+    /*
+     * Detach the jpeg_decompress_struct pointer.
+     * It is now owned by the caller.
+     */
+    jpeg_decompress_struct* detach();
+
+    /*
+     * Reset the pointer that is owned by this object.
+     * This will free the original pointer and takes ownership of the pointer passed
+     * as an argument.
+     */
+    void reset(jpeg_decompress_struct* jpegInfo);
+
+private:
+
+    /*
+     * Frees the owned jpeg_decompress_struct pointer as well as any allocated memory
+     * that is referenced in the jpeg_decompress_struct.
+     */
+    void free();
+
+    SkAutoTDelete<jpeg_decompress_struct> fJpegInfo;
+    bool                                  fInit;
+};
+
+#endif