Hide implementation details: SkFrontBufferedStream
R=reed@google.com
Review URL: https://codereview.chromium.org/25581002
git-svn-id: http://skia.googlecode.com/svn/trunk/include@12256 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/utils/SkFrontBufferedStream.h b/utils/SkFrontBufferedStream.h
index e3eb4db..68d9861 100644
--- a/utils/SkFrontBufferedStream.h
+++ b/utils/SkFrontBufferedStream.h
@@ -5,73 +5,31 @@
* found in the LICENSE file.
*/
-#include "SkStream.h"
-#include "SkTemplates.h"
+#include "SkTypes.h"
+
+class SkStream;
+class SkStreamRewindable;
/**
- * Specialized stream that only buffers the first X bytes of a stream,
+ * Specialized stream that buffers the first X bytes of a stream,
* where X is passed in by the user. Note that unlike some buffered
- * stream APIs, once more than those bytes are read, no more buffering
- * is done. This stream is designed for a use case where the caller
- * knows that rewind will only be called from within X bytes (inclusive),
- * and the wrapped stream is not necessarily able to rewind at all.
+ * stream APIs, once more bytes than can fit in the buffer are read,
+ * no more buffering is done. This stream is designed for a use case
+ * where the caller knows that rewind will only be called from within
+ * X bytes (inclusive), and the wrapped stream is not necessarily
+ * able to rewind at all.
*/
-class SkFrontBufferedStream : public SkStreamRewindable {
+class SkFrontBufferedStream {
public:
/**
- * Creates a new stream that wraps and buffers SkStream.
- * @param stream SkStream to buffer. If NULL, NULL is returned. After
- * this call, unref stream and do not refer to it.
- * SkFrontBufferedStream is expected to be its only owner.
- * @param bufferSize Exact size of the buffer to be used.
- * @return An SkStream that can buffer up to bufferSize.
+ * Creates a new stream that wraps and buffers an SkStream.
+ * @param stream SkStream to buffer. If stream is NULL, NULL is
+ * returned. When this call succeeds (i.e. returns non NULL),
+ * SkFrontBufferedStream is expected to be the only owner of
+ * stream, so it should be unreffed and no longer used directly.
+ * @param minBufferSize Minimum size of buffer required.
+ * @return An SkStream that can buffer at least minBufferSize, or
+ * NULL on failure.
*/
- static SkStreamRewindable* Create(SkStream* stream, size_t bufferSize);
-
- virtual size_t read(void* buffer, size_t size) SK_OVERRIDE;
-
- virtual bool isAtEnd() const SK_OVERRIDE;
-
- virtual bool rewind() SK_OVERRIDE;
-
- virtual bool hasPosition() const SK_OVERRIDE { return true; }
-
- virtual size_t getPosition() const SK_OVERRIDE { return fOffset; }
-
- virtual bool hasLength() const SK_OVERRIDE;
-
- virtual size_t getLength() const SK_OVERRIDE;
-
- virtual SkStreamRewindable* duplicate() const SK_OVERRIDE { return NULL; }
-
-private:
- SkAutoTUnref<SkStream> fStream;
- // Current offset into the stream. Always >= 0.
- size_t fOffset;
- // Amount that has been buffered by calls to read. Will always be less than
- // fBufferSize.
- size_t fBufferedSoFar;
- // Total size of the buffer.
- const size_t fBufferSize;
- SkAutoTMalloc<char> fBuffer;
-
- // Private. Use Create.
- SkFrontBufferedStream(SkStream*, size_t bufferSize);
-
- // Read up to size bytes from already buffered data, and copy to
- // dst, if non-NULL. Updates fOffset. Assumes that fOffset is less
- // than fBufferedSoFar.
- size_t readFromBuffer(char* dst, size_t size);
-
- // Buffer up to size bytes from the stream, and copy to dst if non-
- // NULL. Updates fOffset and fBufferedSoFar. Assumes that fOffset is
- // less than fBufferedSoFar, and size is greater than 0.
- size_t bufferAndWriteTo(char* dst, size_t size);
-
- // Read up to size bytes directly from the stream and into dst if non-
- // NULL. Updates fOffset. Assumes fOffset is at or beyond the buffered
- // data, and size is greater than 0.
- size_t readDirectlyFromStream(char* dst, size_t size);
-
- typedef SkStream INHERITED;
+ static SkStreamRewindable* Create(SkStream* stream, size_t minBufferSize);
};
