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author | 2013-11-12 20:53:05 +0000 | |
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committer | 2013-11-12 20:53:05 +0000 | |
commit | 09a5383adc59c3798f6f6e851f46320393b6c4b8 (patch) | |
tree | 232fd917dbf3268a07befa82c471afc8d8ceeb49 /include/utils/SkFrontBufferedStream.h | |
parent | 367028330a2589373e80c94b0ada2d5b608e0bd0 (diff) |
Hide implementation details: SkFrontBufferedStream
R=reed@google.com
Review URL: https://codereview.chromium.org/25581002
git-svn-id: http://skia.googlecode.com/svn/trunk@12256 2bbb7eff-a529-9590-31e7-b0007b416f81
Diffstat (limited to 'include/utils/SkFrontBufferedStream.h')
-rw-r--r-- | include/utils/SkFrontBufferedStream.h | 82 |
1 files changed, 20 insertions, 62 deletions
diff --git a/include/utils/SkFrontBufferedStream.h b/include/utils/SkFrontBufferedStream.h index e3eb4dbad1..68d9861557 100644 --- a/include/utils/SkFrontBufferedStream.h +++ b/include/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); }; |