| /* |
| * 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 SkRWBuffer_DEFINED |
| #define SkRWBuffer_DEFINED |
| |
| #include "SkRefCnt.h" |
| |
| struct SkBufferBlock; |
| struct SkBufferHead; |
| class SkRWBuffer; |
| class SkStreamAsset; |
| |
| /** |
| * Contains a read-only, thread-sharable block of memory. To access the memory, the caller must |
| * instantiate a local iterator, as the memory is stored in 1 or more contiguous blocks. |
| */ |
| class SkROBuffer : public SkRefCnt { |
| public: |
| /** |
| * Return the logical length of the data owned/shared by this buffer. It may be stored in |
| * multiple contiguous blocks, accessible via the iterator. |
| */ |
| size_t size() const { return fUsed; } |
| |
| class Iter { |
| public: |
| Iter(const SkROBuffer*); |
| |
| void reset(const SkROBuffer*); |
| |
| /** |
| * Return the current continuous block of memory, or NULL if the iterator is exhausted |
| */ |
| const void* data() const; |
| |
| /** |
| * Returns the number of bytes in the current continguous block of memory, or 0 if the |
| * iterator is exhausted. |
| */ |
| size_t size() const; |
| |
| /** |
| * Advance to the next contiguous block of memory, returning true if there is another |
| * block, or false if the iterator is exhausted. |
| */ |
| bool next(); |
| |
| private: |
| const SkBufferBlock* fBlock; |
| size_t fRemaining; |
| }; |
| |
| private: |
| SkROBuffer(const SkBufferHead* head, size_t used); |
| virtual ~SkROBuffer(); |
| |
| const SkBufferHead* fHead; |
| const size_t fUsed; |
| |
| friend class SkRWBuffer; |
| }; |
| |
| /** |
| * Accumulates bytes of memory that are "appended" to it, growing internal storage as needed. |
| * The growth is done such that at any time, a RBuffer or StreamAsset can be snapped off, which |
| * can see the previously stored bytes, but which will be unaware of any future writes. |
| */ |
| class SkRWBuffer { |
| public: |
| SkRWBuffer(size_t initialCapacity = 0); |
| ~SkRWBuffer(); |
| |
| size_t size() const { return fTotalUsed; } |
| void append(const void* buffer, size_t length); |
| void* append(size_t length); |
| |
| SkROBuffer* newRBufferSnapshot() const; |
| SkStreamAsset* newStreamSnapshot() const; |
| |
| #ifdef SK_DEBUG |
| void validate() const; |
| #else |
| void validate() const {} |
| #endif |
| |
| private: |
| SkBufferHead* fHead; |
| SkBufferBlock* fTail; |
| size_t fTotalUsed; |
| }; |
| |
| #endif |