MemoryBuffer.h (2364B)
1 // 2 // Copyright 2014 The ANGLE Project Authors. All rights reserved. 3 // Use of this source code is governed by a BSD-style license that can be 4 // found in the LICENSE file. 5 // 6 7 #ifndef COMMON_MEMORYBUFFER_H_ 8 #define COMMON_MEMORYBUFFER_H_ 9 10 #include "common/Optional.h" 11 #include "common/angleutils.h" 12 #include "common/debug.h" 13 14 #include <stdint.h> 15 #include <cstddef> 16 17 namespace angle 18 { 19 20 class MemoryBuffer final : NonCopyable 21 { 22 public: 23 MemoryBuffer() = default; 24 ~MemoryBuffer(); 25 26 MemoryBuffer(MemoryBuffer &&other); 27 MemoryBuffer &operator=(MemoryBuffer &&other); 28 29 [[nodiscard]] bool resize(size_t size); 30 void clear() { (void)resize(0); } 31 size_t size() const { return mSize; } 32 bool empty() const { return mSize == 0; } 33 34 const uint8_t *data() const { return mData; } 35 uint8_t *data() 36 { 37 ASSERT(mData); 38 return mData; 39 } 40 41 uint8_t &operator[](size_t pos) 42 { 43 ASSERT(pos < mSize); 44 return mData[pos]; 45 } 46 const uint8_t &operator[](size_t pos) const 47 { 48 ASSERT(pos < mSize); 49 return mData[pos]; 50 } 51 52 void fill(uint8_t datum); 53 54 private: 55 size_t mSize = 0; 56 uint8_t *mData = nullptr; 57 }; 58 59 class ScratchBuffer final : NonCopyable 60 { 61 public: 62 // If we request a scratch buffer requesting a smaller size this many times, release and 63 // recreate the scratch buffer. This ensures we don't have a degenerate case where we are stuck 64 // hogging memory. 65 ScratchBuffer(); 66 ScratchBuffer(uint32_t lifetime); 67 ~ScratchBuffer(); 68 69 ScratchBuffer(ScratchBuffer &&other); 70 ScratchBuffer &operator=(ScratchBuffer &&other); 71 72 // Returns true with a memory buffer of the requested size, or false on failure. 73 bool get(size_t requestedSize, MemoryBuffer **memoryBufferOut); 74 75 // Same as get, but ensures new values are initialized to a fixed constant. 76 bool getInitialized(size_t requestedSize, MemoryBuffer **memoryBufferOut, uint8_t initValue); 77 78 // Ticks the release counter for the scratch buffer. Also done implicitly in get(). 79 void tick(); 80 81 void clear(); 82 83 private: 84 bool getImpl(size_t requestedSize, MemoryBuffer **memoryBufferOut, Optional<uint8_t> initValue); 85 86 uint32_t mLifetime; 87 uint32_t mResetCounter; 88 MemoryBuffer mScratchMemory; 89 }; 90 91 } // namespace angle 92 93 #endif // COMMON_MEMORYBUFFER_H_