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Diffstat (limited to 'external/rapidjson/allocators.h')
-rw-r--r-- | external/rapidjson/allocators.h | 532 |
1 files changed, 271 insertions, 261 deletions
diff --git a/external/rapidjson/allocators.h b/external/rapidjson/allocators.h index 05e3b0cea..98affe03f 100644 --- a/external/rapidjson/allocators.h +++ b/external/rapidjson/allocators.h @@ -1,261 +1,271 @@ -// Tencent is pleased to support the open source community by making RapidJSON available.
-//
-// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
-//
-// Licensed under the MIT License (the "License"); you may not use this file except
-// in compliance with the License. You may obtain a copy of the License at
-//
-// http://opensource.org/licenses/MIT
-//
-// Unless required by applicable law or agreed to in writing, software distributed
-// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
-// CONDITIONS OF ANY KIND, either express or implied. See the License for the
-// specific language governing permissions and limitations under the License.
-
-#ifndef RAPIDJSON_ALLOCATORS_H_
-#define RAPIDJSON_ALLOCATORS_H_
-
-#include "rapidjson.h"
-
-RAPIDJSON_NAMESPACE_BEGIN
-
-///////////////////////////////////////////////////////////////////////////////
-// Allocator
-
-/*! \class rapidjson::Allocator
- \brief Concept for allocating, resizing and freeing memory block.
-
- Note that Malloc() and Realloc() are non-static but Free() is static.
-
- So if an allocator need to support Free(), it needs to put its pointer in
- the header of memory block.
-
-\code
-concept Allocator {
- static const bool kNeedFree; //!< Whether this allocator needs to call Free().
-
- // Allocate a memory block.
- // \param size of the memory block in bytes.
- // \returns pointer to the memory block.
- void* Malloc(size_t size);
-
- // Resize a memory block.
- // \param originalPtr The pointer to current memory block. Null pointer is permitted.
- // \param originalSize The current size in bytes. (Design issue: since some allocator may not book-keep this, explicitly pass to it can save memory.)
- // \param newSize the new size in bytes.
- void* Realloc(void* originalPtr, size_t originalSize, size_t newSize);
-
- // Free a memory block.
- // \param pointer to the memory block. Null pointer is permitted.
- static void Free(void *ptr);
-};
-\endcode
-*/
-
-///////////////////////////////////////////////////////////////////////////////
-// CrtAllocator
-
-//! C-runtime library allocator.
-/*! This class is just wrapper for standard C library memory routines.
- \note implements Allocator concept
-*/
-class CrtAllocator {
-public:
- static const bool kNeedFree = true;
- void* Malloc(size_t size) {
- if (size) // behavior of malloc(0) is implementation defined.
- return std::malloc(size);
- else
- return NULL; // standardize to returning NULL.
- }
- void* Realloc(void* originalPtr, size_t originalSize, size_t newSize) {
- (void)originalSize;
- if (newSize == 0) {
- std::free(originalPtr);
- return NULL;
- }
- return std::realloc(originalPtr, newSize);
- }
- static void Free(void *ptr) { std::free(ptr); }
-};
-
-///////////////////////////////////////////////////////////////////////////////
-// MemoryPoolAllocator
-
-//! Default memory allocator used by the parser and DOM.
-/*! This allocator allocate memory blocks from pre-allocated memory chunks.
-
- It does not free memory blocks. And Realloc() only allocate new memory.
-
- The memory chunks are allocated by BaseAllocator, which is CrtAllocator by default.
-
- User may also supply a buffer as the first chunk.
-
- If the user-buffer is full then additional chunks are allocated by BaseAllocator.
-
- The user-buffer is not deallocated by this allocator.
-
- \tparam BaseAllocator the allocator type for allocating memory chunks. Default is CrtAllocator.
- \note implements Allocator concept
-*/
-template <typename BaseAllocator = CrtAllocator>
-class MemoryPoolAllocator {
-public:
- static const bool kNeedFree = false; //!< Tell users that no need to call Free() with this allocator. (concept Allocator)
-
- //! Constructor with chunkSize.
- /*! \param chunkSize The size of memory chunk. The default is kDefaultChunkSize.
- \param baseAllocator The allocator for allocating memory chunks.
- */
- MemoryPoolAllocator(size_t chunkSize = kDefaultChunkCapacity, BaseAllocator* baseAllocator = 0) :
- chunkHead_(0), chunk_capacity_(chunkSize), userBuffer_(0), baseAllocator_(baseAllocator), ownBaseAllocator_(0)
- {
- }
-
- //! Constructor with user-supplied buffer.
- /*! The user buffer will be used firstly. When it is full, memory pool allocates new chunk with chunk size.
-
- The user buffer will not be deallocated when this allocator is destructed.
-
- \param buffer User supplied buffer.
- \param size Size of the buffer in bytes. It must at least larger than sizeof(ChunkHeader).
- \param chunkSize The size of memory chunk. The default is kDefaultChunkSize.
- \param baseAllocator The allocator for allocating memory chunks.
- */
- MemoryPoolAllocator(void *buffer, size_t size, size_t chunkSize = kDefaultChunkCapacity, BaseAllocator* baseAllocator = 0) :
- chunkHead_(0), chunk_capacity_(chunkSize), userBuffer_(buffer), baseAllocator_(baseAllocator), ownBaseAllocator_(0)
- {
- RAPIDJSON_ASSERT(buffer != 0);
- RAPIDJSON_ASSERT(size > sizeof(ChunkHeader));
- chunkHead_ = reinterpret_cast<ChunkHeader*>(buffer);
- chunkHead_->capacity = size - sizeof(ChunkHeader);
- chunkHead_->size = 0;
- chunkHead_->next = 0;
- }
-
- //! Destructor.
- /*! This deallocates all memory chunks, excluding the user-supplied buffer.
- */
- ~MemoryPoolAllocator() {
- Clear();
- RAPIDJSON_DELETE(ownBaseAllocator_);
- }
-
- //! Deallocates all memory chunks, excluding the user-supplied buffer.
- void Clear() {
- while (chunkHead_ && chunkHead_ != userBuffer_) {
- ChunkHeader* next = chunkHead_->next;
- baseAllocator_->Free(chunkHead_);
- chunkHead_ = next;
- }
- if (chunkHead_ && chunkHead_ == userBuffer_)
- chunkHead_->size = 0; // Clear user buffer
- }
-
- //! Computes the total capacity of allocated memory chunks.
- /*! \return total capacity in bytes.
- */
- size_t Capacity() const {
- size_t capacity = 0;
- for (ChunkHeader* c = chunkHead_; c != 0; c = c->next)
- capacity += c->capacity;
- return capacity;
- }
-
- //! Computes the memory blocks allocated.
- /*! \return total used bytes.
- */
- size_t Size() const {
- size_t size = 0;
- for (ChunkHeader* c = chunkHead_; c != 0; c = c->next)
- size += c->size;
- return size;
- }
-
- //! Allocates a memory block. (concept Allocator)
- void* Malloc(size_t size) {
- if (!size)
- return NULL;
-
- size = RAPIDJSON_ALIGN(size);
- if (chunkHead_ == 0 || chunkHead_->size + size > chunkHead_->capacity)
- AddChunk(chunk_capacity_ > size ? chunk_capacity_ : size);
-
- void *buffer = reinterpret_cast<char *>(chunkHead_) + RAPIDJSON_ALIGN(sizeof(ChunkHeader)) + chunkHead_->size;
- chunkHead_->size += size;
- return buffer;
- }
-
- //! Resizes a memory block (concept Allocator)
- void* Realloc(void* originalPtr, size_t originalSize, size_t newSize) {
- if (originalPtr == 0)
- return Malloc(newSize);
-
- if (newSize == 0)
- return NULL;
-
- // Do not shrink if new size is smaller than original
- if (originalSize >= newSize)
- return originalPtr;
-
- // Simply expand it if it is the last allocation and there is sufficient space
- if (originalPtr == reinterpret_cast<char *>(chunkHead_) + RAPIDJSON_ALIGN(sizeof(ChunkHeader)) + chunkHead_->size - originalSize) {
- size_t increment = static_cast<size_t>(newSize - originalSize);
- increment = RAPIDJSON_ALIGN(increment);
- if (chunkHead_->size + increment <= chunkHead_->capacity) {
- chunkHead_->size += increment;
- return originalPtr;
- }
- }
-
- // Realloc process: allocate and copy memory, do not free original buffer.
- void* newBuffer = Malloc(newSize);
- RAPIDJSON_ASSERT(newBuffer != 0); // Do not handle out-of-memory explicitly.
- if (originalSize)
- std::memcpy(newBuffer, originalPtr, originalSize);
- return newBuffer;
- }
-
- //! Frees a memory block (concept Allocator)
- static void Free(void *ptr) { (void)ptr; } // Do nothing
-
-private:
- //! Copy constructor is not permitted.
- MemoryPoolAllocator(const MemoryPoolAllocator& rhs) /* = delete */;
- //! Copy assignment operator is not permitted.
- MemoryPoolAllocator& operator=(const MemoryPoolAllocator& rhs) /* = delete */;
-
- //! Creates a new chunk.
- /*! \param capacity Capacity of the chunk in bytes.
- */
- void AddChunk(size_t capacity) {
- if (!baseAllocator_)
- ownBaseAllocator_ = baseAllocator_ = RAPIDJSON_NEW(BaseAllocator());
- ChunkHeader* chunk = reinterpret_cast<ChunkHeader*>(baseAllocator_->Malloc(RAPIDJSON_ALIGN(sizeof(ChunkHeader)) + capacity));
- chunk->capacity = capacity;
- chunk->size = 0;
- chunk->next = chunkHead_;
- chunkHead_ = chunk;
- }
-
- static const int kDefaultChunkCapacity = 64 * 1024; //!< Default chunk capacity.
-
- //! Chunk header for perpending to each chunk.
- /*! Chunks are stored as a singly linked list.
- */
- struct ChunkHeader {
- size_t capacity; //!< Capacity of the chunk in bytes (excluding the header itself).
- size_t size; //!< Current size of allocated memory in bytes.
- ChunkHeader *next; //!< Next chunk in the linked list.
- };
-
- ChunkHeader *chunkHead_; //!< Head of the chunk linked-list. Only the head chunk serves allocation.
- size_t chunk_capacity_; //!< The minimum capacity of chunk when they are allocated.
- void *userBuffer_; //!< User supplied buffer.
- BaseAllocator* baseAllocator_; //!< base allocator for allocating memory chunks.
- BaseAllocator* ownBaseAllocator_; //!< base allocator created by this object.
-};
-
-RAPIDJSON_NAMESPACE_END
-
-#endif // RAPIDJSON_ENCODINGS_H_
+// Tencent is pleased to support the open source community by making RapidJSON available. +// +// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved. +// +// Licensed under the MIT License (the "License"); you may not use this file except +// in compliance with the License. You may obtain a copy of the License at +// +// http://opensource.org/licenses/MIT +// +// Unless required by applicable law or agreed to in writing, software distributed +// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR +// CONDITIONS OF ANY KIND, either express or implied. See the License for the +// specific language governing permissions and limitations under the License. + +#ifndef RAPIDJSON_ALLOCATORS_H_ +#define RAPIDJSON_ALLOCATORS_H_ + +#include "rapidjson.h" + +RAPIDJSON_NAMESPACE_BEGIN + +/////////////////////////////////////////////////////////////////////////////// +// Allocator + +/*! \class rapidjson::Allocator + \brief Concept for allocating, resizing and freeing memory block. + + Note that Malloc() and Realloc() are non-static but Free() is static. + + So if an allocator need to support Free(), it needs to put its pointer in + the header of memory block. + +\code +concept Allocator { + static const bool kNeedFree; //!< Whether this allocator needs to call Free(). + + // Allocate a memory block. + // \param size of the memory block in bytes. + // \returns pointer to the memory block. + void* Malloc(size_t size); + + // Resize a memory block. + // \param originalPtr The pointer to current memory block. Null pointer is permitted. + // \param originalSize The current size in bytes. (Design issue: since some allocator may not book-keep this, explicitly pass to it can save memory.) + // \param newSize the new size in bytes. + void* Realloc(void* originalPtr, size_t originalSize, size_t newSize); + + // Free a memory block. + // \param pointer to the memory block. Null pointer is permitted. + static void Free(void *ptr); +}; +\endcode +*/ + +/////////////////////////////////////////////////////////////////////////////// +// CrtAllocator + +//! C-runtime library allocator. +/*! This class is just wrapper for standard C library memory routines. + \note implements Allocator concept +*/ +class CrtAllocator { +public: + static const bool kNeedFree = true; + void* Malloc(size_t size) { + if (size) // behavior of malloc(0) is implementation defined. + return std::malloc(size); + else + return NULL; // standardize to returning NULL. + } + void* Realloc(void* originalPtr, size_t originalSize, size_t newSize) { + (void)originalSize; + if (newSize == 0) { + std::free(originalPtr); + return NULL; + } + return std::realloc(originalPtr, newSize); + } + static void Free(void *ptr) { std::free(ptr); } +}; + +/////////////////////////////////////////////////////////////////////////////// +// MemoryPoolAllocator + +//! Default memory allocator used by the parser and DOM. +/*! This allocator allocate memory blocks from pre-allocated memory chunks. + + It does not free memory blocks. And Realloc() only allocate new memory. + + The memory chunks are allocated by BaseAllocator, which is CrtAllocator by default. + + User may also supply a buffer as the first chunk. + + If the user-buffer is full then additional chunks are allocated by BaseAllocator. + + The user-buffer is not deallocated by this allocator. + + \tparam BaseAllocator the allocator type for allocating memory chunks. Default is CrtAllocator. + \note implements Allocator concept +*/ +template <typename BaseAllocator = CrtAllocator> +class MemoryPoolAllocator { +public: + static const bool kNeedFree = false; //!< Tell users that no need to call Free() with this allocator. (concept Allocator) + + //! Constructor with chunkSize. + /*! \param chunkSize The size of memory chunk. The default is kDefaultChunkSize. + \param baseAllocator The allocator for allocating memory chunks. + */ + MemoryPoolAllocator(size_t chunkSize = kDefaultChunkCapacity, BaseAllocator* baseAllocator = 0) : + chunkHead_(0), chunk_capacity_(chunkSize), userBuffer_(0), baseAllocator_(baseAllocator), ownBaseAllocator_(0) + { + } + + //! Constructor with user-supplied buffer. + /*! The user buffer will be used firstly. When it is full, memory pool allocates new chunk with chunk size. + + The user buffer will not be deallocated when this allocator is destructed. + + \param buffer User supplied buffer. + \param size Size of the buffer in bytes. It must at least larger than sizeof(ChunkHeader). + \param chunkSize The size of memory chunk. The default is kDefaultChunkSize. + \param baseAllocator The allocator for allocating memory chunks. + */ + MemoryPoolAllocator(void *buffer, size_t size, size_t chunkSize = kDefaultChunkCapacity, BaseAllocator* baseAllocator = 0) : + chunkHead_(0), chunk_capacity_(chunkSize), userBuffer_(buffer), baseAllocator_(baseAllocator), ownBaseAllocator_(0) + { + RAPIDJSON_ASSERT(buffer != 0); + RAPIDJSON_ASSERT(size > sizeof(ChunkHeader)); + chunkHead_ = reinterpret_cast<ChunkHeader*>(buffer); + chunkHead_->capacity = size - sizeof(ChunkHeader); + chunkHead_->size = 0; + chunkHead_->next = 0; + } + + //! Destructor. + /*! This deallocates all memory chunks, excluding the user-supplied buffer. + */ + ~MemoryPoolAllocator() { + Clear(); + RAPIDJSON_DELETE(ownBaseAllocator_); + } + + //! Deallocates all memory chunks, excluding the user-supplied buffer. + void Clear() { + while (chunkHead_ && chunkHead_ != userBuffer_) { + ChunkHeader* next = chunkHead_->next; + baseAllocator_->Free(chunkHead_); + chunkHead_ = next; + } + if (chunkHead_ && chunkHead_ == userBuffer_) + chunkHead_->size = 0; // Clear user buffer + } + + //! Computes the total capacity of allocated memory chunks. + /*! \return total capacity in bytes. + */ + size_t Capacity() const { + size_t capacity = 0; + for (ChunkHeader* c = chunkHead_; c != 0; c = c->next) + capacity += c->capacity; + return capacity; + } + + //! Computes the memory blocks allocated. + /*! \return total used bytes. + */ + size_t Size() const { + size_t size = 0; + for (ChunkHeader* c = chunkHead_; c != 0; c = c->next) + size += c->size; + return size; + } + + //! Allocates a memory block. (concept Allocator) + void* Malloc(size_t size) { + if (!size) + return NULL; + + size = RAPIDJSON_ALIGN(size); + if (chunkHead_ == 0 || chunkHead_->size + size > chunkHead_->capacity) + if (!AddChunk(chunk_capacity_ > size ? chunk_capacity_ : size)) + return NULL; + + void *buffer = reinterpret_cast<char *>(chunkHead_) + RAPIDJSON_ALIGN(sizeof(ChunkHeader)) + chunkHead_->size; + chunkHead_->size += size; + return buffer; + } + + //! Resizes a memory block (concept Allocator) + void* Realloc(void* originalPtr, size_t originalSize, size_t newSize) { + if (originalPtr == 0) + return Malloc(newSize); + + if (newSize == 0) + return NULL; + + originalSize = RAPIDJSON_ALIGN(originalSize); + newSize = RAPIDJSON_ALIGN(newSize); + + // Do not shrink if new size is smaller than original + if (originalSize >= newSize) + return originalPtr; + + // Simply expand it if it is the last allocation and there is sufficient space + if (originalPtr == reinterpret_cast<char *>(chunkHead_) + RAPIDJSON_ALIGN(sizeof(ChunkHeader)) + chunkHead_->size - originalSize) { + size_t increment = static_cast<size_t>(newSize - originalSize); + if (chunkHead_->size + increment <= chunkHead_->capacity) { + chunkHead_->size += increment; + return originalPtr; + } + } + + // Realloc process: allocate and copy memory, do not free original buffer. + if (void* newBuffer = Malloc(newSize)) { + if (originalSize) + std::memcpy(newBuffer, originalPtr, originalSize); + return newBuffer; + } + else + return NULL; + } + + //! Frees a memory block (concept Allocator) + static void Free(void *ptr) { (void)ptr; } // Do nothing + +private: + //! Copy constructor is not permitted. + MemoryPoolAllocator(const MemoryPoolAllocator& rhs) /* = delete */; + //! Copy assignment operator is not permitted. + MemoryPoolAllocator& operator=(const MemoryPoolAllocator& rhs) /* = delete */; + + //! Creates a new chunk. + /*! \param capacity Capacity of the chunk in bytes. + \return true if success. + */ + bool AddChunk(size_t capacity) { + if (!baseAllocator_) + ownBaseAllocator_ = baseAllocator_ = RAPIDJSON_NEW(BaseAllocator()); + if (ChunkHeader* chunk = reinterpret_cast<ChunkHeader*>(baseAllocator_->Malloc(RAPIDJSON_ALIGN(sizeof(ChunkHeader)) + capacity))) { + chunk->capacity = capacity; + chunk->size = 0; + chunk->next = chunkHead_; + chunkHead_ = chunk; + return true; + } + else + return false; + } + + static const int kDefaultChunkCapacity = 64 * 1024; //!< Default chunk capacity. + + //! Chunk header for perpending to each chunk. + /*! Chunks are stored as a singly linked list. + */ + struct ChunkHeader { + size_t capacity; //!< Capacity of the chunk in bytes (excluding the header itself). + size_t size; //!< Current size of allocated memory in bytes. + ChunkHeader *next; //!< Next chunk in the linked list. + }; + + ChunkHeader *chunkHead_; //!< Head of the chunk linked-list. Only the head chunk serves allocation. + size_t chunk_capacity_; //!< The minimum capacity of chunk when they are allocated. + void *userBuffer_; //!< User supplied buffer. + BaseAllocator* baseAllocator_; //!< base allocator for allocating memory chunks. + BaseAllocator* ownBaseAllocator_; //!< base allocator created by this object. +}; + +RAPIDJSON_NAMESPACE_END + +#endif // RAPIDJSON_ENCODINGS_H_ |