skia2/include/core/SkChunkAlloc.h
robertphillips a9061de9ff Add rewind capability to SkChunkAlloc
Split off from https://codereview.chromium.org/940533003/ (Decrease GrInOrderDrawBuffer::Cmd's reliance on GrInOrderDrawBuffer)

Review URL: https://codereview.chromium.org/967553003
2015-02-27 08:31:57 -08:00

79 lines
2.2 KiB
C++

/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkChunkAlloc_DEFINED
#define SkChunkAlloc_DEFINED
#include "SkTypes.h"
class SkChunkAlloc : SkNoncopyable {
public:
SkChunkAlloc(size_t minSize);
~SkChunkAlloc();
/**
* Free up all allocated blocks. This invalidates all returned
* pointers.
*/
void reset();
/**
* Reset to 0 used bytes preserving as much memory as possible.
* This invalidates all returned pointers.
*/
void rewind();
enum AllocFailType {
kReturnNil_AllocFailType,
kThrow_AllocFailType
};
void* alloc(size_t bytes, AllocFailType);
void* allocThrow(size_t bytes) {
return this->alloc(bytes, kThrow_AllocFailType);
}
/** Call this to unalloc the most-recently allocated ptr by alloc(). On
success, the number of bytes freed is returned, or 0 if the block could
not be unallocated. This is a hint to the underlying allocator that
the previous allocation may be reused, but the implementation is free
to ignore this call (and return 0).
*/
size_t unalloc(void* ptr);
size_t totalCapacity() const { return fTotalCapacity; }
size_t totalUsed() const { return fTotalUsed; }
SkDEBUGCODE(int blockCount() const { return fBlockCount; })
SkDEBUGCODE(size_t totalLost() const { return fTotalLost; })
/**
* Returns true if the specified address is within one of the chunks, and
* has at least 1-byte following the address (i.e. if addr points to the
* end of a chunk, then contains() will return false).
*/
bool contains(const void* addr) const;
private:
struct Block;
Block* fBlock;
size_t fMinSize;
size_t fChunkSize;
size_t fTotalCapacity;
size_t fTotalUsed; // will be <= fTotalCapacity
SkDEBUGCODE(int fBlockCount;)
SkDEBUGCODE(size_t fTotalLost;) // will be <= fTotalCapacity
Block* newBlock(size_t bytes, AllocFailType ftype);
Block* addBlockIfNecessary(size_t bytes, AllocFailType ftype);
SkDEBUGCODE(void validate();)
};
#endif