1
2/*
3 * Copyright 2006 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#ifndef SkChunkAlloc_DEFINED
11#define SkChunkAlloc_DEFINED
12
13#include "SkTypes.h"
14
15class SkChunkAlloc : SkNoncopyable {
16public:
17    SkChunkAlloc(size_t minSize);
18    ~SkChunkAlloc();
19
20    /**
21     *  Free up all allocated blocks. This invalidates all returned
22     *  pointers.
23     */
24    void reset();
25
26    enum AllocFailType {
27        kReturnNil_AllocFailType,
28        kThrow_AllocFailType
29    };
30
31    void* alloc(size_t bytes, AllocFailType);
32    void* allocThrow(size_t bytes) {
33        return this->alloc(bytes, kThrow_AllocFailType);
34    }
35
36    /** Call this to unalloc the most-recently allocated ptr by alloc(). On
37        success, the number of bytes freed is returned, or 0 if the block could
38        not be unallocated. This is a hint to the underlying allocator that
39        the previous allocation may be reused, but the implementation is free
40        to ignore this call (and return 0).
41     */
42    size_t unalloc(void* ptr);
43
44    size_t totalCapacity() const { return fTotalCapacity; }
45    size_t totalUsed() const { return fTotalUsed; }
46    int blockCount() const { return fBlockCount; }
47
48    /**
49     *  Returns true if the specified address is within one of the chunks, and
50     *  has at least 1-byte following the address (i.e. if addr points to the
51     *  end of a chunk, then contains() will return false).
52     */
53    bool contains(const void* addr) const;
54
55private:
56    struct Block;
57
58    Block*  fBlock;
59    size_t  fMinSize;
60    size_t  fChunkSize;
61    size_t  fTotalCapacity;
62    size_t  fTotalUsed;     // will be <= fTotalCapacity
63    int     fBlockCount;
64
65    Block* newBlock(size_t bytes, AllocFailType ftype);
66};
67
68#endif
69