aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/gpu/GrAllocator.h
blob: dc4c3de281a83ed0a75123c52f6bbcdada568952 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250

/*
 * Copyright 2010 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */



#ifndef GrAllocator_DEFINED
#define GrAllocator_DEFINED

#include "GrNoncopyable.h"
#include "GrConfig.h"
#include "SkTArray.h"

class GrAllocator : GrNoncopyable {
public:
    ~GrAllocator() {
        reset();
    }

    /**
     * Create an allocator
     *
     * @param   itemSize        the size of each item to allocate
     * @param   itemsPerBlock   the number of items to allocate at once
     * @param   initialBlock    optional memory to use for the first block.
     *                          Must be at least itemSize*itemsPerBlock sized.
     *                          Caller is responsible for freeing this memory.
     */
    GrAllocator(size_t itemSize, int itemsPerBlock, void* initialBlock) :
            fItemSize(itemSize),
            fItemsPerBlock(itemsPerBlock),
            fOwnFirstBlock(NULL == initialBlock),
            fCount(0) {
        GrAssert(itemsPerBlock > 0);
        fBlockSize = fItemSize * fItemsPerBlock;
        fBlocks.push_back() = initialBlock;
        GR_DEBUGCODE(if (!fOwnFirstBlock) {*((char*)initialBlock+fBlockSize-1)='a';} );
    }

    /**
     * Adds an item and returns pointer to it.
     *
     * @return pointer to the added item.
     */
    void* push_back() {
        int indexInBlock = fCount % fItemsPerBlock;
        // we always have at least one block
        if (0 == indexInBlock) {
            if (0 != fCount) {
                fBlocks.push_back() = GrMalloc(fBlockSize);
            } else if (fOwnFirstBlock) {
                fBlocks[0] = GrMalloc(fBlockSize);
            }
        }
        void* ret = (char*)fBlocks[fCount/fItemsPerBlock] +
                    fItemSize * indexInBlock;
        ++fCount;
        return ret;
    }

    /**
     * removes all added items
     */
    void reset() {
        int blockCount = GrMax((unsigned)1,
                               GrUIDivRoundUp(fCount, fItemsPerBlock));
        for (int i = 1; i < blockCount; ++i) {
            GrFree(fBlocks[i]);
        }
        if (fOwnFirstBlock) {
            GrFree(fBlocks[0]);
            fBlocks[0] = NULL;
        }
        fBlocks.pop_back_n(blockCount-1);
        fCount = 0;
    }

    /**
     * count of items
     */
    int count() const {
        return fCount;
    }

    /**
     * is the count 0
     */
    bool empty() const { return fCount == 0; }

    /**
     * access last item, only call if count() != 0
     */
    void* back() {
        GrAssert(fCount);
        return (*this)[fCount-1];
    }

    /**
     * access last item, only call if count() != 0
     */
    const void* back() const {
        GrAssert(fCount);
        return (*this)[fCount-1];
    }

    /**
     * access item by index.
     */
    void* operator[] (int i) {
        GrAssert(i >= 0 && i < fCount);
        return (char*)fBlocks[i / fItemsPerBlock] +
               fItemSize * (i % fItemsPerBlock);
    }

    /**
     * access item by index.
     */
    const void* operator[] (int i) const {
        GrAssert(i >= 0 && i < fCount);
        return (const char*)fBlocks[i / fItemsPerBlock] +
               fItemSize * (i % fItemsPerBlock);
    }

private:
    static const int NUM_INIT_BLOCK_PTRS = 8;

    SkSTArray<NUM_INIT_BLOCK_PTRS, void*>   fBlocks;
    size_t                                  fBlockSize;
    size_t                                  fItemSize;
    int                                     fItemsPerBlock;
    bool                                    fOwnFirstBlock;
    int                                     fCount;

    typedef GrNoncopyable INHERITED;
};

template <typename T>
class GrTAllocator : GrNoncopyable {

public:
    virtual ~GrTAllocator() { this->reset(); };

    /**
     * Create an allocator
     *
     * @param   itemsPerBlock   the number of items to allocate at once
     * @param   initialBlock    optional memory to use for the first block.
     *                          Must be at least size(T)*itemsPerBlock sized.
     *                          Caller is responsible for freeing this memory.
     */
    explicit GrTAllocator(int itemsPerBlock)
        : fAllocator(sizeof(T), itemsPerBlock, NULL) {}

    /**
     * Adds an item and returns it.
     *
     * @return the added item.
     */
    T& push_back() {
        void* item = fAllocator.push_back();
        GrAssert(NULL != item);
        SkNEW_PLACEMENT(item, T);
        return *(T*)item;
    }

    T& push_back(const T& t) {
        void* item = fAllocator.push_back();
        GrAssert(NULL != item);
        SkNEW_PLACEMENT_ARGS(item, T, (t));
        return *(T*)item;
    }

    /**
     * removes all added items
     */
    void reset() {
        int c = fAllocator.count();
        for (int i = 0; i < c; ++i) {
            ((T*)fAllocator[i])->~T();
        }
        fAllocator.reset();
    }

    /**
     * count of items
     */
    int count() const {
        return fAllocator.count();
    }

    /**
     * is the count 0
     */
    bool empty() const { return fAllocator.empty(); }

    /**
     * access last item, only call if count() != 0
     */
    T& back() {
        return *(T*)fAllocator.back();
    }

    /**
     * access last item, only call if count() != 0
     */
    const T& back() const {
        return *(const T*)fAllocator.back();
    }

    /**
     * access item by index.
     */
    T& operator[] (int i) {
        return *(T*)(fAllocator[i]);
    }

    /**
     * access item by index.
     */
    const T& operator[] (int i) const {
        return *(const T*)(fAllocator[i]);
    }

protected:
    GrTAllocator(int itemsPerBlock, void* initialBlock)
        : fAllocator(sizeof(T), itemsPerBlock, initialBlock) {
    }

private:
    GrAllocator fAllocator;
    typedef GrNoncopyable INHERITED;
};

template <int N, typename T> class GrSTAllocator : public GrTAllocator<T> {
private:
    typedef GrTAllocator<T> INHERITED;

public:
    GrSTAllocator() : INHERITED(N, fStorage.get()) {
    }

private:
    SkAlignedSTStorage<N, T> fStorage;
};

#endif