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
|
/*
Copyright 2010 Google Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
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 GrAllocator_DEFINED
#define GrAllocator_DEFINED
#include "GrConfig.h"
#include "GrTArray.h"
class GrAllocator {
public:
virtual ~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, uint32_t itemsPerBlock, void* initialBlock) :
fBlocks(fBlockInitialStorage, NUM_INIT_BLOCK_PTRS),
fItemSize(itemSize),
fItemsPerBlock(itemsPerBlock),
fOwnFirstBlock(NULL == initialBlock),
fCount(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() {
uint32_t 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() {
uint32_t blockCount = GrMax((unsigned)1,
GrUIDivRoundUp(fCount, fItemsPerBlock));
for (uint32_t 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
*/
uint32_t 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[] (uint32_t i) {
GrAssert(i < fCount);
return (char*)fBlocks[i / fItemsPerBlock] +
fItemSize * (i % fItemsPerBlock);
}
/**
* access item by index.
*/
const void* operator[] (uint32_t i) const {
GrAssert(i < fCount);
return (const char*)fBlocks[i / fItemsPerBlock] +
fItemSize * (i % fItemsPerBlock);
}
private:
static const uint32_t NUM_INIT_BLOCK_PTRS = 8;
GrTArray<void*> fBlocks;
size_t fBlockSize;
char fBlockInitialStorage[NUM_INIT_BLOCK_PTRS*sizeof(void*)];
size_t fItemSize;
uint32_t fItemsPerBlock;
bool fOwnFirstBlock;
uint32_t fCount;
};
template <typename T>
class GrTAllocator {
private:
GrAllocator fAllocator;
public:
virtual ~GrTAllocator() {};
/**
* 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.
*/
GrTAllocator(uint32_t itemsPerBlock, void* initialBlock) :
fAllocator(sizeof(T), itemsPerBlock, initialBlock)
{}
/**
* Adds an item and returns it.
*
* @return the added item.
*/
T& push_back() {
void* item = fAllocator.push_back();
GrAssert(NULL != item);
new (item) T;
return *(T*)item;
}
/**
* removes all added items
*/
void reset() {
uint32_t c = fAllocator.count();
for (uint32_t i = 0; i < c; ++i) {
((T*)fAllocator[i])->~T();
}
fAllocator.reset();
}
/**
* count of items
*/
uint32_t 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[] (uint32_t i) {
return *(T*)(fAllocator[i]);
}
/**
* access item by index.
*/
const T& operator[] (uint32_t i) const {
return *(const T*)(fAllocator[i]);
}
};
#endif
|
