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
|
// Copyright 2018 The Android Open Source Project
//
// 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.
#pragma once
#include <inttypes.h>
#include <stddef.h>
#include <string.h>
namespace android {
namespace base {
class Stream;
// Class to create sub-allocations in an existing buffer. Similar interface to
// Pool, but underlying mechanism is different as it's difficult to combine
// same-size heaps in Pool with a preallocated buffer.
class SubAllocator {
public:
// |pageSize| determines both the alignment of pointers returned
// and the multiples of space occupied.
SubAllocator(
void* buffer,
uint64_t totalSize,
uint64_t pageSize);
// Memory is freed from the perspective of the user of
// SubAllocator, but the prealloced buffer is not freed.
~SubAllocator();
// Snapshotting
bool save(Stream* stream);
bool load(Stream* stream);
bool postLoad(void* postLoadBuffer);
// returns null if the allocation cannot be satisfied.
void* alloc(size_t wantedSize);
// returns true if |ptr| came from alloc(), false otherwise
bool free(void* ptr);
void freeAll();
uint64_t getOffset(void* ptr);
bool empty() const;
// Convenience function to allocate an array
// of objects of type T.
template <class T>
T* allocArray(size_t count) {
size_t bytes = sizeof(T) * count;
void* res = alloc(bytes);
return (T*) res;
}
char* strDup(const char* toCopy) {
size_t bytes = strlen(toCopy) + 1;
void* res = alloc(bytes);
memset(res, 0x0, bytes);
memcpy(res, toCopy, bytes);
return (char*)res;
}
char** strDupArray(const char* const* arrayToCopy, size_t count) {
char** res = allocArray<char*>(count);
for (size_t i = 0; i < count; i++) {
res[i] = strDup(arrayToCopy[i]);
}
return res;
}
void* dupArray(const void* buf, size_t bytes) {
void* res = alloc(bytes);
memcpy(res, buf, bytes);
return res;
}
private:
class Impl;
Impl* mImpl = nullptr;
};
} // namespace base
} // namespace android
|
