1 // Copyright 2021 The Android Open Source Project
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 #pragma once
15 
16 #include <inttypes.h>
17 #include <stddef.h>
18 #include <string.h>
19 
20 namespace gfxstream {
21 namespace guest {
22 
23 // A generic memory allocator interface which could be used to allocate
24 // a certain size of memory region, or memory region for arrays / strings.
25 // How the memory are recycled / freed is up to derived classes.
26 class Allocator {
27 public:
28     Allocator() = default;
29     virtual ~Allocator() = default;
30 
31     virtual void* alloc(size_t wantedSize) = 0;
32 
33     // Convenience function to allocate an array
34     // of objects of type T.
35     template <class T>
allocArray(size_t count)36     T* allocArray(size_t count) {
37         size_t bytes = sizeof(T) * count;
38         void* res = alloc(bytes);
39         return (T*)res;
40     }
41 
strDup(const char * toCopy)42     char* strDup(const char* toCopy) {
43         size_t bytes = strlen(toCopy) + 1;
44         void* res = alloc(bytes);
45         memset(res, 0x0, bytes);
46         memcpy(res, toCopy, bytes);
47         return (char*)res;
48     }
49 
strDupArray(const char * const * arrayToCopy,size_t count)50     char** strDupArray(const char* const* arrayToCopy, size_t count) {
51         char** res = allocArray<char*>(count);
52 
53         for (size_t i = 0; i < count; i++) {
54             res[i] = strDup(arrayToCopy[i]);
55         }
56 
57         return res;
58     }
59 
dupArray(const void * buf,size_t bytes)60     void* dupArray(const void* buf, size_t bytes) {
61         void* res = alloc(bytes);
62         memcpy(res, buf, bytes);
63         return res;
64     }
65 };
66 
67 }  // namespace base
68 }  // namespace android
69