1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef AAPT_IO_DATA_H
18 #define AAPT_IO_DATA_H
19 
20 #include <utils/FileMap.h>
21 
22 #include <memory>
23 
24 namespace aapt {
25 namespace io {
26 
27 /**
28  * Interface for a block of contiguous memory. An instance of this interface owns the data.
29  */
30 class IData {
31 public:
32     virtual ~IData() = default;
33 
34     virtual const void* data() const = 0;
35     virtual size_t size() const = 0;
36 };
37 
38 /**
39  * Implementation of IData that exposes a memory mapped file. The mmapped file is owned by this
40  * object.
41  */
42 class MmappedData : public IData {
43 public:
MmappedData(android::FileMap && map)44     explicit MmappedData(android::FileMap&& map) : mMap(std::forward<android::FileMap>(map)) {
45     }
46 
data()47     const void* data() const override {
48         return mMap.getDataPtr();
49     }
50 
size()51     size_t size() const override {
52         return mMap.getDataLength();
53     }
54 
55 private:
56     android::FileMap mMap;
57 };
58 
59 /**
60  * Implementation of IData that exposes a block of memory that was malloc'ed (new'ed). The
61  * memory is owned by this object.
62  */
63 class MallocData : public IData {
64 public:
MallocData(std::unique_ptr<const uint8_t[]> data,size_t size)65     MallocData(std::unique_ptr<const uint8_t[]> data, size_t size) :
66             mData(std::move(data)), mSize(size) {
67     }
68 
data()69     const void* data() const override {
70         return mData.get();
71     }
72 
size()73     size_t size() const override {
74         return mSize;
75     }
76 
77 private:
78     std::unique_ptr<const uint8_t[]> mData;
79     size_t mSize;
80 };
81 
82 /**
83  * When mmap fails because the file has length 0, we use the EmptyData to simulate data of length 0.
84  */
85 class EmptyData : public IData {
86 public:
data()87     const void* data() const override {
88         static const uint8_t d = 0;
89         return &d;
90     }
91 
size()92     size_t size() const override {
93         return 0u;
94     }
95 };
96 
97 } // namespace io
98 } // namespace aapt
99 
100 #endif /* AAPT_IO_DATA_H */
101