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_FORMAT_BINARY_CHUNKWRITER_H
18 #define AAPT_FORMAT_BINARY_CHUNKWRITER_H
19 
20 #include "android-base/macros.h"
21 #include "androidfw/BigBuffer.h"
22 #include "androidfw/ResourceTypes.h"
23 #include "util/Util.h"
24 
25 namespace aapt {
26 
27 class ChunkWriter {
28  public:
ChunkWriter(android::BigBuffer * buffer)29   explicit inline ChunkWriter(android::BigBuffer* buffer) : buffer_(buffer) {
30   }
31   ChunkWriter(ChunkWriter&&) = default;
32   ChunkWriter& operator=(ChunkWriter&&) = default;
33 
34   template <typename T>
StartChunk(uint16_t type)35   inline T* StartChunk(uint16_t type) {
36     start_size_ = buffer_->size();
37     T* chunk = buffer_->NextBlock<T>();
38     header_ = &chunk->header;
39     header_->type = android::util::HostToDevice16(type);
40     header_->headerSize = android::util::HostToDevice16(sizeof(T));
41     return chunk;
42   }
43 
44   template <typename T>
45   inline T* NextBlock(size_t count = 1) {
46     return buffer_->NextBlock<T>(count);
47   }
48 
buffer()49   inline android::BigBuffer* buffer() {
50     return buffer_;
51   }
52 
chunk_header()53   inline android::ResChunk_header* chunk_header() {
54     return header_;
55   }
56 
size()57   inline size_t size() {
58     return buffer_->size() - start_size_;
59   }
60 
Finish()61   inline android::ResChunk_header* Finish() {
62     buffer_->Align4();
63     header_->size = android::util::HostToDevice32(buffer_->size() - start_size_);
64     return header_;
65   }
66 
67  private:
68   DISALLOW_COPY_AND_ASSIGN(ChunkWriter);
69 
70   android::BigBuffer* buffer_;
71   size_t start_size_ = 0;
72   android::ResChunk_header* header_ = nullptr;
73 };
74 
75 template <>
StartChunk(uint16_t type)76 inline android::ResChunk_header* ChunkWriter::StartChunk(uint16_t type) {
77   start_size_ = buffer_->size();
78   header_ = buffer_->NextBlock<android::ResChunk_header>();
79   header_->type = android::util::HostToDevice16(type);
80   header_->headerSize = android::util::HostToDevice16(sizeof(android::ResChunk_header));
81   return header_;
82 }
83 
84 }  // namespace aapt
85 
86 #endif /* AAPT_FORMAT_BINARY_CHUNKWRITER_H */
87