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 #include "util/BigBuffer.h"
18 
19 #include <algorithm>
20 #include <memory>
21 #include <vector>
22 
23 #include "android-base/logging.h"
24 
25 namespace aapt {
26 
NextBlockImpl(size_t size)27 void* BigBuffer::NextBlockImpl(size_t size) {
28   if (!blocks_.empty()) {
29     Block& block = blocks_.back();
30     if (block.block_size_ - block.size >= size) {
31       void* out_buffer = block.buffer.get() + block.size;
32       block.size += size;
33       size_ += size;
34       return out_buffer;
35     }
36   }
37 
38   const size_t actual_size = std::max(block_size_, size);
39 
40   Block block = {};
41 
42   // Zero-allocate the block's buffer.
43   block.buffer = std::unique_ptr<uint8_t[]>(new uint8_t[actual_size]());
44   CHECK(block.buffer);
45 
46   block.size = size;
47   block.block_size_ = actual_size;
48 
49   blocks_.push_back(std::move(block));
50   size_ += size;
51   return blocks_.back().buffer.get();
52 }
53 
NextBlock(size_t * out_size)54 void* BigBuffer::NextBlock(size_t* out_size) {
55   if (!blocks_.empty()) {
56     Block& block = blocks_.back();
57     if (block.size != block.block_size_) {
58       void* out_buffer = block.buffer.get() + block.size;
59       size_t size = block.block_size_ - block.size;
60       block.size = block.block_size_;
61       size_ += size;
62       *out_size = size;
63       return out_buffer;
64     }
65   }
66 
67   // Zero-allocate the block's buffer.
68   Block block = {};
69   block.buffer = std::unique_ptr<uint8_t[]>(new uint8_t[block_size_]());
70   CHECK(block.buffer);
71   block.size = block_size_;
72   block.block_size_ = block_size_;
73   blocks_.push_back(std::move(block));
74   size_ += block_size_;
75   *out_size = block_size_;
76   return blocks_.back().buffer.get();
77 }
78 
to_string() const79 std::string BigBuffer::to_string() const {
80   std::string result;
81   for (const Block& block : blocks_) {
82     result.append(block.buffer.get(), block.buffer.get() + block.size);
83   }
84   return result;
85 }
86 
87 }  // namespace aapt
88