full_update_generator.cc revision e9f9661e99917c9b33e10fb6c4f10979b13f572b 
1//
2// Copyright (C) 2012 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 "update_engine/payload_generator/full_update_generator.h"
18
19#include <fcntl.h>
20#include <inttypes.h>
21
22#include <algorithm>
23#include <deque>
24#include <memory>
25
26#include <base/format_macros.h>
27#include <base/strings/string_util.h>
28#include <base/strings/stringprintf.h>
29#include <base/synchronization/lock.h>
30#include <base/threading/simple_thread.h>
31#include <brillo/secure_blob.h>
32
33#include "update_engine/common/utils.h"
34#include "update_engine/payload_generator/delta_diff_utils.h"
35
36using std::vector;
37
38namespace chromeos_update_engine {
39
40namespace {
41
42const size_t kDefaultFullChunkSize = 1024 * 1024;  // 1 MiB
43
44// This class encapsulates a full update chunk processing thread work. The
45// processor reads a chunk of data from the input file descriptor and compresses
46// it. The processor will destroy itself when the work is done.
47class ChunkProcessor : public base::DelegateSimpleThread::Delegate {
48 public:
49  // Read a chunk of |size| bytes from |fd| starting at offset |offset|.
50  ChunkProcessor(const PayloadVersion& version,
51                 int fd,
52                 off_t offset,
53                 size_t size,
54                 BlobFileWriter* blob_file,
55                 AnnotatedOperation* aop)
56      : version_(version),
57        fd_(fd),
58        offset_(offset),
59        size_(size),
60        blob_file_(blob_file),
61        aop_(aop) {}
62  // We use a default move constructor since all the data members are POD types.
63  ChunkProcessor(ChunkProcessor&&) = default;
64  ~ChunkProcessor() override = default;
65
66  // Overrides DelegateSimpleThread::Delegate.
67  // Run() handles the read from |fd| in a thread-safe way, and stores the
68  // new operation to generate the region starting at |offset| of size |size|
69  // in the output operation |aop|. The associated blob data is stored in
70  // |blob_fd| and |blob_file_size| is updated.
71  void Run() override;
72
73 private:
74  bool ProcessChunk();
75
76  // Work parameters.
77  const PayloadVersion& version_;
78  int fd_;
79  off_t offset_;
80  size_t size_;
81  BlobFileWriter* blob_file_;
82  AnnotatedOperation* aop_;
83
84  DISALLOW_COPY_AND_ASSIGN(ChunkProcessor);
85};
86
87void ChunkProcessor::Run() {
88  if (!ProcessChunk()) {
89    LOG(ERROR) << "Error processing region at " << offset_ << " of size "
90               << size_;
91  }
92}
93
94bool ChunkProcessor::ProcessChunk() {
95  brillo::Blob buffer_in_(size_);
96  brillo::Blob op_blob;
97  ssize_t bytes_read = -1;
98  TEST_AND_RETURN_FALSE(utils::PReadAll(fd_,
99                                        buffer_in_.data(),
100                                        buffer_in_.size(),
101                                        offset_,
102                                        &bytes_read));
103  TEST_AND_RETURN_FALSE(bytes_read == static_cast<ssize_t>(size_));
104
105  InstallOperation_Type op_type;
106  TEST_AND_RETURN_FALSE(diff_utils::GenerateBestFullOperation(
107      buffer_in_, version_, &op_blob, &op_type));
108
109  aop_->op.set_type(op_type);
110  TEST_AND_RETURN_FALSE(aop_->SetOperationBlob(op_blob, blob_file_));
111  return true;
112}
113
114}  // namespace
115
116bool FullUpdateGenerator::GenerateOperations(
117    const PayloadGenerationConfig& config,
118    const PartitionConfig& old_part,
119    const PartitionConfig& new_part,
120    BlobFileWriter* blob_file,
121    vector<AnnotatedOperation>* aops) {
122  TEST_AND_RETURN_FALSE(new_part.ValidateExists());
123
124  // FullUpdateGenerator requires a positive chunk_size, otherwise there will
125  // be only one operation with the whole partition which should not be allowed.
126  // For performance reasons, we force a small default hard limit of 1 MiB. This
127  // limit can be changed in the config, and we will use the smaller of the two
128  // soft/hard limits.
129  size_t full_chunk_size;
130  if (config.hard_chunk_size >= 0) {
131    full_chunk_size = std::min(static_cast<size_t>(config.hard_chunk_size),
132                               config.soft_chunk_size);
133  } else {
134    full_chunk_size = std::min(kDefaultFullChunkSize, config.soft_chunk_size);
135    LOG(INFO) << "No chunk_size provided, using the default chunk_size for the "
136              << "full operations: " << full_chunk_size << " bytes.";
137  }
138  TEST_AND_RETURN_FALSE(full_chunk_size > 0);
139  TEST_AND_RETURN_FALSE(full_chunk_size % config.block_size == 0);
140
141  size_t chunk_blocks = full_chunk_size / config.block_size;
142  size_t max_threads = diff_utils::GetMaxThreads();
143  LOG(INFO) << "Compressing partition " << new_part.name
144            << " from " << new_part.path << " splitting in chunks of "
145            << chunk_blocks << " blocks (" << config.block_size
146            << " bytes each) using " << max_threads << " threads";
147
148  int in_fd = open(new_part.path.c_str(), O_RDONLY, 0);
149  TEST_AND_RETURN_FALSE(in_fd >= 0);
150  ScopedFdCloser in_fd_closer(&in_fd);
151
152  // We potentially have all the ChunkProcessors in memory but only
153  // |max_threads| will actually hold a block in memory while we process.
154  size_t partition_blocks = new_part.size / config.block_size;
155  size_t num_chunks = (partition_blocks + chunk_blocks - 1) / chunk_blocks;
156  aops->resize(num_chunks);
157  vector<ChunkProcessor> chunk_processors;
158  chunk_processors.reserve(num_chunks);
159  blob_file->SetTotalBlobs(num_chunks);
160
161  for (size_t i = 0; i < num_chunks; ++i) {
162    size_t start_block = i * chunk_blocks;
163    // The last chunk could be smaller.
164    size_t num_blocks = std::min(chunk_blocks,
165                                 partition_blocks - i * chunk_blocks);
166
167    // Preset all the static information about the operations. The
168    // ChunkProcessor will set the rest.
169    AnnotatedOperation* aop = aops->data() + i;
170    aop->name = base::StringPrintf("<%s-operation-%" PRIuS ">",
171                                   new_part.name.c_str(), i);
172    Extent* dst_extent = aop->op.add_dst_extents();
173    dst_extent->set_start_block(start_block);
174    dst_extent->set_num_blocks(num_blocks);
175
176    chunk_processors.emplace_back(
177        config.version,
178        in_fd,
179        static_cast<off_t>(start_block) * config.block_size,
180        num_blocks * config.block_size,
181        blob_file,
182        aop);
183  }
184
185  // Thread pool used for worker threads.
186  base::DelegateSimpleThreadPool thread_pool("full-update-generator",
187                                             max_threads);
188  thread_pool.Start();
189  for (ChunkProcessor& processor : chunk_processors)
190    thread_pool.AddWork(&processor);
191  thread_pool.JoinAll();
192
193  // All the work done, disable logging.
194  blob_file->SetTotalBlobs(0);
195
196  // All the operations must have a type set at this point. Otherwise, a
197  // ChunkProcessor failed to complete.
198  for (const AnnotatedOperation& aop : *aops) {
199    if (!aop.op.has_type())
200      return false;
201  }
202  return true;
203}
204
205}  // namespace chromeos_update_engine
206