full_update_generator.cc revision 726aeca1c665910593761a1990ee50f22d98f53f 
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  if (!op_blob.empty()) {
111    TEST_AND_RETURN_FALSE(aop_->SetOperationBlob(op_blob, blob_file_));
112  }
113  return true;
114}
115
116}  // namespace
117
118bool FullUpdateGenerator::GenerateOperations(
119    const PayloadGenerationConfig& config,
120    const PartitionConfig& old_part,
121    const PartitionConfig& new_part,
122    BlobFileWriter* blob_file,
123    vector<AnnotatedOperation>* aops) {
124  TEST_AND_RETURN_FALSE(new_part.ValidateExists());
125
126  // FullUpdateGenerator requires a positive chunk_size, otherwise there will
127  // be only one operation with the whole partition which should not be allowed.
128  // For performance reasons, we force a small default hard limit of 1 MiB. This
129  // limit can be changed in the config, and we will use the smaller of the two
130  // soft/hard limits.
131  size_t full_chunk_size;
132  if (config.hard_chunk_size >= 0) {
133    full_chunk_size = std::min(static_cast<size_t>(config.hard_chunk_size),
134                               config.soft_chunk_size);
135  } else {
136    full_chunk_size = std::min(kDefaultFullChunkSize, config.soft_chunk_size);
137    LOG(INFO) << "No chunk_size provided, using the default chunk_size for the "
138              << "full operations: " << full_chunk_size << " bytes.";
139  }
140  TEST_AND_RETURN_FALSE(full_chunk_size > 0);
141  TEST_AND_RETURN_FALSE(full_chunk_size % config.block_size == 0);
142
143  size_t chunk_blocks = full_chunk_size / config.block_size;
144  size_t max_threads = std::max(sysconf(_SC_NPROCESSORS_ONLN), 4L);
145  LOG(INFO) << "Compressing partition " << new_part.name
146            << " from " << new_part.path << " splitting in chunks of "
147            << chunk_blocks << " blocks (" << config.block_size
148            << " bytes each) using " << max_threads << " threads";
149
150  int in_fd = open(new_part.path.c_str(), O_RDONLY, 0);
151  TEST_AND_RETURN_FALSE(in_fd >= 0);
152  ScopedFdCloser in_fd_closer(&in_fd);
153
154  // We potentially have all the ChunkProcessors in memory but only
155  // |max_threads| will actually hold a block in memory while we process.
156  size_t partition_blocks = new_part.size / config.block_size;
157  size_t num_chunks = (partition_blocks + chunk_blocks - 1) / chunk_blocks;
158  aops->resize(num_chunks);
159  vector<ChunkProcessor> chunk_processors;
160  chunk_processors.reserve(num_chunks);
161  blob_file->SetTotalBlobs(num_chunks);
162
163  for (size_t i = 0; i < num_chunks; ++i) {
164    size_t start_block = i * chunk_blocks;
165    // The last chunk could be smaller.
166    size_t num_blocks = std::min(chunk_blocks,
167                                 partition_blocks - i * chunk_blocks);
168
169    // Preset all the static information about the operations. The
170    // ChunkProcessor will set the rest.
171    AnnotatedOperation* aop = aops->data() + i;
172    aop->name = base::StringPrintf("<%s-operation-%" PRIuS ">",
173                                   new_part.name.c_str(), i);
174    Extent* dst_extent = aop->op.add_dst_extents();
175    dst_extent->set_start_block(start_block);
176    dst_extent->set_num_blocks(num_blocks);
177
178    chunk_processors.emplace_back(
179        config.version,
180        in_fd,
181        static_cast<off_t>(start_block) * config.block_size,
182        num_blocks * config.block_size,
183        blob_file,
184        aop);
185  }
186
187  // Thread pool used for worker threads.
188  base::DelegateSimpleThreadPool thread_pool("full-update-generator",
189                                             max_threads);
190  thread_pool.Start();
191  for (ChunkProcessor& processor : chunk_processors)
192    thread_pool.AddWork(&processor);
193  thread_pool.JoinAll();
194
195  // All the work done, disable logging.
196  blob_file->SetTotalBlobs(0);
197
198  // All the operations must have a type set at this point. Otherwise, a
199  // ChunkProcessor failed to complete.
200  for (const AnnotatedOperation& aop : *aops) {
201    if (!aop.op.has_type())
202      return false;
203  }
204  return true;
205}
206
207}  // namespace chromeos_update_engine
208