payload_generation_config.h revision 625406cee9a90ac2ed895f480286b7f0e8497f38 
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 UPDATE_ENGINE_PAYLOAD_GENERATOR_PAYLOAD_GENERATION_CONFIG_H_
18#define UPDATE_ENGINE_PAYLOAD_GENERATOR_PAYLOAD_GENERATION_CONFIG_H_
19
20#include <cstddef>
21
22#include <memory>
23#include <string>
24#include <vector>
25
26#include "update_engine/payload_constants.h"
27#include "update_engine/payload_generator/filesystem_interface.h"
28#include "update_engine/update_metadata.pb.h"
29
30namespace chromeos_update_engine {
31
32struct PartitionConfig {
33  explicit PartitionConfig(std::string name) : name(name) {}
34
35  // Returns whether the PartitionConfig is not an empty image and all the
36  // fields are set correctly to a valid image file.
37  bool ValidateExists() const;
38
39  // Open then filesystem stored in this partition and stores it in
40  // |fs_interface|. Returns whether opening the filesystem worked.
41  bool OpenFilesystem();
42
43  // The path to the partition file. This can be a regular file or a block
44  // device such as a loop device.
45  std::string path;
46
47  // The size of the data in |path|. If rootfs verification is used (verity)
48  // this value should match the size of the verity device for the rootfs, and
49  // the size of the whole kernel. This value could be smaller than the
50  // partition and is the size of the data update_engine assumes verified for
51  // the source image, and the size of that data it should generate for the
52  // target image.
53  uint64_t size = 0;
54
55  // The FilesystemInterface implementation used to access this partition's
56  // files.
57  std::unique_ptr<FilesystemInterface> fs_interface;
58
59  std::string name;
60};
61
62// The ImageConfig struct describes a pair of binaries kernel and rootfs and the
63// metadata associated with the image they are part of, like build number, size,
64// etc.
65struct ImageConfig {
66  // Returns whether the ImageConfig is an empty image.
67  bool ValidateIsEmpty() const;
68
69  // Load |rootfs_size| and |kernel.size| from the respective image files. For
70  // the kernel, the whole |kernel.path| file is assumed. For the rootfs, the
71  // size is detected from the filesystem.
72  // Returns whether the image size was properly detected.
73  bool LoadImageSize();
74
75  // Returns whether the |image_info| field is empty.
76  bool ImageInfoIsEmpty() const;
77
78  // The ImageInfo message defined in the update_metadata.proto file describes
79  // the metadata of the image.
80  ImageInfo image_info;
81
82  // The updated partitions.
83  PartitionConfig rootfs = PartitionConfig{kLegacyPartitionNameRoot};
84  PartitionConfig kernel = PartitionConfig{kLegacyPartitionNameKernel};
85};
86
87// The PayloadGenerationConfig struct encapsulates all the configuration to
88// build the requested payload. This includes information about the old and new
89// image as well as the restrictions applied to the payload (like minor-version
90// and full/delta payload).
91struct PayloadGenerationConfig {
92  // Returns whether the PayloadGenerationConfig is valid.
93  bool Validate() const;
94
95  // Image information about the new image that's the target of this payload.
96  ImageConfig target;
97
98  // Image information pertaining the old image, if any. This is only valid
99  // if is_full is false, so we are requested a delta payload.
100  ImageConfig source;
101
102  // Wheter the requested payload is a delta payload.
103  bool is_delta = false;
104
105  // The major_version of the requested payload.
106  uint64_t major_version;
107
108  // The minor_version of the requested payload.
109  uint32_t minor_version;
110
111  // The size of the rootfs partition, that not necessarily is the same as the
112  // filesystem in either source or target version, since there is some space
113  // after the partition used to store the verity hashes and or the bootcache.
114  uint64_t rootfs_partition_size = 0;
115
116  // The |hard_chunk_size| is the maximum size that a single operation should
117  // write in the destination. Operations bigger than chunk_size should be
118  // split. A value of -1 means no hard chunk size limit. A very low limit
119  // means more operations, and less of a chance to reuse the data.
120  ssize_t hard_chunk_size = -1;
121
122  // The |soft_chunk_size| is the preferred chunk size to use when there's no
123  // significant impact to the operations. For example, REPLACE, MOVE and
124  // SOURCE_COPY operations are not significantly impacted by the chunk size,
125  // except for a few bytes overhead in the manifest to describe extra
126  // operations. On the other hand, splitting BSDIFF operations impacts the
127  // payload size since it is not possible to use the redundancy *between*
128  // chunks.
129  size_t soft_chunk_size = 2 * 1024 * 1024;
130
131  // TODO(deymo): Remove the block_size member and maybe replace it with a
132  // minimum alignment size for blocks (if needed). Algorithms should be able to
133  // pick the block_size they want, but for now only 4 KiB is supported.
134
135  // The block size used for all the operations in the manifest.
136  size_t block_size = 4096;
137};
138
139}  // namespace chromeos_update_engine
140
141#endif  // UPDATE_ENGINE_PAYLOAD_GENERATOR_PAYLOAD_GENERATION_CONFIG_H_
142