delta_diff_utils.h revision 20bdc70e540e021c4a26553dfdbfd2fabe8ea432 
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_DELTA_DIFF_UTILS_H_
18#define UPDATE_ENGINE_PAYLOAD_GENERATOR_DELTA_DIFF_UTILS_H_
19
20#include <string>
21#include <vector>
22
23#include <brillo/secure_blob.h>
24
25#include "update_engine/payload_generator/annotated_operation.h"
26#include "update_engine/payload_generator/extent_ranges.h"
27#include "update_engine/payload_generator/payload_generation_config.h"
28#include "update_engine/update_metadata.pb.h"
29
30namespace chromeos_update_engine {
31
32namespace diff_utils {
33
34// Create operations in |aops| to produce all the blocks in the |new_part|
35// partition using the filesystem opened in that PartitionConfig.
36// It uses the files reported by the filesystem in |old_part| and the data
37// blocks in that partition (if available) to determine the best way to compress
38// the new files (REPLACE, REPLACE_BZ, COPY, BSDIFF) and writes any necessary
39// data to |blob_file|. |hard_chunk_blocks| and |soft_chunk_blocks| are the hard
40// and soft chunk limits in number of blocks respectively. The soft chunk limit
41// is used to split MOVE and SOURCE_COPY operations and REPLACE_BZ of zeroed
42// blocks, while the hard limit is used to split a file when generating other
43// operations. A value of -1 in |hard_chunk_blocks| means whole files.
44bool DeltaReadPartition(std::vector<AnnotatedOperation>* aops,
45                        const PartitionConfig& old_part,
46                        const PartitionConfig& new_part,
47                        ssize_t hard_chunk_blocks,
48                        size_t soft_chunk_blocks,
49                        const PayloadVersion& version,
50                        BlobFileWriter* blob_file);
51
52// Create operations in |aops| for identical blocks that moved around in the old
53// and new partition and also handle zeroed blocks. The old and new partition
54// are stored in the |old_part| and |new_part| files and have |old_num_blocks|
55// and |new_num_blocks| respectively. The maximum operation size is
56// |chunk_blocks| blocks, or unlimited if |chunk_blocks| is -1. The blobs of the
57// produced operations are stored in the |blob_file|.
58// The collections |old_visited_blocks| and |new_visited_blocks| state what
59// blocks already have operations reading or writing them and only operations
60// for unvisited blocks are produced by this function updating both collections
61// with the used blocks.
62bool DeltaMovedAndZeroBlocks(std::vector<AnnotatedOperation>* aops,
63                             const std::string& old_part,
64                             const std::string& new_part,
65                             size_t old_num_blocks,
66                             size_t new_num_blocks,
67                             ssize_t chunk_blocks,
68                             const PayloadVersion& version,
69                             BlobFileWriter* blob_file,
70                             ExtentRanges* old_visited_blocks,
71                             ExtentRanges* new_visited_blocks);
72
73// For a given file |name| append operations to |aops| to produce it in the
74// |new_part|. The file will be split in chunks of |chunk_blocks| blocks each
75// or treated as a single chunk if |chunk_blocks| is -1. The file data is
76// stored in |new_part| in the blocks described by |new_extents| and, if it
77// exists, the old version exists in |old_part| in the blocks described by
78// |old_extents|. The operations added to |aops| reference the data blob
79// in the |blob_file|. Returns true on success.
80bool DeltaReadFile(std::vector<AnnotatedOperation>* aops,
81                   const std::string& old_part,
82                   const std::string& new_part,
83                   const std::vector<Extent>& old_extents,
84                   const std::vector<Extent>& new_extents,
85                   const std::string& name,
86                   ssize_t chunk_blocks,
87                   const PayloadVersion& version,
88                   BlobFileWriter* blob_file);
89
90// Reads the blocks |old_extents| from |old_part| (if it exists) and the
91// |new_extents| from |new_part| and determines the smallest way to encode
92// this |new_extents| for the diff. It stores necessary data in |out_data| and
93// fills in |out_op|. If there's no change in old and new files, it creates a
94// MOVE or SOURCE_COPY operation. If there is a change, the smallest of the
95// operations allowed in the given |version| (REPLACE, REPLACE_BZ, BSDIFF,
96// SOURCE_BSDIFF or IMGDIFF) wins.
97// |new_extents| must not be empty. Returns true on success.
98bool ReadExtentsToDiff(const std::string& old_part,
99                       const std::string& new_part,
100                       const std::vector<Extent>& old_extents,
101                       const std::vector<Extent>& new_extents,
102                       const PayloadVersion& version,
103                       brillo::Blob* out_data,
104                       InstallOperation* out_op);
105
106// Runs the bsdiff or imgdiff tool in |diff_path| on two files and returns the
107// resulting delta in |out|. Returns true on success.
108bool DiffFiles(const std::string& diff_path,
109               const std::string& old_file,
110               const std::string& new_file,
111               brillo::Blob* out);
112
113// Generates the best allowed full operation to produce |new_data|. The allowed
114// operations are based on |payload_version|. The operation blob will be stored
115// in |out_blob| and the resulting operation type in |out_type|. Returns whether
116// a valid full operation was generated.
117bool GenerateBestFullOperation(const brillo::Blob& new_data,
118                               const PayloadVersion& version,
119                               brillo::Blob* out_blob,
120                               InstallOperation_Type* out_type);
121
122// Returns whether op_type is one of the REPLACE full operations.
123bool IsAReplaceOperation(InstallOperation_Type op_type);
124
125// Returns true if |op| is a no-op operation that doesn't do any useful work
126// (e.g., a move operation that copies blocks onto themselves).
127bool IsNoopOperation(const InstallOperation& op);
128
129// Filters all the operations that are no-op, maintaining the relative order
130// of the rest of the operations.
131void FilterNoopOperations(std::vector<AnnotatedOperation>* ops);
132
133bool InitializePartitionInfo(const PartitionConfig& partition,
134                             PartitionInfo* info);
135
136// Compare two AnnotatedOperations by the start block of the first Extent in
137// their destination extents.
138bool CompareAopsByDestination(AnnotatedOperation first_aop,
139                              AnnotatedOperation second_aop);
140
141// Returns whether the filesystem is an ext[234] filesystem. In case of failure,
142// such as if the file |device| doesn't exists or can't be read, it returns
143// false.
144bool IsExtFilesystem(const std::string& device);
145
146}  // namespace diff_utils
147
148}  // namespace chromeos_update_engine
149
150#endif  // UPDATE_ENGINE_PAYLOAD_GENERATOR_DELTA_DIFF_UTILS_H_
151