delta_diff_utils.h revision aea4c1cea20dda7ae7e85fc8924a2d784f70d806 
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 <chromeos/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 the end of |data_fd| updating |data_file_size| accordingly.
40// |hard_chunk_blocks| and |soft_chunk_blocks| are the hard and soft chunk
41// limits in number of blocks respectively. The soft chunk limit is used to
42// split MOVE and SOURCE_COPY operations and REPLACE_BZ of zeroed blocks, while
43// the hard limit is used to split a file when generating other operations. A
44// value of -1 in |hard_chunk_blocks| means whole files.
45bool DeltaReadPartition(std::vector<AnnotatedOperation>* aops,
46                        const PartitionConfig& old_part,
47                        const PartitionConfig& new_part,
48                        ssize_t hard_chunk_blocks,
49                        size_t soft_chunk_blocks,
50                        BlobFileWriter* blob_file,
51                        bool src_ops_allowed);
52
53// Create operations in |aops| for identical blocks that moved around in the old
54// and new partition and also handle zeroed blocks. The old and new partition
55// are stored in the |old_part| and |new_part| files and have |old_num_blocks|
56// and |new_num_blocks| respectively. The maximum operation size is
57// |chunk_blocks| blocks, or unlimited if |chunk_blocks| is -1. The blobs of the
58// produced operations are stored in the |data_fd| file whose size is updated
59// in the value pointed by |data_file_size|.
60// The collections |old_visited_blocks| and |new_visited_blocks| state what
61// blocks already have operations reading or writing them and only operations
62// for unvisited blocks are produced by this function updating both collections
63// with the used blocks.
64bool DeltaMovedAndZeroBlocks(std::vector<AnnotatedOperation>* aops,
65                             const std::string& old_part,
66                             const std::string& new_part,
67                             size_t old_num_blocks,
68                             size_t new_num_blocks,
69                             ssize_t chunk_blocks,
70                             bool src_ops_allowed,
71                             BlobFileWriter* blob_file,
72                             ExtentRanges* old_visited_blocks,
73                             ExtentRanges* new_visited_blocks);
74
75// For a given file |name| append operations to |aops| to produce it in the
76// |new_part|. The file will be split in chunks of |chunk_blocks| blocks each
77// or treated as a single chunk if |chunk_blocks| is -1. The file data is
78// stored in |new_part| in the blocks described by |new_extents| and, if it
79// exists, the old version exists in |old_part| in the blocks described by
80// |old_extents|. The operations added to |aops| reference the data blob
81// in the file |data_fd|, which has length *data_file_size. *data_file_size is
82// updated appropriately. Returns true on success.
83bool DeltaReadFile(std::vector<AnnotatedOperation>* aops,
84                   const std::string& old_part,
85                   const std::string& new_part,
86                   const std::vector<Extent>& old_extents,
87                   const std::vector<Extent>& new_extents,
88                   const std::string& name,
89                   ssize_t chunk_blocks,
90                   BlobFileWriter* blob_file,
91                   bool src_ops_allowed);
92
93// Reads the blocks |old_extents| from |old_part| (if it exists) and the
94// |new_extents| from |new_part| and determines the smallest way to encode
95// this |new_extents| for the diff. It stores necessary data in |out_data| and
96// fills in |out_op|. If there's no change in old and new files, it creates a
97// MOVE operation. If there is a change, the smallest of REPLACE, REPLACE_BZ,
98// or BSDIFF wins. |new_extents| must not be empty.
99// If |src_ops_allowed| is true, it will emit SOURCE_COPY and SOURCE_BSDIFF
100// operations instead of MOVE and BSDIFF, respectively.
101// Returns true on success.
102bool ReadExtentsToDiff(const std::string& old_part,
103                       const std::string& new_part,
104                       const std::vector<Extent>& old_extents,
105                       const std::vector<Extent>& new_extents,
106                       bool bsdiff_allowed,
107                       chromeos::Blob* out_data,
108                       InstallOperation* out_op,
109                       bool src_ops_allowed);
110
111// Runs the bsdiff tool on two files and returns the resulting delta in
112// |out|. Returns true on success.
113bool BsdiffFiles(const std::string& old_file,
114                 const std::string& new_file,
115                 chromeos::Blob* out);
116
117// Returns true if |op| is a no-op operation that doesn't do any useful work
118// (e.g., a move operation that copies blocks onto themselves).
119bool IsNoopOperation(const InstallOperation& op);
120
121// Filters all the operations that are no-op, maintaining the relative order
122// of the rest of the operations.
123void FilterNoopOperations(std::vector<AnnotatedOperation>* ops);
124
125bool InitializePartitionInfo(const PartitionConfig& partition,
126                             PartitionInfo* info);
127
128// Compare two AnnotatedOperations by the start block of the first Extent in
129// their destination extents.
130bool CompareAopsByDestination(AnnotatedOperation first_aop,
131                              AnnotatedOperation second_aop);
132
133}  // namespace diff_utils
134
135}  // namespace chromeos_update_engine
136
137#endif  // UPDATE_ENGINE_PAYLOAD_GENERATOR_DELTA_DIFF_UTILS_H_
138