delta_diff_utils.h revision a12ee11c78ac6d7c2605921a4006b6a7416e0c35 
1// Copyright 2015 The Chromium OS Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef UPDATE_ENGINE_PAYLOAD_GENERATOR_DELTA_DIFF_UTILS_H_
6#define UPDATE_ENGINE_PAYLOAD_GENERATOR_DELTA_DIFF_UTILS_H_
7
8#include <string>
9#include <vector>
10
11#include <chromeos/secure_blob.h>
12
13#include "update_engine/payload_generator/annotated_operation.h"
14#include "update_engine/payload_generator/extent_ranges.h"
15#include "update_engine/payload_generator/payload_generation_config.h"
16#include "update_engine/update_metadata.pb.h"
17
18namespace chromeos_update_engine {
19
20namespace diff_utils {
21
22// Create operations in |aops| to produce all the blocks in the |new_part|
23// partition using the filesystem opened in that PartitionConfig.
24// It uses the files reported by the filesystem in |old_part| and the data
25// blocks in that partition (if available) to determine the best way to compress
26// the new files (REPLACE, REPLACE_BZ, COPY, BSDIFF) and writes any necessary
27// data to the end of |data_fd| updating |data_file_size| accordingly.
28// |hard_chunk_blocks| and |soft_chunk_blocks| are the hard and soft chunk
29// limits in number of blocks respectively. The soft chunk limit is used to
30// split MOVE and SOURCE_COPY operations and REPLACE_BZ of zeroed blocks, while
31// the hard limit is used to split a file when generating other operations. A
32// value of -1 in |hard_chunk_blocks| means whole files.
33bool DeltaReadPartition(std::vector<AnnotatedOperation>* aops,
34                        const PartitionConfig& old_part,
35                        const PartitionConfig& new_part,
36                        ssize_t hard_chunk_blocks,
37                        size_t soft_chunk_blocks,
38                        BlobFileWriter* blob_file,
39                        bool src_ops_allowed);
40
41// Create operations in |aops| for identical blocks that moved around in the old
42// and new partition and also handle zeroed blocks. The old and new partition
43// are stored in the |old_part| and |new_part| files and have |old_num_blocks|
44// and |new_num_blocks| respectively. The maximum operation size is
45// |chunk_blocks| blocks, or unlimited if |chunk_blocks| is -1. The blobs of the
46// produced operations are stored in the |data_fd| file whose size is updated
47// in the value pointed by |data_file_size|.
48// The collections |old_visited_blocks| and |new_visited_blocks| state what
49// blocks already have operations reading or writing them and only operations
50// for unvisited blocks are produced by this function updating both collections
51// with the used blocks.
52bool DeltaMovedAndZeroBlocks(std::vector<AnnotatedOperation>* aops,
53                             const std::string& old_part,
54                             const std::string& new_part,
55                             size_t old_num_blocks,
56                             size_t new_num_blocks,
57                             ssize_t chunk_blocks,
58                             bool src_ops_allowed,
59                             BlobFileWriter* blob_file,
60                             ExtentRanges* old_visited_blocks,
61                             ExtentRanges* new_visited_blocks);
62
63// For a given file |name| append operations to |aops| to produce it in the
64// |new_part|. The file will be split in chunks of |chunk_blocks| blocks each
65// or treated as a single chunk if |chunk_blocks| is -1. The file data is
66// stored in |new_part| in the blocks described by |new_extents| and, if it
67// exists, the old version exists in |old_part| in the blocks described by
68// |old_extents|. The operations added to |aops| reference the data blob
69// in the file |data_fd|, which has length *data_file_size. *data_file_size is
70// updated appropriately. Returns true on success.
71bool DeltaReadFile(std::vector<AnnotatedOperation>* aops,
72                   const std::string& old_part,
73                   const std::string& new_part,
74                   const std::vector<Extent>& old_extents,
75                   const std::vector<Extent>& new_extents,
76                   const std::string& name,
77                   ssize_t chunk_blocks,
78                   BlobFileWriter* blob_file,
79                   bool src_ops_allowed);
80
81// Reads the blocks |old_extents| from |old_part| (if it exists) and the
82// |new_extents| from |new_part| and determines the smallest way to encode
83// this |new_extents| for the diff. It stores necessary data in |out_data| and
84// fills in |out_op|. If there's no change in old and new files, it creates a
85// MOVE operation. If there is a change, the smallest of REPLACE, REPLACE_BZ,
86// or BSDIFF wins. |new_extents| must not be empty.
87// If |src_ops_allowed| is true, it will emit SOURCE_COPY and SOURCE_BSDIFF
88// operations instead of MOVE and BSDIFF, respectively.
89// Returns true on success.
90bool ReadExtentsToDiff(const std::string& old_part,
91                       const std::string& new_part,
92                       const std::vector<Extent>& old_extents,
93                       const std::vector<Extent>& new_extents,
94                       bool bsdiff_allowed,
95                       chromeos::Blob* out_data,
96                       InstallOperation* out_op,
97                       bool src_ops_allowed);
98
99// Runs the bsdiff tool on two files and returns the resulting delta in
100// |out|. Returns true on success.
101bool BsdiffFiles(const std::string& old_file,
102                 const std::string& new_file,
103                 chromeos::Blob* out);
104
105// Returns true if |op| is a no-op operation that doesn't do any useful work
106// (e.g., a move operation that copies blocks onto themselves).
107bool IsNoopOperation(const InstallOperation& op);
108
109// Filters all the operations that are no-op, maintaining the relative order
110// of the rest of the operations.
111void FilterNoopOperations(std::vector<AnnotatedOperation>* ops);
112
113bool InitializePartitionInfo(const PartitionConfig& partition,
114                             PartitionInfo* info);
115
116// Compare two AnnotatedOperations by the start block of the first Extent in
117// their destination extents.
118bool CompareAopsByDestination(AnnotatedOperation first_aop,
119                              AnnotatedOperation second_aop);
120
121}  // namespace diff_utils
122
123}  // namespace chromeos_update_engine
124
125#endif  // UPDATE_ENGINE_PAYLOAD_GENERATOR_DELTA_DIFF_UTILS_H_
126