delta_diff_utils.h revision 3cd4df127c29eb90c0e203373edfbc9534c79169 
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#include <puffin/puffdiff.h>
25
26#include "update_engine/payload_generator/annotated_operation.h"
27#include "update_engine/payload_generator/extent_ranges.h"
28#include "update_engine/payload_generator/payload_generation_config.h"
29#include "update_engine/update_metadata.pb.h"
30
31namespace chromeos_update_engine {
32
33namespace diff_utils {
34
35// Create operations in |aops| to produce all the blocks in the |new_part|
36// partition using the filesystem opened in that PartitionConfig.
37// It uses the files reported by the filesystem in |old_part| and the data
38// blocks in that partition (if available) to determine the best way to compress
39// the new files (REPLACE, REPLACE_BZ, COPY, BSDIFF) and writes any necessary
40// data to |blob_file|. |hard_chunk_blocks| and |soft_chunk_blocks| are the hard
41// and soft chunk limits in number of blocks respectively. The soft chunk limit
42// is used to split MOVE and SOURCE_COPY operations and REPLACE_BZ of zeroed
43// blocks, while the hard limit is used to split a file when generating other
44// operations. A 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                        const PayloadVersion& version,
51                        BlobFileWriter* blob_file);
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 |blob_file|.
59// The collections |old_visited_blocks| and |new_visited_blocks| state what
60// blocks already have operations reading or writing them and only operations
61// for unvisited blocks are produced by this function updating both collections
62// with the used blocks.
63bool DeltaMovedAndZeroBlocks(std::vector<AnnotatedOperation>* aops,
64                             const std::string& old_part,
65                             const std::string& new_part,
66                             size_t old_num_blocks,
67                             size_t new_num_blocks,
68                             ssize_t chunk_blocks,
69                             const PayloadVersion& version,
70                             BlobFileWriter* blob_file,
71                             ExtentRanges* old_visited_blocks,
72                             ExtentRanges* new_visited_blocks);
73
74// For a given file |name| append operations to |aops| to produce it in the
75// |new_part|. The file will be split in chunks of |chunk_blocks| blocks each
76// or treated as a single chunk if |chunk_blocks| is -1. The file data is
77// stored in |new_part| in the blocks described by |new_extents| and, if it
78// exists, the old version exists in |old_part| in the blocks described by
79// |old_extents|. The operations added to |aops| reference the data blob
80// in the |blob_file|. |old_deflates| and |new_deflates| are all deflate
81// locations in |old_part| and |new_part|. Returns true on success.
82bool DeltaReadFile(std::vector<AnnotatedOperation>* aops,
83                   const std::string& old_part,
84                   const std::string& new_part,
85                   const std::vector<Extent>& old_extents,
86                   const std::vector<Extent>& new_extents,
87                   const std::vector<puffin::BitExtent>& old_deflates,
88                   const std::vector<puffin::BitExtent>& new_deflates,
89                   const std::string& name,
90                   ssize_t chunk_blocks,
91                   const PayloadVersion& version,
92                   BlobFileWriter* blob_file);
93
94// Reads the blocks |old_extents| from |old_part| (if it exists) and the
95// |new_extents| from |new_part| and determines the smallest way to encode
96// this |new_extents| for the diff. It stores necessary data in |out_data| and
97// fills in |out_op|. If there's no change in old and new files, it creates a
98// MOVE or SOURCE_COPY operation. If there is a change, the smallest of the
99// operations allowed in the given |version| (REPLACE, REPLACE_BZ, BSDIFF,
100// SOURCE_BSDIFF, or PUFFDIFF) wins.
101// |new_extents| must not be empty. |old_deflates| and |new_deflates| are all
102// the deflate locations in |old_part| and |new_part|. Returns true on success.
103bool ReadExtentsToDiff(const std::string& old_part,
104                       const std::string& new_part,
105                       const std::vector<Extent>& old_extents,
106                       const std::vector<Extent>& new_extents,
107                       const std::vector<puffin::BitExtent>& old_deflates,
108                       const std::vector<puffin::BitExtent>& new_deflates,
109                       const PayloadVersion& version,
110                       brillo::Blob* out_data,
111                       InstallOperation* out_op);
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 an operation with type |op_type| has no |src_extents|.
126bool IsNoSourceOperation(InstallOperation_Type op_type);
127
128// Returns true if |op| is a no-op operation that doesn't do any useful work
129// (e.g., a move operation that copies blocks onto themselves).
130bool IsNoopOperation(const InstallOperation& op);
131
132// Filters all the operations that are no-op, maintaining the relative order
133// of the rest of the operations.
134void FilterNoopOperations(std::vector<AnnotatedOperation>* ops);
135
136bool InitializePartitionInfo(const PartitionConfig& partition,
137                             PartitionInfo* info);
138
139// Compare two AnnotatedOperations by the start block of the first Extent in
140// their destination extents.
141bool CompareAopsByDestination(AnnotatedOperation first_aop,
142                              AnnotatedOperation second_aop);
143
144// Returns whether the filesystem is an ext[234] filesystem. In case of failure,
145// such as if the file |device| doesn't exists or can't be read, it returns
146// false.
147bool IsExtFilesystem(const std::string& device);
148
149// Returns the max number of threads to process the files(chunks) in parallel.
150size_t GetMaxThreads();
151
152}  // namespace diff_utils
153
154}  // namespace chromeos_update_engine
155
156#endif  // UPDATE_ENGINE_PAYLOAD_GENERATOR_DELTA_DIFF_UTILS_H_
157