1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
|
//
// Copyright (C) 2020 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#include "update_engine/payload_consumer/snapshot_extent_writer.h"
#include <algorithm>
#include <cstdint>
#include <libsnapshot/cow_writer.h>
#include "update_engine/update_metadata.pb.h"
namespace chromeos_update_engine {
SnapshotExtentWriter::SnapshotExtentWriter(
android::snapshot::ICowWriter* cow_writer)
: cow_writer_(cow_writer) {
CHECK_NE(cow_writer, nullptr);
}
SnapshotExtentWriter::~SnapshotExtentWriter() {
CHECK(buffer_.empty()) << buffer_.size();
}
bool SnapshotExtentWriter::Init(
const google::protobuf::RepeatedPtrField<Extent>& extents,
uint32_t block_size) {
extents_ = extents;
cur_extent_idx_ = 0;
buffer_.clear();
buffer_.reserve(block_size);
block_size_ = block_size;
return true;
}
size_t SnapshotExtentWriter::ConsumeWithBuffer(const uint8_t* data,
size_t count) {
CHECK_LT(cur_extent_idx_, static_cast<size_t>(extents_.size()));
const auto& cur_extent = extents_[cur_extent_idx_];
const auto cur_extent_size = cur_extent.num_blocks() * block_size_;
if (buffer_.empty() && count >= cur_extent_size) {
if (!cow_writer_->AddRawBlocks(
cur_extent.start_block(), data, cur_extent_size)) {
LOG(ERROR) << "AddRawBlocks(" << cur_extent.start_block() << ", " << data
<< ", " << cur_extent_size << ") failed.";
// return value is expected to be greater than 0. Return 0 to signal error
// condition
return 0;
}
if (!next_extent()) {
CHECK_EQ(count, cur_extent_size)
<< "Exhausted all blocks, but still have " << count - cur_extent_size
<< " bytes left";
}
return cur_extent_size;
}
CHECK_LT(buffer_.size(), cur_extent_size)
<< "Data left in buffer should never be >= cur_extent_size, otherwise "
"we should have send that data to CowWriter. Buffer size: "
<< buffer_.size() << " current extent size: " << cur_extent_size;
size_t bytes_to_copy =
std::min<size_t>(count, cur_extent_size - buffer_.size());
CHECK_GT(bytes_to_copy, 0U);
buffer_.insert(buffer_.end(), data, data + bytes_to_copy);
CHECK_LE(buffer_.size(), cur_extent_size);
if (buffer_.size() == cur_extent_size) {
if (!cow_writer_->AddRawBlocks(
cur_extent.start_block(), buffer_.data(), buffer_.size())) {
LOG(ERROR) << "AddRawBlocks(" << cur_extent.start_block() << ", "
<< buffer_.data() << ", " << buffer_.size() << ") failed.";
return 0;
}
buffer_.clear();
if (!next_extent()) {
CHECK_EQ(count, bytes_to_copy) << "Exhausted all blocks, but still have "
<< count - bytes_to_copy << " bytes left";
}
}
return bytes_to_copy;
}
// Returns true on success.
// This will construct a COW_REPLACE operation and forward it to CowWriter. It
// is important that caller does not perform SOURCE_COPY operation on this
// class, otherwise raw data will be stored. Caller should find ways to use
// COW_COPY whenever possible.
bool SnapshotExtentWriter::Write(const void* bytes, size_t count) {
if (count == 0) {
return true;
}
CHECK_NE(extents_.size(), 0);
auto data = static_cast<const uint8_t*>(bytes);
while (count > 0) {
auto bytes_written = ConsumeWithBuffer(data, count);
TEST_AND_RETURN_FALSE(bytes_written > 0);
data += bytes_written;
count -= bytes_written;
}
return true;
}
bool SnapshotExtentWriter::next_extent() {
cur_extent_idx_++;
return cur_extent_idx_ < static_cast<size_t>(extents_.size());
}
} // namespace chromeos_update_engine
|
