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//
// Copyright (C) 2017 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/file_descriptor_utils.h"
#include <algorithm>
#include <base/logging.h>
#include "update_engine/common/hash_calculator.h"
#include "update_engine/common/utils.h"
#include "update_engine/payload_consumer/extent_writer.h"
using google::protobuf::RepeatedPtrField;
using std::min;
namespace chromeos_update_engine {
namespace {
// Size of the buffer used to copy blocks.
const int kMaxCopyBufferSize = 1024 * 1024;
// Return the total number of blocks in the passed |extents| list.
uint64_t GetBlockCount(const RepeatedPtrField<Extent>& extents) {
uint64_t sum = 0;
for (const Extent& ext : extents) {
sum += ext.num_blocks();
}
return sum;
}
} // namespace
namespace fd_utils {
bool CopyAndHashExtents(FileDescriptorPtr source,
const RepeatedPtrField<Extent>& src_extents,
FileDescriptorPtr target,
const RepeatedPtrField<Extent>& tgt_extents,
uint32_t block_size,
brillo::Blob* hash_out) {
HashCalculator source_hasher;
uint64_t buffer_blocks = kMaxCopyBufferSize / block_size;
// Ensure we copy at least one block at a time.
if (buffer_blocks < 1)
buffer_blocks = 1;
uint64_t total_blocks = GetBlockCount(src_extents);
TEST_AND_RETURN_FALSE(total_blocks == GetBlockCount(tgt_extents));
brillo::Blob buf(buffer_blocks * block_size);
DirectExtentWriter writer;
std::vector<Extent> vec_tgt_extents;
vec_tgt_extents.reserve(tgt_extents.size());
for (const auto& ext : tgt_extents) {
vec_tgt_extents.push_back(ext);
}
TEST_AND_RETURN_FALSE(writer.Init(target, vec_tgt_extents, block_size));
for (const Extent& src_ext : src_extents) {
for (uint64_t src_ext_block = 0; src_ext_block < src_ext.num_blocks();
src_ext_block += buffer_blocks) {
uint64_t iteration_blocks =
min(buffer_blocks,
static_cast<uint64_t>(src_ext.num_blocks() - src_ext_block));
uint64_t src_start_block = src_ext.start_block() + src_ext_block;
ssize_t bytes_read_this_iteration;
TEST_AND_RETURN_FALSE(utils::PReadAll(source,
buf.data(),
iteration_blocks * block_size,
src_start_block * block_size,
&bytes_read_this_iteration));
TEST_AND_RETURN_FALSE(
bytes_read_this_iteration ==
static_cast<ssize_t>(iteration_blocks * block_size));
TEST_AND_RETURN_FALSE(
writer.Write(buf.data(), iteration_blocks * block_size));
if (hash_out) {
TEST_AND_RETURN_FALSE(
source_hasher.Update(buf.data(), iteration_blocks * block_size));
}
}
}
TEST_AND_RETURN_FALSE(writer.End());
if (hash_out) {
TEST_AND_RETURN_FALSE(source_hasher.Finalize());
*hash_out = source_hasher.raw_hash();
}
return true;
}
} // namespace fd_utils
} // namespace chromeos_update_engine
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