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// Copyright 2020 The Pigweed Authors
//
// 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
//
// https://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 "pw_kvs/alignment.h"
#include "pw_status/try.h"
namespace pw {
StatusWithSize AlignedWriter::Write(span<const std::byte> data) {
while (!data.empty()) {
size_t to_copy = std::min(write_size_ - bytes_in_buffer_, data.size());
std::memcpy(&buffer_[bytes_in_buffer_], data.data(), to_copy);
PW_TRY_WITH_SIZE(AddBytesToBuffer(to_copy));
data = data.subspan(to_copy);
}
return StatusWithSize(bytes_written_);
}
StatusWithSize AlignedWriter::Flush() {
Status status;
// If data remains in the buffer, pad it to the alignment size and flush the
// remaining data.
if (bytes_in_buffer_ != 0u) {
const size_t remaining_bytes = AlignUp(bytes_in_buffer_, alignment_bytes_);
std::memset(&buffer_[bytes_in_buffer_],
int(kPadByte),
remaining_bytes - bytes_in_buffer_);
status = output_.Write(buffer_, remaining_bytes).status();
bytes_written_ += remaining_bytes; // Include padding in the total.
bytes_in_buffer_ = 0;
}
const StatusWithSize result(status, bytes_written_);
bytes_written_ = 0;
return result;
}
StatusWithSize AlignedWriter::Write(Input& input, size_t size) {
while (size > 0u) {
const size_t to_read = std::min(write_size_ - bytes_in_buffer_, size);
StatusWithSize result = input.Read(buffer_ + bytes_in_buffer_, to_read);
if (!result.ok()) {
return StatusWithSize(result.status(), bytes_written_);
}
PW_TRY_WITH_SIZE(AddBytesToBuffer(to_read));
size -= result.size();
}
return StatusWithSize(bytes_written_);
}
StatusWithSize AlignedWriter::AddBytesToBuffer(size_t bytes_added) {
bytes_in_buffer_ += bytes_added;
// If the buffer is full, write it out.
if (bytes_in_buffer_ == write_size_) {
StatusWithSize result = output_.Write(buffer_, write_size_);
// Always use write_size_ for the bytes written. If there was an error
// assume the space was written or at least disturbed.
bytes_written_ += write_size_;
bytes_in_buffer_ = 0;
if (!result.ok()) {
return StatusWithSize(result.status(), bytes_written_);
}
}
return StatusWithSize(bytes_written_);
}
} // namespace pw
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