| // Copyright 2021 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_persistent_ram/persistent_buffer.h" |
| |
| #include "pw_bytes/span.h" |
| #include "pw_checksum/crc16_ccitt.h" |
| #include "pw_status/status.h" |
| |
| namespace pw::persistent_ram { |
| |
| Status PersistentBufferWriter::DoWrite(ConstByteSpan data) { |
| if (ConservativeWriteLimit() == 0) { |
| return Status::OutOfRange(); |
| } |
| if (ConservativeWriteLimit() < data.size_bytes()) { |
| return Status::ResourceExhausted(); |
| } |
| if (data.empty()) { |
| return OkStatus(); |
| } |
| |
| std::memcpy(buffer_.data() + size_, data.data(), data.size_bytes()); |
| |
| // Only checksum newly written data. |
| checksum_ = checksum::Crc16Ccitt::Calculate( |
| ByteSpan(buffer_.data() + size_, data.size_bytes()), checksum_); |
| size_ = size_ + data.size_bytes(); // += on a volatile is deprecated in C++20 |
| |
| return OkStatus(); |
| } |
| |
| } // namespace pw::persistent_ram |