| // 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_snapshot/uuid.h" |
| |
| #include <cstddef> |
| #include <span> |
| |
| #include "pw_bytes/span.h" |
| #include "pw_protobuf/decoder.h" |
| #include "pw_result/result.h" |
| #include "pw_snapshot_metadata_proto/snapshot_metadata.pwpb.h" |
| #include "pw_status/try.h" |
| |
| namespace pw::snapshot { |
| |
| using protobuf::Decoder; |
| |
| Result<ConstByteSpan> ReadUuidFromSnapshot(ConstByteSpan snapshot, |
| UuidSpan output) { |
| Decoder decoder(snapshot); |
| ConstByteSpan metadata; |
| while (decoder.Next().ok()) { |
| if (decoder.FieldNumber() == |
| static_cast<uint32_t>( |
| pw::snapshot::SnapshotBasicInfo::Fields::METADATA)) { |
| PW_TRY(decoder.ReadBytes(&metadata)); |
| break; |
| } |
| } |
| if (metadata.empty()) { |
| return Status::NotFound(); |
| } |
| |
| // Start to read from the metadata. |
| decoder.Reset(metadata); |
| ConstByteSpan snapshot_uuid; |
| while (decoder.Next().ok()) { |
| if (decoder.FieldNumber() == |
| static_cast<uint32_t>(pw::snapshot::Metadata::Fields::SNAPSHOT_UUID)) { |
| PW_TRY(decoder.ReadBytes(&snapshot_uuid)); |
| break; |
| } |
| } |
| if (snapshot_uuid.empty()) { |
| return Status::NotFound(); |
| } |
| if (snapshot_uuid.size_bytes() > output.size_bytes()) { |
| return Status::ResourceExhausted(); |
| } |
| |
| memcpy(output.data(), snapshot_uuid.data(), snapshot_uuid.size_bytes()); |
| return ConstByteSpan(output.first(snapshot_uuid.size_bytes())); |
| } |
| |
| } // namespace pw::snapshot |