1 // Copyright 2020 The Pigweed Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not 4 // use this file except in compliance with the License. You may obtain a copy of 5 // the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12 // License for the specific language governing permissions and limitations under 13 // the License. 14 #pragma once 15 16 #include <cstddef> 17 #include <span> 18 19 #include "pw_bytes/span.h" 20 #include "pw_status/status.h" 21 #include "pw_status/status_with_size.h" 22 #include "pw_stream/stream.h" 23 24 namespace pw::stream { 25 26 // Stream writer which quietly drops all of the data, similar to /dev/null. 27 class NullWriter final : public Writer { 28 private: DoWrite(ConstByteSpan)29 Status DoWrite(ConstByteSpan) final { return OkStatus(); } 30 }; 31 32 // Stream reader which never reads any bytes. Always returns OUT_OF_RANGE, which 33 // indicates there is no more data to read. 34 class NullReader final : public Reader { 35 private: DoRead(ByteSpan)36 StatusWithSize DoRead(ByteSpan) final { return StatusWithSize::OutOfRange(); } 37 }; 38 39 } // namespace pw::stream 40