1 // Copyright 2021 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 <cstdint> 17 #include <limits> 18 19 #include "pw_status/status_with_size.h" 20 #include "pw_stream/stream.h" 21 22 namespace pw { 23 namespace varint { 24 25 /// @brief Decodes a variable-length integer (varint) from the current position 26 /// of a `pw::stream`. Reads a maximum of 10 bytes or `max_size`, whichever is 27 /// smaller. 28 /// 29 /// This method always returns the number of bytes read, even on error. 30 /// 31 /// @param reader The `pw::stream` to read from. 32 /// 33 /// @param output The integer to read into. If reading into a signed integer, 34 /// the value is 35 /// [ZigZag](https://protobuf.dev/programming-guides/encoding/#signed-ints)-decoded. 36 /// 37 /// @param max_size The maximum number of bytes to read. The upper limit is 10 38 /// bytes. 39 /// 40 /// @returns @rst 41 /// 42 /// .. pw-status-codes:: 43 /// 44 /// OK: The decoded value is placed in ``output``. 45 /// 46 /// OUT_OF_RANGE: No input is available, e.g. the stream is closed. 47 /// 48 /// DATA_LOSS: The decoded value is too large for ``output`` or is 49 /// incomplete, e.g. the input was exhausted after a partial varint was 50 /// read. 51 /// 52 /// @endrst 53 StatusWithSize Read(stream::Reader& reader, 54 int64_t* output, 55 size_t max_size = std::numeric_limits<size_t>::max()); 56 StatusWithSize Read(stream::Reader& reader, 57 uint64_t* output, 58 size_t max_size = std::numeric_limits<size_t>::max()); 59 60 } // namespace varint 61 } // namespace pw 62