brpc/include/butil/reader_writer.h
2022-12-14 19:05:52 +08:00

54 lines
1.8 KiB
C++

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you 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
//
// http://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.
// Date: Wed Aug 8 05:51:33 PDT 2018
#ifndef BUTIL_READER_WRITER_H
#define BUTIL_READER_WRITER_H
#include <sys/uio.h> // iovec
namespace butil {
// Abstraction for reading data.
// The simplest implementation is to embed a file descriptor and read from it.
class IReader {
public:
virtual ~IReader() {}
// Semantics of parameters and return value are same as readv(2) except that
// there's no `fd'.
virtual ssize_t ReadV(const iovec* iov, int iovcnt) = 0;
};
// Abstraction for writing data.
// The simplest implementation is to embed a file descriptor and writev into it.
class IWriter {
public:
virtual ~IWriter() {}
// Semantics of parameters and return value are same as writev(2) except that
// there's no `fd'.
// WriteV is required to submit data gathered by multiple appends in one
// run and enable the possibility of atomic writes.
virtual ssize_t WriteV(const iovec* iov, int iovcnt) = 0;
};
} // namespace butil
#endif // BUTIL_READER_WRITER_H