TarsCpp/util/src/tc_fifo.cpp

/**
 * Tencent is pleased to support the open source community by making Tars available.
 *
 * Copyright (C) 2016THL A29 Limited, a Tencent company. All rights reserved.
 *
 * Licensed under the BSD 3-Clause License (the "License"); you may not use this file except 
 * in compliance with the License. You may obtain a copy of the License at
 *
 * https://opensource.org/licenses/BSD-3-Clause
 *
 * 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.
 */
#if TARGET_PLATFORM_LINUX || TARGET_PLATFORM_IOS

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>

#include "util/tc_fifo.h"

namespace tars
{

///////////////////////////////////////////////////////////////////////////////////////////////////
// 
TC_Fifo::TC_Fifo(bool bOwner) : _bOwner(bOwner), _enRW(EM_READ), _fd(-1)
{

}

TC_Fifo::~TC_Fifo()
{
    if (_bOwner) close();
}

void TC_Fifo::close()
{
    if (_fd >= 0) ::close(_fd); 
        
    _fd = -1;
}

int TC_Fifo::open(const std::string & sPathName, ENUM_RW_SET enRW, mode_t mode)
{
    _enRW       = enRW;
    _sPathName    = sPathName;

    if (_enRW != EM_READ && _enRW != EM_WRITE)
    {
        return -1;
    }

    if (::mkfifo(_sPathName.c_str(), mode) == -1 && errno != EEXIST)
    {
        return -1;
    }

    if (_enRW == EM_READ  && (_fd = ::open(_sPathName.c_str(), O_NONBLOCK|O_RDONLY, 0664)) < 0)
    {
        return -1;
    }

    if (_enRW == EM_WRITE && (_fd = ::open(_sPathName.c_str(), O_NONBLOCK|O_WRONLY, 0664)) < 0)
    {
        return -1;
    }

    return 0;
}

int TC_Fifo::read(char * szBuff, const size_t sizeMax)
{
    return ::read(_fd, szBuff, sizeMax);
}

int TC_Fifo::write(const char * szBuff, const size_t sizeBuffLen)
{
    if (sizeBuffLen == 0) return 0;

    return ::write(_fd, szBuff, sizeBuffLen);
}

}

#endif