IOStream.h

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// -*- mode: C++; indent-tabs-mode: nil; c-basic-offset: 4; tab-width: 4; -*-
// vim: set shiftwidth=4 softtabstop=4 expandtab:
/*
 ********************************************************************
 ** NIDAS: NCAR In-situ Data Acquistion Software
 **
 ** 2005, Copyright University Corporation for Atmospheric Research
 **
 ** This program is free software; you can redistribute it and/or modify
 ** it under the terms of the GNU General Public License as published by
 ** the Free Software Foundation; either version 2 of the License, or
 ** (at your option) any later version.
 **
 ** This program is distributed in the hope that it will be useful,
 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 ** GNU General Public License for more details.
 **
 ** The LICENSE.txt file accompanying this software contains
 ** a copy of the GNU General Public License. If it is not found,
 ** write to the Free Software Foundation, Inc.,
 ** 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 **
 ********************************************************************
*/

#ifndef NIDAS_CORE_IOSTREAM_H
#define NIDAS_CORE_IOSTREAM_H

#include "IOChannel.h"

#include <iostream>

namespace nidas { namespace core {

class IOStream;

class IOStream {

public:
    IOStream(IOChannel& input,size_t buflen = 8192);

    virtual ~IOStream();

    size_t available() const
    {
        return _head - _tail;
    }

    bool isNewInput() const { return _newInput; }

    size_t read() throw(nidas::util::IOException);

    size_t readBuf(void* buf, size_t len) throw()
    {
        size_t l = available();
        if (len > l) len = l;
        if (len == 0) return len;
        memcpy(buf,_tail,len);
        _tail += len;
        addNumInputBytes(len);
        return len;
    }

    size_t read(void* buf, size_t len) throw(nidas::util::IOException);

    size_t skip(size_t len) throw(nidas::util::IOException);

    size_t backup(size_t len) throw();

    size_t backup() throw();

    size_t readUntil(void* buf, size_t len,char term) throw(nidas::util::IOException);

    size_t write(const struct iovec* iov, int nbufs,bool flush)
    throw(nidas::util::IOException);

    size_t write(const void*buf,size_t len,bool flush) throw (nidas::util::IOException);

    void flush() throw(nidas::util::IOException);

    dsm_time_t createFile(dsm_time_t t,bool exact) throw(nidas::util::IOException)
    {
    // std::cerr << "IOStream::createFile, doing flush" << std::endl;
    flush();
    return _iochannel.createFile(t,exact);
    }

    const std::string& getName() const { return _iochannel.getName(); }

    long long getNumInputBytes() const { return _nbytesIn; }

    void addNumInputBytes(int val) { _nbytesIn += val; }

    long long getNumOutputBytes() const { return _nbytesOut; }

    void addNumOutputBytes(int val) { _nbytesOut += val; }

protected:

    IOChannel& _iochannel;

    void reallocateBuffer(size_t len);

private:
    char *_buffer;

    char* _head;

    char* _tail;

    size_t _buflen;

    size_t _halflen;

    char* _eob;

    bool _newInput;

    long long _nbytesIn;

    long long _nbytesOut;

    size_t _nEAGAIN;

    IOStream(const IOStream&);

    IOStream& operator=(const IOStream&);

};

}}  // namespace nidas namespace core

#endif