LineReader.cpp

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/****************************************************************************/
// Retrieves a file linewise and reports the lines to a handler.
/****************************************************************************/
// SUMO, Simulation of Urban MObility; see http://sumo.sourceforge.net/
// Copyright 2001-2010 DLR (http://www.dlr.de/) and contributors
/****************************************************************************/
//
//   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.
//
/****************************************************************************/


// ===========================================================================
// included modules
// ===========================================================================
#ifdef _MSC_VER
#include <windows_config.h>
#else
#include <config.h>
#endif

#include <string>
#include <fstream>
#include <iostream>
#include <algorithm>
#include <sstream>
#include <utils/common/UtilExceptions.h>
#include "LineHandler.h"
#include "LineReader.h"

#ifdef CHECK_MEMORY_LEAKS
#include <foreign/nvwa/debug_new.h>
#endif // CHECK_MEMORY_LEAKS


// ===========================================================================
// method definitions
// ===========================================================================
LineReader::LineReader() throw() {}


LineReader::LineReader(const std::string &file) throw()
        : myFileName(file),
        myRead(0) {
    reinit();
}


LineReader::~LineReader() throw() {}


bool
LineReader::hasMore() const throw() {
    return myRread<myAvailable;
}


void
LineReader::readAll(LineHandler &lh) throw(ProcessError) {
    while (myRread<myAvailable) {
        if (!readLine(lh)) {
            return;
        }
    }
}


bool
LineReader::readLine(LineHandler &lh) throw(ProcessError) {
    std::string toReport;
    bool moreAvailable = true;
    while (toReport.length()==0) {
        size_t idx = myStrBuffer.find('\n');
        if (idx==0) {
            myStrBuffer = myStrBuffer.substr(1);
            myRread++;
            return lh.report("");
        }
        if (idx!=std::string::npos) {
            toReport = myStrBuffer.substr(0, idx);
            myStrBuffer = myStrBuffer.substr(idx+1);
            myRread += idx+1;
        } else {
            if (myRead<myAvailable) {
                myStrm.read(myBuffer,
                            myAvailable - myRead<1024
                            ? myAvailable - myRead
                            : 1024);
                size_t noBytes = myAvailable - myRead;
                noBytes = noBytes > 1024 ? 1024 : noBytes;
                myStrBuffer += std::string(myBuffer, noBytes);
                myRead += 1024;
            } else {
                toReport = myStrBuffer;
                moreAvailable = false;
                if (toReport=="") {
                    return lh.report(toReport);
                }
            }
        }
    }
    // remove trailing blanks
    int idx = (int)toReport.length()-1;
    while (idx>=0&&toReport[idx]<32) {
        idx--;
    }
    if (idx>=0) {
        toReport = toReport.substr(0, idx+1);
    } else {
        toReport = "";
    }
    // give it to the handler
    if (!lh.report(toReport)) {
        return false;
    }
    return moreAvailable;
}


std::string
LineReader::readLine() throw() {
    std::string toReport;
    bool moreAvailable = true;
    while (toReport.length()==0&&myStrm.good()) {
        size_t idx = myStrBuffer.find('\n');
        if (idx==0) {
            myStrBuffer = myStrBuffer.substr(1);
            myRread++;
            return "";
        }
        if (idx!=std::string::npos) {
            toReport = myStrBuffer.substr(0, idx);
            myStrBuffer = myStrBuffer.substr(idx+1);
            myRread += idx+1;
        } else {
            if (myRead<myAvailable) {
                myStrm.read(myBuffer,
                            myAvailable - myRead<1024
                            ? myAvailable - myRead
                            : 1024);
                size_t noBytes = myAvailable - myRead;
                noBytes = noBytes > 1024 ? 1024 : noBytes;
                myStrBuffer += std::string(myBuffer, noBytes);
                myRead += 1024;
            } else {
                toReport = myStrBuffer;
                myRread += 1024;
                moreAvailable = false;
                if (toReport=="") {
                    return toReport;
                }
            }
        }
    }
    if (!myStrm.good()) {
        return "";
    }
    // remove trailing blanks
    int idx = (int)toReport.length()-1;
    while (idx>=0&&toReport[idx]<32) {
        idx--;
    }
    if (idx>=0) {
        toReport = toReport.substr(0, idx+1);
    } else {
        toReport = "";
    }
    return toReport;
}



std::string
LineReader::getFileName() const throw() {
    return myFileName;
}


bool
LineReader::setFile(const std::string &file) throw() {
    myFileName = file;
    reinit();
    return myStrm.good();
}


unsigned long
LineReader::getPosition() throw() {
    return myRread;
}


void
LineReader::reinit() throw() {
    if (myStrm.is_open()) {
        myStrm.close();
    }
    myStrm.clear();
    myStrm.open(myFileName.c_str(), std::ios::binary);
    myStrm.unsetf(std::ios::skipws);
    myStrm.seekg(0, std::ios::end);
    myAvailable = myStrm.tellg();
    myStrm.seekg(0, std::ios::beg);
    myRead = 0;
    myRread = 0;
    myStrBuffer = "";
}


void
LineReader::setPos(unsigned long pos) throw() {
    myStrm.seekg(pos, std::ios::beg);
    myRead = pos;
    myRread = pos;
    myStrBuffer = "";
}


bool
LineReader::good() const throw() {
    return myStrm.good();
}



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