/* Generated By: CSCC: 4.0 (07/17/2009)  Do not edit this line. SimpleCharStream.cs Version 4.0 */
using System;
namespace edu.neu.ccs.demeterf.http.classes{

/**
 * An implementation of interface CharStream, where the stream is assumed to
 * contain only ASCII characters (without unicode processing).
 */

public class SimpleCharStream{
  public static bool staticFlag = false;
  int bufsize;
  int available;
  int tokenBegin;
  public int bufpos = -1;
  protected int[] bufline;
  protected int[] bufcolumn;

  protected int column = 0;
  protected int line = 1;

  protected bool prevCharIsCR = false;
  protected bool prevCharIsLF = false;

  protected System.IO.TextReader inputStream;

  protected char[] buffer;
  protected int maxNextCharInd = 0;
  protected int inBuf = 0;
  protected int tabSize = 8;

  protected void setTabSize(int i) { tabSize = i; }
  protected int getTabSize(int i) { return tabSize; }


  protected void ExpandBuff(bool wrapAround){
     char[] newbuffer = new char[bufsize + 2048];
     int[] newbufline = new int[bufsize + 2048];
     int[] newbufcolumn = new int[bufsize + 2048];

     try{
        if (wrapAround){
           System.Array.Copy(buffer, tokenBegin, newbuffer, 0, bufsize - tokenBegin);
           System.Array.Copy(buffer, 0, newbuffer,
                                             bufsize - tokenBegin, bufpos);
           buffer = newbuffer;

           System.Array.Copy(bufline, tokenBegin, newbufline, 0, bufsize - tokenBegin);
           System.Array.Copy(bufline, 0, newbufline, bufsize - tokenBegin, bufpos);
           bufline = newbufline;

           System.Array.Copy(bufcolumn, tokenBegin, newbufcolumn, 0, bufsize - tokenBegin);
           System.Array.Copy(bufcolumn, 0, newbufcolumn, bufsize - tokenBegin, bufpos);
           bufcolumn = newbufcolumn;

           maxNextCharInd = (bufpos += (bufsize - tokenBegin));
        }else{
           System.Array.Copy(buffer, tokenBegin, newbuffer, 0, bufsize - tokenBegin);
           buffer = newbuffer;

           System.Array.Copy(bufline, tokenBegin, newbufline, 0, bufsize - tokenBegin);
           bufline = newbufline;

           System.Array.Copy(bufcolumn, tokenBegin, newbufcolumn, 0, bufsize - tokenBegin);
           bufcolumn = newbufcolumn;

           maxNextCharInd = (bufpos -= tokenBegin);
        }
     }catch (System.Exception t){
        throw new System.Exception(t.ToString());
     }


     bufsize += 2048;
     available = bufsize;
     tokenBegin = 0;
  }

  bool stream_closed = false;
  protected void FillBuff(){
     if (maxNextCharInd == available){
        if (available == bufsize){
           if (tokenBegin > 2048){
              bufpos = maxNextCharInd = 0;
              available = tokenBegin;
           }else if (tokenBegin < 0)
              bufpos = maxNextCharInd = 0;
           else
              ExpandBuff(false);
        }else if (available > tokenBegin)
           available = bufsize;
        else if ((tokenBegin - available) < 2048)
           ExpandBuff(true);
        else
           available = tokenBegin;
     }

     int i;
     try {
        if (stream_closed || (i = inputStream.Read(buffer, maxNextCharInd, available - maxNextCharInd)) <= 0){
           stream_closed = true;
           inputStream.Close();
           throw new System.IO.IOException();
        }else
           maxNextCharInd += i;
        return;
     }
     catch(System.IO.IOException e) {
        --bufpos;
        backup(0);
        if (tokenBegin == -1)
           tokenBegin = bufpos;
        throw e;
     }
  }

  public char BeginToken(){
     tokenBegin = -1;
     char c = readChar();
     tokenBegin = bufpos;

     return c;
  }

  protected void UpdateLineColumn(char c){
     column++;

     if (prevCharIsLF){
        prevCharIsLF = false;
        line += (column = 1);
     }
     else if (prevCharIsCR){
        prevCharIsCR = false;
        if (c == '\n'){
           prevCharIsLF = true;
        }else
           line += (column = 1);
     }

     switch (c){
        case '\r' :
           prevCharIsCR = true;
           break;
        case '\n' :
           prevCharIsLF = true;
           break;
        case '\t' :
           column--;
           column += (tabSize - (column % tabSize));
           break;
        default :
           break;
     }

     bufline[bufpos] = line;
     bufcolumn[bufpos] = column;
  }

  public char readChar(){
     if (inBuf > 0){
        --inBuf;

        if (++bufpos == bufsize)
           bufpos = 0;

        return buffer[bufpos];
     }

     if (++bufpos >= maxNextCharInd)
        FillBuff();

     char c = buffer[bufpos];

     UpdateLineColumn(c);
     return (c);
  }

  /**
   * @deprecated 
   * @see #getEndColumn
   */

  public int getColumn() {
     return bufcolumn[bufpos];
  }

  /**
   * @deprecated 
   * @see #getEndLine
   */

  public int getLine() {
     return bufline[bufpos];
  }

  public int getEndColumn() {
     return bufcolumn[bufpos];
  }

  public int getEndLine() {
     return bufline[bufpos];
  }

  public int getBeginColumn() {
     return bufcolumn[tokenBegin];
  }

  public int getBeginLine() {
     return bufline[tokenBegin];
  }

  public void backup(int amount) {

    inBuf += amount;
    if ((bufpos -= amount) < 0)
       bufpos += bufsize;
  }

  public SimpleCharStream(System.IO.TextReader dstream, int startline, int startcolumn, int buffersize){
    inputStream = dstream;
    line = startline;
    column = startcolumn - 1;

    available = bufsize = buffersize;
    buffer = new char[buffersize];
    bufline = new int[buffersize];
    bufcolumn = new int[buffersize];
  }

  public SimpleCharStream(System.IO.TextReader dstream, int startline, int startcolumn)
   : this(dstream, startline, startcolumn, 4096){}

  public SimpleCharStream(System.IO.TextReader dstream)
    : this(dstream, 1, 1, 4096){}

  public void ReInit(System.IO.TextReader dstream, int startline, int startcolumn, int buffersize){
    inputStream = dstream;
    line = startline;
    column = startcolumn - 1;

    if (buffer == null || buffersize != buffer.Length){
      available = bufsize = buffersize;
      buffer = new char[buffersize];
      bufline = new int[buffersize];
      bufcolumn = new int[buffersize];
    }
    prevCharIsLF = prevCharIsCR = false;
    tokenBegin = inBuf = maxNextCharInd = 0;
    bufpos = -1;
  }

  public void ReInit(System.IO.TextReader dstream, int startline, int startcolumn){
     ReInit(dstream, startline, startcolumn, 4096);
  }

  public void ReInit(System.IO.TextReader dstream){
     ReInit(dstream, 1, 1, 4096);
  }
  public SimpleCharStream(System.IO.Stream dstream, int startline, int startcolumn, int buffersize)
    : this(new System.IO.StreamReader(dstream), startline, startcolumn, buffersize){}

  public SimpleCharStream(System.IO.Stream dstream, int startline, int startcolumn)
    : this(dstream, startline, startcolumn, 4096){}

  public SimpleCharStream(System.IO.Stream dstream)
    : this(dstream, 1, 1, 4096){}


  public void ReInit(System.IO.Stream dstream, int startline, int startcolumn, int buffersize){
     ReInit(new System.IO.StreamReader(dstream), startline, startcolumn, buffersize);
  }


  public void ReInit(System.IO.Stream dstream){
     ReInit(dstream, 1, 1, 4096);
  }
  public void ReInit(System.IO.Stream dstream, int startline, int startcolumn){
     ReInit(dstream, startline, startcolumn, 4096);
  }
  public String GetImage(){
     if (bufpos >= tokenBegin)
        return new String(buffer, tokenBegin, bufpos - tokenBegin + 1);
     else
        return new String(buffer, tokenBegin, bufsize - tokenBegin) +
                              new String(buffer, 0, bufpos + 1);
  }

  public char[] GetSuffix(int len){
     char[] ret = new char[len];

     if ((bufpos + 1) >= len)
        System.Array.Copy(buffer, bufpos - len + 1, ret, 0, len);
     else{
        System.Array.Copy(buffer, bufsize - (len - bufpos - 1), ret, 0, len - bufpos - 1);
        System.Array.Copy(buffer, 0, ret, len - bufpos - 1, bufpos + 1);
     }

     return ret;
  }

  public void Done(){
     buffer = null;
     bufline = null;
     bufcolumn = null;
  }

  /**
   * Method to adjust line and column numbers for the start of a token.
   */
  public void adjustBeginLineColumn(int newLine, int newCol){
     int start = tokenBegin;
     int len;

     if (bufpos >= tokenBegin){
        len = bufpos - tokenBegin + inBuf + 1;
     }else{
        len = bufsize - tokenBegin + bufpos + 1 + inBuf;
     }

     int i = 0, j = 0, k = 0;
     int nextColDiff = 0, columnDiff = 0;

     while (i < len && bufline[j = start % bufsize] == bufline[k = ++start % bufsize]){
        bufline[j] = newLine;
        nextColDiff = columnDiff + bufcolumn[k] - bufcolumn[j];
        bufcolumn[j] = newCol + columnDiff;
        columnDiff = nextColDiff;
        i++;
     } 

     if (i < len){
        bufline[j] = newLine++;
        bufcolumn[j] = newCol + columnDiff;

        while (i++ < len){
           if (bufline[j = start % bufsize] != bufline[++start % bufsize])
              bufline[j] = newLine++;
           else
              bufline[j] = newLine;
        }
     }

     line = bufline[j];
     column = bufcolumn[j];
  }

}

}