Lucene example source code file (JavaCharStream.java)

This example Lucene source code file (JavaCharStream.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lucene tags/keywords

adjustbuffsize, b, d, deprecated, expandbuff, fillbuff, readbyte, readbyte, reinit, reinit, string, string, updatelinecolumn, updatelinecolumn

The Lucene JavaCharStream.java source code

/* Generated By:JavaCC: Do not edit this line. JavaCharStream.java Version 4.1 */
/* JavaCCOptions:STATIC=false */
package org.apache.lucene.queryParser.standard.parser;

/**
 * An implementation of interface CharStream, where the stream is assumed to
 * contain only ASCII characters (with java-like unicode escape processing).
 */

public class JavaCharStream
{
/** Whether parser is static. */
  public static final boolean staticFlag = false;
  static final int hexval(char c) throws java.io.IOException {
    switch(c)
    {
       case '0' :
          return 0;
       case '1' :
          return 1;
       case '2' :
          return 2;
       case '3' :
          return 3;
       case '4' :
          return 4;
       case '5' :
          return 5;
       case '6' :
          return 6;
       case '7' :
          return 7;
       case '8' :
          return 8;
       case '9' :
          return 9;

       case 'a' :
       case 'A' :
          return 10;
       case 'b' :
       case 'B' :
          return 11;
       case 'c' :
       case 'C' :
          return 12;
       case 'd' :
       case 'D' :
          return 13;
       case 'e' :
       case 'E' :
          return 14;
       case 'f' :
       case 'F' :
          return 15;
    }

    throw new java.io.IOException(); // Should never come here
  }

/** Position in buffer. */
  public int bufpos = -1;
  int bufsize;
  int available;
  int tokenBegin;
  protected int bufline[];
  protected int bufcolumn[];

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

  protected boolean prevCharIsCR = false;
  protected boolean prevCharIsLF = false;

  protected java.io.Reader inputStream;

  protected char[] nextCharBuf;
  protected char[] buffer;
  protected int maxNextCharInd = 0;
  protected int nextCharInd = -1;
  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(boolean wrapAround)
  {
     char[] newbuffer = new char[bufsize + 2048];
     int newbufline[] = new int[bufsize + 2048];
     int newbufcolumn[] = new int[bufsize + 2048];

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

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

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

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

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

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

           bufpos -= tokenBegin;
        }
     }
     catch (Throwable t)
     {
        throw new Error(t.getMessage());
     }

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

  protected void FillBuff() throws java.io.IOException
  {
     int i;
     if (maxNextCharInd == 4096)
        maxNextCharInd = nextCharInd = 0;

     try {
        if ((i = inputStream.read(nextCharBuf, maxNextCharInd,
                                            4096 - maxNextCharInd)) == -1)
        {
           inputStream.close();
           throw new java.io.IOException();
        }
        else
           maxNextCharInd += i;
        return;
     }
     catch(java.io.IOException e) {
        if (bufpos != 0)
        {
           --bufpos;
           backup(0);
        }
        else
        {
           bufline[bufpos] = line;
           bufcolumn[bufpos] = column;
        }
        throw e;
     }
  }

  protected char ReadByte() throws java.io.IOException
  {
     if (++nextCharInd >= maxNextCharInd)
        FillBuff();

     return nextCharBuf[nextCharInd];
  }

/** @return starting character for token. */
  public char BeginToken() throws java.io.IOException
  {
     if (inBuf > 0)
     {
        --inBuf;

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

        tokenBegin = bufpos;
        return buffer[bufpos];
     }

     tokenBegin = 0;
     bufpos = -1;

     return readChar();
  }

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

  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;
  }

/** Read a character. */
  public char readChar() throws java.io.IOException
  {
     if (inBuf > 0)
     {
        --inBuf;

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

        return buffer[bufpos];
     }

     char c;

     if (++bufpos == available)
        AdjustBuffSize();

     if ((buffer[bufpos] = c = ReadByte()) == '\\')
     {
        UpdateLineColumn(c);

        int backSlashCnt = 1;

        for (;;) // Read all the backslashes
        {
           if (++bufpos == available)
              AdjustBuffSize();

           try
           {
              if ((buffer[bufpos] = c = ReadByte()) != '\\')
              {
                 UpdateLineColumn(c);
                 // found a non-backslash char.
                 if ((c == 'u') && ((backSlashCnt & 1) == 1))
                 {
                    if (--bufpos < 0)
                       bufpos = bufsize - 1;

                    break;
                 }

                 backup(backSlashCnt);
                 return '\\';
              }
           }
           catch(java.io.IOException e)
           {
              if (backSlashCnt > 1)
                 backup(backSlashCnt-1);

              return '\\';
           }

           UpdateLineColumn(c);
           backSlashCnt++;
        }

        // Here, we have seen an odd number of backslash's followed by a 'u'
        try
        {
           while ((c = ReadByte()) == 'u')
              ++column;

           buffer[bufpos] = c = (char)(hexval(c) << 12 |
                                       hexval(ReadByte()) << 8 |
                                       hexval(ReadByte()) << 4 |
                                       hexval(ReadByte()));

           column += 4;
        }
        catch(java.io.IOException e)
        {
           throw new Error("Invalid escape character at line " + line +
                                         " column " + column + ".");
        }

        if (backSlashCnt == 1)
           return c;
        else
        {
           backup(backSlashCnt - 1);
           return '\\';
        }
     }
     else
     {
        UpdateLineColumn(c);
        return c;
     }
  }

  @Deprecated
  /**
   * @deprecated
   * @see #getEndColumn
   */
  public int getColumn() {
     return bufcolumn[bufpos];
  }

  @Deprecated
  /**
   * @deprecated
   * @see #getEndLine
   */
  public int getLine() {
     return bufline[bufpos];
  }

/** Get end column. */
  public int getEndColumn() {
     return bufcolumn[bufpos];
  }

/** Get end line. */
  public int getEndLine() {
     return bufline[bufpos];
  }

/** @return column of token start */
  public int getBeginColumn() {
     return bufcolumn[tokenBegin];
  }

/** @return line number of token start */
  public int getBeginLine() {
     return bufline[tokenBegin];
  }

/** Retreat. */
  public void backup(int amount) {

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

/** Constructor. */
  public JavaCharStream(java.io.Reader 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];
    nextCharBuf = new char[4096];
  }

/** Constructor. */
  public JavaCharStream(java.io.Reader dstream,
                                        int startline, int startcolumn)
  {
     this(dstream, startline, startcolumn, 4096);
  }

/** Constructor. */
  public JavaCharStream(java.io.Reader dstream)
  {
     this(dstream, 1, 1, 4096);
  }
/** Reinitialise. */
  public void ReInit(java.io.Reader 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];
      nextCharBuf = new char[4096];
    }
    prevCharIsLF = prevCharIsCR = false;
    tokenBegin = inBuf = maxNextCharInd = 0;
    nextCharInd = bufpos = -1;
  }

/** Reinitialise. */
  public void ReInit(java.io.Reader dstream,
                                        int startline, int startcolumn)
  {
     ReInit(dstream, startline, startcolumn, 4096);
  }

/** Reinitialise. */
  public void ReInit(java.io.Reader dstream)
  {
     ReInit(dstream, 1, 1, 4096);
  }
/** Constructor. */
  public JavaCharStream(java.io.InputStream dstream, String encoding, int startline,
  int startcolumn, int buffersize) throws java.io.UnsupportedEncodingException
  {
     this(encoding == null ? new java.io.InputStreamReader(dstream) : new java.io.InputStreamReader(dstream, encoding), startline, startcolumn, buffersize);
  }

/** Constructor. */
  public JavaCharStream(java.io.InputStream dstream, int startline,
  int startcolumn, int buffersize)
  {
     this(new java.io.InputStreamReader(dstream), startline, startcolumn, 4096);
  }

/** Constructor. */
  public JavaCharStream(java.io.InputStream dstream, String encoding, int startline,
                        int startcolumn) throws java.io.UnsupportedEncodingException
  {
     this(dstream, encoding, startline, startcolumn, 4096);
  }

/** Constructor. */
  public JavaCharStream(java.io.InputStream dstream, int startline,
                        int startcolumn)
  {
     this(dstream, startline, startcolumn, 4096);
  }

/** Constructor. */
  public JavaCharStream(java.io.InputStream dstream, String encoding) throws java.io.UnsupportedEncodingException
  {
     this(dstream, encoding, 1, 1, 4096);
  }

/** Constructor. */
  public JavaCharStream(java.io.InputStream dstream)
  {
     this(dstream, 1, 1, 4096);
  }

/** Reinitialise. */
  public void ReInit(java.io.InputStream dstream, String encoding, int startline,
  int startcolumn, int buffersize) throws java.io.UnsupportedEncodingException
  {
     ReInit(encoding == null ? new java.io.InputStreamReader(dstream) : new java.io.InputStreamReader(dstream, encoding), startline, startcolumn, buffersize);
  }

/** Reinitialise. */
  public void ReInit(java.io.InputStream dstream, int startline,
  int startcolumn, int buffersize)
  {
     ReInit(new java.io.InputStreamReader(dstream), startline, startcolumn, buffersize);
  }
/** Reinitialise. */
  public void ReInit(java.io.InputStream dstream, String encoding, int startline,
                     int startcolumn) throws java.io.UnsupportedEncodingException
  {
     ReInit(dstream, encoding, startline, startcolumn, 4096);
  }
/** Reinitialise. */
  public void ReInit(java.io.InputStream dstream, int startline,
                     int startcolumn)
  {
     ReInit(dstream, startline, startcolumn, 4096);
  }
/** Reinitialise. */
  public void ReInit(java.io.InputStream dstream, String encoding) throws java.io.UnsupportedEncodingException
  {
     ReInit(dstream, encoding, 1, 1, 4096);
  }

/** Reinitialise. */
  public void ReInit(java.io.InputStream dstream)
  {
     ReInit(dstream, 1, 1, 4096);
  }

  /** @return token image as String */
  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);
  }

  /** @return suffix */
  public char[] GetSuffix(int len)
  {
     char[] ret = new char[len];

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

     return ret;
  }

  /** Set buffers back to null when finished. */
  public void Done()
  {
     nextCharBuf = null;
     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];
  }

}
/* JavaCC - OriginalChecksum=f19c73b8f7faf94cc4a581e7b2933cc6 (do not edit this line) */