/*
 * Copyright (c) 2003, KNOPFLERFISH project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 * - Neither the name of the KNOPFLERFISH project nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.knopflerfish.bundle.http;

import java.io.InputStream;
import java.io.IOException;

import javax.servlet.ServletInputStream;


public class ServletInputStreamImpl extends ServletInputStream {

  private boolean isLimited = false;
  private volatile int available;
  private final InputStream is;
  private byte[] lineBuffer = null;

  public ServletInputStreamImpl(final InputStream is) {
    this(is, -1);
  }

  public ServletInputStreamImpl(final InputStream is, final int available) {

    this.is = is;

    setLimit(available);
  }

  public void setLimit(int available) {

    this.available = available;
    this.isLimited = available != -1;
  }

  public int read() throws IOException {

    if (isLimited && --available < 0)
      return -1;

    return is.read();
  }

  public String readLine() throws IOException {

    if (lineBuffer == null)
      lineBuffer = new byte[127];

    int count = readLine(lineBuffer, 0, lineBuffer.length);
    int offset = count;

    while (count > 0 &&
           offset == lineBuffer.length &&
           lineBuffer[offset - 1] != '\n') {
      // double the size of the buffer
      byte[] tmp = new byte[offset * 2 + 1];
      System.arraycopy(lineBuffer, 0, tmp, 0, offset);
      lineBuffer = tmp;
      tmp = null;

      count = readLine(lineBuffer, offset, lineBuffer.length - offset);
      offset += count;
    }

    if (count == -1)
      throw new IOException("End of stream reached before CRLF");

    return HttpUtil.newString(lineBuffer, 0, 0, offset - 2); // remove CRLF
  }

} // ServletInputStreamImpl