DeflaterOutputStream.java

/*
 * Copyright (c) 2011 ymnk, JCraft,Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of conditions
 * and the following disclaimer.
 *
 * 2. 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.
 *
 * 3. The names of the authors may not be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 JCRAFT, INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE 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 com.jcraft.jsch.jzlib;

import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;

final class DeflaterOutputStream extends FilterOutputStream {

  protected final Deflater deflater;

  protected byte[] buffer;

  private boolean closed = false;

  private boolean syncFlush = false;

  private final byte[] buf1 = new byte[1];

  protected boolean mydeflater = false;

  private boolean close_out = true;

  protected static final int DEFAULT_BUFSIZE = 512;

  DeflaterOutputStream(OutputStream out) throws IOException {
    this(out, new Deflater(JZlib.Z_DEFAULT_COMPRESSION), DEFAULT_BUFSIZE, true);
    mydeflater = true;
  }

  DeflaterOutputStream(OutputStream out, Deflater def) throws IOException {
    this(out, def, DEFAULT_BUFSIZE, true);
  }

  DeflaterOutputStream(OutputStream out, Deflater deflater, int size) throws IOException {
    this(out, deflater, size, true);
  }

  DeflaterOutputStream(OutputStream out, Deflater deflater, int size, boolean close_out)
      throws IOException {
    super(out);
    if (out == null || deflater == null) {
      throw new NullPointerException();
    } else if (size <= 0) {
      throw new IllegalArgumentException("buffer size must be greater than 0");
    }
    this.deflater = deflater;
    buffer = new byte[size];
    this.close_out = close_out;
  }

  @Override
  public void write(int b) throws IOException {
    buf1[0] = (byte) (b & 0xff);
    write(buf1, 0, 1);
  }

  @Override
  public void write(byte[] b, int off, int len) throws IOException {
    if (deflater.finished()) {
      throw new IOException("finished");
    } else if (off < 0 || len < 0 || off + len > b.length) {
      throw new IndexOutOfBoundsException();
    } else if (len == 0) {
      return;
    } else {
      int flush = syncFlush ? JZlib.Z_SYNC_FLUSH : JZlib.Z_NO_FLUSH;
      deflater.setInput(b, off, len, true);
      while (deflater.avail_in > 0) {
        int err = deflate(flush);
        if (err == JZlib.Z_STREAM_END)
          break;
      }
    }
  }

  void finish() throws IOException {
    while (!deflater.finished()) {
      deflate(JZlib.Z_FINISH);
    }
  }

  @Override
  public void close() throws IOException {
    if (!closed) {
      finish();
      if (mydeflater) {
        deflater.end();
      }
      if (close_out)
        out.close();
      closed = true;
    }
  }

  @SuppressWarnings("fallthrough")
  protected int deflate(int flush) throws IOException {
    deflater.setOutput(buffer, 0, buffer.length);
    int err = deflater.deflate(flush);
    switch (err) {
      case JZlib.Z_OK:
      case JZlib.Z_STREAM_END:
        break;
      case JZlib.Z_BUF_ERROR:
        if (deflater.avail_in <= 0 && flush != JZlib.Z_FINISH) {
          // flush() without any data
          break;
        }
      default:
        throw new IOException(
            "failed to deflate: error=" + err + " avail_out=" + deflater.avail_out);
    }
    int len = deflater.next_out_index;
    if (len > 0) {
      out.write(buffer, 0, len);
    }
    return err;
  }

  @Override
  public void flush() throws IOException {
    if (syncFlush && !deflater.finished()) {
      while (true) {
        int err = deflate(JZlib.Z_SYNC_FLUSH);
        if (deflater.next_out_index < buffer.length)
          break;
        if (err == JZlib.Z_STREAM_END)
          break;
      }
    }
    out.flush();
  }

  long getTotalIn() {
    return deflater.getTotalIn();
  }

  long getTotalOut() {
    return deflater.getTotalOut();
  }

  void setSyncFlush(boolean syncFlush) {
    this.syncFlush = syncFlush;
  }

  boolean getSyncFlush() {
    return this.syncFlush;
  }

  Deflater getDeflater() {
    return deflater;
  }
}