8203328: Rename EFS in java.util.zip internals to something meaningful
Reviewed-by: sherman

   1 /*
   2  * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.util.zip;
  27 
  28 import java.io.FilterOutputStream;
  29 import java.io.OutputStream;
  30 import java.io.InputStream;
  31 import java.io.IOException;
  32 
  33 /**
  34  * This class implements an output stream filter for compressing data in
  35  * the "deflate" compression format. It is also used as the basis for other
  36  * types of compression filters, such as GZIPOutputStream.
  37  *
  38  * @see         Deflater
  39  * @author      David Connelly
  40  * @since 1.1
  41  */
  42 public
  43 class DeflaterOutputStream extends FilterOutputStream {
  44     /**
  45      * Compressor for this stream.
  46      */
  47     protected Deflater def;
  48 
  49     /**
  50      * Output buffer for writing compressed data.
  51      */
  52     protected byte[] buf;
  53 
  54     /**
  55      * Indicates that the stream has been closed.
  56      */

  57     private boolean closed = false;
  58 
  59     private final boolean syncFlush;
  60 
  61     /**
  62      * Creates a new output stream with the specified compressor,
  63      * buffer size and flush mode.
  64      *
  65      * @param out the output stream
  66      * @param def the compressor ("deflater")
  67      * @param size the output buffer size
  68      * @param syncFlush
  69      *        if {@code true} the {@link #flush()} method of this
  70      *        instance flushes the compressor with flush mode
  71      *        {@link Deflater#SYNC_FLUSH} before flushing the output
  72      *        stream, otherwise only flushes the output stream
  73      *
  74      * @throws IllegalArgumentException if {@code size <= 0}
  75      *
  76      * @since 1.7
  77      */
  78     public DeflaterOutputStream(OutputStream out,
  79                                 Deflater def,
  80                                 int size,
  81                                 boolean syncFlush) {
  82         super(out);
  83         if (out == null || def == null) {
  84             throw new NullPointerException();
  85         } else if (size <= 0) {
  86             throw new IllegalArgumentException("buffer size <= 0");
  87         }
  88         this.def = def;
  89         this.buf = new byte[size];
  90         this.syncFlush = syncFlush;
  91     }
  92 
  93 
  94     /**
  95      * Creates a new output stream with the specified compressor and
  96      * buffer size.
  97      *
  98      * <p>The new output stream instance is created as if by invoking
  99      * the 4-argument constructor DeflaterOutputStream(out, def, size, false).
 100      *
 101      * @param out the output stream
 102      * @param def the compressor ("deflater")
 103      * @param size the output buffer size
 104      * @exception IllegalArgumentException if {@code size <= 0}
 105      */
 106     public DeflaterOutputStream(OutputStream out, Deflater def, int size) {
 107         this(out, def, size, false);
 108     }
 109 
 110     /**
 111      * Creates a new output stream with the specified compressor, flush
 112      * mode and a default buffer size.
 113      *
 114      * @param out the output stream
 115      * @param def the compressor ("deflater")
 116      * @param syncFlush
 117      *        if {@code true} the {@link #flush()} method of this
 118      *        instance flushes the compressor with flush mode
 119      *        {@link Deflater#SYNC_FLUSH} before flushing the output
 120      *        stream, otherwise only flushes the output stream
 121      *
 122      * @since 1.7
 123      */
 124     public DeflaterOutputStream(OutputStream out,
 125                                 Deflater def,
 126                                 boolean syncFlush) {
 127         this(out, def, 512, syncFlush);
 128     }
 129 
 130 
 131     /**
 132      * Creates a new output stream with the specified compressor and
 133      * a default buffer size.
 134      *
 135      * <p>The new output stream instance is created as if by invoking
 136      * the 3-argument constructor DeflaterOutputStream(out, def, false).
 137      *
 138      * @param out the output stream
 139      * @param def the compressor ("deflater")
 140      */
 141     public DeflaterOutputStream(OutputStream out, Deflater def) {
 142         this(out, def, 512, false);
 143     }
 144 
 145     boolean usesDefaultDeflater = false;
 146 
 147 
 148     /**
 149      * Creates a new output stream with a default compressor, a default
 150      * buffer size and the specified flush mode.
 151      *
 152      * @param out the output stream
 153      * @param syncFlush
 154      *        if {@code true} the {@link #flush()} method of this
 155      *        instance flushes the compressor with flush mode
 156      *        {@link Deflater#SYNC_FLUSH} before flushing the output
 157      *        stream, otherwise only flushes the output stream
 158      *
 159      * @since 1.7
 160      */
 161     public DeflaterOutputStream(OutputStream out, boolean syncFlush) {
 162         this(out, new Deflater(), 512, syncFlush);
 163         usesDefaultDeflater = true;
 164     }
 165 
 166     /**
 167      * Creates a new output stream with a default compressor and buffer size.
 168      *
 169      * <p>The new output stream instance is created as if by invoking
 170      * the 2-argument constructor DeflaterOutputStream(out, false).
 171      *
 172      * @param out the output stream
 173      */
 174     public DeflaterOutputStream(OutputStream out) {
 175         this(out, false);
 176         usesDefaultDeflater = true;
 177     }
 178 
 179     /**
 180      * Writes a byte to the compressed output stream. This method will
 181      * block until the byte can be written.
 182      * @param b the byte to be written
 183      * @exception IOException if an I/O error has occurred
 184      */
 185     public void write(int b) throws IOException {
 186         byte[] buf = new byte[1];
 187         buf[0] = (byte)(b & 0xff);
 188         write(buf, 0, 1);
 189     }
 190 
 191     /**
 192      * Writes an array of bytes to the compressed output stream. This
 193      * method will block until all the bytes are written.
 194      * @param b the data to be written
 195      * @param off the start offset of the data
 196      * @param len the length of the data
 197      * @exception IOException if an I/O error has occurred
 198      */
 199     public void write(byte[] b, int off, int len) throws IOException {
 200         if (def.finished()) {
 201             throw new IOException("write beyond end of stream");
 202         }
 203         if ((off | len | (off + len) | (b.length - (off + len))) < 0) {
 204             throw new IndexOutOfBoundsException();
 205         } else if (len == 0) {
 206             return;
 207         }
 208         if (!def.finished()) {
 209             def.setInput(b, off, len);
 210             while (!def.needsInput()) {
 211                 deflate();
 212             }
 213         }
 214     }
 215 
 216     /**
 217      * Finishes writing compressed data to the output stream without closing
 218      * the underlying stream. Use this method when applying multiple filters
 219      * in succession to the same output stream.
 220      * @exception IOException if an I/O error has occurred
 221      */
 222     public void finish() throws IOException {
 223         if (!def.finished()) {
 224             def.finish();
 225             while (!def.finished()) {
 226                 deflate();
 227             }
 228         }
 229     }
 230 
 231     /**
 232      * Writes remaining compressed data to the output stream and closes the
 233      * underlying stream.
 234      * @exception IOException if an I/O error has occurred
 235      */
 236     public void close() throws IOException {
 237         if (!closed) {
 238             finish();
 239             if (usesDefaultDeflater)
 240                 def.end();
 241             out.close();
 242             closed = true;
 243         }
 244     }
 245 
 246     /**
 247      * Writes next block of compressed data to the output stream.
 248      * @throws IOException if an I/O error has occurred
 249      */
 250     protected void deflate() throws IOException {
 251         int len = def.deflate(buf, 0, buf.length);
 252         if (len > 0) {
 253             out.write(buf, 0, len);
 254         }
 255     }
 256 
 257     /**
 258      * Flushes the compressed output stream.
 259      *
 260      * If {@link #DeflaterOutputStream(OutputStream, Deflater, int, boolean)
 261      * syncFlush} is {@code true} when this compressed output stream is
 262      * constructed, this method first flushes the underlying {@code compressor}
 263      * with the flush mode {@link Deflater#SYNC_FLUSH} to force
 264      * all pending data to be flushed out to the output stream and then
 265      * flushes the output stream. Otherwise this method only flushes the
 266      * output stream without flushing the {@code compressor}.
 267      *
 268      * @throws IOException if an I/O error has occurred
 269      *
 270      * @since 1.7
 271      */
 272     public void flush() throws IOException {
 273         if (syncFlush && !def.finished()) {
 274             int len = 0;
 275             while ((len = def.deflate(buf, 0, buf.length, Deflater.SYNC_FLUSH)) > 0)
 276             {
 277                 out.write(buf, 0, len);
 278                 if (len < buf.length)
 279                     break;
 280             }
 281         }
 282         out.flush();
 283     }
 284 }
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