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Diffstat (limited to 'libjava/classpath/java/util/zip/Deflater.java')
| -rw-r--r-- | libjava/classpath/java/util/zip/Deflater.java | 537 |
1 files changed, 0 insertions, 537 deletions
diff --git a/libjava/classpath/java/util/zip/Deflater.java b/libjava/classpath/java/util/zip/Deflater.java deleted file mode 100644 index dd81fe7..0000000 --- a/libjava/classpath/java/util/zip/Deflater.java +++ /dev/null @@ -1,537 +0,0 @@ -/* Deflater.java - Compress a data stream - Copyright (C) 1999, 2000, 2001, 2004, 2005 Free Software Foundation, Inc. - -This file is part of GNU Classpath. - -GNU Classpath is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) -any later version. - -GNU Classpath is distributed in the hope that it will be useful, but -WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -General Public License for more details. - -You should have received a copy of the GNU General Public License -along with GNU Classpath; see the file COPYING. If not, write to the -Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301 USA. - -Linking this library statically or dynamically with other modules is -making a combined work based on this library. Thus, the terms and -conditions of the GNU General Public License cover the whole -combination. - -As a special exception, the copyright holders of this library give you -permission to link this library with independent modules to produce an -executable, regardless of the license terms of these independent -modules, and to copy and distribute the resulting executable under -terms of your choice, provided that you also meet, for each linked -independent module, the terms and conditions of the license of that -module. An independent module is a module which is not derived from -or based on this library. If you modify this library, you may extend -this exception to your version of the library, but you are not -obligated to do so. If you do not wish to do so, delete this -exception statement from your version. */ - -package java.util.zip; - -/** - * This is the Deflater class. The deflater class compresses input - * with the deflate algorithm described in RFC 1951. It has several - * compression levels and three different strategies described below. - * - * This class is <i>not</i> thread safe. This is inherent in the API, due - * to the split of deflate and setInput. - * - * @author Jochen Hoenicke - * @author Tom Tromey - */ -public class Deflater -{ - /** - * The best and slowest compression level. This tries to find very - * long and distant string repetitions. - */ - public static final int BEST_COMPRESSION = 9; - /** - * The worst but fastest compression level. - */ - public static final int BEST_SPEED = 1; - /** - * The default compression level. - */ - public static final int DEFAULT_COMPRESSION = -1; - /** - * This level won't compress at all but output uncompressed blocks. - */ - public static final int NO_COMPRESSION = 0; - - /** - * The default strategy. - */ - public static final int DEFAULT_STRATEGY = 0; - /** - * This strategy will only allow longer string repetitions. It is - * useful for random data with a small character set. - */ - public static final int FILTERED = 1; - - /** - * This strategy will not look for string repetitions at all. It - * only encodes with Huffman trees (which means, that more common - * characters get a smaller encoding. - */ - public static final int HUFFMAN_ONLY = 2; - - /** - * The compression method. This is the only method supported so far. - * There is no need to use this constant at all. - */ - public static final int DEFLATED = 8; - - /* - * The Deflater can do the following state transitions: - * - * (1) -> INIT_STATE ----> INIT_FINISHING_STATE ---. - * / | (2) (5) | - * / v (5) | - * (3)| SETDICT_STATE ---> SETDICT_FINISHING_STATE |(3) - * \ | (3) | ,-------' - * | | | (3) / - * v v (5) v v - * (1) -> BUSY_STATE ----> FINISHING_STATE - * | (6) - * v - * FINISHED_STATE - * \_____________________________________/ - * | (7) - * v - * CLOSED_STATE - * - * (1) If we should produce a header we start in INIT_STATE, otherwise - * we start in BUSY_STATE. - * (2) A dictionary may be set only when we are in INIT_STATE, then - * we change the state as indicated. - * (3) Whether a dictionary is set or not, on the first call of deflate - * we change to BUSY_STATE. - * (4) -- intentionally left blank -- :) - * (5) FINISHING_STATE is entered, when flush() is called to indicate that - * there is no more INPUT. There are also states indicating, that - * the header wasn't written yet. - * (6) FINISHED_STATE is entered, when everything has been flushed to the - * internal pending output buffer. - * (7) At any time (7) - * - */ - - private static final int IS_SETDICT = 0x01; - private static final int IS_FLUSHING = 0x04; - private static final int IS_FINISHING = 0x08; - - private static final int INIT_STATE = 0x00; - private static final int SETDICT_STATE = 0x01; - private static final int INIT_FINISHING_STATE = 0x08; - private static final int SETDICT_FINISHING_STATE = 0x09; - private static final int BUSY_STATE = 0x10; - private static final int FLUSHING_STATE = 0x14; - private static final int FINISHING_STATE = 0x1c; - private static final int FINISHED_STATE = 0x1e; - private static final int CLOSED_STATE = 0x7f; - - /** Compression level. */ - private int level; - - /** should we include a header. */ - private boolean noHeader; - - /** The current state. */ - private int state; - - /** The total bytes of output written. */ - private long totalOut; - - /** The pending output. */ - private DeflaterPending pending; - - /** The deflater engine. */ - private DeflaterEngine engine; - - /** - * Creates a new deflater with default compression level. - */ - public Deflater() - { - this(DEFAULT_COMPRESSION, false); - } - - /** - * Creates a new deflater with given compression level. - * @param lvl the compression level, a value between NO_COMPRESSION - * and BEST_COMPRESSION, or DEFAULT_COMPRESSION. - * @exception IllegalArgumentException if lvl is out of range. - */ - public Deflater(int lvl) - { - this(lvl, false); - } - - /** - * Creates a new deflater with given compression level. - * @param lvl the compression level, a value between NO_COMPRESSION - * and BEST_COMPRESSION. - * @param nowrap true, iff we should suppress the deflate header at the - * beginning and the adler checksum at the end of the output. This is - * useful for the GZIP format. - * @exception IllegalArgumentException if lvl is out of range. - */ - public Deflater(int lvl, boolean nowrap) - { - if (lvl == DEFAULT_COMPRESSION) - lvl = 6; - else if (lvl < NO_COMPRESSION || lvl > BEST_COMPRESSION) - throw new IllegalArgumentException(); - - pending = new DeflaterPending(); - engine = new DeflaterEngine(pending); - this.noHeader = nowrap; - setStrategy(DEFAULT_STRATEGY); - setLevel(lvl); - reset(); - } - - /** - * Resets the deflater. The deflater acts afterwards as if it was - * just created with the same compression level and strategy as it - * had before. - */ - public void reset() - { - state = (noHeader ? BUSY_STATE : INIT_STATE); - totalOut = 0; - pending.reset(); - engine.reset(); - } - - /** - * Frees all objects allocated by the compressor. There's no - * reason to call this, since you can just rely on garbage - * collection. Exists only for compatibility against Sun's JDK, - * where the compressor allocates native memory. - * If you call any method (even reset) afterwards the behaviour is - * <i>undefined</i>. - */ - public void end() - { - engine = null; - pending = null; - state = CLOSED_STATE; - } - - /** - * Gets the current adler checksum of the data that was processed so - * far. - */ - public int getAdler() - { - return engine.getAdler(); - } - - /** - * Gets the number of input bytes processed so far. - */ - public int getTotalIn() - { - return (int) engine.getTotalIn(); - } - - /** - * Gets the number of input bytes processed so far. - * @since 1.5 - */ - public long getBytesRead() - { - return engine.getTotalIn(); - } - - /** - * Gets the number of output bytes so far. - */ - public int getTotalOut() - { - return (int) totalOut; - } - - /** - * Gets the number of output bytes so far. - * @since 1.5 - */ - public long getBytesWritten() - { - return totalOut; - } - - /** - * Finalizes this object. - */ - protected void finalize() - { - /* Exists solely for compatibility. We don't have any native state. */ - } - - /** - * Flushes the current input block. Further calls to deflate() will - * produce enough output to inflate everything in the current input - * block. This is not part of Sun's JDK so I have made it package - * private. It is used by DeflaterOutputStream to implement - * flush(). - */ - void flush() { - state |= IS_FLUSHING; - } - - /** - * Finishes the deflater with the current input block. It is an error - * to give more input after this method was called. This method must - * be called to force all bytes to be flushed. - */ - public void finish() { - state |= IS_FLUSHING | IS_FINISHING; - } - - /** - * Returns true iff the stream was finished and no more output bytes - * are available. - */ - public boolean finished() - { - return state == FINISHED_STATE && pending.isFlushed(); - } - - /** - * Returns true, if the input buffer is empty. - * You should then call setInput(). <br> - * - * <em>NOTE</em>: This method can also return true when the stream - * was finished. - */ - public boolean needsInput() - { - return engine.needsInput(); - } - - /** - * Sets the data which should be compressed next. This should be only - * called when needsInput indicates that more input is needed. - * If you call setInput when needsInput() returns false, the - * previous input that is still pending will be thrown away. - * The given byte array should not be changed, before needsInput() returns - * true again. - * This call is equivalent to <code>setInput(input, 0, input.length)</code>. - * @param input the buffer containing the input data. - * @exception IllegalStateException if the buffer was finished() or ended(). - */ - public void setInput(byte[] input) - { - setInput(input, 0, input.length); - } - - /** - * Sets the data which should be compressed next. This should be - * only called when needsInput indicates that more input is needed. - * The given byte array should not be changed, before needsInput() returns - * true again. - * @param input the buffer containing the input data. - * @param off the start of the data. - * @param len the length of the data. - * @exception IllegalStateException if the buffer was finished() or ended() - * or if previous input is still pending. - */ - public void setInput(byte[] input, int off, int len) - { - if ((state & IS_FINISHING) != 0) - throw new IllegalStateException("finish()/end() already called"); - engine.setInput(input, off, len); - } - - /** - * Sets the compression level. There is no guarantee of the exact - * position of the change, but if you call this when needsInput is - * true the change of compression level will occur somewhere near - * before the end of the so far given input. - * @param lvl the new compression level. - */ - public void setLevel(int lvl) - { - if (lvl == DEFAULT_COMPRESSION) - lvl = 6; - else if (lvl < NO_COMPRESSION || lvl > BEST_COMPRESSION) - throw new IllegalArgumentException(); - - - if (level != lvl) - { - level = lvl; - engine.setLevel(lvl); - } - } - - /** - * Sets the compression strategy. Strategy is one of - * DEFAULT_STRATEGY, HUFFMAN_ONLY and FILTERED. For the exact - * position where the strategy is changed, the same as for - * setLevel() applies. - * @param stgy the new compression strategy. - */ - public void setStrategy(int stgy) - { - if (stgy != DEFAULT_STRATEGY && stgy != FILTERED - && stgy != HUFFMAN_ONLY) - throw new IllegalArgumentException(); - engine.setStrategy(stgy); - } - - /** - * Deflates the current input block to the given array. It returns - * the number of bytes compressed, or 0 if either - * needsInput() or finished() returns true or length is zero. - * @param output the buffer where to write the compressed data. - */ - public int deflate(byte[] output) - { - return deflate(output, 0, output.length); - } - - /** - * Deflates the current input block to the given array. It returns - * the number of bytes compressed, or 0 if either - * needsInput() or finished() returns true or length is zero. - * @param output the buffer where to write the compressed data. - * @param offset the offset into the output array. - * @param length the maximum number of bytes that may be written. - * @exception IllegalStateException if end() was called. - * @exception IndexOutOfBoundsException if offset and/or length - * don't match the array length. - */ - public int deflate(byte[] output, int offset, int length) - { - int origLength = length; - - if (state == CLOSED_STATE) - throw new IllegalStateException("Deflater closed"); - - if (state < BUSY_STATE) - { - /* output header */ - int header = (DEFLATED + - ((DeflaterConstants.MAX_WBITS - 8) << 4)) << 8; - int level_flags = (level - 1) >> 1; - if (level_flags < 0 || level_flags > 3) - level_flags = 3; - header |= level_flags << 6; - if ((state & IS_SETDICT) != 0) - /* Dictionary was set */ - header |= DeflaterConstants.PRESET_DICT; - header += 31 - (header % 31); - - pending.writeShortMSB(header); - if ((state & IS_SETDICT) != 0) - { - int chksum = engine.getAdler(); - engine.resetAdler(); - pending.writeShortMSB(chksum >> 16); - pending.writeShortMSB(chksum & 0xffff); - } - - state = BUSY_STATE | (state & (IS_FLUSHING | IS_FINISHING)); - } - - for (;;) - { - int count = pending.flush(output, offset, length); - offset += count; - totalOut += count; - length -= count; - if (length == 0 || state == FINISHED_STATE) - break; - - if (!engine.deflate((state & IS_FLUSHING) != 0, - (state & IS_FINISHING) != 0)) - { - if (state == BUSY_STATE) - /* We need more input now */ - return origLength - length; - else if (state == FLUSHING_STATE) - { - if (level != NO_COMPRESSION) - { - /* We have to supply some lookahead. 8 bit lookahead - * are needed by the zlib inflater, and we must fill - * the next byte, so that all bits are flushed. - */ - int neededbits = 8 + ((-pending.getBitCount()) & 7); - while (neededbits > 0) - { - /* write a static tree block consisting solely of - * an EOF: - */ - pending.writeBits(2, 10); - neededbits -= 10; - } - } - state = BUSY_STATE; - } - else if (state == FINISHING_STATE) - { - pending.alignToByte(); - /* We have completed the stream */ - if (!noHeader) - { - int adler = engine.getAdler(); - pending.writeShortMSB(adler >> 16); - pending.writeShortMSB(adler & 0xffff); - } - state = FINISHED_STATE; - } - } - } - - return origLength - length; - } - - /** - * Sets the dictionary which should be used in the deflate process. - * This call is equivalent to <code>setDictionary(dict, 0, - * dict.length)</code>. - * @param dict the dictionary. - * @exception IllegalStateException if setInput () or deflate () - * were already called or another dictionary was already set. - */ - public void setDictionary(byte[] dict) - { - setDictionary(dict, 0, dict.length); - } - - /** - * Sets the dictionary which should be used in the deflate process. - * The dictionary should be a byte array containing strings that are - * likely to occur in the data which should be compressed. The - * dictionary is not stored in the compressed output, only a - * checksum. To decompress the output you need to supply the same - * dictionary again. - * @param dict the dictionary. - * @param offset an offset into the dictionary. - * @param length the length of the dictionary. - * @exception IllegalStateException if setInput () or deflate () were - * already called or another dictionary was already set. - */ - public void setDictionary(byte[] dict, int offset, int length) - { - if (state != INIT_STATE) - throw new IllegalStateException(); - - state = SETDICT_STATE; - engine.setDictionary(dict, offset, length); - } -} |