mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-13 18:34:45 +00:00
699 lines
20 KiB
Java
699 lines
20 KiB
Java
|
/* DeflaterEngine.java --
|
||
|
Copyright (C) 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;
|
||
|
|
||
|
class DeflaterEngine implements DeflaterConstants
|
||
|
{
|
||
|
private static final int TOO_FAR = 4096;
|
||
|
|
||
|
private int ins_h;
|
||
|
|
||
|
/**
|
||
|
* Hashtable, hashing three characters to an index for window, so
|
||
|
* that window[index]..window[index+2] have this hash code.
|
||
|
* Note that the array should really be unsigned short, so you need
|
||
|
* to and the values with 0xffff.
|
||
|
*/
|
||
|
private short[] head;
|
||
|
|
||
|
/**
|
||
|
* prev[index & WMASK] points to the previous index that has the
|
||
|
* same hash code as the string starting at index. This way
|
||
|
* entries with the same hash code are in a linked list.
|
||
|
* Note that the array should really be unsigned short, so you need
|
||
|
* to and the values with 0xffff.
|
||
|
*/
|
||
|
private short[] prev;
|
||
|
|
||
|
private int matchStart, matchLen;
|
||
|
private boolean prevAvailable;
|
||
|
private int blockStart;
|
||
|
|
||
|
/**
|
||
|
* strstart points to the current character in window.
|
||
|
*/
|
||
|
private int strstart;
|
||
|
|
||
|
/**
|
||
|
* lookahead is the number of characters starting at strstart in
|
||
|
* window that are valid.
|
||
|
* So window[strstart] until window[strstart+lookahead-1] are valid
|
||
|
* characters.
|
||
|
*/
|
||
|
private int lookahead;
|
||
|
|
||
|
/**
|
||
|
* This array contains the part of the uncompressed stream that
|
||
|
* is of relevance. The current character is indexed by strstart.
|
||
|
*/
|
||
|
private byte[] window;
|
||
|
|
||
|
private int strategy, max_chain, max_lazy, niceLength, goodLength;
|
||
|
|
||
|
/** The current compression function. */
|
||
|
private int comprFunc;
|
||
|
|
||
|
/** The input data for compression. */
|
||
|
private byte[] inputBuf;
|
||
|
|
||
|
/** The total bytes of input read. */
|
||
|
private long totalIn;
|
||
|
|
||
|
/** The offset into inputBuf, where input data starts. */
|
||
|
private int inputOff;
|
||
|
|
||
|
/** The end offset of the input data. */
|
||
|
private int inputEnd;
|
||
|
|
||
|
private DeflaterPending pending;
|
||
|
private DeflaterHuffman huffman;
|
||
|
|
||
|
/** The adler checksum */
|
||
|
private Adler32 adler;
|
||
|
|
||
|
/* DEFLATE ALGORITHM:
|
||
|
*
|
||
|
* The uncompressed stream is inserted into the window array. When
|
||
|
* the window array is full the first half is thrown away and the
|
||
|
* second half is copied to the beginning.
|
||
|
*
|
||
|
* The head array is a hash table. Three characters build a hash value
|
||
|
* and they the value points to the corresponding index in window of
|
||
|
* the last string with this hash. The prev array implements a
|
||
|
* linked list of matches with the same hash: prev[index & WMASK] points
|
||
|
* to the previous index with the same hash.
|
||
|
*
|
||
|
*
|
||
|
*/
|
||
|
|
||
|
|
||
|
DeflaterEngine(DeflaterPending pending) {
|
||
|
this.pending = pending;
|
||
|
huffman = new DeflaterHuffman(pending);
|
||
|
adler = new Adler32();
|
||
|
|
||
|
window = new byte[2*WSIZE];
|
||
|
head = new short[HASH_SIZE];
|
||
|
prev = new short[WSIZE];
|
||
|
|
||
|
/* We start at index 1, to avoid a implementation deficiency, that
|
||
|
* we cannot build a repeat pattern at index 0.
|
||
|
*/
|
||
|
blockStart = strstart = 1;
|
||
|
}
|
||
|
|
||
|
public void reset()
|
||
|
{
|
||
|
huffman.reset();
|
||
|
adler.reset();
|
||
|
blockStart = strstart = 1;
|
||
|
lookahead = 0;
|
||
|
totalIn = 0;
|
||
|
prevAvailable = false;
|
||
|
matchLen = MIN_MATCH - 1;
|
||
|
for (int i = 0; i < HASH_SIZE; i++)
|
||
|
head[i] = 0;
|
||
|
for (int i = 0; i < WSIZE; i++)
|
||
|
prev[i] = 0;
|
||
|
}
|
||
|
|
||
|
public final void resetAdler()
|
||
|
{
|
||
|
adler.reset();
|
||
|
}
|
||
|
|
||
|
public final int getAdler()
|
||
|
{
|
||
|
int chksum = (int) adler.getValue();
|
||
|
return chksum;
|
||
|
}
|
||
|
|
||
|
public final long getTotalIn()
|
||
|
{
|
||
|
return totalIn;
|
||
|
}
|
||
|
|
||
|
public final void setStrategy(int strat)
|
||
|
{
|
||
|
strategy = strat;
|
||
|
}
|
||
|
|
||
|
public void setLevel(int lvl)
|
||
|
{
|
||
|
goodLength = DeflaterConstants.GOOD_LENGTH[lvl];
|
||
|
max_lazy = DeflaterConstants.MAX_LAZY[lvl];
|
||
|
niceLength = DeflaterConstants.NICE_LENGTH[lvl];
|
||
|
max_chain = DeflaterConstants.MAX_CHAIN[lvl];
|
||
|
|
||
|
if (DeflaterConstants.COMPR_FUNC[lvl] != comprFunc)
|
||
|
{
|
||
|
if (DeflaterConstants.DEBUGGING)
|
||
|
System.err.println("Change from "+comprFunc +" to "
|
||
|
+ DeflaterConstants.COMPR_FUNC[lvl]);
|
||
|
switch (comprFunc)
|
||
|
{
|
||
|
case DEFLATE_STORED:
|
||
|
if (strstart > blockStart)
|
||
|
{
|
||
|
huffman.flushStoredBlock(window, blockStart,
|
||
|
strstart - blockStart, false);
|
||
|
blockStart = strstart;
|
||
|
}
|
||
|
updateHash();
|
||
|
break;
|
||
|
case DEFLATE_FAST:
|
||
|
if (strstart > blockStart)
|
||
|
{
|
||
|
huffman.flushBlock(window, blockStart, strstart - blockStart,
|
||
|
false);
|
||
|
blockStart = strstart;
|
||
|
}
|
||
|
break;
|
||
|
case DEFLATE_SLOW:
|
||
|
if (prevAvailable)
|
||
|
huffman.tallyLit(window[strstart-1] & 0xff);
|
||
|
if (strstart > blockStart)
|
||
|
{
|
||
|
huffman.flushBlock(window, blockStart, strstart - blockStart,
|
||
|
false);
|
||
|
blockStart = strstart;
|
||
|
}
|
||
|
prevAvailable = false;
|
||
|
matchLen = MIN_MATCH - 1;
|
||
|
break;
|
||
|
}
|
||
|
comprFunc = COMPR_FUNC[lvl];
|
||
|
}
|
||
|
}
|
||
|
|
||
|
private void updateHash() {
|
||
|
if (DEBUGGING)
|
||
|
System.err.println("updateHash: "+strstart);
|
||
|
ins_h = (window[strstart] << HASH_SHIFT) ^ window[strstart + 1];
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Inserts the current string in the head hash and returns the previous
|
||
|
* value for this hash.
|
||
|
*/
|
||
|
private int insertString() {
|
||
|
short match;
|
||
|
int hash = ((ins_h << HASH_SHIFT) ^ window[strstart + (MIN_MATCH -1)])
|
||
|
& HASH_MASK;
|
||
|
|
||
|
if (DEBUGGING)
|
||
|
{
|
||
|
if (hash != (((window[strstart] << (2*HASH_SHIFT))
|
||
|
^ (window[strstart + 1] << HASH_SHIFT)
|
||
|
^ (window[strstart + 2])) & HASH_MASK))
|
||
|
throw new InternalError("hash inconsistent: "+hash+"/"
|
||
|
+window[strstart]+","
|
||
|
+window[strstart+1]+","
|
||
|
+window[strstart+2]+","+HASH_SHIFT);
|
||
|
}
|
||
|
|
||
|
prev[strstart & WMASK] = match = head[hash];
|
||
|
head[hash] = (short) strstart;
|
||
|
ins_h = hash;
|
||
|
return match & 0xffff;
|
||
|
}
|
||
|
|
||
|
private void slideWindow()
|
||
|
{
|
||
|
System.arraycopy(window, WSIZE, window, 0, WSIZE);
|
||
|
matchStart -= WSIZE;
|
||
|
strstart -= WSIZE;
|
||
|
blockStart -= WSIZE;
|
||
|
|
||
|
/* Slide the hash table (could be avoided with 32 bit values
|
||
|
* at the expense of memory usage).
|
||
|
*/
|
||
|
for (int i = 0; i < HASH_SIZE; i++)
|
||
|
{
|
||
|
int m = head[i] & 0xffff;
|
||
|
head[i] = m >= WSIZE ? (short) (m - WSIZE) : 0;
|
||
|
}
|
||
|
|
||
|
/* Slide the prev table.
|
||
|
*/
|
||
|
for (int i = 0; i < WSIZE; i++)
|
||
|
{
|
||
|
int m = prev[i] & 0xffff;
|
||
|
prev[i] = m >= WSIZE ? (short) (m - WSIZE) : 0;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Fill the window when the lookahead becomes insufficient.
|
||
|
* Updates strstart and lookahead.
|
||
|
*
|
||
|
* OUT assertions: strstart + lookahead <= 2*WSIZE
|
||
|
* lookahead >= MIN_LOOKAHEAD or inputOff == inputEnd
|
||
|
*/
|
||
|
private void fillWindow()
|
||
|
{
|
||
|
/* If the window is almost full and there is insufficient lookahead,
|
||
|
* move the upper half to the lower one to make room in the upper half.
|
||
|
*/
|
||
|
if (strstart >= WSIZE + MAX_DIST)
|
||
|
slideWindow();
|
||
|
|
||
|
/* If there is not enough lookahead, but still some input left,
|
||
|
* read in the input
|
||
|
*/
|
||
|
while (lookahead < DeflaterConstants.MIN_LOOKAHEAD && inputOff < inputEnd)
|
||
|
{
|
||
|
int more = 2*WSIZE - lookahead - strstart;
|
||
|
|
||
|
if (more > inputEnd - inputOff)
|
||
|
more = inputEnd - inputOff;
|
||
|
|
||
|
System.arraycopy(inputBuf, inputOff,
|
||
|
window, strstart + lookahead, more);
|
||
|
adler.update(inputBuf, inputOff, more);
|
||
|
inputOff += more;
|
||
|
totalIn += more;
|
||
|
lookahead += more;
|
||
|
}
|
||
|
|
||
|
if (lookahead >= MIN_MATCH)
|
||
|
updateHash();
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Find the best (longest) string in the window matching the
|
||
|
* string starting at strstart.
|
||
|
*
|
||
|
* Preconditions:
|
||
|
* strstart + MAX_MATCH <= window.length.
|
||
|
*
|
||
|
*
|
||
|
* @param curMatch
|
||
|
*/
|
||
|
private boolean findLongestMatch(int curMatch) {
|
||
|
int chainLength = this.max_chain;
|
||
|
int niceLength = this.niceLength;
|
||
|
short[] prev = this.prev;
|
||
|
int scan = this.strstart;
|
||
|
int match;
|
||
|
int best_end = this.strstart + matchLen;
|
||
|
int best_len = Math.max(matchLen, MIN_MATCH - 1);
|
||
|
|
||
|
int limit = Math.max(strstart - MAX_DIST, 0);
|
||
|
|
||
|
int strend = scan + MAX_MATCH - 1;
|
||
|
byte scan_end1 = window[best_end - 1];
|
||
|
byte scan_end = window[best_end];
|
||
|
|
||
|
/* Do not waste too much time if we already have a good match: */
|
||
|
if (best_len >= this.goodLength)
|
||
|
chainLength >>= 2;
|
||
|
|
||
|
/* Do not look for matches beyond the end of the input. This is necessary
|
||
|
* to make deflate deterministic.
|
||
|
*/
|
||
|
if (niceLength > lookahead)
|
||
|
niceLength = lookahead;
|
||
|
|
||
|
if (DeflaterConstants.DEBUGGING
|
||
|
&& strstart > 2*WSIZE - MIN_LOOKAHEAD)
|
||
|
throw new InternalError("need lookahead");
|
||
|
|
||
|
do {
|
||
|
if (DeflaterConstants.DEBUGGING && curMatch >= strstart)
|
||
|
throw new InternalError("future match");
|
||
|
if (window[curMatch + best_len] != scan_end
|
||
|
|| window[curMatch + best_len - 1] != scan_end1
|
||
|
|| window[curMatch] != window[scan]
|
||
|
|| window[curMatch+1] != window[scan + 1])
|
||
|
continue;
|
||
|
|
||
|
match = curMatch + 2;
|
||
|
scan += 2;
|
||
|
|
||
|
/* We check for insufficient lookahead only every 8th comparison;
|
||
|
* the 256th check will be made at strstart+258.
|
||
|
*/
|
||
|
while (window[++scan] == window[++match]
|
||
|
&& window[++scan] == window[++match]
|
||
|
&& window[++scan] == window[++match]
|
||
|
&& window[++scan] == window[++match]
|
||
|
&& window[++scan] == window[++match]
|
||
|
&& window[++scan] == window[++match]
|
||
|
&& window[++scan] == window[++match]
|
||
|
&& window[++scan] == window[++match]
|
||
|
&& scan < strend)
|
||
|
;
|
||
|
|
||
|
if (scan > best_end) {
|
||
|
// if (DeflaterConstants.DEBUGGING && ins_h == 0)
|
||
|
// System.err.println("Found match: "+curMatch+"-"+(scan-strstart));
|
||
|
matchStart = curMatch;
|
||
|
best_end = scan;
|
||
|
best_len = scan - strstart;
|
||
|
if (best_len >= niceLength)
|
||
|
break;
|
||
|
|
||
|
scan_end1 = window[best_end-1];
|
||
|
scan_end = window[best_end];
|
||
|
}
|
||
|
scan = strstart;
|
||
|
} while ((curMatch = (prev[curMatch & WMASK] & 0xffff)) > limit
|
||
|
&& --chainLength != 0);
|
||
|
|
||
|
matchLen = Math.min(best_len, lookahead);
|
||
|
return matchLen >= MIN_MATCH;
|
||
|
}
|
||
|
|
||
|
void setDictionary(byte[] buffer, int offset, int length) {
|
||
|
if (DeflaterConstants.DEBUGGING && strstart != 1)
|
||
|
throw new IllegalStateException("strstart not 1");
|
||
|
adler.update(buffer, offset, length);
|
||
|
if (length < MIN_MATCH)
|
||
|
return;
|
||
|
if (length > MAX_DIST) {
|
||
|
offset += length - MAX_DIST;
|
||
|
length = MAX_DIST;
|
||
|
}
|
||
|
|
||
|
System.arraycopy(buffer, offset, window, strstart, length);
|
||
|
|
||
|
updateHash();
|
||
|
length--;
|
||
|
while (--length > 0)
|
||
|
{
|
||
|
insertString();
|
||
|
strstart++;
|
||
|
}
|
||
|
strstart += 2;
|
||
|
blockStart = strstart;
|
||
|
}
|
||
|
|
||
|
private boolean deflateStored(boolean flush, boolean finish)
|
||
|
{
|
||
|
if (!flush && lookahead == 0)
|
||
|
return false;
|
||
|
|
||
|
strstart += lookahead;
|
||
|
lookahead = 0;
|
||
|
|
||
|
int storedLen = strstart - blockStart;
|
||
|
|
||
|
if ((storedLen >= DeflaterConstants.MAX_BLOCK_SIZE)
|
||
|
/* Block is full */
|
||
|
|| (blockStart < WSIZE && storedLen >= MAX_DIST)
|
||
|
/* Block may move out of window */
|
||
|
|| flush)
|
||
|
{
|
||
|
boolean lastBlock = finish;
|
||
|
if (storedLen > DeflaterConstants.MAX_BLOCK_SIZE)
|
||
|
{
|
||
|
storedLen = DeflaterConstants.MAX_BLOCK_SIZE;
|
||
|
lastBlock = false;
|
||
|
}
|
||
|
|
||
|
if (DeflaterConstants.DEBUGGING)
|
||
|
System.err.println("storedBlock["+storedLen+","+lastBlock+"]");
|
||
|
|
||
|
huffman.flushStoredBlock(window, blockStart, storedLen, lastBlock);
|
||
|
blockStart += storedLen;
|
||
|
return !lastBlock;
|
||
|
}
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
private boolean deflateFast(boolean flush, boolean finish)
|
||
|
{
|
||
|
if (lookahead < MIN_LOOKAHEAD && !flush)
|
||
|
return false;
|
||
|
|
||
|
while (lookahead >= MIN_LOOKAHEAD || flush)
|
||
|
{
|
||
|
if (lookahead == 0)
|
||
|
{
|
||
|
/* We are flushing everything */
|
||
|
huffman.flushBlock(window, blockStart, strstart - blockStart,
|
||
|
finish);
|
||
|
blockStart = strstart;
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
if (strstart > 2 * WSIZE - MIN_LOOKAHEAD)
|
||
|
{
|
||
|
/* slide window, as findLongestMatch need this.
|
||
|
* This should only happen when flushing and the window
|
||
|
* is almost full.
|
||
|
*/
|
||
|
slideWindow();
|
||
|
}
|
||
|
|
||
|
int hashHead;
|
||
|
if (lookahead >= MIN_MATCH
|
||
|
&& (hashHead = insertString()) != 0
|
||
|
&& strategy != Deflater.HUFFMAN_ONLY
|
||
|
&& strstart - hashHead <= MAX_DIST
|
||
|
&& findLongestMatch(hashHead))
|
||
|
{
|
||
|
/* longestMatch sets matchStart and matchLen */
|
||
|
if (DeflaterConstants.DEBUGGING)
|
||
|
{
|
||
|
for (int i = 0 ; i < matchLen; i++)
|
||
|
{
|
||
|
if (window[strstart+i] != window[matchStart + i])
|
||
|
throw new InternalError();
|
||
|
}
|
||
|
}
|
||
|
boolean full = huffman.tallyDist(strstart - matchStart, matchLen);
|
||
|
|
||
|
lookahead -= matchLen;
|
||
|
if (matchLen <= max_lazy && lookahead >= MIN_MATCH)
|
||
|
{
|
||
|
while (--matchLen > 0)
|
||
|
{
|
||
|
strstart++;
|
||
|
insertString();
|
||
|
}
|
||
|
strstart++;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
strstart += matchLen;
|
||
|
if (lookahead >= MIN_MATCH - 1)
|
||
|
updateHash();
|
||
|
}
|
||
|
matchLen = MIN_MATCH - 1;
|
||
|
if (!full)
|
||
|
continue;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
/* No match found */
|
||
|
huffman.tallyLit(window[strstart] & 0xff);
|
||
|
strstart++;
|
||
|
lookahead--;
|
||
|
}
|
||
|
|
||
|
if (huffman.isFull())
|
||
|
{
|
||
|
boolean lastBlock = finish && lookahead == 0;
|
||
|
huffman.flushBlock(window, blockStart, strstart - blockStart,
|
||
|
lastBlock);
|
||
|
blockStart = strstart;
|
||
|
return !lastBlock;
|
||
|
}
|
||
|
}
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
private boolean deflateSlow(boolean flush, boolean finish)
|
||
|
{
|
||
|
if (lookahead < MIN_LOOKAHEAD && !flush)
|
||
|
return false;
|
||
|
|
||
|
while (lookahead >= MIN_LOOKAHEAD || flush)
|
||
|
{
|
||
|
if (lookahead == 0)
|
||
|
{
|
||
|
if (prevAvailable)
|
||
|
huffman.tallyLit(window[strstart-1] & 0xff);
|
||
|
prevAvailable = false;
|
||
|
|
||
|
/* We are flushing everything */
|
||
|
if (DeflaterConstants.DEBUGGING && !flush)
|
||
|
throw new InternalError("Not flushing, but no lookahead");
|
||
|
huffman.flushBlock(window, blockStart, strstart - blockStart,
|
||
|
finish);
|
||
|
blockStart = strstart;
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
if (strstart >= 2 * WSIZE - MIN_LOOKAHEAD)
|
||
|
{
|
||
|
/* slide window, as findLongestMatch need this.
|
||
|
* This should only happen when flushing and the window
|
||
|
* is almost full.
|
||
|
*/
|
||
|
slideWindow();
|
||
|
}
|
||
|
|
||
|
int prevMatch = matchStart;
|
||
|
int prevLen = matchLen;
|
||
|
if (lookahead >= MIN_MATCH)
|
||
|
{
|
||
|
int hashHead = insertString();
|
||
|
if (strategy != Deflater.HUFFMAN_ONLY
|
||
|
&& hashHead != 0 && strstart - hashHead <= MAX_DIST
|
||
|
&& findLongestMatch(hashHead))
|
||
|
{
|
||
|
/* longestMatch sets matchStart and matchLen */
|
||
|
|
||
|
/* Discard match if too small and too far away */
|
||
|
if (matchLen <= 5
|
||
|
&& (strategy == Deflater.FILTERED
|
||
|
|| (matchLen == MIN_MATCH
|
||
|
&& strstart - matchStart > TOO_FAR))) {
|
||
|
matchLen = MIN_MATCH - 1;
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* previous match was better */
|
||
|
if (prevLen >= MIN_MATCH && matchLen <= prevLen)
|
||
|
{
|
||
|
if (DeflaterConstants.DEBUGGING)
|
||
|
{
|
||
|
for (int i = 0 ; i < matchLen; i++)
|
||
|
{
|
||
|
if (window[strstart-1+i] != window[prevMatch + i])
|
||
|
throw new InternalError();
|
||
|
}
|
||
|
}
|
||
|
huffman.tallyDist(strstart - 1 - prevMatch, prevLen);
|
||
|
prevLen -= 2;
|
||
|
do
|
||
|
{
|
||
|
strstart++;
|
||
|
lookahead--;
|
||
|
if (lookahead >= MIN_MATCH)
|
||
|
insertString();
|
||
|
}
|
||
|
while (--prevLen > 0);
|
||
|
strstart ++;
|
||
|
lookahead--;
|
||
|
prevAvailable = false;
|
||
|
matchLen = MIN_MATCH - 1;
|
||
|
}
|
||
|
else
|
||
|
{
|
||
|
if (prevAvailable)
|
||
|
huffman.tallyLit(window[strstart-1] & 0xff);
|
||
|
prevAvailable = true;
|
||
|
strstart++;
|
||
|
lookahead--;
|
||
|
}
|
||
|
|
||
|
if (huffman.isFull())
|
||
|
{
|
||
|
int len = strstart - blockStart;
|
||
|
if (prevAvailable)
|
||
|
len--;
|
||
|
boolean lastBlock = (finish && lookahead == 0 && !prevAvailable);
|
||
|
huffman.flushBlock(window, blockStart, len, lastBlock);
|
||
|
blockStart += len;
|
||
|
return !lastBlock;
|
||
|
}
|
||
|
}
|
||
|
return true;
|
||
|
}
|
||
|
|
||
|
public boolean deflate(boolean flush, boolean finish)
|
||
|
{
|
||
|
boolean progress;
|
||
|
do
|
||
|
{
|
||
|
fillWindow();
|
||
|
boolean canFlush = flush && inputOff == inputEnd;
|
||
|
if (DeflaterConstants.DEBUGGING)
|
||
|
System.err.println("window: ["+blockStart+","+strstart+","
|
||
|
+lookahead+"], "+comprFunc+","+canFlush);
|
||
|
switch (comprFunc)
|
||
|
{
|
||
|
case DEFLATE_STORED:
|
||
|
progress = deflateStored(canFlush, finish);
|
||
|
break;
|
||
|
case DEFLATE_FAST:
|
||
|
progress = deflateFast(canFlush, finish);
|
||
|
break;
|
||
|
case DEFLATE_SLOW:
|
||
|
progress = deflateSlow(canFlush, finish);
|
||
|
break;
|
||
|
default:
|
||
|
throw new InternalError();
|
||
|
}
|
||
|
}
|
||
|
while (pending.isFlushed() /* repeat while we have no pending output */
|
||
|
&& progress); /* and progress was made */
|
||
|
|
||
|
return progress;
|
||
|
}
|
||
|
|
||
|
public void setInput(byte[] buf, int off, int len)
|
||
|
{
|
||
|
if (inputOff < inputEnd)
|
||
|
throw new IllegalStateException
|
||
|
("Old input was not completely processed");
|
||
|
|
||
|
int end = off + len;
|
||
|
|
||
|
/* We want to throw an ArrayIndexOutOfBoundsException early. The
|
||
|
* check is very tricky: it also handles integer wrap around.
|
||
|
*/
|
||
|
if (0 > off || off > end || end > buf.length)
|
||
|
throw new ArrayIndexOutOfBoundsException();
|
||
|
|
||
|
inputBuf = buf;
|
||
|
inputOff = off;
|
||
|
inputEnd = end;
|
||
|
}
|
||
|
|
||
|
public final boolean needsInput()
|
||
|
{
|
||
|
return inputEnd == inputOff;
|
||
|
}
|
||
|
}
|