diff app/src/main/java/com/jcraft/jzlib/Deflate.java @ 438:d29cce60f393

migrate from Eclipse to Android Studio
author Carl Byington <carl@five-ten-sg.com>
date Thu, 03 Dec 2015 11:23:55 -0800
parents src/com/jcraft/jzlib/Deflate.java@46c2115ae1c8
children
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/src/main/java/com/jcraft/jzlib/Deflate.java	Thu Dec 03 11:23:55 2015 -0800
@@ -0,0 +1,1757 @@
+/* -*-mode:java; c-basic-offset:2; -*- */
+/*
+Copyright (c) 2000-2011 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.
+ */
+/*
+ * This program is based on zlib-1.1.3, so all credit should go authors
+ * Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu)
+ * and contributors of zlib.
+ */
+
+package com.jcraft.jzlib;
+
+public 
+final class Deflate implements Cloneable {
+
+  static final private int MAX_MEM_LEVEL=9;
+
+  static final private int Z_DEFAULT_COMPRESSION=-1;
+
+  static final private int MAX_WBITS=15;            // 32K LZ77 window
+  static final private int DEF_MEM_LEVEL=8;
+
+  static class Config{
+    int good_length; // reduce lazy search above this match length
+    int max_lazy;    // do not perform lazy search above this match length
+    int nice_length; // quit search above this match length
+    int max_chain;
+    int func;
+    Config(int good_length, int max_lazy, 
+	   int nice_length, int max_chain, int func){
+      this.good_length=good_length;
+      this.max_lazy=max_lazy;
+      this.nice_length=nice_length;
+      this.max_chain=max_chain;
+      this.func=func;
+    }
+  }
+  
+  static final private int STORED=0;
+  static final private int FAST=1;
+  static final private int SLOW=2;
+  static final private Config[] config_table;    
+  static{
+    config_table=new Config[10];
+    //                         good  lazy  nice  chain
+    config_table[0]=new Config(0,    0,    0,    0, STORED);
+    config_table[1]=new Config(4,    4,    8,    4, FAST);
+    config_table[2]=new Config(4,    5,   16,    8, FAST);
+    config_table[3]=new Config(4,    6,   32,   32, FAST);
+
+    config_table[4]=new Config(4,    4,   16,   16, SLOW);
+    config_table[5]=new Config(8,   16,   32,   32, SLOW);
+    config_table[6]=new Config(8,   16,  128,  128, SLOW);
+    config_table[7]=new Config(8,   32,  128,  256, SLOW);
+    config_table[8]=new Config(32, 128,  258, 1024, SLOW);
+    config_table[9]=new Config(32, 258,  258, 4096, SLOW);
+  }
+
+  static final private String[] z_errmsg = {
+    "need dictionary",     // Z_NEED_DICT       2
+    "stream end",          // Z_STREAM_END      1
+    "",                    // Z_OK              0
+    "file error",          // Z_ERRNO         (-1)
+    "stream error",        // Z_STREAM_ERROR  (-2)
+    "data error",          // Z_DATA_ERROR    (-3)
+    "insufficient memory", // Z_MEM_ERROR     (-4)
+    "buffer error",        // Z_BUF_ERROR     (-5)
+    "incompatible version",// Z_VERSION_ERROR (-6)
+    ""
+  };
+
+  // block not completed, need more input or more output
+  static final private int NeedMore=0; 
+
+  // block flush performed
+  static final private int BlockDone=1; 
+
+  // finish started, need only more output at next deflate
+  static final private int FinishStarted=2;
+
+  // finish done, accept no more input or output
+  static final private int FinishDone=3;
+
+  // preset dictionary flag in zlib header
+  static final private int PRESET_DICT=0x20;
+
+  static final private int Z_FILTERED=1;
+  static final private int Z_HUFFMAN_ONLY=2;
+  static final private int Z_DEFAULT_STRATEGY=0;
+
+  static final private int Z_NO_FLUSH=0;
+  static final private int Z_PARTIAL_FLUSH=1;
+  static final private int Z_SYNC_FLUSH=2;
+  static final private int Z_FULL_FLUSH=3;
+  static final private int Z_FINISH=4;
+
+  static final private int Z_OK=0;
+  static final private int Z_STREAM_END=1;
+  static final private int Z_NEED_DICT=2;
+  static final private int Z_ERRNO=-1;
+  static final private int Z_STREAM_ERROR=-2;
+  static final private int Z_DATA_ERROR=-3;
+  static final private int Z_MEM_ERROR=-4;
+  static final private int Z_BUF_ERROR=-5;
+  static final private int Z_VERSION_ERROR=-6;
+
+  static final private int INIT_STATE=42;
+  static final private int BUSY_STATE=113;
+  static final private int FINISH_STATE=666;
+
+  // The deflate compression method
+  static final private int Z_DEFLATED=8;
+
+  static final private int STORED_BLOCK=0;
+  static final private int STATIC_TREES=1;
+  static final private int DYN_TREES=2;
+
+  // The three kinds of block type
+  static final private int Z_BINARY=0;
+  static final private int Z_ASCII=1;
+  static final private int Z_UNKNOWN=2;
+
+  static final private int Buf_size=8*2;
+
+  // repeat previous bit length 3-6 times (2 bits of repeat count)
+  static final private int REP_3_6=16; 
+
+  // repeat a zero length 3-10 times  (3 bits of repeat count)
+  static final private int REPZ_3_10=17; 
+
+  // repeat a zero length 11-138 times  (7 bits of repeat count)
+  static final private int REPZ_11_138=18; 
+
+  static final private int MIN_MATCH=3;
+  static final private int MAX_MATCH=258;
+  static final private int MIN_LOOKAHEAD=(MAX_MATCH+MIN_MATCH+1);
+
+  static final private int MAX_BITS=15;
+  static final private int D_CODES=30;
+  static final private int BL_CODES=19;
+  static final private int LENGTH_CODES=29;
+  static final private int LITERALS=256;
+  static final private int L_CODES=(LITERALS+1+LENGTH_CODES);
+  static final private int HEAP_SIZE=(2*L_CODES+1);
+
+  static final private int END_BLOCK=256;
+
+  ZStream strm;        // pointer back to this zlib stream
+  int status;           // as the name implies
+  byte[] pending_buf;   // output still pending
+  int pending_buf_size; // size of pending_buf
+  int pending_out;      // next pending byte to output to the stream
+  int pending;          // nb of bytes in the pending buffer
+  int wrap = 1;
+  byte data_type;       // UNKNOWN, BINARY or ASCII
+  byte method;          // STORED (for zip only) or DEFLATED
+  int last_flush;       // value of flush param for previous deflate call
+
+  int w_size;           // LZ77 window size (32K by default)
+  int w_bits;           // log2(w_size)  (8..16)
+  int w_mask;           // w_size - 1
+
+  byte[] window;
+  // Sliding window. Input bytes are read into the second half of the window,
+  // and move to the first half later to keep a dictionary of at least wSize
+  // bytes. With this organization, matches are limited to a distance of
+  // wSize-MAX_MATCH bytes, but this ensures that IO is always
+  // performed with a length multiple of the block size. Also, it limits
+  // the window size to 64K, which is quite useful on MSDOS.
+  // To do: use the user input buffer as sliding window.
+
+  int window_size;
+  // Actual size of window: 2*wSize, except when the user input buffer
+  // is directly used as sliding window.
+
+  short[] prev;
+  // Link to older string with same hash index. To limit the size of this
+  // array to 64K, this link is maintained only for the last 32K strings.
+  // An index in this array is thus a window index modulo 32K.
+
+  short[] head; // Heads of the hash chains or NIL.
+
+  int ins_h;          // hash index of string to be inserted
+  int hash_size;      // number of elements in hash table
+  int hash_bits;      // log2(hash_size)
+  int hash_mask;      // hash_size-1
+
+  // Number of bits by which ins_h must be shifted at each input
+  // step. It must be such that after MIN_MATCH steps, the oldest
+  // byte no longer takes part in the hash key, that is:
+  // hash_shift * MIN_MATCH >= hash_bits
+  int hash_shift;
+
+  // Window position at the beginning of the current output block. Gets
+  // negative when the window is moved backwards.
+
+  int block_start;
+
+  int match_length;           // length of best match
+  int prev_match;             // previous match
+  int match_available;        // set if previous match exists
+  int strstart;               // start of string to insert
+  int match_start;            // start of matching string
+  int lookahead;              // number of valid bytes ahead in window
+
+  // Length of the best match at previous step. Matches not greater than this
+  // are discarded. This is used in the lazy match evaluation.
+  int prev_length;
+
+  // To speed up deflation, hash chains are never searched beyond this
+  // length.  A higher limit improves compression ratio but degrades the speed.
+  int max_chain_length;
+
+  // Attempt to find a better match only when the current match is strictly
+  // smaller than this value. This mechanism is used only for compression
+  // levels >= 4.
+  int max_lazy_match;
+
+  // Insert new strings in the hash table only if the match length is not
+  // greater than this length. This saves time but degrades compression.
+  // max_insert_length is used only for compression levels <= 3.
+
+  int level;    // compression level (1..9)
+  int strategy; // favor or force Huffman coding
+
+  // Use a faster search when the previous match is longer than this
+  int good_match;
+
+  // Stop searching when current match exceeds this
+  int nice_match;
+
+  short[] dyn_ltree;       // literal and length tree
+  short[] dyn_dtree;       // distance tree
+  short[] bl_tree;         // Huffman tree for bit lengths
+
+  Tree l_desc=new Tree();  // desc for literal tree
+  Tree d_desc=new Tree();  // desc for distance tree
+  Tree bl_desc=new Tree(); // desc for bit length tree
+
+  // number of codes at each bit length for an optimal tree
+  short[] bl_count=new short[MAX_BITS+1];
+  // working area to be used in Tree#gen_codes()
+  short[] next_code=new short[MAX_BITS+1];
+
+  // heap used to build the Huffman trees
+  int[] heap=new int[2*L_CODES+1];
+
+  int heap_len;               // number of elements in the heap
+  int heap_max;               // element of largest frequency
+  // The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
+  // The same heap array is used to build all trees.
+
+  // Depth of each subtree used as tie breaker for trees of equal frequency
+  byte[] depth=new byte[2*L_CODES+1];
+
+  byte[] l_buf;               // index for literals or lengths */
+
+  // Size of match buffer for literals/lengths.  There are 4 reasons for
+  // limiting lit_bufsize to 64K:
+  //   - frequencies can be kept in 16 bit counters
+  //   - if compression is not successful for the first block, all input
+  //     data is still in the window so we can still emit a stored block even
+  //     when input comes from standard input.  (This can also be done for
+  //     all blocks if lit_bufsize is not greater than 32K.)
+  //   - if compression is not successful for a file smaller than 64K, we can
+  //     even emit a stored file instead of a stored block (saving 5 bytes).
+  //     This is applicable only for zip (not gzip or zlib).
+  //   - creating new Huffman trees less frequently may not provide fast
+  //     adaptation to changes in the input data statistics. (Take for
+  //     example a binary file with poorly compressible code followed by
+  //     a highly compressible string table.) Smaller buffer sizes give
+  //     fast adaptation but have of course the overhead of transmitting
+  //     trees more frequently.
+  //   - I can't count above 4
+  int lit_bufsize;
+
+  int last_lit;      // running index in l_buf
+
+  // Buffer for distances. To simplify the code, d_buf and l_buf have
+  // the same number of elements. To use different lengths, an extra flag
+  // array would be necessary.
+
+  int d_buf;         // index of pendig_buf
+
+  int opt_len;        // bit length of current block with optimal trees
+  int static_len;     // bit length of current block with static trees
+  int matches;        // number of string matches in current block
+  int last_eob_len;   // bit length of EOB code for last block
+
+  // Output buffer. bits are inserted starting at the bottom (least
+  // significant bits).
+  short bi_buf;
+
+  // Number of valid bits in bi_buf.  All bits above the last valid bit
+  // are always zero.
+  int bi_valid;
+
+  GZIPHeader gheader = null;
+
+  Deflate(ZStream strm){
+    this.strm=strm;
+    dyn_ltree=new short[HEAP_SIZE*2];
+    dyn_dtree=new short[(2*D_CODES+1)*2]; // distance tree
+    bl_tree=new short[(2*BL_CODES+1)*2];  // Huffman tree for bit lengths
+  }
+
+  void lm_init() {
+    window_size=2*w_size;
+
+    head[hash_size-1]=0;
+    for(int i=0; i<hash_size-1; i++){
+      head[i]=0;
+    }
+
+    // Set the default configuration parameters:
+    max_lazy_match   = Deflate.config_table[level].max_lazy;
+    good_match       = Deflate.config_table[level].good_length;
+    nice_match       = Deflate.config_table[level].nice_length;
+    max_chain_length = Deflate.config_table[level].max_chain;
+
+    strstart = 0;
+    block_start = 0;
+    lookahead = 0;
+    match_length = prev_length = MIN_MATCH-1;
+    match_available = 0;
+    ins_h = 0;
+  }
+
+  // Initialize the tree data structures for a new zlib stream.
+  void tr_init(){
+
+    l_desc.dyn_tree = dyn_ltree;
+    l_desc.stat_desc = StaticTree.static_l_desc;
+
+    d_desc.dyn_tree = dyn_dtree;
+    d_desc.stat_desc = StaticTree.static_d_desc;
+
+    bl_desc.dyn_tree = bl_tree;
+    bl_desc.stat_desc = StaticTree.static_bl_desc;
+
+    bi_buf = 0;
+    bi_valid = 0;
+    last_eob_len = 8; // enough lookahead for inflate
+
+    // Initialize the first block of the first file:
+    init_block();
+  }
+
+  void init_block(){
+    // Initialize the trees.
+    for(int i = 0; i < L_CODES; i++) dyn_ltree[i*2] = 0;
+    for(int i= 0; i < D_CODES; i++) dyn_dtree[i*2] = 0;
+    for(int i= 0; i < BL_CODES; i++) bl_tree[i*2] = 0;
+
+    dyn_ltree[END_BLOCK*2] = 1;
+    opt_len = static_len = 0;
+    last_lit = matches = 0;
+  }
+
+  // Restore the heap property by moving down the tree starting at node k,
+  // exchanging a node with the smallest of its two sons if necessary, stopping
+  // when the heap property is re-established (each father smaller than its
+  // two sons).
+  void pqdownheap(short[] tree,  // the tree to restore
+		  int k          // node to move down
+		  ){
+    int v = heap[k];
+    int j = k << 1;  // left son of k
+    while (j <= heap_len) {
+      // Set j to the smallest of the two sons:
+      if (j < heap_len &&
+	  smaller(tree, heap[j+1], heap[j], depth)){
+	j++;
+      }
+      // Exit if v is smaller than both sons
+      if(smaller(tree, v, heap[j], depth)) break;
+
+      // Exchange v with the smallest son
+      heap[k]=heap[j];  k = j;
+      // And continue down the tree, setting j to the left son of k
+      j <<= 1;
+    }
+    heap[k] = v;
+  }
+
+  static boolean smaller(short[] tree, int n, int m, byte[] depth){
+    short tn2=tree[n*2];
+    short tm2=tree[m*2];
+    return (tn2<tm2 ||
+	    (tn2==tm2 && depth[n] <= depth[m]));
+  }
+
+  // Scan a literal or distance tree to determine the frequencies of the codes
+  // in the bit length tree.
+  void scan_tree (short[] tree,// the tree to be scanned
+		  int max_code // and its largest code of non zero frequency
+		  ){
+    int n;                     // iterates over all tree elements
+    int prevlen = -1;          // last emitted length
+    int curlen;                // length of current code
+    int nextlen = tree[0*2+1]; // length of next code
+    int count = 0;             // repeat count of the current code
+    int max_count = 7;         // max repeat count
+    int min_count = 4;         // min repeat count
+
+    if (nextlen == 0){ max_count = 138; min_count = 3; }
+    tree[(max_code+1)*2+1] = (short)0xffff; // guard
+
+    for(n = 0; n <= max_code; n++) {
+      curlen = nextlen; nextlen = tree[(n+1)*2+1];
+      if(++count < max_count && curlen == nextlen) {
+	continue;
+      }
+      else if(count < min_count) {
+	bl_tree[curlen*2] += count;
+      }
+      else if(curlen != 0) {
+	if(curlen != prevlen) bl_tree[curlen*2]++;
+	bl_tree[REP_3_6*2]++;
+      }
+      else if(count <= 10) {
+	bl_tree[REPZ_3_10*2]++;
+      }
+      else{
+	bl_tree[REPZ_11_138*2]++;
+      }
+      count = 0; prevlen = curlen;
+      if(nextlen == 0) {
+	max_count = 138; min_count = 3;
+      }
+      else if(curlen == nextlen) {
+	max_count = 6; min_count = 3;
+      }
+      else{
+	max_count = 7; min_count = 4;
+      }
+    }
+  }
+
+  // Construct the Huffman tree for the bit lengths and return the index in
+  // bl_order of the last bit length code to send.
+  int build_bl_tree(){
+    int max_blindex;  // index of last bit length code of non zero freq
+
+    // Determine the bit length frequencies for literal and distance trees
+    scan_tree(dyn_ltree, l_desc.max_code);
+    scan_tree(dyn_dtree, d_desc.max_code);
+
+    // Build the bit length tree:
+    bl_desc.build_tree(this);
+    // opt_len now includes the length of the tree representations, except
+    // the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
+
+    // Determine the number of bit length codes to send. The pkzip format
+    // requires that at least 4 bit length codes be sent. (appnote.txt says
+    // 3 but the actual value used is 4.)
+    for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
+      if (bl_tree[Tree.bl_order[max_blindex]*2+1] != 0) break;
+    }
+    // Update opt_len to include the bit length tree and counts
+    opt_len += 3*(max_blindex+1) + 5+5+4;
+
+    return max_blindex;
+  }
+
+
+  // Send the header for a block using dynamic Huffman trees: the counts, the
+  // lengths of the bit length codes, the literal tree and the distance tree.
+  // IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
+  void send_all_trees(int lcodes, int dcodes, int blcodes){
+    int rank;                    // index in bl_order
+
+    send_bits(lcodes-257, 5); // not +255 as stated in appnote.txt
+    send_bits(dcodes-1,   5);
+    send_bits(blcodes-4,  4); // not -3 as stated in appnote.txt
+    for (rank = 0; rank < blcodes; rank++) {
+      send_bits(bl_tree[Tree.bl_order[rank]*2+1], 3);
+    }
+    send_tree(dyn_ltree, lcodes-1); // literal tree
+    send_tree(dyn_dtree, dcodes-1); // distance tree
+  }
+
+  // Send a literal or distance tree in compressed form, using the codes in
+  // bl_tree.
+  void send_tree (short[] tree,// the tree to be sent
+		  int max_code // and its largest code of non zero frequency
+		  ){
+    int n;                     // iterates over all tree elements
+    int prevlen = -1;          // last emitted length
+    int curlen;                // length of current code
+    int nextlen = tree[0*2+1]; // length of next code
+    int count = 0;             // repeat count of the current code
+    int max_count = 7;         // max repeat count
+    int min_count = 4;         // min repeat count
+
+    if (nextlen == 0){ max_count = 138; min_count = 3; }
+
+    for (n = 0; n <= max_code; n++) {
+      curlen = nextlen; nextlen = tree[(n+1)*2+1];
+      if(++count < max_count && curlen == nextlen) {
+	continue;
+      }
+      else if(count < min_count) {
+	do { send_code(curlen, bl_tree); } while (--count != 0);
+      }
+      else if(curlen != 0){
+	if(curlen != prevlen){
+	  send_code(curlen, bl_tree); count--;
+	}
+	send_code(REP_3_6, bl_tree); 
+	send_bits(count-3, 2);
+      }
+      else if(count <= 10){
+	send_code(REPZ_3_10, bl_tree); 
+	send_bits(count-3, 3);
+      }
+      else{
+	send_code(REPZ_11_138, bl_tree);
+	send_bits(count-11, 7);
+      }
+      count = 0; prevlen = curlen;
+      if(nextlen == 0){
+	max_count = 138; min_count = 3;
+      }
+      else if(curlen == nextlen){
+	max_count = 6; min_count = 3;
+      }
+      else{
+	max_count = 7; min_count = 4;
+      }
+    }
+  }
+
+  // Output a byte on the stream.
+  // IN assertion: there is enough room in pending_buf.
+  final void put_byte(byte[] p, int start, int len){
+    System.arraycopy(p, start, pending_buf, pending, len);
+    pending+=len;
+  }
+
+  final void put_byte(byte c){
+    pending_buf[pending++]=c;
+  }
+  final void put_short(int w) {
+    put_byte((byte)(w/*&0xff*/));
+    put_byte((byte)(w>>>8));
+  }
+  final void putShortMSB(int b){
+    put_byte((byte)(b>>8));
+    put_byte((byte)(b/*&0xff*/));
+  }   
+
+  final void send_code(int c, short[] tree){
+    int c2=c*2;
+    send_bits((tree[c2]&0xffff), (tree[c2+1]&0xffff));
+  }
+
+  void send_bits(int value, int length){
+    int len = length;
+    if (bi_valid > (int)Buf_size - len) {
+      int val = value;
+//      bi_buf |= (val << bi_valid);
+      bi_buf |= ((val << bi_valid)&0xffff);
+      put_short(bi_buf);
+      bi_buf = (short)(val >>> (Buf_size - bi_valid));
+      bi_valid += len - Buf_size;
+    } else {
+//      bi_buf |= (value) << bi_valid;
+      bi_buf |= (((value) << bi_valid)&0xffff);
+      bi_valid += len;
+    }
+  }
+
+  // Send one empty static block to give enough lookahead for inflate.
+  // This takes 10 bits, of which 7 may remain in the bit buffer.
+  // The current inflate code requires 9 bits of lookahead. If the
+  // last two codes for the previous block (real code plus EOB) were coded
+  // on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
+  // the last real code. In this case we send two empty static blocks instead
+  // of one. (There are no problems if the previous block is stored or fixed.)
+  // To simplify the code, we assume the worst case of last real code encoded
+  // on one bit only.
+  void _tr_align(){
+    send_bits(STATIC_TREES<<1, 3);
+    send_code(END_BLOCK, StaticTree.static_ltree);
+
+    bi_flush();
+
+    // Of the 10 bits for the empty block, we have already sent
+    // (10 - bi_valid) bits. The lookahead for the last real code (before
+    // the EOB of the previous block) was thus at least one plus the length
+    // of the EOB plus what we have just sent of the empty static block.
+    if (1 + last_eob_len + 10 - bi_valid < 9) {
+      send_bits(STATIC_TREES<<1, 3);
+      send_code(END_BLOCK, StaticTree.static_ltree);
+      bi_flush();
+    }
+    last_eob_len = 7;
+  }
+
+
+  // Save the match info and tally the frequency counts. Return true if
+  // the current block must be flushed.
+  boolean _tr_tally (int dist, // distance of matched string
+		     int lc // match length-MIN_MATCH or unmatched char (if dist==0)
+		     ){
+
+    pending_buf[d_buf+last_lit*2] = (byte)(dist>>>8);
+    pending_buf[d_buf+last_lit*2+1] = (byte)dist;
+
+    l_buf[last_lit] = (byte)lc; last_lit++;
+
+    if (dist == 0) {
+      // lc is the unmatched char
+      dyn_ltree[lc*2]++;
+    } 
+    else {
+      matches++;
+      // Here, lc is the match length - MIN_MATCH
+      dist--;             // dist = match distance - 1
+      dyn_ltree[(Tree._length_code[lc]+LITERALS+1)*2]++;
+      dyn_dtree[Tree.d_code(dist)*2]++;
+    }
+
+    if ((last_lit & 0x1fff) == 0 && level > 2) {
+      // Compute an upper bound for the compressed length
+      int out_length = last_lit*8;
+      int in_length = strstart - block_start;
+      int dcode;
+      for (dcode = 0; dcode < D_CODES; dcode++) {
+	out_length += (int)dyn_dtree[dcode*2] *
+	  (5L+Tree.extra_dbits[dcode]);
+      }
+      out_length >>>= 3;
+      if ((matches < (last_lit/2)) && out_length < in_length/2) return true;
+    }
+
+    return (last_lit == lit_bufsize-1);
+    // We avoid equality with lit_bufsize because of wraparound at 64K
+    // on 16 bit machines and because stored blocks are restricted to
+    // 64K-1 bytes.
+  }
+
+  // Send the block data compressed using the given Huffman trees
+  void compress_block(short[] ltree, short[] dtree){
+    int  dist;      // distance of matched string
+    int lc;         // match length or unmatched char (if dist == 0)
+    int lx = 0;     // running index in l_buf
+    int code;       // the code to send
+    int extra;      // number of extra bits to send
+
+    if (last_lit != 0){
+      do{
+	dist=((pending_buf[d_buf+lx*2]<<8)&0xff00)|
+	  (pending_buf[d_buf+lx*2+1]&0xff);
+	lc=(l_buf[lx])&0xff; lx++;
+
+	if(dist == 0){
+	  send_code(lc, ltree); // send a literal byte
+	} 
+	else{
+	  // Here, lc is the match length - MIN_MATCH
+	  code = Tree._length_code[lc];
+
+	  send_code(code+LITERALS+1, ltree); // send the length code
+	  extra = Tree.extra_lbits[code];
+	  if(extra != 0){
+	    lc -= Tree.base_length[code];
+	    send_bits(lc, extra);       // send the extra length bits
+	  }
+	  dist--; // dist is now the match distance - 1
+	  code = Tree.d_code(dist);
+
+	  send_code(code, dtree);       // send the distance code
+	  extra = Tree.extra_dbits[code];
+	  if (extra != 0) {
+	    dist -= Tree.base_dist[code];
+	    send_bits(dist, extra);   // send the extra distance bits
+	  }
+	} // literal or match pair ?
+
+	// Check that the overlay between pending_buf and d_buf+l_buf is ok:
+      }
+      while (lx < last_lit);
+    }
+
+    send_code(END_BLOCK, ltree);
+    last_eob_len = ltree[END_BLOCK*2+1];
+  }
+
+  // Set the data type to ASCII or BINARY, using a crude approximation:
+  // binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
+  // IN assertion: the fields freq of dyn_ltree are set and the total of all
+  // frequencies does not exceed 64K (to fit in an int on 16 bit machines).
+  void set_data_type(){
+    int n = 0;
+    int  ascii_freq = 0;
+    int  bin_freq = 0;
+    while(n<7){ bin_freq += dyn_ltree[n*2]; n++;}
+    while(n<128){ ascii_freq += dyn_ltree[n*2]; n++;}
+    while(n<LITERALS){ bin_freq += dyn_ltree[n*2]; n++;}
+    data_type=(byte)(bin_freq > (ascii_freq >>> 2) ? Z_BINARY : Z_ASCII);
+  }
+
+  // Flush the bit buffer, keeping at most 7 bits in it.
+  void bi_flush(){
+    if (bi_valid == 16) {
+      put_short(bi_buf);
+      bi_buf=0;
+      bi_valid=0;
+    }
+    else if (bi_valid >= 8) {
+      put_byte((byte)bi_buf);
+      bi_buf>>>=8;
+      bi_valid-=8;
+    }
+  }
+
+  // Flush the bit buffer and align the output on a byte boundary
+  void bi_windup(){
+    if (bi_valid > 8) {
+      put_short(bi_buf);
+    } else if (bi_valid > 0) {
+      put_byte((byte)bi_buf);
+    }
+    bi_buf = 0;
+    bi_valid = 0;
+  }
+
+  // Copy a stored block, storing first the length and its
+  // one's complement if requested.
+  void copy_block(int buf,         // the input data
+		  int len,         // its length
+		  boolean header   // true if block header must be written
+		  ){
+    int index=0;
+    bi_windup();      // align on byte boundary
+    last_eob_len = 8; // enough lookahead for inflate
+
+    if (header) {
+      put_short((short)len);   
+      put_short((short)~len);
+    }
+
+    //  while(len--!=0) {
+    //    put_byte(window[buf+index]);
+    //    index++;
+    //  }
+    put_byte(window, buf, len);
+  }
+
+  void flush_block_only(boolean eof){
+    _tr_flush_block(block_start>=0 ? block_start : -1,
+		    strstart-block_start,
+		    eof);
+    block_start=strstart;
+    strm.flush_pending();
+  }
+
+  // Copy without compression as much as possible from the input stream, return
+  // the current block state.
+  // This function does not insert new strings in the dictionary since
+  // uncompressible data is probably not useful. This function is used
+  // only for the level=0 compression option.
+  // NOTE: this function should be optimized to avoid extra copying from
+  // window to pending_buf.
+  int deflate_stored(int flush){
+    // Stored blocks are limited to 0xffff bytes, pending_buf is limited
+    // to pending_buf_size, and each stored block has a 5 byte header:
+
+    int max_block_size = 0xffff;
+    int max_start;
+
+    if(max_block_size > pending_buf_size - 5) {
+      max_block_size = pending_buf_size - 5;
+    }
+
+    // Copy as much as possible from input to output:
+    while(true){
+      // Fill the window as much as possible:
+      if(lookahead<=1){
+	fill_window();
+	if(lookahead==0 && flush==Z_NO_FLUSH) return NeedMore;
+	if(lookahead==0) break; // flush the current block
+      }
+
+      strstart+=lookahead;
+      lookahead=0;
+
+      // Emit a stored block if pending_buf will be full:
+      max_start=block_start+max_block_size;
+      if(strstart==0|| strstart>=max_start) {
+	// strstart == 0 is possible when wraparound on 16-bit machine
+	lookahead = (int)(strstart-max_start);
+	strstart = (int)max_start;
+      
+	flush_block_only(false);
+	if(strm.avail_out==0) return NeedMore;
+
+      }
+
+      // Flush if we may have to slide, otherwise block_start may become
+      // negative and the data will be gone:
+      if(strstart-block_start >= w_size-MIN_LOOKAHEAD) {
+	flush_block_only(false);
+	if(strm.avail_out==0) return NeedMore;
+      }
+    }
+
+    flush_block_only(flush == Z_FINISH);
+    if(strm.avail_out==0)
+      return (flush == Z_FINISH) ? FinishStarted : NeedMore;
+
+    return flush == Z_FINISH ? FinishDone : BlockDone;
+  }
+
+  // Send a stored block
+  void _tr_stored_block(int buf,        // input block
+			int stored_len, // length of input block
+			boolean eof     // true if this is the last block for a file
+			){
+    send_bits((STORED_BLOCK<<1)+(eof?1:0), 3);  // send block type
+    copy_block(buf, stored_len, true);          // with header
+  }
+
+  // Determine the best encoding for the current block: dynamic trees, static
+  // trees or store, and output the encoded block to the zip file.
+  void _tr_flush_block(int buf,        // input block, or NULL if too old
+		       int stored_len, // length of input block
+		       boolean eof     // true if this is the last block for a file
+		       ) {
+    int opt_lenb, static_lenb;// opt_len and static_len in bytes
+    int max_blindex = 0;      // index of last bit length code of non zero freq
+
+    // Build the Huffman trees unless a stored block is forced
+    if(level > 0) {
+      // Check if the file is ascii or binary
+      if(data_type == Z_UNKNOWN) set_data_type();
+
+      // Construct the literal and distance trees
+      l_desc.build_tree(this);
+
+      d_desc.build_tree(this);
+
+      // At this point, opt_len and static_len are the total bit lengths of
+      // the compressed block data, excluding the tree representations.
+
+      // Build the bit length tree for the above two trees, and get the index
+      // in bl_order of the last bit length code to send.
+      max_blindex=build_bl_tree();
+
+      // Determine the best encoding. Compute first the block length in bytes
+      opt_lenb=(opt_len+3+7)>>>3;
+      static_lenb=(static_len+3+7)>>>3;
+
+      if(static_lenb<=opt_lenb) opt_lenb=static_lenb;
+    }
+    else {
+      opt_lenb=static_lenb=stored_len+5; // force a stored block
+    }
+
+    if(stored_len+4<=opt_lenb && buf != -1){
+      // 4: two words for the lengths
+      // The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
+      // Otherwise we can't have processed more than WSIZE input bytes since
+      // the last block flush, because compression would have been
+      // successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
+      // transform a block into a stored block.
+      _tr_stored_block(buf, stored_len, eof);
+    }
+    else if(static_lenb == opt_lenb){
+      send_bits((STATIC_TREES<<1)+(eof?1:0), 3);
+      compress_block(StaticTree.static_ltree, StaticTree.static_dtree);
+    }
+    else{
+      send_bits((DYN_TREES<<1)+(eof?1:0), 3);
+      send_all_trees(l_desc.max_code+1, d_desc.max_code+1, max_blindex+1);
+      compress_block(dyn_ltree, dyn_dtree);
+    }
+
+    // The above check is made mod 2^32, for files larger than 512 MB
+    // and uLong implemented on 32 bits.
+
+    init_block();
+
+    if(eof){
+      bi_windup();
+    }
+  }
+
+  // Fill the window when the lookahead becomes insufficient.
+  // Updates strstart and lookahead.
+  //
+  // IN assertion: lookahead < MIN_LOOKAHEAD
+  // OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
+  //    At least one byte has been read, or avail_in == 0; reads are
+  //    performed for at least two bytes (required for the zip translate_eol
+  //    option -- not supported here).
+  void fill_window(){
+    int n, m;
+    int p;
+    int more;    // Amount of free space at the end of the window.
+
+    do{
+      more = (window_size-lookahead-strstart);
+
+      // Deal with !@#$% 64K limit:
+      if(more==0 && strstart==0 && lookahead==0){
+	more = w_size;
+      } 
+      else if(more==-1) {
+	// Very unlikely, but possible on 16 bit machine if strstart == 0
+	// and lookahead == 1 (input done one byte at time)
+	more--;
+
+	// 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.
+      }
+      else if(strstart >= w_size+ w_size-MIN_LOOKAHEAD) {
+	System.arraycopy(window, w_size, window, 0, w_size);
+	match_start-=w_size;
+	strstart-=w_size; // we now have strstart >= MAX_DIST
+	block_start-=w_size;
+
+	// Slide the hash table (could be avoided with 32 bit values
+	// at the expense of memory usage). We slide even when level == 0
+	// to keep the hash table consistent if we switch back to level > 0
+	// later. (Using level 0 permanently is not an optimal usage of
+	// zlib, so we don't care about this pathological case.)
+
+	n = hash_size;
+	p=n;
+	do {
+	  m = (head[--p]&0xffff);
+	  head[p]=(m>=w_size ? (short)(m-w_size) : 0);
+	}
+	while (--n != 0);
+
+	n = w_size;
+	p = n;
+	do {
+	  m = (prev[--p]&0xffff);
+	  prev[p] = (m >= w_size ? (short)(m-w_size) : 0);
+	  // If n is not on any hash chain, prev[n] is garbage but
+	  // its value will never be used.
+	}
+	while (--n!=0);
+	more += w_size;
+      }
+
+      if (strm.avail_in == 0) return;
+
+      // If there was no sliding:
+      //    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
+      //    more == window_size - lookahead - strstart
+      // => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
+      // => more >= window_size - 2*WSIZE + 2
+      // In the BIG_MEM or MMAP case (not yet supported),
+      //   window_size == input_size + MIN_LOOKAHEAD  &&
+      //   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
+      // Otherwise, window_size == 2*WSIZE so more >= 2.
+      // If there was sliding, more >= WSIZE. So in all cases, more >= 2.
+
+      n = strm.read_buf(window, strstart + lookahead, more);
+      lookahead += n;
+
+      // Initialize the hash value now that we have some input:
+      if(lookahead >= MIN_MATCH) {
+	ins_h = window[strstart]&0xff;
+	ins_h=(((ins_h)<<hash_shift)^(window[strstart+1]&0xff))&hash_mask;
+      }
+      // If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
+      // but this is not important since only literal bytes will be emitted.
+    }
+    while (lookahead < MIN_LOOKAHEAD && strm.avail_in != 0);
+  }
+
+  // Compress as much as possible from the input stream, return the current
+  // block state.
+  // This function does not perform lazy evaluation of matches and inserts
+  // new strings in the dictionary only for unmatched strings or for short
+  // matches. It is used only for the fast compression options.
+  int deflate_fast(int flush){
+//    short hash_head = 0; // head of the hash chain
+    int hash_head = 0; // head of the hash chain
+    boolean bflush;      // set if current block must be flushed
+
+    while(true){
+      // Make sure that we always have enough lookahead, except
+      // at the end of the input file. We need MAX_MATCH bytes
+      // for the next match, plus MIN_MATCH bytes to insert the
+      // string following the next match.
+      if(lookahead < MIN_LOOKAHEAD){
+	fill_window();
+	if(lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH){
+	  return NeedMore;
+	}
+	if(lookahead == 0) break; // flush the current block
+      }
+
+      // Insert the string window[strstart .. strstart+2] in the
+      // dictionary, and set hash_head to the head of the hash chain:
+      if(lookahead >= MIN_MATCH){
+	ins_h=(((ins_h)<<hash_shift)^(window[(strstart)+(MIN_MATCH-1)]&0xff))&hash_mask;
+
+//	prev[strstart&w_mask]=hash_head=head[ins_h];
+        hash_head=(head[ins_h]&0xffff);
+	prev[strstart&w_mask]=head[ins_h];
+	head[ins_h]=(short)strstart;
+      }
+
+      // Find the longest match, discarding those <= prev_length.
+      // At this point we have always match_length < MIN_MATCH
+
+      if(hash_head!=0L && 
+	 ((strstart-hash_head)&0xffff) <= w_size-MIN_LOOKAHEAD
+	 ){
+	// To simplify the code, we prevent matches with the string
+	// of window index 0 (in particular we have to avoid a match
+	// of the string with itself at the start of the input file).
+	if(strategy != Z_HUFFMAN_ONLY){
+	  match_length=longest_match (hash_head);
+	}
+	// longest_match() sets match_start
+      }
+      if(match_length>=MIN_MATCH){
+	//        check_match(strstart, match_start, match_length);
+
+	bflush=_tr_tally(strstart-match_start, match_length-MIN_MATCH);
+
+	lookahead -= match_length;
+
+	// Insert new strings in the hash table only if the match length
+	// is not too large. This saves time but degrades compression.
+	if(match_length <= max_lazy_match &&
+	   lookahead >= MIN_MATCH) {
+	  match_length--; // string at strstart already in hash table
+	  do{
+	    strstart++;
+
+	    ins_h=((ins_h<<hash_shift)^(window[(strstart)+(MIN_MATCH-1)]&0xff))&hash_mask;
+//	    prev[strstart&w_mask]=hash_head=head[ins_h];
+	    hash_head=(head[ins_h]&0xffff);
+	    prev[strstart&w_mask]=head[ins_h];
+	    head[ins_h]=(short)strstart;
+
+	    // strstart never exceeds WSIZE-MAX_MATCH, so there are
+	    // always MIN_MATCH bytes ahead.
+	  }
+	  while (--match_length != 0);
+	  strstart++; 
+	}
+	else{
+	  strstart += match_length;
+	  match_length = 0;
+	  ins_h = window[strstart]&0xff;
+
+	  ins_h=(((ins_h)<<hash_shift)^(window[strstart+1]&0xff))&hash_mask;
+	  // If lookahead < MIN_MATCH, ins_h is garbage, but it does not
+	  // matter since it will be recomputed at next deflate call.
+	}
+      }
+      else {
+	// No match, output a literal byte
+
+	bflush=_tr_tally(0, window[strstart]&0xff);
+	lookahead--;
+	strstart++; 
+      }
+      if (bflush){
+
+	flush_block_only(false);
+	if(strm.avail_out==0) return NeedMore;
+      }
+    }
+
+    flush_block_only(flush == Z_FINISH);
+    if(strm.avail_out==0){
+      if(flush == Z_FINISH) return FinishStarted;
+      else return NeedMore;
+    }
+    return flush==Z_FINISH ? FinishDone : BlockDone;
+  }
+
+  // Same as above, but achieves better compression. We use a lazy
+  // evaluation for matches: a match is finally adopted only if there is
+  // no better match at the next window position.
+  int deflate_slow(int flush){
+//    short hash_head = 0;    // head of hash chain
+    int hash_head = 0;    // head of hash chain
+    boolean bflush;         // set if current block must be flushed
+
+    // Process the input block.
+    while(true){
+      // Make sure that we always have enough lookahead, except
+      // at the end of the input file. We need MAX_MATCH bytes
+      // for the next match, plus MIN_MATCH bytes to insert the
+      // string following the next match.
+
+      if (lookahead < MIN_LOOKAHEAD) {
+	fill_window();
+	if(lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
+	  return NeedMore;
+	}
+	if(lookahead == 0) break; // flush the current block
+      }
+
+      // Insert the string window[strstart .. strstart+2] in the
+      // dictionary, and set hash_head to the head of the hash chain:
+
+      if(lookahead >= MIN_MATCH) {
+	ins_h=(((ins_h)<<hash_shift)^(window[(strstart)+(MIN_MATCH-1)]&0xff)) & hash_mask;
+//	prev[strstart&w_mask]=hash_head=head[ins_h];
+	hash_head=(head[ins_h]&0xffff);
+	prev[strstart&w_mask]=head[ins_h];
+	head[ins_h]=(short)strstart;
+      }
+
+      // Find the longest match, discarding those <= prev_length.
+      prev_length = match_length; prev_match = match_start;
+      match_length = MIN_MATCH-1;
+
+      if (hash_head != 0 && prev_length < max_lazy_match &&
+	  ((strstart-hash_head)&0xffff) <= w_size-MIN_LOOKAHEAD
+	  ){
+	// To simplify the code, we prevent matches with the string
+	// of window index 0 (in particular we have to avoid a match
+	// of the string with itself at the start of the input file).
+
+	if(strategy != Z_HUFFMAN_ONLY) {
+	  match_length = longest_match(hash_head);
+	}
+	// longest_match() sets match_start
+
+	if (match_length <= 5 && (strategy == Z_FILTERED ||
+				  (match_length == MIN_MATCH &&
+				   strstart - match_start > 4096))) {
+
+	  // If prev_match is also MIN_MATCH, match_start is garbage
+	  // but we will ignore the current match anyway.
+	  match_length = MIN_MATCH-1;
+	}
+      }
+
+      // If there was a match at the previous step and the current
+      // match is not better, output the previous match:
+      if(prev_length >= MIN_MATCH && match_length <= prev_length) {
+	int max_insert = strstart + lookahead - MIN_MATCH;
+	// Do not insert strings in hash table beyond this.
+
+	//          check_match(strstart-1, prev_match, prev_length);
+
+	bflush=_tr_tally(strstart-1-prev_match, prev_length - MIN_MATCH);
+
+	// Insert in hash table all strings up to the end of the match.
+	// strstart-1 and strstart are already inserted. If there is not
+	// enough lookahead, the last two strings are not inserted in
+	// the hash table.
+	lookahead -= prev_length-1;
+	prev_length -= 2;
+	do{
+	  if(++strstart <= max_insert) {
+	    ins_h=(((ins_h)<<hash_shift)^(window[(strstart)+(MIN_MATCH-1)]&0xff))&hash_mask;
+	    //prev[strstart&w_mask]=hash_head=head[ins_h];
+	    hash_head=(head[ins_h]&0xffff);
+	    prev[strstart&w_mask]=head[ins_h];
+	    head[ins_h]=(short)strstart;
+	  }
+	}
+	while(--prev_length != 0);
+	match_available = 0;
+	match_length = MIN_MATCH-1;
+	strstart++;
+
+	if (bflush){
+	  flush_block_only(false);
+	  if(strm.avail_out==0) return NeedMore;
+	}
+      } else if (match_available!=0) {
+
+	// If there was no match at the previous position, output a
+	// single literal. If there was a match but the current match
+	// is longer, truncate the previous match to a single literal.
+
+	bflush=_tr_tally(0, window[strstart-1]&0xff);
+
+	if (bflush) {
+	  flush_block_only(false);
+	}
+	strstart++;
+	lookahead--;
+	if(strm.avail_out == 0) return NeedMore;
+      } else {
+	// There is no previous match to compare with, wait for
+	// the next step to decide.
+
+	match_available = 1;
+	strstart++;
+	lookahead--;
+      }
+    }
+
+    if(match_available!=0) {
+      bflush=_tr_tally(0, window[strstart-1]&0xff);
+      match_available = 0;
+    }
+    flush_block_only(flush == Z_FINISH);
+
+    if(strm.avail_out==0){
+      if(flush == Z_FINISH) return FinishStarted;
+      else return NeedMore;
+    }
+
+    return flush == Z_FINISH ? FinishDone : BlockDone;
+  }
+
+  int longest_match(int cur_match){
+    int chain_length = max_chain_length; // max hash chain length
+    int scan = strstart;                 // current string
+    int match;                           // matched string
+    int len;                             // length of current match
+    int best_len = prev_length;          // best match length so far
+    int limit = strstart>(w_size-MIN_LOOKAHEAD) ?
+      strstart-(w_size-MIN_LOOKAHEAD) : 0;
+    int nice_match=this.nice_match;
+
+    // Stop when cur_match becomes <= limit. To simplify the code,
+    // we prevent matches with the string of window index 0.
+
+    int wmask = w_mask;
+
+    int strend = strstart + MAX_MATCH;
+    byte scan_end1 = window[scan+best_len-1];
+    byte scan_end = window[scan+best_len];
+
+    // The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
+    // It is easy to get rid of this optimization if necessary.
+
+    // Do not waste too much time if we already have a good match:
+    if (prev_length >= good_match) {
+      chain_length >>= 2;
+    }
+
+    // Do not look for matches beyond the end of the input. This is necessary
+    // to make deflate deterministic.
+    if (nice_match > lookahead) nice_match = lookahead;
+
+    do {
+      match = cur_match;
+
+      // Skip to next match if the match length cannot increase
+      // or if the match length is less than 2:
+      if (window[match+best_len]   != scan_end  ||
+	  window[match+best_len-1] != scan_end1 ||
+	  window[match]       != window[scan]     ||
+	  window[++match]     != window[scan+1])      continue;
+
+      // The check at best_len-1 can be removed because it will be made
+      // again later. (This heuristic is not always a win.)
+      // It is not necessary to compare scan[2] and match[2] since they
+      // are always equal when the other bytes match, given that
+      // the hash keys are equal and that HASH_BITS >= 8.
+      scan += 2; match++;
+
+      // We check for insufficient lookahead only every 8th comparison;
+      // the 256th check will be made at strstart+258.
+      do {
+      } 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);
+
+      len = MAX_MATCH - (int)(strend - scan);
+      scan = strend - MAX_MATCH;
+
+      if(len>best_len) {
+	match_start = cur_match;
+	best_len = len;
+	if (len >= nice_match) break;
+	scan_end1  = window[scan+best_len-1];
+	scan_end   = window[scan+best_len];
+      }
+
+    } while ((cur_match = (prev[cur_match & wmask]&0xffff)) > limit
+	     && --chain_length != 0);
+
+    if (best_len <= lookahead) return best_len;
+    return lookahead;
+  }
+
+  int deflateInit(int level, int bits, int memlevel){
+    return deflateInit(level, Z_DEFLATED, bits, memlevel,
+			Z_DEFAULT_STRATEGY);
+  }
+    
+  int deflateInit(int level, int bits){
+    return deflateInit(level, Z_DEFLATED, bits, DEF_MEM_LEVEL,
+			Z_DEFAULT_STRATEGY);
+  }
+  int deflateInit(int level){
+    return deflateInit(level, MAX_WBITS);
+  }
+  private int deflateInit(int level, int method,  int windowBits,
+			  int memLevel, int strategy){
+    int wrap = 1;
+    //    byte[] my_version=ZLIB_VERSION;
+
+    //
+    //  if (version == null || version[0] != my_version[0]
+    //  || stream_size != sizeof(z_stream)) {
+    //  return Z_VERSION_ERROR;
+    //  }
+
+    strm.msg = null;
+
+    if (level == Z_DEFAULT_COMPRESSION) level = 6;
+
+    if (windowBits < 0) { // undocumented feature: suppress zlib header
+      wrap = 0;
+      windowBits = -windowBits;
+    }
+    else if(windowBits > 15){
+      wrap = 2;
+      windowBits -= 16;
+      strm.adler=new CRC32();
+    }
+
+    if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || 
+	method != Z_DEFLATED ||
+	windowBits < 9 || windowBits > 15 || level < 0 || level > 9 ||
+        strategy < 0 || strategy > Z_HUFFMAN_ONLY) {
+      return Z_STREAM_ERROR;
+    }
+
+    strm.dstate = (Deflate)this;
+
+    this.wrap = wrap;
+    w_bits = windowBits;
+    w_size = 1 << w_bits;
+    w_mask = w_size - 1;
+
+    hash_bits = memLevel + 7;
+    hash_size = 1 << hash_bits;
+    hash_mask = hash_size - 1;
+    hash_shift = ((hash_bits+MIN_MATCH-1)/MIN_MATCH);
+
+    window = new byte[w_size*2];
+    prev = new short[w_size];
+    head = new short[hash_size];
+
+    lit_bufsize = 1 << (memLevel + 6); // 16K elements by default
+
+    // We overlay pending_buf and d_buf+l_buf. This works since the average
+    // output size for (length,distance) codes is <= 24 bits.
+    pending_buf = new byte[lit_bufsize*3];
+    pending_buf_size = lit_bufsize*3;
+
+    d_buf = lit_bufsize;
+    l_buf = new byte[lit_bufsize];
+
+    this.level = level;
+
+    this.strategy = strategy;
+    this.method = (byte)method;
+
+    return deflateReset();
+  }
+
+  int deflateReset(){
+    strm.total_in = strm.total_out = 0;
+    strm.msg = null; //
+    strm.data_type = Z_UNKNOWN;
+
+    pending = 0;
+    pending_out = 0;
+
+    if(wrap < 0){
+      wrap = -wrap;
+    }
+    status = (wrap==0) ? BUSY_STATE : INIT_STATE;
+    strm.adler.reset();
+
+    last_flush = Z_NO_FLUSH;
+
+    tr_init();
+    lm_init();
+    return Z_OK;
+  }
+
+  int deflateEnd(){
+    if(status!=INIT_STATE && status!=BUSY_STATE && status!=FINISH_STATE){
+      return Z_STREAM_ERROR;
+    }
+    // Deallocate in reverse order of allocations:
+    pending_buf=null;
+    l_buf=null;
+    head=null;
+    prev=null;
+    window=null;
+    // free
+    // dstate=null;
+    return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
+  }
+
+  int deflateParams(int _level, int _strategy){
+    int err=Z_OK;
+
+    if(_level == Z_DEFAULT_COMPRESSION){
+      _level = 6;
+    }
+    if(_level < 0 || _level > 9 || 
+       _strategy < 0 || _strategy > Z_HUFFMAN_ONLY) {
+      return Z_STREAM_ERROR;
+    }
+
+    if(config_table[level].func!=config_table[_level].func &&
+       strm.total_in != 0) {
+      // Flush the last buffer:
+      err = strm.deflate(Z_PARTIAL_FLUSH);
+    }
+
+    if(level != _level) {
+      level = _level;
+      max_lazy_match   = config_table[level].max_lazy;
+      good_match       = config_table[level].good_length;
+      nice_match       = config_table[level].nice_length;
+      max_chain_length = config_table[level].max_chain;
+    }
+    strategy = _strategy;
+    return err;
+  }
+
+  int deflateSetDictionary (byte[] dictionary, int dictLength){
+    int length = dictLength;
+    int index=0;
+
+    if(dictionary == null || status != INIT_STATE)
+      return Z_STREAM_ERROR;
+
+    strm.adler.update(dictionary, 0, dictLength);
+
+    if(length < MIN_MATCH) return Z_OK;
+    if(length > w_size-MIN_LOOKAHEAD){
+      length = w_size-MIN_LOOKAHEAD;
+      index=dictLength-length; // use the tail of the dictionary
+    }
+    System.arraycopy(dictionary, index, window, 0, length);
+    strstart = length;
+    block_start = length;
+
+    // Insert all strings in the hash table (except for the last two bytes).
+    // s->lookahead stays null, so s->ins_h will be recomputed at the next
+    // call of fill_window.
+
+    ins_h = window[0]&0xff;
+    ins_h=(((ins_h)<<hash_shift)^(window[1]&0xff))&hash_mask;
+
+    for(int n=0; n<=length-MIN_MATCH; n++){
+      ins_h=(((ins_h)<<hash_shift)^(window[(n)+(MIN_MATCH-1)]&0xff))&hash_mask;
+      prev[n&w_mask]=head[ins_h];
+      head[ins_h]=(short)n;
+    }
+    return Z_OK;
+  }
+
+  int deflate(int flush){
+    int old_flush;
+
+    if(flush>Z_FINISH || flush<0){
+      return Z_STREAM_ERROR;
+    }
+
+    if(strm.next_out == null ||
+       (strm.next_in == null && strm.avail_in != 0) ||
+       (status == FINISH_STATE && flush != Z_FINISH)) {
+      strm.msg=z_errmsg[Z_NEED_DICT-(Z_STREAM_ERROR)];
+      return Z_STREAM_ERROR;
+    }
+    if(strm.avail_out == 0){
+      strm.msg=z_errmsg[Z_NEED_DICT-(Z_BUF_ERROR)];
+      return Z_BUF_ERROR;
+    }
+
+    old_flush = last_flush;
+    last_flush = flush;
+
+    // Write the zlib header
+    if(status == INIT_STATE) {
+      if(wrap == 2){
+        getGZIPHeader().put(this);
+        status=BUSY_STATE;
+        strm.adler.reset();
+      }
+      else{
+      int header = (Z_DEFLATED+((w_bits-8)<<4))<<8;
+      int level_flags=((level-1)&0xff)>>1;
+
+      if(level_flags>3) level_flags=3;
+      header |= (level_flags<<6);
+      if(strstart!=0) header |= PRESET_DICT;
+      header+=31-(header % 31);
+
+      status=BUSY_STATE;
+      putShortMSB(header);
+
+
+      // Save the adler32 of the preset dictionary:
+      if(strstart!=0){
+        long adler=strm.adler.getValue();
+        putShortMSB((int)(adler>>>16));
+        putShortMSB((int)(adler&0xffff));
+      }
+      strm.adler.reset();
+      }
+    }
+
+    // Flush as much pending output as possible
+    if(pending != 0) {
+      strm.flush_pending();
+      if(strm.avail_out == 0) {
+	// Since avail_out is 0, deflate will be called again with
+	// more output space, but possibly with both pending and
+	// avail_in equal to zero. There won't be anything to do,
+	// but this is not an error situation so make sure we
+	// return OK instead of BUF_ERROR at next call of deflate:
+	last_flush = -1;
+	return Z_OK;
+      }
+
+      // Make sure there is something to do and avoid duplicate consecutive
+      // flushes. For repeated and useless calls with Z_FINISH, we keep
+      // returning Z_STREAM_END instead of Z_BUFF_ERROR.
+    }
+    else if(strm.avail_in==0 && flush <= old_flush &&
+	    flush != Z_FINISH) {
+      strm.msg=z_errmsg[Z_NEED_DICT-(Z_BUF_ERROR)];
+      return Z_BUF_ERROR;
+    }
+
+    // User must not provide more input after the first FINISH:
+    if(status == FINISH_STATE && strm.avail_in != 0) {
+      strm.msg=z_errmsg[Z_NEED_DICT-(Z_BUF_ERROR)];
+      return Z_BUF_ERROR;
+    }
+
+    // Start a new block or continue the current one.
+    if(strm.avail_in!=0 || lookahead!=0 ||
+       (flush != Z_NO_FLUSH && status != FINISH_STATE)) {
+      int bstate=-1;
+      switch(config_table[level].func){
+      case STORED: 
+	bstate = deflate_stored(flush);
+	break;
+      case FAST: 
+	bstate = deflate_fast(flush);
+	break;
+      case SLOW: 
+	bstate = deflate_slow(flush);
+	break;
+      default:
+      }
+
+      if (bstate==FinishStarted || bstate==FinishDone) {
+	status = FINISH_STATE;
+      }
+      if (bstate==NeedMore || bstate==FinishStarted) {
+	if(strm.avail_out == 0) {
+	  last_flush = -1; // avoid BUF_ERROR next call, see above
+	}
+	return Z_OK;
+	// If flush != Z_NO_FLUSH && avail_out == 0, the next call
+	// of deflate should use the same flush parameter to make sure
+	// that the flush is complete. So we don't have to output an
+	// empty block here, this will be done at next call. This also
+	// ensures that for a very small output buffer, we emit at most
+	// one empty block.
+      }
+
+      if (bstate==BlockDone) {
+	if(flush == Z_PARTIAL_FLUSH) {
+	  _tr_align();
+	} 
+	else { // FULL_FLUSH or SYNC_FLUSH
+	  _tr_stored_block(0, 0, false);
+	  // For a full flush, this empty block will be recognized
+	  // as a special marker by inflate_sync().
+	  if(flush == Z_FULL_FLUSH) {
+	    //state.head[s.hash_size-1]=0;
+	    for(int i=0; i<hash_size/*-1*/; i++)  // forget history
+	      head[i]=0;
+	  }
+	}
+	strm.flush_pending();
+	if(strm.avail_out == 0) {
+	  last_flush = -1; // avoid BUF_ERROR at next call, see above
+	  return Z_OK;
+	}
+      }
+    }
+
+    if(flush!=Z_FINISH) return Z_OK;
+    if(wrap<=0) return Z_STREAM_END;
+
+    if(wrap==2){
+      long adler=strm.adler.getValue();
+      put_byte((byte)(adler&0xff));
+      put_byte((byte)((adler>>8)&0xff));
+      put_byte((byte)((adler>>16)&0xff));
+      put_byte((byte)((adler>>24)&0xff));
+      put_byte((byte)(strm.total_in&0xff));
+      put_byte((byte)((strm.total_in>>8)&0xff));
+      put_byte((byte)((strm.total_in>>16)&0xff));
+      put_byte((byte)((strm.total_in>>24)&0xff));
+
+      getGZIPHeader().setCRC(adler);
+    } 
+    else{
+      // Write the zlib trailer (adler32)
+      long adler=strm.adler.getValue();
+      putShortMSB((int)(adler>>>16));
+      putShortMSB((int)(adler&0xffff));
+    }
+
+    strm.flush_pending();
+
+    // If avail_out is zero, the application will call deflate again
+    // to flush the rest.
+
+    if(wrap > 0) wrap = -wrap; // write the trailer only once!
+    return pending != 0 ? Z_OK : Z_STREAM_END;
+  }
+
+  static int deflateCopy(ZStream dest, ZStream src){
+
+    if(src.dstate == null){
+      return Z_STREAM_ERROR;
+    }
+
+    if(src.next_in!=null){
+      dest.next_in = new byte[src.next_in.length];
+      System.arraycopy(src.next_in, 0, dest.next_in, 0, src.next_in.length);
+    }
+    dest.next_in_index = src.next_in_index;
+    dest.avail_in = src.avail_in;
+    dest.total_in = src.total_in;
+
+    if(src.next_out!=null){
+      dest.next_out = new byte[src.next_out.length];
+      System.arraycopy(src.next_out, 0, dest.next_out ,0 , src.next_out.length);
+    }
+
+    dest.next_out_index = src.next_out_index;
+    dest.avail_out = src.avail_out;
+    dest.total_out = src.total_out;
+
+    dest.msg = src.msg;
+    dest.data_type = src.data_type;
+    dest.adler = src.adler.copy();
+
+    try{
+      dest.dstate = (Deflate)src.dstate.clone();
+      dest.dstate.strm = dest;
+    }
+    catch(CloneNotSupportedException e){
+      //
+    }
+    return Z_OK;
+  }
+
+  public Object clone() throws CloneNotSupportedException {
+    Deflate dest = (Deflate)super.clone();
+
+    dest.pending_buf = dup(dest.pending_buf);
+    dest.d_buf = dest.d_buf;
+    dest.l_buf = dup(dest.l_buf);
+    dest.window = dup(dest.window);
+
+    dest.prev = dup(dest.prev);
+    dest.head = dup(dest.head);
+    dest.dyn_ltree = dup(dest.dyn_ltree);
+    dest.dyn_dtree = dup(dest.dyn_dtree);
+    dest.bl_tree = dup(dest.bl_tree);
+
+    dest.bl_count = dup(dest.bl_count);
+    dest.next_code = dup(dest.next_code);
+    dest.heap = dup(dest.heap);
+    dest.depth = dup(dest.depth);
+
+    dest.l_desc.dyn_tree = dest.dyn_ltree;
+    dest.d_desc.dyn_tree = dest.dyn_dtree;
+    dest.bl_desc.dyn_tree = dest.bl_tree;
+
+    /*
+    dest.l_desc.stat_desc = StaticTree.static_l_desc;
+    dest.d_desc.stat_desc = StaticTree.static_d_desc;
+    dest.bl_desc.stat_desc = StaticTree.static_bl_desc;
+    */
+
+    if(dest.gheader!=null){
+      dest.gheader = (GZIPHeader)dest.gheader.clone();
+    }
+
+    return dest;
+  }
+
+  private byte[] dup(byte[] buf){
+    byte[] foo = new byte[buf.length];
+    System.arraycopy(buf, 0, foo, 0, foo.length);
+    return foo;
+  }
+  private short[] dup(short[] buf){
+    short[] foo = new short[buf.length];
+    System.arraycopy(buf, 0, foo, 0, foo.length);
+    return foo;
+  }
+  private int[] dup(int[] buf){
+    int[] foo = new int[buf.length];
+    System.arraycopy(buf, 0, foo, 0, foo.length);
+    return foo;
+  }
+
+  synchronized GZIPHeader getGZIPHeader(){
+    if(gheader==null){
+      gheader = new GZIPHeader();
+    }
+    return gheader;
+  }
+}