lzw vs gzip

Benchmark created by Eloff on


Preparation HTML

<script src="https://dl.dropboxusercontent.com/u/23110948/ufg-min.js"></script>

Setup

foo = {}
    
    /*
     * $Id: rawdeflate.js,v 0.5 2013/04/09 14:25:38 dankogai Exp dankogai $
     *
     * GNU General Public License, version 2 (GPL-2.0)
     *   http://opensource.org/licenses/GPL-2.0
     * Original:
     *  http://www.onicos.com/staff/iz/amuse/javascript/expert/deflate.txt
     */
    
    (function(ctx){
    
    /* Copyright (C) 1999 Masanao Izumo <iz@onicos.co.jp>
     * Version: 1.0.1
     * LastModified: Dec 25 1999
     */
    
    /* Interface:
     * data = zip_deflate(src);
     */
    
    /* constant parameters */
    var zip_WSIZE = 32768;              // Sliding Window size
    var zip_STORED_BLOCK = 0;
    var zip_STATIC_TREES = 1;
    var zip_DYN_TREES    = 2;
    
    /* for deflate */
    var zip_DEFAULT_LEVEL = 6;
    var zip_FULL_SEARCH = true;
    var zip_INBUFSIZ = 32768;   // Input buffer size
    var zip_INBUF_EXTRA = 64;   // Extra buffer
    var zip_OUTBUFSIZ = 1024 * 8;
    var zip_window_size = 2 * zip_WSIZE;
    var zip_MIN_MATCH = 3;
    var zip_MAX_MATCH = 258;
    var zip_BITS = 16;
    // for SMALL_MEM
    var zip_LIT_BUFSIZE = 0x2000;
    var zip_HASH_BITS = 13;
    // for MEDIUM_MEM
    // var zip_LIT_BUFSIZE = 0x4000;
    // var zip_HASH_BITS = 14;
    // for BIG_MEM
    // var zip_LIT_BUFSIZE = 0x8000;
    // var zip_HASH_BITS = 15;
    if(zip_LIT_BUFSIZE > zip_INBUFSIZ)
        alert("error: zip_INBUFSIZ is too small");
    if((zip_WSIZE<<1) > (1<<zip_BITS))
        alert("error: zip_WSIZE is too large");
    if(zip_HASH_BITS > zip_BITS-1)
        alert("error: zip_HASH_BITS is too large");
    if(zip_HASH_BITS < 8 || zip_MAX_MATCH != 258)
        alert("error: Code too clever");
    var zip_DIST_BUFSIZE = zip_LIT_BUFSIZE;
    var zip_HASH_SIZE = 1 << zip_HASH_BITS;
    var zip_HASH_MASK = zip_HASH_SIZE - 1;
    var zip_WMASK = zip_WSIZE - 1;
    var zip_NIL = 0; // Tail of hash chains
    var zip_TOO_FAR = 4096;
    var zip_MIN_LOOKAHEAD = zip_MAX_MATCH + zip_MIN_MATCH + 1;
    var zip_MAX_DIST = zip_WSIZE - zip_MIN_LOOKAHEAD;
    var zip_SMALLEST = 1;
    var zip_MAX_BITS = 15;
    var zip_MAX_BL_BITS = 7;
    var zip_LENGTH_CODES = 29;
    var zip_LITERALS =256;
    var zip_END_BLOCK = 256;
    var zip_L_CODES = zip_LITERALS + 1 + zip_LENGTH_CODES;
    var zip_D_CODES = 30;
    var zip_BL_CODES = 19;
    var zip_REP_3_6 = 16;
    var zip_REPZ_3_10 = 17;
    var zip_REPZ_11_138 = 18;
    var zip_HEAP_SIZE = 2 * zip_L_CODES + 1;
    var zip_H_SHIFT = parseInt((zip_HASH_BITS + zip_MIN_MATCH - 1) /
                           zip_MIN_MATCH);
    
    /* variables */
    var zip_free_queue;
    var zip_qhead, zip_qtail;
    var zip_initflag;
    var zip_outbuf = null;
    var zip_outcnt, zip_outoff;
    var zip_complete;
    var zip_window;
    var zip_d_buf;
    var zip_l_buf;
    var zip_prev;
    var zip_bi_buf;
    var zip_bi_valid;
    var zip_block_start;
    var zip_ins_h;
    var zip_hash_head;
    var zip_prev_match;
    var zip_match_available;
    var zip_match_length;
    var zip_prev_length;
    var zip_strstart;
    var zip_match_start;
    var zip_eofile;
    var zip_lookahead;
    var zip_max_chain_length;
    var zip_max_lazy_match;
    var zip_compr_level;
    var zip_good_match;
    var zip_nice_match;
    var zip_dyn_ltree;
    var zip_dyn_dtree;
    var zip_static_ltree;
    var zip_static_dtree;
    var zip_bl_tree;
    var zip_l_desc;
    var zip_d_desc;
    var zip_bl_desc;
    var zip_bl_count;
    var zip_heap;
    var zip_heap_len;
    var zip_heap_max;
    var zip_depth;
    var zip_length_code;
    var zip_dist_code;
    var zip_base_length;
    var zip_base_dist;
    var zip_flag_buf;
    var zip_last_lit;
    var zip_last_dist;
    var zip_last_flags;
    var zip_flags;
    var zip_flag_bit;
    var zip_opt_len;
    var zip_static_len;
    var zip_deflate_data;
    var zip_deflate_pos;
    
    /* objects (deflate) */
    
    var zip_DeflateCT = function() {
        this.fc = 0; // frequency count or bit string
        this.dl = 0; // father node in Huffman tree or length of bit string
    }
    
    var zip_DeflateTreeDesc = function() {
        this.dyn_tree = null;   // the dynamic tree
        this.static_tree = null;        // corresponding static tree or NULL
        this.extra_bits = null; // extra bits for each code or NULL
        this.extra_base = 0;    // base index for extra_bits
        this.elems = 0;         // max number of elements in the tree
        this.max_length = 0;    // max bit length for the codes
        this.max_code = 0;              // largest code with non zero frequency
    }
    
    /* Values for max_lazy_match, good_match and max_chain_length, depending on
     * the desired pack level (0..9). The values given below have been tuned to
     * exclude worst case performance for pathological files. Better values may be
     * found for specific files.
     */
    var zip_DeflateConfiguration = function(a, b, c, d) {
        this.good_length = a; // reduce lazy search above this match length
        this.max_lazy = b;    // do not perform lazy search above this match length
        this.nice_length = c; // quit search above this match length
        this.max_chain = d;
    }
    
    var zip_DeflateBuffer = function() {
        this.next = null;
        this.len = 0;
        this.ptr = new Array(zip_OUTBUFSIZ);
        this.off = 0;
    }
    
    /* constant tables */
    var zip_extra_lbits = new Array(
        0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0);
    var zip_extra_dbits = new Array(
        0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13);
    var zip_extra_blbits = new Array(
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7);
    var zip_bl_order = new Array(
        16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15);
    var zip_configuration_table = new Array(
        new zip_DeflateConfiguration(0,    0,   0,    0),
        new zip_DeflateConfiguration(4,    4,   8,    4),
        new zip_DeflateConfiguration(4,    5,  16,    8),
        new zip_DeflateConfiguration(4,    6,  32,   32),
        new zip_DeflateConfiguration(4,    4,  16,   16),
        new zip_DeflateConfiguration(8,   16,  32,   32),
        new zip_DeflateConfiguration(8,   16, 128,  128),
        new zip_DeflateConfiguration(8,   32, 128,  256),
        new zip_DeflateConfiguration(32, 128, 258, 1024),
        new zip_DeflateConfiguration(32, 258, 258, 4096));
    
    
    /* routines (deflate) */
    
    var zip_deflate_start = function(level) {
        var i;
    
        if(!level)
        level = zip_DEFAULT_LEVEL;
        else if(level < 1)
        level = 1;
        else if(level > 9)
        level = 9;
    
        zip_compr_level = level;
        zip_initflag = false;
        zip_eofile = false;
        if(zip_outbuf != null)
        return;
    
        zip_free_queue = zip_qhead = zip_qtail = null;
        zip_outbuf = new Array(zip_OUTBUFSIZ);
        zip_window = new Array(zip_window_size);
        zip_d_buf = new Array(zip_DIST_BUFSIZE);
        zip_l_buf = new Array(zip_INBUFSIZ + zip_INBUF_EXTRA);
        zip_prev = new Array(1 << zip_BITS);
        zip_dyn_ltree = new Array(zip_HEAP_SIZE);
        for(i = 0; i < zip_HEAP_SIZE; i++)
        zip_dyn_ltree[i] = new zip_DeflateCT();
        zip_dyn_dtree = new Array(2*zip_D_CODES+1);
        for(i = 0; i < 2*zip_D_CODES+1; i++)
        zip_dyn_dtree[i] = new zip_DeflateCT();
        zip_static_ltree = new Array(zip_L_CODES+2);
        for(i = 0; i < zip_L_CODES+2; i++)
        zip_static_ltree[i] = new zip_DeflateCT();
        zip_static_dtree = new Array(zip_D_CODES);
        for(i = 0; i < zip_D_CODES; i++)
        zip_static_dtree[i] = new zip_DeflateCT();
        zip_bl_tree = new Array(2*zip_BL_CODES+1);
        for(i = 0; i < 2*zip_BL_CODES+1; i++)
        zip_bl_tree[i] = new zip_DeflateCT();
        zip_l_desc = new zip_DeflateTreeDesc();
        zip_d_desc = new zip_DeflateTreeDesc();
        zip_bl_desc = new zip_DeflateTreeDesc();
        zip_bl_count = new Array(zip_MAX_BITS+1);
        zip_heap = new Array(2*zip_L_CODES+1);
        zip_depth = new Array(2*zip_L_CODES+1);
        zip_length_code = new Array(zip_MAX_MATCH-zip_MIN_MATCH+1);
        zip_dist_code = new Array(512);
        zip_base_length = new Array(zip_LENGTH_CODES);
        zip_base_dist = new Array(zip_D_CODES);
        zip_flag_buf = new Array(parseInt(zip_LIT_BUFSIZE / 8));
    }
    
    var zip_deflate_end = function() {
        zip_free_queue = zip_qhead = zip_qtail = null;
        zip_outbuf = null;
        zip_window = null;
        zip_d_buf = null;
        zip_l_buf = null;
        zip_prev = null;
        zip_dyn_ltree = null;
        zip_dyn_dtree = null;
        zip_static_ltree = null;
        zip_static_dtree = null;
        zip_bl_tree = null;
        zip_l_desc = null;
        zip_d_desc = null;
        zip_bl_desc = null;
        zip_bl_count = null;
        zip_heap = null;
        zip_depth = null;
        zip_length_code = null;
        zip_dist_code = null;
        zip_base_length = null;
        zip_base_dist = null;
        zip_flag_buf = null;
    }
    
    var zip_reuse_queue = function(p) {
        p.next = zip_free_queue;
        zip_free_queue = p;
    }
    
    var zip_new_queue = function() {
        var p;
    
        if(zip_free_queue != null)
        {
        p = zip_free_queue;
        zip_free_queue = zip_free_queue.next;
        }
        else
        p = new zip_DeflateBuffer();
        p.next = null;
        p.len = p.off = 0;
    
        return p;
    }
    
    var zip_head1 = function(i) {
        return zip_prev[zip_WSIZE + i];
    }
    
    var zip_head2 = function(i, val) {
        return zip_prev[zip_WSIZE + i] = val;
    }
    
    /* put_byte is used for the compressed output, put_ubyte for the
     * uncompressed output. However unlzw() uses window for its
     * suffix table instead of its output buffer, so it does not use put_ubyte
     * (to be cleaned up).
     */
    var zip_put_byte = function(c) {
        zip_outbuf[zip_outoff + zip_outcnt++] = c;
        if(zip_outoff + zip_outcnt == zip_OUTBUFSIZ)
        zip_qoutbuf();
    }
    
    /* Output a 16 bit value, lsb first */
    var zip_put_short = function(w) {
        w &= 0xffff;
        if(zip_outoff + zip_outcnt < zip_OUTBUFSIZ - 2) {
        zip_outbuf[zip_outoff + zip_outcnt++] = (w & 0xff);
        zip_outbuf[zip_outoff + zip_outcnt++] = (w >>> 8);
        } else {
        zip_put_byte(w & 0xff);
        zip_put_byte(w >>> 8);
        }
    }
    
    /* ==========================================================================
     * Insert string s in the dictionary and set match_head to the previous head
     * of the hash chain (the most recent string with same hash key). Return
     * the previous length of the hash chain.
     * IN  assertion: all calls to to INSERT_STRING are made with consecutive
     *    input characters and the first MIN_MATCH bytes of s are valid
     *    (except for the last MIN_MATCH-1 bytes of the input file).
     */
    var zip_INSERT_STRING = function() {
        zip_ins_h = ((zip_ins_h << zip_H_SHIFT)
                 ^ (zip_window[zip_strstart + zip_MIN_MATCH - 1] & 0xff))
        & zip_HASH_MASK;
        zip_hash_head = zip_head1(zip_ins_h);
        zip_prev[zip_strstart & zip_WMASK] = zip_hash_head;
        zip_head2(zip_ins_h, zip_strstart);
    }
    
    /* Send a code of the given tree. c and tree must not have side effects */
    var zip_SEND_CODE = function(c, tree) {
        zip_send_bits(tree[c].fc, tree[c].dl);
    }
    
    /* Mapping from a distance to a distance code. dist is the distance - 1 and
     * must not have side effects. dist_code[256] and dist_code[257] are never
     * used.
     */
    var zip_D_CODE = function(dist) {
        return (dist < 256 ? zip_dist_code[dist]
            : zip_dist_code[256 + (dist>>7)]) & 0xff;
    }
    
    /* ==========================================================================
     * Compares to subtrees, using the tree depth as tie breaker when
     * the subtrees have equal frequency. This minimizes the worst case length.
     */
    var zip_SMALLER = function(tree, n, m) {
        return tree[n].fc < tree[m].fc ||
          (tree[n].fc == tree[m].fc && zip_depth[n] <= zip_depth[m]);
    }
    
    /* ==========================================================================
     * read string data
     */
    var zip_read_buff = function(buff, offset, n) {
        var i;
        for(i = 0; i < n && zip_deflate_pos < zip_deflate_data.length; i++)
        buff[offset + i] =
            zip_deflate_data.charCodeAt(zip_deflate_pos++) & 0xff;
        return i;
    }
    
    /* ==========================================================================
     * Initialize the "longest match" routines for a new file
     */
    var zip_lm_init = function() {
        var j;
    
        /* Initialize the hash table. */
        for(j = 0; j < zip_HASH_SIZE; j++)
    //  zip_head2(j, zip_NIL);
        zip_prev[zip_WSIZE + j] = 0;
        /* prev will be initialized on the fly */
    
        /* Set the default configuration parameters:
         */
        zip_max_lazy_match = zip_configuration_table[zip_compr_level].max_lazy;
        zip_good_match     = zip_configuration_table[zip_compr_level].good_length;
        if(!zip_FULL_SEARCH)
        zip_nice_match = zip_configuration_table[zip_compr_level].nice_length;
        zip_max_chain_length = zip_configuration_table[zip_compr_level].max_chain;
    
        zip_strstart = 0;
        zip_block_start = 0;
    
        zip_lookahead = zip_read_buff(zip_window, 0, 2 * zip_WSIZE);
        if(zip_lookahead <= 0) {
        zip_eofile = true;
        zip_lookahead = 0;
        return;
        }
        zip_eofile = false;
        /* Make sure that we always have enough lookahead. This is important
         * if input comes from a device such as a tty.
         */
        while(zip_lookahead < zip_MIN_LOOKAHEAD && !zip_eofile)
        zip_fill_window();
    
        /* If lookahead < MIN_MATCH, ins_h is garbage, but this is
         * not important since only literal bytes will be emitted.
         */
        zip_ins_h = 0;
        for(j = 0; j < zip_MIN_MATCH - 1; j++) {
    //      UPDATE_HASH(ins_h, window[j]);
        zip_ins_h = ((zip_ins_h << zip_H_SHIFT) ^ (zip_window[j] & 0xff)) & zip_HASH_MASK;
        }
    }
    
    /* ==========================================================================
     * Set match_start to the longest match starting at the given string and
     * return its length. Matches shorter or equal to prev_length are discarded,
     * in which case the result is equal to prev_length and match_start is
     * garbage.
     * IN assertions: cur_match is the head of the hash chain for the current
     *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
     */
    var zip_longest_match = function(cur_match) {
        var chain_length = zip_max_chain_length; // max hash chain length
        var scanp = zip_strstart; // current string
        var matchp;             // matched string
        var len;                // length of current match
        var best_len = zip_prev_length; // best match length so far
    
        /* Stop when cur_match becomes <= limit. To simplify the code,
         * we prevent matches with the string of window index 0.
         */
        var limit = (zip_strstart > zip_MAX_DIST ? zip_strstart - zip_MAX_DIST : zip_NIL);
    
        var strendp = zip_strstart + zip_MAX_MATCH;
        var scan_end1 = zip_window[scanp + best_len - 1];
        var scan_end  = zip_window[scanp + best_len];
    
        /* Do not waste too much time if we already have a good match: */
        if(zip_prev_length >= zip_good_match)
        chain_length >>= 2;
    
    //  Assert(encoder->strstart <= window_size-MIN_LOOKAHEAD, "insufficient lookahead");
    
        do {
    //    Assert(cur_match < encoder->strstart, "no future");
        matchp = cur_match;
    
        /* Skip to next match if the match length cannot increase
            * or if the match length is less than 2:
        */
        if(zip_window[matchp + best_len]        != scan_end  ||
           zip_window[matchp + best_len - 1]    != scan_end1 ||
           zip_window[matchp]                   != zip_window[scanp] ||
           zip_window[++matchp]                 != zip_window[scanp + 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.
             */
        scanp += 2;
        matchp++;
    
        /* We check for insufficient lookahead only every 8th comparison;
             * the 256th check will be made at strstart+258.
             */
        do {
        } while(zip_window[++scanp] == zip_window[++matchp] &&
                zip_window[++scanp] == zip_window[++matchp] &&
                zip_window[++scanp] == zip_window[++matchp] &&
                zip_window[++scanp] == zip_window[++matchp] &&
                zip_window[++scanp] == zip_window[++matchp] &&
                zip_window[++scanp] == zip_window[++matchp] &&
                zip_window[++scanp] == zip_window[++matchp] &&
                zip_window[++scanp] == zip_window[++matchp] &&
                scanp < strendp);
    
          len = zip_MAX_MATCH - (strendp - scanp);
          scanp = strendp - zip_MAX_MATCH;
    
          if(len > best_len) {
          zip_match_start = cur_match;
          best_len = len;
          if(zip_FULL_SEARCH) {
              if(len >= zip_MAX_MATCH) break;
          } else {
              if(len >= zip_nice_match) break;
          }
    
          scan_end1  = zip_window[scanp + best_len-1];
          scan_end   = zip_window[scanp + best_len];
          }
        } while((cur_match = zip_prev[cur_match & zip_WMASK]) > limit
            && --chain_length != 0);
    
        return best_len;
    }
    
    /* ==========================================================================
     * Fill the window when the lookahead becomes insufficient.
     * Updates strstart and lookahead, and sets eofile if end of input file.
     * IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0
     * OUT assertions: at least one byte has been read, or eofile is set;
     *    file reads are performed for at least two bytes (required for the
     *    translate_eol option).
     */
    var zip_fill_window = function() {
        var n, m;
    
        // Amount of free space at the end of the window.
        var more = zip_window_size - zip_lookahead - zip_strstart;
    
        /* 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(more == -1) {
        /* Very unlikely, but possible on 16 bit machine if strstart == 0
             * and lookahead == 1 (input done one byte at time)
             */
        more--;
        } else if(zip_strstart >= zip_WSIZE + zip_MAX_DIST) {
        /* By the IN assertion, the window is not empty so we can't confuse
             * more == 0 with more == 64K on a 16 bit machine.
             */
    //  Assert(window_size == (ulg)2*WSIZE, "no sliding with BIG_MEM");
    
    //  System.arraycopy(window, WSIZE, window, 0, WSIZE);
        for(n = 0; n < zip_WSIZE; n++)
            zip_window[n] = zip_window[n + zip_WSIZE];
          
        zip_match_start -= zip_WSIZE;
        zip_strstart    -= zip_WSIZE; /* we now have strstart >= MAX_DIST: */
        zip_block_start -= zip_WSIZE;
    
        for(n = 0; n < zip_HASH_SIZE; n++) {
            m = zip_head1(n);
            zip_head2(n, m >= zip_WSIZE ? m - zip_WSIZE : zip_NIL);
        }
        for(n = 0; n < zip_WSIZE; n++) {
            /* If n is not on any hash chain, prev[n] is garbage but
             * its value will never be used.
             */
            m = zip_prev[n];
            zip_prev[n] = (m >= zip_WSIZE ? m - zip_WSIZE : zip_NIL);
        }
        more += zip_WSIZE;
        }
        // At this point, more >= 2
        if(!zip_eofile) {
        n = zip_read_buff(zip_window, zip_strstart + zip_lookahead, more);
        if(n <= 0)
            zip_eofile = true;
        else
            zip_lookahead += n;
        }
    }
    
    /* ==========================================================================
     * Processes a new input file and return its compressed length. This
     * function does not perform lazy evaluationof 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.
     */
    var zip_deflate_fast = function() {
        while(zip_lookahead != 0 && zip_qhead == null) {
        var flush; // set if current block must be flushed
    
        /* Insert the string window[strstart .. strstart+2] in the
         * dictionary, and set hash_head to the head of the hash chain:
         */
        zip_INSERT_STRING();
    
        /* Find the longest match, discarding those <= prev_length.
         * At this point we have always match_length < MIN_MATCH
         */
        if(zip_hash_head != zip_NIL &&
           zip_strstart - zip_hash_head <= zip_MAX_DIST) {
            /* 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).
             */
            zip_match_length = zip_longest_match(zip_hash_head);
            /* longest_match() sets match_start */
            if(zip_match_length > zip_lookahead)
                zip_match_length = zip_lookahead;
        }
        if(zip_match_length >= zip_MIN_MATCH) {
    //      check_match(strstart, match_start, match_length);
    
            flush = zip_ct_tally(zip_strstart - zip_match_start,
                                 zip_match_length - zip_MIN_MATCH);
            zip_lookahead -= zip_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(zip_match_length <= zip_max_lazy_match) {
                zip_match_length--; // string at strstart already in hash table
                do {
                    zip_strstart++;
                    zip_INSERT_STRING();
                    /* strstart never exceeds WSIZE-MAX_MATCH, so there are
                     * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH
                     * these bytes are garbage, but it does not matter since
                     * the next lookahead bytes will be emitted as literals.
                     */
                } while(--zip_match_length != 0);
                zip_strstart++;
            } else {
                zip_strstart += zip_match_length;
                zip_match_length = 0;
                zip_ins_h = zip_window[zip_strstart] & 0xff;
    //          UPDATE_HASH(ins_h, window[strstart + 1]);
                zip_ins_h = ((zip_ins_h<<zip_H_SHIFT) ^ (zip_window[zip_strstart + 1] & 0xff)) & zip_HASH_MASK;
    
    //#if MIN_MATCH != 3
    //          Call UPDATE_HASH() MIN_MATCH-3 more times
    //#endif
    
            }
        } else {
            /* No match, output a literal byte */
            flush = zip_ct_tally(0, zip_window[zip_strstart] & 0xff);
            zip_lookahead--;
            zip_strstart++;
        }
        if(flush) {
            zip_flush_block(0);
            zip_block_start = zip_strstart;
        }
    
        /* 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.
         */
        while(zip_lookahead < zip_MIN_LOOKAHEAD && !zip_eofile)
            zip_fill_window();
        }
    }
    
    var zip_deflate_better = function() {
        /* Process the input block. */
        while(zip_lookahead != 0 && zip_qhead == null) {
        /* Insert the string window[strstart .. strstart+2] in the
         * dictionary, and set hash_head to the head of the hash chain:
         */
        zip_INSERT_STRING();
    
        /* Find the longest match, discarding those <= prev_length.
         */
        zip_prev_length = zip_match_length;
        zip_prev_match = zip_match_start;
        zip_match_length = zip_MIN_MATCH - 1;
    
        if(zip_hash_head != zip_NIL &&
           zip_prev_length < zip_max_lazy_match &&
           zip_strstart - zip_hash_head <= zip_MAX_DIST) {
            /* 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).
             */
            zip_match_length = zip_longest_match(zip_hash_head);
            /* longest_match() sets match_start */
            if(zip_match_length > zip_lookahead)
                zip_match_length = zip_lookahead;
    
            /* Ignore a length 3 match if it is too distant: */
            if(zip_match_length == zip_MIN_MATCH &&
               zip_strstart - zip_match_start > zip_TOO_FAR) {
                /* If prev_match is also MIN_MATCH, match_start is garbage
                 * but we will ignore the current match anyway.
                 */
                zip_match_length--;
            }
        }
        /* If there was a match at the previous step and the current
         * match is not better, output the previous match:
         */
        if(zip_prev_length >= zip_MIN_MATCH &&
           zip_match_length <= zip_prev_length) {
            var flush; // set if current block must be flushed
    
    //      check_match(strstart - 1, prev_match, prev_length);
            flush = zip_ct_tally(zip_strstart - 1 - zip_prev_match,
                                 zip_prev_length - zip_MIN_MATCH);
    
            /* Insert in hash table all strings up to the end of the match.
             * strstart-1 and strstart are already inserted.
             */
            zip_lookahead -= zip_prev_length - 1;
            zip_prev_length -= 2;
            do {
                zip_strstart++;
                zip_INSERT_STRING();
                /* strstart never exceeds WSIZE-MAX_MATCH, so there are
                 * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH
                 * these bytes are garbage, but it does not matter since the
                 * next lookahead bytes will always be emitted as literals.
                 */
            } while(--zip_prev_length != 0);
            zip_match_available = 0;
            zip_match_length = zip_MIN_MATCH - 1;
            zip_strstart++;
            if(flush) {
                zip_flush_block(0);
                zip_block_start = zip_strstart;
            }
        } else if(zip_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.
             */
            if(zip_ct_tally(0, zip_window[zip_strstart - 1] & 0xff)) {
                zip_flush_block(0);
                zip_block_start = zip_strstart;
            }
            zip_strstart++;
            zip_lookahead--;
        } else {
            /* There is no previous match to compare with, wait for
             * the next step to decide.
             */
            zip_match_available = 1;
            zip_strstart++;
            zip_lookahead--;
        }
    
        /* 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.
         */
        while(zip_lookahead < zip_MIN_LOOKAHEAD && !zip_eofile)
            zip_fill_window();
        }
    }
    
    var zip_init_deflate = function() {
        if(zip_eofile)
        return;
        zip_bi_buf = 0;
        zip_bi_valid = 0;
        zip_ct_init();
        zip_lm_init();
    
        zip_qhead = null;
        zip_outcnt = 0;
        zip_outoff = 0;
        zip_match_available = 0;
    
        if(zip_compr_level <= 3)
        {
        zip_prev_length = zip_MIN_MATCH - 1;
        zip_match_length = 0;
        }
        else
        {
        zip_match_length = zip_MIN_MATCH - 1;
        zip_match_available = 0;
            zip_match_available = 0;
        }
    
        zip_complete = false;
    }
    
    /* ==========================================================================
     * 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.
     */
    var zip_deflate_internal = function(buff, off, buff_size) {
        var n;
    
        if(!zip_initflag)
        {
        zip_init_deflate();
        zip_initflag = true;
        if(zip_lookahead == 0) { // empty
            zip_complete = true;
            return 0;
        }
        }
    
        if((n = zip_qcopy(buff, off, buff_size)) == buff_size)
        return buff_size;
    
        if(zip_complete)
        return n;
    
        if(zip_compr_level <= 3) // optimized for speed
        zip_deflate_fast();
        else
        zip_deflate_better();
        if(zip_lookahead == 0) {
        if(zip_match_available != 0)
            zip_ct_tally(0, zip_window[zip_strstart - 1] & 0xff);
        zip_flush_block(1);
        zip_complete = true;
        }
        return n + zip_qcopy(buff, n + off, buff_size - n);
    }
    
    var zip_qcopy = function(buff, off, buff_size) {
        var n, i, j;
    
        n = 0;
        while(zip_qhead != null && n < buff_size)
        {
        i = buff_size - n;
        if(i > zip_qhead.len)
            i = zip_qhead.len;
    //      System.arraycopy(qhead.ptr, qhead.off, buff, off + n, i);
        for(j = 0; j < i; j++)
            buff[off + n + j] = zip_qhead.ptr[zip_qhead.off + j];
        
        zip_qhead.off += i;
        zip_qhead.len -= i;
        n += i;
        if(zip_qhead.len == 0) {
            var p;
            p = zip_qhead;
            zip_qhead = zip_qhead.next;
            zip_reuse_queue(p);
        }
        }
    
        if(n == buff_size)
        return n;
    
        if(zip_outoff < zip_outcnt) {
        i = buff_size - n;
        if(i > zip_outcnt - zip_outoff)
            i = zip_outcnt - zip_outoff;
        // System.arraycopy(outbuf, outoff, buff, off + n, i);
        for(j = 0; j < i; j++)
            buff[off + n + j] = zip_outbuf[zip_outoff + j];
        zip_outoff += i;
        n += i;
        if(zip_outcnt == zip_outoff)
            zip_outcnt = zip_outoff = 0;
        }
        return n;
    }
    
    /* ==========================================================================
     * Allocate the match buffer, initialize the various tables and save the
     * location of the internal file attribute (ascii/binary) and method
     * (DEFLATE/STORE).
     */
    var zip_ct_init = function() {
        var n;  // iterates over tree elements
        var bits;       // bit counter
        var length;     // length value
        var code;       // code value
        var dist;       // distance index
    
        if(zip_static_dtree[0].dl != 0) return; // ct_init already called
    
        zip_l_desc.dyn_tree             = zip_dyn_ltree;
        zip_l_desc.static_tree  = zip_static_ltree;
        zip_l_desc.extra_bits   = zip_extra_lbits;
        zip_l_desc.extra_base   = zip_LITERALS + 1;
        zip_l_desc.elems                = zip_L_CODES;
        zip_l_desc.max_length   = zip_MAX_BITS;
        zip_l_desc.max_code             = 0;
    
        zip_d_desc.dyn_tree             = zip_dyn_dtree;
        zip_d_desc.static_tree  = zip_static_dtree;
        zip_d_desc.extra_bits   = zip_extra_dbits;
        zip_d_desc.extra_base   = 0;
        zip_d_desc.elems                = zip_D_CODES;
        zip_d_desc.max_length   = zip_MAX_BITS;
        zip_d_desc.max_code             = 0;
    
        zip_bl_desc.dyn_tree    = zip_bl_tree;
        zip_bl_desc.static_tree = null;
        zip_bl_desc.extra_bits  = zip_extra_blbits;
        zip_bl_desc.extra_base  = 0;
        zip_bl_desc.elems               = zip_BL_CODES;
        zip_bl_desc.max_length  = zip_MAX_BL_BITS;
        zip_bl_desc.max_code    = 0;
    
        // Initialize the mapping length (0..255) -> length code (0..28)
        length = 0;
        for(code = 0; code < zip_LENGTH_CODES-1; code++) {
        zip_base_length[code] = length;
        for(n = 0; n < (1<<zip_extra_lbits[code]); n++)
            zip_length_code[length++] = code;
        }
        // Assert (length == 256, "ct_init: length != 256");
    
        /* Note that the length 255 (match length 258) can be represented
         * in two different ways: code 284 + 5 bits or code 285, so we
         * overwrite length_code[255] to use the best encoding:
         */
        zip_length_code[length-1] = code;
    
        /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
        dist = 0;
        for(code = 0 ; code < 16; code++) {
        zip_base_dist[code] = dist;
        for(n = 0; n < (1<<zip_extra_dbits[code]); n++) {
            zip_dist_code[dist++] = code;
        }
        }
        // Assert (dist == 256, "ct_init: dist != 256");
        dist >>= 7; // from now on, all distances are divided by 128
        for( ; code < zip_D_CODES; code++) {
        zip_base_dist[code] = dist << 7;
        for(n = 0; n < (1<<(zip_extra_dbits[code]-7)); n++)
            zip_dist_code[256 + dist++] = code;
        }
        // Assert (dist == 256, "ct_init: 256+dist != 512");
    
        // Construct the codes of the static literal tree
        for(bits = 0; bits <= zip_MAX_BITS; bits++)
        zip_bl_count[bits] = 0;
        n = 0;
        while(n <= 143) { zip_static_ltree[n++].dl = 8; zip_bl_count[8]++; }
        while(n <= 255) { zip_static_ltree[n++].dl = 9; zip_bl_count[9]++; }
        while(n <= 279) { zip_static_ltree[n++].dl = 7; zip_bl_count[7]++; }
        while(n <= 287) { zip_static_ltree[n++].dl = 8; zip_bl_count[8]++; }
        /* Codes 286 and 287 do not exist, but we must include them in the
         * tree construction to get a canonical Huffman tree (longest code
         * all ones)
         */
        zip_gen_codes(zip_static_ltree, zip_L_CODES + 1);
    
        /* The static distance tree is trivial: */
        for(n = 0; n < zip_D_CODES; n++) {
        zip_static_dtree[n].dl = 5;
        zip_static_dtree[n].fc = zip_bi_reverse(n, 5);
        }
    
        // Initialize the first block of the first file:
        zip_init_block();
    }
    
    /* ==========================================================================
     * Initialize a new block.
     */
    var zip_init_block = function() {
        var n; // iterates over tree elements
    
        // Initialize the trees.
        for(n = 0; n < zip_L_CODES;  n++) zip_dyn_ltree[n].fc = 0;
        for(n = 0; n < zip_D_CODES;  n++) zip_dyn_dtree[n].fc = 0;
        for(n = 0; n < zip_BL_CODES; n++) zip_bl_tree[n].fc = 0;
    
        zip_dyn_ltree[zip_END_BLOCK].fc = 1;
        zip_opt_len = zip_static_len = 0;
        zip_last_lit = zip_last_dist = zip_last_flags = 0;
        zip_flags = 0;
        zip_flag_bit = 1;
    }
    
    /* ==========================================================================
     * 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).
     */
    var zip_pqdownheap = function(
        tree,   // the tree to restore
        k) {    // node to move down
        var v = zip_heap[k];
        var j = k << 1; // left son of k
    
        while(j <= zip_heap_len) {
        // Set j to the smallest of the two sons:
        if(j < zip_heap_len &&
           zip_SMALLER(tree, zip_heap[j + 1], zip_heap[j]))
            j++;
    
        // Exit if v is smaller than both sons
        if(zip_SMALLER(tree, v, zip_heap[j]))
            break;
    
        // Exchange v with the smallest son
        zip_heap[k] = zip_heap[j];
        k = j;
    
        // And continue down the tree, setting j to the left son of k
        j <<= 1;
        }
        zip_heap[k] = v;
    }
    
    /* ==========================================================================
     * Compute the optimal bit lengths for a tree and update the total bit length
     * for the current block.
     * IN assertion: the fields freq and dad are set, heap[heap_max] and
     *    above are the tree nodes sorted by increasing frequency.
     * OUT assertions: the field len is set to the optimal bit length, the
     *     array bl_count contains the frequencies for each bit length.
     *     The length opt_len is updated; static_len is also updated if stree is
     *     not null.
     */
    var zip_gen_bitlen = function(desc) { // the tree descriptor
        var tree                = desc.dyn_tree;
        var extra               = desc.extra_bits;
        var base                = desc.extra_base;
        var max_code    = desc.max_code;
        var max_length  = desc.max_length;
        var stree               = desc.static_tree;
        var h;          // heap index
        var n, m;               // iterate over the tree elements
        var bits;               // bit length
        var xbits;              // extra bits
        var f;          // frequency
        var overflow = 0;       // number of elements with bit length too large
    
        for(bits = 0; bits <= zip_MAX_BITS; bits++)
        zip_bl_count[bits] = 0;
    
        /* In a first pass, compute the optimal bit lengths (which may
         * overflow in the case of the bit length tree).
         */
        tree[zip_heap[zip_heap_max]].dl = 0; // root of the heap
    
        for(h = zip_heap_max + 1; h < zip_HEAP_SIZE; h++) {
        n = zip_heap[h];
        bits = tree[tree[n].dl].dl + 1;
        if(bits > max_length) {
            bits = max_length;
            overflow++;
        }
        tree[n].dl = bits;
        // We overwrite tree[n].dl which is no longer needed
    
        if(n > max_code)
            continue; // not a leaf node
    
        zip_bl_count[bits]++;
        xbits = 0;
        if(n >= base)
            xbits = extra[n - base];
        f = tree[n].fc;
        zip_opt_len += f * (bits + xbits);
        if(stree != null)
            zip_static_len += f * (stree[n].dl + xbits);
        }
        if(overflow == 0)
        return;
    
        // This happens for example on obj2 and pic of the Calgary corpus
    
        // Find the first bit length which could increase:
        do {
        bits = max_length - 1;
        while(zip_bl_count[bits] == 0)
            bits--;
        zip_bl_count[bits]--;           // move one leaf down the tree
        zip_bl_count[bits + 1] += 2;    // move one overflow item as its brother
        zip_bl_count[max_length]--;
        /* The brother of the overflow item also moves one step up,
         * but this does not affect bl_count[max_length]
         */
        overflow -= 2;
        } while(overflow > 0);
    
        /* Now recompute all bit lengths, scanning in increasing frequency.
         * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
         * lengths instead of fixing only the wrong ones. This idea is taken
         * from 'ar' written by Haruhiko Okumura.)
         */
        for(bits = max_length; bits != 0; bits--) {
        n = zip_bl_count[bits];
        while(n != 0) {
            m = zip_heap[--h];
            if(m > max_code)
                continue;
            if(tree[m].dl != bits) {
                zip_opt_len += (bits - tree[m].dl) * tree[m].fc;
                tree[m].fc = bits;
            }
            n--;
        }
        }
    }
    
      /* ==========================================================================
       * Generate the codes for a given tree and bit counts (which need not be
       * optimal).
       * IN assertion: the array bl_count contains the bit length statistics for
       * the given tree and the field len is set for all tree elements.
       * OUT assertion: the field code is set for all tree elements of non
       *     zero code length.
       */
    var zip_gen_codes = function(tree,  // the tree to decorate
                   max_code) {  // largest code with non zero frequency
        var next_code = new Array(zip_MAX_BITS+1); // next code value for each bit length
        var code = 0;           // running code value
        var bits;                       // bit index
        var n;                  // code index
    
        /* The distribution counts are first used to generate the code values
         * without bit reversal.
         */
        for(bits = 1; bits <= zip_MAX_BITS; bits++) {
        code = ((code + zip_bl_count[bits-1]) << 1);
        next_code[bits] = code;
        }
    
        /* Check that the bit counts in bl_count are consistent. The last code
         * must be all ones.
         */
    //    Assert (code + encoder->bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
    //      "inconsistent bit counts");
    //    Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
    
        for(n = 0; n <= max_code; n++) {
        var len = tree[n].dl;
        if(len == 0)
            continue;
        // Now reverse the bits
        tree[n].fc = zip_bi_reverse(next_code[len]++, len);
    
    //      Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
    //    n, (isgraph(n) ? n : ' '), len, tree[n].fc, next_code[len]-1));
        }
    }
    
    /* ==========================================================================
     * Construct one Huffman tree and assigns the code bit strings and lengths.
     * Update the total bit length for the current block.
     * IN assertion: the field freq is set for all tree elements.
     * OUT assertions: the fields len and code are set to the optimal bit length
     *     and corresponding code. The length opt_len is updated; static_len is
     *     also updated if stree is not null. The field max_code is set.
     */
    var zip_build_tree = function(desc) { // the tree descriptor
        var tree        = desc.dyn_tree;
        var stree       = desc.static_tree;
        var elems       = desc.elems;
        var n, m;               // iterate over heap elements
        var max_code = -1;      // largest code with non zero frequency
        var node = elems;       // next internal node of the tree
    
        /* Construct the initial heap, with least frequent element in
         * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
         * heap[0] is not used.
         */
        zip_heap_len = 0;
        zip_heap_max = zip_HEAP_SIZE;
    
        for(n = 0; n < elems; n++) {
        if(tree[n].fc != 0) {
            zip_heap[++zip_heap_len] = max_code = n;
            zip_depth[n] = 0;
        } else
            tree[n].dl = 0;
        }
    
        /* The pkzip format requires that at least one distance code exists,
         * and that at least one bit should be sent even if there is only one
         * possible code. So to avoid special checks later on we force at least
         * two codes of non zero frequency.
         */
        while(zip_heap_len < 2) {
        var xnew = zip_heap[++zip_heap_len] = (max_code < 2 ? ++max_code : 0);
        tree[xnew].fc = 1;
        zip_depth[xnew] = 0;
        zip_opt_len--;
        if(stree != null)
            zip_static_len -= stree[xnew].dl;
        // new is 0 or 1 so it does not have extra bits
        }
        desc.max_code = max_code;
    
        /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
         * establish sub-heaps of increasing lengths:
         */
        for(n = zip_heap_len >> 1; n >= 1; n--)
        zip_pqdownheap(tree, n);
    
        /* Construct the Huffman tree by repeatedly combining the least two
         * frequent nodes.
         */
        do {
        n = zip_heap[zip_SMALLEST];
        zip_heap[zip_SMALLEST] = zip_heap[zip_heap_len--];
        zip_pqdownheap(tree, zip_SMALLEST);
    
        m = zip_heap[zip_SMALLEST];  // m = node of next least frequency
    
        // keep the nodes sorted by frequency
        zip_heap[--zip_heap_max] = n;
        zip_heap[--zip_heap_max] = m;
    
        // Create a new node father of n and m
        tree[node].fc = tree[n].fc + tree[m].fc;
    //  depth[node] = (char)(MAX(depth[n], depth[m]) + 1);
        if(zip_depth[n] > zip_depth[m] + 1)
            zip_depth[node] = zip_depth[n];
        else
            zip_depth[node] = zip_depth[m] + 1;
        tree[n].dl = tree[m].dl = node;
    
        // and insert the new node in the heap
        zip_heap[zip_SMALLEST] = node++;
        zip_pqdownheap(tree, zip_SMALLEST);
    
        } while(zip_heap_len >= 2);
    
        zip_heap[--zip_heap_max] = zip_heap[zip_SMALLEST];
    
        /* At this point, the fields freq and dad are set. We can now
         * generate the bit lengths.
         */
        zip_gen_bitlen(desc);
    
        // The field len is now set, we can generate the bit codes
        zip_gen_codes(tree, max_code);
    }
    
    /* ==========================================================================
     * Scan a literal or distance tree to determine the frequencies of the codes
     * in the bit length tree. Updates opt_len to take into account the repeat
     * counts. (The contribution of the bit length codes will be added later
     * during the construction of bl_tree.)
     */
    var zip_scan_tree = function(tree,// the tree to be scanned
                       max_code) {  // and its largest code of non zero frequency
        var n;                  // iterates over all tree elements
        var prevlen = -1;               // last emitted length
        var curlen;                     // length of current code
        var nextlen = tree[0].dl;       // length of next code
        var count = 0;          // repeat count of the current code
        var max_count = 7;              // max repeat count
        var min_count = 4;              // min repeat count
    
        if(nextlen == 0) {
        max_count = 138;
        min_count = 3;
        }
        tree[max_code + 1].dl = 0xffff; // guard
    
        for(n = 0; n <= max_code; n++) {
        curlen = nextlen;
        nextlen = tree[n + 1].dl;
        if(++count < max_count && curlen == nextlen)
            continue;
        else if(count < min_count)
            zip_bl_tree[curlen].fc += count;
        else if(curlen != 0) {
            if(curlen != prevlen)
                zip_bl_tree[curlen].fc++;
            zip_bl_tree[zip_REP_3_6].fc++;
        } else if(count <= 10)
            zip_bl_tree[zip_REPZ_3_10].fc++;
        else
            zip_bl_tree[zip_REPZ_11_138].fc++;
        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;
        }
        }
    }
    
      /* ==========================================================================
       * Send a literal or distance tree in compressed form, using the codes in
       * bl_tree.
       */
    var zip_send_tree = function(tree, // the tree to be scanned
                   max_code) { // and its largest code of non zero frequency
        var n;                  // iterates over all tree elements
        var prevlen = -1;               // last emitted length
        var curlen;                     // length of current code
        var nextlen = tree[0].dl;       // length of next code
        var count = 0;          // repeat count of the current code
        var max_count = 7;              // max repeat count
        var min_count = 4;              // min repeat count
    
        /* tree[max_code+1].dl = -1; */  /* guard already set */
        if(nextlen == 0) {
          max_count = 138;
          min_count = 3;
        }
    
        for(n = 0; n <= max_code; n++) {
        curlen = nextlen;
        nextlen = tree[n+1].dl;
        if(++count < max_count && curlen == nextlen) {
            continue;
        } else if(count < min_count) {
            do { zip_SEND_CODE(curlen, zip_bl_tree); } while(--count != 0);
        } else if(curlen != 0) {
            if(curlen != prevlen) {
                zip_SEND_CODE(curlen, zip_bl_tree);
                count--;
            }
            // Assert(count >= 3 && count <= 6, " 3_6?");
            zip_SEND_CODE(zip_REP_3_6, zip_bl_tree);
            zip_send_bits(count - 3, 2);
        } else if(count <= 10) {
            zip_SEND_CODE(zip_REPZ_3_10, zip_bl_tree);
            zip_send_bits(count-3, 3);
        } else {
            zip_SEND_CODE(zip_REPZ_11_138, zip_bl_tree);
            zip_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;
        }
        }
    }
    
    /* ==========================================================================
     * Construct the Huffman tree for the bit lengths and return the index in
     * bl_order of the last bit length code to send.
     */
    var zip_build_bl_tree = function() {
        var max_blindex;  // index of last bit length code of non zero freq
    
        // Determine the bit length frequencies for literal and distance trees
        zip_scan_tree(zip_dyn_ltree, zip_l_desc.max_code);
        zip_scan_tree(zip_dyn_dtree, zip_d_desc.max_code);
    
        // Build the bit length tree:
        zip_build_tree(zip_bl_desc);
        /* 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 = zip_BL_CODES-1; max_blindex >= 3; max_blindex--) {
        if(zip_bl_tree[zip_bl_order[max_blindex]].dl != 0) break;
        }
        /* Update opt_len to include the bit length tree and counts */
        zip_opt_len += 3*(max_blindex+1) + 5+5+4;
    //    Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",
    //      encoder->opt_len, encoder->static_len));
    
        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.
     */
    var zip_send_all_trees = function(lcodes, dcodes, blcodes) { // number of codes for each tree
        var rank; // index in bl_order
    
    //    Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
    //    Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
    //      "too many codes");
    //    Tracev((stderr, "\nbl counts: "));
        zip_send_bits(lcodes-257, 5); // not +255 as stated in appnote.txt
        zip_send_bits(dcodes-1,   5);
        zip_send_bits(blcodes-4,  4); // not -3 as stated in appnote.txt
        for(rank = 0; rank < blcodes; rank++) {
    //      Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
        zip_send_bits(zip_bl_tree[zip_bl_order[rank]].dl, 3);
        }
    
        // send the literal tree
        zip_send_tree(zip_dyn_ltree,lcodes-1);
    
        // send the distance tree
        zip_send_tree(zip_dyn_dtree,dcodes-1);
    }
    
    /* ==========================================================================
     * Determine the best encoding for the current block: dynamic trees, static
     * trees or store, and output the encoded block to the zip file.
     */
    var zip_flush_block = function(eof) { // true if this is the last block for a file
        var opt_lenb, static_lenb; // opt_len and static_len in bytes
        var max_blindex;        // index of last bit length code of non zero freq
        var stored_len; // length of input block
    
        stored_len = zip_strstart - zip_block_start;
        zip_flag_buf[zip_last_flags] = zip_flags; // Save the flags for the last 8 items
    
        // Construct the literal and distance trees
        zip_build_tree(zip_l_desc);
    //    Tracev((stderr, "\nlit data: dyn %ld, stat %ld",
    //      encoder->opt_len, encoder->static_len));
    
        zip_build_tree(zip_d_desc);
    //    Tracev((stderr, "\ndist data: dyn %ld, stat %ld",
    //      encoder->opt_len, encoder->static_len));
        /* 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 = zip_build_bl_tree();
    
        // Determine the best encoding. Compute first the block length in bytes
        opt_lenb        = (zip_opt_len   +3+7)>>3;
        static_lenb = (zip_static_len+3+7)>>3;
    
    //    Trace((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ",
    //     opt_lenb, encoder->opt_len,
    //     static_lenb, encoder->static_len, stored_len,
    //     encoder->last_lit, encoder->last_dist));
    
        if(static_lenb <= opt_lenb)
        opt_lenb = static_lenb;
        if(stored_len + 4 <= opt_lenb // 4: two words for the lengths
           && zip_block_start >= 0) {
        var i;
    
        /* 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.
         */
        zip_send_bits((zip_STORED_BLOCK<<1)+eof, 3);  /* send block type */
        zip_bi_windup();                 /* align on byte boundary */
        zip_put_short(stored_len);
        zip_put_short(~stored_len);
    
          // copy block
    /*
          p = &window[block_start];
          for(i = 0; i < stored_len; i++)
        put_byte(p[i]);
    */
        for(i = 0; i < stored_len; i++)
            zip_put_byte(zip_window[zip_block_start + i]);
    
        } else if(static_lenb == opt_lenb) {
        zip_send_bits((zip_STATIC_TREES<<1)+eof, 3);
        zip_compress_block(zip_static_ltree, zip_static_dtree);
        } else {
        zip_send_bits((zip_DYN_TREES<<1)+eof, 3);
        zip_send_all_trees(zip_l_desc.max_code+1,
                           zip_d_desc.max_code+1,
                           max_blindex+1);
        zip_compress_block(zip_dyn_ltree, zip_dyn_dtree);
        }
    
        zip_init_block();
    
        if(eof != 0)
        zip_bi_windup();
    }
    
    /* ==========================================================================
     * Save the match info and tally the frequency counts. Return true if
     * the current block must be flushed.
     */
    var zip_ct_tally = function(
        dist, // distance of matched string
        lc) { // match length-MIN_MATCH or unmatched char (if dist==0)
        zip_l_buf[zip_last_lit++] = lc;
        if(dist == 0) {
        // lc is the unmatched char
        zip_dyn_ltree[lc].fc++;
        } else {
        // Here, lc is the match length - MIN_MATCH
        dist--;             // dist = match distance - 1
    //      Assert((ush)dist < (ush)MAX_DIST &&
    //       (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
    //       (ush)D_CODE(dist) < (ush)D_CODES,  "ct_tally: bad match");
    
        zip_dyn_ltree[zip_length_code[lc]+zip_LITERALS+1].fc++;
        zip_dyn_dtree[zip_D_CODE(dist)].fc++;
    
        zip_d_buf[zip_last_dist++] = dist;
        zip_flags |= zip_flag_bit;
        }
        zip_flag_bit <<= 1;
    
        // Output the flags if they fill a byte
        if((zip_last_lit & 7) == 0) {
        zip_flag_buf[zip_last_flags++] = zip_flags;
        zip_flags = 0;
        zip_flag_bit = 1;
        }
        // Try to guess if it is profitable to stop the current block here
        if(zip_compr_level > 2 && (zip_last_lit & 0xfff) == 0) {
        // Compute an upper bound for the compressed length
        var out_length = zip_last_lit * 8;
        var in_length = zip_strstart - zip_block_start;
        var dcode;
    
        for(dcode = 0; dcode < zip_D_CODES; dcode++) {
            out_length += zip_dyn_dtree[dcode].fc * (5 + zip_extra_dbits[dcode]);
        }
        out_length >>= 3;
    //      Trace((stderr,"\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ",
    //       encoder->last_lit, encoder->last_dist, in_length, out_length,
    //       100L - out_length*100L/in_length));
        if(zip_last_dist < parseInt(zip_last_lit/2) &&
           out_length < parseInt(in_length/2))
            return true;
        }
        return (zip_last_lit == zip_LIT_BUFSIZE-1 ||
            zip_last_dist == zip_DIST_BUFSIZE);
        /* 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
       */
    var zip_compress_block = function(
        ltree,  // literal tree
        dtree) {        // distance tree
        var dist;               // distance of matched string
        var lc;         // match length or unmatched char (if dist == 0)
        var lx = 0;             // running index in l_buf
        var dx = 0;             // running index in d_buf
        var fx = 0;             // running index in flag_buf
        var flag = 0;   // current flags
        var code;               // the code to send
        var extra;              // number of extra bits to send
    
        if(zip_last_lit != 0) do {
        if((lx & 7) == 0)
            flag = zip_flag_buf[fx++];
        lc = zip_l_buf[lx++] & 0xff;
        if((flag & 1) == 0) {
            zip_SEND_CODE(lc, ltree); /* send a literal byte */
    //  Tracecv(isgraph(lc), (stderr," '%c' ", lc));
        } else {
            // Here, lc is the match length - MIN_MATCH
            code = zip_length_code[lc];
            zip_SEND_CODE(code+zip_LITERALS+1, ltree); // send the length code
            extra = zip_extra_lbits[code];
            if(extra != 0) {
                lc -= zip_base_length[code];
                zip_send_bits(lc, extra); // send the extra length bits
            }
            dist = zip_d_buf[dx++];
            // Here, dist is the match distance - 1
            code = zip_D_CODE(dist);
    //  Assert (code < D_CODES, "bad d_code");
    
            zip_SEND_CODE(code, dtree);   // send the distance code
            extra = zip_extra_dbits[code];
            if(extra != 0) {
                dist -= zip_base_dist[code];
                zip_send_bits(dist, extra);   // send the extra distance bits
            }
        } // literal or match pair ?
        flag >>= 1;
        } while(lx < zip_last_lit);
    
        zip_SEND_CODE(zip_END_BLOCK, ltree);
    }
    
    /* ==========================================================================
     * Send a value on a given number of bits.
     * IN assertion: length <= 16 and value fits in length bits.
     */
    var zip_Buf_size = 16; // bit size of bi_buf
    var zip_send_bits = function(
        value,  // value to send
        length) {       // number of bits
        /* If not enough room in bi_buf, use (valid) bits from bi_buf and
         * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
         * unused bits in value.
         */
        if(zip_bi_valid > zip_Buf_size - length) {
        zip_bi_buf |= (value << zip_bi_valid);
        zip_put_short(zip_bi_buf);
        zip_bi_buf = (value >> (zip_Buf_size - zip_bi_valid));
        zip_bi_valid += length - zip_Buf_size;
        } else {
        zip_bi_buf |= value << zip_bi_valid;
        zip_bi_valid += length;
        }
    }
    
    /* ==========================================================================
     * Reverse the first len bits of a code, using straightforward code (a faster
     * method would use a table)
     * IN assertion: 1 <= len <= 15
     */
    var zip_bi_reverse = function(
        code,   // the value to invert
        len) {  // its bit length
        var res = 0;
        do {
        res |= code & 1;
        code >>= 1;
        res <<= 1;
        } while(--len > 0);
        return res >> 1;
    }
    
    /* ==========================================================================
     * Write out any remaining bits in an incomplete byte.
     */
    var zip_bi_windup = function() {
        if(zip_bi_valid > 8) {
        zip_put_short(zip_bi_buf);
        } else if(zip_bi_valid > 0) {
        zip_put_byte(zip_bi_buf);
        }
        zip_bi_buf = 0;
        zip_bi_valid = 0;
    }
    
    var zip_qoutbuf = function() {
        if(zip_outcnt != 0) {
        var q, i;
        q = zip_new_queue();
        if(zip_qhead == null)
            zip_qhead = zip_qtail = q;
        else
            zip_qtail = zip_qtail.next = q;
        q.len = zip_outcnt - zip_outoff;
    //      System.arraycopy(zip_outbuf, zip_outoff, q.ptr, 0, q.len);
        for(i = 0; i < q.len; i++)
            q.ptr[i] = zip_outbuf[zip_outoff + i];
        zip_outcnt = zip_outoff = 0;
        }
    }
    
    var zip_deflate = function(str, level) {
        var i, j;
    
        zip_deflate_data = str;
        zip_deflate_pos = 0;
        if(typeof level == "undefined")
        level = zip_DEFAULT_LEVEL;
        zip_deflate_start(level);
    
        var buff = new Array(1024);
        var aout = [];
        while((i = zip_deflate_internal(buff, 0, buff.length)) > 0) {
        var cbuf = new Array(i);
        for(j = 0; j < i; j++){
            cbuf[j] = String.fromCharCode(buff[j]);
        }
        aout[aout.length] = cbuf.join("");
        }
        zip_deflate_data = null; // G.C.
        return aout.join("");
    }
    
    if (! ctx.RawDeflate) ctx.RawDeflate = {};
    ctx.RawDeflate.deflate = zip_deflate;
    
    })(foo);
    
    // Copyright (c) 2013 Pieroxy <pieroxy@pieroxy.net>
    // This work is free. You can redistribute it and/or modify it
    // under the terms of the WTFPL, Version 2
    // For more information see LICENSE.txt or http://www.wtfpl.net/
    //
    // For more information, the home page:
    // http://pieroxy.net/blog/pages/lz-string/testing.html
    //
    // LZ-based compression algorithm, version 1.3.3
    foo.LZString = {
      
      
      // private property
      _keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
      _f : String.fromCharCode,
      
      compressToBase64 : function (input) {
        if (input == null) return "";
        var output = "";
        var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
        var i = 0;
        
        input = LZString.compress(input);
        
        while (i < input.length*2) {
          
          if (i%2==0) {
            chr1 = input.charCodeAt(i/2) >> 8;
            chr2 = input.charCodeAt(i/2) & 255;
            if (i/2+1 < input.length) 
              chr3 = input.charCodeAt(i/2+1) >> 8;
            else 
              chr3 = NaN;
          } else {
            chr1 = input.charCodeAt((i-1)/2) & 255;
            if ((i+1)/2 < input.length) {
              chr2 = input.charCodeAt((i+1)/2) >> 8;
              chr3 = input.charCodeAt((i+1)/2) & 255;
            } else 
              chr2=chr3=NaN;
          }
          i+=3;
          
          enc1 = chr1 >> 2;
          enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
          enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
          enc4 = chr3 & 63;
          
          if (isNaN(chr2)) {
            enc3 = enc4 = 64;
          } else if (isNaN(chr3)) {
            enc4 = 64;
          }
          
          output = output +
            LZString._keyStr.charAt(enc1) + LZString._keyStr.charAt(enc2) +
              LZString._keyStr.charAt(enc3) + LZString._keyStr.charAt(enc4);
          
        }
        
        return output;
      },
      
      decompressFromBase64 : function (input) {
        if (input == null) return "";
        var output = "",
            ol = 0, 
            output_,
            chr1, chr2, chr3,
            enc1, enc2, enc3, enc4,
            i = 0, f=LZString._f;
        
        input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
        
        while (i < input.length) {
          
          enc1 = LZString._keyStr.indexOf(input.charAt(i++));
          enc2 = LZString._keyStr.indexOf(input.charAt(i++));
          enc3 = LZString._keyStr.indexOf(input.charAt(i++));
          enc4 = LZString._keyStr.indexOf(input.charAt(i++));
          
          chr1 = (enc1 << 2) | (enc2 >> 4);
          chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
          chr3 = ((enc3 & 3) << 6) | enc4;
          
          if (ol%2==0) {
            output_ = chr1 << 8;
            
            if (enc3 != 64) {
              output += f(output_ | chr2);
            }
            if (enc4 != 64) {
              output_ = chr3 << 8;
            }
          } else {
            output = output + f(output_ | chr1);
            
            if (enc3 != 64) {
              output_ = chr2 << 8;
            }
            if (enc4 != 64) {
              output += f(output_ | chr3);
            }
          }
          ol+=3;
        }
        
        return LZString.decompress(output);
        
      },
    
      compressToUTF16 : function (input) {
        if (input == null) return "";
        var output = "",
            i,c,
            current,
            status = 0,
            f = LZString._f;
        
        input = LZString.compress(input);
        
        for (i=0 ; i<input.length ; i++) {
          c = input.charCodeAt(i);
          switch (status++) {
            case 0:
              output += f((c >> 1)+32);
              current = (c & 1) << 14;
              break;
            case 1:
              output += f((current + (c >> 2))+32);
              current = (c & 3) << 13;
              break;
            case 2:
              output += f((current + (c >> 3))+32);
              current = (c & 7) << 12;
              break;
            case 3:
              output += f((current + (c >> 4))+32);
              current = (c & 15) << 11;
              break;
            case 4:
              output += f((current + (c >> 5))+32);
              current = (c & 31) << 10;
              break;
            case 5:
              output += f((current + (c >> 6))+32);
              current = (c & 63) << 9;
              break;
            case 6:
              output += f((current + (c >> 7))+32);
              current = (c & 127) << 8;
              break;
            case 7:
              output += f((current + (c >> 8))+32);
              current = (c & 255) << 7;
              break;
            case 8:
              output += f((current + (c >> 9))+32);
              current = (c & 511) << 6;
              break;
            case 9:
              output += f((current + (c >> 10))+32);
              current = (c & 1023) << 5;
              break;
            case 10:
              output += f((current + (c >> 11))+32);
              current = (c & 2047) << 4;
              break;
            case 11:
              output += f((current + (c >> 12))+32);
              current = (c & 4095) << 3;
              break;
            case 12:
              output += f((current + (c >> 13))+32);
              current = (c & 8191) << 2;
              break;
            case 13:
              output += f((current + (c >> 14))+32);
              current = (c & 16383) << 1;
              break;
            case 14:
              output += f((current + (c >> 15))+32, (c & 32767)+32);
              status = 0;
              break;
          }
        }
        
        return output + f(current + 32);
      },
      
    
      decompressFromUTF16 : function (input) {
        if (input == null) return "";
        var output = "",
            current,c,
            status=0,
            i = 0,
            f = LZString._f;
        
        while (i < input.length) {
          c = input.charCodeAt(i) - 32;
          
          switch (status++) {
            case 0:
              current = c << 1;
              break;
            case 1:
              output += f(current | (c >> 14));
              current = (c&16383) << 2;
              break;
            case 2:
              output += f(current | (c >> 13));
              current = (c&8191) << 3;
              break;
            case 3:
              output += f(current | (c >> 12));
              current = (c&4095) << 4;
              break;
            case 4:
              output += f(current | (c >> 11));
              current = (c&2047) << 5;
              break;
            case 5:
              output += f(current | (c >> 10));
              current = (c&1023) << 6;
              break;
            case 6:
              output += f(current | (c >> 9));
              current = (c&511) << 7;
              break;
            case 7:
              output += f(current | (c >> 8));
              current = (c&255) << 8;
              break;
            case 8:
              output += f(current | (c >> 7));
              current = (c&127) << 9;
              break;
            case 9:
              output += f(current | (c >> 6));
              current = (c&63) << 10;
              break;
            case 10:
              output += f(current | (c >> 5));
              current = (c&31) << 11;
              break;
            case 11:
              output += f(current | (c >> 4));
              current = (c&15) << 12;
              break;
            case 12:
              output += f(current | (c >> 3));
              current = (c&7) << 13;
              break;
            case 13:
              output += f(current | (c >> 2));
              current = (c&3) << 14;
              break;
            case 14:
              output += f(current | (c >> 1));
              current = (c&1) << 15;
              break;
            case 15:
              output += f(current | c);
              status=0;
              break;
          }
          
          
          i++;
        }
        
        return LZString.decompress(output);
        //return output;
        
      },
    
    
      
      compress: function (uncompressed) {
        if (uncompressed == null) return "";
        var i, value,
            context_dictionary= {},
            context_dictionaryToCreate= {},
            context_c="",
            context_wc="",
            context_w="",
            context_enlargeIn= 2, // Compensate for the first entry which should not count
            context_dictSize= 3,
            context_numBits= 2,
            context_data_string="", 
            context_data_val=0, 
            context_data_position=0,
            ii,
            f=LZString._f;
        
        for (ii = 0; ii < uncompressed.length; ii += 1) {
          context_c = uncompressed.charAt(ii);
          if (!Object.prototype.hasOwnProperty.call(context_dictionary,context_c)) {
            context_dictionary[context_c] = context_dictSize++;
            context_dictionaryToCreate[context_c] = true;
          }
          
          context_wc = context_w + context_c;
          if (Object.prototype.hasOwnProperty.call(context_dictionary,context_wc)) {
            context_w = context_wc;
          } else {
            if (Object.prototype.hasOwnProperty.call(context_dictionaryToCreate,context_w)) {
              if (context_w.charCodeAt(0)<256) {
                for (i=0 ; i<context_numBits ; i++) {
                  context_data_val = (context_data_val << 1);
                  if (context_data_position == 15) {
                    context_data_position = 0;
                    context_data_string += f(context_data_val);
                    context_data_val = 0;
                  } else {
                    context_data_position++;
                  }
                }
                value = context_w.charCodeAt(0);
                for (i=0 ; i<8 ; i++) {
                  context_data_val = (context_data_val << 1) | (value&1);
                  if (context_data_position == 15) {
                    context_data_position = 0;
                    context_data_string += f(context_data_val);
                    context_data_val = 0;
                  } else {
                    context_data_position++;
                  }
                  value = value >> 1;
                }
              } else {
                value = 1;
                for (i=0 ; i<context_numBits ; i++) {
                  context_data_val = (context_data_val << 1) | value;
                  if (context_data_position == 15) {
                    context_data_position = 0;
                    context_data_string += f(context_data_val);
                    context_data_val = 0;
                  } else {
                    context_data_position++;
                  }
                  value = 0;
                }
                value = context_w.charCodeAt(0);
                for (i=0 ; i<16 ; i++) {
                  context_data_val = (context_data_val << 1) | (value&1);
                  if (context_data_position == 15) {
                    context_data_position = 0;
                    context_data_string += f(context_data_val);
                    context_data_val = 0;
                  } else {
                    context_data_position++;
                  }
                  value = value >> 1;
                }
              }
              context_enlargeIn--;
              if (context_enlargeIn == 0) {
                context_enlargeIn = Math.pow(2, context_numBits);
                context_numBits++;
              }
              delete context_dictionaryToCreate[context_w];
            } else {
              value = context_dictionary[context_w];
              for (i=0 ; i<context_numBits ; i++) {
                context_data_val = (context_data_val << 1) | (value&1);
                if (context_data_position == 15) {
                  context_data_position = 0;
                  context_data_string += f(context_data_val);
                  context_data_val = 0;
                } else {
                  context_data_position++;
                }
                value = value >> 1;
              }
              
              
            }
            context_enlargeIn--;
            if (context_enlargeIn == 0) {
              context_enlargeIn = Math.pow(2, context_numBits);
              context_numBits++;
            }
            // Add wc to the dictionary.
            context_dictionary[context_wc] = context_dictSize++;
            context_w = String(context_c);
          }
        }
        
        // Output the code for w.
        if (context_w !== "") {
          if (Object.prototype.hasOwnProperty.call(context_dictionaryToCreate,context_w)) {
            if (context_w.charCodeAt(0)<256) {
              for (i=0 ; i<context_numBits ; i++) {
                context_data_val = (context_data_val << 1);
                if (context_data_position == 15) {
                  context_data_position = 0;
                  context_data_string += f(context_data_val);
                  context_data_val = 0;
                } else {
                  context_data_position++;
                }
              }
              value = context_w.charCodeAt(0);
              for (i=0 ; i<8 ; i++) {
                context_data_val = (context_data_val << 1) | (value&1);
                if (context_data_position == 15) {
                  context_data_position = 0;
                  context_data_string += f(context_data_val);
                  context_data_val = 0;
                } else {
                  context_data_position++;
                }
                value = value >> 1;
              }
            } else {
              value = 1;
              for (i=0 ; i<context_numBits ; i++) {
                context_data_val = (context_data_val << 1) | value;
                if (context_data_position == 15) {
                  context_data_position = 0;
                  context_data_string += f(context_data_val);
                  context_data_val = 0;
                } else {
                  context_data_position++;
                }
                value = 0;
              }
              value = context_w.charCodeAt(0);
              for (i=0 ; i<16 ; i++) {
                context_data_val = (context_data_val << 1) | (value&1);
                if (context_data_position == 15) {
                  context_data_position = 0;
                  context_data_string += f(context_data_val);
                  context_data_val = 0;
                } else {
                  context_data_position++;
                }
                value = value >> 1;
              }
            }
            context_enlargeIn--;
            if (context_enlargeIn == 0) {
              context_enlargeIn = Math.pow(2, context_numBits);
              context_numBits++;
            }
            delete context_dictionaryToCreate[context_w];
          } else {
            value = context_dictionary[context_w];
            for (i=0 ; i<context_numBits ; i++) {
              context_data_val = (context_data_val << 1) | (value&1);
              if (context_data_position == 15) {
                context_data_position = 0;
                context_data_string += f(context_data_val);
                context_data_val = 0;
              } else {
                context_data_position++;
              }
              value = value >> 1;
            }
            
            
          }
          context_enlargeIn--;
          if (context_enlargeIn == 0) {
            context_enlargeIn = Math.pow(2, context_numBits);
            context_numBits++;
          }
        }
        
        // Mark the end of the stream
        value = 2;
        for (i=0 ; i<context_numBits ; i++) {
          context_data_val = (context_data_val << 1) | (value&1);
          if (context_data_position == 15) {
            context_data_position = 0;
            context_data_string += f(context_data_val);
            context_data_val = 0;
          } else {
            context_data_position++;
          }
          value = value >> 1;
        }
        
        // Flush the last char
        while (true) {
          context_data_val = (context_data_val << 1);
          if (context_data_position == 15) {
            context_data_string += f(context_data_val);
            break;
          }
          else context_data_position++;
        }
        return context_data_string;
      },
      
      decompress: function (compressed) {
        if (compressed == null) return "";
        if (compressed == "") return null;
        var dictionary = [],
            next,
            enlargeIn = 4,
            dictSize = 4,
            numBits = 3,
            entry = "",
            result = "",
            i,
            w,
            bits, resb, maxpower, power,
            c,
            f = LZString._f,
            data = {string:compressed, val:compressed.charCodeAt(0), position:32768, index:1};
        
        for (i = 0; i < 3; i += 1) {
          dictionary[i] = i;
        }
        
        bits = 0;
        maxpower = Math.pow(2,2);
        power=1;
        while (power!=maxpower) {
          resb = data.val & data.position;
          data.position >>= 1;
          if (data.position == 0) {
            data.position = 32768;
            data.val = data.string.charCodeAt(data.index++);
          }
          bits |= (resb>0 ? 1 : 0) * power;
          power <<= 1;
        }
        
        switch (next = bits) {
          case 0: 
              bits = 0;
              maxpower = Math.pow(2,8);
              power=1;
              while (power!=maxpower) {
                resb = data.val & data.position;
                data.position >>= 1;
                if (data.position == 0) {
                  data.position = 32768;
                  data.val = data.string.charCodeAt(data.index++);
                }
                bits |= (resb>0 ? 1 : 0) * power;
                power <<= 1;
              }
            c = f(bits);
            break;
          case 1: 
              bits = 0;
              maxpower = Math.pow(2,16);
              power=1;
              while (power!=maxpower) {
                resb = data.val & data.position;
                data.position >>= 1;
                if (data.position == 0) {
                  data.position = 32768;
                  data.val = data.string.charCodeAt(data.index++);
                }
                bits |= (resb>0 ? 1 : 0) * power;
                power <<= 1;
              }
            c = f(bits);
            break;
          case 2: 
            return "";
        }
        dictionary[3] = c;
        w = result = c;
        while (true) {
          if (data.index > data.string.length) {
            return "";
          }
          
          bits = 0;
          maxpower = Math.pow(2,numBits);
          power=1;
          while (power!=maxpower) {
            resb = data.val & data.position;
            data.position >>= 1;
            if (data.position == 0) {
              data.position = 32768;
              data.val = data.string.charCodeAt(data.index++);
            }
            bits |= (resb>0 ? 1 : 0) * power;
            power <<= 1;
          }
    
          switch (c = bits) {
            case 0: 
              bits = 0;
              maxpower = Math.pow(2,8);
              power=1;
              while (power!=maxpower) {
                resb = data.val & data.position;
                data.position >>= 1;
                if (data.position == 0) {
                  data.position = 32768;
                  data.val = data.string.charCodeAt(data.index++);
                }
                bits |= (resb>0 ? 1 : 0) * power;
                power <<= 1;
              }
    
              dictionary[dictSize++] = f(bits);
              c = dictSize-1;
              enlargeIn--;
              break;
            case 1: 
              bits = 0;
              maxpower = Math.pow(2,16);
              power=1;
              while (power!=maxpower) {
                resb = data.val & data.position;
                data.position >>= 1;
                if (data.position == 0) {
                  data.position = 32768;
                  data.val = data.string.charCodeAt(data.index++);
                }
                bits |= (resb>0 ? 1 : 0) * power;
                power <<= 1;
              }
              dictionary[dictSize++] = f(bits);
              c = dictSize-1;
              enlargeIn--;
              break;
            case 2: 
              return result;
          }
          
          if (enlargeIn == 0) {
            enlargeIn = Math.pow(2, numBits);
            numBits++;
          }
          
          if (dictionary[c]) {
            entry = dictionary[c];
          } else {
            if (c === dictSize) {
              entry = w + w.charAt(0);
            } else {
              return null;
            }
          }
          result += entry;
          
          // Add w+entry[0] to the dictionary.
          dictionary[dictSize++] = w + entry.charAt(0);
          enlargeIn--;
          
          w = entry;
          
          if (enlargeIn == 0) {
            enlargeIn = Math.pow(2, numBits);
            numBits++;
          }
          
        }
      }
    };

Test runner

Ready to run.

Testing in
TestOps/sec
JSON + lzw
foo.LZString.compress(JSON.stringify(UFG_JSON))
ready
JSON + gzip
foo.RawDeflate.deflate(JSON.stringify(UFG_JSON))
ready

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.

  • Revision 1: published by Eloff on