VLEX/BPM-UI/node_modules/adm-zip/methods/deflater.js

/*
 * $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 JSDeflater(/*inbuff*/inbuf) {

	/* Copyright (C) 1999 Masanao Izumo <iz@onicos.co.jp>
	 * Version: 1.0.1
	 * LastModified: Dec 25 1999
	 */

	var WSIZE = 32768,		// Sliding Window size
		zip_STORED_BLOCK = 0,
		zip_STATIC_TREES = 1,
		zip_DYN_TREES = 2,
		zip_DEFAULT_LEVEL = 6,
		zip_FULL_SEARCH = true,
		zip_INBUFSIZ = 32768,	// Input buffer size
		zip_INBUF_EXTRA = 64,	// Extra buffer
		zip_OUTBUFSIZ = 1024 * 8,
		zip_window_size = 2 * WSIZE,
		MIN_MATCH = 3,
		MAX_MATCH = 258,
		zip_BITS = 16,
		LIT_BUFSIZE = 0x2000,
		zip_HASH_BITS = 13,
		zip_DIST_BUFSIZE = LIT_BUFSIZE,
		zip_HASH_SIZE = 1 << zip_HASH_BITS,
		zip_HASH_MASK = zip_HASH_SIZE - 1,
		zip_WMASK = WSIZE - 1,
		zip_NIL = 0, // Tail of hash chains
		zip_TOO_FAR = 4096,
		zip_MIN_LOOKAHEAD = MAX_MATCH + MIN_MATCH + 1,
		zip_MAX_DIST = WSIZE - zip_MIN_LOOKAHEAD,
		zip_SMALLEST = 1,
		zip_MAX_BITS = 15,
		zip_MAX_BL_BITS = 7,
		zip_LENGTH_CODES = 29,
		zip_LITERALS = 256,
		zip_END_BLOCK = 256,
		zip_L_CODES = zip_LITERALS + 1 + zip_LENGTH_CODES,
		zip_D_CODES = 30,
		zip_BL_CODES = 19,
		zip_REP_3_6 = 16,
		zip_REPZ_3_10 = 17,
		zip_REPZ_11_138 = 18,
		zip_HEAP_SIZE = 2 * zip_L_CODES + 1,
		zip_H_SHIFT = parseInt((zip_HASH_BITS + MIN_MATCH - 1) / MIN_MATCH);

	var zip_free_queue, zip_qhead, zip_qtail, zip_initflag, zip_outbuf = null, zip_outcnt, zip_outoff, zip_complete,
		zip_window, zip_d_buf, zip_l_buf, zip_prev, zip_bi_buf, zip_bi_valid, zip_block_start, zip_ins_h, zip_hash_head,
		zip_prev_match, zip_match_available, zip_match_length, zip_prev_length, zip_strstart, zip_match_start,
		zip_eofile,
		zip_lookahead, zip_max_chain_length, zip_max_lazy_match, zip_compr_level, zip_good_match, zip_nice_match,
		zip_dyn_ltree, zip_dyn_dtree, zip_static_ltree, zip_static_dtree, zip_bl_tree, zip_l_desc, zip_d_desc,
		zip_bl_desc,
		zip_bl_count, zip_heap, zip_heap_len, zip_heap_max, zip_depth, zip_length_code, zip_dist_code, zip_base_length,
		zip_base_dist, zip_flag_buf, zip_last_lit, zip_last_dist, zip_last_flags, zip_flags, zip_flag_bit, zip_opt_len,
		zip_static_len, zip_deflate_data, zip_deflate_pos;

	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 = [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 = [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 = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7];
	var zip_bl_order = [16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15];
	var zip_configuration_table = [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(MAX_MATCH - 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(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[WSIZE + i];
	};

	var zip_head2 = function (i, val) {
		return zip_prev[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 + 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[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_prev[WSIZE + j] = 0;
		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 * 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 < MIN_MATCH - 1; 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 + 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;

		do {
			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 = MAX_MATCH - (strendp - scanp);
			scanp = strendp - MAX_MATCH;

			if (len > best_len) {
				zip_match_start = cur_match;
				best_len = len;
				if (zip_FULL_SEARCH) {
					if (len >= 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 >= 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.
			 */
			for (n = 0; n < WSIZE; n++)
				zip_window[n] = zip_window[n + WSIZE];

			zip_match_start -= WSIZE;
			zip_strstart -= WSIZE;
			/* we now have strstart >= MAX_DIST: */
			zip_block_start -= WSIZE;

			for (n = 0; n < zip_HASH_SIZE; n++) {
				m = zip_head1(n);
				zip_head2(n, m >= WSIZE ? m - WSIZE : zip_NIL);
			}
			for (n = 0; n < 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 >= WSIZE ? m - WSIZE : zip_NIL);
			}
			more += 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 >= MIN_MATCH) {
				flush = zip_ct_tally(zip_strstart - zip_match_start,
					zip_match_length - 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;
					zip_ins_h = ((zip_ins_h << zip_H_SHIFT) ^ (zip_window[zip_strstart + 1] & 0xff)) & zip_HASH_MASK;
				}
			} 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 = 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 === 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 >= MIN_MATCH &&
				zip_match_length <= zip_prev_length) {
				var flush; // set if current block must be flushed
				flush = zip_ct_tally(zip_strstart - 1 - zip_prev_match,
					zip_prev_length - 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 = 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 = MIN_MATCH - 1;
			zip_match_length = 0;
		}
		else {
			zip_match_length = 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;
			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;
		}
		/* 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;
			}
		}
		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;
		}
		// 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.
		 */
		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);
		}
	};

	/* ==========================================================================
	 * 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;
			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;
		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
		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++) {
			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);
		zip_build_tree(zip_d_desc);
		/* 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;
		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
			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
			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;
			if (zip_last_dist < parseInt(zip_last_lit / 2) &&
				out_length < parseInt(in_length / 2))
				return true;
		}
		return (zip_last_lit === 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 */
			} 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);
				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;
			for (i = 0; i < q.len; i++)
				q.ptr[i] = zip_outbuf[zip_outoff + i];
			zip_outcnt = zip_outoff = 0;
		}
	};

	function deflate(buffData, level) {
		zip_deflate_data = buffData;
		zip_deflate_pos = 0;
		zip_deflate_start(level);

		var buff = new Array(1024),
			pages = [],
			totalSize = 0,
			i;

		for (i = 0; i < 1024; i++) buff[i] = 0;
		while ((i = zip_deflate_internal(buff, 0, buff.length)) > 0) {
			var buf = Buffer.alloc(i, buff.slice(0, i));
			pages.push(buf);
			totalSize += buf.length;
		}

		if (pages.length === 1) {
			return pages[0];
		}

		var result = Buffer.alloc(totalSize),
			index = 0;

		for (i = 0; i < pages.length; i++) {
			pages[i].copy(result, index);
			index = index + pages[i].length
		}

		return result;
	}

	return {
		deflate: function () {
			return deflate(inbuf, 8);
		}
	}
}

module.exports = function (/*Buffer*/inbuf) {

	var zlib = require("zlib");

	return {
		deflate: function () {
			return new JSDeflater(inbuf).deflate();
		},

		deflateAsync: function (/*Function*/callback) {
			var tmp = zlib.createDeflateRaw({chunkSize: (parseInt(inbuf.length / 1024) + 1) * 1024}),
				parts = [], total = 0;
			tmp.on('data', function (data) {
				parts.push(data);
				total += data.length;
			});
			tmp.on('end', function () {
				var buf = Buffer.alloc(total), written = 0;
				buf.fill(0);

				for (var i = 0; i < parts.length; i++) {
					var part = parts[i];
					part.copy(buf, written);
					written += part.length;
				}
				callback && callback(buf);
			});
			tmp.end(inbuf);
		}
	}
};