/*
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Copyright (c) 2013 Gildas Lormeau. All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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1. Redistributions of source code must retain the above copyright notice,
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this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the distribution.
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3. The names of the authors may not be used to endorse or promote products
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derived from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
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INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
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INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
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INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
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OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
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EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* This program is based on JZlib 1.0.2 ymnk, JCraft,Inc.
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* JZlib is based on zlib-1.1.3, so all credit should go authors
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* Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu)
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* and contributors of zlib.
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*/
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(function(obj) {
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// Global
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var MAX_BITS = 15;
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var D_CODES = 30;
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var BL_CODES = 19;
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var LENGTH_CODES = 29;
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var LITERALS = 256;
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var L_CODES = (LITERALS + 1 + LENGTH_CODES);
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var HEAP_SIZE = (2 * L_CODES + 1);
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var END_BLOCK = 256;
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// Bit length codes must not exceed MAX_BL_BITS bits
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var MAX_BL_BITS = 7;
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// repeat previous bit length 3-6 times (2 bits of repeat count)
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var REP_3_6 = 16;
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// repeat a zero length 3-10 times (3 bits of repeat count)
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var REPZ_3_10 = 17;
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// repeat a zero length 11-138 times (7 bits of repeat count)
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var REPZ_11_138 = 18;
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// The lengths of the bit length codes are sent in order of decreasing
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// probability, to avoid transmitting the lengths for unused bit
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// length codes.
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var Buf_size = 8 * 2;
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// JZlib version : "1.0.2"
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var Z_DEFAULT_COMPRESSION = -1;
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// compression strategy
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var Z_FILTERED = 1;
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var Z_HUFFMAN_ONLY = 2;
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var Z_DEFAULT_STRATEGY = 0;
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var Z_NO_FLUSH = 0;
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var Z_PARTIAL_FLUSH = 1;
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var Z_FULL_FLUSH = 3;
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var Z_FINISH = 4;
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var Z_OK = 0;
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var Z_STREAM_END = 1;
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var Z_NEED_DICT = 2;
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var Z_STREAM_ERROR = -2;
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var Z_DATA_ERROR = -3;
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var Z_BUF_ERROR = -5;
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// Tree
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// see definition of array dist_code below
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var _dist_code = [ 0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
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10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
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12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
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13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
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14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
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14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
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15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 0, 0, 16, 17, 18, 18, 19, 19,
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20, 20, 20, 20, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
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24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
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26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
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27, 27, 27, 27, 27, 27, 27, 27, 27, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
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28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 29,
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29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
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29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29 ];
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function Tree() {
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var that = this;
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// dyn_tree; // the dynamic tree
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// max_code; // largest code with non zero frequency
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// stat_desc; // the corresponding static tree
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// Compute the optimal bit lengths for a tree and update the total bit
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// length
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// for the current block.
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// IN assertion: the fields freq and dad are set, heap[heap_max] and
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// above are the tree nodes sorted by increasing frequency.
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// OUT assertions: the field len is set to the optimal bit length, the
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// array bl_count contains the frequencies for each bit length.
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// The length opt_len is updated; static_len is also updated if stree is
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// not null.
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function gen_bitlen(s) {
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var tree = that.dyn_tree;
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var stree = that.stat_desc.static_tree;
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var extra = that.stat_desc.extra_bits;
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var base = that.stat_desc.extra_base;
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var max_length = that.stat_desc.max_length;
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var h; // heap index
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var n, m; // iterate over the tree elements
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var bits; // bit length
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var xbits; // extra bits
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var f; // frequency
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var overflow = 0; // number of elements with bit length too large
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for (bits = 0; bits <= MAX_BITS; bits++)
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s.bl_count[bits] = 0;
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// In a first pass, compute the optimal bit lengths (which may
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// overflow in the case of the bit length tree).
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tree[s.heap[s.heap_max] * 2 + 1] = 0; // root of the heap
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for (h = s.heap_max + 1; h < HEAP_SIZE; h++) {
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n = s.heap[h];
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bits = tree[tree[n * 2 + 1] * 2 + 1] + 1;
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if (bits > max_length) {
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bits = max_length;
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overflow++;
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}
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tree[n * 2 + 1] = bits;
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// We overwrite tree[n*2+1] which is no longer needed
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if (n > that.max_code)
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continue; // not a leaf node
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s.bl_count[bits]++;
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xbits = 0;
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if (n >= base)
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xbits = extra[n - base];
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f = tree[n * 2];
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s.opt_len += f * (bits + xbits);
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if (stree)
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s.static_len += f * (stree[n * 2 + 1] + xbits);
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}
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if (overflow === 0)
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return;
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// This happens for example on obj2 and pic of the Calgary corpus
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// Find the first bit length which could increase:
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do {
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bits = max_length - 1;
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while (s.bl_count[bits] === 0)
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bits--;
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s.bl_count[bits]--; // move one leaf down the tree
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s.bl_count[bits + 1] += 2; // move one overflow item as its brother
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s.bl_count[max_length]--;
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// The brother of the overflow item also moves one step up,
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// but this does not affect bl_count[max_length]
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overflow -= 2;
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} while (overflow > 0);
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for (bits = max_length; bits !== 0; bits--) {
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n = s.bl_count[bits];
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while (n !== 0) {
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m = s.heap[--h];
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if (m > that.max_code)
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continue;
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if (tree[m * 2 + 1] != bits) {
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s.opt_len += (bits - tree[m * 2 + 1]) * tree[m * 2];
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tree[m * 2 + 1] = bits;
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}
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n--;
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}
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}
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}
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// Reverse the first len bits of a code, using straightforward code (a
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// faster
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// method would use a table)
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// IN assertion: 1 <= len <= 15
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function bi_reverse(code, // the value to invert
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len // its bit length
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) {
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var res = 0;
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do {
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res |= code & 1;
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code >>>= 1;
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res <<= 1;
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} while (--len > 0);
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return res >>> 1;
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}
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// Generate the codes for a given tree and bit counts (which need not be
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// optimal).
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// IN assertion: the array bl_count contains the bit length statistics for
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// the given tree and the field len is set for all tree elements.
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// OUT assertion: the field code is set for all tree elements of non
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// zero code length.
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function gen_codes(tree, // the tree to decorate
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max_code, // largest code with non zero frequency
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bl_count // number of codes at each bit length
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) {
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var next_code = []; // next code value for each
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// bit length
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var code = 0; // running code value
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var bits; // bit index
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var n; // code index
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var len;
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// The distribution counts are first used to generate the code values
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// without bit reversal.
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for (bits = 1; bits <= MAX_BITS; bits++) {
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next_code[bits] = code = ((code + bl_count[bits - 1]) << 1);
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}
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// Check that the bit counts in bl_count are consistent. The last code
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// must be all ones.
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// Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
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// "inconsistent bit counts");
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// Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
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for (n = 0; n <= max_code; n++) {
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len = tree[n * 2 + 1];
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if (len === 0)
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continue;
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// Now reverse the bits
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tree[n * 2] = bi_reverse(next_code[len]++, len);
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}
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}
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// Construct one Huffman tree and assigns the code bit strings and lengths.
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// Update the total bit length for the current block.
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// IN assertion: the field freq is set for all tree elements.
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// OUT assertions: the fields len and code are set to the optimal bit length
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// and corresponding code. The length opt_len is updated; static_len is
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// also updated if stree is not null. The field max_code is set.
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that.build_tree = function(s) {
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var tree = that.dyn_tree;
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var stree = that.stat_desc.static_tree;
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var elems = that.stat_desc.elems;
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var n, m; // iterate over heap elements
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var max_code = -1; // largest code with non zero frequency
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var node; // new node being created
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// Construct the initial heap, with least frequent element in
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// heap[1]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
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// heap[0] is not used.
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s.heap_len = 0;
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s.heap_max = HEAP_SIZE;
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for (n = 0; n < elems; n++) {
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if (tree[n * 2] !== 0) {
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s.heap[++s.heap_len] = max_code = n;
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s.depth[n] = 0;
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} else {
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tree[n * 2 + 1] = 0;
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}
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}
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// The pkzip format requires that at least one distance code exists,
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// and that at least one bit should be sent even if there is only one
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// possible code. So to avoid special checks later on we force at least
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// two codes of non zero frequency.
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while (s.heap_len < 2) {
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node = s.heap[++s.heap_len] = max_code < 2 ? ++max_code : 0;
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tree[node * 2] = 1;
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s.depth[node] = 0;
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s.opt_len--;
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if (stree)
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s.static_len -= stree[node * 2 + 1];
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// node is 0 or 1 so it does not have extra bits
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}
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that.max_code = max_code;
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// The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
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// establish sub-heaps of increasing lengths:
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for (n = Math.floor(s.heap_len / 2); n >= 1; n--)
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s.pqdownheap(tree, n);
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// Construct the Huffman tree by repeatedly combining the least two
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// frequent nodes.
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node = elems; // next internal node of the tree
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do {
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// n = node of least frequency
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n = s.heap[1];
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s.heap[1] = s.heap[s.heap_len--];
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s.pqdownheap(tree, 1);
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m = s.heap[1]; // m = node of next least frequency
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s.heap[--s.heap_max] = n; // keep the nodes sorted by frequency
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s.heap[--s.heap_max] = m;
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// Create a new node father of n and m
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tree[node * 2] = (tree[n * 2] + tree[m * 2]);
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s.depth[node] = Math.max(s.depth[n], s.depth[m]) + 1;
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tree[n * 2 + 1] = tree[m * 2 + 1] = node;
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// and insert the new node in the heap
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s.heap[1] = node++;
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s.pqdownheap(tree, 1);
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} while (s.heap_len >= 2);
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s.heap[--s.heap_max] = s.heap[1];
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// At this point, the fields freq and dad are set. We can now
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// generate the bit lengths.
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gen_bitlen(s);
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// The field len is now set, we can generate the bit codes
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gen_codes(tree, that.max_code, s.bl_count);
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};
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}
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Tree._length_code = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16,
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16, 16, 16, 16, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 20,
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20, 20, 20, 20, 20, 20, 20, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
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22, 22, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
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24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
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25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
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26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 28 ];
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Tree.base_length = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 0 ];
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Tree.base_dist = [ 0, 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192, 256, 384, 512, 768, 1024, 1536, 2048, 3072, 4096, 6144, 8192, 12288, 16384,
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24576 ];
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// Mapping from a distance to a distance code. dist is the distance - 1 and
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// must not have side effects. _dist_code[256] and _dist_code[257] are never
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// used.
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Tree.d_code = function(dist) {
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return ((dist) < 256 ? _dist_code[dist] : _dist_code[256 + ((dist) >>> 7)]);
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};
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// extra bits for each length code
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Tree.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 ];
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// extra bits for each distance code
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Tree.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 ];
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// extra bits for each bit length code
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Tree.extra_blbits = [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 ];
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Tree.bl_order = [ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 ];
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// StaticTree
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function StaticTree(static_tree, extra_bits, extra_base, elems, max_length) {
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var that = this;
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that.static_tree = static_tree;
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that.extra_bits = extra_bits;
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that.extra_base = extra_base;
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that.elems = elems;
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that.max_length = max_length;
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}
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StaticTree.static_ltree = [ 12, 8, 140, 8, 76, 8, 204, 8, 44, 8, 172, 8, 108, 8, 236, 8, 28, 8, 156, 8, 92, 8, 220, 8, 60, 8, 188, 8, 124, 8, 252, 8, 2, 8,
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130, 8, 66, 8, 194, 8, 34, 8, 162, 8, 98, 8, 226, 8, 18, 8, 146, 8, 82, 8, 210, 8, 50, 8, 178, 8, 114, 8, 242, 8, 10, 8, 138, 8, 74, 8, 202, 8, 42,
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8, 170, 8, 106, 8, 234, 8, 26, 8, 154, 8, 90, 8, 218, 8, 58, 8, 186, 8, 122, 8, 250, 8, 6, 8, 134, 8, 70, 8, 198, 8, 38, 8, 166, 8, 102, 8, 230, 8,
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22, 8, 150, 8, 86, 8, 214, 8, 54, 8, 182, 8, 118, 8, 246, 8, 14, 8, 142, 8, 78, 8, 206, 8, 46, 8, 174, 8, 110, 8, 238, 8, 30, 8, 158, 8, 94, 8,
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222, 8, 62, 8, 190, 8, 126, 8, 254, 8, 1, 8, 129, 8, 65, 8, 193, 8, 33, 8, 161, 8, 97, 8, 225, 8, 17, 8, 145, 8, 81, 8, 209, 8, 49, 8, 177, 8, 113,
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8, 241, 8, 9, 8, 137, 8, 73, 8, 201, 8, 41, 8, 169, 8, 105, 8, 233, 8, 25, 8, 153, 8, 89, 8, 217, 8, 57, 8, 185, 8, 121, 8, 249, 8, 5, 8, 133, 8,
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69, 8, 197, 8, 37, 8, 165, 8, 101, 8, 229, 8, 21, 8, 149, 8, 85, 8, 213, 8, 53, 8, 181, 8, 117, 8, 245, 8, 13, 8, 141, 8, 77, 8, 205, 8, 45, 8,
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173, 8, 109, 8, 237, 8, 29, 8, 157, 8, 93, 8, 221, 8, 61, 8, 189, 8, 125, 8, 253, 8, 19, 9, 275, 9, 147, 9, 403, 9, 83, 9, 339, 9, 211, 9, 467, 9,
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51, 9, 307, 9, 179, 9, 435, 9, 115, 9, 371, 9, 243, 9, 499, 9, 11, 9, 267, 9, 139, 9, 395, 9, 75, 9, 331, 9, 203, 9, 459, 9, 43, 9, 299, 9, 171, 9,
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427, 9, 107, 9, 363, 9, 235, 9, 491, 9, 27, 9, 283, 9, 155, 9, 411, 9, 91, 9, 347, 9, 219, 9, 475, 9, 59, 9, 315, 9, 187, 9, 443, 9, 123, 9, 379,
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9, 251, 9, 507, 9, 7, 9, 263, 9, 135, 9, 391, 9, 71, 9, 327, 9, 199, 9, 455, 9, 39, 9, 295, 9, 167, 9, 423, 9, 103, 9, 359, 9, 231, 9, 487, 9, 23,
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9, 279, 9, 151, 9, 407, 9, 87, 9, 343, 9, 215, 9, 471, 9, 55, 9, 311, 9, 183, 9, 439, 9, 119, 9, 375, 9, 247, 9, 503, 9, 15, 9, 271, 9, 143, 9,
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399, 9, 79, 9, 335, 9, 207, 9, 463, 9, 47, 9, 303, 9, 175, 9, 431, 9, 111, 9, 367, 9, 239, 9, 495, 9, 31, 9, 287, 9, 159, 9, 415, 9, 95, 9, 351, 9,
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223, 9, 479, 9, 63, 9, 319, 9, 191, 9, 447, 9, 127, 9, 383, 9, 255, 9, 511, 9, 0, 7, 64, 7, 32, 7, 96, 7, 16, 7, 80, 7, 48, 7, 112, 7, 8, 7, 72, 7,
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40, 7, 104, 7, 24, 7, 88, 7, 56, 7, 120, 7, 4, 7, 68, 7, 36, 7, 100, 7, 20, 7, 84, 7, 52, 7, 116, 7, 3, 8, 131, 8, 67, 8, 195, 8, 35, 8, 163, 8,
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99, 8, 227, 8 ];
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StaticTree.static_dtree = [ 0, 5, 16, 5, 8, 5, 24, 5, 4, 5, 20, 5, 12, 5, 28, 5, 2, 5, 18, 5, 10, 5, 26, 5, 6, 5, 22, 5, 14, 5, 30, 5, 1, 5, 17, 5, 9, 5,
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25, 5, 5, 5, 21, 5, 13, 5, 29, 5, 3, 5, 19, 5, 11, 5, 27, 5, 7, 5, 23, 5 ];
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StaticTree.static_l_desc = new StaticTree(StaticTree.static_ltree, Tree.extra_lbits, LITERALS + 1, L_CODES, MAX_BITS);
|
|
StaticTree.static_d_desc = new StaticTree(StaticTree.static_dtree, Tree.extra_dbits, 0, D_CODES, MAX_BITS);
|
|
StaticTree.static_bl_desc = new StaticTree(null, Tree.extra_blbits, 0, BL_CODES, MAX_BL_BITS);
|
|
// Deflate
|
|
var MAX_MEM_LEVEL = 9;
|
var DEF_MEM_LEVEL = 8;
|
|
function Config(good_length, max_lazy, nice_length, max_chain, func) {
|
var that = this;
|
that.good_length = good_length;
|
that.max_lazy = max_lazy;
|
that.nice_length = nice_length;
|
that.max_chain = max_chain;
|
that.func = func;
|
}
|
|
var STORED = 0;
|
var FAST = 1;
|
var SLOW = 2;
|
var config_table = [ new Config(0, 0, 0, 0, STORED), new Config(4, 4, 8, 4, FAST), new Config(4, 5, 16, 8, FAST), new Config(4, 6, 32, 32, FAST),
|
new Config(4, 4, 16, 16, SLOW), new Config(8, 16, 32, 32, SLOW), new Config(8, 16, 128, 128, SLOW), new Config(8, 32, 128, 256, SLOW),
|
new Config(32, 128, 258, 1024, SLOW), new Config(32, 258, 258, 4096, SLOW) ];
|
|
var z_errmsg = [ "need dictionary", // Z_NEED_DICT
|
// 2
|
"stream end", // Z_STREAM_END 1
|
"", // Z_OK 0
|
"", // Z_ERRNO (-1)
|
"stream error", // Z_STREAM_ERROR (-2)
|
"data error", // Z_DATA_ERROR (-3)
|
"", // Z_MEM_ERROR (-4)
|
"buffer error", // Z_BUF_ERROR (-5)
|
"",// Z_VERSION_ERROR (-6)
|
"" ];
|
|
// block not completed, need more input or more output
|
var NeedMore = 0;
|
|
// block flush performed
|
var BlockDone = 1;
|
|
// finish started, need only more output at next deflate
|
var FinishStarted = 2;
|
|
// finish done, accept no more input or output
|
var FinishDone = 3;
|
|
// preset dictionary flag in zlib header
|
var PRESET_DICT = 0x20;
|
|
var INIT_STATE = 42;
|
var BUSY_STATE = 113;
|
var FINISH_STATE = 666;
|
|
// The deflate compression method
|
var Z_DEFLATED = 8;
|
|
var STORED_BLOCK = 0;
|
var STATIC_TREES = 1;
|
var DYN_TREES = 2;
|
|
var MIN_MATCH = 3;
|
var MAX_MATCH = 258;
|
var MIN_LOOKAHEAD = (MAX_MATCH + MIN_MATCH + 1);
|
|
function smaller(tree, n, m, depth) {
|
var tn2 = tree[n * 2];
|
var tm2 = tree[m * 2];
|
return (tn2 < tm2 || (tn2 == tm2 && depth[n] <= depth[m]));
|
}
|
|
function Deflate() {
|
|
var that = this;
|
var strm; // pointer back to this zlib stream
|
var status; // as the name implies
|
// pending_buf; // output still pending
|
var pending_buf_size; // size of pending_buf
|
// pending_out; // next pending byte to output to the stream
|
// pending; // nb of bytes in the pending buffer
|
var method; // STORED (for zip only) or DEFLATED
|
var last_flush; // value of flush param for previous deflate call
|
|
var w_size; // LZ77 window size (32K by default)
|
var w_bits; // log2(w_size) (8..16)
|
var w_mask; // w_size - 1
|
|
var window;
|
// Sliding window. Input bytes are read into the second half of the window,
|
// and move to the first half later to keep a dictionary of at least wSize
|
// bytes. With this organization, matches are limited to a distance of
|
// wSize-MAX_MATCH bytes, but this ensures that IO is always
|
// performed with a length multiple of the block size. Also, it limits
|
// the window size to 64K, which is quite useful on MSDOS.
|
// To do: use the user input buffer as sliding window.
|
|
var window_size;
|
// Actual size of window: 2*wSize, except when the user input buffer
|
// is directly used as sliding window.
|
|
var prev;
|
// Link to older string with same hash index. To limit the size of this
|
// array to 64K, this link is maintained only for the last 32K strings.
|
// An index in this array is thus a window index modulo 32K.
|
|
var head; // Heads of the hash chains or NIL.
|
|
var ins_h; // hash index of string to be inserted
|
var hash_size; // number of elements in hash table
|
var hash_bits; // log2(hash_size)
|
var hash_mask; // hash_size-1
|
|
// Number of bits by which ins_h must be shifted at each input
|
// step. It must be such that after MIN_MATCH steps, the oldest
|
// byte no longer takes part in the hash key, that is:
|
// hash_shift * MIN_MATCH >= hash_bits
|
var hash_shift;
|
|
// Window position at the beginning of the current output block. Gets
|
// negative when the window is moved backwards.
|
|
var block_start;
|
|
var match_length; // length of best match
|
var prev_match; // previous match
|
var match_available; // set if previous match exists
|
var strstart; // start of string to insert
|
var match_start; // start of matching string
|
var lookahead; // number of valid bytes ahead in window
|
|
// Length of the best match at previous step. Matches not greater than this
|
// are discarded. This is used in the lazy match evaluation.
|
var prev_length;
|
|
// To speed up deflation, hash chains are never searched beyond this
|
// length. A higher limit improves compression ratio but degrades the speed.
|
var max_chain_length;
|
|
// Attempt to find a better match only when the current match is strictly
|
// smaller than this value. This mechanism is used only for compression
|
// levels >= 4.
|
var max_lazy_match;
|
|
// Insert new strings in the hash table only if the match length is not
|
// greater than this length. This saves time but degrades compression.
|
// max_insert_length is used only for compression levels <= 3.
|
|
var level; // compression level (1..9)
|
var strategy; // favor or force Huffman coding
|
|
// Use a faster search when the previous match is longer than this
|
var good_match;
|
|
// Stop searching when current match exceeds this
|
var nice_match;
|
|
var dyn_ltree; // literal and length tree
|
var dyn_dtree; // distance tree
|
var bl_tree; // Huffman tree for bit lengths
|
|
var l_desc = new Tree(); // desc for literal tree
|
var d_desc = new Tree(); // desc for distance tree
|
var bl_desc = new Tree(); // desc for bit length tree
|
|
// that.heap_len; // number of elements in the heap
|
// that.heap_max; // element of largest frequency
|
// The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
|
// The same heap array is used to build all trees.
|
|
// Depth of each subtree used as tie breaker for trees of equal frequency
|
that.depth = [];
|
|
var l_buf; // index for literals or lengths */
|
|
// Size of match buffer for literals/lengths. There are 4 reasons for
|
// limiting lit_bufsize to 64K:
|
// - frequencies can be kept in 16 bit counters
|
// - if compression is not successful for the first block, all input
|
// data is still in the window so we can still emit a stored block even
|
// when input comes from standard input. (This can also be done for
|
// all blocks if lit_bufsize is not greater than 32K.)
|
// - if compression is not successful for a file smaller than 64K, we can
|
// even emit a stored file instead of a stored block (saving 5 bytes).
|
// This is applicable only for zip (not gzip or zlib).
|
// - creating new Huffman trees less frequently may not provide fast
|
// adaptation to changes in the input data statistics. (Take for
|
// example a binary file with poorly compressible code followed by
|
// a highly compressible string table.) Smaller buffer sizes give
|
// fast adaptation but have of course the overhead of transmitting
|
// trees more frequently.
|
// - I can't count above 4
|
var lit_bufsize;
|
|
var last_lit; // running index in l_buf
|
|
// Buffer for distances. To simplify the code, d_buf and l_buf have
|
// the same number of elements. To use different lengths, an extra flag
|
// array would be necessary.
|
|
var d_buf; // index of pendig_buf
|
|
// that.opt_len; // bit length of current block with optimal trees
|
// that.static_len; // bit length of current block with static trees
|
var matches; // number of string matches in current block
|
var last_eob_len; // bit length of EOB code for last block
|
|
// Output buffer. bits are inserted starting at the bottom (least
|
// significant bits).
|
var bi_buf;
|
|
// Number of valid bits in bi_buf. All bits above the last valid bit
|
// are always zero.
|
var bi_valid;
|
|
// number of codes at each bit length for an optimal tree
|
that.bl_count = [];
|
|
// heap used to build the Huffman trees
|
that.heap = [];
|
|
dyn_ltree = [];
|
dyn_dtree = [];
|
bl_tree = [];
|
|
function lm_init() {
|
var i;
|
window_size = 2 * w_size;
|
|
head[hash_size - 1] = 0;
|
for (i = 0; i < hash_size - 1; i++) {
|
head[i] = 0;
|
}
|
|
// Set the default configuration parameters:
|
max_lazy_match = config_table[level].max_lazy;
|
good_match = config_table[level].good_length;
|
nice_match = config_table[level].nice_length;
|
max_chain_length = config_table[level].max_chain;
|
|
strstart = 0;
|
block_start = 0;
|
lookahead = 0;
|
match_length = prev_length = MIN_MATCH - 1;
|
match_available = 0;
|
ins_h = 0;
|
}
|
|
function init_block() {
|
var i;
|
// Initialize the trees.
|
for (i = 0; i < L_CODES; i++)
|
dyn_ltree[i * 2] = 0;
|
for (i = 0; i < D_CODES; i++)
|
dyn_dtree[i * 2] = 0;
|
for (i = 0; i < BL_CODES; i++)
|
bl_tree[i * 2] = 0;
|
|
dyn_ltree[END_BLOCK * 2] = 1;
|
that.opt_len = that.static_len = 0;
|
last_lit = matches = 0;
|
}
|
|
// Initialize the tree data structures for a new zlib stream.
|
function tr_init() {
|
|
l_desc.dyn_tree = dyn_ltree;
|
l_desc.stat_desc = StaticTree.static_l_desc;
|
|
d_desc.dyn_tree = dyn_dtree;
|
d_desc.stat_desc = StaticTree.static_d_desc;
|
|
bl_desc.dyn_tree = bl_tree;
|
bl_desc.stat_desc = StaticTree.static_bl_desc;
|
|
bi_buf = 0;
|
bi_valid = 0;
|
last_eob_len = 8; // enough lookahead for inflate
|
|
// Initialize the first block of the first file:
|
init_block();
|
}
|
|
// 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).
|
that.pqdownheap = function(tree, // the tree to restore
|
k // node to move down
|
) {
|
var heap = that.heap;
|
var v = heap[k];
|
var j = k << 1; // left son of k
|
while (j <= that.heap_len) {
|
// Set j to the smallest of the two sons:
|
if (j < that.heap_len && smaller(tree, heap[j + 1], heap[j], that.depth)) {
|
j++;
|
}
|
// Exit if v is smaller than both sons
|
if (smaller(tree, v, heap[j], that.depth))
|
break;
|
|
// Exchange v with the smallest son
|
heap[k] = heap[j];
|
k = j;
|
// And continue down the tree, setting j to the left son of k
|
j <<= 1;
|
}
|
heap[k] = v;
|
};
|
|
// Scan a literal or distance tree to determine the frequencies of the codes
|
// in the bit length tree.
|
function scan_tree(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 * 2 + 1]; // 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) * 2 + 1] = 0xffff; // guard
|
|
for (n = 0; n <= max_code; n++) {
|
curlen = nextlen;
|
nextlen = tree[(n + 1) * 2 + 1];
|
if (++count < max_count && curlen == nextlen) {
|
continue;
|
} else if (count < min_count) {
|
bl_tree[curlen * 2] += count;
|
} else if (curlen !== 0) {
|
if (curlen != prevlen)
|
bl_tree[curlen * 2]++;
|
bl_tree[REP_3_6 * 2]++;
|
} else if (count <= 10) {
|
bl_tree[REPZ_3_10 * 2]++;
|
} else {
|
bl_tree[REPZ_11_138 * 2]++;
|
}
|
count = 0;
|
prevlen = curlen;
|
if (nextlen === 0) {
|
max_count = 138;
|
min_count = 3;
|
} else if (curlen == nextlen) {
|
max_count = 6;
|
min_count = 3;
|
} else {
|
max_count = 7;
|
min_count = 4;
|
}
|
}
|
}
|
|
// Construct the Huffman tree for the bit lengths and return the index in
|
// bl_order of the last bit length code to send.
|
function build_bl_tree() {
|
var max_blindex; // index of last bit length code of non zero freq
|
|
// Determine the bit length frequencies for literal and distance trees
|
scan_tree(dyn_ltree, l_desc.max_code);
|
scan_tree(dyn_dtree, d_desc.max_code);
|
|
// Build the bit length tree:
|
bl_desc.build_tree(that);
|
// opt_len now includes the length of the tree representations, except
|
// the lengths of the bit lengths codes and the 5+5+4 bits for the
|
// counts.
|
|
// Determine the number of bit length codes to send. The pkzip format
|
// requires that at least 4 bit length codes be sent. (appnote.txt says
|
// 3 but the actual value used is 4.)
|
for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--) {
|
if (bl_tree[Tree.bl_order[max_blindex] * 2 + 1] !== 0)
|
break;
|
}
|
// Update opt_len to include the bit length tree and counts
|
that.opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
|
|
return max_blindex;
|
}
|
|
// Output a byte on the stream.
|
// IN assertion: there is enough room in pending_buf.
|
function put_byte(p) {
|
that.pending_buf[that.pending++] = p;
|
}
|
|
function put_short(w) {
|
put_byte(w & 0xff);
|
put_byte((w >>> 8) & 0xff);
|
}
|
|
function putShortMSB(b) {
|
put_byte((b >> 8) & 0xff);
|
put_byte((b & 0xff) & 0xff);
|
}
|
|
function send_bits(value, length) {
|
var val, len = length;
|
if (bi_valid > Buf_size - len) {
|
val = value;
|
// bi_buf |= (val << bi_valid);
|
bi_buf |= ((val << bi_valid) & 0xffff);
|
put_short(bi_buf);
|
bi_buf = val >>> (Buf_size - bi_valid);
|
bi_valid += len - Buf_size;
|
} else {
|
// bi_buf |= (value) << bi_valid;
|
bi_buf |= (((value) << bi_valid) & 0xffff);
|
bi_valid += len;
|
}
|
}
|
|
function send_code(c, tree) {
|
var c2 = c * 2;
|
send_bits(tree[c2] & 0xffff, tree[c2 + 1] & 0xffff);
|
}
|
|
// Send a literal or distance tree in compressed form, using the codes in
|
// bl_tree.
|
function send_tree(tree,// the tree to be sent
|
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 * 2 + 1]; // 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;
|
}
|
|
for (n = 0; n <= max_code; n++) {
|
curlen = nextlen;
|
nextlen = tree[(n + 1) * 2 + 1];
|
if (++count < max_count && curlen == nextlen) {
|
continue;
|
} else if (count < min_count) {
|
do {
|
send_code(curlen, bl_tree);
|
} while (--count !== 0);
|
} else if (curlen !== 0) {
|
if (curlen != prevlen) {
|
send_code(curlen, bl_tree);
|
count--;
|
}
|
send_code(REP_3_6, bl_tree);
|
send_bits(count - 3, 2);
|
} else if (count <= 10) {
|
send_code(REPZ_3_10, bl_tree);
|
send_bits(count - 3, 3);
|
} else {
|
send_code(REPZ_11_138, bl_tree);
|
send_bits(count - 11, 7);
|
}
|
count = 0;
|
prevlen = curlen;
|
if (nextlen === 0) {
|
max_count = 138;
|
min_count = 3;
|
} else if (curlen == nextlen) {
|
max_count = 6;
|
min_count = 3;
|
} else {
|
max_count = 7;
|
min_count = 4;
|
}
|
}
|
}
|
|
// 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.
|
function send_all_trees(lcodes, dcodes, blcodes) {
|
var rank; // index in bl_order
|
|
send_bits(lcodes - 257, 5); // not +255 as stated in appnote.txt
|
send_bits(dcodes - 1, 5);
|
send_bits(blcodes - 4, 4); // not -3 as stated in appnote.txt
|
for (rank = 0; rank < blcodes; rank++) {
|
send_bits(bl_tree[Tree.bl_order[rank] * 2 + 1], 3);
|
}
|
send_tree(dyn_ltree, lcodes - 1); // literal tree
|
send_tree(dyn_dtree, dcodes - 1); // distance tree
|
}
|
|
// Flush the bit buffer, keeping at most 7 bits in it.
|
function bi_flush() {
|
if (bi_valid == 16) {
|
put_short(bi_buf);
|
bi_buf = 0;
|
bi_valid = 0;
|
} else if (bi_valid >= 8) {
|
put_byte(bi_buf & 0xff);
|
bi_buf >>>= 8;
|
bi_valid -= 8;
|
}
|
}
|
|
// Send one empty static block to give enough lookahead for inflate.
|
// This takes 10 bits, of which 7 may remain in the bit buffer.
|
// The current inflate code requires 9 bits of lookahead. If the
|
// last two codes for the previous block (real code plus EOB) were coded
|
// on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
|
// the last real code. In this case we send two empty static blocks instead
|
// of one. (There are no problems if the previous block is stored or fixed.)
|
// To simplify the code, we assume the worst case of last real code encoded
|
// on one bit only.
|
function _tr_align() {
|
send_bits(STATIC_TREES << 1, 3);
|
send_code(END_BLOCK, StaticTree.static_ltree);
|
|
bi_flush();
|
|
// Of the 10 bits for the empty block, we have already sent
|
// (10 - bi_valid) bits. The lookahead for the last real code (before
|
// the EOB of the previous block) was thus at least one plus the length
|
// of the EOB plus what we have just sent of the empty static block.
|
if (1 + last_eob_len + 10 - bi_valid < 9) {
|
send_bits(STATIC_TREES << 1, 3);
|
send_code(END_BLOCK, StaticTree.static_ltree);
|
bi_flush();
|
}
|
last_eob_len = 7;
|
}
|
|
// Save the match info and tally the frequency counts. Return true if
|
// the current block must be flushed.
|
function _tr_tally(dist, // distance of matched string
|
lc // match length-MIN_MATCH or unmatched char (if dist==0)
|
) {
|
var out_length, in_length, dcode;
|
that.pending_buf[d_buf + last_lit * 2] = (dist >>> 8) & 0xff;
|
that.pending_buf[d_buf + last_lit * 2 + 1] = dist & 0xff;
|
|
that.pending_buf[l_buf + last_lit] = lc & 0xff;
|
last_lit++;
|
|
if (dist === 0) {
|
// lc is the unmatched char
|
dyn_ltree[lc * 2]++;
|
} else {
|
matches++;
|
// Here, lc is the match length - MIN_MATCH
|
dist--; // dist = match distance - 1
|
dyn_ltree[(Tree._length_code[lc] + LITERALS + 1) * 2]++;
|
dyn_dtree[Tree.d_code(dist) * 2]++;
|
}
|
|
if ((last_lit & 0x1fff) === 0 && level > 2) {
|
// Compute an upper bound for the compressed length
|
out_length = last_lit * 8;
|
in_length = strstart - block_start;
|
for (dcode = 0; dcode < D_CODES; dcode++) {
|
out_length += dyn_dtree[dcode * 2] * (5 + Tree.extra_dbits[dcode]);
|
}
|
out_length >>>= 3;
|
if ((matches < Math.floor(last_lit / 2)) && out_length < Math.floor(in_length / 2))
|
return true;
|
}
|
|
return (last_lit == lit_bufsize - 1);
|
// We avoid equality with lit_bufsize because of wraparound at 64K
|
// on 16 bit machines and because stored blocks are restricted to
|
// 64K-1 bytes.
|
}
|
|
// Send the block data compressed using the given Huffman trees
|
function compress_block(ltree, dtree) {
|
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 code; // the code to send
|
var extra; // number of extra bits to send
|
|
if (last_lit !== 0) {
|
do {
|
dist = ((that.pending_buf[d_buf + lx * 2] << 8) & 0xff00) | (that.pending_buf[d_buf + lx * 2 + 1] & 0xff);
|
lc = (that.pending_buf[l_buf + lx]) & 0xff;
|
lx++;
|
|
if (dist === 0) {
|
send_code(lc, ltree); // send a literal byte
|
} else {
|
// Here, lc is the match length - MIN_MATCH
|
code = Tree._length_code[lc];
|
|
send_code(code + LITERALS + 1, ltree); // send the length
|
// code
|
extra = Tree.extra_lbits[code];
|
if (extra !== 0) {
|
lc -= Tree.base_length[code];
|
send_bits(lc, extra); // send the extra length bits
|
}
|
dist--; // dist is now the match distance - 1
|
code = Tree.d_code(dist);
|
|
send_code(code, dtree); // send the distance code
|
extra = Tree.extra_dbits[code];
|
if (extra !== 0) {
|
dist -= Tree.base_dist[code];
|
send_bits(dist, extra); // send the extra distance bits
|
}
|
} // literal or match pair ?
|
|
// Check that the overlay between pending_buf and d_buf+l_buf is
|
// ok:
|
} while (lx < last_lit);
|
}
|
|
send_code(END_BLOCK, ltree);
|
last_eob_len = ltree[END_BLOCK * 2 + 1];
|
}
|
|
// Flush the bit buffer and align the output on a byte boundary
|
function bi_windup() {
|
if (bi_valid > 8) {
|
put_short(bi_buf);
|
} else if (bi_valid > 0) {
|
put_byte(bi_buf & 0xff);
|
}
|
bi_buf = 0;
|
bi_valid = 0;
|
}
|
|
// Copy a stored block, storing first the length and its
|
// one's complement if requested.
|
function copy_block(buf, // the input data
|
len, // its length
|
header // true if block header must be written
|
) {
|
bi_windup(); // align on byte boundary
|
last_eob_len = 8; // enough lookahead for inflate
|
|
if (header) {
|
put_short(len);
|
put_short(~len);
|
}
|
|
that.pending_buf.set(window.subarray(buf, buf + len), that.pending);
|
that.pending += len;
|
}
|
|
// Send a stored block
|
function _tr_stored_block(buf, // input block
|
stored_len, // length of input block
|
eof // true if this is the last block for a file
|
) {
|
send_bits((STORED_BLOCK << 1) + (eof ? 1 : 0), 3); // send block type
|
copy_block(buf, stored_len, true); // with header
|
}
|
|
// Determine the best encoding for the current block: dynamic trees, static
|
// trees or store, and output the encoded block to the zip file.
|
function _tr_flush_block(buf, // input block, or NULL if too old
|
stored_len, // length of input block
|
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 = 0; // index of last bit length code of non zero freq
|
|
// Build the Huffman trees unless a stored block is forced
|
if (level > 0) {
|
// Construct the literal and distance trees
|
l_desc.build_tree(that);
|
|
d_desc.build_tree(that);
|
|
// At this point, opt_len and static_len are the total bit lengths
|
// of
|
// the compressed block data, excluding the tree representations.
|
|
// Build the bit length tree for the above two trees, and get the
|
// index
|
// in bl_order of the last bit length code to send.
|
max_blindex = build_bl_tree();
|
|
// Determine the best encoding. Compute first the block length in
|
// bytes
|
opt_lenb = (that.opt_len + 3 + 7) >>> 3;
|
static_lenb = (that.static_len + 3 + 7) >>> 3;
|
|
if (static_lenb <= opt_lenb)
|
opt_lenb = static_lenb;
|
} else {
|
opt_lenb = static_lenb = stored_len + 5; // force a stored block
|
}
|
|
if ((stored_len + 4 <= opt_lenb) && buf != -1) {
|
// 4: two words for the lengths
|
// The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
|
// Otherwise we can't have processed more than WSIZE input bytes
|
// since
|
// the last block flush, because compression would have been
|
// successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
|
// transform a block into a stored block.
|
_tr_stored_block(buf, stored_len, eof);
|
} else if (static_lenb == opt_lenb) {
|
send_bits((STATIC_TREES << 1) + (eof ? 1 : 0), 3);
|
compress_block(StaticTree.static_ltree, StaticTree.static_dtree);
|
} else {
|
send_bits((DYN_TREES << 1) + (eof ? 1 : 0), 3);
|
send_all_trees(l_desc.max_code + 1, d_desc.max_code + 1, max_blindex + 1);
|
compress_block(dyn_ltree, dyn_dtree);
|
}
|
|
// The above check is made mod 2^32, for files larger than 512 MB
|
// and uLong implemented on 32 bits.
|
|
init_block();
|
|
if (eof) {
|
bi_windup();
|
}
|
}
|
|
function flush_block_only(eof) {
|
_tr_flush_block(block_start >= 0 ? block_start : -1, strstart - block_start, eof);
|
block_start = strstart;
|
strm.flush_pending();
|
}
|
|
// Fill the window when the lookahead becomes insufficient.
|
// Updates strstart and lookahead.
|
//
|
// IN assertion: lookahead < MIN_LOOKAHEAD
|
// OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
|
// At least one byte has been read, or avail_in === 0; reads are
|
// performed for at least two bytes (required for the zip translate_eol
|
// option -- not supported here).
|
function fill_window() {
|
var n, m;
|
var p;
|
var more; // Amount of free space at the end of the window.
|
|
do {
|
more = (window_size - lookahead - strstart);
|
|
// Deal with !@#$% 64K limit:
|
if (more === 0 && strstart === 0 && lookahead === 0) {
|
more = w_size;
|
} else if (more == -1) {
|
// Very unlikely, but possible on 16 bit machine if strstart ==
|
// 0
|
// and lookahead == 1 (input done one byte at time)
|
more--;
|
|
// If the window is almost full and there is insufficient
|
// lookahead,
|
// move the upper half to the lower one to make room in the
|
// upper half.
|
} else if (strstart >= w_size + w_size - MIN_LOOKAHEAD) {
|
window.set(window.subarray(w_size, w_size + w_size), 0);
|
|
match_start -= w_size;
|
strstart -= w_size; // we now have strstart >= MAX_DIST
|
block_start -= w_size;
|
|
// Slide the hash table (could be avoided with 32 bit values
|
// at the expense of memory usage). We slide even when level ==
|
// 0
|
// to keep the hash table consistent if we switch back to level
|
// > 0
|
// later. (Using level 0 permanently is not an optimal usage of
|
// zlib, so we don't care about this pathological case.)
|
|
n = hash_size;
|
p = n;
|
do {
|
m = (head[--p] & 0xffff);
|
head[p] = (m >= w_size ? m - w_size : 0);
|
} while (--n !== 0);
|
|
n = w_size;
|
p = n;
|
do {
|
m = (prev[--p] & 0xffff);
|
prev[p] = (m >= w_size ? m - w_size : 0);
|
// If n is not on any hash chain, prev[n] is garbage but
|
// its value will never be used.
|
} while (--n !== 0);
|
more += w_size;
|
}
|
|
if (strm.avail_in === 0)
|
return;
|
|
// If there was no sliding:
|
// strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
|
// more == window_size - lookahead - strstart
|
// => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
|
// => more >= window_size - 2*WSIZE + 2
|
// In the BIG_MEM or MMAP case (not yet supported),
|
// window_size == input_size + MIN_LOOKAHEAD &&
|
// strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
|
// Otherwise, window_size == 2*WSIZE so more >= 2.
|
// If there was sliding, more >= WSIZE. So in all cases, more >= 2.
|
|
n = strm.read_buf(window, strstart + lookahead, more);
|
lookahead += n;
|
|
// Initialize the hash value now that we have some input:
|
if (lookahead >= MIN_MATCH) {
|
ins_h = window[strstart] & 0xff;
|
ins_h = (((ins_h) << hash_shift) ^ (window[strstart + 1] & 0xff)) & hash_mask;
|
}
|
// If the whole input has less than MIN_MATCH bytes, ins_h is
|
// garbage,
|
// but this is not important since only literal bytes will be
|
// emitted.
|
} while (lookahead < MIN_LOOKAHEAD && strm.avail_in !== 0);
|
}
|
|
// Copy without compression as much as possible from the input stream,
|
// return
|
// the current block state.
|
// This function does not insert new strings in the dictionary since
|
// uncompressible data is probably not useful. This function is used
|
// only for the level=0 compression option.
|
// NOTE: this function should be optimized to avoid extra copying from
|
// window to pending_buf.
|
function deflate_stored(flush) {
|
// Stored blocks are limited to 0xffff bytes, pending_buf is limited
|
// to pending_buf_size, and each stored block has a 5 byte header:
|
|
var max_block_size = 0xffff;
|
var max_start;
|
|
if (max_block_size > pending_buf_size - 5) {
|
max_block_size = pending_buf_size - 5;
|
}
|
|
// Copy as much as possible from input to output:
|
while (true) {
|
// Fill the window as much as possible:
|
if (lookahead <= 1) {
|
fill_window();
|
if (lookahead === 0 && flush == Z_NO_FLUSH)
|
return NeedMore;
|
if (lookahead === 0)
|
break; // flush the current block
|
}
|
|
strstart += lookahead;
|
lookahead = 0;
|
|
// Emit a stored block if pending_buf will be full:
|
max_start = block_start + max_block_size;
|
if (strstart === 0 || strstart >= max_start) {
|
// strstart === 0 is possible when wraparound on 16-bit machine
|
lookahead = (strstart - max_start);
|
strstart = max_start;
|
|
flush_block_only(false);
|
if (strm.avail_out === 0)
|
return NeedMore;
|
|
}
|
|
// Flush if we may have to slide, otherwise block_start may become
|
// negative and the data will be gone:
|
if (strstart - block_start >= w_size - MIN_LOOKAHEAD) {
|
flush_block_only(false);
|
if (strm.avail_out === 0)
|
return NeedMore;
|
}
|
}
|
|
flush_block_only(flush == Z_FINISH);
|
if (strm.avail_out === 0)
|
return (flush == Z_FINISH) ? FinishStarted : NeedMore;
|
|
return flush == Z_FINISH ? FinishDone : BlockDone;
|
}
|
|
function longest_match(cur_match) {
|
var chain_length = max_chain_length; // max hash chain length
|
var scan = strstart; // current string
|
var match; // matched string
|
var len; // length of current match
|
var best_len = prev_length; // best match length so far
|
var limit = strstart > (w_size - MIN_LOOKAHEAD) ? strstart - (w_size - MIN_LOOKAHEAD) : 0;
|
var _nice_match = nice_match;
|
|
// Stop when cur_match becomes <= limit. To simplify the code,
|
// we prevent matches with the string of window index 0.
|
|
var wmask = w_mask;
|
|
var strend = strstart + MAX_MATCH;
|
var scan_end1 = window[scan + best_len - 1];
|
var scan_end = window[scan + best_len];
|
|
// The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of
|
// 16.
|
// It is easy to get rid of this optimization if necessary.
|
|
// Do not waste too much time if we already have a good match:
|
if (prev_length >= good_match) {
|
chain_length >>= 2;
|
}
|
|
// Do not look for matches beyond the end of the input. This is
|
// necessary
|
// to make deflate deterministic.
|
if (_nice_match > lookahead)
|
_nice_match = lookahead;
|
|
do {
|
match = cur_match;
|
|
// Skip to next match if the match length cannot increase
|
// or if the match length is less than 2:
|
if (window[match + best_len] != scan_end || window[match + best_len - 1] != scan_end1 || window[match] != window[scan]
|
|| window[++match] != window[scan + 1])
|
continue;
|
|
// The check at best_len-1 can be removed because it will be made
|
// again later. (This heuristic is not always a win.)
|
// It is not necessary to compare scan[2] and match[2] since they
|
// are always equal when the other bytes match, given that
|
// the hash keys are equal and that HASH_BITS >= 8.
|
scan += 2;
|
match++;
|
|
// We check for insufficient lookahead only every 8th comparison;
|
// the 256th check will be made at strstart+258.
|
do {
|
} while (window[++scan] == window[++match] && window[++scan] == window[++match] && window[++scan] == window[++match]
|
&& window[++scan] == window[++match] && window[++scan] == window[++match] && window[++scan] == window[++match]
|
&& window[++scan] == window[++match] && window[++scan] == window[++match] && scan < strend);
|
|
len = MAX_MATCH - (strend - scan);
|
scan = strend - MAX_MATCH;
|
|
if (len > best_len) {
|
match_start = cur_match;
|
best_len = len;
|
if (len >= _nice_match)
|
break;
|
scan_end1 = window[scan + best_len - 1];
|
scan_end = window[scan + best_len];
|
}
|
|
} while ((cur_match = (prev[cur_match & wmask] & 0xffff)) > limit && --chain_length !== 0);
|
|
if (best_len <= lookahead)
|
return best_len;
|
return lookahead;
|
}
|
|
// Compress as much as possible from the input stream, return the current
|
// block state.
|
// This function does not perform lazy evaluation of matches and inserts
|
// new strings in the dictionary only for unmatched strings or for short
|
// matches. It is used only for the fast compression options.
|
function deflate_fast(flush) {
|
// short hash_head = 0; // head of the hash chain
|
var hash_head = 0; // head of the hash chain
|
var bflush; // set if current block must be flushed
|
|
while (true) {
|
// Make sure that we always have enough lookahead, except
|
// at the end of the input file. We need MAX_MATCH bytes
|
// for the next match, plus MIN_MATCH bytes to insert the
|
// string following the next match.
|
if (lookahead < MIN_LOOKAHEAD) {
|
fill_window();
|
if (lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
|
return NeedMore;
|
}
|
if (lookahead === 0)
|
break; // flush the current block
|
}
|
|
// Insert the string window[strstart .. strstart+2] in the
|
// dictionary, and set hash_head to the head of the hash chain:
|
if (lookahead >= MIN_MATCH) {
|
ins_h = (((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
|
|
// prev[strstart&w_mask]=hash_head=head[ins_h];
|
hash_head = (head[ins_h] & 0xffff);
|
prev[strstart & w_mask] = head[ins_h];
|
head[ins_h] = strstart;
|
}
|
|
// Find the longest match, discarding those <= prev_length.
|
// At this point we have always match_length < MIN_MATCH
|
|
if (hash_head !== 0 && ((strstart - hash_head) & 0xffff) <= w_size - MIN_LOOKAHEAD) {
|
// To simplify the code, we prevent matches with the string
|
// of window index 0 (in particular we have to avoid a match
|
// of the string with itself at the start of the input file).
|
if (strategy != Z_HUFFMAN_ONLY) {
|
match_length = longest_match(hash_head);
|
}
|
// longest_match() sets match_start
|
}
|
if (match_length >= MIN_MATCH) {
|
// check_match(strstart, match_start, match_length);
|
|
bflush = _tr_tally(strstart - match_start, match_length - MIN_MATCH);
|
|
lookahead -= match_length;
|
|
// Insert new strings in the hash table only if the match length
|
// is not too large. This saves time but degrades compression.
|
if (match_length <= max_lazy_match && lookahead >= MIN_MATCH) {
|
match_length--; // string at strstart already in hash table
|
do {
|
strstart++;
|
|
ins_h = ((ins_h << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
|
// prev[strstart&w_mask]=hash_head=head[ins_h];
|
hash_head = (head[ins_h] & 0xffff);
|
prev[strstart & w_mask] = head[ins_h];
|
head[ins_h] = strstart;
|
|
// strstart never exceeds WSIZE-MAX_MATCH, so there are
|
// always MIN_MATCH bytes ahead.
|
} while (--match_length !== 0);
|
strstart++;
|
} else {
|
strstart += match_length;
|
match_length = 0;
|
ins_h = window[strstart] & 0xff;
|
|
ins_h = (((ins_h) << hash_shift) ^ (window[strstart + 1] & 0xff)) & hash_mask;
|
// If lookahead < MIN_MATCH, ins_h is garbage, but it does
|
// not
|
// matter since it will be recomputed at next deflate call.
|
}
|
} else {
|
// No match, output a literal byte
|
|
bflush = _tr_tally(0, window[strstart] & 0xff);
|
lookahead--;
|
strstart++;
|
}
|
if (bflush) {
|
|
flush_block_only(false);
|
if (strm.avail_out === 0)
|
return NeedMore;
|
}
|
}
|
|
flush_block_only(flush == Z_FINISH);
|
if (strm.avail_out === 0) {
|
if (flush == Z_FINISH)
|
return FinishStarted;
|
else
|
return NeedMore;
|
}
|
return flush == Z_FINISH ? FinishDone : BlockDone;
|
}
|
|
// Same as above, but achieves better compression. We use a lazy
|
// evaluation for matches: a match is finally adopted only if there is
|
// no better match at the next window position.
|
function deflate_slow(flush) {
|
// short hash_head = 0; // head of hash chain
|
var hash_head = 0; // head of hash chain
|
var bflush; // set if current block must be flushed
|
var max_insert;
|
|
// Process the input block.
|
while (true) {
|
// Make sure that we always have enough lookahead, except
|
// at the end of the input file. We need MAX_MATCH bytes
|
// for the next match, plus MIN_MATCH bytes to insert the
|
// string following the next match.
|
|
if (lookahead < MIN_LOOKAHEAD) {
|
fill_window();
|
if (lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
|
return NeedMore;
|
}
|
if (lookahead === 0)
|
break; // flush the current block
|
}
|
|
// Insert the string window[strstart .. strstart+2] in the
|
// dictionary, and set hash_head to the head of the hash chain:
|
|
if (lookahead >= MIN_MATCH) {
|
ins_h = (((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
|
// prev[strstart&w_mask]=hash_head=head[ins_h];
|
hash_head = (head[ins_h] & 0xffff);
|
prev[strstart & w_mask] = head[ins_h];
|
head[ins_h] = strstart;
|
}
|
|
// Find the longest match, discarding those <= prev_length.
|
prev_length = match_length;
|
prev_match = match_start;
|
match_length = MIN_MATCH - 1;
|
|
if (hash_head !== 0 && prev_length < max_lazy_match && ((strstart - hash_head) & 0xffff) <= w_size - MIN_LOOKAHEAD) {
|
// To simplify the code, we prevent matches with the string
|
// of window index 0 (in particular we have to avoid a match
|
// of the string with itself at the start of the input file).
|
|
if (strategy != Z_HUFFMAN_ONLY) {
|
match_length = longest_match(hash_head);
|
}
|
// longest_match() sets match_start
|
|
if (match_length <= 5 && (strategy == Z_FILTERED || (match_length == MIN_MATCH && strstart - match_start > 4096))) {
|
|
// If prev_match is also MIN_MATCH, match_start is garbage
|
// but we will ignore the current match anyway.
|
match_length = MIN_MATCH - 1;
|
}
|
}
|
|
// If there was a match at the previous step and the current
|
// match is not better, output the previous match:
|
if (prev_length >= MIN_MATCH && match_length <= prev_length) {
|
max_insert = strstart + lookahead - MIN_MATCH;
|
// Do not insert strings in hash table beyond this.
|
|
// check_match(strstart-1, prev_match, prev_length);
|
|
bflush = _tr_tally(strstart - 1 - prev_match, prev_length - MIN_MATCH);
|
|
// Insert in hash table all strings up to the end of the match.
|
// strstart-1 and strstart are already inserted. If there is not
|
// enough lookahead, the last two strings are not inserted in
|
// the hash table.
|
lookahead -= prev_length - 1;
|
prev_length -= 2;
|
do {
|
if (++strstart <= max_insert) {
|
ins_h = (((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
|
// prev[strstart&w_mask]=hash_head=head[ins_h];
|
hash_head = (head[ins_h] & 0xffff);
|
prev[strstart & w_mask] = head[ins_h];
|
head[ins_h] = strstart;
|
}
|
} while (--prev_length !== 0);
|
match_available = 0;
|
match_length = MIN_MATCH - 1;
|
strstart++;
|
|
if (bflush) {
|
flush_block_only(false);
|
if (strm.avail_out === 0)
|
return NeedMore;
|
}
|
} else if (match_available !== 0) {
|
|
// If there was no match at the previous position, output a
|
// single literal. If there was a match but the current match
|
// is longer, truncate the previous match to a single literal.
|
|
bflush = _tr_tally(0, window[strstart - 1] & 0xff);
|
|
if (bflush) {
|
flush_block_only(false);
|
}
|
strstart++;
|
lookahead--;
|
if (strm.avail_out === 0)
|
return NeedMore;
|
} else {
|
// There is no previous match to compare with, wait for
|
// the next step to decide.
|
|
match_available = 1;
|
strstart++;
|
lookahead--;
|
}
|
}
|
|
if (match_available !== 0) {
|
bflush = _tr_tally(0, window[strstart - 1] & 0xff);
|
match_available = 0;
|
}
|
flush_block_only(flush == Z_FINISH);
|
|
if (strm.avail_out === 0) {
|
if (flush == Z_FINISH)
|
return FinishStarted;
|
else
|
return NeedMore;
|
}
|
|
return flush == Z_FINISH ? FinishDone : BlockDone;
|
}
|
|
function deflateReset(strm) {
|
strm.total_in = strm.total_out = 0;
|
strm.msg = null; //
|
|
that.pending = 0;
|
that.pending_out = 0;
|
|
status = BUSY_STATE;
|
|
last_flush = Z_NO_FLUSH;
|
|
tr_init();
|
lm_init();
|
return Z_OK;
|
}
|
|
that.deflateInit = function(strm, _level, bits, _method, memLevel, _strategy) {
|
if (!_method)
|
_method = Z_DEFLATED;
|
if (!memLevel)
|
memLevel = DEF_MEM_LEVEL;
|
if (!_strategy)
|
_strategy = Z_DEFAULT_STRATEGY;
|
|
// byte[] my_version=ZLIB_VERSION;
|
|
//
|
// if (!version || version[0] != my_version[0]
|
// || stream_size != sizeof(z_stream)) {
|
// return Z_VERSION_ERROR;
|
// }
|
|
strm.msg = null;
|
|
if (_level == Z_DEFAULT_COMPRESSION)
|
_level = 6;
|
|
if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || _method != Z_DEFLATED || bits < 9 || bits > 15 || _level < 0 || _level > 9 || _strategy < 0
|
|| _strategy > Z_HUFFMAN_ONLY) {
|
return Z_STREAM_ERROR;
|
}
|
|
strm.dstate = that;
|
|
w_bits = bits;
|
w_size = 1 << w_bits;
|
w_mask = w_size - 1;
|
|
hash_bits = memLevel + 7;
|
hash_size = 1 << hash_bits;
|
hash_mask = hash_size - 1;
|
hash_shift = Math.floor((hash_bits + MIN_MATCH - 1) / MIN_MATCH);
|
|
window = new Uint8Array(w_size * 2);
|
prev = [];
|
head = [];
|
|
lit_bufsize = 1 << (memLevel + 6); // 16K elements by default
|
|
// We overlay pending_buf and d_buf+l_buf. This works since the average
|
// output size for (length,distance) codes is <= 24 bits.
|
that.pending_buf = new Uint8Array(lit_bufsize * 4);
|
pending_buf_size = lit_bufsize * 4;
|
|
d_buf = Math.floor(lit_bufsize / 2);
|
l_buf = (1 + 2) * lit_bufsize;
|
|
level = _level;
|
|
strategy = _strategy;
|
method = _method & 0xff;
|
|
return deflateReset(strm);
|
};
|
|
that.deflateEnd = function() {
|
if (status != INIT_STATE && status != BUSY_STATE && status != FINISH_STATE) {
|
return Z_STREAM_ERROR;
|
}
|
// Deallocate in reverse order of allocations:
|
that.pending_buf = null;
|
head = null;
|
prev = null;
|
window = null;
|
// free
|
that.dstate = null;
|
return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
|
};
|
|
that.deflateParams = function(strm, _level, _strategy) {
|
var err = Z_OK;
|
|
if (_level == Z_DEFAULT_COMPRESSION) {
|
_level = 6;
|
}
|
if (_level < 0 || _level > 9 || _strategy < 0 || _strategy > Z_HUFFMAN_ONLY) {
|
return Z_STREAM_ERROR;
|
}
|
|
if (config_table[level].func != config_table[_level].func && strm.total_in !== 0) {
|
// Flush the last buffer:
|
err = strm.deflate(Z_PARTIAL_FLUSH);
|
}
|
|
if (level != _level) {
|
level = _level;
|
max_lazy_match = config_table[level].max_lazy;
|
good_match = config_table[level].good_length;
|
nice_match = config_table[level].nice_length;
|
max_chain_length = config_table[level].max_chain;
|
}
|
strategy = _strategy;
|
return err;
|
};
|
|
that.deflateSetDictionary = function(strm, dictionary, dictLength) {
|
var length = dictLength;
|
var n, index = 0;
|
|
if (!dictionary || status != INIT_STATE)
|
return Z_STREAM_ERROR;
|
|
if (length < MIN_MATCH)
|
return Z_OK;
|
if (length > w_size - MIN_LOOKAHEAD) {
|
length = w_size - MIN_LOOKAHEAD;
|
index = dictLength - length; // use the tail of the dictionary
|
}
|
window.set(dictionary.subarray(index, index + length), 0);
|
|
strstart = length;
|
block_start = length;
|
|
// Insert all strings in the hash table (except for the last two bytes).
|
// s->lookahead stays null, so s->ins_h will be recomputed at the next
|
// call of fill_window.
|
|
ins_h = window[0] & 0xff;
|
ins_h = (((ins_h) << hash_shift) ^ (window[1] & 0xff)) & hash_mask;
|
|
for (n = 0; n <= length - MIN_MATCH; n++) {
|
ins_h = (((ins_h) << hash_shift) ^ (window[(n) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
|
prev[n & w_mask] = head[ins_h];
|
head[ins_h] = n;
|
}
|
return Z_OK;
|
};
|
|
that.deflate = function(_strm, flush) {
|
var i, header, level_flags, old_flush, bstate;
|
|
if (flush > Z_FINISH || flush < 0) {
|
return Z_STREAM_ERROR;
|
}
|
|
if (!_strm.next_out || (!_strm.next_in && _strm.avail_in !== 0) || (status == FINISH_STATE && flush != Z_FINISH)) {
|
_strm.msg = z_errmsg[Z_NEED_DICT - (Z_STREAM_ERROR)];
|
return Z_STREAM_ERROR;
|
}
|
if (_strm.avail_out === 0) {
|
_strm.msg = z_errmsg[Z_NEED_DICT - (Z_BUF_ERROR)];
|
return Z_BUF_ERROR;
|
}
|
|
strm = _strm; // just in case
|
old_flush = last_flush;
|
last_flush = flush;
|
|
// Write the zlib header
|
if (status == INIT_STATE) {
|
header = (Z_DEFLATED + ((w_bits - 8) << 4)) << 8;
|
level_flags = ((level - 1) & 0xff) >> 1;
|
|
if (level_flags > 3)
|
level_flags = 3;
|
header |= (level_flags << 6);
|
if (strstart !== 0)
|
header |= PRESET_DICT;
|
header += 31 - (header % 31);
|
|
status = BUSY_STATE;
|
putShortMSB(header);
|
}
|
|
// Flush as much pending output as possible
|
if (that.pending !== 0) {
|
strm.flush_pending();
|
if (strm.avail_out === 0) {
|
// console.log(" avail_out==0");
|
// Since avail_out is 0, deflate will be called again with
|
// more output space, but possibly with both pending and
|
// avail_in equal to zero. There won't be anything to do,
|
// but this is not an error situation so make sure we
|
// return OK instead of BUF_ERROR at next call of deflate:
|
last_flush = -1;
|
return Z_OK;
|
}
|
|
// Make sure there is something to do and avoid duplicate
|
// consecutive
|
// flushes. For repeated and useless calls with Z_FINISH, we keep
|
// returning Z_STREAM_END instead of Z_BUFF_ERROR.
|
} else if (strm.avail_in === 0 && flush <= old_flush && flush != Z_FINISH) {
|
strm.msg = z_errmsg[Z_NEED_DICT - (Z_BUF_ERROR)];
|
return Z_BUF_ERROR;
|
}
|
|
// User must not provide more input after the first FINISH:
|
if (status == FINISH_STATE && strm.avail_in !== 0) {
|
_strm.msg = z_errmsg[Z_NEED_DICT - (Z_BUF_ERROR)];
|
return Z_BUF_ERROR;
|
}
|
|
// Start a new block or continue the current one.
|
if (strm.avail_in !== 0 || lookahead !== 0 || (flush != Z_NO_FLUSH && status != FINISH_STATE)) {
|
bstate = -1;
|
switch (config_table[level].func) {
|
case STORED:
|
bstate = deflate_stored(flush);
|
break;
|
case FAST:
|
bstate = deflate_fast(flush);
|
break;
|
case SLOW:
|
bstate = deflate_slow(flush);
|
break;
|
default:
|
}
|
|
if (bstate == FinishStarted || bstate == FinishDone) {
|
status = FINISH_STATE;
|
}
|
if (bstate == NeedMore || bstate == FinishStarted) {
|
if (strm.avail_out === 0) {
|
last_flush = -1; // avoid BUF_ERROR next call, see above
|
}
|
return Z_OK;
|
// If flush != Z_NO_FLUSH && avail_out === 0, the next call
|
// of deflate should use the same flush parameter to make sure
|
// that the flush is complete. So we don't have to output an
|
// empty block here, this will be done at next call. This also
|
// ensures that for a very small output buffer, we emit at most
|
// one empty block.
|
}
|
|
if (bstate == BlockDone) {
|
if (flush == Z_PARTIAL_FLUSH) {
|
_tr_align();
|
} else { // FULL_FLUSH or SYNC_FLUSH
|
_tr_stored_block(0, 0, false);
|
// For a full flush, this empty block will be recognized
|
// as a special marker by inflate_sync().
|
if (flush == Z_FULL_FLUSH) {
|
// state.head[s.hash_size-1]=0;
|
for (i = 0; i < hash_size/*-1*/; i++)
|
// forget history
|
head[i] = 0;
|
}
|
}
|
strm.flush_pending();
|
if (strm.avail_out === 0) {
|
last_flush = -1; // avoid BUF_ERROR at next call, see above
|
return Z_OK;
|
}
|
}
|
}
|
|
if (flush != Z_FINISH)
|
return Z_OK;
|
return Z_STREAM_END;
|
};
|
}
|
|
// ZStream
|
|
function ZStream() {
|
var that = this;
|
that.next_in_index = 0;
|
that.next_out_index = 0;
|
// that.next_in; // next input byte
|
that.avail_in = 0; // number of bytes available at next_in
|
that.total_in = 0; // total nb of input bytes read so far
|
// that.next_out; // next output byte should be put there
|
that.avail_out = 0; // remaining free space at next_out
|
that.total_out = 0; // total nb of bytes output so far
|
// that.msg;
|
// that.dstate;
|
}
|
|
ZStream.prototype = {
|
deflateInit : function(level, bits) {
|
var that = this;
|
that.dstate = new Deflate();
|
if (!bits)
|
bits = MAX_BITS;
|
return that.dstate.deflateInit(that, level, bits);
|
},
|
|
deflate : function(flush) {
|
var that = this;
|
if (!that.dstate) {
|
return Z_STREAM_ERROR;
|
}
|
return that.dstate.deflate(that, flush);
|
},
|
|
deflateEnd : function() {
|
var that = this;
|
if (!that.dstate)
|
return Z_STREAM_ERROR;
|
var ret = that.dstate.deflateEnd();
|
that.dstate = null;
|
return ret;
|
},
|
|
deflateParams : function(level, strategy) {
|
var that = this;
|
if (!that.dstate)
|
return Z_STREAM_ERROR;
|
return that.dstate.deflateParams(that, level, strategy);
|
},
|
|
deflateSetDictionary : function(dictionary, dictLength) {
|
var that = this;
|
if (!that.dstate)
|
return Z_STREAM_ERROR;
|
return that.dstate.deflateSetDictionary(that, dictionary, dictLength);
|
},
|
|
// Read a new buffer from the current input stream, update the
|
// total number of bytes read. All deflate() input goes through
|
// this function so some applications may wish to modify it to avoid
|
// allocating a large strm->next_in buffer and copying from it.
|
// (See also flush_pending()).
|
read_buf : function(buf, start, size) {
|
var that = this;
|
var len = that.avail_in;
|
if (len > size)
|
len = size;
|
if (len === 0)
|
return 0;
|
that.avail_in -= len;
|
buf.set(that.next_in.subarray(that.next_in_index, that.next_in_index + len), start);
|
that.next_in_index += len;
|
that.total_in += len;
|
return len;
|
},
|
|
// Flush as much pending output as possible. All deflate() output goes
|
// through this function so some applications may wish to modify it
|
// to avoid allocating a large strm->next_out buffer and copying into it.
|
// (See also read_buf()).
|
flush_pending : function() {
|
var that = this;
|
var len = that.dstate.pending;
|
|
if (len > that.avail_out)
|
len = that.avail_out;
|
if (len === 0)
|
return;
|
|
// if (that.dstate.pending_buf.length <= that.dstate.pending_out || that.next_out.length <= that.next_out_index
|
// || that.dstate.pending_buf.length < (that.dstate.pending_out + len) || that.next_out.length < (that.next_out_index +
|
// len)) {
|
// console.log(that.dstate.pending_buf.length + ", " + that.dstate.pending_out + ", " + that.next_out.length + ", " +
|
// that.next_out_index + ", " + len);
|
// console.log("avail_out=" + that.avail_out);
|
// }
|
|
that.next_out.set(that.dstate.pending_buf.subarray(that.dstate.pending_out, that.dstate.pending_out + len), that.next_out_index);
|
|
that.next_out_index += len;
|
that.dstate.pending_out += len;
|
that.total_out += len;
|
that.avail_out -= len;
|
that.dstate.pending -= len;
|
if (that.dstate.pending === 0) {
|
that.dstate.pending_out = 0;
|
}
|
}
|
};
|
|
// Deflater
|
|
function Deflater(level) {
|
var that = this;
|
var z = new ZStream();
|
var bufsize = 512;
|
var flush = Z_NO_FLUSH;
|
var buf = new Uint8Array(bufsize);
|
|
if (typeof level == "undefined")
|
level = Z_DEFAULT_COMPRESSION;
|
z.deflateInit(level);
|
z.next_out = buf;
|
|
that.append = function(data, onprogress) {
|
var err, buffers = [], lastIndex = 0, bufferIndex = 0, bufferSize = 0, array;
|
if (!data.length)
|
return;
|
z.next_in_index = 0;
|
z.next_in = data;
|
z.avail_in = data.length;
|
do {
|
z.next_out_index = 0;
|
z.avail_out = bufsize;
|
err = z.deflate(flush);
|
if (err != Z_OK)
|
throw "deflating: " + z.msg;
|
if (z.next_out_index)
|
if (z.next_out_index == bufsize)
|
buffers.push(new Uint8Array(buf));
|
else
|
buffers.push(new Uint8Array(buf.subarray(0, z.next_out_index)));
|
bufferSize += z.next_out_index;
|
if (onprogress && z.next_in_index > 0 && z.next_in_index != lastIndex) {
|
onprogress(z.next_in_index);
|
lastIndex = z.next_in_index;
|
}
|
} while (z.avail_in > 0 || z.avail_out === 0);
|
array = new Uint8Array(bufferSize);
|
buffers.forEach(function(chunk) {
|
array.set(chunk, bufferIndex);
|
bufferIndex += chunk.length;
|
});
|
return array;
|
};
|
that.flush = function() {
|
var err, buffers = [], bufferIndex = 0, bufferSize = 0, array;
|
do {
|
z.next_out_index = 0;
|
z.avail_out = bufsize;
|
err = z.deflate(Z_FINISH);
|
if (err != Z_STREAM_END && err != Z_OK)
|
throw "deflating: " + z.msg;
|
if (bufsize - z.avail_out > 0)
|
buffers.push(new Uint8Array(buf.subarray(0, z.next_out_index)));
|
bufferSize += z.next_out_index;
|
} while (z.avail_in > 0 || z.avail_out === 0);
|
z.deflateEnd();
|
array = new Uint8Array(bufferSize);
|
buffers.forEach(function(chunk) {
|
array.set(chunk, bufferIndex);
|
bufferIndex += chunk.length;
|
});
|
return array;
|
};
|
}
|
|
var deflater;
|
|
if (obj.zip)
|
obj.zip.Deflater = Deflater;
|
else {
|
deflater = new Deflater();
|
obj.addEventListener("message", function(event) {
|
var message = event.data;
|
if (message.init) {
|
deflater = new Deflater(message.level);
|
obj.postMessage({
|
oninit : true
|
});
|
}
|
if (message.append)
|
obj.postMessage({
|
onappend : true,
|
data : deflater.append(message.data, function(current) {
|
obj.postMessage({
|
progress : true,
|
current : current
|
});
|
})
|
});
|
if (message.flush)
|
obj.postMessage({
|
onflush : true,
|
data : deflater.flush()
|
});
|
}, false);
|
}
|
|
})(this);
|
