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- /*
- Copyright (c) 2013 Gildas Lormeau. All rights reserved.
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions are met:
- 1. Redistributions of source code must retain the above copyright notice,
- this list of conditions and the following disclaimer.
- 2. Redistributions in binary form must reproduce the above copyright
- notice, this list of conditions and the following disclaimer in
- the documentation and/or other materials provided with the distribution.
- 3. The names of the authors may not be used to endorse or promote products
- derived from this software without specific prior written permission.
- THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
- INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
- FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
- INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
- INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
- OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
- LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
- NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
- EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
- /*
- * This program is based on JZlib 1.0.2 ymnk, JCraft,Inc.
- * JZlib is based on zlib-1.1.3, so all credit should go authors
- * Jean-loup Gailly(jloup@gzip.org) and Mark Adler(madler@alumni.caltech.edu)
- * and contributors of zlib.
- */
- (function(obj) {
- // Global
- var MAX_BITS = 15;
- var D_CODES = 30;
- var BL_CODES = 19;
- var LENGTH_CODES = 29;
- var LITERALS = 256;
- var L_CODES = (LITERALS + 1 + LENGTH_CODES);
- var HEAP_SIZE = (2 * L_CODES + 1);
- var END_BLOCK = 256;
- // Bit length codes must not exceed MAX_BL_BITS bits
- var MAX_BL_BITS = 7;
- // repeat previous bit length 3-6 times (2 bits of repeat count)
- var REP_3_6 = 16;
- // repeat a zero length 3-10 times (3 bits of repeat count)
- var REPZ_3_10 = 17;
- // repeat a zero length 11-138 times (7 bits of repeat count)
- var REPZ_11_138 = 18;
- // The lengths of the bit length codes are sent in order of decreasing
- // probability, to avoid transmitting the lengths for unused bit
- // length codes.
- var Buf_size = 8 * 2;
- // JZlib version : "1.0.2"
- var Z_DEFAULT_COMPRESSION = -1;
- // compression strategy
- var Z_FILTERED = 1;
- var Z_HUFFMAN_ONLY = 2;
- var Z_DEFAULT_STRATEGY = 0;
- var Z_NO_FLUSH = 0;
- var Z_PARTIAL_FLUSH = 1;
- var Z_FULL_FLUSH = 3;
- var Z_FINISH = 4;
- var Z_OK = 0;
- var Z_STREAM_END = 1;
- var Z_NEED_DICT = 2;
- var Z_STREAM_ERROR = -2;
- var Z_DATA_ERROR = -3;
- var Z_BUF_ERROR = -5;
- // Tree
- // see definition of array dist_code below
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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 ];
- function Tree() {
- var that = this;
- // dyn_tree; // the dynamic tree
- // max_code; // largest code with non zero frequency
- // stat_desc; // the corresponding static tree
- // 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.
- function gen_bitlen(s) {
- var tree = that.dyn_tree;
- var stree = that.stat_desc.static_tree;
- var extra = that.stat_desc.extra_bits;
- var base = that.stat_desc.extra_base;
- var max_length = that.stat_desc.max_length;
- 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 <= MAX_BITS; bits++)
- s.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[s.heap[s.heap_max] * 2 + 1] = 0; // root of the heap
- for (h = s.heap_max + 1; h < HEAP_SIZE; h++) {
- n = s.heap[h];
- bits = tree[tree[n * 2 + 1] * 2 + 1] + 1;
- if (bits > max_length) {
- bits = max_length;
- overflow++;
- }
- tree[n * 2 + 1] = bits;
- // We overwrite tree[n*2+1] which is no longer needed
- if (n > that.max_code)
- continue; // not a leaf node
- s.bl_count[bits]++;
- xbits = 0;
- if (n >= base)
- xbits = extra[n - base];
- f = tree[n * 2];
- s.opt_len += f * (bits + xbits);
- if (stree)
- s.static_len += f * (stree[n * 2 + 1] + 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 (s.bl_count[bits] === 0)
- bits--;
- s.bl_count[bits]--; // move one leaf down the tree
- s.bl_count[bits + 1] += 2; // move one overflow item as its brother
- s.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);
- for (bits = max_length; bits !== 0; bits--) {
- n = s.bl_count[bits];
- while (n !== 0) {
- m = s.heap[--h];
- if (m > that.max_code)
- continue;
- if (tree[m * 2 + 1] != bits) {
- s.opt_len += (bits - tree[m * 2 + 1]) * tree[m * 2];
- tree[m * 2 + 1] = bits;
- }
- n--;
- }
- }
- }
- // Reverse the first len bits of a code, using straightforward code (a
- // faster
- // method would use a table)
- // IN assertion: 1 <= len <= 15
- function bi_reverse(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;
- }
- // 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.
- function gen_codes(tree, // the tree to decorate
- max_code, // largest code with non zero frequency
- bl_count // number of codes at each bit length
- ) {
- var next_code = []; // next code value for each
- // bit length
- var code = 0; // running code value
- var bits; // bit index
- var n; // code index
- var len;
- // The distribution counts are first used to generate the code values
- // without bit reversal.
- for (bits = 1; bits <= MAX_BITS; bits++) {
- next_code[bits] = code = ((code + bl_count[bits - 1]) << 1);
- }
- // Check that the bit counts in bl_count are consistent. The last code
- // must be all ones.
- // Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
- // "inconsistent bit counts");
- // Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
- for (n = 0; n <= max_code; n++) {
- len = tree[n * 2 + 1];
- if (len === 0)
- continue;
- // Now reverse the bits
- tree[n * 2] = 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.
- that.build_tree = function(s) {
- var tree = that.dyn_tree;
- var stree = that.stat_desc.static_tree;
- var elems = that.stat_desc.elems;
- var n, m; // iterate over heap elements
- var max_code = -1; // largest code with non zero frequency
- var node; // new node being created
- // Construct the initial heap, with least frequent element in
- // heap[1]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
- // heap[0] is not used.
- s.heap_len = 0;
- s.heap_max = HEAP_SIZE;
- for (n = 0; n < elems; n++) {
- if (tree[n * 2] !== 0) {
- s.heap[++s.heap_len] = max_code = n;
- s.depth[n] = 0;
- } else {
- tree[n * 2 + 1] = 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 (s.heap_len < 2) {
- node = s.heap[++s.heap_len] = max_code < 2 ? ++max_code : 0;
- tree[node * 2] = 1;
- s.depth[node] = 0;
- s.opt_len--;
- if (stree)
- s.static_len -= stree[node * 2 + 1];
- // node is 0 or 1 so it does not have extra bits
- }
- that.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 = Math.floor(s.heap_len / 2); n >= 1; n--)
- s.pqdownheap(tree, n);
- // Construct the Huffman tree by repeatedly combining the least two
- // frequent nodes.
- node = elems; // next internal node of the tree
- do {
- // n = node of least frequency
- n = s.heap[1];
- s.heap[1] = s.heap[s.heap_len--];
- s.pqdownheap(tree, 1);
- m = s.heap[1]; // m = node of next least frequency
- s.heap[--s.heap_max] = n; // keep the nodes sorted by frequency
- s.heap[--s.heap_max] = m;
- // Create a new node father of n and m
- tree[node * 2] = (tree[n * 2] + tree[m * 2]);
- s.depth[node] = Math.max(s.depth[n], s.depth[m]) + 1;
- tree[n * 2 + 1] = tree[m * 2 + 1] = node;
- // and insert the new node in the heap
- s.heap[1] = node++;
- s.pqdownheap(tree, 1);
- } while (s.heap_len >= 2);
- s.heap[--s.heap_max] = s.heap[1];
- // At this point, the fields freq and dad are set. We can now
- // generate the bit lengths.
- gen_bitlen(s);
- // The field len is now set, we can generate the bit codes
- gen_codes(tree, that.max_code, s.bl_count);
- };
- }
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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 ];
- 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 ];
- 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,
- 24576 ];
- // 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.
- Tree.d_code = function(dist) {
- return ((dist) < 256 ? _dist_code[dist] : _dist_code[256 + ((dist) >>> 7)]);
- };
- // extra bits for each length code
- 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 ];
- // extra bits for each distance code
- 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 ];
- // extra bits for each bit length code
- Tree.extra_blbits = [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 ];
- Tree.bl_order = [ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 ];
- // StaticTree
- function StaticTree(static_tree, extra_bits, extra_base, elems, max_length) {
- var that = this;
- that.static_tree = static_tree;
- that.extra_bits = extra_bits;
- that.extra_base = extra_base;
- that.elems = elems;
- that.max_length = max_length;
- }
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 99, 8, 227, 8 ];
- 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,
- 25, 5, 5, 5, 21, 5, 13, 5, 29, 5, 3, 5, 19, 5, 11, 5, 27, 5, 7, 5, 23, 5 ];
- 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);
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