deflate.js 69 KB

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  1. /*
  2. Copyright (c) 2013 Gildas Lormeau. All rights reserved.
  3. Redistribution and use in source and binary forms, with or without
  4. modification, are permitted provided that the following conditions are met:
  5. 1. Redistributions of source code must retain the above copyright notice,
  6. this list of conditions and the following disclaimer.
  7. 2. Redistributions in binary form must reproduce the above copyright
  8. notice, this list of conditions and the following disclaimer in
  9. the documentation and/or other materials provided with the distribution.
  10. 3. The names of the authors may not be used to endorse or promote products
  11. derived from this software without specific prior written permission.
  12. THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
  13. INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  14. FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
  15. INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
  16. INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  17. LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
  18. OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  19. LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  20. NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  21. EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  22. */
  23. /*
  24. * This program is based on JZlib 1.0.2 ymnk, JCraft,Inc.
  25. * JZlib is based on zlib-1.1.3, so all credit should go authors
  26. * Jean-loup Gailly([email protected]) and Mark Adler([email protected])
  27. * and contributors of zlib.
  28. */
  29. (function(global) {
  30. "use strict";
  31. // Global
  32. var MAX_BITS = 15;
  33. var D_CODES = 30;
  34. var BL_CODES = 19;
  35. var LENGTH_CODES = 29;
  36. var LITERALS = 256;
  37. var L_CODES = (LITERALS + 1 + LENGTH_CODES);
  38. var HEAP_SIZE = (2 * L_CODES + 1);
  39. var END_BLOCK = 256;
  40. // Bit length codes must not exceed MAX_BL_BITS bits
  41. var MAX_BL_BITS = 7;
  42. // repeat previous bit length 3-6 times (2 bits of repeat count)
  43. var REP_3_6 = 16;
  44. // repeat a zero length 3-10 times (3 bits of repeat count)
  45. var REPZ_3_10 = 17;
  46. // repeat a zero length 11-138 times (7 bits of repeat count)
  47. var REPZ_11_138 = 18;
  48. // The lengths of the bit length codes are sent in order of decreasing
  49. // probability, to avoid transmitting the lengths for unused bit
  50. // length codes.
  51. var Buf_size = 8 * 2;
  52. // JZlib version : "1.0.2"
  53. var Z_DEFAULT_COMPRESSION = -1;
  54. // compression strategy
  55. var Z_FILTERED = 1;
  56. var Z_HUFFMAN_ONLY = 2;
  57. var Z_DEFAULT_STRATEGY = 0;
  58. var Z_NO_FLUSH = 0;
  59. var Z_PARTIAL_FLUSH = 1;
  60. var Z_FULL_FLUSH = 3;
  61. var Z_FINISH = 4;
  62. var Z_OK = 0;
  63. var Z_STREAM_END = 1;
  64. var Z_NEED_DICT = 2;
  65. var Z_STREAM_ERROR = -2;
  66. var Z_DATA_ERROR = -3;
  67. var Z_BUF_ERROR = -5;
  68. // Tree
  69. // see definition of array dist_code below
  70. 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,
  71. 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,
  72. 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,
  73. 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,
  74. 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,
  75. 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,
  76. 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,
  77. 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,
  78. 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,
  79. 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,
  80. 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,
  81. 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,
  82. 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,
  83. 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 ];
  84. function Tree() {
  85. var that = this;
  86. // dyn_tree; // the dynamic tree
  87. // max_code; // largest code with non zero frequency
  88. // stat_desc; // the corresponding static tree
  89. // Compute the optimal bit lengths for a tree and update the total bit
  90. // length
  91. // for the current block.
  92. // IN assertion: the fields freq and dad are set, heap[heap_max] and
  93. // above are the tree nodes sorted by increasing frequency.
  94. // OUT assertions: the field len is set to the optimal bit length, the
  95. // array bl_count contains the frequencies for each bit length.
  96. // The length opt_len is updated; static_len is also updated if stree is
  97. // not null.
  98. function gen_bitlen(s) {
  99. var tree = that.dyn_tree;
  100. var stree = that.stat_desc.static_tree;
  101. var extra = that.stat_desc.extra_bits;
  102. var base = that.stat_desc.extra_base;
  103. var max_length = that.stat_desc.max_length;
  104. var h; // heap index
  105. var n, m; // iterate over the tree elements
  106. var bits; // bit length
  107. var xbits; // extra bits
  108. var f; // frequency
  109. var overflow = 0; // number of elements with bit length too large
  110. for (bits = 0; bits <= MAX_BITS; bits++)
  111. s.bl_count[bits] = 0;
  112. // In a first pass, compute the optimal bit lengths (which may
  113. // overflow in the case of the bit length tree).
  114. tree[s.heap[s.heap_max] * 2 + 1] = 0; // root of the heap
  115. for (h = s.heap_max + 1; h < HEAP_SIZE; h++) {
  116. n = s.heap[h];
  117. bits = tree[tree[n * 2 + 1] * 2 + 1] + 1;
  118. if (bits > max_length) {
  119. bits = max_length;
  120. overflow++;
  121. }
  122. tree[n * 2 + 1] = bits;
  123. // We overwrite tree[n*2+1] which is no longer needed
  124. if (n > that.max_code)
  125. continue; // not a leaf node
  126. s.bl_count[bits]++;
  127. xbits = 0;
  128. if (n >= base)
  129. xbits = extra[n - base];
  130. f = tree[n * 2];
  131. s.opt_len += f * (bits + xbits);
  132. if (stree)
  133. s.static_len += f * (stree[n * 2 + 1] + xbits);
  134. }
  135. if (overflow === 0)
  136. return;
  137. // This happens for example on obj2 and pic of the Calgary corpus
  138. // Find the first bit length which could increase:
  139. do {
  140. bits = max_length - 1;
  141. while (s.bl_count[bits] === 0)
  142. bits--;
  143. s.bl_count[bits]--; // move one leaf down the tree
  144. s.bl_count[bits + 1] += 2; // move one overflow item as its brother
  145. s.bl_count[max_length]--;
  146. // The brother of the overflow item also moves one step up,
  147. // but this does not affect bl_count[max_length]
  148. overflow -= 2;
  149. } while (overflow > 0);
  150. for (bits = max_length; bits !== 0; bits--) {
  151. n = s.bl_count[bits];
  152. while (n !== 0) {
  153. m = s.heap[--h];
  154. if (m > that.max_code)
  155. continue;
  156. if (tree[m * 2 + 1] != bits) {
  157. s.opt_len += (bits - tree[m * 2 + 1]) * tree[m * 2];
  158. tree[m * 2 + 1] = bits;
  159. }
  160. n--;
  161. }
  162. }
  163. }
  164. // Reverse the first len bits of a code, using straightforward code (a
  165. // faster
  166. // method would use a table)
  167. // IN assertion: 1 <= len <= 15
  168. function bi_reverse(code, // the value to invert
  169. len // its bit length
  170. ) {
  171. var res = 0;
  172. do {
  173. res |= code & 1;
  174. code >>>= 1;
  175. res <<= 1;
  176. } while (--len > 0);
  177. return res >>> 1;
  178. }
  179. // Generate the codes for a given tree and bit counts (which need not be
  180. // optimal).
  181. // IN assertion: the array bl_count contains the bit length statistics for
  182. // the given tree and the field len is set for all tree elements.
  183. // OUT assertion: the field code is set for all tree elements of non
  184. // zero code length.
  185. function gen_codes(tree, // the tree to decorate
  186. max_code, // largest code with non zero frequency
  187. bl_count // number of codes at each bit length
  188. ) {
  189. var next_code = []; // next code value for each
  190. // bit length
  191. var code = 0; // running code value
  192. var bits; // bit index
  193. var n; // code index
  194. var len;
  195. // The distribution counts are first used to generate the code values
  196. // without bit reversal.
  197. for (bits = 1; bits <= MAX_BITS; bits++) {
  198. next_code[bits] = code = ((code + bl_count[bits - 1]) << 1);
  199. }
  200. // Check that the bit counts in bl_count are consistent. The last code
  201. // must be all ones.
  202. // Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
  203. // "inconsistent bit counts");
  204. // Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
  205. for (n = 0; n <= max_code; n++) {
  206. len = tree[n * 2 + 1];
  207. if (len === 0)
  208. continue;
  209. // Now reverse the bits
  210. tree[n * 2] = bi_reverse(next_code[len]++, len);
  211. }
  212. }
  213. // Construct one Huffman tree and assigns the code bit strings and lengths.
  214. // Update the total bit length for the current block.
  215. // IN assertion: the field freq is set for all tree elements.
  216. // OUT assertions: the fields len and code are set to the optimal bit length
  217. // and corresponding code. The length opt_len is updated; static_len is
  218. // also updated if stree is not null. The field max_code is set.
  219. that.build_tree = function(s) {
  220. var tree = that.dyn_tree;
  221. var stree = that.stat_desc.static_tree;
  222. var elems = that.stat_desc.elems;
  223. var n, m; // iterate over heap elements
  224. var max_code = -1; // largest code with non zero frequency
  225. var node; // new node being created
  226. // Construct the initial heap, with least frequent element in
  227. // heap[1]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
  228. // heap[0] is not used.
  229. s.heap_len = 0;
  230. s.heap_max = HEAP_SIZE;
  231. for (n = 0; n < elems; n++) {
  232. if (tree[n * 2] !== 0) {
  233. s.heap[++s.heap_len] = max_code = n;
  234. s.depth[n] = 0;
  235. } else {
  236. tree[n * 2 + 1] = 0;
  237. }
  238. }
  239. // The pkzip format requires that at least one distance code exists,
  240. // and that at least one bit should be sent even if there is only one
  241. // possible code. So to avoid special checks later on we force at least
  242. // two codes of non zero frequency.
  243. while (s.heap_len < 2) {
  244. node = s.heap[++s.heap_len] = max_code < 2 ? ++max_code : 0;
  245. tree[node * 2] = 1;
  246. s.depth[node] = 0;
  247. s.opt_len--;
  248. if (stree)
  249. s.static_len -= stree[node * 2 + 1];
  250. // node is 0 or 1 so it does not have extra bits
  251. }
  252. that.max_code = max_code;
  253. // The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
  254. // establish sub-heaps of increasing lengths:
  255. for (n = Math.floor(s.heap_len / 2); n >= 1; n--)
  256. s.pqdownheap(tree, n);
  257. // Construct the Huffman tree by repeatedly combining the least two
  258. // frequent nodes.
  259. node = elems; // next internal node of the tree
  260. do {
  261. // n = node of least frequency
  262. n = s.heap[1];
  263. s.heap[1] = s.heap[s.heap_len--];
  264. s.pqdownheap(tree, 1);
  265. m = s.heap[1]; // m = node of next least frequency
  266. s.heap[--s.heap_max] = n; // keep the nodes sorted by frequency
  267. s.heap[--s.heap_max] = m;
  268. // Create a new node father of n and m
  269. tree[node * 2] = (tree[n * 2] + tree[m * 2]);
  270. s.depth[node] = Math.max(s.depth[n], s.depth[m]) + 1;
  271. tree[n * 2 + 1] = tree[m * 2 + 1] = node;
  272. // and insert the new node in the heap
  273. s.heap[1] = node++;
  274. s.pqdownheap(tree, 1);
  275. } while (s.heap_len >= 2);
  276. s.heap[--s.heap_max] = s.heap[1];
  277. // At this point, the fields freq and dad are set. We can now
  278. // generate the bit lengths.
  279. gen_bitlen(s);
  280. // The field len is now set, we can generate the bit codes
  281. gen_codes(tree, that.max_code, s.bl_count);
  282. };
  283. }
  284. 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,
  285. 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,
  286. 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,
  287. 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,
  288. 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,
  289. 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,
  290. 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 ];
  291. 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 ];
  292. 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,
  293. 24576 ];
  294. // Mapping from a distance to a distance code. dist is the distance - 1 and
  295. // must not have side effects. _dist_code[256] and _dist_code[257] are never
  296. // used.
  297. Tree.d_code = function(dist) {
  298. return ((dist) < 256 ? _dist_code[dist] : _dist_code[256 + ((dist) >>> 7)]);
  299. };
  300. // extra bits for each length code
  301. 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 ];
  302. // extra bits for each distance code
  303. 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 ];
  304. // extra bits for each bit length code
  305. Tree.extra_blbits = [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 ];
  306. Tree.bl_order = [ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 ];
  307. // StaticTree
  308. function StaticTree(static_tree, extra_bits, extra_base, elems, max_length) {
  309. var that = this;
  310. that.static_tree = static_tree;
  311. that.extra_bits = extra_bits;
  312. that.extra_base = extra_base;
  313. that.elems = elems;
  314. that.max_length = max_length;
  315. }
  316. 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,
  317. 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,
  318. 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,
  319. 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,
  320. 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,
  321. 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,
  322. 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,
  323. 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,
  324. 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,
  325. 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,
  326. 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,
  327. 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,
  328. 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,
  329. 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,
  330. 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,
  331. 99, 8, 227, 8 ];
  332. 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,
  333. 25, 5, 5, 5, 21, 5, 13, 5, 29, 5, 3, 5, 19, 5, 11, 5, 27, 5, 7, 5, 23, 5 ];
  334. StaticTree.static_l_desc = new StaticTree(StaticTree.static_ltree, Tree.extra_lbits, LITERALS + 1, L_CODES, MAX_BITS);
  335. StaticTree.static_d_desc = new StaticTree(StaticTree.static_dtree, Tree.extra_dbits, 0, D_CODES, MAX_BITS);
  336. StaticTree.static_bl_desc = new StaticTree(null, Tree.extra_blbits, 0, BL_CODES, MAX_BL_BITS);
  337. // Deflate
  338. var MAX_MEM_LEVEL = 9;
  339. var DEF_MEM_LEVEL = 8;
  340. function Config(good_length, max_lazy, nice_length, max_chain, func) {
  341. var that = this;
  342. that.good_length = good_length;
  343. that.max_lazy = max_lazy;
  344. that.nice_length = nice_length;
  345. that.max_chain = max_chain;
  346. that.func = func;
  347. }
  348. var STORED = 0;
  349. var FAST = 1;
  350. var SLOW = 2;
  351. 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),
  352. 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),
  353. new Config(32, 128, 258, 1024, SLOW), new Config(32, 258, 258, 4096, SLOW) ];
  354. var z_errmsg = [ "need dictionary", // Z_NEED_DICT
  355. // 2
  356. "stream end", // Z_STREAM_END 1
  357. "", // Z_OK 0
  358. "", // Z_ERRNO (-1)
  359. "stream error", // Z_STREAM_ERROR (-2)
  360. "data error", // Z_DATA_ERROR (-3)
  361. "", // Z_MEM_ERROR (-4)
  362. "buffer error", // Z_BUF_ERROR (-5)
  363. "",// Z_VERSION_ERROR (-6)
  364. "" ];
  365. // block not completed, need more input or more output
  366. var NeedMore = 0;
  367. // block flush performed
  368. var BlockDone = 1;
  369. // finish started, need only more output at next deflate
  370. var FinishStarted = 2;
  371. // finish done, accept no more input or output
  372. var FinishDone = 3;
  373. // preset dictionary flag in zlib header
  374. var PRESET_DICT = 0x20;
  375. var INIT_STATE = 42;
  376. var BUSY_STATE = 113;
  377. var FINISH_STATE = 666;
  378. // The deflate compression method
  379. var Z_DEFLATED = 8;
  380. var STORED_BLOCK = 0;
  381. var STATIC_TREES = 1;
  382. var DYN_TREES = 2;
  383. var MIN_MATCH = 3;
  384. var MAX_MATCH = 258;
  385. var MIN_LOOKAHEAD = (MAX_MATCH + MIN_MATCH + 1);
  386. function smaller(tree, n, m, depth) {
  387. var tn2 = tree[n * 2];
  388. var tm2 = tree[m * 2];
  389. return (tn2 < tm2 || (tn2 == tm2 && depth[n] <= depth[m]));
  390. }
  391. function Deflate() {
  392. var that = this;
  393. var strm; // pointer back to this zlib stream
  394. var status; // as the name implies
  395. // pending_buf; // output still pending
  396. var pending_buf_size; // size of pending_buf
  397. // pending_out; // next pending byte to output to the stream
  398. // pending; // nb of bytes in the pending buffer
  399. var method; // STORED (for zip only) or DEFLATED
  400. var last_flush; // value of flush param for previous deflate call
  401. var w_size; // LZ77 window size (32K by default)
  402. var w_bits; // log2(w_size) (8..16)
  403. var w_mask; // w_size - 1
  404. var window;
  405. // Sliding window. Input bytes are read into the second half of the window,
  406. // and move to the first half later to keep a dictionary of at least wSize
  407. // bytes. With this organization, matches are limited to a distance of
  408. // wSize-MAX_MATCH bytes, but this ensures that IO is always
  409. // performed with a length multiple of the block size. Also, it limits
  410. // the window size to 64K, which is quite useful on MSDOS.
  411. // To do: use the user input buffer as sliding window.
  412. var window_size;
  413. // Actual size of window: 2*wSize, except when the user input buffer
  414. // is directly used as sliding window.
  415. var prev;
  416. // Link to older string with same hash index. To limit the size of this
  417. // array to 64K, this link is maintained only for the last 32K strings.
  418. // An index in this array is thus a window index modulo 32K.
  419. var head; // Heads of the hash chains or NIL.
  420. var ins_h; // hash index of string to be inserted
  421. var hash_size; // number of elements in hash table
  422. var hash_bits; // log2(hash_size)
  423. var hash_mask; // hash_size-1
  424. // Number of bits by which ins_h must be shifted at each input
  425. // step. It must be such that after MIN_MATCH steps, the oldest
  426. // byte no longer takes part in the hash key, that is:
  427. // hash_shift * MIN_MATCH >= hash_bits
  428. var hash_shift;
  429. // Window position at the beginning of the current output block. Gets
  430. // negative when the window is moved backwards.
  431. var block_start;
  432. var match_length; // length of best match
  433. var prev_match; // previous match
  434. var match_available; // set if previous match exists
  435. var strstart; // start of string to insert
  436. var match_start; // start of matching string
  437. var lookahead; // number of valid bytes ahead in window
  438. // Length of the best match at previous step. Matches not greater than this
  439. // are discarded. This is used in the lazy match evaluation.
  440. var prev_length;
  441. // To speed up deflation, hash chains are never searched beyond this
  442. // length. A higher limit improves compression ratio but degrades the speed.
  443. var max_chain_length;
  444. // Attempt to find a better match only when the current match is strictly
  445. // smaller than this value. This mechanism is used only for compression
  446. // levels >= 4.
  447. var max_lazy_match;
  448. // Insert new strings in the hash table only if the match length is not
  449. // greater than this length. This saves time but degrades compression.
  450. // max_insert_length is used only for compression levels <= 3.
  451. var level; // compression level (1..9)
  452. var strategy; // favor or force Huffman coding
  453. // Use a faster search when the previous match is longer than this
  454. var good_match;
  455. // Stop searching when current match exceeds this
  456. var nice_match;
  457. var dyn_ltree; // literal and length tree
  458. var dyn_dtree; // distance tree
  459. var bl_tree; // Huffman tree for bit lengths
  460. var l_desc = new Tree(); // desc for literal tree
  461. var d_desc = new Tree(); // desc for distance tree
  462. var bl_desc = new Tree(); // desc for bit length tree
  463. // that.heap_len; // number of elements in the heap
  464. // that.heap_max; // element of largest frequency
  465. // The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
  466. // The same heap array is used to build all trees.
  467. // Depth of each subtree used as tie breaker for trees of equal frequency
  468. that.depth = [];
  469. var l_buf; // index for literals or lengths */
  470. // Size of match buffer for literals/lengths. There are 4 reasons for
  471. // limiting lit_bufsize to 64K:
  472. // - frequencies can be kept in 16 bit counters
  473. // - if compression is not successful for the first block, all input
  474. // data is still in the window so we can still emit a stored block even
  475. // when input comes from standard input. (This can also be done for
  476. // all blocks if lit_bufsize is not greater than 32K.)
  477. // - if compression is not successful for a file smaller than 64K, we can
  478. // even emit a stored file instead of a stored block (saving 5 bytes).
  479. // This is applicable only for zip (not gzip or zlib).
  480. // - creating new Huffman trees less frequently may not provide fast
  481. // adaptation to changes in the input data statistics. (Take for
  482. // example a binary file with poorly compressible code followed by
  483. // a highly compressible string table.) Smaller buffer sizes give
  484. // fast adaptation but have of course the overhead of transmitting
  485. // trees more frequently.
  486. // - I can't count above 4
  487. var lit_bufsize;
  488. var last_lit; // running index in l_buf
  489. // Buffer for distances. To simplify the code, d_buf and l_buf have
  490. // the same number of elements. To use different lengths, an extra flag
  491. // array would be necessary.
  492. var d_buf; // index of pendig_buf
  493. // that.opt_len; // bit length of current block with optimal trees
  494. // that.static_len; // bit length of current block with static trees
  495. var matches; // number of string matches in current block
  496. var last_eob_len; // bit length of EOB code for last block
  497. // Output buffer. bits are inserted starting at the bottom (least
  498. // significant bits).
  499. var bi_buf;
  500. // Number of valid bits in bi_buf. All bits above the last valid bit
  501. // are always zero.
  502. var bi_valid;
  503. // number of codes at each bit length for an optimal tree
  504. that.bl_count = [];
  505. // heap used to build the Huffman trees
  506. that.heap = [];
  507. dyn_ltree = [];
  508. dyn_dtree = [];
  509. bl_tree = [];
  510. function lm_init() {
  511. var i;
  512. window_size = 2 * w_size;
  513. head[hash_size - 1] = 0;
  514. for (i = 0; i < hash_size - 1; i++) {
  515. head[i] = 0;
  516. }
  517. // Set the default configuration parameters:
  518. max_lazy_match = config_table[level].max_lazy;
  519. good_match = config_table[level].good_length;
  520. nice_match = config_table[level].nice_length;
  521. max_chain_length = config_table[level].max_chain;
  522. strstart = 0;
  523. block_start = 0;
  524. lookahead = 0;
  525. match_length = prev_length = MIN_MATCH - 1;
  526. match_available = 0;
  527. ins_h = 0;
  528. }
  529. function init_block() {
  530. var i;
  531. // Initialize the trees.
  532. for (i = 0; i < L_CODES; i++)
  533. dyn_ltree[i * 2] = 0;
  534. for (i = 0; i < D_CODES; i++)
  535. dyn_dtree[i * 2] = 0;
  536. for (i = 0; i < BL_CODES; i++)
  537. bl_tree[i * 2] = 0;
  538. dyn_ltree[END_BLOCK * 2] = 1;
  539. that.opt_len = that.static_len = 0;
  540. last_lit = matches = 0;
  541. }
  542. // Initialize the tree data structures for a new zlib stream.
  543. function tr_init() {
  544. l_desc.dyn_tree = dyn_ltree;
  545. l_desc.stat_desc = StaticTree.static_l_desc;
  546. d_desc.dyn_tree = dyn_dtree;
  547. d_desc.stat_desc = StaticTree.static_d_desc;
  548. bl_desc.dyn_tree = bl_tree;
  549. bl_desc.stat_desc = StaticTree.static_bl_desc;
  550. bi_buf = 0;
  551. bi_valid = 0;
  552. last_eob_len = 8; // enough lookahead for inflate
  553. // Initialize the first block of the first file:
  554. init_block();
  555. }
  556. // Restore the heap property by moving down the tree starting at node k,
  557. // exchanging a node with the smallest of its two sons if necessary,
  558. // stopping
  559. // when the heap property is re-established (each father smaller than its
  560. // two sons).
  561. that.pqdownheap = function(tree, // the tree to restore
  562. k // node to move down
  563. ) {
  564. var heap = that.heap;
  565. var v = heap[k];
  566. var j = k << 1; // left son of k
  567. while (j <= that.heap_len) {
  568. // Set j to the smallest of the two sons:
  569. if (j < that.heap_len && smaller(tree, heap[j + 1], heap[j], that.depth)) {
  570. j++;
  571. }
  572. // Exit if v is smaller than both sons
  573. if (smaller(tree, v, heap[j], that.depth))
  574. break;
  575. // Exchange v with the smallest son
  576. heap[k] = heap[j];
  577. k = j;
  578. // And continue down the tree, setting j to the left son of k
  579. j <<= 1;
  580. }
  581. heap[k] = v;
  582. };
  583. // Scan a literal or distance tree to determine the frequencies of the codes
  584. // in the bit length tree.
  585. function scan_tree(tree,// the tree to be scanned
  586. max_code // and its largest code of non zero frequency
  587. ) {
  588. var n; // iterates over all tree elements
  589. var prevlen = -1; // last emitted length
  590. var curlen; // length of current code
  591. var nextlen = tree[0 * 2 + 1]; // length of next code
  592. var count = 0; // repeat count of the current code
  593. var max_count = 7; // max repeat count
  594. var min_count = 4; // min repeat count
  595. if (nextlen === 0) {
  596. max_count = 138;
  597. min_count = 3;
  598. }
  599. tree[(max_code + 1) * 2 + 1] = 0xffff; // guard
  600. for (n = 0; n <= max_code; n++) {
  601. curlen = nextlen;
  602. nextlen = tree[(n + 1) * 2 + 1];
  603. if (++count < max_count && curlen == nextlen) {
  604. continue;
  605. } else if (count < min_count) {
  606. bl_tree[curlen * 2] += count;
  607. } else if (curlen !== 0) {
  608. if (curlen != prevlen)
  609. bl_tree[curlen * 2]++;
  610. bl_tree[REP_3_6 * 2]++;
  611. } else if (count <= 10) {
  612. bl_tree[REPZ_3_10 * 2]++;
  613. } else {
  614. bl_tree[REPZ_11_138 * 2]++;
  615. }
  616. count = 0;
  617. prevlen = curlen;
  618. if (nextlen === 0) {
  619. max_count = 138;
  620. min_count = 3;
  621. } else if (curlen == nextlen) {
  622. max_count = 6;
  623. min_count = 3;
  624. } else {
  625. max_count = 7;
  626. min_count = 4;
  627. }
  628. }
  629. }
  630. // Construct the Huffman tree for the bit lengths and return the index in
  631. // bl_order of the last bit length code to send.
  632. function build_bl_tree() {
  633. var max_blindex; // index of last bit length code of non zero freq
  634. // Determine the bit length frequencies for literal and distance trees
  635. scan_tree(dyn_ltree, l_desc.max_code);
  636. scan_tree(dyn_dtree, d_desc.max_code);
  637. // Build the bit length tree:
  638. bl_desc.build_tree(that);
  639. // opt_len now includes the length of the tree representations, except
  640. // the lengths of the bit lengths codes and the 5+5+4 bits for the
  641. // counts.
  642. // Determine the number of bit length codes to send. The pkzip format
  643. // requires that at least 4 bit length codes be sent. (appnote.txt says
  644. // 3 but the actual value used is 4.)
  645. for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--) {
  646. if (bl_tree[Tree.bl_order[max_blindex] * 2 + 1] !== 0)
  647. break;
  648. }
  649. // Update opt_len to include the bit length tree and counts
  650. that.opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
  651. return max_blindex;
  652. }
  653. // Output a byte on the stream.
  654. // IN assertion: there is enough room in pending_buf.
  655. function put_byte(p) {
  656. that.pending_buf[that.pending++] = p;
  657. }
  658. function put_short(w) {
  659. put_byte(w & 0xff);
  660. put_byte((w >>> 8) & 0xff);
  661. }
  662. function putShortMSB(b) {
  663. put_byte((b >> 8) & 0xff);
  664. put_byte((b & 0xff) & 0xff);
  665. }
  666. function send_bits(value, length) {
  667. var val, len = length;
  668. if (bi_valid > Buf_size - len) {
  669. val = value;
  670. // bi_buf |= (val << bi_valid);
  671. bi_buf |= ((val << bi_valid) & 0xffff);
  672. put_short(bi_buf);
  673. bi_buf = val >>> (Buf_size - bi_valid);
  674. bi_valid += len - Buf_size;
  675. } else {
  676. // bi_buf |= (value) << bi_valid;
  677. bi_buf |= (((value) << bi_valid) & 0xffff);
  678. bi_valid += len;
  679. }
  680. }
  681. function send_code(c, tree) {
  682. var c2 = c * 2;
  683. send_bits(tree[c2] & 0xffff, tree[c2 + 1] & 0xffff);
  684. }
  685. // Send a literal or distance tree in compressed form, using the codes in
  686. // bl_tree.
  687. function send_tree(tree,// the tree to be sent
  688. max_code // and its largest code of non zero frequency
  689. ) {
  690. var n; // iterates over all tree elements
  691. var prevlen = -1; // last emitted length
  692. var curlen; // length of current code
  693. var nextlen = tree[0 * 2 + 1]; // length of next code
  694. var count = 0; // repeat count of the current code
  695. var max_count = 7; // max repeat count
  696. var min_count = 4; // min repeat count
  697. if (nextlen === 0) {
  698. max_count = 138;
  699. min_count = 3;
  700. }
  701. for (n = 0; n <= max_code; n++) {
  702. curlen = nextlen;
  703. nextlen = tree[(n + 1) * 2 + 1];
  704. if (++count < max_count && curlen == nextlen) {
  705. continue;
  706. } else if (count < min_count) {
  707. do {
  708. send_code(curlen, bl_tree);
  709. } while (--count !== 0);
  710. } else if (curlen !== 0) {
  711. if (curlen != prevlen) {
  712. send_code(curlen, bl_tree);
  713. count--;
  714. }
  715. send_code(REP_3_6, bl_tree);
  716. send_bits(count - 3, 2);
  717. } else if (count <= 10) {
  718. send_code(REPZ_3_10, bl_tree);
  719. send_bits(count - 3, 3);
  720. } else {
  721. send_code(REPZ_11_138, bl_tree);
  722. send_bits(count - 11, 7);
  723. }
  724. count = 0;
  725. prevlen = curlen;
  726. if (nextlen === 0) {
  727. max_count = 138;
  728. min_count = 3;
  729. } else if (curlen == nextlen) {
  730. max_count = 6;
  731. min_count = 3;
  732. } else {
  733. max_count = 7;
  734. min_count = 4;
  735. }
  736. }
  737. }
  738. // Send the header for a block using dynamic Huffman trees: the counts, the
  739. // lengths of the bit length codes, the literal tree and the distance tree.
  740. // IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
  741. function send_all_trees(lcodes, dcodes, blcodes) {
  742. var rank; // index in bl_order
  743. send_bits(lcodes - 257, 5); // not +255 as stated in appnote.txt
  744. send_bits(dcodes - 1, 5);
  745. send_bits(blcodes - 4, 4); // not -3 as stated in appnote.txt
  746. for (rank = 0; rank < blcodes; rank++) {
  747. send_bits(bl_tree[Tree.bl_order[rank] * 2 + 1], 3);
  748. }
  749. send_tree(dyn_ltree, lcodes - 1); // literal tree
  750. send_tree(dyn_dtree, dcodes - 1); // distance tree
  751. }
  752. // Flush the bit buffer, keeping at most 7 bits in it.
  753. function bi_flush() {
  754. if (bi_valid == 16) {
  755. put_short(bi_buf);
  756. bi_buf = 0;
  757. bi_valid = 0;
  758. } else if (bi_valid >= 8) {
  759. put_byte(bi_buf & 0xff);
  760. bi_buf >>>= 8;
  761. bi_valid -= 8;
  762. }
  763. }
  764. // Send one empty static block to give enough lookahead for inflate.
  765. // This takes 10 bits, of which 7 may remain in the bit buffer.
  766. // The current inflate code requires 9 bits of lookahead. If the
  767. // last two codes for the previous block (real code plus EOB) were coded
  768. // on 5 bits or less, inflate may have only 5+3 bits of lookahead to decode
  769. // the last real code. In this case we send two empty static blocks instead
  770. // of one. (There are no problems if the previous block is stored or fixed.)
  771. // To simplify the code, we assume the worst case of last real code encoded
  772. // on one bit only.
  773. function _tr_align() {
  774. send_bits(STATIC_TREES << 1, 3);
  775. send_code(END_BLOCK, StaticTree.static_ltree);
  776. bi_flush();
  777. // Of the 10 bits for the empty block, we have already sent
  778. // (10 - bi_valid) bits. The lookahead for the last real code (before
  779. // the EOB of the previous block) was thus at least one plus the length
  780. // of the EOB plus what we have just sent of the empty static block.
  781. if (1 + last_eob_len + 10 - bi_valid < 9) {
  782. send_bits(STATIC_TREES << 1, 3);
  783. send_code(END_BLOCK, StaticTree.static_ltree);
  784. bi_flush();
  785. }
  786. last_eob_len = 7;
  787. }
  788. // Save the match info and tally the frequency counts. Return true if
  789. // the current block must be flushed.
  790. function _tr_tally(dist, // distance of matched string
  791. lc // match length-MIN_MATCH or unmatched char (if dist==0)
  792. ) {
  793. var out_length, in_length, dcode;
  794. that.pending_buf[d_buf + last_lit * 2] = (dist >>> 8) & 0xff;
  795. that.pending_buf[d_buf + last_lit * 2 + 1] = dist & 0xff;
  796. that.pending_buf[l_buf + last_lit] = lc & 0xff;
  797. last_lit++;
  798. if (dist === 0) {
  799. // lc is the unmatched char
  800. dyn_ltree[lc * 2]++;
  801. } else {
  802. matches++;
  803. // Here, lc is the match length - MIN_MATCH
  804. dist--; // dist = match distance - 1
  805. dyn_ltree[(Tree._length_code[lc] + LITERALS + 1) * 2]++;
  806. dyn_dtree[Tree.d_code(dist) * 2]++;
  807. }
  808. if ((last_lit & 0x1fff) === 0 && level > 2) {
  809. // Compute an upper bound for the compressed length
  810. out_length = last_lit * 8;
  811. in_length = strstart - block_start;
  812. for (dcode = 0; dcode < D_CODES; dcode++) {
  813. out_length += dyn_dtree[dcode * 2] * (5 + Tree.extra_dbits[dcode]);
  814. }
  815. out_length >>>= 3;
  816. if ((matches < Math.floor(last_lit / 2)) && out_length < Math.floor(in_length / 2))
  817. return true;
  818. }
  819. return (last_lit == lit_bufsize - 1);
  820. // We avoid equality with lit_bufsize because of wraparound at 64K
  821. // on 16 bit machines and because stored blocks are restricted to
  822. // 64K-1 bytes.
  823. }
  824. // Send the block data compressed using the given Huffman trees
  825. function compress_block(ltree, dtree) {
  826. var dist; // distance of matched string
  827. var lc; // match length or unmatched char (if dist === 0)
  828. var lx = 0; // running index in l_buf
  829. var code; // the code to send
  830. var extra; // number of extra bits to send
  831. if (last_lit !== 0) {
  832. do {
  833. dist = ((that.pending_buf[d_buf + lx * 2] << 8) & 0xff00) | (that.pending_buf[d_buf + lx * 2 + 1] & 0xff);
  834. lc = (that.pending_buf[l_buf + lx]) & 0xff;
  835. lx++;
  836. if (dist === 0) {
  837. send_code(lc, ltree); // send a literal byte
  838. } else {
  839. // Here, lc is the match length - MIN_MATCH
  840. code = Tree._length_code[lc];
  841. send_code(code + LITERALS + 1, ltree); // send the length
  842. // code
  843. extra = Tree.extra_lbits[code];
  844. if (extra !== 0) {
  845. lc -= Tree.base_length[code];
  846. send_bits(lc, extra); // send the extra length bits
  847. }
  848. dist--; // dist is now the match distance - 1
  849. code = Tree.d_code(dist);
  850. send_code(code, dtree); // send the distance code
  851. extra = Tree.extra_dbits[code];
  852. if (extra !== 0) {
  853. dist -= Tree.base_dist[code];
  854. send_bits(dist, extra); // send the extra distance bits
  855. }
  856. } // literal or match pair ?
  857. // Check that the overlay between pending_buf and d_buf+l_buf is
  858. // ok:
  859. } while (lx < last_lit);
  860. }
  861. send_code(END_BLOCK, ltree);
  862. last_eob_len = ltree[END_BLOCK * 2 + 1];
  863. }
  864. // Flush the bit buffer and align the output on a byte boundary
  865. function bi_windup() {
  866. if (bi_valid > 8) {
  867. put_short(bi_buf);
  868. } else if (bi_valid > 0) {
  869. put_byte(bi_buf & 0xff);
  870. }
  871. bi_buf = 0;
  872. bi_valid = 0;
  873. }
  874. // Copy a stored block, storing first the length and its
  875. // one's complement if requested.
  876. function copy_block(buf, // the input data
  877. len, // its length
  878. header // true if block header must be written
  879. ) {
  880. bi_windup(); // align on byte boundary
  881. last_eob_len = 8; // enough lookahead for inflate
  882. if (header) {
  883. put_short(len);
  884. put_short(~len);
  885. }
  886. that.pending_buf.set(window.subarray(buf, buf + len), that.pending);
  887. that.pending += len;
  888. }
  889. // Send a stored block
  890. function _tr_stored_block(buf, // input block
  891. stored_len, // length of input block
  892. eof // true if this is the last block for a file
  893. ) {
  894. send_bits((STORED_BLOCK << 1) + (eof ? 1 : 0), 3); // send block type
  895. copy_block(buf, stored_len, true); // with header
  896. }
  897. // Determine the best encoding for the current block: dynamic trees, static
  898. // trees or store, and output the encoded block to the zip file.
  899. function _tr_flush_block(buf, // input block, or NULL if too old
  900. stored_len, // length of input block
  901. eof // true if this is the last block for a file
  902. ) {
  903. var opt_lenb, static_lenb;// opt_len and static_len in bytes
  904. var max_blindex = 0; // index of last bit length code of non zero freq
  905. // Build the Huffman trees unless a stored block is forced
  906. if (level > 0) {
  907. // Construct the literal and distance trees
  908. l_desc.build_tree(that);
  909. d_desc.build_tree(that);
  910. // At this point, opt_len and static_len are the total bit lengths
  911. // of
  912. // the compressed block data, excluding the tree representations.
  913. // Build the bit length tree for the above two trees, and get the
  914. // index
  915. // in bl_order of the last bit length code to send.
  916. max_blindex = build_bl_tree();
  917. // Determine the best encoding. Compute first the block length in
  918. // bytes
  919. opt_lenb = (that.opt_len + 3 + 7) >>> 3;
  920. static_lenb = (that.static_len + 3 + 7) >>> 3;
  921. if (static_lenb <= opt_lenb)
  922. opt_lenb = static_lenb;
  923. } else {
  924. opt_lenb = static_lenb = stored_len + 5; // force a stored block
  925. }
  926. if ((stored_len + 4 <= opt_lenb) && buf != -1) {
  927. // 4: two words for the lengths
  928. // The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
  929. // Otherwise we can't have processed more than WSIZE input bytes
  930. // since
  931. // the last block flush, because compression would have been
  932. // successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
  933. // transform a block into a stored block.
  934. _tr_stored_block(buf, stored_len, eof);
  935. } else if (static_lenb == opt_lenb) {
  936. send_bits((STATIC_TREES << 1) + (eof ? 1 : 0), 3);
  937. compress_block(StaticTree.static_ltree, StaticTree.static_dtree);
  938. } else {
  939. send_bits((DYN_TREES << 1) + (eof ? 1 : 0), 3);
  940. send_all_trees(l_desc.max_code + 1, d_desc.max_code + 1, max_blindex + 1);
  941. compress_block(dyn_ltree, dyn_dtree);
  942. }
  943. // The above check is made mod 2^32, for files larger than 512 MB
  944. // and uLong implemented on 32 bits.
  945. init_block();
  946. if (eof) {
  947. bi_windup();
  948. }
  949. }
  950. function flush_block_only(eof) {
  951. _tr_flush_block(block_start >= 0 ? block_start : -1, strstart - block_start, eof);
  952. block_start = strstart;
  953. strm.flush_pending();
  954. }
  955. // Fill the window when the lookahead becomes insufficient.
  956. // Updates strstart and lookahead.
  957. //
  958. // IN assertion: lookahead < MIN_LOOKAHEAD
  959. // OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
  960. // At least one byte has been read, or avail_in === 0; reads are
  961. // performed for at least two bytes (required for the zip translate_eol
  962. // option -- not supported here).
  963. function fill_window() {
  964. var n, m;
  965. var p;
  966. var more; // Amount of free space at the end of the window.
  967. do {
  968. more = (window_size - lookahead - strstart);
  969. // Deal with !@#$% 64K limit:
  970. if (more === 0 && strstart === 0 && lookahead === 0) {
  971. more = w_size;
  972. } else if (more == -1) {
  973. // Very unlikely, but possible on 16 bit machine if strstart ==
  974. // 0
  975. // and lookahead == 1 (input done one byte at time)
  976. more--;
  977. // If the window is almost full and there is insufficient
  978. // lookahead,
  979. // move the upper half to the lower one to make room in the
  980. // upper half.
  981. } else if (strstart >= w_size + w_size - MIN_LOOKAHEAD) {
  982. window.set(window.subarray(w_size, w_size + w_size), 0);
  983. match_start -= w_size;
  984. strstart -= w_size; // we now have strstart >= MAX_DIST
  985. block_start -= w_size;
  986. // Slide the hash table (could be avoided with 32 bit values
  987. // at the expense of memory usage). We slide even when level ==
  988. // 0
  989. // to keep the hash table consistent if we switch back to level
  990. // > 0
  991. // later. (Using level 0 permanently is not an optimal usage of
  992. // zlib, so we don't care about this pathological case.)
  993. n = hash_size;
  994. p = n;
  995. do {
  996. m = (head[--p] & 0xffff);
  997. head[p] = (m >= w_size ? m - w_size : 0);
  998. } while (--n !== 0);
  999. n = w_size;
  1000. p = n;
  1001. do {
  1002. m = (prev[--p] & 0xffff);
  1003. prev[p] = (m >= w_size ? m - w_size : 0);
  1004. // If n is not on any hash chain, prev[n] is garbage but
  1005. // its value will never be used.
  1006. } while (--n !== 0);
  1007. more += w_size;
  1008. }
  1009. if (strm.avail_in === 0)
  1010. return;
  1011. // If there was no sliding:
  1012. // strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
  1013. // more == window_size - lookahead - strstart
  1014. // => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
  1015. // => more >= window_size - 2*WSIZE + 2
  1016. // In the BIG_MEM or MMAP case (not yet supported),
  1017. // window_size == input_size + MIN_LOOKAHEAD &&
  1018. // strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
  1019. // Otherwise, window_size == 2*WSIZE so more >= 2.
  1020. // If there was sliding, more >= WSIZE. So in all cases, more >= 2.
  1021. n = strm.read_buf(window, strstart + lookahead, more);
  1022. lookahead += n;
  1023. // Initialize the hash value now that we have some input:
  1024. if (lookahead >= MIN_MATCH) {
  1025. ins_h = window[strstart] & 0xff;
  1026. ins_h = (((ins_h) << hash_shift) ^ (window[strstart + 1] & 0xff)) & hash_mask;
  1027. }
  1028. // If the whole input has less than MIN_MATCH bytes, ins_h is
  1029. // garbage,
  1030. // but this is not important since only literal bytes will be
  1031. // emitted.
  1032. } while (lookahead < MIN_LOOKAHEAD && strm.avail_in !== 0);
  1033. }
  1034. // Copy without compression as much as possible from the input stream,
  1035. // return
  1036. // the current block state.
  1037. // This function does not insert new strings in the dictionary since
  1038. // uncompressible data is probably not useful. This function is used
  1039. // only for the level=0 compression option.
  1040. // NOTE: this function should be optimized to avoid extra copying from
  1041. // window to pending_buf.
  1042. function deflate_stored(flush) {
  1043. // Stored blocks are limited to 0xffff bytes, pending_buf is limited
  1044. // to pending_buf_size, and each stored block has a 5 byte header:
  1045. var max_block_size = 0xffff;
  1046. var max_start;
  1047. if (max_block_size > pending_buf_size - 5) {
  1048. max_block_size = pending_buf_size - 5;
  1049. }
  1050. // Copy as much as possible from input to output:
  1051. while (true) {
  1052. // Fill the window as much as possible:
  1053. if (lookahead <= 1) {
  1054. fill_window();
  1055. if (lookahead === 0 && flush == Z_NO_FLUSH)
  1056. return NeedMore;
  1057. if (lookahead === 0)
  1058. break; // flush the current block
  1059. }
  1060. strstart += lookahead;
  1061. lookahead = 0;
  1062. // Emit a stored block if pending_buf will be full:
  1063. max_start = block_start + max_block_size;
  1064. if (strstart === 0 || strstart >= max_start) {
  1065. // strstart === 0 is possible when wraparound on 16-bit machine
  1066. lookahead = (strstart - max_start);
  1067. strstart = max_start;
  1068. flush_block_only(false);
  1069. if (strm.avail_out === 0)
  1070. return NeedMore;
  1071. }
  1072. // Flush if we may have to slide, otherwise block_start may become
  1073. // negative and the data will be gone:
  1074. if (strstart - block_start >= w_size - MIN_LOOKAHEAD) {
  1075. flush_block_only(false);
  1076. if (strm.avail_out === 0)
  1077. return NeedMore;
  1078. }
  1079. }
  1080. flush_block_only(flush == Z_FINISH);
  1081. if (strm.avail_out === 0)
  1082. return (flush == Z_FINISH) ? FinishStarted : NeedMore;
  1083. return flush == Z_FINISH ? FinishDone : BlockDone;
  1084. }
  1085. function longest_match(cur_match) {
  1086. var chain_length = max_chain_length; // max hash chain length
  1087. var scan = strstart; // current string
  1088. var match; // matched string
  1089. var len; // length of current match
  1090. var best_len = prev_length; // best match length so far
  1091. var limit = strstart > (w_size - MIN_LOOKAHEAD) ? strstart - (w_size - MIN_LOOKAHEAD) : 0;
  1092. var _nice_match = nice_match;
  1093. // Stop when cur_match becomes <= limit. To simplify the code,
  1094. // we prevent matches with the string of window index 0.
  1095. var wmask = w_mask;
  1096. var strend = strstart + MAX_MATCH;
  1097. var scan_end1 = window[scan + best_len - 1];
  1098. var scan_end = window[scan + best_len];
  1099. // The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of
  1100. // 16.
  1101. // It is easy to get rid of this optimization if necessary.
  1102. // Do not waste too much time if we already have a good match:
  1103. if (prev_length >= good_match) {
  1104. chain_length >>= 2;
  1105. }
  1106. // Do not look for matches beyond the end of the input. This is
  1107. // necessary
  1108. // to make deflate deterministic.
  1109. if (_nice_match > lookahead)
  1110. _nice_match = lookahead;
  1111. do {
  1112. match = cur_match;
  1113. // Skip to next match if the match length cannot increase
  1114. // or if the match length is less than 2:
  1115. if (window[match + best_len] != scan_end || window[match + best_len - 1] != scan_end1 || window[match] != window[scan]
  1116. || window[++match] != window[scan + 1])
  1117. continue;
  1118. // The check at best_len-1 can be removed because it will be made
  1119. // again later. (This heuristic is not always a win.)
  1120. // It is not necessary to compare scan[2] and match[2] since they
  1121. // are always equal when the other bytes match, given that
  1122. // the hash keys are equal and that HASH_BITS >= 8.
  1123. scan += 2;
  1124. match++;
  1125. // We check for insufficient lookahead only every 8th comparison;
  1126. // the 256th check will be made at strstart+258.
  1127. do {
  1128. } while (window[++scan] == window[++match] && window[++scan] == window[++match] && window[++scan] == window[++match]
  1129. && window[++scan] == window[++match] && window[++scan] == window[++match] && window[++scan] == window[++match]
  1130. && window[++scan] == window[++match] && window[++scan] == window[++match] && scan < strend);
  1131. len = MAX_MATCH - (strend - scan);
  1132. scan = strend - MAX_MATCH;
  1133. if (len > best_len) {
  1134. match_start = cur_match;
  1135. best_len = len;
  1136. if (len >= _nice_match)
  1137. break;
  1138. scan_end1 = window[scan + best_len - 1];
  1139. scan_end = window[scan + best_len];
  1140. }
  1141. } while ((cur_match = (prev[cur_match & wmask] & 0xffff)) > limit && --chain_length !== 0);
  1142. if (best_len <= lookahead)
  1143. return best_len;
  1144. return lookahead;
  1145. }
  1146. // Compress as much as possible from the input stream, return the current
  1147. // block state.
  1148. // This function does not perform lazy evaluation of matches and inserts
  1149. // new strings in the dictionary only for unmatched strings or for short
  1150. // matches. It is used only for the fast compression options.
  1151. function deflate_fast(flush) {
  1152. // short hash_head = 0; // head of the hash chain
  1153. var hash_head = 0; // head of the hash chain
  1154. var bflush; // set if current block must be flushed
  1155. while (true) {
  1156. // Make sure that we always have enough lookahead, except
  1157. // at the end of the input file. We need MAX_MATCH bytes
  1158. // for the next match, plus MIN_MATCH bytes to insert the
  1159. // string following the next match.
  1160. if (lookahead < MIN_LOOKAHEAD) {
  1161. fill_window();
  1162. if (lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
  1163. return NeedMore;
  1164. }
  1165. if (lookahead === 0)
  1166. break; // flush the current block
  1167. }
  1168. // Insert the string window[strstart .. strstart+2] in the
  1169. // dictionary, and set hash_head to the head of the hash chain:
  1170. if (lookahead >= MIN_MATCH) {
  1171. ins_h = (((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
  1172. // prev[strstart&w_mask]=hash_head=head[ins_h];
  1173. hash_head = (head[ins_h] & 0xffff);
  1174. prev[strstart & w_mask] = head[ins_h];
  1175. head[ins_h] = strstart;
  1176. }
  1177. // Find the longest match, discarding those <= prev_length.
  1178. // At this point we have always match_length < MIN_MATCH
  1179. if (hash_head !== 0 && ((strstart - hash_head) & 0xffff) <= w_size - MIN_LOOKAHEAD) {
  1180. // To simplify the code, we prevent matches with the string
  1181. // of window index 0 (in particular we have to avoid a match
  1182. // of the string with itself at the start of the input file).
  1183. if (strategy != Z_HUFFMAN_ONLY) {
  1184. match_length = longest_match(hash_head);
  1185. }
  1186. // longest_match() sets match_start
  1187. }
  1188. if (match_length >= MIN_MATCH) {
  1189. // check_match(strstart, match_start, match_length);
  1190. bflush = _tr_tally(strstart - match_start, match_length - MIN_MATCH);
  1191. lookahead -= match_length;
  1192. // Insert new strings in the hash table only if the match length
  1193. // is not too large. This saves time but degrades compression.
  1194. if (match_length <= max_lazy_match && lookahead >= MIN_MATCH) {
  1195. match_length--; // string at strstart already in hash table
  1196. do {
  1197. strstart++;
  1198. ins_h = ((ins_h << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
  1199. // prev[strstart&w_mask]=hash_head=head[ins_h];
  1200. hash_head = (head[ins_h] & 0xffff);
  1201. prev[strstart & w_mask] = head[ins_h];
  1202. head[ins_h] = strstart;
  1203. // strstart never exceeds WSIZE-MAX_MATCH, so there are
  1204. // always MIN_MATCH bytes ahead.
  1205. } while (--match_length !== 0);
  1206. strstart++;
  1207. } else {
  1208. strstart += match_length;
  1209. match_length = 0;
  1210. ins_h = window[strstart] & 0xff;
  1211. ins_h = (((ins_h) << hash_shift) ^ (window[strstart + 1] & 0xff)) & hash_mask;
  1212. // If lookahead < MIN_MATCH, ins_h is garbage, but it does
  1213. // not
  1214. // matter since it will be recomputed at next deflate call.
  1215. }
  1216. } else {
  1217. // No match, output a literal byte
  1218. bflush = _tr_tally(0, window[strstart] & 0xff);
  1219. lookahead--;
  1220. strstart++;
  1221. }
  1222. if (bflush) {
  1223. flush_block_only(false);
  1224. if (strm.avail_out === 0)
  1225. return NeedMore;
  1226. }
  1227. }
  1228. flush_block_only(flush == Z_FINISH);
  1229. if (strm.avail_out === 0) {
  1230. if (flush == Z_FINISH)
  1231. return FinishStarted;
  1232. else
  1233. return NeedMore;
  1234. }
  1235. return flush == Z_FINISH ? FinishDone : BlockDone;
  1236. }
  1237. // Same as above, but achieves better compression. We use a lazy
  1238. // evaluation for matches: a match is finally adopted only if there is
  1239. // no better match at the next window position.
  1240. function deflate_slow(flush) {
  1241. // short hash_head = 0; // head of hash chain
  1242. var hash_head = 0; // head of hash chain
  1243. var bflush; // set if current block must be flushed
  1244. var max_insert;
  1245. // Process the input block.
  1246. while (true) {
  1247. // Make sure that we always have enough lookahead, except
  1248. // at the end of the input file. We need MAX_MATCH bytes
  1249. // for the next match, plus MIN_MATCH bytes to insert the
  1250. // string following the next match.
  1251. if (lookahead < MIN_LOOKAHEAD) {
  1252. fill_window();
  1253. if (lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) {
  1254. return NeedMore;
  1255. }
  1256. if (lookahead === 0)
  1257. break; // flush the current block
  1258. }
  1259. // Insert the string window[strstart .. strstart+2] in the
  1260. // dictionary, and set hash_head to the head of the hash chain:
  1261. if (lookahead >= MIN_MATCH) {
  1262. ins_h = (((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
  1263. // prev[strstart&w_mask]=hash_head=head[ins_h];
  1264. hash_head = (head[ins_h] & 0xffff);
  1265. prev[strstart & w_mask] = head[ins_h];
  1266. head[ins_h] = strstart;
  1267. }
  1268. // Find the longest match, discarding those <= prev_length.
  1269. prev_length = match_length;
  1270. prev_match = match_start;
  1271. match_length = MIN_MATCH - 1;
  1272. if (hash_head !== 0 && prev_length < max_lazy_match && ((strstart - hash_head) & 0xffff) <= w_size - MIN_LOOKAHEAD) {
  1273. // To simplify the code, we prevent matches with the string
  1274. // of window index 0 (in particular we have to avoid a match
  1275. // of the string with itself at the start of the input file).
  1276. if (strategy != Z_HUFFMAN_ONLY) {
  1277. match_length = longest_match(hash_head);
  1278. }
  1279. // longest_match() sets match_start
  1280. if (match_length <= 5 && (strategy == Z_FILTERED || (match_length == MIN_MATCH && strstart - match_start > 4096))) {
  1281. // If prev_match is also MIN_MATCH, match_start is garbage
  1282. // but we will ignore the current match anyway.
  1283. match_length = MIN_MATCH - 1;
  1284. }
  1285. }
  1286. // If there was a match at the previous step and the current
  1287. // match is not better, output the previous match:
  1288. if (prev_length >= MIN_MATCH && match_length <= prev_length) {
  1289. max_insert = strstart + lookahead - MIN_MATCH;
  1290. // Do not insert strings in hash table beyond this.
  1291. // check_match(strstart-1, prev_match, prev_length);
  1292. bflush = _tr_tally(strstart - 1 - prev_match, prev_length - MIN_MATCH);
  1293. // Insert in hash table all strings up to the end of the match.
  1294. // strstart-1 and strstart are already inserted. If there is not
  1295. // enough lookahead, the last two strings are not inserted in
  1296. // the hash table.
  1297. lookahead -= prev_length - 1;
  1298. prev_length -= 2;
  1299. do {
  1300. if (++strstart <= max_insert) {
  1301. ins_h = (((ins_h) << hash_shift) ^ (window[(strstart) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
  1302. // prev[strstart&w_mask]=hash_head=head[ins_h];
  1303. hash_head = (head[ins_h] & 0xffff);
  1304. prev[strstart & w_mask] = head[ins_h];
  1305. head[ins_h] = strstart;
  1306. }
  1307. } while (--prev_length !== 0);
  1308. match_available = 0;
  1309. match_length = MIN_MATCH - 1;
  1310. strstart++;
  1311. if (bflush) {
  1312. flush_block_only(false);
  1313. if (strm.avail_out === 0)
  1314. return NeedMore;
  1315. }
  1316. } else if (match_available !== 0) {
  1317. // If there was no match at the previous position, output a
  1318. // single literal. If there was a match but the current match
  1319. // is longer, truncate the previous match to a single literal.
  1320. bflush = _tr_tally(0, window[strstart - 1] & 0xff);
  1321. if (bflush) {
  1322. flush_block_only(false);
  1323. }
  1324. strstart++;
  1325. lookahead--;
  1326. if (strm.avail_out === 0)
  1327. return NeedMore;
  1328. } else {
  1329. // There is no previous match to compare with, wait for
  1330. // the next step to decide.
  1331. match_available = 1;
  1332. strstart++;
  1333. lookahead--;
  1334. }
  1335. }
  1336. if (match_available !== 0) {
  1337. bflush = _tr_tally(0, window[strstart - 1] & 0xff);
  1338. match_available = 0;
  1339. }
  1340. flush_block_only(flush == Z_FINISH);
  1341. if (strm.avail_out === 0) {
  1342. if (flush == Z_FINISH)
  1343. return FinishStarted;
  1344. else
  1345. return NeedMore;
  1346. }
  1347. return flush == Z_FINISH ? FinishDone : BlockDone;
  1348. }
  1349. function deflateReset(strm) {
  1350. strm.total_in = strm.total_out = 0;
  1351. strm.msg = null; //
  1352. that.pending = 0;
  1353. that.pending_out = 0;
  1354. status = BUSY_STATE;
  1355. last_flush = Z_NO_FLUSH;
  1356. tr_init();
  1357. lm_init();
  1358. return Z_OK;
  1359. }
  1360. that.deflateInit = function(strm, _level, bits, _method, memLevel, _strategy) {
  1361. if (!_method)
  1362. _method = Z_DEFLATED;
  1363. if (!memLevel)
  1364. memLevel = DEF_MEM_LEVEL;
  1365. if (!_strategy)
  1366. _strategy = Z_DEFAULT_STRATEGY;
  1367. // byte[] my_version=ZLIB_VERSION;
  1368. //
  1369. // if (!version || version[0] != my_version[0]
  1370. // || stream_size != sizeof(z_stream)) {
  1371. // return Z_VERSION_ERROR;
  1372. // }
  1373. strm.msg = null;
  1374. if (_level == Z_DEFAULT_COMPRESSION)
  1375. _level = 6;
  1376. if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || _method != Z_DEFLATED || bits < 9 || bits > 15 || _level < 0 || _level > 9 || _strategy < 0
  1377. || _strategy > Z_HUFFMAN_ONLY) {
  1378. return Z_STREAM_ERROR;
  1379. }
  1380. strm.dstate = that;
  1381. w_bits = bits;
  1382. w_size = 1 << w_bits;
  1383. w_mask = w_size - 1;
  1384. hash_bits = memLevel + 7;
  1385. hash_size = 1 << hash_bits;
  1386. hash_mask = hash_size - 1;
  1387. hash_shift = Math.floor((hash_bits + MIN_MATCH - 1) / MIN_MATCH);
  1388. window = new Uint8Array(w_size * 2);
  1389. prev = [];
  1390. head = [];
  1391. lit_bufsize = 1 << (memLevel + 6); // 16K elements by default
  1392. // We overlay pending_buf and d_buf+l_buf. This works since the average
  1393. // output size for (length,distance) codes is <= 24 bits.
  1394. that.pending_buf = new Uint8Array(lit_bufsize * 4);
  1395. pending_buf_size = lit_bufsize * 4;
  1396. d_buf = Math.floor(lit_bufsize / 2);
  1397. l_buf = (1 + 2) * lit_bufsize;
  1398. level = _level;
  1399. strategy = _strategy;
  1400. method = _method & 0xff;
  1401. return deflateReset(strm);
  1402. };
  1403. that.deflateEnd = function() {
  1404. if (status != INIT_STATE && status != BUSY_STATE && status != FINISH_STATE) {
  1405. return Z_STREAM_ERROR;
  1406. }
  1407. // Deallocate in reverse order of allocations:
  1408. that.pending_buf = null;
  1409. head = null;
  1410. prev = null;
  1411. window = null;
  1412. // free
  1413. that.dstate = null;
  1414. return status == BUSY_STATE ? Z_DATA_ERROR : Z_OK;
  1415. };
  1416. that.deflateParams = function(strm, _level, _strategy) {
  1417. var err = Z_OK;
  1418. if (_level == Z_DEFAULT_COMPRESSION) {
  1419. _level = 6;
  1420. }
  1421. if (_level < 0 || _level > 9 || _strategy < 0 || _strategy > Z_HUFFMAN_ONLY) {
  1422. return Z_STREAM_ERROR;
  1423. }
  1424. if (config_table[level].func != config_table[_level].func && strm.total_in !== 0) {
  1425. // Flush the last buffer:
  1426. err = strm.deflate(Z_PARTIAL_FLUSH);
  1427. }
  1428. if (level != _level) {
  1429. level = _level;
  1430. max_lazy_match = config_table[level].max_lazy;
  1431. good_match = config_table[level].good_length;
  1432. nice_match = config_table[level].nice_length;
  1433. max_chain_length = config_table[level].max_chain;
  1434. }
  1435. strategy = _strategy;
  1436. return err;
  1437. };
  1438. that.deflateSetDictionary = function(strm, dictionary, dictLength) {
  1439. var length = dictLength;
  1440. var n, index = 0;
  1441. if (!dictionary || status != INIT_STATE)
  1442. return Z_STREAM_ERROR;
  1443. if (length < MIN_MATCH)
  1444. return Z_OK;
  1445. if (length > w_size - MIN_LOOKAHEAD) {
  1446. length = w_size - MIN_LOOKAHEAD;
  1447. index = dictLength - length; // use the tail of the dictionary
  1448. }
  1449. window.set(dictionary.subarray(index, index + length), 0);
  1450. strstart = length;
  1451. block_start = length;
  1452. // Insert all strings in the hash table (except for the last two bytes).
  1453. // s->lookahead stays null, so s->ins_h will be recomputed at the next
  1454. // call of fill_window.
  1455. ins_h = window[0] & 0xff;
  1456. ins_h = (((ins_h) << hash_shift) ^ (window[1] & 0xff)) & hash_mask;
  1457. for (n = 0; n <= length - MIN_MATCH; n++) {
  1458. ins_h = (((ins_h) << hash_shift) ^ (window[(n) + (MIN_MATCH - 1)] & 0xff)) & hash_mask;
  1459. prev[n & w_mask] = head[ins_h];
  1460. head[ins_h] = n;
  1461. }
  1462. return Z_OK;
  1463. };
  1464. that.deflate = function(_strm, flush) {
  1465. var i, header, level_flags, old_flush, bstate;
  1466. if (flush > Z_FINISH || flush < 0) {
  1467. return Z_STREAM_ERROR;
  1468. }
  1469. if (!_strm.next_out || (!_strm.next_in && _strm.avail_in !== 0) || (status == FINISH_STATE && flush != Z_FINISH)) {
  1470. _strm.msg = z_errmsg[Z_NEED_DICT - (Z_STREAM_ERROR)];
  1471. return Z_STREAM_ERROR;
  1472. }
  1473. if (_strm.avail_out === 0) {
  1474. _strm.msg = z_errmsg[Z_NEED_DICT - (Z_BUF_ERROR)];
  1475. return Z_BUF_ERROR;
  1476. }
  1477. strm = _strm; // just in case
  1478. old_flush = last_flush;
  1479. last_flush = flush;
  1480. // Write the zlib header
  1481. if (status == INIT_STATE) {
  1482. header = (Z_DEFLATED + ((w_bits - 8) << 4)) << 8;
  1483. level_flags = ((level - 1) & 0xff) >> 1;
  1484. if (level_flags > 3)
  1485. level_flags = 3;
  1486. header |= (level_flags << 6);
  1487. if (strstart !== 0)
  1488. header |= PRESET_DICT;
  1489. header += 31 - (header % 31);
  1490. status = BUSY_STATE;
  1491. putShortMSB(header);
  1492. }
  1493. // Flush as much pending output as possible
  1494. if (that.pending !== 0) {
  1495. strm.flush_pending();
  1496. if (strm.avail_out === 0) {
  1497. // console.log(" avail_out==0");
  1498. // Since avail_out is 0, deflate will be called again with
  1499. // more output space, but possibly with both pending and
  1500. // avail_in equal to zero. There won't be anything to do,
  1501. // but this is not an error situation so make sure we
  1502. // return OK instead of BUF_ERROR at next call of deflate:
  1503. last_flush = -1;
  1504. return Z_OK;
  1505. }
  1506. // Make sure there is something to do and avoid duplicate
  1507. // consecutive
  1508. // flushes. For repeated and useless calls with Z_FINISH, we keep
  1509. // returning Z_STREAM_END instead of Z_BUFF_ERROR.
  1510. } else if (strm.avail_in === 0 && flush <= old_flush && flush != Z_FINISH) {
  1511. strm.msg = z_errmsg[Z_NEED_DICT - (Z_BUF_ERROR)];
  1512. return Z_BUF_ERROR;
  1513. }
  1514. // User must not provide more input after the first FINISH:
  1515. if (status == FINISH_STATE && strm.avail_in !== 0) {
  1516. _strm.msg = z_errmsg[Z_NEED_DICT - (Z_BUF_ERROR)];
  1517. return Z_BUF_ERROR;
  1518. }
  1519. // Start a new block or continue the current one.
  1520. if (strm.avail_in !== 0 || lookahead !== 0 || (flush != Z_NO_FLUSH && status != FINISH_STATE)) {
  1521. bstate = -1;
  1522. switch (config_table[level].func) {
  1523. case STORED:
  1524. bstate = deflate_stored(flush);
  1525. break;
  1526. case FAST:
  1527. bstate = deflate_fast(flush);
  1528. break;
  1529. case SLOW:
  1530. bstate = deflate_slow(flush);
  1531. break;
  1532. default:
  1533. }
  1534. if (bstate == FinishStarted || bstate == FinishDone) {
  1535. status = FINISH_STATE;
  1536. }
  1537. if (bstate == NeedMore || bstate == FinishStarted) {
  1538. if (strm.avail_out === 0) {
  1539. last_flush = -1; // avoid BUF_ERROR next call, see above
  1540. }
  1541. return Z_OK;
  1542. // If flush != Z_NO_FLUSH && avail_out === 0, the next call
  1543. // of deflate should use the same flush parameter to make sure
  1544. // that the flush is complete. So we don't have to output an
  1545. // empty block here, this will be done at next call. This also
  1546. // ensures that for a very small output buffer, we emit at most
  1547. // one empty block.
  1548. }
  1549. if (bstate == BlockDone) {
  1550. if (flush == Z_PARTIAL_FLUSH) {
  1551. _tr_align();
  1552. } else { // FULL_FLUSH or SYNC_FLUSH
  1553. _tr_stored_block(0, 0, false);
  1554. // For a full flush, this empty block will be recognized
  1555. // as a special marker by inflate_sync().
  1556. if (flush == Z_FULL_FLUSH) {
  1557. // state.head[s.hash_size-1]=0;
  1558. for (i = 0; i < hash_size/*-1*/; i++)
  1559. // forget history
  1560. head[i] = 0;
  1561. }
  1562. }
  1563. strm.flush_pending();
  1564. if (strm.avail_out === 0) {
  1565. last_flush = -1; // avoid BUF_ERROR at next call, see above
  1566. return Z_OK;
  1567. }
  1568. }
  1569. }
  1570. if (flush != Z_FINISH)
  1571. return Z_OK;
  1572. return Z_STREAM_END;
  1573. };
  1574. }
  1575. // ZStream
  1576. function ZStream() {
  1577. var that = this;
  1578. that.next_in_index = 0;
  1579. that.next_out_index = 0;
  1580. // that.next_in; // next input byte
  1581. that.avail_in = 0; // number of bytes available at next_in
  1582. that.total_in = 0; // total nb of input bytes read so far
  1583. // that.next_out; // next output byte should be put there
  1584. that.avail_out = 0; // remaining free space at next_out
  1585. that.total_out = 0; // total nb of bytes output so far
  1586. // that.msg;
  1587. // that.dstate;
  1588. }
  1589. ZStream.prototype = {
  1590. deflateInit : function(level, bits) {
  1591. var that = this;
  1592. that.dstate = new Deflate();
  1593. if (!bits)
  1594. bits = MAX_BITS;
  1595. return that.dstate.deflateInit(that, level, bits);
  1596. },
  1597. deflate : function(flush) {
  1598. var that = this;
  1599. if (!that.dstate) {
  1600. return Z_STREAM_ERROR;
  1601. }
  1602. return that.dstate.deflate(that, flush);
  1603. },
  1604. deflateEnd : function() {
  1605. var that = this;
  1606. if (!that.dstate)
  1607. return Z_STREAM_ERROR;
  1608. var ret = that.dstate.deflateEnd();
  1609. that.dstate = null;
  1610. return ret;
  1611. },
  1612. deflateParams : function(level, strategy) {
  1613. var that = this;
  1614. if (!that.dstate)
  1615. return Z_STREAM_ERROR;
  1616. return that.dstate.deflateParams(that, level, strategy);
  1617. },
  1618. deflateSetDictionary : function(dictionary, dictLength) {
  1619. var that = this;
  1620. if (!that.dstate)
  1621. return Z_STREAM_ERROR;
  1622. return that.dstate.deflateSetDictionary(that, dictionary, dictLength);
  1623. },
  1624. // Read a new buffer from the current input stream, update the
  1625. // total number of bytes read. All deflate() input goes through
  1626. // this function so some applications may wish to modify it to avoid
  1627. // allocating a large strm->next_in buffer and copying from it.
  1628. // (See also flush_pending()).
  1629. read_buf : function(buf, start, size) {
  1630. var that = this;
  1631. var len = that.avail_in;
  1632. if (len > size)
  1633. len = size;
  1634. if (len === 0)
  1635. return 0;
  1636. that.avail_in -= len;
  1637. buf.set(that.next_in.subarray(that.next_in_index, that.next_in_index + len), start);
  1638. that.next_in_index += len;
  1639. that.total_in += len;
  1640. return len;
  1641. },
  1642. // Flush as much pending output as possible. All deflate() output goes
  1643. // through this function so some applications may wish to modify it
  1644. // to avoid allocating a large strm->next_out buffer and copying into it.
  1645. // (See also read_buf()).
  1646. flush_pending : function() {
  1647. var that = this;
  1648. var len = that.dstate.pending;
  1649. if (len > that.avail_out)
  1650. len = that.avail_out;
  1651. if (len === 0)
  1652. return;
  1653. // if (that.dstate.pending_buf.length <= that.dstate.pending_out || that.next_out.length <= that.next_out_index
  1654. // || that.dstate.pending_buf.length < (that.dstate.pending_out + len) || that.next_out.length < (that.next_out_index +
  1655. // len)) {
  1656. // console.log(that.dstate.pending_buf.length + ", " + that.dstate.pending_out + ", " + that.next_out.length + ", " +
  1657. // that.next_out_index + ", " + len);
  1658. // console.log("avail_out=" + that.avail_out);
  1659. // }
  1660. that.next_out.set(that.dstate.pending_buf.subarray(that.dstate.pending_out, that.dstate.pending_out + len), that.next_out_index);
  1661. that.next_out_index += len;
  1662. that.dstate.pending_out += len;
  1663. that.total_out += len;
  1664. that.avail_out -= len;
  1665. that.dstate.pending -= len;
  1666. if (that.dstate.pending === 0) {
  1667. that.dstate.pending_out = 0;
  1668. }
  1669. }
  1670. };
  1671. // Deflater
  1672. function Deflater(options) {
  1673. var that = this;
  1674. var z = new ZStream();
  1675. var bufsize = 512;
  1676. var flush = Z_NO_FLUSH;
  1677. var buf = new Uint8Array(bufsize);
  1678. var level = options ? options.level : Z_DEFAULT_COMPRESSION;
  1679. if (typeof level == "undefined")
  1680. level = Z_DEFAULT_COMPRESSION;
  1681. z.deflateInit(level);
  1682. z.next_out = buf;
  1683. that.append = function(data, onprogress) {
  1684. var err, buffers = [], lastIndex = 0, bufferIndex = 0, bufferSize = 0, array;
  1685. if (!data.length)
  1686. return;
  1687. z.next_in_index = 0;
  1688. z.next_in = data;
  1689. z.avail_in = data.length;
  1690. do {
  1691. z.next_out_index = 0;
  1692. z.avail_out = bufsize;
  1693. err = z.deflate(flush);
  1694. if (err != Z_OK)
  1695. throw new Error("deflating: " + z.msg);
  1696. if (z.next_out_index)
  1697. if (z.next_out_index == bufsize)
  1698. buffers.push(new Uint8Array(buf));
  1699. else
  1700. buffers.push(new Uint8Array(buf.subarray(0, z.next_out_index)));
  1701. bufferSize += z.next_out_index;
  1702. if (onprogress && z.next_in_index > 0 && z.next_in_index != lastIndex) {
  1703. onprogress(z.next_in_index);
  1704. lastIndex = z.next_in_index;
  1705. }
  1706. } while (z.avail_in > 0 || z.avail_out === 0);
  1707. array = new Uint8Array(bufferSize);
  1708. buffers.forEach(function(chunk) {
  1709. array.set(chunk, bufferIndex);
  1710. bufferIndex += chunk.length;
  1711. });
  1712. return array;
  1713. };
  1714. that.flush = function() {
  1715. var err, buffers = [], bufferIndex = 0, bufferSize = 0, array;
  1716. do {
  1717. z.next_out_index = 0;
  1718. z.avail_out = bufsize;
  1719. err = z.deflate(Z_FINISH);
  1720. if (err != Z_STREAM_END && err != Z_OK)
  1721. throw new Error("deflating: " + z.msg);
  1722. if (bufsize - z.avail_out > 0)
  1723. buffers.push(new Uint8Array(buf.subarray(0, z.next_out_index)));
  1724. bufferSize += z.next_out_index;
  1725. } while (z.avail_in > 0 || z.avail_out === 0);
  1726. z.deflateEnd();
  1727. array = new Uint8Array(bufferSize);
  1728. buffers.forEach(function(chunk) {
  1729. array.set(chunk, bufferIndex);
  1730. bufferIndex += chunk.length;
  1731. });
  1732. return array;
  1733. };
  1734. }
  1735. // 'zip' may not be defined in z-worker and some tests
  1736. var env = global.zip || global;
  1737. env.Deflater = env._jzlib_Deflater = Deflater;
  1738. })(this);