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Diffstat (limited to 'school/node_modules/pako/lib/zlib/inftrees.js')
| -rw-r--r-- | school/node_modules/pako/lib/zlib/inftrees.js | 343 |
1 files changed, 0 insertions, 343 deletions
diff --git a/school/node_modules/pako/lib/zlib/inftrees.js b/school/node_modules/pako/lib/zlib/inftrees.js deleted file mode 100644 index ec4e4e9..0000000 --- a/school/node_modules/pako/lib/zlib/inftrees.js +++ /dev/null @@ -1,343 +0,0 @@ -'use strict'; - -// (C) 1995-2013 Jean-loup Gailly and Mark Adler -// (C) 2014-2017 Vitaly Puzrin and Andrey Tupitsin -// -// This software is provided 'as-is', without any express or implied -// warranty. In no event will the authors be held liable for any damages -// arising from the use of this software. -// -// Permission is granted to anyone to use this software for any purpose, -// including commercial applications, and to alter it and redistribute it -// freely, subject to the following restrictions: -// -// 1. The origin of this software must not be misrepresented; you must not -// claim that you wrote the original software. If you use this software -// in a product, an acknowledgment in the product documentation would be -// appreciated but is not required. -// 2. Altered source versions must be plainly marked as such, and must not be -// misrepresented as being the original software. -// 3. This notice may not be removed or altered from any source distribution. - -var utils = require('../utils/common'); - -var MAXBITS = 15; -var ENOUGH_LENS = 852; -var ENOUGH_DISTS = 592; -//var ENOUGH = (ENOUGH_LENS+ENOUGH_DISTS); - -var CODES = 0; -var LENS = 1; -var DISTS = 2; - -var lbase = [ /* Length codes 257..285 base */ - 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, - 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0 -]; - -var lext = [ /* Length codes 257..285 extra */ - 16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18, - 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 72, 78 -]; - -var dbase = [ /* Distance codes 0..29 base */ - 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, - 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, - 8193, 12289, 16385, 24577, 0, 0 -]; - -var dext = [ /* Distance codes 0..29 extra */ - 16, 16, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, - 23, 23, 24, 24, 25, 25, 26, 26, 27, 27, - 28, 28, 29, 29, 64, 64 -]; - -module.exports = function inflate_table(type, lens, lens_index, codes, table, table_index, work, opts) -{ - var bits = opts.bits; - //here = opts.here; /* table entry for duplication */ - - var len = 0; /* a code's length in bits */ - var sym = 0; /* index of code symbols */ - var min = 0, max = 0; /* minimum and maximum code lengths */ - var root = 0; /* number of index bits for root table */ - var curr = 0; /* number of index bits for current table */ - var drop = 0; /* code bits to drop for sub-table */ - var left = 0; /* number of prefix codes available */ - var used = 0; /* code entries in table used */ - var huff = 0; /* Huffman code */ - var incr; /* for incrementing code, index */ - var fill; /* index for replicating entries */ - var low; /* low bits for current root entry */ - var mask; /* mask for low root bits */ - var next; /* next available space in table */ - var base = null; /* base value table to use */ - var base_index = 0; -// var shoextra; /* extra bits table to use */ - var end; /* use base and extra for symbol > end */ - var count = new utils.Buf16(MAXBITS + 1); //[MAXBITS+1]; /* number of codes of each length */ - var offs = new utils.Buf16(MAXBITS + 1); //[MAXBITS+1]; /* offsets in table for each length */ - var extra = null; - var extra_index = 0; - - var here_bits, here_op, here_val; - - /* - Process a set of code lengths to create a canonical Huffman code. The - code lengths are lens[0..codes-1]. Each length corresponds to the - symbols 0..codes-1. The Huffman code is generated by first sorting the - symbols by length from short to long, and retaining the symbol order - for codes with equal lengths. Then the code starts with all zero bits - for the first code of the shortest length, and the codes are integer - increments for the same length, and zeros are appended as the length - increases. For the deflate format, these bits are stored backwards - from their more natural integer increment ordering, and so when the - decoding tables are built in the large loop below, the integer codes - are incremented backwards. - - This routine assumes, but does not check, that all of the entries in - lens[] are in the range 0..MAXBITS. The caller must assure this. - 1..MAXBITS is interpreted as that code length. zero means that that - symbol does not occur in this code. - - The codes are sorted by computing a count of codes for each length, - creating from that a table of starting indices for each length in the - sorted table, and then entering the symbols in order in the sorted - table. The sorted table is work[], with that space being provided by - the caller. - - The length counts are used for other purposes as well, i.e. finding - the minimum and maximum length codes, determining if there are any - codes at all, checking for a valid set of lengths, and looking ahead - at length counts to determine sub-table sizes when building the - decoding tables. - */ - - /* accumulate lengths for codes (assumes lens[] all in 0..MAXBITS) */ - for (len = 0; len <= MAXBITS; len++) { - count[len] = 0; - } - for (sym = 0; sym < codes; sym++) { - count[lens[lens_index + sym]]++; - } - - /* bound code lengths, force root to be within code lengths */ - root = bits; - for (max = MAXBITS; max >= 1; max--) { - if (count[max] !== 0) { break; } - } - if (root > max) { - root = max; - } - if (max === 0) { /* no symbols to code at all */ - //table.op[opts.table_index] = 64; //here.op = (var char)64; /* invalid code marker */ - //table.bits[opts.table_index] = 1; //here.bits = (var char)1; - //table.val[opts.table_index++] = 0; //here.val = (var short)0; - table[table_index++] = (1 << 24) | (64 << 16) | 0; - - - //table.op[opts.table_index] = 64; - //table.bits[opts.table_index] = 1; - //table.val[opts.table_index++] = 0; - table[table_index++] = (1 << 24) | (64 << 16) | 0; - - opts.bits = 1; - return 0; /* no symbols, but wait for decoding to report error */ - } - for (min = 1; min < max; min++) { - if (count[min] !== 0) { break; } - } - if (root < min) { - root = min; - } - - /* check for an over-subscribed or incomplete set of lengths */ - left = 1; - for (len = 1; len <= MAXBITS; len++) { - left <<= 1; - left -= count[len]; - if (left < 0) { - return -1; - } /* over-subscribed */ - } - if (left > 0 && (type === CODES || max !== 1)) { - return -1; /* incomplete set */ - } - - /* generate offsets into symbol table for each length for sorting */ - offs[1] = 0; - for (len = 1; len < MAXBITS; len++) { - offs[len + 1] = offs[len] + count[len]; - } - - /* sort symbols by length, by symbol order within each length */ - for (sym = 0; sym < codes; sym++) { - if (lens[lens_index + sym] !== 0) { - work[offs[lens[lens_index + sym]]++] = sym; - } - } - - /* - Create and fill in decoding tables. In this loop, the table being - filled is at next and has curr index bits. The code being used is huff - with length len. That code is converted to an index by dropping drop - bits off of the bottom. For codes where len is less than drop + curr, - those top drop + curr - len bits are incremented through all values to - fill the table with replicated entries. - - root is the number of index bits for the root table. When len exceeds - root, sub-tables are created pointed to by the root entry with an index - of the low root bits of huff. This is saved in low to check for when a - new sub-table should be started. drop is zero when the root table is - being filled, and drop is root when sub-tables are being filled. - - When a new sub-table is needed, it is necessary to look ahead in the - code lengths to determine what size sub-table is needed. The length - counts are used for this, and so count[] is decremented as codes are - entered in the tables. - - used keeps track of how many table entries have been allocated from the - provided *table space. It is checked for LENS and DIST tables against - the constants ENOUGH_LENS and ENOUGH_DISTS to guard against changes in - the initial root table size constants. See the comments in inftrees.h - for more information. - - sym increments through all symbols, and the loop terminates when - all codes of length max, i.e. all codes, have been processed. This - routine permits incomplete codes, so another loop after this one fills - in the rest of the decoding tables with invalid code markers. - */ - - /* set up for code type */ - // poor man optimization - use if-else instead of switch, - // to avoid deopts in old v8 - if (type === CODES) { - base = extra = work; /* dummy value--not used */ - end = 19; - - } else if (type === LENS) { - base = lbase; - base_index -= 257; - extra = lext; - extra_index -= 257; - end = 256; - - } else { /* DISTS */ - base = dbase; - extra = dext; - end = -1; - } - - /* initialize opts for loop */ - huff = 0; /* starting code */ - sym = 0; /* starting code symbol */ - len = min; /* starting code length */ - next = table_index; /* current table to fill in */ - curr = root; /* current table index bits */ - drop = 0; /* current bits to drop from code for index */ - low = -1; /* trigger new sub-table when len > root */ - used = 1 << root; /* use root table entries */ - mask = used - 1; /* mask for comparing low */ - - /* check available table space */ - if ((type === LENS && used > ENOUGH_LENS) || - (type === DISTS && used > ENOUGH_DISTS)) { - return 1; - } - - /* process all codes and make table entries */ - for (;;) { - /* create table entry */ - here_bits = len - drop; - if (work[sym] < end) { - here_op = 0; - here_val = work[sym]; - } - else if (work[sym] > end) { - here_op = extra[extra_index + work[sym]]; - here_val = base[base_index + work[sym]]; - } - else { - here_op = 32 + 64; /* end of block */ - here_val = 0; - } - - /* replicate for those indices with low len bits equal to huff */ - incr = 1 << (len - drop); - fill = 1 << curr; - min = fill; /* save offset to next table */ - do { - fill -= incr; - table[next + (huff >> drop) + fill] = (here_bits << 24) | (here_op << 16) | here_val |0; - } while (fill !== 0); - - /* backwards increment the len-bit code huff */ - incr = 1 << (len - 1); - while (huff & incr) { - incr >>= 1; - } - if (incr !== 0) { - huff &= incr - 1; - huff += incr; - } else { - huff = 0; - } - - /* go to next symbol, update count, len */ - sym++; - if (--count[len] === 0) { - if (len === max) { break; } - len = lens[lens_index + work[sym]]; - } - - /* create new sub-table if needed */ - if (len > root && (huff & mask) !== low) { - /* if first time, transition to sub-tables */ - if (drop === 0) { - drop = root; - } - - /* increment past last table */ - next += min; /* here min is 1 << curr */ - - /* determine length of next table */ - curr = len - drop; - left = 1 << curr; - while (curr + drop < max) { - left -= count[curr + drop]; - if (left <= 0) { break; } - curr++; - left <<= 1; - } - - /* check for enough space */ - used += 1 << curr; - if ((type === LENS && used > ENOUGH_LENS) || - (type === DISTS && used > ENOUGH_DISTS)) { - return 1; - } - - /* point entry in root table to sub-table */ - low = huff & mask; - /*table.op[low] = curr; - table.bits[low] = root; - table.val[low] = next - opts.table_index;*/ - table[low] = (root << 24) | (curr << 16) | (next - table_index) |0; - } - } - - /* fill in remaining table entry if code is incomplete (guaranteed to have - at most one remaining entry, since if the code is incomplete, the - maximum code length that was allowed to get this far is one bit) */ - if (huff !== 0) { - //table.op[next + huff] = 64; /* invalid code marker */ - //table.bits[next + huff] = len - drop; - //table.val[next + huff] = 0; - table[next + huff] = ((len - drop) << 24) | (64 << 16) |0; - } - - /* set return parameters */ - //opts.table_index += used; - opts.bits = root; - return 0; -}; |