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| author | ruki <waruqi@gmail.com> | 2018-11-08 00:38:48 +0800 |
|---|---|---|
| committer | ruki <waruqi@gmail.com> | 2018-11-07 21:53:09 +0800 |
| commit | 26105034da4fcce7ac883c899d781f016559310d (patch) | |
| tree | c459a5dc4e3aa0972d9919033ece511ce76dd129 /node_modules/pako/lib/zlib/crc32.js | |
| parent | 2c77f00f1a7ecb6c8192f9c16d3b2001b254a107 (diff) | |
| download | xmake-docs-26105034da4fcce7ac883c899d781f016559310d.tar.gz xmake-docs-26105034da4fcce7ac883c899d781f016559310d.zip | |
switch to vuepress
Diffstat (limited to 'node_modules/pako/lib/zlib/crc32.js')
| -rw-r--r-- | node_modules/pako/lib/zlib/crc32.js | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/node_modules/pako/lib/zlib/crc32.js b/node_modules/pako/lib/zlib/crc32.js new file mode 100644 index 00000000..6a960924 --- /dev/null +++ b/node_modules/pako/lib/zlib/crc32.js @@ -0,0 +1,59 @@ +'use strict'; + +// Note: we can't get significant speed boost here. +// So write code to minimize size - no pregenerated tables +// and array tools dependencies. + +// (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. + +// Use ordinary array, since untyped makes no boost here +function makeTable() { + var c, table = []; + + for (var n = 0; n < 256; n++) { + c = n; + for (var k = 0; k < 8; k++) { + c = ((c & 1) ? (0xEDB88320 ^ (c >>> 1)) : (c >>> 1)); + } + table[n] = c; + } + + return table; +} + +// Create table on load. Just 255 signed longs. Not a problem. +var crcTable = makeTable(); + + +function crc32(crc, buf, len, pos) { + var t = crcTable, + end = pos + len; + + crc ^= -1; + + for (var i = pos; i < end; i++) { + crc = (crc >>> 8) ^ t[(crc ^ buf[i]) & 0xFF]; + } + + return (crc ^ (-1)); // >>> 0; +} + + +module.exports = crc32; |
