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/**
* Copyright 2013-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
*
*/
'use strict';
var MOD = 65521;
// adler32 is not cryptographically strong, and is only used to sanity check that
// markup generated on the server matches the markup generated on the client.
// This implementation (a modified version of the SheetJS version) has been optimized
// for our use case, at the expense of conforming to the adler32 specification
// for non-ascii inputs.
function adler32(data) {
var a = 1;
var b = 0;
var i = 0;
var l = data.length;
var m = l & ~0x3;
while (i < m) {
var n = Math.min(i + 4096, m);
for (; i < n; i += 4) {
b += (a += data.charCodeAt(i)) + (a += data.charCodeAt(i + 1)) + (a += data.charCodeAt(i + 2)) + (a += data.charCodeAt(i + 3));
}
a %= MOD;
b %= MOD;
}
for (; i < l; i++) {
b += a += data.charCodeAt(i);
}
a %= MOD;
b %= MOD;
return a | b << 16;
}
module.exports = adler32;
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