aaac7fed
 liuqimichale
add
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'use strict';
const crypto = require('crypto');
const xxh = require('xxhashjs');
const HEXBASE = 16;
const defaultHashOptions = {
method: 'xxhash32',
shrink: 8,
append: false
};
const getxxhash = (content, options) => {
const hashFunc = options.method === 'xxhash32' ? xxh.h32 : xxh.h64;
const seed = 0;
return hashFunc(seed)
.update(content)
.digest()
.toString(HEXBASE);
};
const getHash = (content, options) => {
if (options.method && typeof options.method === 'function') {
return options.method(content);
}
if (options.method && options.method.indexOf('xxhash') === 0) {
return getxxhash(content, options);
}
try {
const hashFunc = crypto.createHash(options.method);
return hashFunc.update(content)
.digest('hex');
} catch (e) {
return null;
}
};
module.exports = function(content, options) {
options = options || defaultHashOptions;
let hash = getHash(content, options);
if (hash == null) {
// bad hash method; fallback to defaults
// TODO: warning/error reporting?
hash = getHash(content, defaultHashOptions);
}
return options.shrink ? hash.substr(0, options.shrink) : hash;
};
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