mirror of https://github.com/jkjoy/sunpeiwen.git
37 lines
972 B
JavaScript
37 lines
972 B
JavaScript
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var Buffer = require('buffer').Buffer;
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var intSize = 4;
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var zeroBuffer = Buffer.alloc(intSize);
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zeroBuffer.fill(0);
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var chrsz = 8;
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function toArray(buf, bigEndian) {
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if (buf.length % intSize !== 0) {
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var len = buf.length + (intSize - (buf.length % intSize));
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buf = Buffer.concat([buf, zeroBuffer], len);
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}
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var arr = [];
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var fn = bigEndian ? buf.readInt32BE : buf.readInt32LE;
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for (var i = 0; i < buf.length; i += intSize) {
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arr.push(fn.call(buf, i));
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}
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return arr;
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}
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function toBuffer(arr, size, bigEndian) {
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var buf = Buffer.alloc(size);
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var fn = bigEndian ? buf.writeInt32BE : buf.writeInt32LE;
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for (var i = 0; i < arr.length; i++) {
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fn.call(buf, arr[i], i * 4, true);
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}
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return buf;
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}
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function hash(buf, fn, hashSize, bigEndian) {
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if (!Buffer.isBuffer(buf)) buf = Buffer.from(buf);
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var arr = fn(toArray(buf, bigEndian), buf.length * chrsz);
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return toBuffer(arr, hashSize, bigEndian);
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}
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module.exports = { hash: hash };
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