--- /dev/null
+"use strict";
+module.exports = LongBits;
+
+var util = require("../util/minimal");
+
+/**
+ * Constructs new long bits.
+ * @classdesc Helper class for working with the low and high bits of a 64 bit value.
+ * @memberof util
+ * @constructor
+ * @param {number} lo Low 32 bits, unsigned
+ * @param {number} hi High 32 bits, unsigned
+ */
+function LongBits(lo, hi) {
+
+ // note that the casts below are theoretically unnecessary as of today, but older statically
+ // generated converter code might still call the ctor with signed 32bits. kept for compat.
+
+ /**
+ * Low bits.
+ * @type {number}
+ */
+ this.lo = lo >>> 0;
+
+ /**
+ * High bits.
+ * @type {number}
+ */
+ this.hi = hi >>> 0;
+}
+
+/**
+ * Zero bits.
+ * @memberof util.LongBits
+ * @type {util.LongBits}
+ */
+var zero = LongBits.zero = new LongBits(0, 0);
+
+zero.toNumber = function() { return 0; };
+zero.zzEncode = zero.zzDecode = function() { return this; };
+zero.length = function() { return 1; };
+
+/**
+ * Zero hash.
+ * @memberof util.LongBits
+ * @type {string}
+ */
+var zeroHash = LongBits.zeroHash = "\0\0\0\0\0\0\0\0";
+
+/**
+ * Constructs new long bits from the specified number.
+ * @param {number} value Value
+ * @returns {util.LongBits} Instance
+ */
+LongBits.fromNumber = function fromNumber(value) {
+ if (value === 0)
+ return zero;
+ var sign = value < 0;
+ if (sign)
+ value = -value;
+ var lo = value >>> 0,
+ hi = (value - lo) / 4294967296 >>> 0;
+ if (sign) {
+ hi = ~hi >>> 0;
+ lo = ~lo >>> 0;
+ if (++lo > 4294967295) {
+ lo = 0;
+ if (++hi > 4294967295)
+ hi = 0;
+ }
+ }
+ return new LongBits(lo, hi);
+};
+
+/**
+ * Constructs new long bits from a number, long or string.
+ * @param {Long|number|string} value Value
+ * @returns {util.LongBits} Instance
+ */
+LongBits.from = function from(value) {
+ if (typeof value === "number")
+ return LongBits.fromNumber(value);
+ if (util.isString(value)) {
+ /* istanbul ignore else */
+ if (util.Long)
+ value = util.Long.fromString(value);
+ else
+ return LongBits.fromNumber(parseInt(value, 10));
+ }
+ return value.low || value.high ? new LongBits(value.low >>> 0, value.high >>> 0) : zero;
+};
+
+/**
+ * Converts this long bits to a possibly unsafe JavaScript number.
+ * @param {boolean} [unsigned=false] Whether unsigned or not
+ * @returns {number} Possibly unsafe number
+ */
+LongBits.prototype.toNumber = function toNumber(unsigned) {
+ if (!unsigned && this.hi >>> 31) {
+ var lo = ~this.lo + 1 >>> 0,
+ hi = ~this.hi >>> 0;
+ if (!lo)
+ hi = hi + 1 >>> 0;
+ return -(lo + hi * 4294967296);
+ }
+ return this.lo + this.hi * 4294967296;
+};
+
+/**
+ * Converts this long bits to a long.
+ * @param {boolean} [unsigned=false] Whether unsigned or not
+ * @returns {Long} Long
+ */
+LongBits.prototype.toLong = function toLong(unsigned) {
+ return util.Long
+ ? new util.Long(this.lo | 0, this.hi | 0, Boolean(unsigned))
+ /* istanbul ignore next */
+ : { low: this.lo | 0, high: this.hi | 0, unsigned: Boolean(unsigned) };
+};
+
+var charCodeAt = String.prototype.charCodeAt;
+
+/**
+ * Constructs new long bits from the specified 8 characters long hash.
+ * @param {string} hash Hash
+ * @returns {util.LongBits} Bits
+ */
+LongBits.fromHash = function fromHash(hash) {
+ if (hash === zeroHash)
+ return zero;
+ return new LongBits(
+ ( charCodeAt.call(hash, 0)
+ | charCodeAt.call(hash, 1) << 8
+ | charCodeAt.call(hash, 2) << 16
+ | charCodeAt.call(hash, 3) << 24) >>> 0
+ ,
+ ( charCodeAt.call(hash, 4)
+ | charCodeAt.call(hash, 5) << 8
+ | charCodeAt.call(hash, 6) << 16
+ | charCodeAt.call(hash, 7) << 24) >>> 0
+ );
+};
+
+/**
+ * Converts this long bits to a 8 characters long hash.
+ * @returns {string} Hash
+ */
+LongBits.prototype.toHash = function toHash() {
+ return String.fromCharCode(
+ this.lo & 255,
+ this.lo >>> 8 & 255,
+ this.lo >>> 16 & 255,
+ this.lo >>> 24 ,
+ this.hi & 255,
+ this.hi >>> 8 & 255,
+ this.hi >>> 16 & 255,
+ this.hi >>> 24
+ );
+};
+
+/**
+ * Zig-zag encodes this long bits.
+ * @returns {util.LongBits} `this`
+ */
+LongBits.prototype.zzEncode = function zzEncode() {
+ var mask = this.hi >> 31;
+ this.hi = ((this.hi << 1 | this.lo >>> 31) ^ mask) >>> 0;
+ this.lo = ( this.lo << 1 ^ mask) >>> 0;
+ return this;
+};
+
+/**
+ * Zig-zag decodes this long bits.
+ * @returns {util.LongBits} `this`
+ */
+LongBits.prototype.zzDecode = function zzDecode() {
+ var mask = -(this.lo & 1);
+ this.lo = ((this.lo >>> 1 | this.hi << 31) ^ mask) >>> 0;
+ this.hi = ( this.hi >>> 1 ^ mask) >>> 0;
+ return this;
+};
+
+/**
+ * Calculates the length of this longbits when encoded as a varint.
+ * @returns {number} Length
+ */
+LongBits.prototype.length = function length() {
+ var part0 = this.lo,
+ part1 = (this.lo >>> 28 | this.hi << 4) >>> 0,
+ part2 = this.hi >>> 24;
+ return part2 === 0
+ ? part1 === 0
+ ? part0 < 16384
+ ? part0 < 128 ? 1 : 2
+ : part0 < 2097152 ? 3 : 4
+ : part1 < 16384
+ ? part1 < 128 ? 5 : 6
+ : part1 < 2097152 ? 7 : 8
+ : part2 < 128 ? 9 : 10;
+};