int64.js

// ------------------------------------------------------------------------------
// Code generated by the Fast Binary Encoding compiler. DO NOT EDIT.
// https://github.com/chronoxor/FastBinaryEncoding
// Source: FBE
// FBE version: 1.15.0.0
// ------------------------------------------------------------------------------

/* eslint-disable prefer-const,no-loss-of-precision */
'use strict'

/**
 * Signed 64-bit integer value
 */
class Int64 {
  /**
   * Initialize signed 64-bit integer value with high & low parts
   * @param {number} low The low 32-bit part
   * @param {number} high The high 32-bit part
   * @constructor
   */
  constructor (low, high) {
    this.low = low | 0
    this.high = high | 0
  }

  /**
   * Zero value constant
   * @returns {!Int64}
   */
  static get ZERO () { return INT64_ZERO }

  /**
   * Minimal value constant
   * @returns {!Int64}
   */
  static get MIN () { return INT64_MIN }

  /**
   * Maximal value constant
   * @returns {!Int64}
   */
  static get MAX () { return INT64_MAX }

  /**
   * Is the specified object Int64?
   * @param obj Object to check
   * @returns {!boolean}
   */
  static isInt64 (obj) {
    return (obj && obj.__isInt64__) === true
  }

  /**
   * Returns Int64 representing the 64 bit integer that comes by concatenating the given low and high 32 bits parts
   * @param {number} lowBits The low 32-bit part
   * @param {number} highBits The high 32-bit part
   * @returns {!Int64} The corresponding Int64 value
   */
  static fromBits (lowBits, highBits) {
    return new Int64(lowBits, highBits)
  }

  /**
   * Returns Int64 from its bytes representation
   * @param {!Array.<number>} bytes Bytes representation
   * @param {boolean=} le Whether little or big endian, defaults to little endian
   * @returns {!Int64} The corresponding Int64 value
   */
  static fromBytes (bytes, le = true) {
    return le ? Int64.fromBytesLE(bytes) : Int64.fromBytesBE(bytes)
  }

  /**
   * Returns Int64 from its bytes representation (bid endian)
   * @param {!Array.<number>} bytes Bytes representation
   * @returns {!Int64} The corresponding Int64 value
   */
  static fromBytesBE (bytes) {
    return new Int64(
      bytes[4] << 24 |
      bytes[5] << 16 |
      bytes[6] << 8 |
      bytes[7] << 0,
      bytes[0] << 24 |
      bytes[1] << 16 |
      bytes[2] << 8 |
      bytes[3] << 0
    )
  }

  /**
   * Returns Int64 from its bytes representation (little endian)
   * @param {!Array.<number>} bytes Bytes representation
   * @returns {!Int64} The corresponding Int64 value
   */
  static fromBytesLE (bytes) {
    return new Int64(
      bytes[0] << 0 |
      bytes[1] << 8 |
      bytes[2] << 16 |
      bytes[3] << 24,
      bytes[4] << 0 |
      bytes[5] << 8 |
      bytes[6] << 16 |
      bytes[7] << 24
    )
  }

  /**
   * Returns Int64 representing the given 32-bit integer value
   * @param {number} value 32-bit integer value
   * @returns {!Int64} The corresponding Int64 value
   */
  static fromInt32 (value) {
    value |= 0

    let cache = ((value >= -128) && (value < 128))
    if (cache) {
      let cached = Int64Cache[value]
      if (cached) {
        return cached
      }
    }

    let result = Int64.fromBits(value, (value < 0) ? -1 : 0)

    if (cache) {
      Int64Cache[value] = result
    }

    return result
  }

  /**
   * Returns Int64 representing the given value, provided that it is a finite number. Otherwise, zero is returned.
   * @param {number} value 32-bit integer value
   * @returns {!Int64} The corresponding Int64 value
   */
  static fromNumber (value) {
    if (isNaN(value)) {
      return INT64_ZERO
    }
    if (value <= -INT64_TWO_PWR_63_DBL) {
      return INT64_MIN
    }
    if (value + 1 >= INT64_TWO_PWR_63_DBL) {
      return INT64_MAX
    }
    if (value < 0) {
      return Int64.fromNumber(-value).neg()
    }
    return Int64.fromBits((value % INT64_TWO_PWR_32_DBL) | 0, (value / INT64_TWO_PWR_32_DBL) | 0)
  }

  /**
   * Returns Int64 representation of the given string, written using the specified radix.
   * @param {string} str The textual representation of the Int64
   * @param {number=} radix The radix in which the text is written (2-36), defaults to 10
   * @returns {!Int64} The corresponding Int64 value
   */
  static fromString (str, radix = 10) {
    if (str.length === 0) {
      throw new Error('Empty string!')
    }
    if ((str === 'NaN') || (str === 'Infinity') || (str === '+Infinity') || (str === '-Infinity')) {
      return INT64_ZERO
    }
    radix = radix || 10
    if ((radix < 2) || (radix > 36)) {
      throw new RangeError('radix')
    }

    let p = str.indexOf('-')
    if (p > 0) {
      throw new Error('Interior hyphen!')
    } else if (p === 0) {
      return Int64.fromString(str.substring(1), radix).neg()
    }

    // Do several (8) digits each time through the loop, so as to
    // minimize the calls to the very expensive emulated div.
    let radixToPower = Int64.fromNumber(Math.pow(radix, 8))

    let result = INT64_ZERO
    for (let i = 0; i < str.length; i += 8) {
      let size = Math.min(8, str.length - i)
      let value = parseInt(str.substring(i, i + size), radix)
      if (size < 8) {
        let power = Int64.fromNumber(Math.pow(radix, size))
        result = result.mul(power).add(Int64.fromNumber(value))
      } else {
        result = result.mul(radixToPower)
        result = result.add(Int64.fromNumber(value))
      }
    }
    return result
  }

  /**
   * Converts the specified value to a Int64 using the appropriate from* function for its type.
   * @param {!Int64|!UInt64|number|string} value Value
   * @returns {!Int64} The corresponding Int64 value
   */
  static fromValue (value) {
    if (typeof value === 'number') {
      return Int64.fromNumber(value)
    }
    if (typeof value === 'string') {
      return Int64.fromString(value, 10)
    }
    return Int64.fromBits(value.low, value.high)
  }

  /**
   * Converts the Int64 to its bytes representation
   * @this {!Int64}
   * @param {boolean=} le Whether little or big endian, defaults to little endian
   * @returns {!Array.<number>} Bytes representation
   */
  toBytes (le = true) {
    return le ? this.toBytesLE() : this.toBytesBE()
  }

  /**
   * Converts the Int64 to its bytes representation (big endian)
   * @this {!Int64}
   * @returns {!Array.<number>} Bytes representation
   */
  toBytesBE () {
    let hi = this.high
    let lo = this.low
    return [
      hi >>> 24 & 0xFF,
      hi >>> 16 & 0xFF,
      hi >>> 8 & 0xFF,
      hi >>> 0 & 0xFF,
      lo >>> 24 & 0xFF,
      lo >>> 16 & 0xFF,
      lo >>> 8 & 0xFF,
      lo >>> 0 & 0xFF
    ]
  }

  /**
   * Converts the Int64 to its bytes representation (little endian)
   * @this {!Int64}
   * @returns {!Array.<number>} Bytes representation
   */
  toBytesLE () {
    let hi = this.high
    let lo = this.low
    return [
      lo >>> 0 & 0xFF,
      lo >>> 8 & 0xFF,
      lo >>> 16 & 0xFF,
      lo >>> 24 & 0xFF,
      hi >>> 0 & 0xFF,
      hi >>> 8 & 0xFF,
      hi >>> 16 & 0xFF,
      hi >>> 24 & 0xFF
    ]
  }

  /**
   * Converts the Int64 to a 32-bit integer, assuming it is a 32-bit integer
   * @this {!Int64}
   * @returns {number} Result 32-bit integer
   */
  toInt32 () {
    return this.low
  }

  /**
   * Converts the Int64 to a the nearest floating-point representation of this value (double, 53 bit mantissa)
   * @this {!Int64}
   * @returns {number} Result number
   */
  toNumber () {
    return this.high * INT64_TWO_PWR_32_DBL + (this.low >>> 0)
  }

  /**
   * Converts the Int64 to a string written in the specified radix
   * @this {!Int64}
   * @param {number=} radix Radix (2-36), defaults to 10
   * @returns {string} Result string
   */
  toString (radix = 10) {
    radix = radix || 10
    if ((radix < 2) || (radix > 36)) {
      throw new RangeError('Radix must be in range [2, 36]')
    }
    if (this.isZero) {
      return '0'
    }
    if (this.isNegative) {
      if (this.eq(INT64_MIN)) {
        // We need to change the Long value before it can be negated, so we remove
        // the bottom-most digit in this base and then recurse to do the rest.
        let radixLong = Int64.fromNumber(radix)
        let div = this.div(radixLong)
        let rem1 = div.mul(radixLong).sub(this)
        return div.toString(radix) + rem1.toInt32().toString(radix)
      } else {
        return '-' + this.neg().toString(radix)
      }
    }

    // Do several (6) digits each time through the loop, so as to
    // minimize the calls to the very expensive emulated div.
    let radixToPower = Int64.fromNumber(Math.pow(radix, 6))
    let rem = this
    let result = ''
    while (true) {
      let remDiv = rem.div(radixToPower)
      let intval = rem.sub(remDiv.mul(radixToPower)).toInt32() >>> 0
      let digits = intval.toString(radix)
      rem = remDiv
      if (rem.isZero) {
        return digits + result
      } else {
        while (digits.length < 6) {
          digits = '0' + digits
        }
        result = '' + digits + result
      }
    }
  }

  /**
   * Converts the Int64 to Int64
   * @this {!Int64}
   * @returns {!Int64} Result Int64 number
   */
  toSigned () {
    return this
  }

  /**
   * Converts the Int64 to UInt64
   * @this {!Int64}
   * @returns {!UInt64} Result UInt64 number
   */
  toUnsigned () {
    return UInt64.fromBits(this.low, this.high)
  }

  /**
   * Get the high 32 bits as a signed integer
   * @this {!Int64}
   * @returns {number} Signed high bits
   */
  get HighBits () {
    return this.high
  }

  /**
   * Get the high 32 bits as an unsigned integer
   * @this {!Int64}
   * @returns {number} Unsigned high bits
   */
  get HighBitsUnsigned () {
    return this.high >>> 0
  }

  /**
   * Get the low 32 bits as a signed integer
   * @this {!Int64}
   * @returns {number} Signed low bits
   */
  get LowBits () {
    return this.low
  }

  /**
   * Get the low 32 bits as an unsigned integer
   * @this {!Int64}
   * @returns {number} Unsigned low bits
   */
  get LowBitsUnsigned () {
    return this.low >>> 0
  }

  /**
   * Get the number of bits needed to represent the absolute value of this Int64
   * @this {!Int64}
   * @returns {number} Number of represented bits
   */
  get NumBits () {
    if (this.isNegative) {
      return this.eq(INT64_MIN) ? 64 : this.neg().NumBits
    }

    let val = (this.high !== 0) ? this.high : this.low

    let bit
    for (bit = 31; bit > 0; bit--) {
      if ((val & (1 << bit)) !== 0) {
        break
      }
    }

    return (this.high !== 0) ? (bit + 33) : (bit + 1)
  }

  /**
   * Is this value zero?
   * @this {!Int64}
   * @returns {boolean} Zero test result
   */
  get isZero () {
    return (this.high === 0) && (this.low === 0)
  }

  /**
   * Is this value positive?
   * @this {!Int64}
   * @returns {boolean} Positive test result
   */
  get isPositive () {
    return this.high >= 0
  }

  /**
   * Is this value negative?
   * @this {!Int64}
   * @returns {boolean} Negative test result
   */
  get isNegative () {
    return this.high < 0
  }

  /**
   * Is this value odd?
   * @this {!Int64}
   * @returns {boolean} Odd test result
   */
  get isOdd () {
    return (this.low & 1) === 1
  }

  /**
   * Is this value even?
   * @this {!Int64}
   * @returns {boolean} Even test result
   */
  get isEven () {
    return (this.low & 1) === 0
  }

  /**
   * Is this value equal to other one?
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {boolean} Equal result
   */
  eq (other) {
    if (UInt64.isUInt64(other)) {
      if (((this.high >>> 31) === 1) && ((other.high >>> 31) === 1)) {
        return false
      }
    } else if (!Int64.isInt64(other)) {
      other = Int64.fromValue(other)
    }
    return (this.high === other.high) && (this.low === other.low)
  }

  /**
   * Is this value not equal to other one?
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {boolean} Not equal result
   */
  ne (other) {
    return !this.eq(other)
  }

  /**
   * Is this value less than other one?
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {boolean} Less than result
   */
  lt (other) {
    return this.cmp(other) < 0
  }

  /**
   * Is this value less than or equal other one?
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {boolean} Less than or equal result
   */
  lte (other) {
    return this.cmp(other) <= 0
  }

  /**
   * Is this value greater than other one?
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {boolean} Greater than result
   */
  gt (other) {
    return this.cmp(other) > 0
  }

  /**
   * Is this value greater than or equal other one?
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {boolean} Greater than or equal result
   */
  gte (other) {
    return this.cmp(other) >= 0
  }

  /**
   * Compare this value to other one
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {number} 0 if they are the same, 1 if the this is greater and -1 if the given one is greater
   */
  cmp (other) {
    if (!Int64.isInt64(other) && !UInt64.isUInt64(other)) {
      other = Int64.fromValue(other)
    }
    if (this.eq(other)) {
      return 0
    }
    let thisNeg = this.isNegative
    let otherNeg = other.isNegative
    if (thisNeg && !otherNeg) {
      return -1
    }
    if (!thisNeg && otherNeg) {
      return 1
    }
    // At this point the sign bits are the same
    return this.sub(other).isNegative ? -1 : 1
  }

  /**
   * Negates this value
   * @this {!Int64}
   * @returns {!Int64} Negated value
   */
  neg () {
    if (this.eq(INT64_MIN)) {
      return INT64_MIN
    }
    return this.not().add(INT64_ONE)
  }

  /**
   * Add this value to other one
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {!Int64} Sum of the values
   */
  add (other) {
    if (!Int64.isInt64(other) && !UInt64.isUInt64(other)) {
      other = Int64.fromValue(other)
    }

    // Divide each number into 4 chunks of 16 bits, and then sum the chunks

    let a48 = this.high >>> 16
    let a32 = this.high & 0xFFFF
    let a16 = this.low >>> 16
    let a00 = this.low & 0xFFFF

    let b48 = other.high >>> 16
    let b32 = other.high & 0xFFFF
    let b16 = other.low >>> 16
    let b00 = other.low & 0xFFFF

    let c48 = 0
    let c32 = 0
    let c16 = 0
    let c00 = 0
    c00 += a00 + b00
    c16 += c00 >>> 16
    c00 &= 0xFFFF
    c16 += a16 + b16
    c32 += c16 >>> 16
    c16 &= 0xFFFF
    c32 += a32 + b32
    c48 += c32 >>> 16
    c32 &= 0xFFFF
    c48 += a48 + b48
    c48 &= 0xFFFF
    return Int64.fromBits((c16 << 16) | c00, (c48 << 16) | c32)
  }

  /**
   * Subtract other value from this value
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {!Int64} Difference of two values
   */
  sub (other) {
    if (!Int64.isInt64(other) && !UInt64.isUInt64(other)) {
      other = Int64.fromValue(other)
    }
    return this.add(other.neg())
  }

  /**
   * Multiply this value with other one
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {!Int64} Multiplication of two values
   */
  mul (other) {
    if (this.isZero) {
      return INT64_ZERO
    }
    if (!Int64.isInt64(other) && !UInt64.isUInt64(other)) {
      other = Int64.fromValue(other)
    }

    if (other.isZero) {
      return INT64_ZERO
    }
    if (this.eq(INT64_MIN)) {
      return other.isOdd ? INT64_MIN : INT64_ZERO
    }
    if (other.eq(INT64_MIN)) {
      return this.isOdd ? INT64_MIN : INT64_ZERO
    }

    if (this.isNegative) {
      if (other.isNegative) {
        return this.neg().mul(other.neg())
      } else {
        return this.neg().mul(other).neg()
      }
    } else if (other.isNegative) {
      return this.mul(other.neg()).neg()
    }

    // If both longs are small, use float multiplication
    if (this.lt(INT64_TWO_PWR_24) && other.lt(INT64_TWO_PWR_24)) {
      return Int64.fromNumber(this.toNumber() * other.toNumber())
    }

    // Divide each long into 4 chunks of 16 bits, and then add up 4x4 products.
    // We can skip products that would overflow.

    let a48 = this.high >>> 16
    let a32 = this.high & 0xFFFF
    let a16 = this.low >>> 16
    let a00 = this.low & 0xFFFF

    let b48 = other.high >>> 16
    let b32 = other.high & 0xFFFF
    let b16 = other.low >>> 16
    let b00 = other.low & 0xFFFF

    let c48 = 0
    let c32 = 0
    let c16 = 0
    let c00 = 0
    c00 += a00 * b00
    c16 += c00 >>> 16
    c00 &= 0xFFFF
    c16 += a16 * b00
    c32 += c16 >>> 16
    c16 &= 0xFFFF
    c16 += a00 * b16
    c32 += c16 >>> 16
    c16 &= 0xFFFF
    c32 += a32 * b00
    c48 += c32 >>> 16
    c32 &= 0xFFFF
    c32 += a16 * b16
    c48 += c32 >>> 16
    c32 &= 0xFFFF
    c32 += a00 * b32
    c48 += c32 >>> 16
    c32 &= 0xFFFF
    c48 += a48 * b00 + a32 * b16 + a16 * b32 + a00 * b48
    c48 &= 0xFFFF
    return Int64.fromBits((c16 << 16) | c00, (c48 << 16) | c32)
  }

  /**
   * Divide this value by other one
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {!Int64} Division of two values
   */
  div (other) {
    if (!Int64.isInt64(other) && !UInt64.isUInt64(other)) {
      other = Int64.fromValue(other)
    }
    if (other.isZero) {
      throw new Error('Division by zero!')
    }

    if (this.isZero) {
      return INT64_ZERO
    }

    let approx, rem, res

    // This section is only relevant for signed longs and is derived from the closure library as a whole
    if (this.eq(INT64_MIN)) {
      // Recall that -MIN_VALUE == MIN_VALUE
      if (other.eq(INT64_ONE) || other.eq(INT64_NEG_ONE)) {
        return INT64_MIN
      } else if (other.eq(INT64_MIN)) {
        return INT64_ONE
      } else {
        // At this point, we have |other| >= 2, so |this/other| < |MIN_VALUE|
        let halfThis = this.shr(1)
        approx = halfThis.div(other).shl(1)
        if (approx.eq(INT64_ZERO)) {
          return other.isNegative ? INT64_ONE : INT64_NEG_ONE
        } else {
          rem = this.sub(other.mul(approx))
          res = approx.add(rem.div(other))
          return res
        }
      }
    } else if (other.eq(INT64_MIN)) {
      return INT64_ZERO
    }

    if (this.isNegative) {
      if (other.isNegative) {
        return this.neg().div(other.neg())
      }
      return this.neg().div(other).neg()
    } else if (other.isNegative) {
      return this.div(other.neg()).neg()
    }
    res = INT64_ZERO

    // Repeat the following until the remainder is less than other:  find a floating-point that approximates
    // remainder / other *from below*, add this into the result, and subtract it from the remainder.
    // It is critical that the approximate value is less than or equal to the real value so that the
    // remainder never becomes negative.
    rem = this
    while (rem.gte(other)) {
      // Approximate the result of division. This may be a little greater or smaller than the actual value
      approx = Math.max(1, Math.floor(rem.toNumber() / other.toNumber()))

      // We will tweak the approximate result by changing it in the 48-th digit or the smallest non-fractional
      // digit, whichever is larger.
      let log2 = Math.ceil(Math.log(approx) / Math.LN2)
      let delta = (log2 <= 48) ? 1 : Math.pow(2, log2 - 48)

      // Decrease the approximation until it is smaller than the remainder.
      // Note that if it is too large, the product overflows and is negative.
      let approxRes = Int64.fromNumber(approx)
      let approxRem = approxRes.mul(other)
      while (approxRem.isNegative || approxRem.gt(rem)) {
        approx -= delta
        approxRes = Int64.fromNumber(approx)
        approxRem = approxRes.mul(other)
      }

      // We know the answer can't be zero... and actually, zero would cause infinite recursion since
      // we would make no progress.
      if (approxRes.isZero) {
        approxRes = INT64_ONE
      }

      res = res.add(approxRes)
      rem = rem.sub(approxRem)
    }
    return res
  }

  /**
   * Modulo this value by other one
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {!Int64} Module of two values
   */
  mod (other) {
    if (!Int64.isInt64(other) && !UInt64.isUInt64(other)) {
      other = Int64.fromValue(other)
    }
    return this.sub(this.div(other).mul(other))
  }

  /**
   * Bitwise NOT this value
   * @this {!Int64}
   * @returns {!Int64} Bitwise NOT result value
   */
  not () {
    return Int64.fromBits(~this.low, ~this.high)
  }

  /**
   * Bitwise AND this value and other one
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {!Int64} Bitwise AND result value
   */
  and (other) {
    if (!Int64.isInt64(other) && !UInt64.isUInt64(other)) {
      other = Int64.fromValue(other)
    }
    return Int64.fromBits(this.low & other.low, this.high & other.high)
  }

  /**
   * Bitwise OR this value and other one
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {!Int64} Bitwise OR result value
   */
  or (other) {
    if (!Int64.isInt64(other) && !UInt64.isUInt64(other)) {
      other = Int64.fromValue(other)
    }
    return Int64.fromBits(this.low | other.low, this.high | other.high)
  }

  /**
   * Bitwise XOR this value and other one
   * @this {!Int64}
   * @param {!Int64|!UInt64|number|string} other Other value
   * @returns {!Int64} Bitwise XOR result value
   */
  xor (other) {
    if (!Int64.isInt64(other) && !UInt64.isUInt64(other)) {
      other = Int64.fromValue(other)
    }
    return Int64.fromBits(this.low ^ other.low, this.high ^ other.high)
  }

  /**
   * This Int64 with bits shifted to the left by the given amount
   * @this {!Int64}
   * @param {Int64|UInt64|number} numBits Number of bits
   * @returns {!Int64} Shifted result value
   */
  shl (numBits) {
    if (Int64.isInt64(numBits) || UInt64.isUInt64(numBits)) {
      numBits = numBits.toInt32()
    }
    if ((numBits &= 63) === 0) {
      return this
    } else if (numBits < 32) {
      return Int64.fromBits(this.low << numBits, (this.high << numBits) | (this.low >>> (32 - numBits)))
    } else {
      return Int64.fromBits(0, this.low << (numBits - 32))
    }
  }

  /**
   * This Int64 with bits shifted to the right by the given amount
   * @this {!Int64}
   * @param {Int64|UInt64|number} numBits Number of bits
   * @returns {!Int64} Shifted result value
   */
  shr (numBits) {
    if (Int64.isInt64(numBits) || UInt64.isUInt64(numBits)) {
      numBits = numBits.toInt32()
    }
    if ((numBits &= 63) === 0) {
      return this
    } else if (numBits < 32) {
      return Int64.fromBits((this.low >>> numBits) | (this.high << (32 - numBits)), this.high >> numBits)
    } else {
      return Int64.fromBits(this.high >> (numBits - 32), (this.high >= 0) ? 0 : -1)
    }
  }

  /**
   * This Int64 with bits shifted to the right by the given amount with filling zeros to the left
   * @this {!Int64}
   * @param {Int64|UInt64|number} numBits Number of bits
   * @returns {!Int64} Shifted result value
   */
  shru (numBits) {
    if (Int64.isInt64(numBits) || UInt64.isUInt64(numBits)) {
      numBits = numBits.toInt32()
    }
    numBits &= 63
    if (numBits === 0) {
      return this
    } else {
      let high = this.high
      if (numBits < 32) {
        let low = this.low
        return Int64.fromBits((low >>> numBits) | (high << (32 - numBits)), high >>> numBits)
      } else if (numBits === 32) {
        return Int64.fromBits(high, 0)
      } else {
        return Int64.fromBits(high >>> (numBits - 32), 0)
      }
    }
  }
}

Object.defineProperty(Int64.prototype, '__isInt64__', { value: true })

// Useful constants
const INT64_TWO_PWR_16_DBL = 1 << 16
const INT64_TWO_PWR_24_DBL = 1 << 24
const INT64_TWO_PWR_32_DBL = INT64_TWO_PWR_16_DBL * INT64_TWO_PWR_16_DBL
const INT64_TWO_PWR_64_DBL = INT64_TWO_PWR_32_DBL * INT64_TWO_PWR_32_DBL
const INT64_TWO_PWR_63_DBL = INT64_TWO_PWR_64_DBL / 2

// Int64 values cache
const Int64Cache = {}

// Int64 values constants
const INT64_ZERO = Int64.fromInt32(0)
const INT64_ONE = Int64.fromInt32(1)
const INT64_NEG_ONE = Int64.fromInt32(-1)
const INT64_MIN = Int64.fromBits(0, 0x80000000 | 0)
const INT64_MAX = Int64.fromBits(0xFFFFFFFF | 0, 0x7FFFFFFF | 0)
const INT64_TWO_PWR_24 = Int64.fromInt32(INT64_TWO_PWR_24_DBL)

exports.Int64 = Int64

/**
 * Unsigned 64-bit integer value
 */
class UInt64 {
  /**
   * Initialize unsigned 64-bit integer value with high & low parts
   * @param {number} low The low 32-bit part
   * @param {number} high The high 32-bit part
   * @constructor
   */
  constructor (low, high) {
    this.low = low | 0
    this.high = high | 0
  }

  /**
   * Zero value constant
   * @returns {!UInt64}
   */
  static get ZERO () { return UINT64_ZERO }

  /**
   * Minimal value constant
   * @returns {!UInt64}
   */
  static get MIN () { return UINT64_MIN }

  /**
   * Maximal value constant
   * @returns {!UInt64}
   */
  static get MAX () { return UINT64_MAX }

  /**
   * Is the specified object UInt64?
   * @param obj Object to check
   * @returns {boolean}
   */
  static isUInt64 (obj) {
    return (obj && obj.__isUInt64__) === true
  }

  /**
   * Returns UInt64 representing the 64 bit integer that comes by concatenating the given low and high 32 bits parts
   * @param {number} lowBits The low 32-bit part
   * @param {number} highBits The high 32-bit part
   * @returns {!UInt64} The corresponding UInt64 value
   */
  static fromBits (lowBits, highBits) {
    return new UInt64(lowBits, highBits)
  }

  /**
   * Returns UInt64 from its bytes representation
   * @param {!Array.<number>} bytes Bytes representation
   * @param {boolean=} le Whether little or big endian, defaults to little endian
   * @returns {!UInt64} The corresponding Int64 value
   */
  static fromBytes (bytes, le = true) {
    return le ? UInt64.fromBytesLE(bytes) : UInt64.fromBytesBE(bytes)
  }

  /**
   * Returns UInt64 from its bytes representation (bid endian)
   * @param {!Array.<number>} bytes Bytes representation
   * @returns {!UInt64} The corresponding Int64 value
   */
  static fromBytesBE (bytes) {
    return new UInt64(
      bytes[4] << 24 |
      bytes[5] << 16 |
      bytes[6] << 8 |
      bytes[7] << 0,
      bytes[0] << 24 |
      bytes[1] << 16 |
      bytes[2] << 8 |