Line data    Source code

       1            1 : const Int128Min = -170141183460469231731687303715884105728n;
       2            1 : const Int128Max = 170141183460469231731687303715884105727n;
       3            1 : const UInt128Max = 340282366920938463463374607431768211455n;
       4              : 
       5            1 : export class Int128 {
       6            1 :     static encodeLE(v: bigint) {
       7            1 :         if (v < Int128Min || v > Int128Max) throw Error("Input has to be between -(2^127) and (2^127)-1");
       8              : 
       9            1 :         const biguint = BigInt.asUintN(128, v);
      10            1 :         const buf = new ArrayBuffer(16);
      11            1 :         const bufView = new DataView(buf, 0, 16);
      12            1 :         bufView.setBigUint64(0, biguint & 0xffffffffffffffffn, true);
      13            1 :         bufView.setBigUint64(8, biguint >> 64n, true);
      14            1 :         return new Uint32Array(buf);
      15            1 :     }
      16              : 
      17            1 :     static decodeLE(buf: Uint32Array, offset = 0) {
      18            1 :         if (buf.byteLength < (offset + 16)) throw Error("Buffer out of range.");
      19              : 
      20            1 :         const bufView = new DataView(buf.buffer, buf.byteOffset, buf.byteLength);
      21            1 :         let biguint = bufView.getBigUint64(offset, true);
      22            1 :         biguint |= bufView.getBigUint64(offset + 8, true) << 64n;
      23            1 :         return BigInt.asIntN(128, biguint);
      24            1 :     }
      25            1 : }
      26              : 
      27            1 : export class UInt128 {
      28            1 :     static encodeLE(v: bigint) {
      29            1 :         if (v < 0n || v > UInt128Max) throw Error("Input has to be between 0 and (2^128)-1");
      30              : 
      31            1 :         const buf = new ArrayBuffer(16);
      32            1 :         const bufView = new DataView(buf, 0, 16);
      33            1 :         bufView.setBigUint64(0, v & 0xffffffffffffffffn, true);
      34            1 :         bufView.setBigUint64(8, v >> 64n, true);
      35            1 :         return new Uint32Array(buf);
      36            1 :     }
      37              : 
      38            1 :     static decodeLE(buf: Uint32Array, offset = 0) {
      39            1 :         if (buf.byteLength < (offset + 16)) throw Error("Buffer out of range.");
      40              : 
      41            1 :         const bufView = new DataView(buf.buffer, buf.byteOffset, buf.byteLength);
      42            1 :         let biguint = bufView.getBigUint64(offset, true);
      43            1 :         biguint |= bufView.getBigUint64(offset + 8, true) << 64n;
      44            1 :         return biguint;
      45            1 :     }
      46            1 : }
      47              : 
      48            1 : export class Decimal128 {
      49            1 :     static format(num: bigint, scale: number) {
      50              :         // Get int part
      51            1 :         const factor = BigInt(Math.pow(10, scale));
      52            1 :         const intPart = num / factor;
      53              :         // Get fraction part
      54            1 :         let fractionPart = num - (intPart * factor);
      55            1 :         if (fractionPart < 0n) fractionPart = ~fractionPart;
      56            1 :         const fractionStr = fractionPart.toString();
      57              : 
      58              :         // Cut trailing zeros
      59            1 :         let end = fractionStr.length;
      60            1 :         for (; end > 0 && fractionStr.charCodeAt(end - 1) == 0x30; --end);
      61              : 
      62              :         // Render with or without decimal dot
      63            1 :         if (end == 0) {
      64            1 :             return `${intPart.toString()}`;
      65              :         } else {
      66            1 :             return `${intPart.toString()}.${fractionStr.substring(0, end)}`;
      67              :         }
      68            1 :     }
      69            1 : }