Add Compact{16,32,64,128,256} (#219)

* Add Compact{16,32,64,128,256}

* Pass Compact encoding/decoding length, set default

* Align default length naming with Compact

packages/types/src/Bytes.ts

@@ -4,7 +4,7 @@
 
 import u8aConcat from '@polkadot/util/u8a/concat';
 
-import Compact from './codec/Compact';
+import Compact, { DEFAULT_LENGTH_BITS } from './codec/Compact';
 import U8a from './codec/U8a';
 
 // A Bytes. The significant difference between this and a normal Uint8Array is that
@@ -16,11 +16,11 @@ export default class Bytes extends U8a {
   }
 
   byteLength (): number {
-    return this.length + Compact.encode(this.length).length;
+    return this.length + Compact.encodeU8a(this.length, DEFAULT_LENGTH_BITS).length;
   }
 
   fromU8a (input: Uint8Array): Bytes {
-    const [offset, length] = Compact.decode(input);
+    const [offset, length] = Compact.decodeU8a(input, DEFAULT_LENGTH_BITS);
 
     super.fromU8a(input.subarray(offset, offset + length.toNumber()));
 
@@ -31,7 +31,7 @@ export default class Bytes extends U8a {
     return isBare
       ? this.raw
       : u8aConcat(
-        Compact.encode(this.length),
+        Compact.encodeU8a(this.length, DEFAULT_LENGTH_BITS),
         this.raw
       );
   }

packages/types/src/Compact128.ts

@@ -0,0 +1,13 @@
+// Copyright 2017-2018 @polkadot/types authors & contributors
+// This software may be modified and distributed under the terms
+// of the ISC license. See the LICENSE file for details.
+
+import { AnyNumber } from './types';
+
+import Compact from './codec/Compact';
+
+export default class Compact128 extends Compact {
+  constructor (value?: AnyNumber) {
+    super(value, 128);
+  }
+}

packages/types/src/Compact16.ts

@@ -0,0 +1,13 @@
+// Copyright 2017-2018 @polkadot/types authors & contributors
+// This software may be modified and distributed under the terms
+// of the ISC license. See the LICENSE file for details.
+
+import { AnyNumber } from './types';
+
+import Compact from './codec/Compact';
+
+export default class Compact16 extends Compact {
+  constructor (value?: AnyNumber) {
+    super(value, 16, false);
+  }
+}

packages/types/src/Compact256.ts

@@ -0,0 +1,13 @@
+// Copyright 2017-2018 @polkadot/types authors & contributors
+// This software may be modified and distributed under the terms
+// of the ISC license. See the LICENSE file for details.
+
+import { AnyNumber } from './types';
+
+import Compact from './codec/Compact';
+
+export default class Compact256 extends Compact {
+  constructor (value?: AnyNumber) {
+    super(value, 256);
+  }
+}

packages/types/src/Compact32.ts

@@ -0,0 +1,13 @@
+// Copyright 2017-2018 @polkadot/types authors & contributors
+// This software may be modified and distributed under the terms
+// of the ISC license. See the LICENSE file for details.
+
+import { AnyNumber } from './types';
+
+import Compact from './codec/Compact';
+
+export default class Compact32 extends Compact {
+  constructor (value?: AnyNumber) {
+    super(value, 32, false);
+  }
+}

packages/types/src/Compact64.ts

@@ -0,0 +1,13 @@
+// Copyright 2017-2018 @polkadot/types authors & contributors
+// This software may be modified and distributed under the terms
+// of the ISC license. See the LICENSE file for details.
+
+import { AnyNumber } from './types';
+
+import Compact from './codec/Compact';
+
+export default class Compact64 extends Compact {
+  constructor (value?: AnyNumber) {
+    super(value, 64, false);
+  }
+}

packages/types/src/Extrinsic.ts

@@ -10,7 +10,7 @@ import hexToU8a from '@polkadot/util/hex/toU8a';
 import u8aConcat from '@polkadot/util/u8a/concat';
 import u8aToHex from '@polkadot/util/u8a/toHex';
 
-import Compact from './codec/Compact';
+import Compact, { DEFAULT_LENGTH_BITS } from './codec/Compact';
 import Struct from './codec/Struct';
 import ExtrinsicSignature from './ExtrinsicSignature';
 import Hash from './Hash';
@@ -79,7 +79,7 @@ export default class Extrinsic extends Struct {
   byteLength (): number {
     const length = this.length;
 
-    return length + Compact.encode(length).length;
+    return length + Compact.encodeU8a(length, DEFAULT_LENGTH_BITS).length;
   }
 
   fromJSON (input: any): Extrinsic {
@@ -89,7 +89,7 @@ export default class Extrinsic extends Struct {
   }
 
   fromU8a (input: Uint8Array): Extrinsic {
-    const [offset, length] = Compact.decode(input);
+    const [offset, length] = Compact.decodeU8a(input, DEFAULT_LENGTH_BITS);
 
     super.fromU8a(input.subarray(offset, offset + length.toNumber()));
 
@@ -108,7 +108,7 @@ export default class Extrinsic extends Struct {
     return isBare
       ? encoded
       : u8aConcat(
-        Compact.encode(encoded.length),
+        Compact.encodeU8a(encoded.length, DEFAULT_LENGTH_BITS),
         encoded
       );
   }

packages/types/src/Text.ts

@@ -7,7 +7,7 @@ import u8aToUtf8 from '@polkadot/util/u8a/toUtf8';
 import u8aConcat from '@polkadot/util/u8a/concat';
 
 import Base from './codec/Base';
-import Compact from './codec/Compact';
+import Compact, { DEFAULT_LENGTH_BITS } from './codec/Compact';
 
 // This is a string wrapper, along with the length. It is used both for strings as well
 // as stuff like documentation.
@@ -31,11 +31,11 @@ export default class Text extends Base<string> {
   }
 
   byteLength (): number {
-    return this.length + Compact.encode(this.length).length;
+    return this.length + Compact.encodeU8a(this.length, DEFAULT_LENGTH_BITS).length;
   }
 
   fromU8a (input: Uint8Array): Text {
-    const [offset, length] = Compact.decode(input);
+    const [offset, length] = Compact.decodeU8a(input, DEFAULT_LENGTH_BITS);
 
     this.raw = u8aToUtf8(input.subarray(offset, offset + length.toNumber()));
 
@@ -62,7 +62,7 @@ export default class Text extends Base<string> {
     return isBare
       ? encoded
       : u8aConcat(
-        Compact.encode(this.length),
+        Compact.encodeU8a(this.length, DEFAULT_LENGTH_BITS),
         encoded
       );
   }

packages/types/src/codec/Compact.spec.js

@@ -8,10 +8,10 @@ import Compact from './Compact';
 import UInt from './UInt';
 
 describe('Compact', () => {
-  describe('encode', () => {
+  describe('encodeU8a', () => {
     it('encodes short u8', () => {
       expect(
-        Compact.encode(18)
+        Compact.encodeU8a(18, 8)
       ).toEqual(
         new Uint8Array([18 << 2])
       );
@@ -19,7 +19,7 @@ describe('Compact', () => {
 
     it('encodes max u8 values', () => {
       expect(
-        Compact.encode(new UInt(63))
+        Compact.encodeU8a(new UInt(63), 16)
       ).toEqual(
         new Uint8Array([0b11111100])
       );
@@ -27,7 +27,7 @@ describe('Compact', () => {
 
     it('encodes basic u16 value', () => {
       expect(
-        Compact.encode(511)
+        Compact.encodeU8a(511, 32)
       ).toEqual(
         new Uint8Array([0b11111101, 0b00000111])
       );
@@ -35,7 +35,7 @@ describe('Compact', () => {
 
     it('encodes basic ua6 (not at edge)', () => {
       expect(
-        Compact.encode(111)
+        Compact.encodeU8a(111, 32)
       ).toEqual(
         new Uint8Array([0xbd, 0x01])
       );
@@ -43,7 +43,7 @@ describe('Compact', () => {
 
     it('encodes basic u32 values (short)', () => {
       expect(
-        Compact.encode(0xffff)
+        Compact.encodeU8a(0xffff, 32)
       ).toEqual(
         new Uint8Array([254, 255, 3, 0])
       );
@@ -51,36 +51,60 @@ describe('Compact', () => {
 
     it('encodes basic u32 values (full)', () => {
       expect(
-        Compact.encode(0xfffffff9)
+        Compact.encodeU8a(0xfffffff9, 32)
       ).toEqual(
         new Uint8Array([3, 249, 255, 255, 255])
       );
     });
   });
 
-  describe('decode', () => {
+  describe('decodeU8a', () => {
     it('decoded u8 value', () => {
       expect(
-        Compact.decode(new Uint8Array([0b11111100]))
+        Compact.decodeU8a(new Uint8Array([0b11111100]), 32)
       ).toEqual([1, new BN(63)]);
     });
 
     it('decodes from same u16 encoded value', () => {
       expect(
-        Compact.decode(new Uint8Array([0b11111101, 0b00000111]))
+        Compact.decodeU8a(new Uint8Array([0b11111101, 0b00000111]), 32)
       ).toEqual([2, new BN(511)]);
     });
 
     it('decodes from same u32 encoded value (short)', () => {
       expect(
-        Compact.decode(new Uint8Array([254, 255, 3, 0]))
+        Compact.decodeU8a(new Uint8Array([254, 255, 3, 0]), 32)
       ).toEqual([4, new BN(0xffff)]);
     });
 
     it('decodes from same u32 encoded value (full)', () => {
       expect(
-        Compact.decode(new Uint8Array([3, 249, 255, 255, 255]))
+        Compact.decodeU8a(new Uint8Array([3, 249, 255, 255, 255]), 32)
       ).toEqual([5, new BN(0xfffffff9)]);
     });
+
+    it('decodes from same u32 as u64 encoded value (full, default)', () => {
+      expect(
+        Compact.decodeU8a(new Uint8Array([3, 249, 255, 255, 255]), 64)
+      ).toEqual([9, new BN(0xfffffff9)]);
+    });
+  });
+
+  it('has the correct byteLength for constructor values (default)', () => {
+    expect(
+      new Compact(0xfffffff9).byteLength()
+    ).toEqual(9);
+  });
+
+  it('has the correct byteLength for constructor values (u32)', () => {
+    expect(
+      new Compact(0xfffffff9, 32).byteLength()
+    ).toEqual(5);
+  });
+
+  it('constructs properly via fromU8a', () => {
+    expect(
+      new Compact().fromU8a(new Uint8Array([254, 255, 3, 0])).raw
+    ).toEqual(new BN(0xffff));
   });
 });

packages/types/src/codec/Compact.ts

@@ -9,15 +9,13 @@ import u8aConcat from '@polkadot/util/u8a/concat';
 import u8aToBn from '@polkadot/util/u8a/toBn';
 import toU8a from '@polkadot/util/u8a/toU8a';
 
-import UInt from './UInt';
+import UInt, { UIntBitLength } from './UInt';
 
-// TODO Could allow for 64 & 128 https://github.com/paritytech/parity-codec/pull/6
-type BitLength = 32;
+export const DEFAULT_LENGTH_BITS = 32;
 
 const MAX_U8 = new BN(2).pow(new BN(8 - 2)).subn(1);
 const MAX_U16 = new BN(2).pow(new BN(16 - 2)).subn(1);
 const MAX_U32 = new BN(2).pow(new BN(32 - 2)).subn(1);
-const DEFAULT_BITLENGTH = 32;
 
 // A new compact length-encoding algorithm. It performs the same function as Length, however
 // differs in that it uses a variable number of bytes to do the actual encoding. From the Rust
@@ -34,8 +32,8 @@ const DEFAULT_BITLENGTH = 32;
 //     nn nn nn 11 [ / zz zz zz zz ]{4 + n}
 //
 // Note: we use *LOW BITS* of the LSB in LE encoding to encode the 2 bit key.
-export default class Compact {
-  static decode (_input: Uint8Array | string, bitLength: BitLength = DEFAULT_BITLENGTH): [number, BN] {
+export default class Compact extends UInt {
+  static decodeU8a (_input: Uint8Array | string, bitLength: UIntBitLength): [number, BN] {
     const input = toU8a(_input);
     const flag = input[0] & 0b11;
 
@@ -52,24 +50,40 @@ export default class Compact {
     return [byteLength + 1, u8aToBn(input.subarray(1, 1 + byteLength), true)];
   }
 
-  static encode (_length: UInt | BN | number, bitLength: BitLength = DEFAULT_BITLENGTH): Uint8Array {
-    const length = _length instanceof UInt
-      ? _length.toBn()
-      : bnToBn(_length);
+  static encodeU8a (_value: UInt | BN | number, bitLength: UIntBitLength): Uint8Array {
+    const value = _value instanceof UInt
+      ? _value.toBn()
+      : bnToBn(_value);
 
-    if (length.lte(MAX_U8)) {
-      return new Uint8Array([length.toNumber() << 2]);
-    } else if (length.lte(MAX_U16)) {
-      return bnToU8a(length.shln(2).addn(0b01), 16, true);
-    } else if (length.lte(MAX_U32)) {
-      return bnToU8a(length.shln(2).addn(0b10), 32, true);
+    if (value.lte(MAX_U8)) {
+      return new Uint8Array([value.toNumber() << 2]);
+    } else if (value.lte(MAX_U16)) {
+      return bnToU8a(value.shln(2).addn(0b01), 16, true);
+    } else if (value.lte(MAX_U32)) {
+      return bnToU8a(value.shln(2).addn(0b10), 32, true);
     }
 
     return u8aConcat(
       new Uint8Array([
         0b11
       ]),
-      bnToU8a(length, bitLength, true)
+      bnToU8a(value, bitLength, true)
     );
   }
+
+  byteLength (): number {
+    return this.toU8a().length;
+  }
+
+  fromU8a (input: Uint8Array): UInt {
+    const [, value] = Compact.decodeU8a(input, this._bitLength);
+
+    this.raw = value;
+
+    return this;
+  }
+
+  toU8a (isBare?: boolean): Uint8Array {
+    return Compact.encodeU8a(this.raw, this._bitLength);
+  }
 }

packages/types/src/codec/UInt.ts

@@ -16,7 +16,9 @@ import u8aToBn from '@polkadot/util/u8a/toBn';
 
 import Base from './Base';
 
-type BitLength = 8 | 16 | 32 | 64 | 128 | 256;
+export type UIntBitLength = 8 | 16 | 32 | 64 | 128 | 256;
+
+export const DEFAULT_UINT_BITS = 64;
 
 // A generic number codec. For Substrate all numbers are LE encoded, this handles the encoding
 // and decoding of those numbers. Upon construction the bitLength is provided and any additional
@@ -25,10 +27,10 @@ type BitLength = 8 | 16 | 32 | 64 | 128 | 256;
 // TODO:
 //   - Apart from encoding/decoding we don't actuall keep check on the sizes, is this good enough?
 export default class UInt extends Base<BN> {
-  private _bitLength: BitLength;
+  protected _bitLength: UIntBitLength;
   private _isHexJson: boolean;
 
-  constructor (value: AnyNumber = 0, bitLength: BitLength = 64, isHexJson: boolean = true) {
+  constructor (value: AnyNumber = 0, bitLength: UIntBitLength = DEFAULT_UINT_BITS, isHexJson: boolean = true) {
     super(
       UInt.decode(value)
     );

packages/types/src/codec/Vector.ts

@@ -5,7 +5,7 @@
 import u8aConcat from '@polkadot/util/u8a/concat';
 
 import Base from './Base';
-import Compact from './Compact';
+import Compact, { DEFAULT_LENGTH_BITS } from './Compact';
 
 // This manages codec arrays. Intrernally it keeps track of the length (as decoded) and allows
 // construction with the passed `Type` in the constructor. It aims to be an array-like structure,
@@ -48,7 +48,7 @@ export default class Vector <
   byteLength (): number {
     return this.raw.reduce((total, raw) => {
       return total + raw.byteLength();
-    }, Compact.encode(this.length).length);
+    }, Compact.encodeU8a(this.length, DEFAULT_LENGTH_BITS).length);
   }
 
   filter (fn: (item: T, index?: number) => any): Array<T> {
@@ -72,7 +72,7 @@ export default class Vector <
   }
 
   fromU8a (input: Uint8Array): Vector<T> {
-    let [offset, _length] = Compact.decode(input);
+    let [offset, _length] = Compact.decodeU8a(input, DEFAULT_LENGTH_BITS);
     const length = _length.toNumber();
 
     this.raw = [];
@@ -117,7 +117,7 @@ export default class Vector <
     return isBare
       ? u8aConcat(...encoded)
       : u8aConcat(
-        Compact.encode(this.length),
+        Compact.encodeU8a(this.length, DEFAULT_LENGTH_BITS),
         ...encoded
       );
   }

packages/types/src/index.ts

@@ -18,6 +18,11 @@ export { default as Block } from './Block';
 export { default as BlockNumber } from './BlockNumber';
 export { default as Bool } from './Bool';
 export { default as Bytes } from './Bytes';
+export { default as Compact16 } from './Compact16';
+export { default as Compact32 } from './Compact32';
+export { default as Compact64 } from './Compact64';
+export { default as Compact128 } from './Compact128';
+export { default as Compact256 } from './Compact256';
 export { default as Extrinsic } from './Extrinsic';
 export { default as ExtrinsicEra } from './ExtrinsicEra';
 export { default as ExtrinsicSignature } from './ExtrinsicSignature';