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jtennerjtenner
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[implement] rudimentary base64
1 parent e3e6b3a commit edace6b

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3 files changed

+108
-1
lines changed

3 files changed

+108
-1
lines changed

‎assembly/buffer/index.ts‎

Lines changed: 68 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -376,4 +376,72 @@ export namespace Buffer {
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return changetype<string>(result);
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}
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}
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export namespace BASE64 {
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function charCodeFromByte(value: i32): u64 {
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if (i32(value >= 0) & i32(value < 26)) return value + 0x41;
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else if (i32(value >= 26) & i32(value < 51)) return value + 0x61;
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else return select(0x2B, 0x2F, value == 62);
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}
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export function byteLength(input: string): i32 {
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return -1;
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}
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export function stringLength(buffer: ArrayBuffer): i32 {
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return <i32>Math.ceil(<f32>buffer.byteLength / 3) << 2;
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}
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export function encode(input: string): ArrayBuffer {
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return new ArrayBuffer(0);
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}
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export function decode(buffer: ArrayBuffer): string {
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return decodeUnsafe(changetype<usize>(buffer), buffer.byteLength);
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}
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export function decodeUnsafe(pointer: usize, length: i32): string {
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if (length == 0) return "";
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let iterations = <i32>Math.floor(length / 3);
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let leftoverBytes = length % 3;
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let stringLength = (iterations << 2) + select(4, 0, leftoverBytes);
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let output = __alloc(stringLength << 1, idof<String>());
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for (let i = 0; i < iterations; i++) {
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let bytes = bswap<u32>(load<u32>(pointer + <usize>i * 3)) >>> 8;
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let value1 = (bytes & 0b111111000000000000000000) >> 18; // first 6 bits
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let value2 = (bytes & 0b111111000000000000) >> 12; // second 6 bits
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let value3 = (bytes & 0b111111000000) >> 6 ; // third 6 bits
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let value4 = (bytes & 0b111111) ; // fourth 6 bits
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let chars: u64 = charCodeFromByte(value1)
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| (charCodeFromByte(value2) << 16)
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| (charCodeFromByte(value3) << 32)
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| (charCodeFromByte(value4) << 48);
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store<u64>(output + (<usize>i << alignof<u64>()), chars);
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}
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// A is 0x61
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// = is 0x3D
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if (leftoverBytes == 2) {
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let bytes = <u32>bswap<u16>(load<u16>(pointer + <usize>(iterations * 3))) << 2;
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let value1 = (bytes & 0b111111000000000000) >> 12; // first 6 bits
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let value2 = (bytes & 0b111111000000) >> 6 ; // second 6 bits
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let value3 = (bytes & 0b111111) >> 0 ; // third 6 bits
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let chars: u64 = charCodeFromByte(value1)
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| <u64>(charCodeFromByte(value2) << 16)
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| <u64>(charCodeFromByte(value3) << 32)
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| <u64>0x3D000000000000;
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store<u64>(output + (<usize>iterations << alignof<u64>()), chars);
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} else if (leftoverBytes == 1) {
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let bytes = <i32>load<u8>(pointer + <usize>(iterations * 3)) >> 2;
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let chars: u64 = charCodeFromByte(bytes & 0b111111)
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| <u64>0x3D003D00410000;
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store<u64>(output + (<usize>iterations << alignof<u64>()), chars);
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}
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return changetype<string>(output);
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}
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}
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}

‎index.js‎

Lines changed: 7 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,7 @@
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const { randomFillSync } = require("crypto");
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for (let i = 0; i < 10; i++) {
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let buffer = randomFillSync(Buffer.allocUnsafe(Math.floor(Math.random() * 100)));
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let result = buffer.toString("base64");
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console.log(Array.from(buffer), result);
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}

‎tests/buffer.spec.ts‎

Lines changed: 33 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -570,7 +570,7 @@ describe("buffer", () => {
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// newBuff.swap64();
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// }).toThrow();
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});
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test("#Hex.encode", () => {
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let actual = "000102030405060708090a0b0c0d0e0f102030405060708090a0b0c0d0e0f0";
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let exampleBuffer = create<Buffer>([0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, 0x80, 0x90, 0xa0, 0xb0, 0xc0, 0xd0, 0xe0, 0xf0]);
@@ -584,4 +584,36 @@ describe("buffer", () => {
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let decoded = Buffer.HEX.decode(exampleBuffer.buffer);
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expect<string>(decoded).toStrictEqual(expected);
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});
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test("#Base64.decode", () => {
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let decoded = Buffer.BASE64.decode(create<Buffer>([1, 2, 3]).buffer);
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expect<string>(decoded).toBe("AQID");
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decoded = Buffer.BASE64.decode(create<Buffer>([1, 2, 3, 4]).buffer);
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expect<string>(decoded).toStrictEqual("AQIDBA==");
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decoded = Buffer.BASE64.decode(create<Buffer>([1, 2, 3, 4, 5]).buffer);
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expect<string>(decoded).toBe("AQIDBAU=", "target");
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decoded = Buffer.BASE64.decode(create<Buffer>([
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150, 144, 40, 36, 82, 6, 240, 81, 182, 94, 22,
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137, 32, 212, 14, 6, 176, 169, 104, 91, 243, 241,
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62, 242, 156, 72, 51, 139, 140, 227, 109, 204, 147,
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130, 35, 104, 157, 139, 52, 201, 114, 154, 160, 230,
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185, 245, 198, 192, 21, 153, 33, 120, 133, 40, 140,
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215, 26, 233, 199, 245, 13, 211, 169, 183
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]).buffer);
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expect<string>(decoded).toBe("lpAoJFIG8FG2XhaJINQOBrCpaFvz8T7ynEgzi4zjbcyTgiNonYs0yXKaoOa59cbAFZkheIUojNca6cf1DdOptw==");
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decoded = Buffer.BASE64.decode(create<Buffer>([
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189, 36, 9, 30, 61, 86, 186, 198, 247, 150, 23, 224,
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108, 178, 35, 223, 155, 242, 140, 171, 163, 130, 173, 126,
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60, 70, 83, 211, 113, 6, 137, 140, 166, 98, 94, 94,
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4, 110, 146, 2, 226, 51, 123, 226, 235, 4, 44, 31,
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113, 69, 169, 100, 97, 170, 239, 185, 119, 106, 112, 107,
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162, 44, 211, 166, 88, 225, 141, 38, 122, 82, 229, 153,
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115, 23, 108, 119, 38, 17, 228, 204, 52, 14, 27, 104,
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59, 64, 197, 109, 235, 206, 243, 196, 171, 179, 6, 62,
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106
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]).buffer);
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expect<string>(decoded).toBe("vSQJHj1Wusb3lhfgbLIj35vyjKujgq1+PEZT03EGiYymYl5eBG6SAuIze+LrBCwfcUWpZGGq77l3anBroizTpljhjSZ6UuWZcxdsdyYR5Mw0DhtoO0DFbevO88SrswY+ag==");
618+
});
587619
});

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