a collection of lightweight TypeScript packages for AT Protocol, the protocol powering Bluesky
atproto
bluesky
typescript
npm
refactor(tid): inline s32 decode directly
+24
-16
+4
packages/utilities/tid/lib/index.test.ts
+4
packages/utilities/tid/lib/index.test.ts
+19
-4
packages/utilities/tid/lib/index.ts
+19
-4
packages/utilities/tid/lib/index.ts
···
2
2
3
3
import { random } from '#platform/random';
4
4
5
-
import { S32_2CHAR_TABLE, s32decode, s32encode } from './s32.ts';
5
+
import { S32_2CHAR_TABLE, S32_DECODE_TABLE, s32encode } from './s32.ts';
6
6
7
7
let lastTimestamp = 0;
8
8
let lastCurrentTime = 0;
···
55
55
* Parses a TID, throws on invalid strings.
56
56
*/
57
57
export const parse = (tid: string): { timestamp: number; clockid: number } => {
58
-
if (!validate(tid)) {
58
+
if (tid.length !== 13) {
59
59
throw new Error(`invalid TID`);
60
60
}
61
61
62
-
const timestamp = s32decode(tid, 0, 11);
63
-
const clockid = s32decode(tid, 11, 2);
62
+
let timestamp = 0;
63
+
let clockid = 0;
64
+
65
+
for (let idx = 0; idx < 13; idx++) {
66
+
const code = tid.charCodeAt(idx);
67
+
const value = code < S32_DECODE_TABLE.length ? S32_DECODE_TABLE[code]! : -1;
68
+
69
+
if (value < 0 || (idx === 0 && value > 15)) {
70
+
throw new Error(`invalid TID`);
71
+
}
72
+
73
+
if (idx < 11) {
74
+
timestamp = timestamp * 32 + value;
75
+
} else {
76
+
clockid = clockid * 32 + value;
77
+
}
78
+
}
64
79
65
80
return { timestamp, clockid };
66
81
};
+1
-12
packages/utilities/tid/lib/s32.ts
+1
-12
packages/utilities/tid/lib/s32.ts
···
1
1
const S32_CHAR = '234567abcdefghijklmnopqrstuvwxyz';
2
2
3
-
const S32_DECODE_TABLE = /*#__PURE__*/ (() => {
3
+
export const S32_DECODE_TABLE = /*#__PURE__*/ (() => {
4
4
const table = new Int16Array(123);
5
5
table.fill(-1);
6
6
···
35
35
36
36
return s;
37
37
};
38
-
39
-
export const s32decode = (s: string, offset: number, length: number): number => {
40
-
let i = 0;
41
-
const end = offset + length;
42
-
43
-
for (let idx = offset; idx < end; idx++) {
44
-
i = i * 32 + S32_DECODE_TABLE[s.charCodeAt(idx)]!;
45
-
}
46
-
47
-
return i;
48
-
};