66 lines
2.1 KiB
JavaScript
66 lines
2.1 KiB
JavaScript
import rng from './rng.js';
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import { unsafeStringify } from './stringify.js';
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const _state = {};
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function v7(options, buf, offset) {
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let bytes;
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if (options) {
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bytes = v7Bytes(options.random ?? options.rng?.() ?? rng(), options.msecs, options.seq, buf, offset);
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}
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else {
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const now = Date.now();
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const rnds = rng();
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updateV7State(_state, now, rnds);
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bytes = v7Bytes(rnds, _state.msecs, _state.seq, buf, offset);
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}
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return buf ?? unsafeStringify(bytes);
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}
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export function updateV7State(state, now, rnds) {
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state.msecs ??= -Infinity;
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state.seq ??= 0;
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if (now > state.msecs) {
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state.seq = (rnds[6] << 23) | (rnds[7] << 16) | (rnds[8] << 8) | rnds[9];
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state.msecs = now;
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}
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else {
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state.seq = (state.seq + 1) | 0;
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if (state.seq === 0) {
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state.msecs++;
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}
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}
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return state;
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}
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function v7Bytes(rnds, msecs, seq, buf, offset = 0) {
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if (rnds.length < 16) {
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throw new Error('Random bytes length must be >= 16');
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}
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if (!buf) {
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buf = new Uint8Array(16);
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offset = 0;
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}
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else {
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if (offset < 0 || offset + 16 > buf.length) {
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throw new RangeError(`UUID byte range ${offset}:${offset + 15} is out of buffer bounds`);
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}
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}
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msecs ??= Date.now();
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seq ??= ((rnds[6] * 0x7f) << 24) | (rnds[7] << 16) | (rnds[8] << 8) | rnds[9];
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buf[offset++] = (msecs / 0x10000000000) & 0xff;
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buf[offset++] = (msecs / 0x100000000) & 0xff;
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buf[offset++] = (msecs / 0x1000000) & 0xff;
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buf[offset++] = (msecs / 0x10000) & 0xff;
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buf[offset++] = (msecs / 0x100) & 0xff;
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buf[offset++] = msecs & 0xff;
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buf[offset++] = 0x70 | ((seq >>> 28) & 0x0f);
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buf[offset++] = (seq >>> 20) & 0xff;
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buf[offset++] = 0x80 | ((seq >>> 14) & 0x3f);
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buf[offset++] = (seq >>> 6) & 0xff;
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buf[offset++] = ((seq << 2) & 0xff) | (rnds[10] & 0x03);
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buf[offset++] = rnds[11];
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buf[offset++] = rnds[12];
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buf[offset++] = rnds[13];
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buf[offset++] = rnds[14];
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buf[offset++] = rnds[15];
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return buf;
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}
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export default v7;
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