44 lines
1.3 KiB
JavaScript
44 lines
1.3 KiB
JavaScript
export const encoder = new TextEncoder();
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export const decoder = new TextDecoder();
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const MAX_INT32 = 2 ** 32;
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export function concat(...buffers) {
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const size = buffers.reduce((acc, { length }) => acc + length, 0);
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const buf = new Uint8Array(size);
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let i = 0;
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for (const buffer of buffers) {
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buf.set(buffer, i);
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i += buffer.length;
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}
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return buf;
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}
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function writeUInt32BE(buf, value, offset) {
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if (value < 0 || value >= MAX_INT32) {
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throw new RangeError(`value must be >= 0 and <= ${MAX_INT32 - 1}. Received ${value}`);
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}
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buf.set([value >>> 24, value >>> 16, value >>> 8, value & 0xff], offset);
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}
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export function uint64be(value) {
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const high = Math.floor(value / MAX_INT32);
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const low = value % MAX_INT32;
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const buf = new Uint8Array(8);
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writeUInt32BE(buf, high, 0);
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writeUInt32BE(buf, low, 4);
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return buf;
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}
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export function uint32be(value) {
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const buf = new Uint8Array(4);
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writeUInt32BE(buf, value);
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return buf;
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}
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export function encode(string) {
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const bytes = new Uint8Array(string.length);
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for (let i = 0; i < string.length; i++) {
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const code = string.charCodeAt(i);
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if (code > 127) {
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throw new TypeError('non-ASCII string encountered in encode()');
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}
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bytes[i] = code;
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}
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return bytes;
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}
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