52 lines
1.1 KiB
Plaintext
52 lines
1.1 KiB
Plaintext
function byteLength (string) {
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return string.length >>> 1
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}
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function toString (buffer) {
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const len = buffer.byteLength
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buffer = new DataView(buffer.buffer, buffer.byteOffset, len)
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let result = ''
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let i = 0
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for (let n = len - (len % 4); i < n; i += 4) {
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result += buffer.getUint32(i).toString(16).padStart(8, '0')
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}
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for (; i < len; i++) {
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result += buffer.getUint8(i).toString(16).padStart(2, '0')
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}
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return result
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}
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function write (buffer, string, offset = 0, length = byteLength(string)) {
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const len = Math.min(length, buffer.byteLength - offset)
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for (let i = 0; i < len; i++) {
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const a = hexValue(string.charCodeAt(i * 2))
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const b = hexValue(string.charCodeAt(i * 2 + 1))
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if (a === undefined || b === undefined) {
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return buffer.subarray(0, i)
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}
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buffer[offset + i] = (a << 4) | b
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}
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return len
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}
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module.exports = {
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byteLength,
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toString,
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write
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}
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function hexValue (char) {
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if (char >= 0x30 && char <= 0x39) return char - 0x30
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if (char >= 0x41 && char <= 0x46) return char - 0x41 + 10
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if (char >= 0x61 && char <= 0x66) return char - 0x61 + 10
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}
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