0d073fa89e
- Add GETTING_STARTED.md with quick start guide and development modes - Add INSTALL.sh automated installation script - Add INSTALLATION_CHECKLIST.md, INSTALLATION_SUCCESS.md, and INSTALLATION_SUMMARY.md - Add QUICK_REFERENCE.md for common commands - Add SETUP_GUIDE.md with detailed setup instructions - Update README.md with improved project overview - Add did-wallet app dependencies and node_modules
123 lines
3.5 KiB
JavaScript
123 lines
3.5 KiB
JavaScript
const SURROGATE_A = 0b1101100000000000
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const SURROGATE_B = 0b1101110000000000
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export const name = 'utf8'
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export function encodingLength (str) {
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let len = 0
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const strLen = str.length
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for (let i = 0; i < strLen; i += 1) {
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const code = str.charCodeAt(i)
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if (code <= 0x7F) {
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len += 1
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} else if (code <= 0x07FF) {
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len += 2
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} else if ((code & 0xF800) !== SURROGATE_A) {
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len += 3
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} else {
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const next = i + 1
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if (next === strLen || code >= SURROGATE_B) {
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len += 3
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} else {
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const nextCode = str.charCodeAt(next)
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if ((nextCode & 0xFC00) !== SURROGATE_B) {
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len += 3
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} else {
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i = next
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len += 4
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}
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}
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}
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}
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return len
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}
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export function encode (str, buf, offset) {
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const strLen = str.length
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if (offset === undefined || offset === null) {
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offset = 0
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}
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if (buf === undefined) {
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buf = new Uint8Array(encodingLength(str) + offset)
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}
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let off = offset
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for (let i = 0; i < strLen; i += 1) {
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let code = str.charCodeAt(i)
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if (code <= 0x7F) {
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buf[off++] = code
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} else if (code <= 0x07FF) {
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buf[off++] = 0b11000000 | ((code & 0b11111000000) >> 6)
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buf[off++] = 0b10000000 | (code & 0b00000111111)
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} else if ((code & 0xF800) !== SURROGATE_A) {
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buf[off++] = 0b11100000 | ((code & 0b1111000000000000) >> 12)
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buf[off++] = 0b10000000 | ((code & 0b0000111111000000) >> 6)
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buf[off++] = 0b10000000 | (code & 0b0000000000111111)
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} else {
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const next = i + 1
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if (next === strLen || code >= SURROGATE_B) {
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// Incorrectly started surrogate pair
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buf[off++] = 0xef
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buf[off++] = 0xbf
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buf[off++] = 0xbd
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} else {
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const nextCode = str.charCodeAt(next)
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if ((nextCode & 0xFC00) !== SURROGATE_B) {
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// Incorrect surrogate pair
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buf[off++] = 0xef
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buf[off++] = 0xbf
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buf[off++] = 0xbd
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} else {
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i = next
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code = 0b000010000000000000000 |
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((code & 0b1111111111) << 10) |
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(nextCode & 0b1111111111)
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buf[off++] = 0b11110000 | ((code & 0b111000000000000000000) >> 18)
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buf[off++] = 0b10000000 | ((code & 0b000111111000000000000) >> 12)
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buf[off++] = 0b10000000 | ((code & 0b000000000111111000000) >> 6)
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buf[off++] = 0b10000000 | (code & 0b000000000000000111111)
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}
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}
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}
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}
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encode.bytes = off - offset
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return buf
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}
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encode.bytes = 0
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export function decode (buf, start, end) {
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let result = ''
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if (start === undefined || start === null) {
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start = 0
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}
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if (end === undefined || end === null) {
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end = buf.length
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}
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for (let offset = start; offset < end;) {
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const code = buf[offset++]
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let num
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if (code <= 128) {
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num = code
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} else if (code > 191 && code < 224) {
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num = ((code & 0b11111) << 6) | (buf[offset++] & 0b111111)
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} else if (code > 239 && code < 365) {
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num = (
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((code & 0b111) << 18) |
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((buf[offset++] & 0b111111) << 12) |
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((buf[offset++] & 0b111111) << 6) |
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(buf[offset++] & 0b111111)
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) - 0x10000
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const numA = SURROGATE_A | ((num >> 10) & 0b1111111111)
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result += String.fromCharCode(numA)
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num = SURROGATE_B | (num & 0b1111111111)
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} else {
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num = ((code & 0b1111) << 12) |
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((buf[offset++] & 0b111111) << 6) |
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(buf[offset++] & 0b111111)
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}
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result += String.fromCharCode(num)
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}
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decode.bytes = end - start
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return result
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}
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decode.bytes = 0
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