Viewing File: /home/ubuntu/misabloom-frontend-base/node_modules/@ethersproject/strings/src.ts/utf8.ts
"use strict";
import { arrayify, BytesLike } from "@ethersproject/bytes";
import { Logger } from "@ethersproject/logger";
import { version } from "./_version";
const logger = new Logger(version);
///////////////////////////////
export enum UnicodeNormalizationForm {
current = "",
NFC = "NFC",
NFD = "NFD",
NFKC = "NFKC",
NFKD = "NFKD"
};
export enum Utf8ErrorReason {
// A continuation byte was present where there was nothing to continue
// - offset = the index the codepoint began in
UNEXPECTED_CONTINUE = "unexpected continuation byte",
// An invalid (non-continuation) byte to start a UTF-8 codepoint was found
// - offset = the index the codepoint began in
BAD_PREFIX = "bad codepoint prefix",
// The string is too short to process the expected codepoint
// - offset = the index the codepoint began in
OVERRUN = "string overrun",
// A missing continuation byte was expected but not found
// - offset = the index the continuation byte was expected at
MISSING_CONTINUE = "missing continuation byte",
// The computed code point is outside the range for UTF-8
// - offset = start of this codepoint
// - badCodepoint = the computed codepoint; outside the UTF-8 range
OUT_OF_RANGE = "out of UTF-8 range",
// UTF-8 strings may not contain UTF-16 surrogate pairs
// - offset = start of this codepoint
// - badCodepoint = the computed codepoint; inside the UTF-16 surrogate range
UTF16_SURROGATE = "UTF-16 surrogate",
// The string is an overlong representation
// - offset = start of this codepoint
// - badCodepoint = the computed codepoint; already bounds checked
OVERLONG = "overlong representation",
};
export type Utf8ErrorFunc = (reason: Utf8ErrorReason, offset: number, bytes: ArrayLike<number>, output: Array<number>, badCodepoint?: number) => number;
function errorFunc(reason: Utf8ErrorReason, offset: number, bytes: ArrayLike<number>, output: Array<number>, badCodepoint?: number): number {
return logger.throwArgumentError(`invalid codepoint at offset ${ offset }; ${ reason }`, "bytes", bytes);
}
function ignoreFunc(reason: Utf8ErrorReason, offset: number, bytes: ArrayLike<number>, output: Array<number>, badCodepoint?: number): number {
// If there is an invalid prefix (including stray continuation), skip any additional continuation bytes
if (reason === Utf8ErrorReason.BAD_PREFIX || reason === Utf8ErrorReason.UNEXPECTED_CONTINUE) {
let i = 0;
for (let o = offset + 1; o < bytes.length; o++) {
if (bytes[o] >> 6 !== 0x02) { break; }
i++;
}
return i;
}
// This byte runs us past the end of the string, so just jump to the end
// (but the first byte was read already read and therefore skipped)
if (reason === Utf8ErrorReason.OVERRUN) {
return bytes.length - offset - 1;
}
// Nothing to skip
return 0;
}
function replaceFunc(reason: Utf8ErrorReason, offset: number, bytes: ArrayLike<number>, output: Array<number>, badCodepoint?: number): number {
// Overlong representations are otherwise "valid" code points; just non-deistingtished
if (reason === Utf8ErrorReason.OVERLONG) {
output.push(badCodepoint);
return 0;
}
// Put the replacement character into the output
output.push(0xfffd);
// Otherwise, process as if ignoring errors
return ignoreFunc(reason, offset, bytes, output, badCodepoint);
}
// Common error handing strategies
export const Utf8ErrorFuncs: { [ name: string ]: Utf8ErrorFunc } = Object.freeze({
error: errorFunc,
ignore: ignoreFunc,
replace: replaceFunc
});
// http://stackoverflow.com/questions/13356493/decode-utf-8-with-javascript#13691499
function getUtf8CodePoints(bytes: BytesLike, onError?: Utf8ErrorFunc): Array<number> {
if (onError == null) { onError = Utf8ErrorFuncs.error; }
bytes = arrayify(bytes);
const result: Array<number> = [];
let i = 0;
// Invalid bytes are ignored
while(i < bytes.length) {
const c = bytes[i++];
// 0xxx xxxx
if (c >> 7 === 0) {
result.push(c);
continue;
}
// Multibyte; how many bytes left for this character?
let extraLength = null;
let overlongMask = null;
// 110x xxxx 10xx xxxx
if ((c & 0xe0) === 0xc0) {
extraLength = 1;
overlongMask = 0x7f;
// 1110 xxxx 10xx xxxx 10xx xxxx
} else if ((c & 0xf0) === 0xe0) {
extraLength = 2;
overlongMask = 0x7ff;
// 1111 0xxx 10xx xxxx 10xx xxxx 10xx xxxx
} else if ((c & 0xf8) === 0xf0) {
extraLength = 3;
overlongMask = 0xffff;
} else {
if ((c & 0xc0) === 0x80) {
i += onError(Utf8ErrorReason.UNEXPECTED_CONTINUE, i - 1, bytes, result);
} else {
i += onError(Utf8ErrorReason.BAD_PREFIX, i - 1, bytes, result);
}
continue;
}
// Do we have enough bytes in our data?
if (i - 1 + extraLength >= bytes.length) {
i += onError(Utf8ErrorReason.OVERRUN, i - 1, bytes, result);
continue;
}
// Remove the length prefix from the char
let res = c & ((1 << (8 - extraLength - 1)) - 1);
for (let j = 0; j < extraLength; j++) {
let nextChar = bytes[i];
// Invalid continuation byte
if ((nextChar & 0xc0) != 0x80) {
i += onError(Utf8ErrorReason.MISSING_CONTINUE, i, bytes, result);
res = null;
break;
};
res = (res << 6) | (nextChar & 0x3f);
i++;
}
// See above loop for invalid continuation byte
if (res === null) { continue; }
// Maximum code point
if (res > 0x10ffff) {
i += onError(Utf8ErrorReason.OUT_OF_RANGE, i - 1 - extraLength, bytes, result, res);
continue;
}
// Reserved for UTF-16 surrogate halves
if (res >= 0xd800 && res <= 0xdfff) {
i += onError(Utf8ErrorReason.UTF16_SURROGATE, i - 1 - extraLength, bytes, result, res);
continue;
}
// Check for overlong sequences (more bytes than needed)
if (res <= overlongMask) {
i += onError(Utf8ErrorReason.OVERLONG, i - 1 - extraLength, bytes, result, res);
continue;
}
result.push(res);
}
return result;
}
// http://stackoverflow.com/questions/18729405/how-to-convert-utf8-string-to-byte-array
export function toUtf8Bytes(str: string, form: UnicodeNormalizationForm = UnicodeNormalizationForm.current): Uint8Array {
if (form != UnicodeNormalizationForm.current) {
logger.checkNormalize();
str = str.normalize(form);
}
let result = [];
for (let i = 0; i < str.length; i++) {
const c = str.charCodeAt(i);
if (c < 0x80) {
result.push(c);
} else if (c < 0x800) {
result.push((c >> 6) | 0xc0);
result.push((c & 0x3f) | 0x80);
} else if ((c & 0xfc00) == 0xd800) {
i++;
const c2 = str.charCodeAt(i);
if (i >= str.length || (c2 & 0xfc00) !== 0xdc00) {
throw new Error("invalid utf-8 string");
}
// Surrogate Pair
const pair = 0x10000 + ((c & 0x03ff) << 10) + (c2 & 0x03ff);
result.push((pair >> 18) | 0xf0);
result.push(((pair >> 12) & 0x3f) | 0x80);
result.push(((pair >> 6) & 0x3f) | 0x80);
result.push((pair & 0x3f) | 0x80);
} else {
result.push((c >> 12) | 0xe0);
result.push(((c >> 6) & 0x3f) | 0x80);
result.push((c & 0x3f) | 0x80);
}
}
return arrayify(result);
};
function escapeChar(value: number) {
const hex = ("0000" + value.toString(16));
return "\\u" + hex.substring(hex.length - 4);
}
export function _toEscapedUtf8String(bytes: BytesLike, onError?: Utf8ErrorFunc): string {
return '"' + getUtf8CodePoints(bytes, onError).map((codePoint) => {
if (codePoint < 256) {
switch (codePoint) {
case 8: return "\\b";
case 9: return "\\t";
case 10: return "\\n"
case 13: return "\\r";
case 34: return "\\\"";
case 92: return "\\\\";
}
if (codePoint >= 32 && codePoint < 127) {
return String.fromCharCode(codePoint);
}
}
if (codePoint <= 0xffff) {
return escapeChar(codePoint);
}
codePoint -= 0x10000;
return escapeChar(((codePoint >> 10) & 0x3ff) + 0xd800) + escapeChar((codePoint & 0x3ff) + 0xdc00);
}).join("") + '"';
}
export function _toUtf8String(codePoints: Array<number>): string {
return codePoints.map((codePoint) => {
if (codePoint <= 0xffff) {
return String.fromCharCode(codePoint);
}
codePoint -= 0x10000;
return String.fromCharCode(
(((codePoint >> 10) & 0x3ff) + 0xd800),
((codePoint & 0x3ff) + 0xdc00)
);
}).join("");
}
export function toUtf8String(bytes: BytesLike, onError?: Utf8ErrorFunc): string {
return _toUtf8String(getUtf8CodePoints(bytes, onError));
}
export function toUtf8CodePoints(str: string, form: UnicodeNormalizationForm = UnicodeNormalizationForm.current): Array<number> {
return getUtf8CodePoints(toUtf8Bytes(str, form));
}
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