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- "use strict";
- Object.defineProperty(exports, "__esModule", { value: true });
- exports.toUtf8CodePoints = exports.toUtf8String = exports.toUtf8Bytes = exports.Utf8ErrorFuncs = void 0;
- /**
- * Using strings in Ethereum (or any security-basd system) requires
- * additional care. These utilities attempt to mitigate some of the
- * safety issues as well as provide the ability to recover and analyse
- * strings.
- *
- * @_subsection api/utils:Strings and UTF-8 [about-strings]
- */
- const data_js_1 = require("./data.js");
- const errors_js_1 = require("./errors.js");
- function errorFunc(reason, offset, bytes, output, badCodepoint) {
- (0, errors_js_1.assertArgument)(false, `invalid codepoint at offset ${offset}; ${reason}`, "bytes", bytes);
- }
- function ignoreFunc(reason, offset, bytes, output, badCodepoint) {
- // If there is an invalid prefix (including stray continuation), skip any additional continuation bytes
- if (reason === "BAD_PREFIX" || reason === "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 === "OVERRUN") {
- return bytes.length - offset - 1;
- }
- // Nothing to skip
- return 0;
- }
- function replaceFunc(reason, offset, bytes, output, badCodepoint) {
- // Overlong representations are otherwise "valid" code points; just non-deistingtished
- if (reason === "OVERLONG") {
- (0, errors_js_1.assertArgument)(typeof (badCodepoint) === "number", "invalid bad code point for replacement", "badCodepoint", badCodepoint);
- 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);
- }
- /**
- * A handful of popular, built-in UTF-8 error handling strategies.
- *
- * **``"error"``** - throws on ANY illegal UTF-8 sequence or
- * non-canonical (overlong) codepoints (this is the default)
- *
- * **``"ignore"``** - silently drops any illegal UTF-8 sequence
- * and accepts non-canonical (overlong) codepoints
- *
- * **``"replace"``** - replace any illegal UTF-8 sequence with the
- * UTF-8 replacement character (i.e. ``"\\ufffd"``) and accepts
- * non-canonical (overlong) codepoints
- *
- * @returns: Record<"error" | "ignore" | "replace", Utf8ErrorFunc>
- */
- exports.Utf8ErrorFuncs = Object.freeze({
- error: errorFunc,
- ignore: ignoreFunc,
- replace: replaceFunc
- });
- // http://stackoverflow.com/questions/13356493/decode-utf-8-with-javascript#13691499
- function getUtf8CodePoints(_bytes, onError) {
- if (onError == null) {
- onError = exports.Utf8ErrorFuncs.error;
- }
- const bytes = (0, data_js_1.getBytes)(_bytes, "bytes");
- const result = [];
- 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("UNEXPECTED_CONTINUE", i - 1, bytes, result);
- }
- else {
- i += onError("BAD_PREFIX", i - 1, bytes, result);
- }
- continue;
- }
- // Do we have enough bytes in our data?
- if (i - 1 + extraLength >= bytes.length) {
- i += onError("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("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("OUT_OF_RANGE", i - 1 - extraLength, bytes, result, res);
- continue;
- }
- // Reserved for UTF-16 surrogate halves
- if (res >= 0xd800 && res <= 0xdfff) {
- i += onError("UTF16_SURROGATE", i - 1 - extraLength, bytes, result, res);
- continue;
- }
- // Check for overlong sequences (more bytes than needed)
- if (res <= overlongMask) {
- i += onError("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
- /**
- * Returns the UTF-8 byte representation of %%str%%.
- *
- * If %%form%% is specified, the string is normalized.
- */
- function toUtf8Bytes(str, form) {
- (0, errors_js_1.assertArgument)(typeof (str) === "string", "invalid string value", "str", str);
- if (form != null) {
- (0, errors_js_1.assertNormalize)(form);
- 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);
- (0, errors_js_1.assertArgument)(i < str.length && ((c2 & 0xfc00) === 0xdc00), "invalid surrogate pair", "str", str);
- // 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 new Uint8Array(result);
- }
- exports.toUtf8Bytes = toUtf8Bytes;
- ;
- //export
- function _toUtf8String(codePoints) {
- return codePoints.map((codePoint) => {
- if (codePoint <= 0xffff) {
- return String.fromCharCode(codePoint);
- }
- codePoint -= 0x10000;
- return String.fromCharCode((((codePoint >> 10) & 0x3ff) + 0xd800), ((codePoint & 0x3ff) + 0xdc00));
- }).join("");
- }
- /**
- * Returns the string represented by the UTF-8 data %%bytes%%.
- *
- * When %%onError%% function is specified, it is called on UTF-8
- * errors allowing recovery using the [[Utf8ErrorFunc]] API.
- * (default: [error](Utf8ErrorFuncs))
- */
- function toUtf8String(bytes, onError) {
- return _toUtf8String(getUtf8CodePoints(bytes, onError));
- }
- exports.toUtf8String = toUtf8String;
- /**
- * Returns the UTF-8 code-points for %%str%%.
- *
- * If %%form%% is specified, the string is normalized.
- */
- function toUtf8CodePoints(str, form) {
- return getUtf8CodePoints(toUtf8Bytes(str, form));
- }
- exports.toUtf8CodePoints = toUtf8CodePoints;
- //# sourceMappingURL=utf8.js.map
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