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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
export var MailStringUtils = {
/**
* Convert a ByteString to a Uint8Array.
*
* @param {ByteString} str - The input string.
* @returns {Uint8Array} The output Uint8Array.
*/
byteStringToUint8Array(str) {
const arr = new Uint8Array(str.length);
for (let i = 0; i < str.length; i++) {
arr[i] = str.charCodeAt(i);
}
return arr;
},
/**
* Convert a Uint8Array to a ByteString.
*
* @param {Uint8Array} arr - The input Uint8Array.
* @returns {ByteString} The output string.
*/
uint8ArrayToByteString(arr) {
let str = "";
for (let i = 0; i < arr.length; i += 65536) {
str += String.fromCharCode.apply(null, arr.subarray(i, i + 65536));
}
return str;
},
/**
* Convert a ByteString to a string.
*
* @param {ByteString} str - The ByteString to convert.
* @param {string} [charset="utf-8"] - The charset the string was in.
* @returns {string} The converted string.
*/
byteStringToString(str, charset = "utf-8") {
return new TextDecoder(charset).decode(this.byteStringToUint8Array(str));
},
/**
* Convert a string to a ByteString.
*
* @param {string} str - The string to convert.
* @returns {ByteString} The converted ByteString.
*/
stringToByteString(str) {
return this.uint8ArrayToByteString(new TextEncoder().encode(str));
},
/**
* Detect the text encoding of a ByteString.
*
* @param {ByteString} str - The input string.
* @returns {string} The output charset name.
*/
detectCharset(str) {
// Check the BOM.
let charset = "";
if (str.length >= 2) {
const byte0 = str.charCodeAt(0);
const byte1 = str.charCodeAt(1);
const byte2 = str.charCodeAt(2);
if (byte0 == 0xfe && byte1 == 0xff) {
charset = "UTF-16BE";
} else if (byte0 == 0xff && byte1 == 0xfe) {
charset = "UTF-16LE";
} else if (byte0 == 0xef && byte1 == 0xbb && byte2 == 0xbf) {
charset = "UTF-8";
}
}
if (charset) {
return charset;
}
// Use mozilla::EncodingDetector.
const compUtils = Cc[
"@mozilla.org/messengercompose/computils;1"
].createInstance(Ci.nsIMsgCompUtils);
return compUtils.detectCharset(str);
},
/**
* Read and detect the charset of a file, then convert the file content to
* DOMString. If you're absolutely sure it's a UTF-8 encoded file, use
* IOUtils.readUTF8 instead.
*
* @param {string} path - An absolute file path.
* @returns {DOMString} The file content.
*/
async readEncoded(path) {
const arr = await IOUtils.read(path);
const str = this.uint8ArrayToByteString(arr);
const charset = this.detectCharset(str);
return new TextDecoder(charset).decode(arr);
},
};