src/third_party/devtools/node_modules/iconv-lite/encodings/utf7.js - cobalt - Git at Google

 "use strict";
 var Buffer = require("safer-buffer").Buffer;

 // UTF-7 codec, according to https://tools.ietf.org/html/rfc2152
 // See also below a UTF-7-IMAP codec, according to http://tools.ietf.org/html/rfc3501#section-5.1.3

 exports.utf7 = Utf7Codec;
 exports.unicode11utf7 = 'utf7'; // Alias UNICODE-1-1-UTF-7
 function Utf7Codec(codecOptions, iconv) {
     this.iconv = iconv;
 };

 Utf7Codec.prototype.encoder = Utf7Encoder;
 Utf7Codec.prototype.decoder = Utf7Decoder;
 Utf7Codec.prototype.bomAware = true;


 // -- Encoding

 var nonDirectChars = /[^A-Za-z0-9'\(\),-\.\/:\? \n\r\t]+/g;

 function Utf7Encoder(options, codec) {
     this.iconv = codec.iconv;
 }

 Utf7Encoder.prototype.write = function(str) {
     // Naive implementation.
     // Non-direct chars are encoded as "+<base64>-"; single "+" char is encoded as "+-".
     return Buffer.from(str.replace(nonDirectChars, function(chunk) {
         return "+" + (chunk === '+' ? '' :
             this.iconv.encode(chunk, 'utf16-be').toString('base64').replace(/=+$/, ''))
             + "-";
     }.bind(this)));
 }

 Utf7Encoder.prototype.end = function() {
 }


 // -- Decoding

 function Utf7Decoder(options, codec) {
     this.iconv = codec.iconv;
     this.inBase64 = false;
     this.base64Accum = '';
 }

 var base64Regex = /[A-Za-z0-9\/+]/;
 var base64Chars = [];
 for (var i = 0; i < 256; i++)
     base64Chars[i] = base64Regex.test(String.fromCharCode(i));

 var plusChar = '+'.charCodeAt(0),
     minusChar = '-'.charCodeAt(0),
     andChar = '&'.charCodeAt(0);

 Utf7Decoder.prototype.write = function(buf) {
     var res = "", lastI = 0,
         inBase64 = this.inBase64,
         base64Accum = this.base64Accum;

     // The decoder is more involved as we must handle chunks in stream.

     for (var i = 0; i < buf.length; i++) {
         if (!inBase64) { // We're in direct mode.
             // Write direct chars until '+'
             if (buf[i] == plusChar) {
                 res += this.iconv.decode(buf.slice(lastI, i), "ascii"); // Write direct chars.
                 lastI = i+1;
                 inBase64 = true;
             }
         } else { // We decode base64.
             if (!base64Chars[buf[i]]) { // Base64 ended.
                 if (i == lastI && buf[i] == minusChar) {// "+-" -> "+"
                     res += "+";
                 } else {
                     var b64str = base64Accum + buf.slice(lastI, i).toString();
                     res += this.iconv.decode(Buffer.from(b64str, 'base64'), "utf16-be");
                 }

                 if (buf[i] != minusChar) // Minus is absorbed after base64.
                     i--;

                 lastI = i+1;
                 inBase64 = false;
                 base64Accum = '';
             }
         }
     }

     if (!inBase64) {
         res += this.iconv.decode(buf.slice(lastI), "ascii"); // Write direct chars.
     } else {
         var b64str = base64Accum + buf.slice(lastI).toString();

         var canBeDecoded = b64str.length - (b64str.length % 8); // Minimal chunk: 2 quads -> 2x3 bytes -> 3 chars.
         base64Accum = b64str.slice(canBeDecoded); // The rest will be decoded in future.
         b64str = b64str.slice(0, canBeDecoded);

         res += this.iconv.decode(Buffer.from(b64str, 'base64'), "utf16-be");
     }

     this.inBase64 = inBase64;
     this.base64Accum = base64Accum;

     return res;
 }

 Utf7Decoder.prototype.end = function() {
     var res = "";
     if (this.inBase64 && this.base64Accum.length > 0)
         res = this.iconv.decode(Buffer.from(this.base64Accum, 'base64'), "utf16-be");

     this.inBase64 = false;
     this.base64Accum = '';
     return res;
 }


 // UTF-7-IMAP codec.
 // RFC3501 Sec. 5.1.3 Modified UTF-7 (http://tools.ietf.org/html/rfc3501#section-5.1.3)
 // Differences:
 //  * Base64 part is started by "&" instead of "+"
 //  * Direct characters are 0x20-0x7E, except "&" (0x26)
 //  * In Base64, "," is used instead of "/"
 //  * Base64 must not be used to represent direct characters.
 //  * No implicit shift back from Base64 (should always end with '-')
 //  * String must end in non-shifted position.
 //  * "-&" while in base64 is not allowed.


 exports.utf7imap = Utf7IMAPCodec;
 function Utf7IMAPCodec(codecOptions, iconv) {
     this.iconv = iconv;
 };

 Utf7IMAPCodec.prototype.encoder = Utf7IMAPEncoder;
 Utf7IMAPCodec.prototype.decoder = Utf7IMAPDecoder;
 Utf7IMAPCodec.prototype.bomAware = true;


 // -- Encoding

 function Utf7IMAPEncoder(options, codec) {
     this.iconv = codec.iconv;
     this.inBase64 = false;
     this.base64Accum = Buffer.alloc(6);
     this.base64AccumIdx = 0;
 }

 Utf7IMAPEncoder.prototype.write = function(str) {
     var inBase64 = this.inBase64,
         base64Accum = this.base64Accum,
         base64AccumIdx = this.base64AccumIdx,
         buf = Buffer.alloc(str.length*5 + 10), bufIdx = 0;

     for (var i = 0; i < str.length; i++) {
         var uChar = str.charCodeAt(i);
         if (0x20 <= uChar && uChar <= 0x7E) { // Direct character or '&'.
             if (inBase64) {
                 if (base64AccumIdx > 0) {
                     bufIdx += buf.write(base64Accum.slice(0, base64AccumIdx).toString('base64').replace(/\//g, ',').replace(/=+$/, ''), bufIdx);
                     base64AccumIdx = 0;
                 }

                 buf[bufIdx++] = minusChar; // Write '-', then go to direct mode.
                 inBase64 = false;
             }

             if (!inBase64) {
                 buf[bufIdx++] = uChar; // Write direct character

                 if (uChar === andChar)  // Ampersand -> '&-'
                     buf[bufIdx++] = minusChar;
             }

         } else { // Non-direct character
             if (!inBase64) {
                 buf[bufIdx++] = andChar; // Write '&', then go to base64 mode.
                 inBase64 = true;
             }
             if (inBase64) {
                 base64Accum[base64AccumIdx++] = uChar >> 8;
                 base64Accum[base64AccumIdx++] = uChar & 0xFF;

                 if (base64AccumIdx == base64Accum.length) {
                     bufIdx += buf.write(base64Accum.toString('base64').replace(/\//g, ','), bufIdx);
                     base64AccumIdx = 0;
                 }
             }
         }
     }

     this.inBase64 = inBase64;
     this.base64AccumIdx = base64AccumIdx;

     return buf.slice(0, bufIdx);
 }

 Utf7IMAPEncoder.prototype.end = function() {
     var buf = Buffer.alloc(10), bufIdx = 0;
     if (this.inBase64) {
         if (this.base64AccumIdx > 0) {
             bufIdx += buf.write(this.base64Accum.slice(0, this.base64AccumIdx).toString('base64').replace(/\//g, ',').replace(/=+$/, ''), bufIdx);
             this.base64AccumIdx = 0;
         }

         buf[bufIdx++] = minusChar; // Write '-', then go to direct mode.
         this.inBase64 = false;
     }

     return buf.slice(0, bufIdx);
 }


 // -- Decoding

 function Utf7IMAPDecoder(options, codec) {
     this.iconv = codec.iconv;
     this.inBase64 = false;
     this.base64Accum = '';
 }

 var base64IMAPChars = base64Chars.slice();
 base64IMAPChars[','.charCodeAt(0)] = true;

 Utf7IMAPDecoder.prototype.write = function(buf) {
     var res = "", lastI = 0,
         inBase64 = this.inBase64,
         base64Accum = this.base64Accum;

     // The decoder is more involved as we must handle chunks in stream.
     // It is forgiving, closer to standard UTF-7 (for example, '-' is optional at the end).

     for (var i = 0; i < buf.length; i++) {
         if (!inBase64) { // We're in direct mode.
             // Write direct chars until '&'
             if (buf[i] == andChar) {
                 res += this.iconv.decode(buf.slice(lastI, i), "ascii"); // Write direct chars.
                 lastI = i+1;
                 inBase64 = true;
             }
         } else { // We decode base64.
             if (!base64IMAPChars[buf[i]]) { // Base64 ended.
                 if (i == lastI && buf[i] == minusChar) { // "&-" -> "&"
                     res += "&";
                 } else {
                     var b64str = base64Accum + buf.slice(lastI, i).toString().replace(/,/g, '/');
                     res += this.iconv.decode(Buffer.from(b64str, 'base64'), "utf16-be");
                 }

                 if (buf[i] != minusChar) // Minus may be absorbed after base64.
                     i--;

                 lastI = i+1;
                 inBase64 = false;
                 base64Accum = '';
             }
         }
     }

     if (!inBase64) {
         res += this.iconv.decode(buf.slice(lastI), "ascii"); // Write direct chars.
     } else {
         var b64str = base64Accum + buf.slice(lastI).toString().replace(/,/g, '/');

         var canBeDecoded = b64str.length - (b64str.length % 8); // Minimal chunk: 2 quads -> 2x3 bytes -> 3 chars.
         base64Accum = b64str.slice(canBeDecoded); // The rest will be decoded in future.
         b64str = b64str.slice(0, canBeDecoded);

         res += this.iconv.decode(Buffer.from(b64str, 'base64'), "utf16-be");
     }

     this.inBase64 = inBase64;
     this.base64Accum = base64Accum;

     return res;
 }

 Utf7IMAPDecoder.prototype.end = function() {
     var res = "";
     if (this.inBase64 && this.base64Accum.length > 0)
         res = this.iconv.decode(Buffer.from(this.base64Accum, 'base64'), "utf16-be");

     this.inBase64 = false;
     this.base64Accum = '';
     return res;
 }
	"use strict";
	var Buffer = require("safer-buffer").Buffer;

	// UTF-7 codec, according to https://tools.ietf.org/html/rfc2152
	// See also below a UTF-7-IMAP codec, according to http://tools.ietf.org/html/rfc3501#section-5.1.3

	exports.utf7 = Utf7Codec;
	exports.unicode11utf7 = 'utf7'; // Alias UNICODE-1-1-UTF-7
	function Utf7Codec(codecOptions, iconv) {
	this.iconv = iconv;
	};

	Utf7Codec.prototype.encoder = Utf7Encoder;
	Utf7Codec.prototype.decoder = Utf7Decoder;
	Utf7Codec.prototype.bomAware = true;


	// -- Encoding

	var nonDirectChars = /[^A-Za-z0-9'\(\),-\.\/:\? \n\r\t]+/g;

	function Utf7Encoder(options, codec) {
	this.iconv = codec.iconv;
	}

	Utf7Encoder.prototype.write = function(str) {
	// Naive implementation.
	// Non-direct chars are encoded as "+<base64>-"; single "+" char is encoded as "+-".
	return Buffer.from(str.replace(nonDirectChars, function(chunk) {
	return "+" + (chunk === '+' ? '' :
	this.iconv.encode(chunk, 'utf16-be').toString('base64').replace(/=+$/, ''))
	+ "-";
	}.bind(this)));
	}

	Utf7Encoder.prototype.end = function() {
	}


	// -- Decoding

	function Utf7Decoder(options, codec) {
	this.iconv = codec.iconv;
	this.inBase64 = false;
	this.base64Accum = '';
	}

	var base64Regex = /[A-Za-z0-9\/+]/;
	var base64Chars = [];
	for (var i = 0; i < 256; i++)
	base64Chars[i] = base64Regex.test(String.fromCharCode(i));

	var plusChar = '+'.charCodeAt(0),
	minusChar = '-'.charCodeAt(0),
	andChar = '&'.charCodeAt(0);

	Utf7Decoder.prototype.write = function(buf) {
	var res = "", lastI = 0,
	inBase64 = this.inBase64,
	base64Accum = this.base64Accum;

	// The decoder is more involved as we must handle chunks in stream.

	for (var i = 0; i < buf.length; i++) {
	if (!inBase64) { // We're in direct mode.
	// Write direct chars until '+'
	if (buf[i] == plusChar) {
	res += this.iconv.decode(buf.slice(lastI, i), "ascii"); // Write direct chars.
	lastI = i+1;
	inBase64 = true;
	}
	} else { // We decode base64.
	if (!base64Chars[buf[i]]) { // Base64 ended.
	if (i == lastI && buf[i] == minusChar) {// "+-" -> "+"
	res += "+";
	} else {
	var b64str = base64Accum + buf.slice(lastI, i).toString();
	res += this.iconv.decode(Buffer.from(b64str, 'base64'), "utf16-be");
	}

	if (buf[i] != minusChar) // Minus is absorbed after base64.
	i--;

	lastI = i+1;
	inBase64 = false;
	base64Accum = '';
	}
	}
	}

	if (!inBase64) {
	res += this.iconv.decode(buf.slice(lastI), "ascii"); // Write direct chars.
	} else {
	var b64str = base64Accum + buf.slice(lastI).toString();

	var canBeDecoded = b64str.length - (b64str.length % 8); // Minimal chunk: 2 quads -> 2x3 bytes -> 3 chars.
	base64Accum = b64str.slice(canBeDecoded); // The rest will be decoded in future.
	b64str = b64str.slice(0, canBeDecoded);

	res += this.iconv.decode(Buffer.from(b64str, 'base64'), "utf16-be");
	}

	this.inBase64 = inBase64;
	this.base64Accum = base64Accum;

	return res;
	}

	Utf7Decoder.prototype.end = function() {
	var res = "";
	if (this.inBase64 && this.base64Accum.length > 0)
	res = this.iconv.decode(Buffer.from(this.base64Accum, 'base64'), "utf16-be");

	this.inBase64 = false;
	this.base64Accum = '';
	return res;
	}


	// UTF-7-IMAP codec.
	// RFC3501 Sec. 5.1.3 Modified UTF-7 (http://tools.ietf.org/html/rfc3501#section-5.1.3)
	// Differences:
	// * Base64 part is started by "&" instead of "+"
	// * Direct characters are 0x20-0x7E, except "&" (0x26)
	// * In Base64, "," is used instead of "/"
	// * Base64 must not be used to represent direct characters.
	// * No implicit shift back from Base64 (should always end with '-')
	// * String must end in non-shifted position.
	// * "-&" while in base64 is not allowed.


	exports.utf7imap = Utf7IMAPCodec;
	function Utf7IMAPCodec(codecOptions, iconv) {
	this.iconv = iconv;
	};

	Utf7IMAPCodec.prototype.encoder = Utf7IMAPEncoder;
	Utf7IMAPCodec.prototype.decoder = Utf7IMAPDecoder;
	Utf7IMAPCodec.prototype.bomAware = true;


	// -- Encoding

	function Utf7IMAPEncoder(options, codec) {
	this.iconv = codec.iconv;
	this.inBase64 = false;
	this.base64Accum = Buffer.alloc(6);
	this.base64AccumIdx = 0;
	}

	Utf7IMAPEncoder.prototype.write = function(str) {
	var inBase64 = this.inBase64,
	base64Accum = this.base64Accum,
	base64AccumIdx = this.base64AccumIdx,
	buf = Buffer.alloc(str.length*5 + 10), bufIdx = 0;

	for (var i = 0; i < str.length; i++) {
	var uChar = str.charCodeAt(i);
	if (0x20 <= uChar && uChar <= 0x7E) { // Direct character or '&'.
	if (inBase64) {
	if (base64AccumIdx > 0) {
	bufIdx += buf.write(base64Accum.slice(0, base64AccumIdx).toString('base64').replace(/\//g, ',').replace(/=+$/, ''), bufIdx);
	base64AccumIdx = 0;
	}

	buf[bufIdx++] = minusChar; // Write '-', then go to direct mode.
	inBase64 = false;
	}

	if (!inBase64) {
	buf[bufIdx++] = uChar; // Write direct character

	if (uChar === andChar) // Ampersand -> '&-'
	buf[bufIdx++] = minusChar;
	}

	} else { // Non-direct character
	if (!inBase64) {
	buf[bufIdx++] = andChar; // Write '&', then go to base64 mode.
	inBase64 = true;
	}
	if (inBase64) {
	base64Accum[base64AccumIdx++] = uChar >> 8;
	base64Accum[base64AccumIdx++] = uChar & 0xFF;

	if (base64AccumIdx == base64Accum.length) {
	bufIdx += buf.write(base64Accum.toString('base64').replace(/\//g, ','), bufIdx);
	base64AccumIdx = 0;
	}
	}
	}
	}

	this.inBase64 = inBase64;
	this.base64AccumIdx = base64AccumIdx;

	return buf.slice(0, bufIdx);
	}

	Utf7IMAPEncoder.prototype.end = function() {
	var buf = Buffer.alloc(10), bufIdx = 0;
	if (this.inBase64) {
	if (this.base64AccumIdx > 0) {
	bufIdx += buf.write(this.base64Accum.slice(0, this.base64AccumIdx).toString('base64').replace(/\//g, ',').replace(/=+$/, ''), bufIdx);
	this.base64AccumIdx = 0;
	}

	buf[bufIdx++] = minusChar; // Write '-', then go to direct mode.
	this.inBase64 = false;
	}

	return buf.slice(0, bufIdx);
	}


	// -- Decoding

	function Utf7IMAPDecoder(options, codec) {
	this.iconv = codec.iconv;
	this.inBase64 = false;
	this.base64Accum = '';
	}

	var base64IMAPChars = base64Chars.slice();
	base64IMAPChars[','.charCodeAt(0)] = true;

	Utf7IMAPDecoder.prototype.write = function(buf) {
	var res = "", lastI = 0,
	inBase64 = this.inBase64,
	base64Accum = this.base64Accum;

	// The decoder is more involved as we must handle chunks in stream.
	// It is forgiving, closer to standard UTF-7 (for example, '-' is optional at the end).

	for (var i = 0; i < buf.length; i++) {
	if (!inBase64) { // We're in direct mode.
	// Write direct chars until '&'
	if (buf[i] == andChar) {
	res += this.iconv.decode(buf.slice(lastI, i), "ascii"); // Write direct chars.
	lastI = i+1;
	inBase64 = true;
	}
	} else { // We decode base64.
	if (!base64IMAPChars[buf[i]]) { // Base64 ended.
	if (i == lastI && buf[i] == minusChar) { // "&-" -> "&"
	res += "&";
	} else {
	var b64str = base64Accum + buf.slice(lastI, i).toString().replace(/,/g, '/');
	res += this.iconv.decode(Buffer.from(b64str, 'base64'), "utf16-be");
	}

	if (buf[i] != minusChar) // Minus may be absorbed after base64.
	i--;

	lastI = i+1;
	inBase64 = false;
	base64Accum = '';
	}
	}
	}

	if (!inBase64) {
	res += this.iconv.decode(buf.slice(lastI), "ascii"); // Write direct chars.
	} else {
	var b64str = base64Accum + buf.slice(lastI).toString().replace(/,/g, '/');

	var canBeDecoded = b64str.length - (b64str.length % 8); // Minimal chunk: 2 quads -> 2x3 bytes -> 3 chars.
	base64Accum = b64str.slice(canBeDecoded); // The rest will be decoded in future.
	b64str = b64str.slice(0, canBeDecoded);

	res += this.iconv.decode(Buffer.from(b64str, 'base64'), "utf16-be");
	}

	this.inBase64 = inBase64;
	this.base64Accum = base64Accum;

	return res;
	}

	Utf7IMAPDecoder.prototype.end = function() {
	var res = "";
	if (this.inBase64 && this.base64Accum.length > 0)
	res = this.iconv.decode(Buffer.from(this.base64Accum, 'base64'), "utf16-be");

	this.inBase64 = false;
	this.base64Accum = '';
	return res;
	}