diff options
Diffstat (limited to 'middleware/node_modules/iconv-lite/encodings/internal.js')
-rw-r--r-- | middleware/node_modules/iconv-lite/encodings/internal.js | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/middleware/node_modules/iconv-lite/encodings/internal.js b/middleware/node_modules/iconv-lite/encodings/internal.js new file mode 100644 index 0000000..05ce38b --- /dev/null +++ b/middleware/node_modules/iconv-lite/encodings/internal.js @@ -0,0 +1,188 @@ +"use strict"; +var Buffer = require("safer-buffer").Buffer; + +// Export Node.js internal encodings. + +module.exports = { + // Encodings + utf8: { type: "_internal", bomAware: true}, + cesu8: { type: "_internal", bomAware: true}, + unicode11utf8: "utf8", + + ucs2: { type: "_internal", bomAware: true}, + utf16le: "ucs2", + + binary: { type: "_internal" }, + base64: { type: "_internal" }, + hex: { type: "_internal" }, + + // Codec. + _internal: InternalCodec, +}; + +//------------------------------------------------------------------------------ + +function InternalCodec(codecOptions, iconv) { + this.enc = codecOptions.encodingName; + this.bomAware = codecOptions.bomAware; + + if (this.enc === "base64") + this.encoder = InternalEncoderBase64; + else if (this.enc === "cesu8") { + this.enc = "utf8"; // Use utf8 for decoding. + this.encoder = InternalEncoderCesu8; + + // Add decoder for versions of Node not supporting CESU-8 + if (Buffer.from('eda0bdedb2a9', 'hex').toString() !== '💩') { + this.decoder = InternalDecoderCesu8; + this.defaultCharUnicode = iconv.defaultCharUnicode; + } + } +} + +InternalCodec.prototype.encoder = InternalEncoder; +InternalCodec.prototype.decoder = InternalDecoder; + +//------------------------------------------------------------------------------ + +// We use node.js internal decoder. Its signature is the same as ours. +var StringDecoder = require('string_decoder').StringDecoder; + +if (!StringDecoder.prototype.end) // Node v0.8 doesn't have this method. + StringDecoder.prototype.end = function() {}; + + +function InternalDecoder(options, codec) { + StringDecoder.call(this, codec.enc); +} + +InternalDecoder.prototype = StringDecoder.prototype; + + +//------------------------------------------------------------------------------ +// Encoder is mostly trivial + +function InternalEncoder(options, codec) { + this.enc = codec.enc; +} + +InternalEncoder.prototype.write = function(str) { + return Buffer.from(str, this.enc); +} + +InternalEncoder.prototype.end = function() { +} + + +//------------------------------------------------------------------------------ +// Except base64 encoder, which must keep its state. + +function InternalEncoderBase64(options, codec) { + this.prevStr = ''; +} + +InternalEncoderBase64.prototype.write = function(str) { + str = this.prevStr + str; + var completeQuads = str.length - (str.length % 4); + this.prevStr = str.slice(completeQuads); + str = str.slice(0, completeQuads); + + return Buffer.from(str, "base64"); +} + +InternalEncoderBase64.prototype.end = function() { + return Buffer.from(this.prevStr, "base64"); +} + + +//------------------------------------------------------------------------------ +// CESU-8 encoder is also special. + +function InternalEncoderCesu8(options, codec) { +} + +InternalEncoderCesu8.prototype.write = function(str) { + var buf = Buffer.alloc(str.length * 3), bufIdx = 0; + for (var i = 0; i < str.length; i++) { + var charCode = str.charCodeAt(i); + // Naive implementation, but it works because CESU-8 is especially easy + // to convert from UTF-16 (which all JS strings are encoded in). + if (charCode < 0x80) + buf[bufIdx++] = charCode; + else if (charCode < 0x800) { + buf[bufIdx++] = 0xC0 + (charCode >>> 6); + buf[bufIdx++] = 0x80 + (charCode & 0x3f); + } + else { // charCode will always be < 0x10000 in javascript. + buf[bufIdx++] = 0xE0 + (charCode >>> 12); + buf[bufIdx++] = 0x80 + ((charCode >>> 6) & 0x3f); + buf[bufIdx++] = 0x80 + (charCode & 0x3f); + } + } + return buf.slice(0, bufIdx); +} + +InternalEncoderCesu8.prototype.end = function() { +} + +//------------------------------------------------------------------------------ +// CESU-8 decoder is not implemented in Node v4.0+ + +function InternalDecoderCesu8(options, codec) { + this.acc = 0; + this.contBytes = 0; + this.accBytes = 0; + this.defaultCharUnicode = codec.defaultCharUnicode; +} + +InternalDecoderCesu8.prototype.write = function(buf) { + var acc = this.acc, contBytes = this.contBytes, accBytes = this.accBytes, + res = ''; + for (var i = 0; i < buf.length; i++) { + var curByte = buf[i]; + if ((curByte & 0xC0) !== 0x80) { // Leading byte + if (contBytes > 0) { // Previous code is invalid + res += this.defaultCharUnicode; + contBytes = 0; + } + + if (curByte < 0x80) { // Single-byte code + res += String.fromCharCode(curByte); + } else if (curByte < 0xE0) { // Two-byte code + acc = curByte & 0x1F; + contBytes = 1; accBytes = 1; + } else if (curByte < 0xF0) { // Three-byte code + acc = curByte & 0x0F; + contBytes = 2; accBytes = 1; + } else { // Four or more are not supported for CESU-8. + res += this.defaultCharUnicode; + } + } else { // Continuation byte + if (contBytes > 0) { // We're waiting for it. + acc = (acc << 6) | (curByte & 0x3f); + contBytes--; accBytes++; + if (contBytes === 0) { + // Check for overlong encoding, but support Modified UTF-8 (encoding NULL as C0 80) + if (accBytes === 2 && acc < 0x80 && acc > 0) + res += this.defaultCharUnicode; + else if (accBytes === 3 && acc < 0x800) + res += this.defaultCharUnicode; + else + // Actually add character. + res += String.fromCharCode(acc); + } + } else { // Unexpected continuation byte + res += this.defaultCharUnicode; + } + } + } + this.acc = acc; this.contBytes = contBytes; this.accBytes = accBytes; + return res; +} + +InternalDecoderCesu8.prototype.end = function() { + var res = 0; + if (this.contBytes > 0) + res += this.defaultCharUnicode; + return res; +} |