necouchman commented on a change in pull request #697: URL: https://github.com/apache/guacamole-client/pull/697#discussion_r805197344
########## File path: guacamole-common-js/src/main/webapp/modules/UTF8Parser.js ########## @@ -0,0 +1,126 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +var Guacamole = Guacamole || {}; + +/** + * Parser that decodes UTF-8 text from a series of provided ArrayBuffers. + * Multi-byte characters that continue from one buffer to the next are handled + * correctly. + * + * @constructor + */ +Guacamole.UTF8Parser = function UTF8Parser() { + + /** + * The number of bytes remaining for the current codepoint. + * + * @private + * @type {!number} + */ + var bytesRemaining = 0; + + /** + * The current codepoint value, as calculated from bytes read so far. + * + * @private + * @type {!number} + */ + var codepoint = 0; + + /** + * Decodes the given UTF-8 data into a Unicode string, returning a string + * containing all complete UTF-8 characters within the provided data. The + * data may end in the middle of a multi-byte character, in which case the + * complete character will be returned from a later call to decode() after + * enough bytes have been provided. + * + * @private + * @param {!ArrayBuffer} buffer + * Arbitrary UTF-8 data. + * + * @return {!string} + * The decoded Unicode string. + */ + this.decode = function decode(buffer) { + + var text = ''; + + var bytes = new Uint8Array(buffer); + for (var i=0; i<bytes.length; i++) { + + // Get current byte + var value = bytes[i]; + + // Start new codepoint if nothing yet read + if (bytesRemaining === 0) { + + // 1 byte (0xxxxxxx) + if ((value | 0x7F) === 0x7F) + text += String.fromCharCode(value); + + // 2 byte (110xxxxx) + else if ((value | 0x1F) === 0xDF) { + codepoint = value & 0x1F; + bytesRemaining = 1; + } + + // 3 byte (1110xxxx) + else if ((value | 0x0F )=== 0xEF) { + codepoint = value & 0x0F; + bytesRemaining = 2; + } + + // 4 byte (11110xxx) + else if ((value | 0x07) === 0xF7) { + codepoint = value & 0x07; + bytesRemaining = 3; + } + + // Invalid byte + else + text += '\uFFFD'; Review comment: I'm sure it's just my overall ignorance of Unicode, but does this value have some special meaning, or is there some reason why, when a byte is invalid, you'd write this value? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
