The Tor Browser: addon-sdk/source/lib/sdk/io/text-streams.js@6474c204b198 (annotated)

addon-sdk/source/lib/sdk/io/text-streams.js@6474c204b198 (annotated)

addon-sdk/source/lib/sdk/io/text-streams.js

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* 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
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 "use strict";
 module.metadata = {
   "stability": "experimental"
 };
 const {Cc,Ci,Cu,components} = require("chrome");
 var NetUtil = {};
 Cu.import("resource://gre/modules/NetUtil.jsm", NetUtil);
 NetUtil = NetUtil.NetUtil;
 // NetUtil.asyncCopy() uses this buffer length, and since we call it, for best
 // performance we use it, too.
 const BUFFER_BYTE_LEN = 0x8000;
 const PR_UINT32_MAX = 0xffffffff;
 const DEFAULT_CHARSET = "UTF-8";
 exports.TextReader = TextReader;
 exports.TextWriter = TextWriter;
 /**
  * An input stream that reads text from a backing stream using a given text
  * encoding.
  *
  * @param inputStream
  *        The stream is backed by this nsIInputStream.  It must already be
  *        opened.
  * @param charset
  *        Text in inputStream is expected to be in this character encoding.  If
  *        not given, "UTF-8" is assumed.  See nsICharsetConverterManager.idl for
  *        documentation on how to determine other valid values for this.
  */
 function TextReader(inputStream, charset) {
   const self = this;
   charset = checkCharset(charset);
   let stream = Cc["@mozilla.org/intl/converter-input-stream;1"].
                createInstance(Ci.nsIConverterInputStream);
   stream.init(inputStream, charset, BUFFER_BYTE_LEN,
               Ci.nsIConverterInputStream.DEFAULT_REPLACEMENT_CHARACTER);
   let manager = new StreamManager(this, stream);
   /**
    * Reads a string from the stream.  If the stream is closed, an exception is
    * thrown.
    *
    * @param  numChars
    *         The number of characters to read.  If not given, the remainder of
    *         the stream is read.
    * @return The string read.  If the stream is already at EOS, returns the
    *         empty string.
    */
   this.read = function TextReader_read(numChars) {
     manager.ensureOpened();
     let readAll = false;
     if (typeof(numChars) === "number")
       numChars = Math.max(numChars, 0);
     else
       readAll = true;
     let str = "";
     let totalRead = 0;
     let chunkRead = 1;
     // Read in numChars or until EOS, whichever comes first.  Note that the
     // units here are characters, not bytes.
     while (true) {
       let chunk = {};
       let toRead = readAll ?
                    PR_UINT32_MAX :
                    Math.min(numChars - totalRead, PR_UINT32_MAX);
       if (toRead <= 0 || chunkRead <= 0)
         break;
       // The converter stream reads in at most BUFFER_BYTE_LEN bytes in a call
       // to readString, enough to fill its byte buffer.  chunkRead will be the
       // number of characters encoded by the bytes in that buffer.
       chunkRead = stream.readString(toRead, chunk);
       str += chunk.value;
       totalRead += chunkRead;
     }
     return str;
   };
 }
 /**
  * A buffered output stream that writes text to a backing stream using a given
  * text encoding.
  *
  * @param outputStream
  *        The stream is backed by this nsIOutputStream.  It must already be
  *        opened.
  * @param charset
  *        Text will be written to outputStream using this character encoding.
  *        If not given, "UTF-8" is assumed.  See nsICharsetConverterManager.idl
  *        for documentation on how to determine other valid values for this.
  */
 function TextWriter(outputStream, charset) {
   const self = this;
   charset = checkCharset(charset);
   let stream = outputStream;
   // Buffer outputStream if it's not already.
   let ioUtils = Cc["@mozilla.org/io-util;1"].getService(Ci.nsIIOUtil);
   if (!ioUtils.outputStreamIsBuffered(outputStream)) {
     stream = Cc["@mozilla.org/network/buffered-output-stream;1"].
              createInstance(Ci.nsIBufferedOutputStream);
     stream.init(outputStream, BUFFER_BYTE_LEN);
   }
   // I'd like to use nsIConverterOutputStream.  But NetUtil.asyncCopy(), which
   // we use below in writeAsync(), naturally expects its sink to be an instance
   // of nsIOutputStream, which nsIConverterOutputStream's only implementation is
   // not.  So we use uconv and manually convert all strings before writing to
   // outputStream.
   let uconv = Cc["@mozilla.org/intl/scriptableunicodeconverter"].
               createInstance(Ci.nsIScriptableUnicodeConverter);
   uconv.charset = charset;
   let manager = new StreamManager(this, stream);
   /**
    * Flushes the backing stream's buffer.
    */
   this.flush = function TextWriter_flush() {
     manager.ensureOpened();
     stream.flush();
   };
   /**
    * Writes a string to the stream.  If the stream is closed, an exception is
    * thrown.
    *
    * @param str
    *        The string to write.
    */
   this.write = function TextWriter_write(str) {
     manager.ensureOpened();
     let istream = uconv.convertToInputStream(str);
     let len = istream.available();
     while (len > 0) {
       stream.writeFrom(istream, len);
       len = istream.available();
     }
     istream.close();
   };
   /**
    * Writes a string on a background thread.  After the write completes, the
    * backing stream's buffer is flushed, and both the stream and the backing
    * stream are closed, also on the background thread.  If the stream is already
    * closed, an exception is thrown immediately.
    *
    * @param str
    *        The string to write.
    * @param callback
    *        An optional function.  If given, it's called as callback(error) when
    *        the write completes.  error is an Error object or undefined if there
    *        was no error.  Inside callback, |this| is the stream object.
    */
   this.writeAsync = function TextWriter_writeAsync(str, callback) {
     manager.ensureOpened();
     let istream = uconv.convertToInputStream(str);
     NetUtil.asyncCopy(istream, stream, function (result) {
         let err = components.isSuccessCode(result) ? undefined :
         new Error("An error occured while writing to the stream: " + result);
       if (err)
         console.error(err);
       // asyncCopy() closes its output (and input) stream.
       manager.opened = false;
       if (typeof(callback) === "function") {
         try {
           callback.call(self, err);
         }
         catch (exc) {
           console.exception(exc);
         }
       }
     });
   };
 }
 // This manages the lifetime of stream, a TextReader or TextWriter.  It defines
 // closed and close() on stream and registers an unload listener that closes
 // rawStream if it's still opened.  It also provides ensureOpened(), which
 // throws an exception if the stream is closed.
 function StreamManager(stream, rawStream) {
   const self = this;
   this.rawStream = rawStream;
   this.opened = true;
   /**
    * True iff the stream is closed.
    */
   stream.__defineGetter__("closed", function stream_closed() {
     return !self.opened;
   });
   /**
    * Closes both the stream and its backing stream.  If the stream is already
    * closed, an exception is thrown.  For TextWriters, this first flushes the
    * backing stream's buffer.
    */
   stream.close = function stream_close() {
     self.ensureOpened();
     self.unload();
   };
   require("../system/unload").ensure(this);
 }
 StreamManager.prototype = {
   ensureOpened: function StreamManager_ensureOpened() {
     if (!this.opened)
       throw new Error("The stream is closed and cannot be used.");
   },
   unload: function StreamManager_unload() {
     // TextWriter.writeAsync() causes rawStream to close and therefore sets
     // opened to false, so check that we're still opened.
     if (this.opened) {
       // Calling close() on both an nsIUnicharInputStream and
       // nsIBufferedOutputStream closes their backing streams.  It also forces
       // nsIOutputStreams to flush first.
       this.rawStream.close();
       this.opened = false;
     }
   }
 };
 function checkCharset(charset) {
   return typeof(charset) === "string" ? charset : DEFAULT_CHARSET;
 }