netwerk/base/public/nsIInputStreamPump.idl

   1 /* ***** BEGIN LICENSE BLOCK *****
   2  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   3  *
   4  * The contents of this file are subject to the Mozilla Public License Version
   5  * 1.1 (the "License"); you may not use this file except in compliance with
   6  * the License. You may obtain a copy of the License at
   7  * http://www.mozilla.org/MPL/
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   9  * Software distributed under the License is distributed on an "AS IS" basis,
  10  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  11  * for the specific language governing rights and limitations under the
  12  * License.
  13  *
  14  * The Original Code is Mozilla.
  15  *
  16  * The Initial Developer of the Original Code is
  17  * Netscape Communications Corporation.
  18  * Portions created by the Initial Developer are Copyright (C) 2002
  19  * the Initial Developer. All Rights Reserved.
  20  *
  21  * Contributor(s):
  22  *   Darin Fisher <darin@netscape.com>
  23  *   Christian Biesinger <cbiesinger@web.de>
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either the GNU General Public License Version 2 or later (the "GPL"), or
  27  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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  35  * the terms of any one of the MPL, the GPL or the LGPL.
  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 #include "nsIRequest.idl"
  40
  41 interface nsIInputStream;
  42 interface nsIStreamListener;
  43
  44 /**
  45  * nsIInputStreamPump
  46  *
  47  * This interface provides a means to configure and use a input stream pump
  48  * instance.  The input stream pump will asynchronously read from a input
  49  * stream, and push data to a nsIStreamListener instance.  It utilizes the
  50  * current thread's nsIEventTarget in order to make reading from the stream
  51  * asynchronous.
  52  *
  53  * If the given stream supports nsIAsyncInputStream, then the stream pump will
  54  * call the stream's AsyncWait method to drive the stream listener.  Otherwise,
  55  * the stream will be read on a background thread utilizing the stream
  56  * transport service.  More details are provided below.
  57  */
  58 [scriptable, uuid(400F5468-97E7-4d2b-9C65-A82AECC7AE82)]
  59 interface nsIInputStreamPump : nsIRequest
  60 {
  61     /**
  62      * Initialize the input stream pump.
  63      *
  64      * @param aStream
  65      *        contains the data to be read.  if the input stream is non-blocking,
  66      *        then it will be QI'd to nsIAsyncInputStream.  if the QI succeeds
  67      *        then the stream will be read directly.  otherwise, it will be read
  68      *        on a background thread using the stream transport service.
  69      * @param aStreamPos
  70      *        specifies the stream offset from which to start reading.  the
  71      *        offset value is absolute.  pass -1 to specify the current offset.
  72      *        NOTE: this parameter is ignored if the underlying stream does not
  73      *        implement nsISeekableStream.
  74      * @param aStreamLen
  75      *        specifies how much data to read from the stream.  pass -1 to read
  76      *        all data available in the stream.
  77      * @param aSegmentSize
  78      *        if the stream transport service is used, then this parameter
  79      *        specifies the segment size for the stream transport's buffer.
  80      *        pass 0 to specify the default value.
  81      * @param aSegmentCount
  82      *        if the stream transport service is used, then this parameter
  83      *        specifies the segment count for the stream transport's buffer.
  84      *        pass 0 to specify the default value.
  85      * @param aCloseWhenDone
  86      *        if true, the input stream will be closed after it has been read.
  87      */
  88     void init(in nsIInputStream aStream,
  89               in long long      aStreamPos,
  90               in long long      aStreamLen,
  91               in unsigned long  aSegmentSize,
  92               in unsigned long  aSegmentCount,
  93               in boolean        aCloseWhenDone);
  94
  95     /**
  96      * asyncRead causes the input stream to be read in chunks and delivered
  97      * asynchronously to the listener via OnDataAvailable.
  98      *
  99      * @param aListener
 100      *        receives notifications.
 101      * @param aListenerContext
 102      *        passed to listener methods.
 103      */
 104     void asyncRead(in nsIStreamListener aListener,
 105                    in nsISupports       aListenerContext);
 106 };