docs/html/class-gioinputstream.html

   1 <html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>gio.InputStream</title><link rel="stylesheet" type="text/css" href="style.css"><meta name="generator" content="DocBook XSL Stylesheets V1.76.1"><link rel="home" href="index.html" title="PyGObject Reference Manual"><link rel="up" href="gio-class-reference.html" title="PyGio Class Reference"><link rel="prev" href="class-gioicon.html" title="gio.Icon"><link rel="next" href="class-gioloadableicon.html" title="gio.LoadableIcon"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">gio.InputStream</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="class-gioicon.html">Prev</a> </td><th width="60%" align="center">PyGio Class Reference</th><td width="20%" align="right"> <a accesskey="n" href="class-gioloadableicon.html">Next</a></td></tr></table><hr></div><div class="refentry" title="gio.InputStream"><a name="class-gioinputstream"></a><div class="titlepage"></div><div class="refnamediv"><h2>gio.InputStream</h2><p>gio.InputStream — Base class for implementing streaming input</p></div><div class="refsect1" title="Synopsis"><a name="id515261"></a><h2>Synopsis</h2><table bgcolor="#D0E0F0" width="100%"><tr><td><pre class="classsynopsis">class <span class="ooclass"><span class="classname">gio.InputStream</span></span>(<span class="ooclass"><span class="classname"><a class="link" href="class-gobject.html" title="gobject.GObject">gobject.GObject</a></span></span>):
   2 <code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--clear-pending" title="gio.InputStream.clear_pending">clear_pending</a></span>(<span class="methodparam"></span>)</code><br><code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--close" title="gio.InputStream.close">close</a></span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>)</code><br><code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--close-async" title="gio.InputStream.close_async">close_async</a></span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>callback</code></strong></span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>io_priority</code></strong></span><span class="initializer">=glib.PRIORITY_DEFAULT</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>user_data</code></strong></span><span class="initializer">=None</span></span>)</code><br><code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--close-finish" title="gio.InputStream.close_finish">close_finish</a></span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>result</code></strong></span></span>)</code><br><code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--has-pending" title="gio.InputStream.has_pending">has_pending</a></span>(<span class="methodparam"></span>)</code><br><code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--is-closed" title="gio.InputStream.is_closed">is_closed</a></span>(<span class="methodparam"></span>)</code><br><code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--read" title="gio.InputStream.read">read</a></span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>count</code></strong></span><span class="initializer">=-1</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>)</code><br><code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--read-async" title="gio.InputStream.read_async">read_async</a></span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>count</code></strong></span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>callback</code></strong></span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>io_priority</code></strong></span><span class="initializer">=glib.PRIORITY_DEFAULT</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>user_data</code></strong></span><span class="initializer">=None</span></span>)</code><br><code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--read-finish" title="gio.InputStream.read_finish">read_finish</a></span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>result</code></strong></span></span>)</code><br><code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--read-part" title="gio.InputStream.read_part">read_part</a></span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>count</code></strong></span><span class="initializer">=-1</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>)</code><br><code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--set-pending" title="gio.InputStream.set_pending">set_pending</a></span>(<span class="methodparam"></span>)</code><br><code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--skip" title="gio.InputStream.skip">skip</a></span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>count</code></strong></span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>)</code><br><code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--skip-async" title="gio.InputStream.skip_async">skip_async</a></span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>count</code></strong></span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>callback</code></strong></span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>io_priority</code></strong></span><span class="initializer">=glib.PRIORITY_DEFAULT</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>user_data</code></strong></span><span class="initializer">=None</span></span>)</code><br><code class="methodsynopsis">    def <span class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--skip-finish" title="gio.InputStream.skip_finish">skip_finish</a></span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>result</code></strong></span></span>)</code><br></pre></td></tr></table></div><div class="refsect1" title="Ancestry"><a name="id515798"></a><h2>Ancestry</h2><pre class="synopsis">+-- <a class="link" href="class-gobject.html" title="gobject.GObject">gobject.GObject</a>
   3   +-- <a class="link" href="class-gioinputstream.html" title="gio.InputStream">gio.InputStream</a>
   4 </pre></div><div class="refsect1" title="Description"><a name="id515820"></a><h2>Description</h2><p>
   5             <a class="link" href="class-gioinputstream.html" title="gio.InputStream"><code class="classname">gio.InputStream</code></a>
   6             has functions to read from a stream (
   7             <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--read" title="gio.InputStream.read">gio.InputStream.read</a></code>()
   8             ), to close a stream (
   9             <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--close" title="gio.InputStream.close">gio.InputStream.close</a></code>()
  10             ) and to skip some content (
  11             <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--skip" title="gio.InputStream.skip">gio.InputStream.skip</a></code>()
  12             ).
  13         </p><p>
  14             To copy the content of an input stream to an output stream without manually
  15             handling the reads and writes, use
  16             <code class="methodname"><PYGTKDOCLINK HREF="method-giooutputstream--skip">gio.OutputStream.splice</PYGTKDOCLINK></code>().
  17         </p><p>
  18             All of these functions have async variants too.
  19         </p></div><div class="refsect1" title="Methods"><a name="id515868"></a><h2>Methods</h2><div class="refsect2" title="gio.InputStream.clear_pending"><a name="method-gioinputstream--clear-pending"></a><h3>gio.InputStream.clear_pending</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">clear_pending</span>(<span class="methodparam"></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody></tbody></table><p>
  20                 The <code class="methodname">clear_pending</code>() method clears the pending flag on stream.
  21             </p></div><div class="refsect2" title="gio.InputStream.close"><a name="method-gioinputstream--close"></a><h3>gio.InputStream.close</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">close</span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody><tr><td><p><span class="term"><strong class="parameter"><code>cancellable</code></strong> :</span></p></td><td>optional
  22                     <a class="link" href="class-giocancellable.html" title="gio.Cancellable"><code class="classname">gio.Cancellable</code></a>
  23                     object, <code class="literal">None</code> to ignore.
  24                   </td></tr><tr><td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td><td><code class="literal">True</code> on success
  25                     <code class="literal">False</code> on failure.
  26                     </td></tr></tbody></table><p>
  27                 The <code class="methodname">close</code>() method closes the stream, releasing
  28                 resources related to it.
  29             </p><p>
  30                 Once the stream is closed, all other operations will return gio.ERROR_CLOSED.
  31                 Closing a stream multiple times will not return an error.
  32             </p><p>
  33                 Streams will be automatically closed when the last reference is dropped, but
  34                 you might want to call this function to make sure resources are released as
  35                 early as possible.
  36             </p><p>
  37                 Some streams might keep the backing store of the stream (e.g. a file descriptor)
  38                 open after the stream is closed. See the documentation for the individual
  39                 stream for details.
  40             </p><p>
  41                 On failure the first error that happened will be reported, but the close operation
  42                 will finish as much as possible. A stream that failed to close will still return
  43                 gio.ERROR_CLOSED for all operations. Still, it is important to check and report
  44                 the error to the user.
  45             </p><p>
  46                 If cancellable is not <code class="literal">None</code>, then the operation can be cancelled by
  47                 triggering the cancellable object from another thread. If the operation was cancelled,
  48                 the error gio.ERROR_CANCELLED will be returned. Cancelling a close will still leave
  49                 the stream closed, but some streams can use a faster close that doesn't block to e.g.
  50                 check errors.
  51             </p></div><div class="refsect2" title="gio.InputStream.close_async"><a name="method-gioinputstream--close-async"></a><h3>gio.InputStream.close_async</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">close_async</span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>callback</code></strong></span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>io_priority</code></strong></span><span class="initializer">=glib.PRIORITY_DEFAULT</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>user_data</code></strong></span><span class="initializer">=None</span></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody><tr><td><p><span class="term"><em class="parameter"><code>callback</code></em> :</span></p></td><td>a GAsyncReadyCallback to call when the request is satisfied.
  52                     </td></tr><tr><td><p><span class="term"><em class="parameter"><code>io_priority</code></em> :</span></p></td><td>the
  53                     <a class="xref" href="glib-constants.html#glib-priority-constants" title="Glib Priority Constants">Glib Priority Constants</a>
  54                     of the request.
  55                     </td></tr><tr><td><p><span class="term"><em class="parameter"><code>cancellable</code></em> :</span></p></td><td>optional
  56                     <a class="link" href="class-giocancellable.html" title="gio.Cancellable"><code class="classname">gio.Cancellable</code></a>
  57                     object, <code class="literal">None</code> to ignore.</td></tr><tr><td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td><td>the data to pass to callback function.
  58                     </td></tr></tbody></table><p>
  59                 The <code class="methodname">close_async</code>() method asynchronously requests an
  60                 asynchronous closes of the stream, releasing resources related to it.
  61             </p><p>
  62                 For more details, see
  63                 <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--close" title="gio.InputStream.close">gio.InputStream.close</a></code>()
  64                 which is the synchronous version of this call.
  65             </p><p>
  66                 When the operation is finished, callback will be called. You can then call
  67                 <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--close-finish" title="gio.InputStream.close_finish">gio.InputStream.close_finish</a></code>()
  68                 to get the result of the operation.
  69             </p></div><div class="refsect2" title="gio.InputStream.close_finish"><a name="method-gioinputstream--close-finish"></a><h3>gio.InputStream.close_finish</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">close_finish</span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>result</code></strong></span></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody><tr><td><p><span class="term"><strong class="parameter"><code>result</code></strong> :</span></p></td><td>a <a class="link" href="class-gioasyncresult.html" title="gio.AsyncResult"><code class="classname">gio.AsyncResult</code></a>.
  70                   </td></tr><tr><td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td><td><code class="literal">True</code> if the stream was closed successfully.
  71                     </td></tr></tbody></table><p>
  72                 The <code class="methodname">close_finish</code>() method finishes an asynchronous
  73                 file append operation started with
  74                 <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--close-async" title="gio.InputStream.close_async">gio.InputStream.close_async</a></code>().
  75             </p></div><div class="refsect2" title="gio.InputStream.has_pending"><a name="method-gioinputstream--has-pending"></a><h3>gio.InputStream.has_pending</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">has_pending</span>(<span class="methodparam"></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody><tr><td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td><td><code class="literal">True</code> if stream has pending actions.
  76                     </td></tr></tbody></table><p>
  77                 The <code class="methodname">has_pending</code>() method checks if an input stream has pending actions.
  78             </p></div><div class="refsect2" title="gio.InputStream.is_closed"><a name="method-gioinputstream--is-closed"></a><h3>gio.InputStream.is_closed</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">is_closed</span>(<span class="methodparam"></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody><tr><td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td><td><code class="literal">True</code> if the stream is closed.
  79                     </td></tr></tbody></table><p>
  80                 The <code class="methodname">is_closed</code>() method checks if an input stream is closed.
  81             </p></div><div class="refsect2" title="gio.InputStream.read"><a name="method-gioinputstream--read"></a><h3>gio.InputStream.read</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">read</span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>count</code></strong></span><span class="initializer">=-1</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody><tr><td><p><span class="term"><strong class="parameter"><code>count</code></strong> :</span></p></td><td>optionally the number of bytes that will be read from the stream.
  82                   </td></tr><tr><td><p><span class="term"><strong class="parameter"><code>cancellable</code></strong> :</span></p></td><td>optional
  83                     <a class="link" href="class-giocancellable.html" title="gio.Cancellable"><code class="classname">gio.Cancellable</code></a>
  84                     object, <code class="literal">None</code> to ignore.
  85                   </td></tr><tr><td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td><td>The number of bytes read, or -1 on error.
  86                     </td></tr></tbody></table><p>
  87                 The <code class="methodname">read</code>() method tries to read count bytes from
  88                 the stream into the buffer starting at buffer. Will block during this read.
  89             </p><p>
  90                 This function is similar to
  91                 <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--read-part" title="gio.InputStream.read_part">gio.InputStream.read_part</a></code>(),
  92                 except it tries to read as many bytes as requested, only stopping on an error or end of stream.
  93             </p><p>
  94                 On a successful read of count bytes, or if we reached the end of the stream,
  95                 <code class="literal">True</code> is returned, and bytes_read is set to the number of bytes read into buffer.
  96             </p><p>
  97                 If cancellable is not <code class="literal">None</code>, then the operation can be cancelled by
  98                 triggering the cancellable object from another thread. If the operation was cancelled,
  99                 the error gio.ERROR_CANCELLED will be returned. Cancelling a close will still leave
 100                 the stream closed, but some streams can use a faster close that doesn't block to e.g.
 101                 check errors.
 102             </p><p>
 103                 If there is an error during the operation <code class="literal">False</code> is returned and error
 104                 is set to indicate the error status, bytes_read is updated to contain the number of
 105                 bytes read into buffer before the error occurred.
 106             </p></div><div class="refsect2" title="gio.InputStream.read_async"><a name="method-gioinputstream--read-async"></a><h3>gio.InputStream.read_async</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">read_async</span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>count</code></strong></span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>callback</code></strong></span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>io_priority</code></strong></span><span class="initializer">=glib.PRIORITY_DEFAULT</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>user_data</code></strong></span><span class="initializer">=None</span></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody><tr><td><p><span class="term"><em class="parameter"><code>count</code></em> :</span></p></td><td>the number of bytes that will be read from the stream.
 107                     </td></tr><tr><td><p><span class="term"><em class="parameter"><code>callback</code></em> :</span></p></td><td>a GAsyncReadyCallback to call when the request is satisfied.
 108                     </td></tr><tr><td><p><span class="term"><em class="parameter"><code>io_priority</code></em> :</span></p></td><td>the
 109                     <a class="xref" href="glib-constants.html#glib-priority-constants" title="Glib Priority Constants">Glib Priority Constants</a>
 110                     of the request.
 111                     </td></tr><tr><td><p><span class="term"><em class="parameter"><code>cancellable</code></em> :</span></p></td><td>optional
 112                     <a class="link" href="class-giocancellable.html" title="gio.Cancellable"><code class="classname">gio.Cancellable</code></a>
 113                     object, <code class="literal">None</code> to ignore.</td></tr><tr><td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td><td>the data to pass to callback function.
 114                     </td></tr></tbody></table><p>
 115                 The <code class="methodname">read_async</code>() method requests an asynchronous read
 116                 of count bytes from the stream into the buffer.
 117             </p><p>
 118                 For more details, see
 119                 <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--read" title="gio.InputStream.read">gio.InputStream.read</a></code>()
 120                 which is the synchronous version of this call.
 121             </p><p>
 122                 When the operation is finished, callback will be called. You can then call
 123                 <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--read-finish" title="gio.InputStream.read_finish">gio.InputStream.read_finish</a></code>()
 124                 to get the result of the operation.
 125             </p><p>
 126                 During an async request no other sync and async calls are allowed, and
 127                 will result in gio.ERROR_PENDING errors.
 128             </p><p>
 129                 A value of count larger than G_MAXSSIZE will cause a gio.ERROR_INVALID_ARGUMENT error.
 130             </p><p>
 131                 On success, the number of bytes read into the buffer will be passed to the callback.
 132                 It is not an error if this is not the same as the requested size, as it can happen e.g.
 133                 near the end of a file, but generally we try to read as many bytes as requested. Zero
 134                 is returned on end of file (or if count is zero), but never otherwise.
 135             </p><p>
 136                 Any outstanding i/o request with higher priority (lower numerical value) will be
 137                 executed before an outstanding request with lower priority. Default priority is glib.PRIORITY_DEFAULT.
 138             </p><p>
 139                 The asyncronous methods have a default fallback that uses threads to implement asynchronicity, so
 140                 they are optional for inheriting classes. However, if you override one you must override all.
 141             </p></div><div class="refsect2" title="gio.InputStream.read_finish"><a name="method-gioinputstream--read-finish"></a><h3>gio.InputStream.read_finish</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">read_finish</span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>result</code></strong></span></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody><tr><td><p><span class="term"><strong class="parameter"><code>result</code></strong> :</span></p></td><td>a <a class="link" href="class-gioasyncresult.html" title="gio.AsyncResult"><code class="classname">gio.AsyncResult</code></a>.
 142                   </td></tr><tr><td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td><td>The number of bytes read in, or -1 on error.
 143                     </td></tr></tbody></table><p>
 144                 The <code class="methodname">read_finish</code>() method finishes an asynchronous
 145                 stream read operation started by
 146                 <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--read-async" title="gio.InputStream.read_async">gio.InputStream.read_async</a></code>().
 147             </p></div><div class="refsect2" title="gio.InputStream.read_part"><a name="method-gioinputstream--read-part"></a><h3>gio.InputStream.read_part</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">read_part</span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>count</code></strong></span><span class="initializer">=-1</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody><tr><td><p><span class="term"><strong class="parameter"><code>count</code></strong> :</span></p></td><td>optionally the number of bytes that will be read from the stream.
 148                   </td></tr><tr><td><p><span class="term"><strong class="parameter"><code>cancellable</code></strong> :</span></p></td><td>optional
 149                     <a class="link" href="class-giocancellable.html" title="gio.Cancellable"><code class="classname">gio.Cancellable</code></a>
 150                     object, <code class="literal">None</code> to ignore.
 151                   </td></tr><tr><td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td><td>The number of bytes read, or -1 on error.
 152                     </td></tr></tbody></table><p>
 153                 The <code class="methodname">read_part</code>() method tries to read count bytes from
 154                 the stream into the buffer starting at buffer. Will block during this read.
 155             </p><p>
 156                 If count is zero returns zero and does nothing. A value of count larger than
 157                 G_MAXSSIZE will cause a gio.ERROR_INVALID_ARGUMENT error.
 158             </p><p>
 159                 On success, the number of bytes read into the buffer is returned. It is
 160                 not an error if this is not the same as the requested size, as it can
 161                 happen e.g. near the end of a file. Zero is returned on end of file
 162                 (or if count is zero), but never otherwise.
 163             </p><p>
 164                If cancellable is not <code class="literal">None</code>, then the operation can be cancelled by
 165                 triggering the cancellable object from another thread. If the operation was cancelled,
 166                 the error gio.ERROR_CANCELLED will be returned. Cancelling a close will still leave
 167                 the stream closed, but some streams can use a faster close that doesn't block to e.g.
 168                 check errors.
 169             </p><p>
 170                 On error -1 is returned and error is set accordingly.
 171             </p><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3>
 172                 This method roughly corresponds to C GIO g_input_stream_read.
 173             </div></div><div class="refsect2" title="gio.InputStream.set_pending"><a name="method-gioinputstream--set-pending"></a><h3>gio.InputStream.set_pending</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">set_pending</span>(<span class="methodparam"></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody><tr><td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td><td><code class="literal">True</code> if pending was previously
 174                     unset and is now set.
 175                     </td></tr></tbody></table><p>
 176                 The <code class="methodname">set_pending</code>() method sets stream to have actions pending.
 177                 If the pending flag is already set or stream is closed,
 178                 it will return <code class="literal">False</code> and set error.
 179             </p></div><div class="refsect2" title="gio.InputStream.skip"><a name="method-gioinputstream--skip"></a><h3>gio.InputStream.skip</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">skip</span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>count</code></strong></span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody><tr><td><p><span class="term"><strong class="parameter"><code>count</code></strong> :</span></p></td><td>the number of bytes that will be skipped from the stream.
 180                   </td></tr><tr><td><p><span class="term"><strong class="parameter"><code>cancellable</code></strong> :</span></p></td><td>optional
 181                     <a class="link" href="class-giocancellable.html" title="gio.Cancellable"><code class="classname">gio.Cancellable</code></a>
 182                     object, <code class="literal">None</code> to ignore.
 183                   </td></tr><tr><td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td><td>The number of bytes skipped, or -1 on error
 184                     </td></tr></tbody></table><p>
 185                 The <code class="methodname">skip</code>() method tries to skip count bytes
 186                 from the stream. Will block during the operation.
 187             </p><p>
 188                 This is identical to
 189                 <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--read" title="gio.InputStream.read">read</a></code>(),
 190                 from a behaviour standpoint, but the bytes that are skipped are not
 191                 returned to the user. Some streams have an implementation that is more
 192                 efficient than reading the data.
 193             </p><p>
 194                 This function is optional for inherited classes, as the default implementation emulates it using read.
 195             </p><p>
 196                If cancellable is not <code class="literal">None</code>, then the operation can be cancelled by
 197                 triggering the cancellable object from another thskip. If the operation was cancelled,
 198                 the error gio.ERROR_CANCELLED will be returned. Cancelling a close will still leave
 199                 the stream closed, but some streams can use a faster close that doesn't block to e.g.
 200                 check errors.
 201             </p></div><div class="refsect2" title="gio.InputStream.skip_async"><a name="method-gioinputstream--skip-async"></a><h3>gio.InputStream.skip_async</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">skip_async</span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>count</code></strong></span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>callback</code></strong></span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>io_priority</code></strong></span><span class="initializer">=glib.PRIORITY_DEFAULT</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>cancellable</code></strong></span><span class="initializer">=None</span></span>, <span class="methodparam"><span class="parameter"><strong class="parameter"><code>user_data</code></strong></span><span class="initializer">=None</span></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody><tr><td><p><span class="term"><em class="parameter"><code>count</code></em> :</span></p></td><td>the number of bytes that will be skipped from the stream.
 202                     </td></tr><tr><td><p><span class="term"><em class="parameter"><code>callback</code></em> :</span></p></td><td>a GAsyncskipyCallback to call when the request is satisfied.
 203                     </td></tr><tr><td><p><span class="term"><em class="parameter"><code>io_priority</code></em> :</span></p></td><td>the
 204                     <a class="xref" href="glib-constants.html#glib-priority-constants" title="Glib Priority Constants">Glib Priority Constants</a>
 205                     of the request.
 206                     </td></tr><tr><td><p><span class="term"><em class="parameter"><code>cancellable</code></em> :</span></p></td><td>optional
 207                     <a class="link" href="class-giocancellable.html" title="gio.Cancellable"><code class="classname">gio.Cancellable</code></a>
 208                     object, <code class="literal">None</code> to ignore.</td></tr><tr><td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td><td>the data to pass to callback function.
 209                     </td></tr></tbody></table><p>
 210                 The <code class="methodname">skip_async</code>() method request an asynchronous
 211                 skip of count bytes from the stream.
 212             </p><p>
 213                 For more details, see
 214                 <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--skip" title="gio.InputStream.skip">gio.InputStream.skip</a></code>()
 215                 which is the synchronous version of this call.
 216             </p><p>
 217                 When the operation is finished, callback will be called. You can then call
 218                 <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--skip-finish" title="gio.InputStream.skip_finish">gio.InputStream.skip_finish</a></code>()
 219                 to get the result of the operation.
 220             </p><p>
 221                 During an async request no other sync and async calls are allowed, and
 222                 will result in gio.ERROR_PENDING errors.
 223             </p><p>
 224                 A value of count larger than G_MAXSSIZE will cause a gio.ERROR_INVALID_ARGUMENT error.
 225             </p><p>
 226                 On success, the number of bytes skipped will be passed to the callback. It is
 227                 not an error if this is not the same as the requested size, as it can happen
 228                 e.g. near the end of a file, but generally we try to skip as many bytes as requested.
 229                 Zero is returned on end of file (or if count is zero), but never otherwise.
 230             </p><p>
 231                 Any outstanding i/o request with higher priority (lower numerical value) will be
 232                 executed before an outstanding request with lower priority. Default priority is glib.PRIORITY_DEFAULT.
 233             </p><p>
 234                 The asyncronous methods have a default fallback that uses thskips to implement asynchronicity, so
 235                 they are optional for inheriting classes. However, if you override one you must override all.
 236             </p></div><div class="refsect2" title="gio.InputStream.skip_finish"><a name="method-gioinputstream--skip-finish"></a><h3>gio.InputStream.skip_finish</h3><pre class="programlisting"><code class="methodsynopsis">    def <span class="methodname">skip_finish</span>(<span class="methodparam"><span class="parameter"><strong class="parameter"><code>result</code></strong></span></span>)</code></pre><table border="0" width="100%" bgcolor="#FFECCE"><col align="left" valign="top" width="0*"><tbody><tr><td><p><span class="term"><strong class="parameter"><code>result</code></strong> :</span></p></td><td>a <a class="link" href="class-gioasyncresult.html" title="gio.AsyncResult"><code class="classname">gio.AsyncResult</code></a>.
 237                   </td></tr><tr><td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td><td>The number of bytes skipped in, or -1 on error.
 238                     </td></tr></tbody></table><p>
 239                 The <code class="methodname">skip_finish</code>() method finishes an asynchronous
 240                 stream skip operation started by
 241                 <code class="methodname"><a class="link" href="class-gioinputstream.html#method-gioinputstream--skip-async" title="gio.InputStream.skip_async">gio.InputStream.skip_async</a></code>().
 242             </p></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="class-gioicon.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="gio-class-reference.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="class-gioloadableicon.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">gio.Icon </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> gio.LoadableIcon</td></tr></table></div></body></html>