Iterator

Object Hierarchy:

Description:

[ CCode ( copy_function = "gst_iterator_copy" , free_function = "gst_iterator_free" , type_id = "gst_iterator_get_type ()" ) ]
[ Compact ]
public class Iterator

A GstIterator is used to retrieve multiple objects from another object in a threadsafe way.

Various GStreamer objects provide access to their internal structures using an iterator.

Note that if calling a GstIterator function results in your code receiving a refcounted object (with, say, get_object), the refcount for that object will not be increased. Your code is responsible for taking a reference if it wants to continue using it later.

The basic use pattern of an iterator is as follows:

  GstIterator *it = _get_iterator(object);
  GValue item = G_VALUE_INIT;
  done = FALSE;
  while (!done) {
    switch (gst_iterator_next (it, &item)) {
      case GST_ITERATOR_OK:
        ...get/use/change item here...
        g_value_reset (&item);
        break;
      case GST_ITERATOR_RESYNC:
        ...rollback changes to items...
        gst_iterator_resync (it);
        break;
      case GST_ITERATOR_ERROR:
        ...wrong parameters were given...
        done = TRUE;
        break;
      case GST_ITERATOR_DONE:
        done = TRUE;
        break;
    }
  }
  g_value_unset (&item);
  gst_iterator_free (it);

Namespace: Gst

Package: gstreamer-1.0

Content:

Creation methods:

public Iterator.single (Type type, Value object)
This Iterator is a convenient iterator for the common case where a Iterator needs to be returned but only a single object has to be considered.

Methods:

public IteratorResult @foreach (IteratorForeachFunction func)
Iterate over all element of this and call the given function func for each element.
public Iterator copy ()
Copy the iterator and its state.
public Iterator filter<T> (SearchFunc<Value?,T> func, T user_data)
Create a new iterator from an existing iterator.
public bool find_custom<T> (SearchFunc<Value?,T> func, out Value elem, T user_data)
Find the first element in this that matches the compare function func.
public IteratorResult fold (IteratorFoldFunction func, ref Value ret)
Folds func over the elements of iter.
public void free ()
Free the iterator.
public IteratorResult next (out Value elem)
Get the next item from the iterator in elem.
public void push (Iterator other)
Pushes other iterator onto this .
public void resync ()
Resync the iterator.

Fields:

public Mutex @lock
public uint32 cookie
public unowned IteratorItemFunction item
public uint32 master_cookie
public unowned Iterator pushed
public uint size
public Type type