bufferlist: Various cleanups

Add new method to iterate a bufferlist without having to allocate an iterator.
Add convenience method for getting an item from the list based on the group and
index.
Remove redundant _do_data callback and method.
Update unit-tests and add some more for the new methods.

2 files changed, 177 insertions, 75 deletions

diff --git a/gst/gstbufferlist.c b/gst/gstbufferlist.c
index 02863ee54..20a2ef802 100644
--- a/gst/gstbufferlist.c
+++ b/gst/gstbufferlist.c
@@ -289,6 +289,127 @@ gst_buffer_list_n_groups (GstBufferList * list)
   return n;
 }
 
+/**
+ * gst_buffer_list_foreach:
+ * @list: a #GstBufferList
+ * @func: a #GstBufferListFunc to call
+ * @user_data: user data passed to @func
+ *
+ * Call @func with @data for each buffer in @list.
+ *
+ * @func can modify the passed buffer pointer or its contents. The return value
+ * of @func define if this function returns or if the remaining buffers in a
+ * group should be skipped.
+ */
+void
+gst_buffer_list_foreach (GstBufferList * list, GstBufferListFunc func,
+    gpointer user_data)
+{
+  GList *tmp, *next;
+  guint group, idx;
+  GstBufferListItem res;
+
+  g_return_if_fail (list != NULL);
+  g_return_if_fail (func != NULL);
+
+  next = list->buffers;
+  group = idx = 0;
+  while (next) {
+    GstBuffer *buffer;
+
+    tmp = next;
+    next = g_list_next (tmp);
+
+    buffer = tmp->data;
+
+    if (buffer == GROUP_START) {
+      group++;
+      idx = 0;
+      continue;
+    } else if (buffer == STOLEN)
+      continue;
+    else
+      idx++;
+
+    /* need to decrement the indices */
+    res = func (&buffer, group - 1, idx - 1, user_data);
+
+    if (G_UNLIKELY (buffer != tmp->data)) {
+      /* the function changed the buffer */
+      if (buffer == NULL) {
+        /* we were asked to remove the item */
+        list->buffers = g_list_delete_link (list->buffers, tmp);
+        idx--;
+      } else {
+        /* change the buffer */
+        tmp->data = buffer;
+      }
+    }
+
+    switch (res) {
+      case GST_BUFFER_LIST_CONTINUE:
+        break;
+      case GST_BUFFER_LIST_SKIP_GROUP:
+        while (next && next->data != GROUP_START)
+          next = g_list_next (next);
+        break;
+      case GST_BUFFER_LIST_END:
+        return;
+    }
+  }
+}
+
+/**
+ * gst_buffer_list_get:
+ * @list: a #GstBufferList
+ * @group: the group
+ * @idx: the index in @group
+ *
+ * Get the buffer at @idx in @group.
+ *
+ * Note that this function is not efficient for iterating over the entire list.
+ * Use and iterator or gst_buffer_list_foreach() instead.
+ *
+ * Returns: the buffer at @idx in @group or NULL when there is no buffer. The
+ * buffer remaing valid as long as @list is valid.
+ */
+GstBuffer *
+gst_buffer_list_get (GstBufferList * list, guint group, guint idx)
+{
+  GList *tmp;
+  guint cgroup, cidx;
+
+  g_return_val_if_fail (list != NULL, NULL);
+
+  tmp = list->buffers;
+  cgroup = 0;
+  while (tmp) {
+    if (tmp->data == GROUP_START) {
+      if (cgroup == group) {
+        /* we found the group */
+        tmp = g_list_next (tmp);
+        cidx = 0;
+        while (tmp && tmp->data != GROUP_START) {
+          if (tmp->data != STOLEN) {
+            if (cidx == idx)
+              return GST_BUFFER_CAST (tmp->data);
+            else
+              cidx++;
+          }
+          tmp = g_list_next (tmp);
+        }
+        break;
+      } else {
+        cgroup++;
+        if (cgroup > group)
+          break;
+      }
+    }
+    tmp = g_list_next (tmp);
+  }
+  return NULL;
+}
+
 GType
 gst_buffer_list_get_type (void)
 {
@@ -474,9 +595,10 @@ gst_buffer_list_iterator_next (GstBufferListIterator * it)
   return buffer;
 
 no_buffer:
-  it->last_returned = NULL;
-
-  return NULL;
+  {
+    it->last_returned = NULL;
+    return NULL;
+  }
 }
 
 /**
@@ -590,11 +712,10 @@ gst_buffer_list_iterator_steal (GstBufferListIterator * it)
 }
 
 /**
- * gst_buffer_list_iterator_do_data:
+ * gst_buffer_list_iterator_do:
  * @it: a #GstBufferListIterator
  * @do_func: the function to be called
- * @data: the gpointer to optional user data.
- * @data_notify: function to be called when @data is no longer used
+ * @user_data: the gpointer to optional user data.
  *
  * Calls the given function for the last buffer returned by
  * gst_buffer_list_iterator_next(). gst_buffer_list_iterator_next() must have
@@ -604,15 +725,11 @@ gst_buffer_list_iterator_steal (GstBufferListIterator * it)
  *
  * See #GstBufferListDoFunction for more details.
  *
- * The @data_notify function is called after @do_func has returned, before this
- * function returns, usually used to free @data.
- *
  * Returns: the return value from @do_func
  */
 GstBuffer *
-gst_buffer_list_iterator_do_data (GstBufferListIterator * it,
-    GstBufferListDoDataFunction do_func, gpointer data,
-    GDestroyNotify data_notify)
+gst_buffer_list_iterator_do (GstBufferListIterator * it,
+    GstBufferListDoFunction do_func, gpointer user_data)
 {
   GstBuffer *buffer;
 
@@ -624,56 +741,16 @@ gst_buffer_list_iterator_do_data (GstBufferListIterator * it,
   g_assert (it->last_returned->data != GROUP_START);
 
   buffer = gst_buffer_list_iterator_steal (it);
-  buffer = do_func (buffer, data);
+  buffer = do_func (buffer, user_data);
   if (buffer == NULL) {
     gst_buffer_list_iterator_remove (it);
   } else {
     gst_buffer_list_iterator_take (it, buffer);
   }
 
-  if (data_notify != NULL) {
-    data_notify (data);
-  }
-
   return buffer;
 }
 
-static GstBuffer *
-do_func_no_data (GstBuffer * buffer, GstBufferListDoFunction do_func)
-{
-  return do_func (buffer);
-}
-
-/**
- * gst_buffer_list_iterator_do:
- * @it: a #GstBufferListIterator
- * @do_func: the function to be called
- *
- * Calls the given function for the last buffer returned by
- * gst_buffer_list_iterator_next(). gst_buffer_list_iterator_next() must have
- * been called on @it before this function is called.
- * gst_buffer_list_iterator_remove() or gst_buffer_list_iterator_steal() must
- * not have been called since the last call to gst_buffer_list_iterator_next().
- *
- * See #GstBufferListDoFunction for more details.
- *
- * Returns: the return value from @do_func
- */
-GstBuffer *
-gst_buffer_list_iterator_do (GstBufferListIterator * it,
-    GstBufferListDoFunction do_func)
-{
-  g_return_val_if_fail (it != NULL, NULL);
-  g_return_val_if_fail (it->last_returned != NULL, NULL);
-  g_return_val_if_fail (it->last_returned->data != STOLEN, NULL);
-  g_return_val_if_fail (do_func != NULL, NULL);
-  g_return_val_if_fail (gst_buffer_list_is_writable (it->list), NULL);
-  g_assert (it->last_returned->data != GROUP_START);
-
-  return gst_buffer_list_iterator_do_data (it,
-      (GstBufferListDoDataFunction) do_func_no_data, do_func, NULL);
-}
-
 /**
  * gst_buffer_list_iterator_merge_group:
  * @it: a #GstBufferListIterator
diff --git a/gst/gstbufferlist.h b/gst/gstbufferlist.h
index 5e3385ef5..392b338ad 100644
--- a/gst/gstbufferlist.h
+++ b/gst/gstbufferlist.h
@@ -42,6 +42,7 @@ typedef struct _GstBufferListIterator GstBufferListIterator;
 /**
  * GstBufferListDoFunction:
  * @buffer: the #GstBuffer
+ * @user_data: user data
  *
  * A function for accessing the last buffer returned by
  * gst_buffer_list_iterator_next(). The function can leave @buffer in the list,
@@ -58,29 +59,49 @@ typedef struct _GstBufferListIterator GstBufferListIterator;
  * Returns: the buffer to replace @buffer in the list, or NULL to remove @buffer
  * from the list
  */
-typedef GstBuffer* (*GstBufferListDoFunction) (GstBuffer * buffer);
+typedef GstBuffer* (*GstBufferListDoFunction) (GstBuffer * buffer, gpointer user_data);
 
 /**
- * GstBufferListDoDataFunction:
- * @buffer: the #GstBuffer
- * @data: the gpointer to optional user data.
- *
- * A function for accessing the last buffer returned by
- * gst_buffer_list_iterator_next(). The function can leave @buffer in the list,
- * replace @buffer in the list or remove @buffer from the list, depending on
- * the return value. If the function returns NULL, @buffer will be removed from
- * the list, otherwise @buffer will be replaced with the returned buffer.
- *
- * The last buffer returned by gst_buffer_list_iterator_next() will be replaced
- * with the buffer returned from the function. The function takes ownership of
- * @buffer and if a different value than @buffer is returned, @buffer must be
- * unreffed. If NULL is returned, the buffer will be removed from the list. The
- * list must be writable.
+ * GstBufferListItem:
+ * @GST_BUFFER_LIST_CONTINUE:   Retrieve next buffer
+ * @GST_BUFFER_LIST_SKIP_GROUP: Skip to next group
+ * @GST_BUFFER_LIST_REMOVE:     Remove the current buffer
+ * @GST_BUFFER_LIST_END:        End iteration
  *
- * Returns: the buffer to replace @buffer in the list, or NULL to remove @buffer
- * from the list
+ * The result of the #GstBufferListFunc.
  */
-typedef GstBuffer* (*GstBufferListDoDataFunction) (GstBuffer * buffer, gpointer data);
+typedef enum {
+  GST_BUFFER_LIST_CONTINUE,
+  GST_BUFFER_LIST_SKIP_GROUP,
+  GST_BUFFER_LIST_END
+} GstBufferListItem;
+
+/**
+ * GstBufferListFunc:
+ * @buffer: pointer the buffer
+ * @group: the group index of @buffer
+ * @idx: the index in @group of @buffer
+ * @user_data: user data passed to gst_buffer_list_foreach()
+ *
+ * A function that will be called from gst_buffer_list_foreach(). The @buffer
+ * field will point to a the reference of the buffer at @idx in @group.
+ *
+ * When this function returns #GST_BUFFER_LIST_CONTINUE, the next buffer will be
+ * returned. When #GST_BUFFER_LIST_SKIP_GROUP is returned, all remaining buffers
+ * in the current group will be skipped and the first buffer of the next group
+ * is returned (if any). When GST_BUFFER_LIST_END is returned,
+ * gst_buffer_list_foreach() will return.
+ *
+ * When @buffer is set to NULL, the item will be removed from the bufferlist.
+ * When @buffer has been made writable, the new buffer reference can be assigned
+ * to @buffer. This function is responsible for unreffing the old buffer when
+ * removing or modifying.
+ *
+ * Returns: a #GstBufferListItem
+ */
+typedef GstBufferListItem (*GstBufferListFunc)   (GstBuffer **buffer, guint group, guint idx,
+                                                  gpointer user_data);
+
 
 GType gst_buffer_list_get_type (void);
 
@@ -170,6 +191,11 @@ gst_buffer_list_copy (const GstBufferList * list)
 
 guint                    gst_buffer_list_n_groups              (GstBufferList *list);
 
+void                     gst_buffer_list_foreach               (GstBufferList *list,
+                                                                GstBufferListFunc func,
+								gpointer user_data);
+GstBuffer *              gst_buffer_list_get                   (GstBufferList *list, guint group, guint idx);
+
 /* iterator */
 GstBufferListIterator *  gst_buffer_list_iterate               (GstBufferList *list);
 void                     gst_buffer_list_iterator_free         (GstBufferListIterator *it);
@@ -184,9 +210,8 @@ void                     gst_buffer_list_iterator_remove       (GstBufferListIte
 GstBuffer *              gst_buffer_list_iterator_steal        (GstBufferListIterator *it);
 void                     gst_buffer_list_iterator_take         (GstBufferListIterator *it, GstBuffer *buffer);
 
-GstBuffer *              gst_buffer_list_iterator_do           (GstBufferListIterator *it, GstBufferListDoFunction do_func);
-GstBuffer *              gst_buffer_list_iterator_do_data      (GstBufferListIterator *it, GstBufferListDoDataFunction do_func,
-                                                                gpointer data, GDestroyNotify data_notify);
+GstBuffer *              gst_buffer_list_iterator_do           (GstBufferListIterator *it, GstBufferListDoFunction do_func,
+                                                                gpointer user_data);
 
 /* conversion */
 GstBuffer *              gst_buffer_list_iterator_merge_group  (const GstBufferListIterator *it);