repeat a node if child nodes get added to it

use common buffer for read and write action in test case

1 files changed, 52 insertions, 32 deletions

diff --git a/src/pop-transaction.c b/src/pop-transaction.c
index 2672ce2..011828a 100644
--- a/src/pop-transaction.c
+++ b/src/pop-transaction.c
@@ -133,6 +133,8 @@ struct _PopActionTree
 {
   GNode *root;
   GNode *current_action_node;
+  GNode *last_action_node;
+  guint has_new_nodes : 1;
 };
 
 static PopActionTree *pop_action_tree_new (void);
@@ -436,7 +438,7 @@ pop_action_tree_new (void)
 {
   PopActionTree *action_tree;
 
-  action_tree = g_slice_new (PopActionTree);
+  action_tree = g_slice_new0 (PopActionTree);
   action_tree->root = g_node_new (NULL);
 
   pop_action_tree_reset (action_tree);
@@ -448,6 +450,7 @@ static void
 pop_action_tree_reset (PopActionTree *action_tree)
 {
   action_tree->current_action_node = NULL;
+  action_tree->has_new_nodes = FALSE;
 }
 
 static gboolean 
@@ -519,14 +522,7 @@ pop_action_tree_walk_to_leaf (PopActionTree              *action_tree,
   node = current_node;
   while (node->children != NULL)
     {
-      if (direction == POP_ACTION_TREE_WALK_DIRECTION_FORWARD)
-        {
-          node = g_node_first_child (node);
-        }
-      else 
-        {
-          node = g_node_last_child (node);
-        }
+      node = g_node_first_child (node);
     }
 
   return node;
@@ -541,6 +537,22 @@ pop_action_tree_seek (PopActionTree              *action_tree,
   g_assert ((direction == POP_ACTION_TREE_WALK_DIRECTION_FORWARD)
             || (direction == POP_ACTION_TREE_WALK_DIRECTION_BACKWARD));
 
+  /* we got to backtrack a little if the node hierarchy changed out
+   * from under us.  Note by doing this, some nodes will get
+   * visited more than once, so the caller needs to check the
+   * action status and skip it if it's finished.  We could color
+   * the nodes to prevent revisiting nodes, but there isn't much
+   * point.
+   */
+  if (action_tree->has_new_nodes)
+    {
+      GNode *last_node;
+      last_node = action_tree->last_action_node;
+      action_tree->last_action_node = action_tree->current_action_node;
+      action_tree->current_action_node = last_node;
+      action_tree->has_new_nodes = FALSE;
+    }
+
   /* if current_action_node is NULL then we haven't started yet,
    * so set node to a child of the root. Otherwise, walk node
    * one step in the tree (to the next sibling, or the parent 
@@ -576,6 +588,7 @@ pop_action_tree_seek (PopActionTree              *action_tree,
   if (direction == POP_ACTION_TREE_WALK_DIRECTION_FORWARD)
     node = pop_action_tree_walk_to_leaf (action_tree, node, direction);
 
+  action_tree->last_action_node = action_tree->current_action_node;
   action_tree->current_action_node = node;
 
   return TRUE;
@@ -593,6 +606,8 @@ pop_action_tree_add_action (PopActionTree *action_tree,
     {
       g_node_insert_data (action_tree->root, -1, action);
     }
+
+  action_tree->has_new_nodes = TRUE;
 }
 
 static PopAction *
@@ -862,13 +877,11 @@ pop_transaction_process_action_and_seek_forward (PopTransaction *transaction)
 
   action = pop_action_tree_get_current_action (transaction->priv->action_tree);
 
-  if (action->process_status != POP_ACTION_PROCESS_STATUS_NOT_FINISHED)
-    return FALSE;
-
   transaction->priv->is_running_action = TRUE;
   if (action->process_func != NULL)
     {
-      action->process_status = action->process_func (transaction, action->user_data);
+      if (action->process_status == POP_ACTION_PROCESS_STATUS_NOT_FINISHED)
+        action->process_status = action->process_func (transaction, action->user_data);
     }
   else
     {
@@ -947,13 +960,11 @@ pop_transaction_rollback_action_and_rewind (PopTransaction *transaction)
 
   action = pop_action_tree_get_current_action (transaction->priv->action_tree);
 
-  if (action->rollback_status != POP_ACTION_ROLLBACK_STATUS_NOT_FINISHED)
-    return FALSE;
-
   transaction->priv->is_running_action = TRUE;
   if (action->rollback_func != NULL)
     {
-      action->rollback_status = action->rollback_func (transaction, action->user_data);
+      if (action->rollback_status == POP_ACTION_ROLLBACK_STATUS_NOT_FINISHED)
+        action->rollback_status = action->rollback_func (transaction, action->user_data);
     }
   else
     {
@@ -1376,7 +1387,7 @@ proces_io_action (PopTransaction       *transaction,
                                                  "is-ready"));
   if (!is_ready)
     {
-      g_print ("waiting for fd %d to become ready.\n", arguments->fd);
+      g_printerr ("waiting for fd %d to become ready.\n", arguments->fd);
       /* pause transaction until fd is ready for reading (or writing
        * depending on the io_func)
        */
@@ -1392,7 +1403,7 @@ proces_io_action (PopTransaction       *transaction,
       return POP_ACTION_PROCESS_STATUS_NOT_FINISHED;
     }
 
-  g_print ("fd %d is now ready!\n", arguments->fd);
+  g_printerr ("fd %d is now ready!\n", arguments->fd);
 
   bytes_done = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (transaction),
                                                    "bytes-already-processed"));
@@ -1405,18 +1416,26 @@ proces_io_action (PopTransaction       *transaction,
     {
       GError *error;
 
-      if ((errno == EINTR) || (errno == EAGAIN))
+      if (errno == EINTR)
         {
           return POP_ACTION_PROCESS_STATUS_NOT_FINISHED;
         }
+      else if (errno == EAGAIN)
+        {
+          pop_transaction_wait_for_fd (transaction, arguments->fd, condition,
+                                       NULL);
+          return POP_ACTION_PROCESS_STATUS_NOT_FINISHED;
+        }
+      else
+        {
+          error = g_error_new_literal (G_FILE_ERROR,
+                                       g_file_error_from_errno (errno),
+                                       g_strerror (errno));
 
-      error = g_error_new_literal (G_FILE_ERROR,
-                                   g_file_error_from_errno (errno),
-                                   g_strerror (errno));
-
-      pop_transaction_set_error (transaction, error);
-      g_error_free (error);
-      return POP_ACTION_PROCESS_STATUS_FAILED;
+          pop_transaction_set_error (transaction, error);
+          g_error_free (error);
+          return POP_ACTION_PROCESS_STATUS_FAILED;
+        }
     }
 
   g_assert (bytes_done_this_time <= bytes_left);
@@ -1456,7 +1475,7 @@ static PopActionProcessStatus
 process_read_action (PopTransaction *transaction,
                      gpointer        arguments)
 {
-  g_print ("processing read action\n");
+  g_printerr ("processing read action\n");
   return proces_io_action (transaction, (InputOutputFunc) read,
                            arguments, G_IO_IN);
 }
@@ -1465,7 +1484,7 @@ static PopActionProcessStatus
 process_write_action (PopTransaction *transaction,
                       gpointer        arguments)
 {
-  g_print ("processing write action\n");
+  g_printerr ("processing write action\n");
   return proces_io_action (transaction, (InputOutputFunc) write,
                            arguments, G_IO_OUT);
 }
@@ -1475,7 +1494,7 @@ process_cat_action (PopTransaction  *transaction,
                     gpointer         data)
 {
   char *buffer;
-  static const size_t buffer_size = 4096 * 10;
+  static const size_t buffer_size = 10;
   InputOutputArguments *input_arguments, *output_arguments;
 
   fcntl (STDIN_FILENO, F_SETFL, O_NONBLOCK);
@@ -1483,7 +1502,7 @@ process_cat_action (PopTransaction  *transaction,
 
   input_arguments = g_slice_new (InputOutputArguments);
   input_arguments->fd = STDIN_FILENO; 
-  input_arguments->buffer = g_malloc (buffer_size);
+  input_arguments->buffer = g_malloc0 (buffer_size);
   input_arguments->number_of_bytes_to_process = buffer_size;
 
   pop_transaction_add_action (transaction, process_read_action, 
@@ -1492,7 +1511,7 @@ process_cat_action (PopTransaction  *transaction,
 
   output_arguments = g_slice_new (InputOutputArguments);
   output_arguments->fd = STDOUT_FILENO; 
-  output_arguments->buffer = g_malloc (buffer_size);
+  output_arguments->buffer = input_arguments->buffer;
   output_arguments->number_of_bytes_to_process = buffer_size;
 
   pop_transaction_add_action (transaction, process_write_action, NULL,
@@ -1514,6 +1533,7 @@ rollback_cat_action (PopTransaction  *transaction,
 
   output_arguments = g_object_get_data (G_OBJECT (transaction), "cat-output-args");
   g_slice_free (InputOutputArguments, output_arguments);
+  g_free (output_arguments->buffer);
   g_object_set_data (G_OBJECT (transaction), "cat-input-args", NULL);
 
   return POP_ACTION_ROLLBACK_STATUS_FINISHED;