Add interface for performing long tasks in background, while giving a

progress indication.

1 files changed, 103 insertions, 0 deletions

diff --git a/libdimension/progress.c b/libdimension/progress.c
new file mode 100644
index 0000000..e072f5d
--- /dev/null
+++ b/libdimension/progress.c
@@ -0,0 +1,103 @@
+/*************************************************************************
+ * Copyright (C) 2008 Tavian Barnes <tavianator@gmail.com>               *
+ *                                                                       *
+ * This file is part of The Dimension Library.                           *
+ *                                                                       *
+ * The Dimension Library is free software; you can redistribute it and/  *
+ * or modify it under the terms of the GNU Lesser General Public License *
+ * as published by the Free Software Foundation; either version 3 of the *
+ * License, or (at your option) any later version.                       *
+ *                                                                       *
+ * The Dimension Library is distributed in the hope that it will be      *
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty   *
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU  *
+ * Lesser General Public License for more details.                       *
+ *                                                                       *
+ * You should have received a copy of the GNU Lesser General Public      *
+ * License along with this program.  If not, see                         *
+ * <http://www.gnu.org/licenses/>.                                       *
+ *************************************************************************/
+
+#include "dimension.h"
+#include <pthread.h>
+#include <stdlib.h> /* For malloc */
+
+dmnsn_progress *
+dmnsn_new_progress()
+{
+  dmnsn_progress *progress = malloc(sizeof(dmnsn_progress));
+  if (progress) {
+    progress->elements = dmnsn_new_array(sizeof(dmnsn_progress_element));
+  }
+  return progress;
+}
+
+void
+dmnsn_delete_progress(dmnsn_progress *progress)
+{
+  if (progress) {
+    dmnsn_delete_array(progress->elements);
+    free(progress);
+  }
+}
+
+int dmnsn_finish_progress(dmnsn_progress *progress)
+{
+  void *ptr;
+  int retval = 1;
+
+  if (progress) {
+    if (pthread_join(progress->thread, &ptr) != 0) {
+      /* Medium severity because an unjoined thread likely means that the thread
+         is incomplete or invalid */
+      dmnsn_error(DMNSN_SEVERITY_MEDIUM, "Joining worker thread failed.");
+    } else if (ptr) {
+      retval = *(int *)ptr;
+      free(ptr);
+    }
+    dmnsn_delete_progress(progress);
+  }
+
+  return retval;
+}
+
+double
+dmnsn_get_progress(const dmnsn_progress* progress)
+{
+  dmnsn_progress_element *element;
+  double prog = 0.0;
+  unsigned int i;
+
+  dmnsn_array_rdlock(progress->elements);
+  for (i = 0; i < progress->elements->length; ++i) {
+    element = dmnsn_array_at(progress->elements,
+                             progress->elements->length - i - 1);
+    prog += element->progress;
+    prog /= element->total;
+  }
+  dmnsn_array_unlock(progress->elements);
+
+  return prog;
+}
+
+void
+dmnsn_new_progress_element(dmnsn_progress* progress, unsigned int total)
+{
+  dmnsn_progress_element element = { .progress = 0, .total = total };
+  dmnsn_array_push(progress->elements, &element);
+}
+
+void
+dmnsn_increment_progress(dmnsn_progress* progress)
+{
+  dmnsn_progress_element *element;
+
+  dmnsn_array_wrlock(progress->elements);
+  element = dmnsn_array_at(progress->elements, progress->elements->length - 1);
+  ++element->progress;
+  if (element->progress >= element->total) {
+    dmnsn_array_resize_unlocked(progress->elements,
+                                progress->elements->length - 1);
+  }
+  dmnsn_array_unlock(progress->elements);
+}