New event API (RHBZ#664558).

This API allows more than one callback to be registered for each
event, makes it possible to call the API from other languages, and
allows [nearly all] log, debug and trace messages to be rerouted from
stderr.

An older version of this API was discussed on the mailing list here:
https://www.redhat.com/archives/libguestfs/2010-December/msg00081.html
https://www.redhat.com/archives/libguestfs/2011-January/msg00012.html

This also updates guestfish to use the new API for its progress bars.

1 files changed, 89 insertions, 0 deletions

diff --git a/capitests/test-debug-to-file.c b/capitests/test-debug-to-file.c
new file mode 100644
index 00000000..6d1b619e
--- /dev/null
+++ b/capitests/test-debug-to-file.c
@@ -0,0 +1,89 @@
+/* libguestfs
+ * Copyright (C) 2011 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/* Test that we can use the new event API to capture all debugging
+ * messages to a file.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "guestfs.h"
+
+static void
+debug_to_file (guestfs_h *g,
+               void *opaque,
+               uint64_t event,
+               int event_handle,
+               int flags,
+               const char *buf, size_t buf_len,
+               const uint64_t *array, size_t array_len)
+{
+  FILE *fp = opaque;
+
+  fwrite (buf, 1, buf_len, fp);
+}
+
+int
+main (int argc, char *argv[])
+{
+  guestfs_h *g;
+  const char *filename = "test.log";
+  FILE *debugfp;
+
+  debugfp = fopen (filename, "w");
+  if (debugfp == NULL) {
+    perror (filename);
+    exit (EXIT_FAILURE);
+  }
+
+  g = guestfs_create ();
+  if (g == NULL) {
+    fprintf (stderr, "failed to create handle\n");
+    exit (EXIT_FAILURE);
+  }
+
+  if (guestfs_set_event_callback
+      (g, debug_to_file,
+       GUESTFS_EVENT_LIBRARY|GUESTFS_EVENT_APPLIANCE|GUESTFS_EVENT_TRACE,
+       0, debugfp) == -1)
+    exit (EXIT_FAILURE);
+
+  if (guestfs_set_verbose (g, 1) == -1)
+    exit (EXIT_FAILURE);
+
+  if (guestfs_set_trace (g, 1) == -1)
+    exit (EXIT_FAILURE);
+
+  if (guestfs_add_drive_opts (g, "/dev/null",
+                              GUESTFS_ADD_DRIVE_OPTS_FORMAT, "raw",
+                              GUESTFS_ADD_DRIVE_OPTS_READONLY, 1,
+                              -1) == -1)
+    exit (EXIT_FAILURE);
+
+  if (guestfs_launch (g) == -1)
+    exit (EXIT_FAILURE);
+
+  guestfs_close (g);
+
+  exit (EXIT_SUCCESS);
+}