1 files changed, 153 insertions, 0 deletions
diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c
new file mode 100644
index 0000000000..d2ef112079
--- /dev/null
+++ b/src/common/compat_libevent.c
@@ -0,0 +1,153 @@
+/* Copyright (c) 2009, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file compat_libevent.c
+ * \brief Wrappers to handle porting between different versions of libevent.
+ *
+ * In an ideal world, we'd just use Libevent 2.0 from now on.  But as of June
+ * 2009, Libevent 2.0 is still in alpha, and we will have old versions of
+ * Libevent for the forseeable future.
+ **/
+
+#include "orconfig.h"
+#include "compat_libevent.h"
+
+#include "compat.h"
+#include "util.h"
+#include "log.h"
+
+#ifdef HAVE_EVENT2_EVENT_H
+#include <event2/event.h>
+#else
+#include <event.h>
+#endif
+
+#ifdef HAVE_EVENT_SET_LOG_CALLBACK
+/** A string which, if it appears in a libevent log, should be ignored. */
+static const char *suppress_msg = NULL;
+/** Callback function passed to event_set_log() so we can intercept
+ * log messages from libevent. */
+static void
+libevent_logging_callback(int severity, const char *msg)
+{
+  char buf[1024];
+  size_t n;
+  if (suppress_msg && strstr(msg, suppress_msg))
+    return;
+  n = strlcpy(buf, msg, sizeof(buf));
+  if (n && n < sizeof(buf) && buf[n-1] == '\n') {
+    buf[n-1] = '\0';
+  }
+  switch (severity) {
+    case _EVENT_LOG_DEBUG:
+      log(LOG_DEBUG, LD_NET, "Message from libevent: %s", buf);
+      break;
+    case _EVENT_LOG_MSG:
+      log(LOG_INFO, LD_NET, "Message from libevent: %s", buf);
+      break;
+    case _EVENT_LOG_WARN:
+      log(LOG_WARN, LD_GENERAL, "Warning from libevent: %s", buf);
+      break;
+    case _EVENT_LOG_ERR:
+      log(LOG_ERR, LD_GENERAL, "Error from libevent: %s", buf);
+      break;
+    default:
+      log(LOG_WARN, LD_GENERAL, "Message [%d] from libevent: %s",
+          severity, buf);
+      break;
+  }
+}
+/** Set hook to intercept log messages from libevent. */
+void
+configure_libevent_logging(void)
+{
+  event_set_log_callback(libevent_logging_callback);
+}
+/** Ignore any libevent log message that contains <b>msg</b>. */
+void
+suppress_libevent_log_msg(const char *msg)
+{
+  suppress_msg = msg;
+}
+#else
+void
+configure_libevent_logging(void)
+{
+}
+void
+suppress_libevent_log_msg(const char *msg)
+{
+  (void)msg;
+}
+#endif
+
+#ifndef HAVE_EVENT2_EVENT_H
+/** Work-alike replacement for event_new() on pre-Libevent-2.0 systems. */
+struct event *
+tor_event_new(struct event_base *base, int sock, short what,
+              void (*cb)(int, short, void *), void *arg)
+{
+  struct event *e = tor_malloc_zero(sizeof(struct event));
+  event_set(e, sock, what, cb, arg);
+  event_base_set(base, e);
+  return e;
+}
+/** Work-alike replacement for evtimer_new() on pre-Libevent-2.0 systems. */
+struct event *
+tor_evtimer_new(struct event_base *base,
+                void (*cb)(int, short, void *), void *arg)
+{
+  return tor_event_new(base, -1, 0, cb, arg);
+}
+/** Work-alike replacement for evsignal_new() on pre-Libevent-2.0 systems. */
+struct event *
+tor_evsignal_new(struct event_base * base, int sig,
+                 void (*cb)(int, short, void *), void *arg)
+{
+  return tor_event_new(base, sig, EV_SIGNAL, cb, arg);
+}
+/** Work-alike replacement for event_free() on pre-Libevent-2.0 systems. */
+void
+tor_event_free(struct event *ev)
+{
+  event_del(ev);
+  tor_free(ev);
+}
+#endif
+
+/** Global event base for use by the main thread. */
+struct event_base *the_event_base = NULL;
+
+/** Initialize the Libevent library and set up the event base. */
+void
+tor_libevent_initialize(void)
+{
+  tor_assert(the_event_base == NULL);
+#ifdef HAVE_EVENT2_EVENT_H
+  the_event_base = event_base_new();
+#else
+  the_event_base = event_init();
+#endif
+}
+
+/** Return the current Libevent event base that we're set up to use. */
+struct event_base *
+tor_libevent_get_base(void)
+{
+  return the_event_base;
+}
+
+/** Return the name of the Libevent backend we're using. */
+const char *
+tor_libevent_get_method(void)
+{
+#ifdef HAVE_EVENT2_EVENT_H
+  return event_base_get_method(the_event_base);
+#elif defined(HAVE_EVENT_GET_METHOD)
+  return event_get_method();
+#else
+  return "<unknown>";
+#endif
+}
+