[GNUnet-SVN] r11168 - in gnunet/src: include util

[gnunet]

Author: grothoff
Date: 2010-05-03 22:39:50 +0200 (Mon, 03 May 2010)
New Revision: 11168

Modified:
   gnunet/src/include/gnunet_time_lib.h
   gnunet/src/util/time.c
Log:
time subtract

Modified: gnunet/src/include/gnunet_time_lib.h
===================================================================
--- gnunet/src/include/gnunet_time_lib.h        2010-05-03 20:27:55 UTC (rev 
11167)
+++ gnunet/src/include/gnunet_time_lib.h        2010-05-03 20:39:50 UTC (rev 
11168)
@@ -314,7 +314,23 @@
                                                       GNUNET_TIME_Relative
                                                       duration);
 
+
 /**
+ * Subtract a given relative duration from the
+ * given start time.
+ *
+ * @param start some absolute time
+ * @param duration some relative time to subtract
+ * @return ZERO if start <= duration, or FOREVER if start time is FOREVER; 
start-duration otherwise
+ */
+struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_subtract (struct
+                                                          GNUNET_TIME_Absolute
+                                                          start,
+                                                          struct
+                                                          GNUNET_TIME_Relative
+                                                          duration);
+
+/**
  * Multiply relative time by a given factor.
  *
  * @param rel some duration

Modified: gnunet/src/util/time.c
===================================================================
--- gnunet/src/util/time.c      2010-05-03 20:27:55 UTC (rev 11167)
+++ gnunet/src/util/time.c      2010-05-03 20:39:50 UTC (rev 11168)
@@ -270,7 +270,34 @@
   return ret;
 }
 
+
 /**
+ * Subtract a given relative duration from the
+ * given start time.
+ *
+ * @param start some absolute time
+ * @param duration some relative time to subtract
+ * @return ZERO if start <= duration, or FOREVER if start time is FOREVER; 
start-duration otherwise
+ */
+struct GNUNET_TIME_Absolute 
+GNUNET_TIME_absolute_subtract (struct
+                              GNUNET_TIME_Absolute
+                              start,
+                              struct
+                              GNUNET_TIME_Relative
+                              duration)
+{
+  struct GNUNET_TIME_Absolute ret;
+  if (start.value <= duration.value)
+    return GNUNET_TIME_UNIT_ZERO_ABS;
+  if (start.value == GNUNET_TIME_UNIT_FOREVER_ABS.value)
+    return GNUNET_TIME_UNIT_FOREVER_ABS;
+  ret.value = start.value - duration.value;
+  return ret;
+}
+
+
+/**
  * Multiply relative time by a given factor.
  *
  * @return FOREVER if rel=FOREVER or on overflow; otherwise rel*factor