X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/mLib/blobdiff_plain/76a6457a1244e6ec178da144bf9b854b169095dd..53e76188bd5fdc56afd5df70d4c0b2ddf330b9d7:/tv.h

diff --git a/tv.h b/tv.h
index 60bcfdf..a963e17 100644
--- a/tv.h
+++ b/tv.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: tv.h,v 1.4 1999/05/17 20:37:25 mdw Exp $
+ * $Id: tv.h,v 1.5 1999/05/21 22:13:12 mdw Exp $
  *
  * Manipulation of timeval structures
  *
@@ -30,6 +30,10 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: tv.h,v $
+ * Revision 1.5  1999/05/21 22:13:12  mdw
+ * Moved most of the code into exported macros.  The main functions now
+ * implemented using the macros.
+ *
  * Revision 1.4  1999/05/17 20:37:25  mdw
  * New function `tv_addl' to add a literal to a time value.
  *
@@ -55,6 +59,10 @@
 
 #include <sys/time.h>
 
+/*----- A macro to make reading easier ------------------------------------*/
+
+#define MILLION 1000000
+
 /*----- Functions provided ------------------------------------------------*/
 
 /* --- @tv_add@ --- *
@@ -71,6 +79,8 @@ extern void tv_add(struct timeval */*dst*/,
 		   const struct timeval */*a*/,
 		   const struct timeval */*b*/);
 
+#define TV_ADD(dst, a, b) TV_ADDL(dst, a, (b)->tv_sec, (b)->tv_usec)
+
 /* --- @tv_addl@ --- *
  *
  * Arguments:	@struct timeval *dst@ = destination block
@@ -86,6 +96,15 @@ extern void tv_addl(struct timeval */*dst*/,
 		    const struct timeval */*a*/,
 		    time_t /*sec*/, unsigned long /*usec*/);
 
+#define TV_ADDL(dst, a, sec, usec) do {					\
+  (dst)->tv_sec = (a)->tv_sec + (sec);					\
+  (dst)->tv_usec = (a)->tv_usec + (usec);				\
+  if ((dst)->tv_usec >= MILLION) {					\
+    (dst)->tv_usec -= MILLION;						\
+    (dst)->tv_sec++;							\
+  }									\
+} while (0)
+
 /* --- @tv_sub@ --- *
  *
  * Arguments:	@struct timeval *dst@ = destination block
@@ -100,6 +119,33 @@ extern void tv_sub(struct timeval */*dst*/,
 		   const struct timeval */*a*/,
 		   const struct timeval */*b*/);
 
+#define TV_SUB(dst, a, b) TV_SUBL(dst, a, (b)->tv_sec, (b)->tv_usec)
+
+/* --- @tv_subl@ --- *
+ *
+ * Arguments:	@struct timeval *dst@ = destination block
+ *		@const struct timeval *a@ = source blocks
+ *		@time_t sec@, @unsigned long usec@ = time to subtract
+ *
+ * Returns:	---
+ *
+ * Use:		Subtracts a literal time in seconds and microseconds.
+ */
+
+extern void tv_subl(struct timeval */*dst*/,
+		    const struct timeval */*a*/,
+		    time_t /*sec*/, unsigned long /*usec*/);
+
+#define TV_SUBL(dst, a, sec, usec) do {					\
+  (dst)->tv_sec = (a)->tv_sec - (sec);					\
+  if ((a)->tv_usec >= (usec))						\
+    (dst)->tv_usec = (a)->tv_usec - (usec);				\
+  else {								\
+    (dst)->tv_usec = (a)->tv_usec + MILLION - (usec);			\
+    (dst)->tv_sec--;							\
+  }									\
+} while (0)
+
 /* --- @tv_cmp@ --- *
  *
  * Arguments:	@const struct timeval *a, *b@ = source blocks
@@ -112,6 +158,10 @@ extern void tv_sub(struct timeval */*dst*/,
 extern int tv_cmp(const struct timeval */*a*/,
 		  const struct timeval */*b*/);
 
+#define TV_CMP(a, op, b) ((a)->tv_sec == (b)->tv_sec ?			\
+			    (a)->tv_usec op (b)->tv_usec :		\
+			    (a)->tv_sec op (b)->tv_sec)
+
 /*----- That's all, folks -------------------------------------------------*/
 
 #ifdef __cplusplus