X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/mLib/blobdiff_plain/247239becbeb8f8f92d86e038de6315437679f71..9dc511e46d5acad665175981f824288062e27671:/tv.h

diff --git a/tv.h b/tv.h
index 99eb2d7..42750df 100644
--- a/tv.h
+++ b/tv.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: tv.h,v 1.1 1998/11/25 23:30:01 mdw Exp $
+ * $Id: tv.h,v 1.7 2004/04/08 01:36:13 mdw Exp $
  *
  * Manipulation of timeval structures
  *
@@ -12,30 +12,23 @@
  * This file is part of the mLib utilities library.
  *
  * mLib 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.
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
  * 
  * mLib 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.
+ * GNU Library General Public License for more details.
  * 
- * You should have received a copy of the GNU General Public License
- * along with mLib; if not, write to the Free Software Foundation,
- * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: tv.h,v $
- * Revision 1.1  1998/11/25 23:30:01  mdw
- * New file.
- *
- */
-
-#ifndef TV_H
-#define TV_H
+#ifndef MLIB_TV_H
+#define MLIB_TV_H
 
 #ifdef __cplusplus
   extern "C" {
@@ -45,6 +38,10 @@
 
 #include <sys/time.h>
 
+/*----- A macro to make reading easier ------------------------------------*/
+
+#define MILLION 1000000
+
 /*----- Functions provided ------------------------------------------------*/
 
 /* --- @tv_add@ --- *
@@ -61,6 +58,32 @@ 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
+ *		@const struct timeval *a@ = source blocks
+ *		@time_t sec@, @unsigned long usec@ = time to add
+ *
+ * Returns:	---
+ *
+ * Use:		Adds a literal time in seconds and microseconds.
+ */
+
+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
@@ -75,6 +98,33 @@ 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
@@ -87,6 +137,10 @@ 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