Move the "instr_time" typedef and associated macros into a new header

file portability/instr_time.h, and add a couple more macros to eliminate
some abstraction leakage we formerly had.  Also update psql to use this
header instead of its own copy of nearly the same code.

This commit in itself is just code cleanup and shouldn't change anything.
It lays some groundwork for the upcoming function-stats patch, though.

1 files changed, 139 insertions, 0 deletions

diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h
new file mode 100644
index 0000000000..666d495f20
--- /dev/null
+++ b/src/include/portability/instr_time.h
@@ -0,0 +1,139 @@
+/*-------------------------------------------------------------------------
+ *
+ * instr_time.h
+ *	  portable high-precision interval timing
+ *
+ * This file provides an abstraction layer to hide portability issues in
+ * interval timing.  On Unix we use gettimeofday(), but on Windows that
+ * gives a low-precision result so we must use QueryPerformanceCounter()
+ * instead.  These macros also give some breathing room to use other
+ * high-precision-timing APIs on yet other platforms.
+ *
+ * The basic data type is instr_time, which all callers should treat as an
+ * opaque typedef.  instr_time can store either an absolute time (of
+ * unspecified reference time) or an interval.  The operations provided
+ * for it are:
+ *
+ * INSTR_TIME_IS_ZERO(t)			is t equal to zero?
+ *
+ * INSTR_TIME_SET_ZERO(t)			set t to zero (memset is acceptable too)
+ *
+ * INSTR_TIME_SET_CURRENT(t)		set t to current time
+ *
+ * INSTR_TIME_SUBTRACT(x, y)		x -= y
+ *
+ * INSTR_TIME_ACCUM_DIFF(x, y, z)	x += (y - z)
+ *
+ * INSTR_TIME_GET_DOUBLE(t)			convert t to double (in seconds)
+ *
+ * INSTR_TIME_GET_MILLISEC(t)		convert t to double (in milliseconds)
+ *
+ * INSTR_TIME_GET_MICROSEC(t)		convert t to uint64 (in microseconds)
+ *
+ * Note that INSTR_TIME_SUBTRACT and INSTR_TIME_ACCUM_DIFF convert
+ * absolute times to intervals.  The INSTR_TIME_GET_xxx operations are
+ * only useful on intervals.
+ *
+ * When summing multiple measurements, it's recommended to leave the
+ * running sum in instr_time form (ie, use INSTR_TIME_ACCUM_DIFF) and
+ * convert to a result format only at the end.
+ *
+ * Beware of multiple evaluations of the macro arguments.
+ *
+ *
+ * Copyright (c) 2001-2008, PostgreSQL Global Development Group
+ *
+ * $PostgreSQL: pgsql/src/include/portability/instr_time.h,v 1.1 2008/05/14 19:10:29 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef INSTR_TIME_H
+#define INSTR_TIME_H
+
+#ifndef WIN32
+
+#include <sys/time.h>
+
+typedef struct timeval instr_time;
+
+#define INSTR_TIME_IS_ZERO(t)	((t).tv_usec == 0 && (t).tv_sec == 0)
+
+#define INSTR_TIME_SET_ZERO(t)	((t).tv_sec = 0, (t).tv_usec = 0)
+
+#define INSTR_TIME_SET_CURRENT(t)	gettimeofday(&(t), NULL)
+
+#define INSTR_TIME_SUBTRACT(x,y) \
+	do { \
+		(x).tv_sec -= (y).tv_sec; \
+		(x).tv_usec -= (y).tv_usec; \
+		/* Normalize */ \
+		while ((x).tv_usec < 0) \
+		{ \
+			(x).tv_usec += 1000000; \
+			(x).tv_sec--; \
+		} \
+	} while (0)
+
+#define INSTR_TIME_ACCUM_DIFF(x,y,z) \
+	do { \
+		(x).tv_sec += (y).tv_sec - (z).tv_sec; \
+		(x).tv_usec += (y).tv_usec - (z).tv_usec; \
+		/* Normalize after each add to avoid overflow/underflow of tv_usec */ \
+		while ((x).tv_usec < 0) \
+		{ \
+			(x).tv_usec += 1000000; \
+			(x).tv_sec--; \
+		} \
+		while ((x).tv_usec >= 1000000) \
+		{ \
+			(x).tv_usec -= 1000000; \
+			(x).tv_sec++; \
+		} \
+	} while (0)
+
+#define INSTR_TIME_GET_DOUBLE(t) \
+	(((double) (t).tv_sec) + ((double) (t).tv_usec) / 1000000.0)
+
+#define INSTR_TIME_GET_MILLISEC(t) \
+	(((double) (t).tv_sec * 1000.0) + ((double) (t).tv_usec) / 1000.0)
+
+#define INSTR_TIME_GET_MICROSEC(t) \
+	(((uint64) (t).tv_sec * (uint64) 1000000) + (uint64) (t).tv_usec)
+
+#else	/* WIN32 */
+
+typedef LARGE_INTEGER instr_time;
+
+#define INSTR_TIME_IS_ZERO(t)	((t).QuadPart == 0)
+
+#define INSTR_TIME_SET_ZERO(t)	((t).QuadPart = 0)
+
+#define INSTR_TIME_SET_CURRENT(t)	QueryPerformanceCounter(&(t))
+
+#define INSTR_TIME_SUBTRACT(x,y) \
+	((x).QuadPart -= (y).QuadPart)
+
+#define INSTR_TIME_ACCUM_DIFF(x,y,z) \
+	((x).QuadPart += (y).QuadPart - (z).QuadPart)
+
+#define INSTR_TIME_GET_DOUBLE(t) \
+	(((double) (t).QuadPart) / GetTimerFrequency())
+
+#define INSTR_TIME_GET_MILLISEC(t) \
+	(((double) (t).QuadPart * 1000.0) / GetTimerFrequency())
+
+#define INSTR_TIME_GET_MICROSEC(t) \
+	((uint64) (((double) (t).QuadPart * 1000000.0) / GetTimerFrequency()))
+
+static __inline__ double
+GetTimerFrequency(void)
+{
+	LARGE_INTEGER f;
+
+	QueryPerformanceFrequency(&f);
+	return (double) f.QuadPart;
+}
+
+#endif   /* WIN32 */
+
+#endif   /* INSTR_TIME_H */