Syslinux - Mar 2010 - [MODULE] COM32 module to time null-dumping a file

From: Gene Cumm <gene.cumm at gmail.com>

COM32/samples/cptime.c: A module for coarse null-dumping speed
comparisons.  Accepts multiple files and an option of -s (as the first
option) to provide a simple output.  Also computes/displays +/- 1 tick
to show coarseness.

Signed-off-by: Gene Cumm <gene.cumm at gmail.com>

---

I'd recommend using a file that takes around 100 ticks to get a
reasonable idea but you'd probably need closer to 1000+ if you want
more precise numbers.

I haven't checked that this is OK against scripts/checkpatch.pl as I'm
having difficulty running it (been around a year since I last used it)
but things should be pretty close.  Long term, I should break it out
to also having a .h to clean up the #ifdef.  I also need to go back
and review the indentation styling per current standards.

I designed this (as I've done before) to compile for both Linux and
Syslinux COM32 with very similar functionality.

I've tested different sizes for the buffer/fetch block but haven't
determined the "optimal" size yet (which might vary by environment...
I'm not sure.).



diff --git a/com32/samples/cptime.c b/com32/samples/cptime.c
new file mode 100644
index 0000000..73266ec
--- /dev/null
+++ b/com32/samples/cptime.c
@@ -0,0 +1,138 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 2010 Gene Cumm - All Rights Reserved
+ *
+ *   This program 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, Inc., 53 Temple Place Ste 330,
+ *   Boston MA 02111-1307, USA; either version 2 of the License, or
+ *   (at your option) any later version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * cptime.c
+ *
+ * Timed copy; read entire file then output total time, bytes transferred,
+ * and compute transfer rate.
+ *
+ * cptime [-s] _FILE_....
+ *	-s	Change to simple output mode without computing transfer rate
+ *	_FILE_.....	Space delimited list of files to dump
+ */
+
+/*
+ * ToDos:
+ * Refine timing to be more precise.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/times.h>
+#include <consoles.h>
+#include <minmax.h>
+
+
+#ifdef __COM32__
+#define BUFSZ	2048
+/* What's optimal?  Under 4k?
+ *	layout.inc: xfer_buf_seg	equ 1000h
+ */
+
+float get_tps(){	return 18.2;	}
+
+#else /* __COM32__ */
+
+#define BUFSZ 16384
+/* Need to check what might be a "best" buffer/fetch block size here
*/
+
+float get_tps(){	return (float)sysconf(_SC_CLK_TCK);	}
+void print_cp_result2(char *fn, int bcnt, clock_t bc, clock_t ec)
+{
+	float et, dr;
+	et = ((float)(ec - bc)) / (float)sysconf(_SC_CLK_TCK);
+	dr = ((float)bcnt) / et;
+	printf("  %dB in %.3fs from '%s'\n", bcnt, et, fn);
+	printf("  %.0f B/s; %.0f KiB/s; %.0f MiB/s\n", dr, dr/1024,
dr/1048576);
+}	/* void print_cp_result2(char *fn, int bcnt, clock_t bc, clock_t ec) */
+#endif /* __COM32__ */
+
+void print_cp_result_tick(int bcnt, clock_t et, float tps, int offs)
+{
+	int dr;
+	dr = bcnt * tps / max(1,(et + offs));	// prevent divide by 0
+	printf("  %+d %d B/s; %d KiB/s; %d MiB/s\n", offs, dr, dr/1024,
dr/1048576);
+}	/* void print_cp_result_tick(int bcnt, clock_t et, float tps, int offs) */
+
+void print_cp_result(char *fn, int bcnt, clock_t bc, clock_t ec)
+{
+	float tps;
+	tps = get_tps();
+	printf("  %dB in %d ticks from '%s'\n", bcnt, (int)(ec -
bc), fn);
+	printf("  ~%d ticks per second; %d\n", (int)tps, (BUFSZ));
+	print_cp_result_tick(bcnt, (ec - bc), tps, 0);
+	print_cp_result_tick(bcnt, (ec - bc), tps, 1);
+	print_cp_result_tick(bcnt, (ec - bc), tps, -1);
+}	/* void print_cp_result(char *fn, int bcnt, clock_t bc, clock_t ec) */
+
+void print_cp_result_simple(char *fn, int bcnt, clock_t bc, clock_t ec)
+{
+	printf("  %dB  %dt %dx '%s'\n", bcnt, (int)(ec - bc),
(BUFSZ), fn);
+}	/* void print_cp_result_simple(char *fn, int bcnt, clock_t bc, clock_t ec) */
+
+int time_copy(char *fn, char do_simple)
+{
+	int fd, rv = 0;
+	int bcnt;
+	int numrd;
+	struct tms tm;
+	clock_t bc, ec;
+	char buf[BUFSZ + 1];
+	buf[0] = 0;
+	fd = open(fn, O_RDONLY);
+	if (fd == -1) {
+		switch (errno){
+			case ENOENT :
+				printf("File '%s' does not exist\n", fn);
+				break;
+			default :
+				printf("Error '%d' opening file '%s'\n", errno,
fn);
+		}
+		rv = 1;
+	} else {
+		bc = times(&tm);
+		numrd = read(fd, buf, BUFSZ);
+		bcnt = numrd;
+		while(numrd > 0){
+			numrd = read(fd, buf, BUFSZ);
+			bcnt = bcnt + numrd;
+		}
+		ec = times(&tm);
+		close(fd);
+		if (do_simple)
+			print_cp_result_simple(fn, bcnt, bc, ec);
+		else
+			print_cp_result(fn, bcnt, bc, ec);
+	}
+	return rv;
+}	/* int time_copy(char *fn, char do_simple) */
+
+int main(int argc, char *argv[])
+{
+	int i, st_arg = 1;
+	char do_simple = 0;
+	console_ansi_std();
+	if (argc == 1)
+		printf("%s: Please specify a file\n", argv[0]);
+	if ((argc > 2) && (argv[1][0] == '-') &&
(argv[1][1] == 's') &
(argv[1][2] == 0) )
+	{
+		do_simple = 1;
+		st_arg = 2;
+	}
+	for (i=st_arg;i<argc;i++)
+		time_copy(argv[i], do_simple);
+	return 0;
+}	/* int main(int argc, char *argv[]) */