r4709 - in trunk/src/target: . input-filter

[laforge at docs.openmoko.org]

Author: laforge
Date: 2008-10-10 01:16:20 +0200 (Fri, 10 Oct 2008)
New Revision: 4709

Added:
   trunk/src/target/input-filter/
   trunk/src/target/input-filter/input-filter.c
Log:
Add a small (written in C) helper program that filters /dev/input/event
file and removes all ABS and REL type events from the event stream.

This is to be used as a quick fix to solve performance problems with
current FSO related to FSO processing each and every individual ABS_X/ABS_Y
event from s3c2410_ts


Added: trunk/src/target/input-filter/input-filter.c
===================================================================
--- trunk/src/target/input-filter/input-filter.c	                        (rev 0)
+++ trunk/src/target/input-filter/input-filter.c	2008-10-09 23:16:20 UTC (rev 4709)
@@ -0,0 +1,188 @@
+/* /dev/input/event filtering tool
+ *
+ * (C) 2008 by Harald Welte <laforge at openmoko.org>
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */ 
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/fcntl.h>
+
+#include <linux/input.h>
+
+#define READBUF_SIZE (1024*sizeof(struct input_event))
+
+struct stats {
+	unsigned int num_reads;
+	unsigned int num_events_in;
+	unsigned int num_events_out;
+	struct timeval tv_first;
+	struct timeval tv_last;
+};
+
+static struct stats st;
+static char *indev_filename;
+static char *out_filename;
+static int outfd;
+
+static int handle_event(struct input_event *evt)
+{
+	int rc;
+
+	/* statistics */
+	st.num_events_in++;
+	if (st.num_events_in == 1)
+		memcpy(&st.tv_first, &evt->time, sizeof(st.tv_first));
+	memcpy(&st.tv_last, &evt->time, sizeof(st.tv_last));
+
+	switch (evt->type) {
+		/* supress any absolute or relative movement events */
+		case EV_ABS:
+		case EV_REL:
+			return sizeof(*evt);
+		default:
+			break;
+	}
+
+	rc = write(outfd, evt, sizeof(*evt));
+	st.num_events_out++;
+
+	return rc;
+}
+
+static void time_difference(const struct timeval *start,
+			    struct timeval *end,
+			    struct timeval *result)
+{
+	if (end->tv_usec < start->tv_usec) {
+		end->tv_usec += 1000000;
+		end->tv_sec -= 1;
+	}
+
+	result->tv_usec = end->tv_usec - start->tv_usec;
+	result->tv_sec = end->tv_sec - start->tv_sec;
+}
+
+static void reset_stats(void)
+{
+	memset(&st, 0, sizeof(st));
+}
+
+static void print_stats(void)
+{
+	struct timeval tv;
+
+	time_difference(&st.tv_first, &st.tv_last, &tv);
+
+	printf("input statiststics for device %s:\n", indev_filename);
+	printf("\t%u reads, %u events in, %u events out, %u.%u seconds\n",
+		st.num_reads, st.num_events_in, st.num_events_out,
+		tv.tv_sec, tv.tv_usec);
+	printf("\t%u events/read, %u events/second in, %u events/secound out\n",
+		st.num_events_in / st.num_reads,
+		st.num_events_in / tv.tv_sec, st.num_events_out / tv.tv_sec);
+}
+
+void sighand(int signal)
+{
+	fprintf(stderr, "received signal %d\n", signal);
+	print_stats();
+
+	switch (signal) {
+	case SIGHUP:
+		break;
+	case SIGUSR1:
+		reset_stats();
+	case SIGINT:
+	case SIGTERM:
+		exit(0);
+		break;
+	}
+}
+
+int main(int argc, char **argv)
+{
+	int infd;
+	char buf[READBUF_SIZE];
+
+	if (argc != 3) {
+		fprintf(stderr, "this program needs two single arguments: "
+			"the /dev/input/eventX device you want to open, "
+			"and the name of the FIFO to be used for output\n");
+		exit(2);
+	}
+
+	indev_filename = argv[1];
+	out_filename = argv[2];
+
+	infd = open(indev_filename, O_RDONLY);
+	if (infd < 0) {
+		perror("open input");
+		exit(1);
+	}
+
+	outfd = open(out_filename, O_WRONLY);
+	if (outfd < 0) {
+		perror("open output");
+		close (infd);
+		exit(1);
+	}
+
+	signal(SIGHUP, &sighand);
+	signal(SIGINT, &sighand);
+	signal(SIGTERM, &sighand);
+	signal(SIGUSR1, &sighand);
+	signal(SIGPIPE, SIG_IGN);
+
+	while (1) {
+		int rc, i;
+		struct input_event *evt;
+
+		rc = read(infd, buf, sizeof(buf));
+		if (rc < 0) {
+			perror("read");
+			break;
+		}
+		st.num_reads++;
+
+		for (i = 0; i < rc; i += sizeof(struct input_event)) {
+			evt = (struct input_event *) (buf + i);
+			rc = handle_event(evt);
+			if (rc < 0) {
+				perror("handle_event");
+				exit(3);
+			}
+			if (rc < sizeof(struct input_event)) {
+				fprintf(stderr, "short write\n");
+				close(outfd);
+				/* we do a blocking reopen */
+				outfd = open(out_filename, O_WRONLY);
+				if (outfd < 0) {
+					perror("reopen output");
+					close (infd);
+					exit(4);
+				}
+			}
+		}
+	}
+}