[PATCH] replace fgets() with mmap() and introduce udev_lib.[hc]

Here we replace the various fgets() with a mmap() call for the config
file reading, due to the reported performance problems with klibc.

Thanks to Patrick's testing, it makes a very small, close to nothing
speed gain for libc users, but a 6 times speed increase for klibc users
with a 1000 line config file.

I've created a udev_lib.[hc] for this and also moved all the generic
stuff from udev.h in there and uninlined the functions.

1 files changed, 111 insertions, 0 deletions

diff --git a/udev_lib.c b/udev_lib.c
new file mode 100644
index 0000000000..50598a4a31
--- /dev/null
+++ b/udev_lib.c
@@ -0,0 +1,111 @@
+/*
+ * udev_lib - generic stuff used by udev
+ *
+ * Copyright (C) 2004 Kay Sievers <kay@vrfy.org>
+ *
+ *	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 version 2 of the License.
+ * 
+ *	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.,
+ *	675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+
+#include "libsysfs/sysfs/libsysfs.h"
+#include "udev.h"
+#include "udev_lib.h"
+
+
+char *get_action(void)
+{
+	char *action;
+
+	action = getenv("ACTION");
+	if (action != NULL && strlen(action) > ACTION_SIZE)
+		action[ACTION_SIZE-1] = '\0';
+
+	return action;
+}
+
+char *get_devpath(void)
+{
+	char *devpath;
+
+	devpath = getenv("DEVPATH");
+	if (devpath != NULL && strlen(devpath) > DEVPATH_SIZE)
+		devpath[DEVPATH_SIZE-1] = '\0';
+
+	return devpath;
+}
+
+char *get_seqnum(void)
+{
+	char *seqnum;
+
+	seqnum = getenv("SEQNUM");
+
+	return seqnum;
+}
+
+char *get_subsystem(char *subsystem)
+{
+	if (subsystem != NULL && strlen(subsystem) > SUBSYSTEM_SIZE)
+		subsystem[SUBSYSTEM_SIZE-1] = '\0';
+
+	return subsystem;
+}
+
+int file_map(const char *filename, char **buf, size_t *bufsize)
+{
+	struct stat stats;
+	int fd;
+
+	fd = open(filename, O_RDONLY);
+	if (fd < 0) {
+		return -1;
+	}
+
+	if (fstat(fd, &stats) < 0) {
+		return -1;
+	}
+
+	*buf = mmap(NULL, stats.st_size, PROT_READ, MAP_SHARED, fd, 0);
+	if (*buf == MAP_FAILED) {
+		return -1;
+	}
+	*bufsize = stats.st_size;
+
+	close(fd);
+
+	return 0;
+}
+
+void file_unmap(char *buf, size_t bufsize)
+{
+	munmap(buf, bufsize);
+}
+
+size_t buf_get_line(char *buf, size_t buflen, size_t cur)
+{
+	size_t count = 0;
+
+	for (count = cur; count < buflen && buf[count] != '\n'; count++);
+
+	return count - cur;
+}
+