From: kay.sievers@vrfy.org <kay.sievers@vrfy.org>
Date: Tue, 23 Mar 2004 06:22:20 +0000 (-0800)
Subject: [PATCH] replace fgets() with mmap() and introduce udev_lib.[hc]
X-Git-Tag: 023~32
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=c81b35c08bbd7789883993ea280e0d3772cce440

[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.
---

diff --git a/Makefile b/Makefile
index 000918573..0604c1fa0 100644
--- a/Makefile
+++ b/Makefile
@@ -201,7 +201,8 @@ SYSFS =	$(PWD)/libsysfs/sysfs_bus.o	\
 	$(PWD)/libsysfs/sysfs_utils.o	\
 	$(PWD)/libsysfs/dlist.o
 
-OBJS =	udev_config.o	\
+OBJS =	udev_lib.o	\
+	udev_config.o	\
 	udev-add.o	\
 	udev-remove.o	\
 	udevdb.o	\
@@ -211,6 +212,7 @@ OBJS =	udev_config.o	\
 	$(TDB)
 
 HEADERS =	udev.h		\
+		udev_lib.h	\
 		namedev.h	\
 		udev_version.h	\
 		udev_dbus.h	\
@@ -279,7 +281,7 @@ $(TESTER): $(TESTER).o $(OBJS) $(HEADERS) $(LIBC)
 	$(STRIPCMD) $@
 
 $(INFO): $(INFO).o $(OBJS) $(HEADERS) $(LIBC)
-	$(LD) $(LDFLAGS) -o $@ $(CRT0) udevinfo.o udev_config.o udevdb.o $(SYSFS) $(TDB) $(LIB_OBJS) $(ARCH_LIB_OBJS)
+	$(LD) $(LDFLAGS) -o $@ $(CRT0) udevinfo.o udev_lib.o udev_config.o udevdb.o $(SYSFS) $(TDB) $(LIB_OBJS) $(ARCH_LIB_OBJS)
 	$(STRIPCMD) $@
 
 $(DAEMON): $(DAEMON).o udevd.h $(LIBC)
@@ -287,7 +289,7 @@ $(DAEMON): $(DAEMON).o udevd.h $(LIBC)
 	$(STRIPCMD) $@
 
 $(SENDER): $(SENDER).o udevd.h $(LIBC)
-	$(LD) $(LDFLAGS) -o $@ $(CRT0) udevsend.o $(LIB_OBJS) $(ARCH_LIB_OBJS)
+	$(LD) $(LDFLAGS) -o $@ $(CRT0) udevsend.o udev_lib.o $(LIB_OBJS) $(ARCH_LIB_OBJS)
 	$(STRIPCMD) $@
 
 $(STARTER): $(STARTER).o $(HEADERS) $(LIBC)
diff --git a/klibc_fixups.c b/klibc_fixups.c
index 99460c32f..eaa240c18 100644
--- a/klibc_fixups.c
+++ b/klibc_fixups.c
@@ -28,6 +28,7 @@
 #include <fcntl.h>
 #include <sys/types.h>
 
+#include "udev.h"
 #include "klibc_fixups.h"
 #include "logging.h"
 
@@ -40,22 +41,35 @@
 static unsigned long get_id_by_name(const char *uname, const char *dbfile)
 {
 	unsigned long id = -1;
-	FILE *file;
-	char buf[255];
+	char line[255];
+	char *buf;
+	size_t bufsize;
+	size_t cur;
+	size_t count;
 	char *pos;
 	char *name;
 	char *idstr;
 	char *tail;
 
-	file = fopen(dbfile, "r");
-	if (file == NULL) {
-		dbg("unable to open file '%s'", dbfile);
+	if (file_map(dbfile, &buf, &bufsize) == 0) {
+		dbg("reading '%s' as db file", dbfile);
+	} else {
+		dbg("can't open '%s' as db file", dbfile);
 		return -1;
 	}
 
+	/* loop through the whole file */
+
+	cur = 0;
 	while (1) {
-		pos = fgets(buf, sizeof(buf), file);
-		if (pos == NULL)
+		count = buf_get_line(buf, bufsize, cur);
+
+		strncpy(line, buf + cur, count);
+		line[count] = '\0';
+		pos = line;
+
+		cur += count+1;
+		if (cur > bufsize)
 			break;
 
 		/* get name */
@@ -82,7 +96,7 @@ static unsigned long get_id_by_name(const char *uname, const char *dbfile)
 		}
 	}
 
-	fclose(file);
+	file_unmap(buf, bufsize);
 	return id;
 }
 
diff --git a/namedev.c b/namedev.c
index 025a14aea..8f781a66e 100644
--- a/namedev.c
+++ b/namedev.c
@@ -36,6 +36,7 @@
 #include "libsysfs/sysfs/libsysfs.h"
 #include "list.h"
 #include "udev.h"
+#include "udev_lib.h"
 #include "udev_version.h"
 #include "logging.h"
 #include "namedev.h"
diff --git a/namedev_parse.c b/namedev_parse.c
index 8198f7e68..f4ffdb21d 100644
--- a/namedev_parse.c
+++ b/namedev_parse.c
@@ -30,7 +30,6 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
-#include <fcntl.h>
 #include <ctype.h>
 #include <unistd.h>
 #include <sys/stat.h>
@@ -38,6 +37,7 @@
 #include <errno.h>
 
 #include "udev.h"
+#include "udev_lib.h"
 #include "logging.h"
 #include "namedev.h"
 
@@ -153,27 +153,36 @@ static int namedev_parse_rules(char *filename)
 	char *temp2;
 	char *temp3;
 	char *attr;
-	FILE *fd;
+	char *buf;
+	size_t bufsize;
+	size_t cur;
+	size_t count;
 	int program_given = 0;
 	int retval = 0;
 	struct config_device dev;
 
-	fd = fopen(filename, "r");
-	if (fd != NULL) {
+	if (file_map(filename, &buf, &bufsize) == 0) {
 		dbg("reading '%s' as rules file", filename);
 	} else {
-		dbg("can't open '%s' as a rules file", filename);
-		return -ENODEV;
+		dbg("can't open '%s' as rules file", filename);
+		return -1;
 	}
 
 	/* loop through the whole file */
+	cur = 0;
 	lineno = 0;
 	while (1) {
-		/* get a line */
-		temp = fgets(line, sizeof(line), fd);
-		if (temp == NULL)
-			goto exit;
+		count = buf_get_line(buf, bufsize, cur);
+
+		strncpy(line, buf + cur, count);
+		line[count] = '\0';
+		temp = line;
 		lineno++;
+
+		cur += count+1;
+		if (cur > bufsize)
+			break;
+
 		dbg_parse("read '%s'", temp);
 
 		/* eat the whitespace */
@@ -311,8 +320,8 @@ error:
 			    filename, lineno, temp - line);
 		}
 	}
-exit:
-	fclose(fd);
+
+	file_unmap(buf, bufsize);
 	return retval;
 }
 
@@ -321,22 +330,31 @@ static int namedev_parse_permissions(char *filename)
 	char line[255];
 	char *temp;
 	char *temp2;
-	FILE *fd;
+	char *buf;
+	size_t bufsize;
+	size_t cur;
+	size_t count;
 	int retval = 0;
 	struct perm_device dev;
 
-	fd = fopen(filename, "r");
-	if (fd != NULL) {
+	if (file_map(filename, &buf, &bufsize) == 0) {
 		dbg("reading '%s' as permissions file", filename);
 	} else {
 		dbg("can't open '%s' as permissions file", filename);
-		return -ENODEV;
+		return -1;
 	}
 
 	/* loop through the whole file */
+	cur = 0;
 	while (1) {
-		temp = fgets(line, sizeof(line), fd);
-		if (temp == NULL)
+		count = buf_get_line(buf, bufsize, cur);
+
+		strncpy(line, buf + cur, count);
+		line[count] = '\0';
+		temp = line;
+
+		cur += count+1;
+		if (cur > bufsize)
 			break;
 
 		dbg_parse("read '%s'", temp);
@@ -394,7 +412,7 @@ static int namedev_parse_permissions(char *filename)
 	}
 
 exit:
-	fclose(fd);
+	file_unmap(buf, bufsize);
 	return retval;
 }
 
diff --git a/udev-add.c b/udev-add.c
index ce723e45c..2bd16014f 100644
--- a/udev-add.c
+++ b/udev-add.c
@@ -37,6 +37,7 @@
 
 #include "libsysfs/sysfs/libsysfs.h"
 #include "udev.h"
+#include "udev_lib.h"
 #include "udev_version.h"
 #include "udev_dbus.h"
 #include "udev_selinux.h"
diff --git a/udev-remove.c b/udev-remove.c
index 44ad603d4..d90971345 100644
--- a/udev-remove.c
+++ b/udev-remove.c
@@ -29,6 +29,7 @@
 #include <errno.h>
 
 #include "udev.h"
+#include "udev_lib.h"
 #include "udev_version.h"
 #include "udev_dbus.h"
 #include "logging.h"
diff --git a/udev.c b/udev.c
index 9b4d91f75..d10badc8e 100644
--- a/udev.c
+++ b/udev.c
@@ -20,15 +20,17 @@
  *
  */
 
+#include <stdio.h>
+#include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
-#include <stdio.h>
-#include <errno.h>
 #include <ctype.h>
+#include <errno.h>
 #include <signal.h>
 
 #include "libsysfs/sysfs/libsysfs.h"
 #include "udev.h"
+#include "udev_lib.h"
 #include "udev_version.h"
 #include "udev_dbus.h"
 #include "logging.h"
diff --git a/udev.h b/udev.h
index 8752f595d..54269dfd3 100644
--- a/udev.h
+++ b/udev.h
@@ -20,25 +20,22 @@
  *
  */
 
-#ifndef UDEV_H
-#define UDEV_H
+#ifndef _UDEV_H_
+#define _UDEV_H_
 
-#include <stdlib.h>
-#include <string.h>
-#include <sysfs/libsysfs.h>
-#include <stddef.h>
 #include <sys/param.h>
+#include "libsysfs/sysfs/libsysfs.h"
 
 #define COMMENT_CHARACTER		'#'
 
-#define NAME_SIZE	100
-#define OWNER_SIZE	30
-#define GROUP_SIZE	30
-#define MODE_SIZE	8
+#define NAME_SIZE			100
+#define OWNER_SIZE			30
+#define GROUP_SIZE			30
+#define MODE_SIZE			8
 
-#define ACTION_SIZE	30
-#define DEVPATH_SIZE	255
-#define SUBSYSTEM_SIZE	30
+#define ACTION_SIZE			30
+#define DEVPATH_SIZE			255
+#define SUBSYSTEM_SIZE			30
 
 /* length of public data */
 #define UDEVICE_LEN (offsetof(struct udevice, bus_id))
@@ -61,87 +58,6 @@ struct udevice {
 	char kernel_name[NAME_SIZE];
 };
 
-#define strfieldcpy(to, from) \
-do { \
-	to[sizeof(to)-1] = '\0'; \
-	strncpy(to, from, sizeof(to)-1); \
-} while (0)
-
-#define strfieldcat(to, from) \
-do { \
-	to[sizeof(to)-1] = '\0'; \
-	strncat(to, from, sizeof(to) - strlen(to)-1); \
-} while (0)
-
-#define strfieldcpymax(to, from, maxsize) \
-do { \
-	to[maxsize-1] = '\0'; \
-	strncpy(to, from, maxsize-1); \
-} while (0)
-
-#define strfieldcatmax(to, from, maxsize) \
-do { \
-	to[maxsize-1] = '\0'; \
-	strncat(to, from, maxsize - strlen(to)-1); \
-} while (0)
-
-#define strintcat(to, i) \
-do { \
-	to[sizeof(to)-1] = '\0'; \
-	snprintf((to) + strlen(to), sizeof(to) - strlen(to)-1, "%u", i); \
-} while (0)
-
-#define strintcatmax(to, i, maxsize) \
-do { \
-	to[maxsize-1] = '\0'; \
-	snprintf((to) + strlen(to), maxsize - strlen(to)-1, "%u", i); \
-} while (0)
-
-#define foreach_strpart(str, separator, pos, len) \
-	for(pos = str, len = 0; \
-	    (pos) < ((str) + strlen(str)); \
-	    pos = pos + len + strspn(pos, separator), len = strcspn(pos, separator)) \
-		if (len > 0)
-
-static inline char *get_action(void)
-{
-	char *action;
-
-	action = getenv("ACTION");
-	if (action != NULL && strlen(action) > ACTION_SIZE)
-		action[ACTION_SIZE-1] = '\0';
-
-	return action;
-}
-
-static inline char *get_devpath(void)
-{
-	char *devpath;
-
-	devpath = getenv("DEVPATH");
-	if (devpath != NULL && strlen(devpath) > DEVPATH_SIZE)
-		devpath[DEVPATH_SIZE-1] = '\0';
-
-	return devpath;
-}
-
-static inline char *get_seqnum(void)
-{
-	char *seqnum;
-
-	seqnum = getenv("SEQNUM");
-
-	return seqnum;
-}
-
-static inline char *get_subsystem(char *subsystem)
-{
-	if (subsystem != NULL && strlen(subsystem) > SUBSYSTEM_SIZE)
-		subsystem[SUBSYSTEM_SIZE-1] = '\0';
-
-	return subsystem;
-}
-
 extern int udev_add_device(char *path, char *subsystem, int fake);
 extern int udev_remove_device(char *path, char *subsystem);
 extern void udev_init_config(void);
diff --git a/udev_config.c b/udev_config.c
index e2031dc64..57a512d71 100644
--- a/udev_config.c
+++ b/udev_config.c
@@ -34,6 +34,7 @@
 
 #include "libsysfs/sysfs/libsysfs.h"
 #include "udev.h"
+#include "udev_lib.h"
 #include "udev_version.h"
 #include "logging.h"
 #include "namedev.h"
@@ -131,12 +132,14 @@ static int parse_config_file(void)
 	char *temp;
 	char *variable;
 	char *value;
-	FILE *fd;
-	int lineno = 0;
+	char *buf;
+	size_t bufsize;
+	size_t cur;
+	size_t count;
+	int lineno;
 	int retval = 0;
-	
-	fd = fopen(udev_config_filename, "r");
-	if (fd != NULL) {
+
+	if (file_map(udev_config_filename, &buf, &bufsize) == 0) {
 		dbg("reading '%s' as config file", udev_config_filename);
 	} else {
 		dbg("can't open '%s' as config file", udev_config_filename);
@@ -144,13 +147,20 @@ static int parse_config_file(void)
 	}
 
 	/* loop through the whole file */
+	lineno = 0;
+	cur = 0;
 	while (1) {
-		/* get a line */
-		temp = fgets(line, sizeof(line), fd);
-		if (temp == NULL)
-			goto exit;
+		count = buf_get_line(buf, bufsize, cur);
+
+		strncpy(line, buf + cur, count);
+		line[count] = '\0';
+		temp = line;
 		lineno++;
 
+		cur += count+1;
+		if (cur > bufsize)
+			break;
+
 		dbg_parse("read '%s'", temp);
 
 		/* eat the whitespace at the beginning of the line */
@@ -182,8 +192,8 @@ static int parse_config_file(void)
 	}
 	dbg_parse("%s:%d:%Zd: error parsing '%s'", udev_config_filename,
 		  lineno, temp - line, temp);
-exit:
-	fclose(fd);
+
+	file_unmap(buf, bufsize);
 	return retval;
 }
 
diff --git a/udev_lib.c b/udev_lib.c
new file mode 100644
index 000000000..50598a4a3
--- /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;
+}
+
diff --git a/udev_lib.h b/udev_lib.h
new file mode 100644
index 000000000..565d87e9a
--- /dev/null
+++ b/udev_lib.h
@@ -0,0 +1,78 @@
+/*
+ * udev_lib - generic stuff used by udev
+ *
+ * Copyright (C) 2004 Kay Sievers <kay.sievers@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.
+ *
+ */
+
+#ifndef _UDEV_LIB_H_
+#define _UDEV_LIB_H_
+
+
+#define strfieldcpy(to, from) \
+do { \
+	to[sizeof(to)-1] = '\0'; \
+	strncpy(to, from, sizeof(to)-1); \
+} while (0)
+
+#define strfieldcat(to, from) \
+do { \
+	to[sizeof(to)-1] = '\0'; \
+	strncat(to, from, sizeof(to) - strlen(to)-1); \
+} while (0)
+
+#define strfieldcpymax(to, from, maxsize) \
+do { \
+	to[maxsize-1] = '\0'; \
+	strncpy(to, from, maxsize-1); \
+} while (0)
+
+#define strfieldcatmax(to, from, maxsize) \
+do { \
+	to[maxsize-1] = '\0'; \
+	strncat(to, from, maxsize - strlen(to)-1); \
+} while (0)
+
+#define strintcat(to, i) \
+do { \
+	to[sizeof(to)-1] = '\0'; \
+	snprintf((to) + strlen(to), sizeof(to) - strlen(to)-1, "%u", i); \
+} while (0)
+
+#define strintcatmax(to, i, maxsize) \
+do { \
+	to[maxsize-1] = '\0'; \
+	snprintf((to) + strlen(to), maxsize - strlen(to)-1, "%u", i); \
+} while (0)
+
+#define foreach_strpart(str, separator, pos, len) \
+	for(pos = str, len = 0; \
+	    (pos) < ((str) + strlen(str)); \
+	    pos = pos + len + strspn(pos, separator), len = strcspn(pos, separator)) \
+		if (len > 0)
+
+
+extern char *get_action(void);
+extern char *get_devpath(void);
+extern char *get_seqnum(void);
+extern char *get_subsystem(char *subsystem);
+extern int file_map(const char *filename, char **buf, size_t *bufsize);
+extern void file_unmap(char *buf, size_t bufsize);
+extern size_t buf_get_line(char *buf, size_t buflen, size_t cur);
+
+
+#endif
diff --git a/udevd.c b/udevd.c
index efcb65bb5..4cb3e1d40 100644
--- a/udevd.c
+++ b/udevd.c
@@ -36,6 +36,7 @@
 
 #include "list.h"
 #include "udev.h"
+#include "udev_lib.h"
 #include "udev_version.h"
 #include "udevd.h"
 #include "logging.h"
diff --git a/udevdb.c b/udevdb.c
index 01df3ba7e..40580e5a3 100644
--- a/udevdb.c
+++ b/udevdb.c
@@ -1,5 +1,5 @@
 /*
- * udevdb.c
+ * udevdb.c - udev database library
  *
  * Userspace devfs
  *
@@ -21,13 +21,11 @@
  *
  */
 
-/*
- * udev database library
- */
 #define _KLIBC_HAS_ARCH_SIG_ATOMIC_T
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <stddef.h>
 #include <fcntl.h>
 #include <string.h>
 #include <sys/stat.h>
@@ -35,8 +33,9 @@
 #include <signal.h>
 
 #include "libsysfs/sysfs/libsysfs.h"
-#include "udev_version.h"
 #include "udev.h"
+#include "udev_lib.h"
+#include "udev_version.h"
 #include "logging.h"
 #include "namedev.h"
 #include "udevdb.h"
diff --git a/udevinfo.c b/udevinfo.c
index ffc5e31f0..5ad9e6474 100644
--- a/udevinfo.c
+++ b/udevinfo.c
@@ -30,6 +30,7 @@
 #include "libsysfs/sysfs/libsysfs.h"
 #include "libsysfs/dlist.h"
 #include "udev.h"
+#include "udev_lib.h"
 #include "udev_version.h"
 #include "logging.h"
 #include "udevdb.h"
diff --git a/udevsend.c b/udevsend.c
index 11234808d..f1c46d336 100644
--- a/udevsend.c
+++ b/udevsend.c
@@ -36,6 +36,7 @@
 #include <linux/stddef.h>
 
 #include "udev.h"
+#include "udev_lib.h"
 #include "udev_version.h"
 #include "udevd.h"
 #include "logging.h"