Use access() instead of stat() when possible

We were using the stat() system call in quite a few places when we didn't
actually need anything the stat struct returned- we were simply checking for
file existence. access() will be more efficient in those cases.

Before (strace pacman -Ss pacman):
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 33.16    0.005987           0     19016           stat64

After:
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 34.85    0.003863           0     12633         1 access
  7.95    0.000881           0      6391         7 stat64

Signed-off-by: Dan McGee <dan@archlinux.org>

3 files changed, 7 insertions, 12 deletions

diff --git a/src/pacman/package.c b/src/pacman/package.c
index 1698806f..06800378 100644
--- a/src/pacman/package.c
+++ b/src/pacman/package.c
@@ -22,8 +22,8 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <unistd.h>
 #include <limits.h>
-#include <sys/stat.h>
 #include <wchar.h>
 
 #include <alpm.h>
@@ -176,7 +176,6 @@ void dump_pkg_backups(pmpkg_t *pkg)
 	if(alpm_pkg_get_backup(pkg)) {
 		/* package has backup files, so print them */
 		for(i = alpm_pkg_get_backup(pkg); i; i = alpm_list_next(i)) {
-			struct stat buf;
 			char path[PATH_MAX];
 			char *str = strdup(alpm_list_getdata(i));
 			char *ptr = index(str, '\t');
@@ -188,7 +187,7 @@ void dump_pkg_backups(pmpkg_t *pkg)
 			ptr++;
 			snprintf(path, PATH_MAX-1, "%s%s", root, str);
 			/* if we find the file, calculate checksums, otherwise it is missing */
-			if(!stat(path, &buf)) {
+			if(access(path, R_OK) == 0) {
 				char *md5sum = alpm_get_md5sum(path);
 
 				if(md5sum == NULL) {
diff --git a/src/pacman/util.c b/src/pacman/util.c
index e702886b..d7ac9e38 100644
--- a/src/pacman/util.c
+++ b/src/pacman/util.c
@@ -22,7 +22,6 @@
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <sys/time.h>
-#include <sys/stat.h>
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -125,7 +124,7 @@ int makepath(const char *path)
 	 * orig - a copy of path so we can safely butcher it with strsep
 	 * str - the current position in the path string (after the delimiter)
 	 * ptr - the original position of str after calling strsep
-	 * incr - incrementally generated path for use in stat/mkdir call
+	 * incr - incrementally generated path for use in access/mkdir call
 	 */
 	char *orig, *str, *ptr, *incr;
 	mode_t oldmask = umask(0000);
@@ -136,12 +135,11 @@ int makepath(const char *path)
 	str = orig;
 	while((ptr = strsep(&str, "/"))) {
 		if(strlen(ptr)) {
-			struct stat buf;
 			/* we have another path component- append the newest component to
 			 * existing string and create one more level of dir structure */
 			strcat(incr, "/");
 			strcat(incr, ptr);
-			if(stat(incr, &buf)) {
+			if(access(incr, F_OK)) {
 				if(mkdir(incr, 0755)) {
 					ret = 1;
 					break;
diff --git a/src/util/testdb.c b/src/util/testdb.c
index f354ecab..87bfcf96 100644
--- a/src/util/testdb.c
+++ b/src/util/testdb.c
@@ -23,7 +23,6 @@
 #include <errno.h>
 #include <limits.h>
 #include <string.h>
-#include <sys/stat.h>
 #include <dirent.h>
 #include <libgen.h>
 
@@ -61,7 +60,6 @@ static int db_test(char *dbpath)
 {
 	struct dirent *ent;
 	char path[PATH_MAX];
-	struct stat buf;
 	int ret = 0;
 
 	DIR *dir;
@@ -77,17 +75,17 @@ static int db_test(char *dbpath)
 		}
 		/* check for desc, depends, and files */
 		snprintf(path, PATH_MAX, "%s/%s/desc", dbpath, ent->d_name);
-		if(stat(path, &buf)) {
+		if(access(path, F_OK)) {
 			printf("%s: description file is missing\n", ent->d_name);
 			ret++;
 		}
 		snprintf(path, PATH_MAX, "%s/%s/depends", dbpath, ent->d_name);
-		if(stat(path, &buf)) {
+		if(access(path, F_OK)) {
 			printf("%s: dependency file is missing\n", ent->d_name);
 			ret++;
 		}
 		snprintf(path, PATH_MAX, "%s/%s/files", dbpath, ent->d_name);
-		if(stat(path, &buf)) {
+		if(access(path, F_OK)) {
 			printf("%s: file list is missing\n", ent->d_name);
 			ret++;
 		}