util: place a couple of _likely_ around cache TLS vars

[elogind.git] / src / util.c

diff --git a/src/util.c b/src/util.c
index 3a82ef7600f53453416eb487b076c4415c1172a4..8d54049754c0495b2d4394483c9d2825fcc84f73 100644 (file)
--- a/src/util.c
+++ b/src/util.c
@@ -54,6 +54,7 @@
 #include <sys/time.h>
 #include <linux/rtc.h>
 #include <glob.h>
+#include <grp.h>
 
 #include "macro.h"
 #include "util.h"
@@ -72,7 +73,7 @@ size_t page_size(void) {
         static __thread size_t pgsz = 0;
         long r;
 
-        if (pgsz)
+        if (_likely_(pgsz))
                 return pgsz;
 
         assert_se((r = sysconf(_SC_PAGESIZE)) > 0);
@@ -808,7 +809,7 @@ int parse_env_file(
                 const char *separator, ...) {
 
         int r = 0;
-        char *contents, *p;
+        char *contents = NULL, *p;
 
         assert(fname);
         assert(separator);
@@ -1265,8 +1266,6 @@ bool is_path(const char *p) {
 }
 
 char *path_make_absolute(const char *p, const char *prefix) {
-        char *r;
-
         assert(p);
 
         /* Makes every item in the list an absolute path by prepending
@@ -1275,10 +1274,7 @@ char *path_make_absolute(const char *p, const char *prefix) {
         if (path_is_absolute(p) || !prefix)
                 return strdup(p);
 
-        if (asprintf(&r, "%s/%s", prefix, p) < 0)
-                return NULL;
-
-        return r;
+        return join(prefix, "/", p, NULL);
 }
 
 char *path_make_absolute_cwd(const char *p) {
@@ -1410,21 +1406,18 @@ int reset_all_signal_handlers(void) {
 }
 
 char *strstrip(char *s) {
-        char *e, *l = NULL;
+        char *e;
 
         /* Drops trailing whitespace. Modifies the string in
          * place. Returns pointer to first non-space character */
 
         s += strspn(s, WHITESPACE);
 
-        for (e = s; *e; e++)
-                if (!strchr(WHITESPACE, *e))
-                        l = e;
+        for (e = strchr(s, 0); e > s; e --)
+                if (!strchr(WHITESPACE, e[-1]))
+                        break;
 
-        if (l)
-                *(l+1) = 0;
-        else
-                *s = 0;
+        *e = 0;
 
         return s;
 }
@@ -3775,7 +3768,7 @@ int columns(void) {
         static __thread int parsed_columns = 0;
         const char *e;
 
-        if (parsed_columns > 0)
+        if (_likely_(parsed_columns > 0))
                 return parsed_columns;
 
         if ((e = getenv("COLUMNS")))
@@ -4371,7 +4364,7 @@ int detect_virtualization(const char **id) {
         const char *_id;
         int r;
 
-        if (cached_id) {
+        if (_likely_(cached_id)) {
 
                 if (cached_id == (const char*) -1)
                         return 0;
@@ -5266,18 +5259,21 @@ int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **h
 
         assert(username);
         assert(*username);
-        assert(uid);
-        assert(gid);
-        assert(home);
 
         /* We enforce some special rules for uid=0: in order to avoid
          * NSS lookups for root we hardcode its data. */
 
         if (streq(*username, "root") || streq(*username, "0")) {
                 *username = "root";
-                *uid = 0;
-                *gid = 0;
-                *home = "/root";
+
+                if (uid)
+                        *uid = 0;
+
+                if (gid)
+                        *gid = 0;
+
+                if (home)
+                        *home = "/root";
                 return 0;
         }
 
@@ -5300,9 +5296,53 @@ int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **h
         if (!p)
                 return errno != 0 ? -errno : -ESRCH;
 
-        *uid = p->pw_uid;
-        *gid = p->pw_gid;
-        *home = p->pw_dir;
+        if (uid)
+                *uid = p->pw_uid;
+
+        if (gid)
+                *gid = p->pw_gid;
+
+        if (home)
+                *home = p->pw_dir;
+
+        return 0;
+}
+
+int get_group_creds(const char **groupname, gid_t *gid) {
+        struct group *g;
+        gid_t id;
+
+        assert(groupname);
+
+        /* We enforce some special rules for gid=0: in order to avoid
+         * NSS lookups for root we hardcode its data. */
+
+        if (streq(*groupname, "root") || streq(*groupname, "0")) {
+                *groupname = "root";
+
+                if (gid)
+                        *gid = 0;
+
+                return 0;
+        }
+
+        if (parse_gid(*groupname, &id) >= 0) {
+                errno = 0;
+                g = getgrgid(id);
+
+                if (g)
+                        *groupname = g->gr_name;
+        } else {
+                errno = 0;
+                g = getgrnam(*groupname);
+        }
+
+        if (!g)
+                return errno != 0 ? -errno : -ESRCH;
+
+        if (gid)
+                *gid = g->gr_gid;
+
         return 0;
 }
 
@@ -5384,7 +5424,10 @@ int get_files_in_directory(const char *path, char ***list) {
         char **l = NULL;
 
         assert(path);
-        assert(list);
+
+        /* Returns all files in a directory in *list, and the number
+         * of files as return value. If list is NULL returns only the
+         * number */
 
         d = opendir(path);
         for (;;) {
@@ -5405,42 +5448,103 @@ int get_files_in_directory(const char *path, char ***list) {
                 if (!dirent_is_file(de))
                         continue;
 
-                if ((unsigned) r >= n) {
-                        char **t;
+                if (list) {
+                        if ((unsigned) r >= n) {
+                                char **t;
 
-                        n = MAX(16, 2*r);
-                        t = realloc(l, sizeof(char*) * n);
-                        if (!t) {
-                                r = -ENOMEM;
-                                goto finish;
-                        }
+                                n = MAX(16, 2*r);
+                                t = realloc(l, sizeof(char*) * n);
+                                if (!t) {
+                                        r = -ENOMEM;
+                                        goto finish;
+                                }
 
-                        l = t;
-                }
+                                l = t;
+                        }
 
-                assert((unsigned) r < n);
+                        assert((unsigned) r < n);
 
-                l[r] = strdup(de->d_name);
-                if (!l[r]) {
-                        r = -ENOMEM;
-                        goto finish;
-                }
+                        l[r] = strdup(de->d_name);
+                        if (!l[r]) {
+                                r = -ENOMEM;
+                                goto finish;
+                        }
 
-                l[++r] = NULL;
+                        l[++r] = NULL;
+                } else
+                        r++;
         }
 
 finish:
         if (d)
                 closedir(d);
 
-        if (r >= 0)
-                *list = l;
-        else
+        if (r >= 0) {
+                if (list)
+                        *list = l;
+        } else
                 strv_free(l);
 
         return r;
 }
 
+char *join(const char *x, ...) {
+        va_list ap;
+        size_t l;
+        char *r, *p;
+
+        va_start(ap, x);
+
+        if (x) {
+                l = strlen(x);
+
+                for (;;) {
+                        const char *t;
+
+                        t = va_arg(ap, const char *);
+                        if (!t)
+                                break;
+
+                        l += strlen(t);
+                }
+        } else
+                l = 0;
+
+        va_end(ap);
+
+        r = new(char, l+1);
+        if (!r)
+                return NULL;
+
+        if (x) {
+                p = stpcpy(r, x);
+
+                va_start(ap, x);
+
+                for (;;) {
+                        const char *t;
+
+                        t = va_arg(ap, const char *);
+                        if (!t)
+                                break;
+
+                        p = stpcpy(p, t);
+                }
+        } else
+                r[0] = 0;
+
+        return r;
+}
+
+bool is_main_thread(void) {
+        static __thread int cached = 0;
+
+        if (_unlikely_(cached == 0))
+                cached = getpid() == gettid() ? 1 : -1;
+
+        return cached > 0;
+}
+
 static const char *const ioprio_class_table[] = {
         [IOPRIO_CLASS_NONE] = "none",
         [IOPRIO_CLASS_RT] = "realtime",