cache uid/gid during rule parsing

This cuts down the number of parsing /etc/group from ~700 to 11,
with some large rule files installed.

diff --git a/udev/test-udev.c b/udev/test-udev.c
index 76045132bf1af5100cc06c3d678d663ae80ac19c..ff1c353e6649d0e21e9d43df0087d8c0c4375c99 100644 (file)
--- a/udev/test-udev.c
+++ b/udev/test-udev.c
@@ -81,7 +81,7 @@ int main(int argc, char *argv[])
                goto exit;
        }
 
-       rules = udev_rules_new(udev, 0);
+       rules = udev_rules_new(udev, 1);
 
        util_strlcpy(syspath, udev_get_sys_path(udev), sizeof(syspath));
        util_strlcat(syspath, devpath, sizeof(syspath));

diff --git a/udev/udev-rules.c b/udev/udev-rules.c
index 535ec3f141975b6adbb9b353fbe07215c31f67f1..b19edc5ed68c03fc7e5981628d4e5d2e0f15dea2 100644 (file)
--- a/udev/udev-rules.c
+++ b/udev/udev-rules.c
@@ -31,6 +31,7 @@
 #define PREALLOC_TOKEN                 2048
 #define PREALLOC_STRBUF                        32 * 1024
 
+/* KEY=="", KEY!="", KEY+="", KEY="", KEY:="" */
 enum key_operation {
        KEY_OP_UNSET,
        KEY_OP_MATCH,
@@ -48,6 +49,7 @@ static const char *operation_str[] = {
        [KEY_OP_ASSIGN_FINAL] = "assign-final",
 };
 
+/* tokens of a rule are sorted/handled in this order */
 enum token_type {
        TK_UNDEF,
        TK_RULE,
@@ -187,19 +189,39 @@ struct rule_tmp {
        unsigned int token_cur;
 };
 
+struct uid_gid {
+       unsigned int name_off;
+       union {
+               uid_t   uid;
+               gid_t   gid;
+       };
+};
+
 struct udev_rules {
        struct udev *udev;
        int resolve_names;
+
+       /* every key in the rules file becomes a token */
        struct token *tokens;
        unsigned int token_cur;
        unsigned int token_max;
+
+       /* all key strings are copied to a single string buffer */
        char *buf;
        size_t buf_cur;
        size_t buf_max;
        unsigned int buf_count;
+
+       /* during rule parsing, we cache uid/gid lookup results */
+       struct uid_gid *uids;
+       unsigned int uids_cur;
+       unsigned int uids_max;
+       struct uid_gid *gids;
+       unsigned int gids_cur;
+       unsigned int gids_max;
 };
 
-/* we could lookup and return existing strings, or tails of strings */
+/* NOTE: we could lookup and return existing strings, or tails of strings */
 static int add_string(struct udev_rules *rules, const char *str)
 {
        size_t len = strlen(str)+1;
@@ -216,8 +238,8 @@ static int add_string(struct udev_rules *rules, const char *str)
 
                /* double the buffer size */
                add = rules->buf_max;
-               if (add < len)
-                       add = len * 2;
+               if (add < len * 8)
+                       add = len * 8;
 
                buf = realloc(rules->buf, rules->buf_max + add);
                if (buf == NULL)
@@ -243,8 +265,8 @@ static int add_token(struct udev_rules *rules, struct token *token)
 
                /* double the buffer size */
                add = rules->token_max;
-               if (add < 1)
-                       add = 2;
+               if (add < 8)
+                       add = 8;
 
                tokens = realloc(rules->tokens, (rules->token_max + add ) * sizeof(struct token));
                if (tokens == NULL)
@@ -258,6 +280,92 @@ static int add_token(struct udev_rules *rules, struct token *token)
        return 0;
 }
 
+static uid_t add_uid(struct udev_rules *rules, const char *owner)
+{
+       unsigned int i;
+       uid_t uid;
+       unsigned int off;
+
+       /* lookup, if we know it already */
+       for (i = 0; i < rules->uids_cur; i++) {
+               off = rules->uids[i].name_off;
+               if (strcmp(&rules->buf[off], owner) == 0) {
+                       uid = rules->uids[i].uid;
+                       dbg(rules->udev, "return existing %u for '%s'\n", uid, owner);
+                       return uid;
+               }
+       }
+       uid = util_lookup_user(rules->udev, owner);
+
+       /* grow buffer if needed */
+       if (rules->uids_cur+1 >= rules->uids_max) {
+               struct uid_gid *uids;
+               unsigned int add;
+
+               /* double the buffer size */
+               add = rules->uids_max;
+               if (add < 1)
+                       add = 8;
+
+               uids = realloc(rules->uids, (rules->uids_max + add ) * sizeof(struct uid_gid));
+               if (uids == NULL)
+                       return uid;
+               info(rules->udev, "extend uids from %u to %u\n", rules->uids_max, rules->uids_max + add);
+               rules->uids = uids;
+               rules->uids_max += add;
+       }
+       rules->uids[rules->uids_cur].uid = uid;
+       off = add_string(rules, owner);
+       if (off <= 0)
+               return uid;
+       rules->uids[rules->uids_cur].name_off = off;
+       rules->uids_cur++;
+       return uid;
+}
+
+static gid_t add_gid(struct udev_rules *rules, const char *group)
+{
+       unsigned int i;
+       gid_t gid;
+       unsigned int off;
+
+       /* lookup, if we know it already */
+       for (i = 0; i < rules->gids_cur; i++) {
+               off = rules->gids[i].name_off;
+               if (strcmp(&rules->buf[off], group) == 0) {
+                       gid = rules->gids[i].gid;
+                       info(rules->udev, "return existing %u for '%s'\n", gid, group);
+                       return gid;
+               }
+       }
+       gid = util_lookup_group(rules->udev, group);
+
+       /* grow buffer if needed */
+       if (rules->gids_cur+1 >= rules->gids_max) {
+               struct uid_gid *gids;
+               unsigned int add;
+
+               /* double the buffer size */
+               add = rules->gids_max;
+               if (add < 1)
+                       add = 8;
+
+               gids = realloc(rules->gids, (rules->gids_max + add ) * sizeof(struct uid_gid));
+               if (gids == NULL)
+                       return gid;
+               info(rules->udev, "extend gids from %u to %u\n", rules->gids_max, rules->gids_max + add);
+               rules->gids = gids;
+               rules->gids_max += add;
+       }
+       rules->gids[rules->gids_cur].gid = gid;
+       off = add_string(rules, group);
+       if (off <= 0)
+               return gid;
+       rules->gids[rules->gids_cur].name_off = off;
+       rules->gids_cur++;
+       return gid;
+}
+
 static int import_property_from_string(struct udev_device *dev, char *line)
 {
        struct udev *udev = udev_device_get_udev(dev);
@@ -1148,7 +1256,7 @@ static int add_rule(struct udev_rules *rules, char *line,
                        if (endptr[0] == '\0') {
                                rule_add_token(&rule_tmp, TK_A_OWNER_ID, op, NULL, &uid);
                        } else if (rules->resolve_names && strchr("$%", value[0]) == NULL) {
-                               uid = util_lookup_user(rules->udev, value);
+                               uid = add_uid(rules, value);
                                rule_add_token(&rule_tmp, TK_A_OWNER_ID, op, NULL, &uid);
                        } else {
                                rule_add_token(&rule_tmp, TK_A_OWNER, op, value, NULL);
@@ -1165,7 +1273,7 @@ static int add_rule(struct udev_rules *rules, char *line,
                        if (endptr[0] == '\0') {
                                rule_add_token(&rule_tmp, TK_A_GROUP_ID, op, NULL, &gid);
                        } else if (rules->resolve_names && strchr("$%", value[0]) == NULL) {
-                               gid = util_lookup_group(rules->udev, value);
+                               gid = add_gid(rules, value);
                                rule_add_token(&rule_tmp, TK_A_GROUP_ID, op, NULL, &gid);
                        } else {
                                rule_add_token(&rule_tmp, TK_A_GROUP, op, value, NULL);
@@ -1476,7 +1584,16 @@ struct udev_rules *udev_rules_new(struct udev *udev, int resolve_names)
        end_token.type = TK_END;
        add_token(rules, &end_token);
 
-       /* shrink allocate buffers */
+       /* link all TK_RULE tokens to be able to fast-forward to next TK_RULE */
+       prev_rule = 0;
+       for (i = 1; i < rules->token_cur; i++) {
+               if (rules->tokens[i].type == TK_RULE) {
+                       rules->tokens[prev_rule].rule.next_rule = i;
+                       prev_rule = i;
+               }
+       }
+
+       /* shrink allocated token and string buffer */
        if (rules->token_cur < rules->token_max) {
                struct token *tokens;
 
@@ -1498,14 +1615,16 @@ struct udev_rules *udev_rules_new(struct udev *udev, int resolve_names)
        info(udev, "shrunk to %lu bytes tokens (%u * %zu bytes), %zu bytes buffer\n",
             rules->token_max * sizeof(struct token), rules->token_max, sizeof(struct token), rules->buf_max);
 
-       /* link all TK_RULE tokens to be able to fast-forward to next TK_RULE */
-       prev_rule = 0;
-       for (i = 1; i < rules->token_cur; i++) {
-               if (rules->tokens[i].type == TK_RULE) {
-                       rules->tokens[prev_rule].rule.next_rule = i;
-                       prev_rule = i;
-               }
-       }
+       /* cleanup uid/gid cache */
+       free(rules->uids);
+       rules->uids = NULL;
+       rules->uids_cur = 0;
+       rules->uids_max = 0;
+       free(rules->gids);
+       rules->gids = NULL;
+       rules->gids_cur = 0;
+       rules->gids_max = 0;
+
        dump_rules(rules);
        return rules;
 }
@@ -1516,6 +1635,8 @@ void udev_rules_unref(struct udev_rules *rules)
                return;
        free(rules->tokens);
        free(rules->buf);
+       free(rules->uids);
+       free(rules->gids);
        free(rules);
 }
 

diff --git a/udev/udevadm-test.c b/udev/udevadm-test.c
index ceeead0c8af42e812c9a4a1e0dc2ba248ae08169..2c8e0bff98101083ba85c4008c2591d1d20f3186 100644 (file)
--- a/udev/udevadm-test.c
+++ b/udev/udevadm-test.c
@@ -89,7 +89,7 @@ int udevadm_test(struct udev *udev, int argc, char *argv[])
               "some values may be different, or not available at a simulation run.\n"
               "\n");
 
-       rules = udev_rules_new(udev, 0);
+       rules = udev_rules_new(udev, 1);
        if (rules == NULL) {
                fprintf(stderr, "error reading rules\n");
                rc = 1;