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authorKay Sievers <kay.sievers@vrfy.org>2008-11-12 05:50:05 +0100
committerKay Sievers <kay.sievers@vrfy.org>2008-11-12 05:50:05 +0100
commitbcf44d55762557096fdd627b14415e35f3a4e14d (patch)
tree42279e4645cca8eb9c460bd959bf6907895f410c /udev
parent1c8af93aca64033f00d493bad7d505757c1ab414 (diff)
string index - split nodes and childs to allow and unlimited number of childs
Diffstat (limited to 'udev')
-rw-r--r--udev/udev-rules.c216
1 files changed, 127 insertions, 89 deletions
diff --git a/udev/udev-rules.c b/udev/udev-rules.c
index dc4009f74a..efd8310cd0 100644
--- a/udev/udev-rules.c
+++ b/udev/udev-rules.c
@@ -41,14 +41,17 @@ struct uid_gid {
};
};
-#define TRIE_CHILD_MAX 10
+struct trie_child {
+ unsigned int next_idx;
+ unsigned int node_idx;
+ unsigned char key;
+};
struct trie_node {
+ unsigned int child_idx;
+ unsigned int last_child_idx;
unsigned int value_off;
- size_t value_len;
- unsigned char child_cur;
- unsigned char child_key[TRIE_CHILD_MAX];
- unsigned short child[TRIE_CHILD_MAX];
+ unsigned short value_len;
};
struct udev_rules {
@@ -66,13 +69,16 @@ struct udev_rules {
size_t buf_max;
unsigned int buf_count;
- /* key strings are indexed to avoid wasting space with duplicates */
- struct trie_node *trie;
- unsigned short trie_cur;
- unsigned short trie_max;
- unsigned short *trie_root;
+ /* during rule parsing, strings are indexed to find duplicates */
+ unsigned int *trie_root;
+ struct trie_node *trie_nodes;
+ unsigned int trie_nodes_cur;
+ unsigned int trie_nodes_max;
+ struct trie_child *trie_childs;
+ unsigned int trie_childs_cur;
+ unsigned int trie_childs_max;
- /* during rule parsing, we cache uid/gid lookup results */
+ /* during rule parsing, uid/gid lookup results are cached */
struct uid_gid *uids;
unsigned int uids_cur;
unsigned int uids_max;
@@ -438,25 +444,13 @@ static int add_new_string(struct udev_rules *rules, const char *str, size_t byte
return off;
}
-static unsigned char trie_child_slot(struct trie_node *node, char key)
-{
- unsigned char child_slot;
-
- for (child_slot = 0; child_slot < node->child_cur; child_slot++) {
- if (node->child_key[child_slot] == key)
- break;
- }
-
- return child_slot;
-}
-
static int add_string(struct udev_rules *rules, const char *str)
{
- struct trie_node *child;
- unsigned short child_off;
- unsigned short node_off;
+ unsigned int node_idx;
+ struct trie_node *new_node;
+ unsigned int new_node_idx;
unsigned char key;
- size_t len;
+ unsigned short len;
unsigned int depth;
unsigned int off;
@@ -466,89 +460,118 @@ static int add_string(struct udev_rules *rules, const char *str)
if (len == 0)
return 0;
- /* strings with spaces are probably commands e.g. modprobe,
- with unique arguments. */
- if (strchr(str, ' ') != NULL)
- return add_new_string(rules, str, len + 1);
-
/* descend root - start from last character of str */
key = str[len - 1];
- node_off = rules->trie_root[key];
+ node_idx = rules->trie_root[key];
depth = 0;
/* descend suffix trie */
- if (node_off != 0) {
+ if (node_idx > 0) {
while (1) {
- struct trie_node *node = &rules->trie[node_off];
- unsigned char child_slot;
+ struct trie_node *node;
+ unsigned int child_idx;
+ node = &rules->trie_nodes[node_idx];
depth++;
off = node->value_off + node->value_len - len;
/* match against current node */
- if (depth == len ||
- (node->value_len >= len &&
- memcmp(&rules->buf[off], str, len) == 0))
- {
+ if (depth == len || (node->value_len >= len && memcmp(&rules->buf[off], str, len) == 0))
return off;
- }
/* lookup child node */
key = str[len - 1 - depth];
- child_slot = trie_child_slot(node, key);
-
- if(child_slot == node->child_cur)
+ child_idx = node->child_idx;
+ while (child_idx > 0) {
+ if (rules->trie_childs[child_idx].key == key)
+ break;
+ child_idx = rules->trie_childs[child_idx].next_idx;
+ }
+ if (child_idx == 0)
break;
-
- node_off = node->child[child_slot];
+ node_idx = rules->trie_childs[child_idx].node_idx;
}
}
/* string not found, add it */
off = add_new_string(rules, str, len + 1);
- /* grow trie storage if needed */
- if (rules->trie_cur >= rules->trie_max) {
- struct trie_node *trie;
- unsigned short add;
+ /* grow trie nodes if needed */
+ if (rules->trie_nodes_cur >= rules->trie_nodes_max) {
+ struct trie_node *nodes;
+ unsigned int add;
/* double the buffer size */
- add = rules->trie_max;
+ add = rules->trie_nodes_max;
if (add < 8)
add = 8;
- trie = realloc(rules->trie, (rules->trie_max + add) * sizeof(struct trie_node));
- if (trie == NULL)
+ nodes = realloc(rules->trie_nodes, (rules->trie_nodes_max + add) * sizeof(struct trie_node));
+ if (nodes == NULL)
return -1;
- dbg(rules->udev, "extend string index nodes from %u to %u\n", rules->trie_max, rules->trie_max + add);
- rules->trie = trie;
- rules->trie_max += add;
+ dbg(rules->udev, "extend trie nodes from %u to %u\n",
+ rules->trie_nodes_max, rules->trie_nodes_max + add);
+ rules->trie_nodes = nodes;
+ rules->trie_nodes_max += add;
}
- /* insert new child node */
- child_off = rules->trie_cur;
- if (depth == 0) {
- rules->trie_root[key] = child_off;
- } else {
- struct trie_node *parent = &rules->trie[node_off];
- unsigned char child_slot = parent->child_cur;
+ /* grow trie childs if needed */
+ if (rules->trie_childs_cur >= rules->trie_childs_max) {
+ struct trie_child *childs;
+ unsigned int add;
- /* no space in parent, we can't index this string, nevermind */
- if (child_slot == TRIE_CHILD_MAX)
- return off;
+ /* double the buffer size */
+ add = rules->trie_childs_max;
+ if (add < 8)
+ add = 8;
- parent->child[child_slot] = child_off;
- parent->child_key[child_slot] = key;
- parent->child_cur = child_slot + 1;
+ childs = realloc(rules->trie_childs, (rules->trie_childs_max + add) * sizeof(struct trie_child));
+ if (childs == NULL)
+ return -1;
+ dbg(rules->udev, "extend trie childs from %u to %u\n",
+ rules->trie_childs_max, rules->trie_childs_max + add);
+ rules->trie_childs = childs;
+ rules->trie_childs_max += add;
}
- /* allocate and construct the child node */
- rules->trie_cur++;
- child = &rules->trie[child_off];
- memset(child, 0x00, sizeof(struct trie_node));
- child->value_off = off;
- child->value_len = len;
+ /* get new node */
+ new_node_idx = rules->trie_nodes_cur;
+ rules->trie_nodes_cur++;
+ new_node = &rules->trie_nodes[new_node_idx];
+ new_node->value_off = off;
+ new_node->value_len = len;
+ new_node->child_idx = 0;
+ new_node->last_child_idx = 0;
+ if (depth == 0) {
+ /* add node to root */
+ rules->trie_root[key] = new_node_idx;
+ } else {
+ /* add node to parent */
+ struct trie_node *parent;
+ struct trie_child *new_child;
+ unsigned int new_child_idx;
+
+ /* get new child link for list of childs of parent */
+ new_child_idx = rules->trie_childs_cur;
+ rules->trie_childs_cur++;
+ new_child = &rules->trie_childs[new_child_idx];
+ new_child->next_idx = 0;
+ new_child->node_idx = new_node_idx;
+ new_child->key = key;
+
+ /* append child link to list of childs of parent */
+ parent = &rules->trie_nodes[node_idx];
+ if (parent->child_idx == 0) {
+ parent->child_idx = new_child_idx;
+ } else {
+ struct trie_child *last_child;
+
+ last_child = &rules->trie_childs[parent->last_child_idx];
+ last_child->next_idx = new_child_idx;
+ }
+ parent->last_child_idx = new_child_idx;
+ }
return off;
}
@@ -1728,23 +1751,31 @@ struct udev_rules *udev_rules_new(struct udev *udev, int resolve_names)
if (rules->tokens == NULL)
return NULL;
rules->token_max = PREALLOC_TOKEN;
+
rules->buf = malloc(PREALLOC_STRBUF);
if (rules->buf == NULL)
return NULL;
rules->buf_max = PREALLOC_STRBUF;
- rules->trie = malloc(PREALLOC_TRIE * sizeof(struct trie_node));
- if (rules->trie == NULL)
- return NULL;
- rules->trie_max = PREALLOC_TRIE;
- rules->trie_root = calloc(UCHAR_MAX + 1, sizeof(unsigned short));
/* offset 0 is always '\0' */
rules->buf[0] = '\0';
rules->buf_cur = 1;
- /* offset 0 is reserved for the null trie node */
- rules->trie_cur = 1;
dbg(udev, "prealloc %zu bytes tokens (%u * %zu bytes), %zu bytes buffer\n",
rules->token_max * sizeof(struct token), rules->token_max, sizeof(struct token), rules->buf_max);
+ rules->trie_nodes = malloc(PREALLOC_TRIE * sizeof(struct trie_node));
+ if (rules->trie_nodes == NULL)
+ return NULL;
+ rules->trie_nodes_max = PREALLOC_TRIE;
+ /* offset 0 is reserved for the null trie node */
+ rules->trie_nodes_cur = 1;
+
+ rules->trie_childs = malloc(PREALLOC_TRIE * sizeof(struct trie_child));
+ if (rules->trie_childs == NULL)
+ return NULL;
+ rules->trie_childs_max = PREALLOC_TRIE;
+
+ rules->trie_root = calloc(UCHAR_MAX + 1, sizeof(unsigned short));
+
if (udev_get_rules_path(udev) != NULL) {
/* custom rules location for testing */
add_matching_files(udev, &file_list, udev_get_rules_path(udev), ".rules");
@@ -1857,14 +1888,20 @@ struct udev_rules *udev_rules_new(struct udev *udev, int resolve_names)
}
info(udev, "shrunk to %zu bytes tokens (%u * %zu bytes), %zu bytes buffer\n",
rules->token_max * sizeof(struct token), rules->token_max, sizeof(struct token), rules->buf_max);
- info(udev, "used %zu bytes of string index nodes (%hu * %zu bytes)\n",
- rules->trie_cur * sizeof(struct trie_node), rules->trie_cur, sizeof(struct trie_node));
+ info(udev, "used %zu bytes for index (%u * %zu bytes nodes, %u * %zu bytes child links)\n",
+ rules->trie_nodes_cur * sizeof(struct trie_node) + rules->trie_childs_cur * sizeof(struct trie_child),
+ rules->trie_nodes_cur, sizeof(struct trie_node),
+ rules->trie_childs_cur, sizeof(struct trie_child));
/* cleanup trie */
- free(rules->trie);
- rules->trie = NULL;
- rules->trie_cur = 0;
- rules->trie_max = 0;
+ free(rules->trie_nodes);
+ rules->trie_nodes = NULL;
+ rules->trie_nodes_cur = 0;
+ rules->trie_nodes_max = 0;
+ free(rules->trie_childs);
+ rules->trie_childs = NULL;
+ rules->trie_childs_cur = 0;
+ rules->trie_childs_max = 0;
free(rules->trie_root);
rules->trie_root = NULL;
@@ -1888,7 +1925,8 @@ void udev_rules_unref(struct udev_rules *rules)
return;
free(rules->tokens);
free(rules->buf);
- free(rules->trie);
+ free(rules->trie_nodes);
+ free(rules->trie_childs);
free(rules->trie_root);
free(rules->uids);
free(rules->gids);