*/
#include <stddef.h>
+#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#define PREALLOC_TOKEN 2048
#define PREALLOC_STRBUF 32 * 1024
+#define PREALLOC_TRIE 256
struct uid_gid {
unsigned int name_off;
};
};
-/* KEY=="", KEY!="", KEY+="", KEY="", KEY:="" */
+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;
+ unsigned short value_len;
+};
+
struct udev_rules {
struct udev *udev;
int resolve_names;
size_t buf_max;
unsigned int buf_count;
- /* during rule parsing, we cache uid/gid lookup results */
+ /* 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, uid/gid lookup results are cached */
struct uid_gid *uids;
unsigned int uids_cur;
unsigned int uids_max;
unsigned int gids_max;
};
+/* KEY=="", KEY!="", KEY+="", KEY="", KEY:="" */
enum operation_type {
OP_UNSET,
static inline void dump_rules(struct udev_rules *rules) {}
#endif /* DEBUG */
-/* we could lookup and return existing strings, or tails of strings */
-static int add_string(struct udev_rules *rules, const char *str)
+static int add_new_string(struct udev_rules *rules, const char *str, size_t bytes)
{
- size_t len = strlen(str)+1;
int off;
- /* offset 0 is always '\0' */
- if (str[0] == '\0')
- return 0;
-
/* grow buffer if needed */
- if (rules->buf_cur + len+1 >= rules->buf_max) {
+ if (rules->buf_cur + bytes+1 >= rules->buf_max) {
char *buf;
unsigned int add;
/* double the buffer size */
add = rules->buf_max;
- if (add < len * 8)
- add = len * 8;
+ if (add < bytes * 8)
+ add = bytes * 8;
buf = realloc(rules->buf, rules->buf_max + add);
if (buf == NULL)
rules->buf_max += add;
}
off = rules->buf_cur;
- memcpy(&rules->buf[rules->buf_cur], str, len);
- rules->buf_cur += len;
+ memcpy(&rules->buf[rules->buf_cur], str, bytes);
+ rules->buf_cur += bytes;
rules->buf_count++;
return off;
}
-static int add_token(struct udev_rules *rules, struct token *token)
+static int add_string(struct udev_rules *rules, const char *str)
{
+ unsigned int node_idx;
+ struct trie_node *new_node;
+ unsigned int new_node_idx;
+ unsigned char key;
+ unsigned short len;
+ unsigned int depth;
+ unsigned int off;
+
+ len = strlen(str);
+
+ /* offset 0 is always '\0' */
+ if (len == 0)
+ return 0;
+
+ /* descend root - start from last character of str */
+ key = str[len - 1];
+ node_idx = rules->trie_root[key];
+ depth = 0;
+
+ /* descend suffix trie */
+ if (node_idx > 0) {
+ while (1) {
+ 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))
+ return off;
+
+ /* lookup child node */
+ key = str[len - 1 - depth];
+ 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_idx = rules->trie_childs[child_idx].node_idx;
+ }
+ }
+
+ /* string not found, add it */
+ off = add_new_string(rules, str, len + 1);
+
+ /* 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_nodes_max;
+ if (add < 8)
+ add = 8;
+
+ nodes = realloc(rules->trie_nodes, (rules->trie_nodes_max + add) * sizeof(struct trie_node));
+ if (nodes == NULL)
+ return -1;
+ 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;
+ }
+
+ /* grow trie childs if needed */
+ if (rules->trie_childs_cur >= rules->trie_childs_max) {
+ struct trie_child *childs;
+ unsigned int add;
+
+ /* double the buffer size */
+ add = rules->trie_childs_max;
+ if (add < 8)
+ add = 8;
+
+ 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;
+ }
+
+ /* 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;
+}
+static int add_token(struct udev_rules *rules, struct token *token)
+{
/* grow buffer if needed */
if (rules->token_cur+1 >= rules->token_max) {
struct token *tokens;
if (rules->tokens == NULL)
return NULL;
rules->token_max = PREALLOC_TOKEN;
+
rules->buf = malloc(PREALLOC_STRBUF);
if (rules->buf == NULL)
return NULL;
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;
+ /* offset 0 is reserved for the null child node */
+ rules->trie_childs_cur = 1;
+
+ 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");
rules->buf_max = rules->buf_cur;
}
}
- info(udev, "shrunk to %zu bytes tokens (%u * %zu bytes), %zu bytes buffer\n",
+ info(udev, "rules use %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, "temporary index used %zu bytes (%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_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;
/* cleanup uid/gid cache */
free(rules->uids);
return;
free(rules->tokens);
free(rules->buf);
+ free(rules->trie_nodes);
+ free(rules->trie_childs);
+ free(rules->trie_root);
free(rules->uids);
free(rules->gids);
free(rules);
~ianmdlvl / elogind.git / blobdiff