* Copyright © 2008 Florent Bruneau
*/
+#include <sys/mman.h>
+
#include "str.h"
#include "trie.h"
typedef struct trie_entry_t trie_entry_t;
struct trie_entry_t {
- char *c;
- int c_len;
- bool c_own;
-
- int* children;
- int children_len;
- int children_size;
+ int32_t c_offset;
+ int32_t c_len;
- bool locked;
+ int32_t children_offset;
+ int32_t children_len;
};
struct trie_t {
- trie_entry_t* entries;
- int entries_len;
- int entries_size;
+ trie_entry_t *entries;
+ int32_t entries_len;
+ int32_t entries_size;
+
+ char *c;
+ int32_t c_len;
+ int32_t c_size;
+
+ char **keys;
+ int32_t keys_len;
+ int32_t keys_size;
bool locked;
};
-trie_t *trie_new()
+trie_t *trie_new(void)
{
return p_new(trie_t, 1);
}
+static inline void trie_cleanup_build_data(trie_t *trie)
+{
+ for (int i = 0 ; i < trie->keys_len ; ++i) {
+ p_delete(&trie->keys[i]);
+ }
+ p_delete(&trie->keys);
+ trie->keys_len = trie->keys_size = 0;
+}
+
void trie_delete(trie_t **trie)
{
if (*trie) {
- for (int i = 0 ; i < (*trie)->entries_len ; ++i) {
- trie_entry_t *entry = &(*trie)->entries[i];
- if (entry->c_own) {
- p_delete(&entry->c);
- } else {
- entry->c = NULL;
- }
- p_delete(&(entry->children));
- }
+ trie_cleanup_build_data(*trie);
p_delete(&(*trie)->entries);
+ p_delete(&(*trie)->c);
p_delete(trie);
}
}
/** Check that the given entry is a prefix for the given key.
*/
-static inline bool trie_entry_c_match(const trie_entry_t* entry,
+static inline bool trie_entry_c_match(const trie_t *trie,
+ const trie_entry_t *entry,
const char *key, int *pos)
{
+ const char *c = trie->c + entry->c_offset;
int i = 0;
for (i = 0 ; i < entry->c_len ; ++i) {
- if (key[i] != entry->c[i]) {
+ if (key[i] != c[i]) {
if (pos) {
*pos = i;
}
return true;
}
+static inline bool trie_entry_match(const trie_t *trie,
+ const trie_entry_t *entry, const char *key)
+{
+ return !!(strcmp(trie->c + entry->c_offset, key) == 0);
+}
+
+static inline bool trie_entry_is_leaf(const trie_entry_t *entry)
+{
+ return entry->children_len == 0;
+}
+
/** Lookup for a child of entry matching the given entry at the given pos.
* Only the first character of the children is taken into account in the
* lookup. The current entry is assumed to match the key.
const trie_entry_t* entry,
const char *key)
{
- int start = 0;
- int end = entry->children_len;
+ int start = entry->children_offset;
+ int end = start + entry->children_len;
const char c = *key;
while (start < end) {
int mid = (start + end) / 2;
- trie_entry_t* child = &trie->entries[entry->children[mid]];
+ trie_entry_t* child = &trie->entries[mid];
+ const char c2 = trie->c[child->c_offset];
if (child->c_len) {
- if (child->c[0] == c) {
+ if (c2 == c) {
return child;
}
- if (c < child->c[0]) {
+ if (c < c2) {
end = mid;
} else {
start = mid + 1;
return NULL;
}
+#define GROW(Buffer, Added, Len, Size) \
+ do { \
+ const int required_size = (Len) + (Added); \
+ int next_size = (Size); \
+ if (next_size >= required_size) { \
+ break; \
+ } \
+ do { \
+ next_size = p_alloc_nr(next_size); \
+ } while (next_size < required_size); \
+ p_allocgrow(&(Buffer), next_size, &(Size)); \
+ } while(0)
+
static inline void trie_grow(trie_t *trie, int delta)
{
- int next_size = trie->entries_size;
- if (next_size > trie->entries_len + delta) {
- return;
- }
- do {
- next_size = p_alloc_nr(next_size);
- } while (trie->entries_len + delta > next_size);
- p_allocgrow(&trie->entries, next_size, &trie->entries_size);
+ GROW(trie->entries, delta, trie->entries_len, trie->entries_size);
}
static inline int trie_entry_new(trie_t *trie)
static inline int trie_add_leaf(trie_t *trie, const char *key)
{
trie_entry_t *entry;
+ int len = m_strlen(key) + 1;
entry = &trie->entries[trie_entry_new(trie)];
- entry->c = strdup(key); /* don't use m_strdup
- since m_strdup("") == NULL */
- entry->c_len = m_strlen(key) + 1;
- entry->c_own = true;
+ GROW(trie->c, len, trie->c_len, trie->c_size);
+ memcpy(trie->c + trie->c_len, key, len);
+ entry->c_offset = trie->c_len;
+ entry->c_len = len;
+ trie->c_len += len;
return trie->entries_len - 1;
}
static inline void trie_entry_insert_child(trie_t *trie, trie_entry_t *entry,
int pchild)
{
- const char c = trie->entries[pchild].c[0];
- int start = 0;
- int end = entry->children_len;
-
- p_allocgrow(&entry->children, entry->children_len + 1, &entry->children_size);
- while (start < end) {
- int mid = (start + end) / 2;
- trie_entry_t* child = &trie->entries[entry->children[mid]];
-
- if (child->c_len) {
- if (child->c[0] == c) {
- abort();
- }
- if (c < child->c[0]) {
- end = mid;
- } else {
- start = mid + 1;
- }
- } else {
+ if (entry->children_len == 0) {
+ entry->children_offset = pchild;
+ entry->children_len = 1;
+ } else {
+ if (entry->children_offset + entry->children_len != pchild) {
+ printf("Inserting child %d while offset is %d[%d]\n",
+ pchild, entry->children_offset, entry->children_len);
abort();
}
+ ++entry->children_len;
}
- memmove(entry->children + start + 1,
- entry->children + start,
- sizeof(int) * (entry->children_len - start));
- entry->children[start] = pchild;
- ++entry->children_len;
}
static inline void trie_entry_split(trie_t *trie, trie_entry_t *entry, int pos)
trie_entry_t *child;
child = &trie->entries[trie_entry_new(trie)];
if (pos == 0) {
- child->c = entry->c;
- child->c_len = entry->c_len;
- child->c_own = entry->c_own;
- entry->c = NULL;
- entry->c_len = 0;
- entry->c_own = false;
+ child->c_offset = entry->c_offset;
+ child->c_len = entry->c_len;
+ entry->c_offset = 0;
+ entry->c_len = 0;
} else {
- child->c = entry->c + pos;
- child->c_len = entry->c_len - pos;
- child->c_own = false;
- entry->c_len = pos;
+ child->c_offset = entry->c_offset + pos;
+ child->c_len = entry->c_len - pos;
+ entry->c_len = pos;
}
- child->children = entry->children;
- child->children_len = entry->children_len;
- child->children_size = entry->children_size;
- entry->children = NULL;
- entry->children_len = 0;
- entry->children_size = 0;
- trie_entry_insert_child(trie, entry, trie->entries_len - 1);
+ child->children_offset = entry->children_offset;
+ child->children_len = entry->children_len;
+ entry->children_offset = trie->entries_len - 1;
+ entry->children_len = 1;
}
void trie_insert(trie_t *trie, const char* key)
{
- trie_grow(trie, 2);
- if (trie->entries_len == 0) {
- (void)trie_add_leaf(trie, key);
- } else {
- trie_entry_t *current = trie->entries;
- while (true) {
- int pos = 0;
- if (trie_entry_c_match(current, key, &pos)) {
- if (current->c_len && current->c[current->c_len - 1] == '\0') {
- return;
- }
- trie_entry_t *next = NULL;
- key += pos;
- next = trie_entry_child(trie, current, key);
- if (next == NULL) {
- trie_entry_insert_child(trie, current,
- trie_add_leaf(trie, key));
- return;
- } else {
- current = next;
+ assert(trie->entries == NULL && "Trie already compiled");
+ GROW(trie->keys, 1, trie->keys_len, trie->keys_size);
+ trie->keys[trie->keys_len++] = strdup(key);
+}
+
+
+static inline void trie_compile_aux(trie_t *trie, int id,
+ int first_key, int last_key, int offset,
+ int initial_diff)
+{
+ int forks[256];
+ int fork_pos = 0;
+ char current = '\0';
+
+ for (int off_diff = initial_diff ; fork_pos == 0 ; ++off_diff, ++offset) {
+ current = trie->keys[first_key][offset];
+ for (int i = first_key + 1 ; i < last_key ; ++i) {
+ if (trie->keys[i][offset] != current) {
+ trie_grow(trie, 2);
+ if (fork_pos == 0) {
+ trie_entry_split(trie, &trie->entries[id], off_diff);
}
- } else {
- trie_entry_split(trie, current, pos);
- trie_entry_insert_child(trie, current,
- trie_add_leaf(trie, key + pos));
- return;
+ trie_entry_insert_child(trie, &trie->entries[id],
+ trie_add_leaf(trie, trie->keys[i] +
+ offset));
+ forks[fork_pos++] = i;
+ current = trie->keys[i][offset];
}
}
+ if (fork_pos == 0 && current == '\0') {
+ return;
+ }
+ }
+ forks[fork_pos] = last_key;
+
+ const int children_len = trie->entries[id].children_len;
+ for (int i = 0 ; i < children_len ; ++i) {
+ int child = trie->entries[id].children_offset + i;
+ if (forks[i] - 1 > first_key) {
+ trie_compile_aux(trie, child, first_key, forks[i], offset, 1);
+ }
+ first_key = forks[i];
+ }
+}
+
+
+static inline void trie_shrink(trie_t *trie)
+{
+ p_shrink(&trie->entries, trie->entries_len, &trie->entries_size);
+ p_shrink(&trie->c, trie->c_len, &trie->c_size);
+}
+
+static inline void trie_lock(trie_t *trie)
+{
+ if (mlock(trie->entries, sizeof(trie_entry_t) * trie->entries_len) != 0) {
+ UNIXERR("mlock");
+ return;
+ }
+ if (mlock(trie->c, trie->c_len) != 0) {
+ UNIXERR("mlock");
+ munlock(trie->entries, sizeof(trie_entry_t) * trie->entries_len);
+ return;
+ }
+ trie->locked = true;
+}
+
+typedef char *str_t;
+
+void trie_compile(trie_t *trie, bool memlock)
+{
+ assert(trie->entries == NULL && "Trie already compiled");
+ assert(trie->keys != NULL && "Trying to compile an empty trie");
+ {
+# define QSORT_TYPE str_t
+# define QSORT_BASE trie->keys
+# define QSORT_NELT trie->keys_len
+# define QSORT_LT(a,b) strcmp(*a, *b) < 0
+# include "qsort.c"
+ }
+
+ trie_grow(trie, trie->keys_len);
+ trie_compile_aux(trie, trie_add_leaf(trie, trie->keys[0]),
+ 0, trie->keys_len, 0, 0);
+ trie_cleanup_build_data(trie);
+ trie_shrink(trie);
+ if (memlock) {
+ trie_lock(trie);
}
}
bool trie_lookup(const trie_t *trie, const char *key)
{
+ assert(trie->keys == NULL && "Can't lookup: trie not compiled");
if (trie->entries_len == 0) {
return false;
} else {
trie_entry_t *current = trie->entries;
while (true) {
int pos = 0;
- if (trie_entry_c_match(current, key, &pos)) {
- if (current->c_len && current->c[current->c_len - 1] == '\0') {
- return true;
- }
+ if (trie_entry_is_leaf(current)) {
+ return trie_entry_match(trie, current, key);
+ } else if (trie_entry_c_match(trie, current, key, &pos)) {
key += pos;
current = trie_entry_child(trie, current, key);
if (current == NULL) {
/* Debug {{{1
*/
-static inline void trie_entry_inspect(const trie_t *trie,
+static inline void trie_entry_inspect(const trie_t *trie, bool show_content,
const trie_entry_t *entry, int level)
{
- for (int i = 0 ; i < level ; ++i) {
- fputs(" ", stdout);
+ static int max_depth = 0;
+ static int leaves = 0;
+ static int depth_sum = 0;
+
+ if (trie_entry_is_leaf(entry)) {
+ if (level > max_depth) {
+ max_depth = level;
+ }
+ ++leaves;
+ depth_sum += level;
}
- if (entry->c == NULL) {
- fputs("(nil)", stdout);
- } else {
- for (int i = 0 ; i < entry->c_len ; ++i) {
- if (entry->c[i]) {
- printf("%c ", entry->c[i]);
- } else {
- fputs("\\0 ", stdout);
+ if (show_content) {
+ for (int i = 0 ; i < level ; ++i) {
+ fputs(" ", stdout);
+ }
+ if (entry->c_len == 0) {
+ fputs("(nil)", stdout);
+ } else {
+ const char *c = trie->c + entry->c_offset;
+ printf("(%d) ", entry->c_len);
+ for (int i = 0 ; i < entry->c_len ; ++i) {
+ if (c[i]) {
+ printf("%c ", c[i]);
+ } else {
+ fputs("\\0 ", stdout);
+ }
}
}
+ fputs("\n", stdout);
+ }
+ for (int i = entry->children_offset ;
+ i < entry->children_offset + entry->children_len ; ++i) {
+ trie_entry_inspect(trie, show_content, &trie->entries[i], level + 1);
}
- fputs("\n", stdout);
- for (int i = 0 ; i < entry->children_len ; ++i) {
- trie_entry_inspect(trie, &trie->entries[entry->children[i]], level + 1);
+ if (level == 0) {
+ printf("Average char per node: %d\n", trie->c_len / trie->entries_len);
+ printf("Number of nodes: %d\n", trie->entries_len);
+ printf("Number of leaves: %d\n", leaves);
+ printf("Max depth: %d\n", max_depth);
+ printf("Average leaf depth: %d\n", depth_sum / leaves);
+ printf("Memory used: %d\n", (trie->entries_size * sizeof(trie_entry_t))
+ + (trie->c_size) + sizeof(trie_t));
}
}
-void trie_inspect(const trie_t *trie)
+void trie_inspect(const trie_t *trie, bool show_content)
{
- trie_entry_inspect(trie, trie->entries, 0);
+ trie_entry_inspect(trie, show_content, trie->entries, 0);
}
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