1 /******************************************************************************/
2 /* pfixtools: a collection of postfix related tools */
4 /* ________________________________________________________________________ */
6 /* Redistribution and use in source and binary forms, with or without */
7 /* modification, are permitted provided that the following conditions */
10 /* 1. Redistributions of source code must retain the above copyright */
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12 /* 2. Redistributions in binary form must reproduce the above copyright */
13 /* notice, this list of conditions and the following disclaimer in the */
14 /* documentation and/or other materials provided with the distribution. */
15 /* 3. The names of its contributors may not be used to endorse or promote */
16 /* products derived from this software without specific prior written */
19 /* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND */
20 /* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE */
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29 /* THE POSSIBILITY OF SUCH DAMAGE. */
30 /******************************************************************************/
33 * Copyright © 2008 Florent Bruneau
40 typedef struct trie_entry_t trie_entry_t;
44 uint32_t children_offset;
47 uint16_t children_len;
49 #define TRIE_ENTRY_INIT { 0, 0, 0, 0 }
53 A(trie_entry_t) entries;
61 trie_t *trie_new(void)
63 return p_new(trie_t, 1);
66 static inline void trie_cleanup_build_data(trie_t *trie)
68 array_wipe(trie->keys);
69 array_wipe(trie->keys_offset);
72 void trie_delete(trie_t **trie)
75 trie_cleanup_build_data(*trie);
77 array_wipe((*trie)->entries);
78 array_wipe((*trie)->c);
83 /** Check that the given entry is a prefix for the given key.
85 static inline bool trie_entry_c_match(const trie_t *trie,
86 const trie_entry_t *entry,
87 const char *key, int *pos)
89 const char *c = array_ptr(trie->c, entry->c_offset);
91 for (i = 0 ; i < entry->c_len ; ++i) {
105 static inline bool trie_entry_match(const trie_t *trie,
106 const trie_entry_t *entry, const char *key)
108 return !!(strcmp(array_ptr(trie->c, entry->c_offset), key) == 0);
111 static inline bool trie_entry_prefix(const trie_t *trie,
112 const trie_entry_t *entry, const char *key)
114 return !!(strncmp(array_ptr(trie->c, entry->c_offset), key, entry->c_len) == 0);
117 static inline bool trie_entry_is_leaf(const trie_entry_t *entry)
119 return entry->children_len == 0;
122 /** Lookup for a child of entry matching the given entry at the given pos.
123 * Only the first character of the children is taken into account in the
124 * lookup. The current entry is assumed to match the key.
126 static inline trie_entry_t* trie_entry_child(const trie_t *trie,
127 const trie_entry_t* entry,
130 int start = entry->children_offset;
131 int end = start + entry->children_len;
134 while (start < end) {
135 int mid = (start + end) / 2;
136 trie_entry_t* child = array_ptr(trie->entries, mid);
137 const char c2 = array_elt(trie->c, child->c_offset);
155 static inline uint32_t trie_entry_new(trie_t *trie)
157 const trie_entry_t e = TRIE_ENTRY_INIT;
158 array_add(trie->entries, e);
159 return trie->entries.len - 1;
162 static inline uint32_t trie_add_leaf(trie_t *trie, const char *key)
165 int len = m_strlen(key) + 1;
166 entry = array_ptr(trie->entries, trie_entry_new(trie));
167 entry->c_offset = trie->c.len;
169 array_append(trie->c, key, len);
170 return trie->entries.len - 1;
173 static inline void trie_entry_insert_child(trie_t *trie, trie_entry_t *entry,
176 if (entry->children_len == 0) {
177 entry->children_offset = pchild;
178 entry->children_len = 1;
180 if (entry->children_offset + entry->children_len != pchild) {
181 printf("Inserting child %d while offset is %d[%d]\n",
182 pchild, entry->children_offset, entry->children_len);
185 ++entry->children_len;
189 static inline void trie_entry_split(trie_t *trie, trie_entry_t *entry, uint16_t pos)
192 child = array_ptr(trie->entries, trie_entry_new(trie));
194 child->c_offset = entry->c_offset;
195 child->c_len = entry->c_len;
199 child->c_offset = entry->c_offset + pos;
200 child->c_len = entry->c_len - pos;
203 child->children_offset = entry->children_offset;
204 child->children_len = entry->children_len;
205 entry->children_offset = trie->entries.len - 1;
206 entry->children_len = 1;
209 void trie_insert(trie_t *trie, const char* key)
211 assert(trie->entries.len == 0 && "Trie already compiled");
213 int len = m_strlen(key) + 1;
214 array_add(trie->keys_offset, trie->keys.len);
215 array_append(trie->keys, key, len);
219 static inline void trie_compile_aux(trie_t *trie, uint32_t id,
220 uint32_t first_key, uint32_t last_key,
221 int offset, int initial_diff)
224 uint32_t fork_pos = 0;
227 for (int off_diff = initial_diff ; fork_pos == 0 ; ++off_diff, ++offset) {
228 current = array_elt(trie->keys, array_elt(trie->keys_offset, first_key) + offset);
229 for (uint32_t i = first_key + 1 ; i < last_key ; ++i) {
230 const char *str = array_ptr(trie->keys, array_elt(trie->keys_offset, i));
231 const char c = str[offset];
233 array_ensure_capacity_delta(trie->entries, 2);
235 trie_entry_split(trie, array_ptr(trie->entries, id), off_diff);
237 trie_entry_insert_child(trie, array_ptr(trie->entries, id),
238 trie_add_leaf(trie, str + offset));
239 forks[fork_pos++] = i;
243 if (fork_pos == 0 && current == '\0') {
247 forks[fork_pos] = last_key;
249 const uint8_t children_len = array_elt(trie->entries, id).children_len;
250 for (uint16_t i = 0 ; i < children_len ; ++i) {
251 int child = array_elt(trie->entries, id).children_offset + i;
252 if (forks[i] - 1 > first_key) {
253 trie_compile_aux(trie, child, first_key, forks[i], offset, 1);
255 first_key = forks[i];
259 void trie_compile(trie_t *trie, bool memlock)
261 assert(trie->entries.len == 0 && "Trie already compiled");
262 assert(trie->keys.len != 0 && "Trying to compile an empty trie");
264 # define QSORT_TYPE int
265 # define QSORT_BASE trie->keys_offset.data
266 # define QSORT_NELT trie->keys_offset.len
267 # define QSORT_LT(a,b) strcmp(trie->keys.data + *a, trie->keys.data + *b) < 0
271 array_ensure_capacity(trie->entries, trie->keys.len);
272 trie_compile_aux(trie, trie_add_leaf(trie, trie->keys.data),
273 0, trie->keys_offset.len, 0, 0);
274 trie_cleanup_build_data(trie);
275 array_adjust(trie->entries);
276 array_adjust(trie->c);
282 bool trie_lookup(const trie_t *trie, const char *key)
284 assert(trie->keys.len == 0L && "Can't lookup: trie not compiled");
285 if (trie->entries.len == 0) {
288 trie_entry_t *current = array_ptr(trie->entries, 0);
291 if (trie_entry_is_leaf(current)) {
292 return trie_entry_match(trie, current, key);
293 } else if (trie_entry_c_match(trie, current, key, &pos)) {
295 current = trie_entry_child(trie, current, key);
296 if (current == NULL) {
306 bool trie_prefix(const trie_t *trie, const char *key)
308 assert(trie->keys.len == 0L && "Can't lookup: trie not compiled");
309 if (trie->entries.len == 0) {
312 trie_entry_t *current = array_ptr(trie->entries, 0);
315 if (trie_entry_is_leaf(current)) {
316 return trie_entry_prefix(trie, current, key);
317 } else if (trie_entry_c_match(trie, current, key, &pos)) {
319 current = trie_entry_child(trie, current, key);
320 if (current == NULL) {
330 void trie_lock(trie_t *trie)
335 if (!array_lock(trie->entries)) {
338 if (!array_lock(trie->c)) {
341 if (mlock(trie, sizeof(trie_t)) != 0) {
348 void trie_unlock(trie_t *trie)
353 array_unlock(trie->entries);
354 array_unlock(trie->c);
355 munlock(trie, sizeof(trie_t));
356 trie->locked = false;
362 static inline void trie_entry_inspect(const trie_t *trie, bool show_content,
363 const trie_entry_t *entry, int level)
365 static int max_depth = 0;
366 static int leaves = 0;
367 static int depth_sum = 0;
369 if (trie_entry_is_leaf(entry)) {
370 if (level > max_depth) {
377 for (int i = 0 ; i < level ; ++i) {
380 if (entry->c_len == 0) {
381 fputs("(nil)", stdout);
383 const char *c = array_ptr(trie->c, entry->c_offset);
384 printf("(%d) ", entry->c_len);
385 for (int i = 0 ; i < entry->c_len ; ++i) {
389 fputs("\\0 ", stdout);
395 for (uint32_t i = entry->children_offset ;
396 i < entry->children_offset + entry->children_len ; ++i) {
397 trie_entry_inspect(trie, show_content, array_ptr(trie->entries, i), level + 1);
400 printf("Average char per node: %d\n", trie->c.len / trie->entries.len);
401 printf("Number of nodes: %d\n", trie->entries.len);
402 printf("Number of leaves: %d\n", leaves);
403 printf("Max depth: %d\n", max_depth);
404 printf("Average leaf depth: %d\n", depth_sum / leaves);
405 printf("Memory used: %d\n", (trie->entries.size * sizeof(trie_entry_t))
406 + (trie->c.size) + sizeof(trie_t));
410 void trie_inspect(const trie_t *trie, bool show_content)
412 trie_entry_inspect(trie, show_content, trie->entries.data, 0);