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,
89 const char *c = array_ptr(trie->c, entry->c_offset);
91 for (i = 0 ; i < entry->c_len ; ++i) {
99 static inline bool trie_entry_match(const trie_t *trie,
100 const trie_entry_t *entry, const char *key)
102 return !!(strcmp(array_ptr(trie->c, entry->c_offset), key) == 0);
105 static inline bool trie_entry_prefix(const trie_t *trie,
106 const trie_entry_t *entry, const char *key)
108 int len = entry->c_len;
109 if (len > 0 && array_elt(trie->c, entry->c_offset + len - 1) == '\0') {
112 return !!(strncmp(array_ptr(trie->c, entry->c_offset), key, len) == 0);
115 static inline bool trie_entry_is_leaf(const trie_entry_t *entry)
117 return entry->children_len == 0;
120 /** Lookup for a child of entry matching the given entry at the given pos.
121 * Only the first character of the children is taken into account in the
122 * lookup. The current entry is assumed to match the key.
124 static inline const trie_entry_t* trie_entry_child(const trie_t *trie,
125 const trie_entry_t* entry,
128 uint32_t start = entry->children_offset;
129 uint32_t end = start + entry->children_len;
132 while (start < end) {
133 uint32_t mid = (start + end) >> 1;
134 const trie_entry_t* child = array_ptr(trie->entries, mid);
135 const char c2 = array_elt(trie->c, child->c_offset);
149 static inline uint32_t trie_entry_new(trie_t *trie)
151 const trie_entry_t e = TRIE_ENTRY_INIT;
152 array_add(trie->entries, e);
153 return trie->entries.len - 1;
156 static inline uint32_t trie_add_leaf(trie_t *trie, const char *key)
159 int len = m_strlen(key) + 1;
160 int id = trie_entry_new(trie);
161 entry = array_ptr(trie->entries, id);
162 entry->c_offset = trie->c.len;
164 #ifdef CHECK_INTEGRITY
165 for (int i = 0 ; i < len - 1 ; ++i) {
166 if (key[i] == '\0') {
167 printf("Found a '\\0' in the string of the leaf\n");
171 if (key[len - 1] != '\0') {
172 printf("Key does not end with a '\\0'");
176 array_append(trie->c, key, len);
177 return trie->entries.len - 1;
180 static inline void trie_entry_insert_child(trie_t *trie, uint32_t id, uint32_t pchild)
182 trie_entry_t *entry = array_ptr(trie->entries, id);
183 if (entry->children_len == 0) {
184 entry->children_offset = pchild;
185 entry->children_len = 1;
187 if (entry->children_offset + entry->children_len != pchild) {
188 printf("Inserting child %d while offset is %d[%d]\n",
189 pchild, entry->children_offset, entry->children_len);
192 ++entry->children_len;
196 static inline void trie_entry_split(trie_t *trie, uint32_t id, uint16_t pos)
200 child = array_ptr(trie->entries, trie_entry_new(trie));
201 entry = array_ptr(trie->entries, id);
203 child->c_offset = entry->c_offset;
204 child->c_len = entry->c_len;
208 assert(pos <= entry->c_len);
209 child->c_offset = entry->c_offset + pos;
210 child->c_len = entry->c_len - pos;
213 child->children_offset = entry->children_offset;
214 child->children_len = entry->children_len;
215 entry->children_offset = trie->entries.len - 1;
216 entry->children_len = 1;
219 void trie_insert(trie_t *trie, const char* key)
221 assert(trie->entries.len == 0 && "Trie already compiled");
223 int len = m_strlen(key) + 1;
224 array_add(trie->keys_offset, trie->keys.len);
225 array_append(trie->keys, key, len);
229 static inline void trie_compile_aux(trie_t *trie, uint32_t id,
230 uint32_t first_key, uint32_t last_key,
234 uint32_t fork_pos = 0;
237 #ifdef CHECK_INTEGRITY
238 assert(strcmp(array_ptr(trie->keys, array_elt(trie->keys_offset, first_key) + offset),
239 array_ptr(trie->c, array_elt(trie->entries, id).c_offset)) == 0);
242 for (int off_diff = 0 ; fork_pos == 0 ; ++off_diff, ++offset) {
243 current = array_elt(trie->keys, array_elt(trie->keys_offset, first_key) + offset);
244 for (uint32_t i = first_key + 1 ; i < last_key ; ++i) {
245 const char *str = array_ptr(trie->keys, array_elt(trie->keys_offset, i));
246 const char c = str[offset];
248 array_ensure_capacity_delta(trie->entries, 2);
250 trie_entry_split(trie, id, off_diff);
252 trie_entry_insert_child(trie, id, trie_add_leaf(trie, str + offset));
253 forks[fork_pos++] = i;
257 if (fork_pos == 0 && current == '\0') {
261 forks[fork_pos] = last_key;
263 const uint8_t children_len = array_elt(trie->entries, id).children_len;
264 for (uint16_t i = 0 ; i < children_len ; ++i) {
265 int child = array_elt(trie->entries, id).children_offset + i;
266 if (forks[i] - 1 > first_key) {
267 trie_compile_aux(trie, child, first_key, forks[i], offset - 1);
269 first_key = forks[i];
273 void trie_compile(trie_t *trie, bool memlock)
275 assert(trie->entries.len == 0 && "Trie already compiled");
276 assert(trie->keys.len != 0 && "Trying to compile an empty trie");
278 # define QSORT_TYPE int
279 # define QSORT_BASE trie->keys_offset.data
280 # define QSORT_NELT trie->keys_offset.len
281 # define QSORT_LT(a,b) strcmp(trie->keys.data + *a, trie->keys.data + *b) < 0
285 array_ensure_capacity(trie->entries, trie->keys_offset.len);
286 trie_compile_aux(trie, trie_add_leaf(trie, array_ptr(trie->keys, array_elt(trie->keys_offset, 0))),
287 0, trie->keys_offset.len, 0);
288 trie_cleanup_build_data(trie);
289 array_adjust(trie->entries);
290 array_adjust(trie->c);
296 bool trie_lookup(const trie_t *trie, const char *key)
298 assert(trie->keys.len == 0L && "Can't lookup: trie not compiled");
299 if (trie->entries.len == 0) {
302 const trie_entry_t *current = array_ptr(trie->entries, 0);
304 if (trie_entry_is_leaf(current)) {
305 return trie_entry_match(trie, current, key);
306 } else if (trie_entry_c_match(trie, current, key)) {
307 key += current->c_len;
308 current = trie_entry_child(trie, current, key);
309 if (current == NULL) {
319 bool trie_prefix(const trie_t *trie, const char *key)
321 assert(trie->keys.len == 0L && "Can't lookup: trie not compiled");
322 if (trie->entries.len == 0) {
325 const trie_entry_t *current = array_ptr(trie->entries, 0);
327 if (trie_entry_is_leaf(current)) {
328 return trie_entry_prefix(trie, current, key);
329 } else if (trie_entry_c_match(trie, current, key)) {
330 key += current->c_len;
331 current = trie_entry_child(trie, current, key);
332 if (current == NULL) {
342 void trie_lock(trie_t *trie)
347 if (!array_lock(trie->entries)) {
350 if (!array_lock(trie->c)) {
353 if (mlock(trie, sizeof(trie_t)) != 0) {
360 void trie_unlock(trie_t *trie)
365 array_unlock(trie->entries);
366 array_unlock(trie->c);
367 munlock(trie, sizeof(trie_t));
368 trie->locked = false;
374 static inline void trie_entry_inspect(const trie_t *trie, bool show_content,
375 const trie_entry_t *entry, int level)
377 static int max_depth = 0;
378 static int leaves = 0;
379 static int depth_sum = 0;
381 if (entry == array_ptr(trie->entries, 0)) {
386 if (trie_entry_is_leaf(entry)) {
387 if (level > max_depth) {
394 for (int i = 0 ; i < level ; ++i) {
397 if (entry->c_len == 0) {
398 fputs("(0)", stdout);
400 const char *c = array_ptr(trie->c, entry->c_offset);
401 printf("(%d) ", entry->c_len);
402 for (int i = 0 ; i < entry->c_len ; ++i) {
406 fputs("\\0 ", stdout);
412 for (uint32_t i = entry->children_offset ;
413 i < entry->children_offset + entry->children_len ; ++i) {
414 trie_entry_inspect(trie, show_content, array_ptr(trie->entries, i), level + 1);
417 printf("Average char per node: %d\n", trie->c.len / trie->entries.len);
418 printf("Number of nodes: %d\n", trie->entries.len);
419 printf("Number of leaves: %d\n", leaves);
420 printf("Max depth: %d\n", max_depth);
421 printf("Average leaf depth: %d\n", depth_sum / leaves);
422 printf("Memory used: %zd\n", (trie->entries.size * sizeof(trie_entry_t))
423 + (trie->c.size) + sizeof(trie_t));
427 void trie_inspect(const trie_t *trie, bool show_content)
429 trie_entry_inspect(trie, show_content, trie->entries.data, 0);