/[LeafOK_CVS]/lbbs/src/trie_dict.c
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Annotation of /lbbs/src/trie_dict.c

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Revision 1.23 - (hide annotations)
Thu Nov 20 03:22:35 2025 UTC (3 months, 3 weeks ago) by sysadm
Branch: MAIN
Changes since 1.22: +3 -5 lines
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1 sysadm 1.13 /* SPDX-License-Identifier: GPL-3.0-or-later */
2     /*
3     * trie_dict
4     * - trie-tree based dict feature
5     *
6 sysadm 1.15 * Copyright (C) 2004-2025 Leaflet <leaflet@leafok.com>
7 sysadm 1.13 */
8 sysadm 1.1
9 sysadm 1.16 #ifdef HAVE_CONFIG_H
10     #include "config.h"
11     #endif
12    
13 sysadm 1.20 #include "common.h"
14 sysadm 1.11 #include "log.h"
15 sysadm 1.1 #include "trie_dict.h"
16 sysadm 1.7 #include <errno.h>
17 sysadm 1.20 #include <fcntl.h>
18 sysadm 1.10 #include <stdio.h>
19 sysadm 1.1 #include <stdlib.h>
20 sysadm 1.10 #include <string.h>
21 sysadm 1.7 #include <time.h>
22     #include <unistd.h>
23 sysadm 1.20 #include <sys/mman.h>
24     #include <sys/stat.h>
25 sysadm 1.7
26     struct trie_node_pool_t
27     {
28 sysadm 1.20 size_t shm_size;
29 sysadm 1.8 int node_count_limit;
30     int node_count;
31 sysadm 1.7 TRIE_NODE *p_node_free_list;
32     };
33     typedef struct trie_node_pool_t TRIE_NODE_POOL;
34    
35 sysadm 1.23 static char trie_node_shm_name[FILE_NAME_LEN];
36 sysadm 1.7 static TRIE_NODE_POOL *p_trie_node_pool;
37    
38 sysadm 1.8 int trie_dict_init(const char *filename, int node_count_limit)
39 sysadm 1.7 {
40 sysadm 1.20 char filepath[FILE_PATH_LEN];
41     int fd;
42 sysadm 1.7 size_t size;
43     void *p_shm;
44 sysadm 1.8 TRIE_NODE *p_trie_nodes;
45 sysadm 1.7 int i;
46    
47 sysadm 1.20 if (filename == NULL)
48     {
49     log_error("NULL pointer error\n");
50     return -1;
51     }
52    
53 sysadm 1.7 if (p_trie_node_pool != NULL)
54     {
55     log_error("trie_dict_pool already initialized\n");
56     return -1;
57     }
58    
59 sysadm 1.8 if (node_count_limit <= 0 || node_count_limit > TRIE_NODE_PER_POOL)
60     {
61     log_error("trie_dict_init(%d) error: invalid node_count_limit\n", node_count_limit);
62     return -1;
63     }
64    
65 sysadm 1.7 // Allocate shared memory
66 sysadm 1.20 size = sizeof(TRIE_NODE_POOL) + sizeof(TRIE_NODE) * (size_t)node_count_limit;
67    
68     strncpy(filepath, filename, sizeof(filepath) - 1);
69     filepath[sizeof(filepath) - 1] = '\0';
70     snprintf(trie_node_shm_name, sizeof(trie_node_shm_name), "/TRIE_DICT_SHM_%s", basename(filepath));
71    
72     if (shm_unlink(trie_node_shm_name) == -1 && errno != ENOENT)
73 sysadm 1.7 {
74 sysadm 1.20 log_error("shm_unlink(%s) error (%d)\n", trie_node_shm_name, errno);
75 sysadm 1.7 return -2;
76     }
77    
78 sysadm 1.20 if ((fd = shm_open(trie_node_shm_name, O_CREAT | O_EXCL | O_RDWR, 0600)) == -1)
79     {
80     log_error("shm_open(%s) error (%d)\n", trie_node_shm_name, errno);
81     return -2;
82     }
83     if (ftruncate(fd, (off_t)size) == -1)
84     {
85     log_error("ftruncate(size=%d) error (%d)\n", size, errno);
86     close(fd);
87     return -2;
88     }
89    
90     p_shm = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0L);
91     if (p_shm == MAP_FAILED)
92 sysadm 1.7 {
93 sysadm 1.20 log_error("mmap() error (%d)\n", errno);
94     close(fd);
95     return -2;
96 sysadm 1.7 }
97 sysadm 1.20
98     if (close(fd) < 0)
99 sysadm 1.7 {
100 sysadm 1.20 log_error("close(fd) error (%d)\n", errno);
101     return -1;
102 sysadm 1.7 }
103    
104     p_trie_node_pool = p_shm;
105 sysadm 1.20 p_trie_node_pool->shm_size = size;
106 sysadm 1.8 p_trie_node_pool->node_count_limit = node_count_limit;
107 sysadm 1.7 p_trie_node_pool->node_count = 0;
108    
109 sysadm 1.12 p_trie_nodes = (TRIE_NODE *)((char *)p_shm + sizeof(TRIE_NODE_POOL));
110 sysadm 1.8 p_trie_node_pool->p_node_free_list = &(p_trie_nodes[0]);
111     for (i = 0; i < node_count_limit - 1; i++)
112 sysadm 1.7 {
113 sysadm 1.8 p_trie_nodes[i].p_nodes[0] = &(p_trie_nodes[i + 1]);
114 sysadm 1.7 }
115 sysadm 1.8 p_trie_nodes[node_count_limit - 1].p_nodes[0] = NULL;
116 sysadm 1.7
117     return 0;
118     }
119    
120 sysadm 1.23 void trie_dict_cleanup(void)
121 sysadm 1.7 {
122     if (p_trie_node_pool == NULL)
123     {
124 sysadm 1.23 return;
125 sysadm 1.7 }
126    
127     detach_trie_dict_shm();
128    
129 sysadm 1.20 if (shm_unlink(trie_node_shm_name) == -1 && errno != ENOENT)
130 sysadm 1.7 {
131 sysadm 1.20 log_error("shm_unlink(%s) error (%d)\n", trie_node_shm_name, errno);
132 sysadm 1.7 }
133 sysadm 1.20
134     trie_node_shm_name[0] = '\0';
135 sysadm 1.7 }
136    
137 sysadm 1.20 int get_trie_dict_shm_readonly(void)
138 sysadm 1.7 {
139 sysadm 1.20 int fd;
140     struct stat sb;
141     size_t size;
142 sysadm 1.7 void *p_shm;
143    
144 sysadm 1.20 if ((fd = shm_open(trie_node_shm_name, O_RDONLY, 0600)) == -1)
145     {
146     log_error("shm_open(%s) error (%d)\n", trie_node_shm_name, errno);
147     return -2;
148     }
149    
150     if (fstat(fd, &sb) < 0)
151 sysadm 1.7 {
152 sysadm 1.20 log_error("fstat(fd) error (%d)\n", errno);
153     close(fd);
154     return -2;
155 sysadm 1.7 }
156    
157 sysadm 1.20 size = (size_t)sb.st_size;
158 sysadm 1.7
159 sysadm 1.20 p_shm = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0L);
160     if (p_shm == MAP_FAILED)
161 sysadm 1.7 {
162 sysadm 1.20 log_error("mmap() error (%d)\n", errno);
163     close(fd);
164     return -2;
165     }
166    
167     if (close(fd) < 0)
168     {
169     log_error("close(fd) error (%d)\n", errno);
170 sysadm 1.7 return -1;
171     }
172    
173 sysadm 1.20 if (p_trie_node_pool->shm_size != size)
174     {
175     log_error("Shared memory size mismatch (%ld != %ld)\n", p_trie_node_pool->shm_size, size);
176     munmap(p_shm, size);
177     return -3;
178     }
179    
180 sysadm 1.7 p_trie_node_pool = p_shm;
181 sysadm 1.20
182     return 0;
183     }
184    
185     int set_trie_dict_shm_readonly(void)
186     {
187 sysadm 1.21 if (p_trie_node_pool != NULL && mprotect(p_trie_node_pool, p_trie_node_pool->shm_size, PROT_READ) < 0)
188 sysadm 1.20 {
189 sysadm 1.21 log_error("mprotect() error (%d)\n", errno);
190     return -1;
191 sysadm 1.20 }
192 sysadm 1.7
193     return 0;
194     }
195    
196     int detach_trie_dict_shm(void)
197     {
198 sysadm 1.20 if (p_trie_node_pool != NULL && munmap(p_trie_node_pool, p_trie_node_pool->shm_size) < 0)
199 sysadm 1.7 {
200 sysadm 1.20 log_error("munmap() error (%d)\n", errno);
201 sysadm 1.7 return -1;
202     }
203 sysadm 1.8
204 sysadm 1.7 p_trie_node_pool = NULL;
205    
206     return 0;
207     }
208 sysadm 1.1
209     TRIE_NODE *trie_dict_create(void)
210     {
211 sysadm 1.7 TRIE_NODE *p_dict = NULL;
212    
213     if (p_trie_node_pool != NULL && p_trie_node_pool->p_node_free_list != NULL)
214     {
215     p_dict = p_trie_node_pool->p_node_free_list;
216     p_trie_node_pool->p_node_free_list = p_dict->p_nodes[0];
217 sysadm 1.1
218 sysadm 1.10 memset(p_dict, 0, sizeof(*p_dict));
219 sysadm 1.8
220     p_trie_node_pool->node_count++;
221     }
222     else if (p_trie_node_pool != NULL)
223     {
224     log_error("trie_dict_create() error: node depleted %d >= %d\n", p_trie_node_pool->node_count, p_trie_node_pool->node_count_limit);
225 sysadm 1.7 }
226 sysadm 1.1
227     return p_dict;
228     }
229    
230     void trie_dict_destroy(TRIE_NODE *p_dict)
231     {
232 sysadm 1.7 if (p_trie_node_pool == NULL || p_dict == NULL)
233 sysadm 1.1 {
234     return;
235     }
236    
237     for (int i = 0; i < TRIE_CHILDREN; i++)
238     {
239     if (p_dict->p_nodes[i] != NULL)
240     {
241     trie_dict_destroy(p_dict->p_nodes[i]);
242     }
243 sysadm 1.7 }
244 sysadm 1.3
245 sysadm 1.10 memset(p_dict, 0, sizeof(*p_dict));
246 sysadm 1.1
247 sysadm 1.7 p_dict->p_nodes[0] = p_trie_node_pool->p_node_free_list;
248     p_trie_node_pool->p_node_free_list = p_dict;
249 sysadm 1.8
250     p_trie_node_pool->node_count--;
251 sysadm 1.1 }
252    
253     int trie_dict_set(TRIE_NODE *p_dict, const char *key, int64_t value)
254     {
255     int offset;
256    
257 sysadm 1.5 if (p_dict == NULL)
258     {
259     return -1;
260     }
261    
262 sysadm 1.1 while (key != NULL && *key != '\0')
263     {
264 sysadm 1.6 offset = (256 + *key) % 256;
265 sysadm 1.3 if (offset < 0 || offset >= TRIE_CHILDREN) // incorrect key character
266     {
267     return -1;
268     }
269 sysadm 1.1
270     if (*(key + 1) == '\0')
271     {
272     if (p_dict->flags[offset] == 0 || p_dict->values[offset] != value)
273     {
274     p_dict->values[offset] = value;
275     p_dict->flags[offset] = 1;
276     return 1; // Set to new value
277     }
278     return 0; // Unchanged
279     }
280     else
281     {
282     if (p_dict->p_nodes[offset] == NULL)
283     {
284     if ((p_dict->p_nodes[offset] = trie_dict_create()) == NULL)
285     {
286     return -2; // OOM
287     }
288     }
289     p_dict = p_dict->p_nodes[offset];
290     key++;
291     }
292     }
293    
294     return -1; // NULL key
295     }
296    
297     int trie_dict_get(TRIE_NODE *p_dict, const char *key, int64_t *p_value)
298     {
299     int offset;
300    
301 sysadm 1.5 if (p_dict == NULL)
302     {
303     return -1;
304     }
305    
306 sysadm 1.1 while (key != NULL && *key != '\0')
307     {
308 sysadm 1.6 offset = (256 + *key) % 256;
309 sysadm 1.3 if (offset < 0 || offset >= TRIE_CHILDREN) // incorrect key character
310     {
311     return -1;
312     }
313 sysadm 1.1
314     if (*(key + 1) == '\0')
315     {
316     if (p_dict->flags[offset] != 0)
317     {
318     *p_value = p_dict->values[offset];
319     return 1; // Found
320     }
321     else
322     {
323     return 0; // Not exist
324     }
325     }
326     else if (p_dict->p_nodes[offset] == NULL)
327     {
328     return 0; // Not exist
329     }
330     else
331     {
332     p_dict = p_dict->p_nodes[offset];
333     key++;
334     }
335     }
336    
337     return -1; // NULL key
338     }
339    
340     int trie_dict_del(TRIE_NODE *p_dict, const char *key)
341     {
342     int offset;
343    
344 sysadm 1.5 if (p_dict == NULL)
345     {
346     return -1;
347     }
348    
349 sysadm 1.1 while (key != NULL && *key != '\0')
350     {
351 sysadm 1.6 offset = (256 + *key) % 256;
352 sysadm 1.3 if (offset < 0 || offset >= TRIE_CHILDREN) // incorrect key character
353     {
354     return -1;
355     }
356 sysadm 1.1
357     if (*(key + 1) == '\0')
358     {
359     if (p_dict->flags[offset] != 0)
360     {
361     p_dict->flags[offset] = 0;
362     p_dict->values[offset] = 0;
363     return 1; // Done
364     }
365     else
366     {
367     return 0; // Not exist
368     }
369     }
370     else if (p_dict->p_nodes[offset] == NULL)
371     {
372     return 0; // Not exist
373     }
374     else
375     {
376     p_dict = p_dict->p_nodes[offset];
377     key++;
378     }
379     }
380    
381     return -1; // NULL key
382     }
383 sysadm 1.2
384     static void _trie_dict_traverse(TRIE_NODE *p_dict, trie_dict_traverse_cb cb, char *key, int depth)
385     {
386     if (p_dict == NULL || depth >= TRIE_MAX_KEY_LEN)
387     {
388     return;
389     }
390    
391     for (int i = 0; i < TRIE_CHILDREN; i++)
392     {
393     if (p_dict->flags[i] != 0)
394     {
395 sysadm 1.5 key[depth] = (char)i;
396 sysadm 1.3 key[depth + 1] = '\0';
397 sysadm 1.2 (*cb)(key, p_dict->values[i]);
398     }
399    
400     if (p_dict->p_nodes[i] != NULL && depth + 1 < TRIE_MAX_KEY_LEN)
401     {
402 sysadm 1.5 key[depth] = (char)i;
403 sysadm 1.2 _trie_dict_traverse(p_dict->p_nodes[i], cb, key, depth + 1);
404     }
405 sysadm 1.5 }
406 sysadm 1.2 }
407    
408     void trie_dict_traverse(TRIE_NODE *p_dict, trie_dict_traverse_cb cb)
409     {
410     char key[TRIE_MAX_KEY_LEN + 1];
411 sysadm 1.5
412     if (p_dict == NULL)
413     {
414     return;
415     }
416 sysadm 1.2
417     _trie_dict_traverse(p_dict, cb, key, 0);
418     }
419 sysadm 1.8
420     int trie_dict_used_nodes(void)
421     {
422     return (p_trie_node_pool == NULL ? -1 : p_trie_node_pool->node_count);
423     }

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