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

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Revision 1.21 - (hide annotations)
Thu Nov 20 01:02:15 2025 UTC (3 months, 3 weeks ago) by sysadm
Branch: MAIN
Changes since 1.20: +3 -9 lines
Content type: text/x-csrc
Refact set_xxxx_shm_readonly() with mprotect()

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 1.20 static char trie_node_shm_name[FILE_PATH_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 1.20 int trie_dict_cleanup(void)
121 sysadm 1.7 {
122     if (p_trie_node_pool == NULL)
123     {
124 sysadm 1.20 return -1;
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     return -2;
133 sysadm 1.7 }
134 sysadm 1.20
135     trie_node_shm_name[0] = '\0';
136    
137     return 0;
138 sysadm 1.7 }
139    
140 sysadm 1.20 int get_trie_dict_shm_readonly(void)
141 sysadm 1.7 {
142 sysadm 1.20 int fd;
143     struct stat sb;
144     size_t size;
145 sysadm 1.7 void *p_shm;
146    
147 sysadm 1.20 if ((fd = shm_open(trie_node_shm_name, O_RDONLY, 0600)) == -1)
148     {
149     log_error("shm_open(%s) error (%d)\n", trie_node_shm_name, errno);
150     return -2;
151     }
152    
153     if (fstat(fd, &sb) < 0)
154 sysadm 1.7 {
155 sysadm 1.20 log_error("fstat(fd) error (%d)\n", errno);
156     close(fd);
157     return -2;
158 sysadm 1.7 }
159    
160 sysadm 1.20 size = (size_t)sb.st_size;
161 sysadm 1.7
162 sysadm 1.20 p_shm = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0L);
163     if (p_shm == MAP_FAILED)
164 sysadm 1.7 {
165 sysadm 1.20 log_error("mmap() error (%d)\n", errno);
166     close(fd);
167     return -2;
168     }
169    
170     if (close(fd) < 0)
171     {
172     log_error("close(fd) error (%d)\n", errno);
173 sysadm 1.7 return -1;
174     }
175    
176 sysadm 1.20 if (p_trie_node_pool->shm_size != size)
177     {
178     log_error("Shared memory size mismatch (%ld != %ld)\n", p_trie_node_pool->shm_size, size);
179     munmap(p_shm, size);
180     return -3;
181     }
182    
183 sysadm 1.7 p_trie_node_pool = p_shm;
184 sysadm 1.20
185     return 0;
186     }
187    
188     int set_trie_dict_shm_readonly(void)
189     {
190 sysadm 1.21 if (p_trie_node_pool != NULL && mprotect(p_trie_node_pool, p_trie_node_pool->shm_size, PROT_READ) < 0)
191 sysadm 1.20 {
192 sysadm 1.21 log_error("mprotect() error (%d)\n", errno);
193     return -1;
194 sysadm 1.20 }
195 sysadm 1.7
196     return 0;
197     }
198    
199     int detach_trie_dict_shm(void)
200     {
201 sysadm 1.20 if (p_trie_node_pool != NULL && munmap(p_trie_node_pool, p_trie_node_pool->shm_size) < 0)
202 sysadm 1.7 {
203 sysadm 1.20 log_error("munmap() error (%d)\n", errno);
204 sysadm 1.7 return -1;
205     }
206 sysadm 1.8
207 sysadm 1.7 p_trie_node_pool = NULL;
208    
209     return 0;
210     }
211 sysadm 1.1
212     TRIE_NODE *trie_dict_create(void)
213     {
214 sysadm 1.7 TRIE_NODE *p_dict = NULL;
215    
216     if (p_trie_node_pool != NULL && p_trie_node_pool->p_node_free_list != NULL)
217     {
218     p_dict = p_trie_node_pool->p_node_free_list;
219     p_trie_node_pool->p_node_free_list = p_dict->p_nodes[0];
220 sysadm 1.1
221 sysadm 1.10 memset(p_dict, 0, sizeof(*p_dict));
222 sysadm 1.8
223     p_trie_node_pool->node_count++;
224     }
225     else if (p_trie_node_pool != NULL)
226     {
227     log_error("trie_dict_create() error: node depleted %d >= %d\n", p_trie_node_pool->node_count, p_trie_node_pool->node_count_limit);
228 sysadm 1.7 }
229 sysadm 1.1
230     return p_dict;
231     }
232    
233     void trie_dict_destroy(TRIE_NODE *p_dict)
234     {
235 sysadm 1.7 if (p_trie_node_pool == NULL || p_dict == NULL)
236 sysadm 1.1 {
237     return;
238     }
239    
240     for (int i = 0; i < TRIE_CHILDREN; i++)
241     {
242     if (p_dict->p_nodes[i] != NULL)
243     {
244     trie_dict_destroy(p_dict->p_nodes[i]);
245     }
246 sysadm 1.7 }
247 sysadm 1.3
248 sysadm 1.10 memset(p_dict, 0, sizeof(*p_dict));
249 sysadm 1.1
250 sysadm 1.7 p_dict->p_nodes[0] = p_trie_node_pool->p_node_free_list;
251     p_trie_node_pool->p_node_free_list = p_dict;
252 sysadm 1.8
253     p_trie_node_pool->node_count--;
254 sysadm 1.1 }
255    
256     int trie_dict_set(TRIE_NODE *p_dict, const char *key, int64_t value)
257     {
258     int offset;
259    
260 sysadm 1.5 if (p_dict == NULL)
261     {
262     return -1;
263     }
264    
265 sysadm 1.1 while (key != NULL && *key != '\0')
266     {
267 sysadm 1.6 offset = (256 + *key) % 256;
268 sysadm 1.3 if (offset < 0 || offset >= TRIE_CHILDREN) // incorrect key character
269     {
270     return -1;
271     }
272 sysadm 1.1
273     if (*(key + 1) == '\0')
274     {
275     if (p_dict->flags[offset] == 0 || p_dict->values[offset] != value)
276     {
277     p_dict->values[offset] = value;
278     p_dict->flags[offset] = 1;
279     return 1; // Set to new value
280     }
281     return 0; // Unchanged
282     }
283     else
284     {
285     if (p_dict->p_nodes[offset] == NULL)
286     {
287     if ((p_dict->p_nodes[offset] = trie_dict_create()) == NULL)
288     {
289     return -2; // OOM
290     }
291     }
292     p_dict = p_dict->p_nodes[offset];
293     key++;
294     }
295     }
296    
297     return -1; // NULL key
298     }
299    
300     int trie_dict_get(TRIE_NODE *p_dict, const char *key, int64_t *p_value)
301     {
302     int offset;
303    
304 sysadm 1.5 if (p_dict == NULL)
305     {
306     return -1;
307     }
308    
309 sysadm 1.1 while (key != NULL && *key != '\0')
310     {
311 sysadm 1.6 offset = (256 + *key) % 256;
312 sysadm 1.3 if (offset < 0 || offset >= TRIE_CHILDREN) // incorrect key character
313     {
314     return -1;
315     }
316 sysadm 1.1
317     if (*(key + 1) == '\0')
318     {
319     if (p_dict->flags[offset] != 0)
320     {
321     *p_value = p_dict->values[offset];
322     return 1; // Found
323     }
324     else
325     {
326     return 0; // Not exist
327     }
328     }
329     else if (p_dict->p_nodes[offset] == NULL)
330     {
331     return 0; // Not exist
332     }
333     else
334     {
335     p_dict = p_dict->p_nodes[offset];
336     key++;
337     }
338     }
339    
340     return -1; // NULL key
341     }
342    
343     int trie_dict_del(TRIE_NODE *p_dict, const char *key)
344     {
345     int offset;
346    
347 sysadm 1.5 if (p_dict == NULL)
348     {
349     return -1;
350     }
351    
352 sysadm 1.1 while (key != NULL && *key != '\0')
353     {
354 sysadm 1.6 offset = (256 + *key) % 256;
355 sysadm 1.3 if (offset < 0 || offset >= TRIE_CHILDREN) // incorrect key character
356     {
357     return -1;
358     }
359 sysadm 1.1
360     if (*(key + 1) == '\0')
361     {
362     if (p_dict->flags[offset] != 0)
363     {
364     p_dict->flags[offset] = 0;
365     p_dict->values[offset] = 0;
366     return 1; // Done
367     }
368     else
369     {
370     return 0; // Not exist
371     }
372     }
373     else if (p_dict->p_nodes[offset] == NULL)
374     {
375     return 0; // Not exist
376     }
377     else
378     {
379     p_dict = p_dict->p_nodes[offset];
380     key++;
381     }
382     }
383    
384     return -1; // NULL key
385     }
386 sysadm 1.2
387     static void _trie_dict_traverse(TRIE_NODE *p_dict, trie_dict_traverse_cb cb, char *key, int depth)
388     {
389     if (p_dict == NULL || depth >= TRIE_MAX_KEY_LEN)
390     {
391     return;
392     }
393    
394     for (int i = 0; i < TRIE_CHILDREN; i++)
395     {
396     if (p_dict->flags[i] != 0)
397     {
398 sysadm 1.5 key[depth] = (char)i;
399 sysadm 1.3 key[depth + 1] = '\0';
400 sysadm 1.2 (*cb)(key, p_dict->values[i]);
401     }
402    
403     if (p_dict->p_nodes[i] != NULL && depth + 1 < TRIE_MAX_KEY_LEN)
404     {
405 sysadm 1.5 key[depth] = (char)i;
406 sysadm 1.2 _trie_dict_traverse(p_dict->p_nodes[i], cb, key, depth + 1);
407     }
408 sysadm 1.5 }
409 sysadm 1.2 }
410    
411     void trie_dict_traverse(TRIE_NODE *p_dict, trie_dict_traverse_cb cb)
412     {
413     char key[TRIE_MAX_KEY_LEN + 1];
414 sysadm 1.5
415     if (p_dict == NULL)
416     {
417     return;
418     }
419 sysadm 1.2
420     _trie_dict_traverse(p_dict, cb, key, 0);
421     }
422 sysadm 1.8
423     int trie_dict_used_nodes(void)
424     {
425     return (p_trie_node_pool == NULL ? -1 : p_trie_node_pool->node_count);
426     }

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