lbbs/src/trie_dict.c

/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
 * trie_dict
 *   - trie-tree based dict feature
 *
 * Copyright (C) 2004-2026  Leaflet <leaflet@leafok.com>
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "common.h"
#include "log.h"
#include "trie_dict.h"
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/stat.h>

struct trie_node_pool_t
{
        size_t shm_size;
        int node_count_limit;
        int node_count;
        TRIE_NODE *p_node_free_list;
};
typedef struct trie_node_pool_t TRIE_NODE_POOL;

static char trie_node_shm_name[FILE_NAME_LEN];
static TRIE_NODE_POOL *p_trie_node_pool;

int trie_dict_init(const char *filename, int node_count_limit)
{
        char filepath[FILE_PATH_LEN];
        int fd;
        size_t size;
        void *p_shm;
        TRIE_NODE *p_trie_nodes;
        int i;

        if (filename == NULL)
        {
                log_error("NULL pointer error");
                return -1;
        }

        if (p_trie_node_pool != NULL)
        {
                log_error("trie_dict_pool already initialized");
                return -1;
        }

        if (node_count_limit <= 0 || node_count_limit > TRIE_NODE_PER_POOL)
        {
                log_error("trie_dict_init(%d) error: invalid node_count_limit", node_count_limit);
                return -1;
        }

        // Allocate shared memory
        size = sizeof(TRIE_NODE_POOL) + sizeof(TRIE_NODE) * (size_t)node_count_limit;

        strncpy(filepath, filename, sizeof(filepath) - 1);
        filepath[sizeof(filepath) - 1] = '\0';
        snprintf(trie_node_shm_name, sizeof(trie_node_shm_name), "/TRIE_DICT_SHM_%s", basename(filepath));

        if (shm_unlink(trie_node_shm_name) == -1 && errno != ENOENT)
        {
                log_error("shm_unlink(%s) error (%d)", trie_node_shm_name, errno);
                return -2;
        }

        if ((fd = shm_open(trie_node_shm_name, O_CREAT | O_EXCL | O_RDWR, 0600)) == -1)
        {
                log_error("shm_open(%s) error (%d)", trie_node_shm_name, errno);
                return -2;
        }
        if (ftruncate(fd, (off_t)size) == -1)
        {
                log_error("ftruncate(size=%d) error (%d)", size, errno);
                close(fd);
                return -2;
        }

        p_shm = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0L);
        if (p_shm == MAP_FAILED)
        {
                log_error("mmap() error (%d)", errno);
                close(fd);
                return -2;
        }

        if (close(fd) < 0)
        {
                log_error("close(fd) error (%d)", errno);
                return -1;
        }

        p_trie_node_pool = p_shm;
        p_trie_node_pool->shm_size = size;
        p_trie_node_pool->node_count_limit = node_count_limit;
        p_trie_node_pool->node_count = 0;

        p_trie_nodes = (TRIE_NODE *)((char *)p_shm + sizeof(TRIE_NODE_POOL));
        p_trie_node_pool->p_node_free_list = &(p_trie_nodes[0]);
        for (i = 0; i < node_count_limit - 1; i++)
        {
                p_trie_nodes[i].p_nodes[0] = &(p_trie_nodes[i + 1]);
        }
        p_trie_nodes[node_count_limit - 1].p_nodes[0] = NULL;

        return 0;
}

void trie_dict_cleanup(void)
{
        if (p_trie_node_pool == NULL)
        {
                return;
        }

        detach_trie_dict_shm();

        if (shm_unlink(trie_node_shm_name) == -1 && errno != ENOENT)
        {
                log_error("shm_unlink(%s) error (%d)", trie_node_shm_name, errno);
        }

        trie_node_shm_name[0] = '\0';
}

int set_trie_dict_shm_readonly(void)
{
        if (p_trie_node_pool != NULL && mprotect(p_trie_node_pool, p_trie_node_pool->shm_size, PROT_READ) < 0)
        {
                log_error("mprotect() error (%d)", errno);
                return -1;
        }

        return 0;
}

int detach_trie_dict_shm(void)
{
        if (p_trie_node_pool != NULL && munmap(p_trie_node_pool, p_trie_node_pool->shm_size) < 0)
        {
                log_error("munmap() error (%d)", errno);
                return -1;
        }

        p_trie_node_pool = NULL;

        return 0;
}

TRIE_NODE *trie_dict_create(void)
{
        TRIE_NODE *p_dict = NULL;

        if (p_trie_node_pool != NULL && p_trie_node_pool->p_node_free_list != NULL)
        {
                p_dict = p_trie_node_pool->p_node_free_list;
                p_trie_node_pool->p_node_free_list = p_dict->p_nodes[0];

                memset(p_dict, 0, sizeof(*p_dict));

                p_trie_node_pool->node_count++;
        }
        else if (p_trie_node_pool != NULL)
        {
                log_error("trie_dict_create() error: node depleted %d >= %d", p_trie_node_pool->node_count, p_trie_node_pool->node_count_limit);
        }

        return p_dict;
}

void trie_dict_destroy(TRIE_NODE *p_dict)
{
        if (p_trie_node_pool == NULL || p_dict == NULL)
        {
                return;
        }

        for (int i = 0; i < TRIE_CHILDREN; i++)
        {
                if (p_dict->p_nodes[i] != NULL)
                {
                        trie_dict_destroy(p_dict->p_nodes[i]);
                }
        }

        memset(p_dict, 0, sizeof(*p_dict));

        p_dict->p_nodes[0] = p_trie_node_pool->p_node_free_list;
        p_trie_node_pool->p_node_free_list = p_dict;

        p_trie_node_pool->node_count--;
}

int trie_dict_set(TRIE_NODE *p_dict, const char *key, int64_t value)
{
        int offset;

        if (p_dict == NULL)
        {
                return -1;
        }

        while (key != NULL && *key != '\0')
        {
                offset = (unsigned char)(*key);
                if (offset < 0 || offset >= TRIE_CHILDREN) // incorrect key character
                {
                        return -1;
                }

                if (*(key + 1) == '\0')
                {
                        if (p_dict->flags[offset] == 0 || p_dict->values[offset] != value)
                        {
                                p_dict->values[offset] = value;
                                p_dict->flags[offset] = 1;
                                return 1; // Set to new value
                        }
                        return 0; // Unchanged
                }
                else
                {
                        if (p_dict->p_nodes[offset] == NULL)
                        {
                                if ((p_dict->p_nodes[offset] = trie_dict_create()) == NULL)
                                {
                                        return -2; // OOM
                                }
                        }
                        p_dict = p_dict->p_nodes[offset];
                        key++;
                }
        }

        return -1; // NULL key
}

int trie_dict_get(TRIE_NODE *p_dict, const char *key, int64_t *p_value)
{
        int offset;

        if (p_dict == NULL)
        {
                return -1;
        }

        while (key != NULL && *key != '\0')
        {
                offset = (unsigned char)(*key);
                if (offset < 0 || offset >= TRIE_CHILDREN) // incorrect key character
                {
                        return -1;
                }

                if (*(key + 1) == '\0')
                {
                        if (p_dict->flags[offset] != 0)
                        {
                                *p_value = p_dict->values[offset];
                                return 1; // Found
                        }
                        else
                        {
                                return 0; // Not exist
                        }
                }
                else if (p_dict->p_nodes[offset] == NULL)
                {
                        return 0; // Not exist
                }
                else
                {
                        p_dict = p_dict->p_nodes[offset];
                        key++;
                }
        }

        return -1; // NULL key
}

int trie_dict_del(TRIE_NODE *p_dict, const char *key)
{
        int offset;

        if (p_dict == NULL)
        {
                return -1;
        }

        while (key != NULL && *key != '\0')
        {
                offset = (unsigned char)(*key);
                if (offset < 0 || offset >= TRIE_CHILDREN) // incorrect key character
                {
                        return -1;
                }

                if (*(key + 1) == '\0')
                {
                        if (p_dict->flags[offset] != 0)
                        {
                                p_dict->flags[offset] = 0;
                                p_dict->values[offset] = 0;
                                return 1; // Done
                        }
                        else
                        {
                                return 0; // Not exist
                        }
                }
                else if (p_dict->p_nodes[offset] == NULL)
                {
                        return 0; // Not exist
                }
                else
                {
                        p_dict = p_dict->p_nodes[offset];
                        key++;
                }
        }

        return -1; // NULL key
}

static void _trie_dict_traverse(TRIE_NODE *p_dict, trie_dict_traverse_cb cb, char *key, int depth)
{
        if (p_dict == NULL || depth >= TRIE_MAX_KEY_LEN)
        {
                return;
        }

        for (int i = 0; i < TRIE_CHILDREN; i++)
        {
                if (p_dict->flags[i] != 0)
                {
                        key[depth] = (char)i;
                        key[depth + 1] = '\0';
                        (*cb)(key, p_dict->values[i]);
                }

                if (p_dict->p_nodes[i] != NULL && depth + 1 < TRIE_MAX_KEY_LEN)
                {
                        key[depth] = (char)i;
                        _trie_dict_traverse(p_dict->p_nodes[i], cb, key, depth + 1);
                }
        }
}

void trie_dict_traverse(TRIE_NODE *p_dict, trie_dict_traverse_cb cb)
{
        char key[TRIE_MAX_KEY_LEN + 1];

        if (p_dict == NULL)
        {
                return;
        }

        _trie_dict_traverse(p_dict, cb, key, 0);
}

int trie_dict_used_nodes(void)
{
        return (p_trie_node_pool == NULL ? -1 : p_trie_node_pool->node_count);
}
1	/* SPDX-License-Identifier: GPL-3.0-or-later */
2	/*
3	* trie_dict
4	* - trie-tree based dict feature
5	*
6	* Copyright (C) 2004-2026 Leaflet <leaflet@leafok.com>
7	*/
8
9	#ifdef HAVE_CONFIG_H
10	#include "config.h"
11	#endif
12
13	#include "common.h"
14	#include "log.h"
15	#include "trie_dict.h"
16	#include <errno.h>
17	#include <fcntl.h>
18	#include <stdio.h>
19	#include <stdlib.h>
20	#include <string.h>
21	#include <time.h>
22	#include <unistd.h>
23	#include <sys/mman.h>
24	#include <sys/stat.h>
25
26	struct trie_node_pool_t
27	{
28	size_t shm_size;
29	int node_count_limit;
30	int node_count;
31	TRIE_NODE *p_node_free_list;
32	};
33	typedef struct trie_node_pool_t TRIE_NODE_POOL;
34
35	static char trie_node_shm_name[FILE_NAME_LEN];
36	static TRIE_NODE_POOL *p_trie_node_pool;
37
38	int trie_dict_init(const char *filename, int node_count_limit)
39	{
40	char filepath[FILE_PATH_LEN];
41	int fd;
42	size_t size;
43	void *p_shm;
44	TRIE_NODE *p_trie_nodes;
45	int i;
46
47	if (filename == NULL)
48	{
49	log_error("NULL pointer error");
50	return -1;
51	}
52
53	if (p_trie_node_pool != NULL)
54	{
55	log_error("trie_dict_pool already initialized");
56	return -1;
57	}
58
59	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", node_count_limit);
62	return -1;
63	}
64
65	// Allocate shared memory
66	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	{
74	log_error("shm_unlink(%s) error (%d)", trie_node_shm_name, errno);
75	return -2;
76	}
77
78	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)", 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)", 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	{
93	log_error("mmap() error (%d)", errno);
94	close(fd);
95	return -2;
96	}
97
98	if (close(fd) < 0)
99	{
100	log_error("close(fd) error (%d)", errno);
101	return -1;
102	}
103
104	p_trie_node_pool = p_shm;
105	p_trie_node_pool->shm_size = size;
106	p_trie_node_pool->node_count_limit = node_count_limit;
107	p_trie_node_pool->node_count = 0;
108
109	p_trie_nodes = (TRIE_NODE )((char )p_shm + sizeof(TRIE_NODE_POOL));
110	p_trie_node_pool->p_node_free_list = &(p_trie_nodes[0]);
111	for (i = 0; i < node_count_limit - 1; i++)
112	{
113	p_trie_nodes[i].p_nodes[0] = &(p_trie_nodes[i + 1]);
114	}
115	p_trie_nodes[node_count_limit - 1].p_nodes[0] = NULL;
116
117	return 0;
118	}
119
120	void trie_dict_cleanup(void)
121	{
122	if (p_trie_node_pool == NULL)
123	{
124	return;
125	}
126
127	detach_trie_dict_shm();
128
129	if (shm_unlink(trie_node_shm_name) == -1 && errno != ENOENT)
130	{
131	log_error("shm_unlink(%s) error (%d)", trie_node_shm_name, errno);
132	}
133
134	trie_node_shm_name[0] = '\0';
135	}
136
137	int set_trie_dict_shm_readonly(void)
138	{
139	if (p_trie_node_pool != NULL && mprotect(p_trie_node_pool, p_trie_node_pool->shm_size, PROT_READ) < 0)
140	{
141	log_error("mprotect() error (%d)", errno);
142	return -1;
143	}
144
145	return 0;
146	}
147
148	int detach_trie_dict_shm(void)
149	{
150	if (p_trie_node_pool != NULL && munmap(p_trie_node_pool, p_trie_node_pool->shm_size) < 0)
151	{
152	log_error("munmap() error (%d)", errno);
153	return -1;
154	}
155
156	p_trie_node_pool = NULL;
157
158	return 0;
159	}
160
161	TRIE_NODE *trie_dict_create(void)
162	{
163	TRIE_NODE *p_dict = NULL;
164
165	if (p_trie_node_pool != NULL && p_trie_node_pool->p_node_free_list != NULL)
166	{
167	p_dict = p_trie_node_pool->p_node_free_list;
168	p_trie_node_pool->p_node_free_list = p_dict->p_nodes[0];
169
170	memset(p_dict, 0, sizeof(*p_dict));
171
172	p_trie_node_pool->node_count++;
173	}
174	else if (p_trie_node_pool != NULL)
175	{
176	log_error("trie_dict_create() error: node depleted %d >= %d", p_trie_node_pool->node_count, p_trie_node_pool->node_count_limit);
177	}
178
179	return p_dict;
180	}
181
182	void trie_dict_destroy(TRIE_NODE *p_dict)
183	{
184	if (p_trie_node_pool == NULL \|\| p_dict == NULL)
185	{
186	return;
187	}
188
189	for (int i = 0; i < TRIE_CHILDREN; i++)
190	{
191	if (p_dict->p_nodes[i] != NULL)
192	{
193	trie_dict_destroy(p_dict->p_nodes[i]);
194	}
195	}
196
197	memset(p_dict, 0, sizeof(*p_dict));
198
199	p_dict->p_nodes[0] = p_trie_node_pool->p_node_free_list;
200	p_trie_node_pool->p_node_free_list = p_dict;
201
202	p_trie_node_pool->node_count--;
203	}
204
205	int trie_dict_set(TRIE_NODE p_dict, const char key, int64_t value)
206	{
207	int offset;
208
209	if (p_dict == NULL)
210	{
211	return -1;
212	}
213
214	while (key != NULL && *key != '\0')
215	{
216	offset = (unsigned char)(*key);
217	if (offset < 0 \|\| offset >= TRIE_CHILDREN) // incorrect key character
218	{
219	return -1;
220	}
221
222	if (*(key + 1) == '\0')
223	{
224	if (p_dict->flags[offset] == 0 \|\| p_dict->values[offset] != value)
225	{
226	p_dict->values[offset] = value;
227	p_dict->flags[offset] = 1;
228	return 1; // Set to new value
229	}
230	return 0; // Unchanged
231	}
232	else
233	{
234	if (p_dict->p_nodes[offset] == NULL)
235	{
236	if ((p_dict->p_nodes[offset] = trie_dict_create()) == NULL)
237	{
238	return -2; // OOM
239	}
240	}
241	p_dict = p_dict->p_nodes[offset];
242	key++;
243	}
244	}
245
246	return -1; // NULL key
247	}
248
249	int trie_dict_get(TRIE_NODE p_dict, const char key, int64_t *p_value)
250	{
251	int offset;
252
253	if (p_dict == NULL)
254	{
255	return -1;
256	}
257
258	while (key != NULL && *key != '\0')
259	{
260	offset = (unsigned char)(*key);
261	if (offset < 0 \|\| offset >= TRIE_CHILDREN) // incorrect key character
262	{
263	return -1;
264	}
265
266	if (*(key + 1) == '\0')
267	{
268	if (p_dict->flags[offset] != 0)
269	{
270	*p_value = p_dict->values[offset];
271	return 1; // Found
272	}
273	else
274	{
275	return 0; // Not exist
276	}
277	}
278	else if (p_dict->p_nodes[offset] == NULL)
279	{
280	return 0; // Not exist
281	}
282	else
283	{
284	p_dict = p_dict->p_nodes[offset];
285	key++;
286	}
287	}
288
289	return -1; // NULL key
290	}
291
292	int trie_dict_del(TRIE_NODE p_dict, const char key)
293	{
294	int offset;
295
296	if (p_dict == NULL)
297	{
298	return -1;
299	}
300
301	while (key != NULL && *key != '\0')
302	{
303	offset = (unsigned char)(*key);
304	if (offset < 0 \|\| offset >= TRIE_CHILDREN) // incorrect key character
305	{
306	return -1;
307	}
308
309	if (*(key + 1) == '\0')
310	{
311	if (p_dict->flags[offset] != 0)
312	{
313	p_dict->flags[offset] = 0;
314	p_dict->values[offset] = 0;
315	return 1; // Done
316	}
317	else
318	{
319	return 0; // Not exist
320	}
321	}
322	else if (p_dict->p_nodes[offset] == NULL)
323	{
324	return 0; // Not exist
325	}
326	else
327	{
328	p_dict = p_dict->p_nodes[offset];
329	key++;
330	}
331	}
332
333	return -1; // NULL key
334	}
335
336	static void _trie_dict_traverse(TRIE_NODE p_dict, trie_dict_traverse_cb cb, char key, int depth)
337	{
338	if (p_dict == NULL \|\| depth >= TRIE_MAX_KEY_LEN)
339	{
340	return;
341	}
342
343	for (int i = 0; i < TRIE_CHILDREN; i++)
344	{
345	if (p_dict->flags[i] != 0)
346	{
347	key[depth] = (char)i;
348	key[depth + 1] = '\0';
349	(*cb)(key, p_dict->values[i]);
350	}
351
352	if (p_dict->p_nodes[i] != NULL && depth + 1 < TRIE_MAX_KEY_LEN)
353	{
354	key[depth] = (char)i;
355	_trie_dict_traverse(p_dict->p_nodes[i], cb, key, depth + 1);
356	}
357	}
358	}
359
360	void trie_dict_traverse(TRIE_NODE *p_dict, trie_dict_traverse_cb cb)
361	{
362	char key[TRIE_MAX_KEY_LEN + 1];
363
364	if (p_dict == NULL)
365	{
366	return;
367	}
368
369	_trie_dict_traverse(p_dict, cb, key, 0);
370	}
371
372	int trie_dict_used_nodes(void)
373	{
374	return (p_trie_node_pool == NULL ? -1 : p_trie_node_pool->node_count);
375	}
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