lbbs/src/trie_dict.c

/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
 * trie_dict
 *   - trie-tree based dict feature
 *
 * Copyright (C) 2004-2025  Leaflet <leaflet@leafok.com>
 */

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

#include "log.h"
#include "trie_dict.h"
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/ipc.h>
#include <sys/shm.h>

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

static TRIE_NODE_POOL *p_trie_node_pool;

int trie_dict_init(const char *filename, int node_count_limit)
{
        int shmid;
        int proj_id;
        key_t key;
        size_t size;
        void *p_shm;
        TRIE_NODE *p_trie_nodes;
        int i;

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

        // Allocate shared memory
        proj_id = (int)(time(NULL) % getpid());
        key = ftok(filename, proj_id);
        if (key == -1)
        {
                log_error("ftok(%s, %d) error (%d)\n", filename, proj_id, errno);
                return -2;
        }

        size = sizeof(TRIE_NODE_POOL) + sizeof(TRIE_NODE) * (size_t)node_count_limit;
        shmid = shmget(key, size, IPC_CREAT | IPC_EXCL | 0600);
        if (shmid == -1)
        {
                log_error("shmget(size = %d) error (%d)\n", size, errno);
                return -3;
        }
        p_shm = shmat(shmid, NULL, 0);
        if (p_shm == (void *)-1)
        {
                log_error("shmat(shmid = %d) error (%d)\n", shmid, errno);
                return -3;
        }

        p_trie_node_pool = p_shm;
        p_trie_node_pool->shmid = shmid;
        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)
{
        int shmid;

        if (p_trie_node_pool == NULL)
        {
                return;
        }

        shmid = p_trie_node_pool->shmid;

        detach_trie_dict_shm();

        if (shmid != 0 && shmctl(shmid, IPC_RMID, NULL) == -1)
        {
                log_error("shmctl(shmid = %d, IPC_RMID) error (%d)\n", shmid, errno);
        }
}

int set_trie_dict_shm_readonly(void)
{
        int shmid;
        void *p_shm;

        if (p_trie_node_pool == NULL)
        {
                log_error("trie_dict_pool not initialized\n");
                return -1;
        }

        shmid = p_trie_node_pool->shmid;

        // Remap shared memory in read-only mode
        p_shm = shmat(shmid, p_trie_node_pool, SHM_RDONLY | SHM_REMAP);
        if (p_shm == (void *)-1)
        {
                log_error("shmat(trie_node_pool shmid=%d) error (%d)\n", shmid, errno);
                return -1;
        }

        p_trie_node_pool = p_shm;

        return 0;
}

int detach_trie_dict_shm(void)
{
        if (p_trie_node_pool != NULL && shmdt(p_trie_node_pool) == -1)
        {
                log_error("shmdt(trie_node_pool) error (%d)\n", 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\n", 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 = (256 + *key) % 256;
                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 = (256 + *key) % 256;
                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 = (256 + *key) % 256;
                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	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	1.11	#include "log.h"
14	sysadm	1.1	#include "trie_dict.h"
15	sysadm	1.7	#include <errno.h>
16	sysadm	1.10	#include <stdio.h>
17	sysadm	1.1	#include <stdlib.h>
18	sysadm	1.10	#include <string.h>
19	sysadm	1.7	#include <time.h>
20			#include <unistd.h>
21	sysadm	1.11	#include <sys/ipc.h>
22	sysadm	1.7	#include <sys/shm.h>
23
24			struct trie_node_pool_t
25			{
26			int shmid;
27	sysadm	1.8	int node_count_limit;
28			int node_count;
29	sysadm	1.7	TRIE_NODE *p_node_free_list;
30			};
31			typedef struct trie_node_pool_t TRIE_NODE_POOL;
32
33			static TRIE_NODE_POOL *p_trie_node_pool;
34
35	sysadm	1.8	int trie_dict_init(const char *filename, int node_count_limit)
36	sysadm	1.7	{
37			int shmid;
38			int proj_id;
39			key_t key;
40			size_t size;
41			void *p_shm;
42	sysadm	1.8	TRIE_NODE *p_trie_nodes;
43	sysadm	1.7	int i;
44
45			if (p_trie_node_pool != NULL)
46			{
47			log_error("trie_dict_pool already initialized\n");
48			return -1;
49			}
50
51	sysadm	1.8	if (node_count_limit <= 0 \|\| node_count_limit > TRIE_NODE_PER_POOL)
52			{
53			log_error("trie_dict_init(%d) error: invalid node_count_limit\n", node_count_limit);
54			return -1;
55			}
56
57	sysadm	1.7	// Allocate shared memory
58			proj_id = (int)(time(NULL) % getpid());
59			key = ftok(filename, proj_id);
60			if (key == -1)
61			{
62			log_error("ftok(%s, %d) error (%d)\n", filename, proj_id, errno);
63			return -2;
64			}
65
66	sysadm	1.8	size = sizeof(TRIE_NODE_POOL) + sizeof(TRIE_NODE) * (size_t)node_count_limit;
67	sysadm	1.7	shmid = shmget(key, size, IPC_CREAT \| IPC_EXCL \| 0600);
68			if (shmid == -1)
69			{
70			log_error("shmget(size = %d) error (%d)\n", size, errno);
71			return -3;
72			}
73			p_shm = shmat(shmid, NULL, 0);
74			if (p_shm == (void *)-1)
75			{
76			log_error("shmat(shmid = %d) error (%d)\n", shmid, errno);
77			return -3;
78			}
79
80			p_trie_node_pool = p_shm;
81			p_trie_node_pool->shmid = shmid;
82	sysadm	1.8	p_trie_node_pool->node_count_limit = node_count_limit;
83	sysadm	1.7	p_trie_node_pool->node_count = 0;
84
85	sysadm	1.12	p_trie_nodes = (TRIE_NODE )((char )p_shm + sizeof(TRIE_NODE_POOL));
86	sysadm	1.8	p_trie_node_pool->p_node_free_list = &(p_trie_nodes[0]);
87			for (i = 0; i < node_count_limit - 1; i++)
88	sysadm	1.7	{
89	sysadm	1.8	p_trie_nodes[i].p_nodes[0] = &(p_trie_nodes[i + 1]);
90	sysadm	1.7	}
91	sysadm	1.8	p_trie_nodes[node_count_limit - 1].p_nodes[0] = NULL;
92	sysadm	1.7
93			return 0;
94			}
95
96			void trie_dict_cleanup(void)
97			{
98			int shmid;
99
100			if (p_trie_node_pool == NULL)
101			{
102			return;
103			}
104
105			shmid = p_trie_node_pool->shmid;
106
107			detach_trie_dict_shm();
108
109	sysadm	1.14	if (shmid != 0 && shmctl(shmid, IPC_RMID, NULL) == -1)
110	sysadm	1.7	{
111			log_error("shmctl(shmid = %d, IPC_RMID) error (%d)\n", shmid, errno);
112			}
113			}
114
115			int set_trie_dict_shm_readonly(void)
116			{
117			int shmid;
118			void *p_shm;
119
120			if (p_trie_node_pool == NULL)
121			{
122			log_error("trie_dict_pool not initialized\n");
123			return -1;
124			}
125
126			shmid = p_trie_node_pool->shmid;
127
128			// Remap shared memory in read-only mode
129			p_shm = shmat(shmid, p_trie_node_pool, SHM_RDONLY \| SHM_REMAP);
130			if (p_shm == (void *)-1)
131			{
132	sysadm	1.9	log_error("shmat(trie_node_pool shmid=%d) error (%d)\n", shmid, errno);
133	sysadm	1.7	return -1;
134			}
135
136			p_trie_node_pool = p_shm;
137
138			return 0;
139			}
140
141			int detach_trie_dict_shm(void)
142			{
143			if (p_trie_node_pool != NULL && shmdt(p_trie_node_pool) == -1)
144			{
145	sysadm	1.9	log_error("shmdt(trie_node_pool) error (%d)\n", errno);
146	sysadm	1.7	return -1;
147			}
148	sysadm	1.8
149	sysadm	1.7	p_trie_node_pool = NULL;
150
151			return 0;
152			}
153	sysadm	1.1
154			TRIE_NODE *trie_dict_create(void)
155			{
156	sysadm	1.7	TRIE_NODE *p_dict = NULL;
157
158			if (p_trie_node_pool != NULL && p_trie_node_pool->p_node_free_list != NULL)
159			{
160			p_dict = p_trie_node_pool->p_node_free_list;
161			p_trie_node_pool->p_node_free_list = p_dict->p_nodes[0];
162	sysadm	1.1
163	sysadm	1.10	memset(p_dict, 0, sizeof(*p_dict));
164	sysadm	1.8
165			p_trie_node_pool->node_count++;
166			}
167			else if (p_trie_node_pool != NULL)
168			{
169			log_error("trie_dict_create() error: node depleted %d >= %d\n", p_trie_node_pool->node_count, p_trie_node_pool->node_count_limit);
170	sysadm	1.7	}
171	sysadm	1.1
172			return p_dict;
173			}
174
175			void trie_dict_destroy(TRIE_NODE *p_dict)
176			{
177	sysadm	1.7	if (p_trie_node_pool == NULL \|\| p_dict == NULL)
178	sysadm	1.1	{
179			return;
180			}
181
182			for (int i = 0; i < TRIE_CHILDREN; i++)
183			{
184			if (p_dict->p_nodes[i] != NULL)
185			{
186			trie_dict_destroy(p_dict->p_nodes[i]);
187			}
188	sysadm	1.7	}
189	sysadm	1.3
190	sysadm	1.10	memset(p_dict, 0, sizeof(*p_dict));
191	sysadm	1.1
192	sysadm	1.7	p_dict->p_nodes[0] = p_trie_node_pool->p_node_free_list;
193			p_trie_node_pool->p_node_free_list = p_dict;
194	sysadm	1.8
195			p_trie_node_pool->node_count--;
196	sysadm	1.1	}
197
198			int trie_dict_set(TRIE_NODE p_dict, const char key, int64_t value)
199			{
200			int offset;
201
202	sysadm	1.5	if (p_dict == NULL)
203			{
204			return -1;
205			}
206
207	sysadm	1.1	while (key != NULL && *key != '\0')
208			{
209	sysadm	1.6	offset = (256 + *key) % 256;
210	sysadm	1.3	if (offset < 0 \|\| offset >= TRIE_CHILDREN) // incorrect key character
211			{
212			return -1;
213			}
214	sysadm	1.1
215			if (*(key + 1) == '\0')
216			{
217			if (p_dict->flags[offset] == 0 \|\| p_dict->values[offset] != value)
218			{
219			p_dict->values[offset] = value;
220			p_dict->flags[offset] = 1;
221			return 1; // Set to new value
222			}
223			return 0; // Unchanged
224			}
225			else
226			{
227			if (p_dict->p_nodes[offset] == NULL)
228			{
229			if ((p_dict->p_nodes[offset] = trie_dict_create()) == NULL)
230			{
231			return -2; // OOM
232			}
233			}
234			p_dict = p_dict->p_nodes[offset];
235			key++;
236			}
237			}
238
239			return -1; // NULL key
240			}
241
242			int trie_dict_get(TRIE_NODE p_dict, const char key, int64_t *p_value)
243			{
244			int offset;
245
246	sysadm	1.5	if (p_dict == NULL)
247			{
248			return -1;
249			}
250
251	sysadm	1.1	while (key != NULL && *key != '\0')
252			{
253	sysadm	1.6	offset = (256 + *key) % 256;
254	sysadm	1.3	if (offset < 0 \|\| offset >= TRIE_CHILDREN) // incorrect key character
255			{
256			return -1;
257			}
258	sysadm	1.1
259			if (*(key + 1) == '\0')
260			{
261			if (p_dict->flags[offset] != 0)
262			{
263			*p_value = p_dict->values[offset];
264			return 1; // Found
265			}
266			else
267			{
268			return 0; // Not exist
269			}
270			}
271			else if (p_dict->p_nodes[offset] == NULL)
272			{
273			return 0; // Not exist
274			}
275			else
276			{
277			p_dict = p_dict->p_nodes[offset];
278			key++;
279			}
280			}
281
282			return -1; // NULL key
283			}
284
285			int trie_dict_del(TRIE_NODE p_dict, const char key)
286			{
287			int offset;
288
289	sysadm	1.5	if (p_dict == NULL)
290			{
291			return -1;
292			}
293
294	sysadm	1.1	while (key != NULL && *key != '\0')
295			{
296	sysadm	1.6	offset = (256 + *key) % 256;
297	sysadm	1.3	if (offset < 0 \|\| offset >= TRIE_CHILDREN) // incorrect key character
298			{
299			return -1;
300			}
301	sysadm	1.1
302			if (*(key + 1) == '\0')
303			{
304			if (p_dict->flags[offset] != 0)
305			{
306			p_dict->flags[offset] = 0;
307			p_dict->values[offset] = 0;
308			return 1; // Done
309			}
310			else
311			{
312			return 0; // Not exist
313			}
314			}
315			else if (p_dict->p_nodes[offset] == NULL)
316			{
317			return 0; // Not exist
318			}
319			else
320			{
321			p_dict = p_dict->p_nodes[offset];
322			key++;
323			}
324			}
325
326			return -1; // NULL key
327			}
328	sysadm	1.2
329			static void _trie_dict_traverse(TRIE_NODE p_dict, trie_dict_traverse_cb cb, char key, int depth)
330			{
331			if (p_dict == NULL \|\| depth >= TRIE_MAX_KEY_LEN)
332			{
333			return;
334			}
335
336			for (int i = 0; i < TRIE_CHILDREN; i++)
337			{
338			if (p_dict->flags[i] != 0)
339			{
340	sysadm	1.5	key[depth] = (char)i;
341	sysadm	1.3	key[depth + 1] = '\0';
342	sysadm	1.2	(*cb)(key, p_dict->values[i]);
343			}
344
345			if (p_dict->p_nodes[i] != NULL && depth + 1 < TRIE_MAX_KEY_LEN)
346			{
347	sysadm	1.5	key[depth] = (char)i;
348	sysadm	1.2	_trie_dict_traverse(p_dict->p_nodes[i], cb, key, depth + 1);
349			}
350	sysadm	1.5	}
351	sysadm	1.2	}
352
353			void trie_dict_traverse(TRIE_NODE *p_dict, trie_dict_traverse_cb cb)
354			{
355			char key[TRIE_MAX_KEY_LEN + 1];
356	sysadm	1.5
357			if (p_dict == NULL)
358			{
359			return;
360			}
361	sysadm	1.2
362			_trie_dict_traverse(p_dict, cb, key, 0);
363			}
364	sysadm	1.8
365			int trie_dict_used_nodes(void)
366			{
367			return (p_trie_node_pool == NULL ? -1 : p_trie_node_pool->node_count);
368			}
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