lbbs/src/trie_dict.c

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

#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			* Copyright (C) 2004-2025 by Leaflet <leaflet@leafok.com>
7			*/
8	sysadm	1.1
9	sysadm	1.11	#include "log.h"
10	sysadm	1.1	#include "trie_dict.h"
11	sysadm	1.7	#include <errno.h>
12	sysadm	1.10	#include <stdio.h>
13	sysadm	1.1	#include <stdlib.h>
14	sysadm	1.10	#include <string.h>
15	sysadm	1.7	#include <time.h>
16			#include <unistd.h>
17	sysadm	1.11	#include <sys/ipc.h>
18	sysadm	1.7	#include <sys/shm.h>
19
20			struct trie_node_pool_t
21			{
22			int shmid;
23	sysadm	1.8	int node_count_limit;
24			int node_count;
25	sysadm	1.7	TRIE_NODE *p_node_free_list;
26			};
27			typedef struct trie_node_pool_t TRIE_NODE_POOL;
28
29			static TRIE_NODE_POOL *p_trie_node_pool;
30
31	sysadm	1.8	int trie_dict_init(const char *filename, int node_count_limit)
32	sysadm	1.7	{
33			int shmid;
34			int proj_id;
35			key_t key;
36			size_t size;
37			void *p_shm;
38	sysadm	1.8	TRIE_NODE *p_trie_nodes;
39	sysadm	1.7	int i;
40
41			if (p_trie_node_pool != NULL)
42			{
43			log_error("trie_dict_pool already initialized\n");
44			return -1;
45			}
46
47	sysadm	1.8	if (node_count_limit <= 0 \|\| node_count_limit > TRIE_NODE_PER_POOL)
48			{
49			log_error("trie_dict_init(%d) error: invalid node_count_limit\n", node_count_limit);
50			return -1;
51			}
52
53	sysadm	1.7	// Allocate shared memory
54			proj_id = (int)(time(NULL) % getpid());
55			key = ftok(filename, proj_id);
56			if (key == -1)
57			{
58			log_error("ftok(%s, %d) error (%d)\n", filename, proj_id, errno);
59			return -2;
60			}
61
62	sysadm	1.8	size = sizeof(TRIE_NODE_POOL) + sizeof(TRIE_NODE) * (size_t)node_count_limit;
63	sysadm	1.7	shmid = shmget(key, size, IPC_CREAT \| IPC_EXCL \| 0600);
64			if (shmid == -1)
65			{
66			log_error("shmget(size = %d) error (%d)\n", size, errno);
67			return -3;
68			}
69			p_shm = shmat(shmid, NULL, 0);
70			if (p_shm == (void *)-1)
71			{
72			log_error("shmat(shmid = %d) error (%d)\n", shmid, errno);
73			return -3;
74			}
75
76			p_trie_node_pool = p_shm;
77			p_trie_node_pool->shmid = shmid;
78	sysadm	1.8	p_trie_node_pool->node_count_limit = node_count_limit;
79	sysadm	1.7	p_trie_node_pool->node_count = 0;
80
81	sysadm	1.12	p_trie_nodes = (TRIE_NODE )((char )p_shm + sizeof(TRIE_NODE_POOL));
82	sysadm	1.8	p_trie_node_pool->p_node_free_list = &(p_trie_nodes[0]);
83			for (i = 0; i < node_count_limit - 1; i++)
84	sysadm	1.7	{
85	sysadm	1.8	p_trie_nodes[i].p_nodes[0] = &(p_trie_nodes[i + 1]);
86	sysadm	1.7	}
87	sysadm	1.8	p_trie_nodes[node_count_limit - 1].p_nodes[0] = NULL;
88	sysadm	1.7
89			return 0;
90			}
91
92			void trie_dict_cleanup(void)
93			{
94			int shmid;
95
96			if (p_trie_node_pool == NULL)
97			{
98			return;
99			}
100
101			shmid = p_trie_node_pool->shmid;
102
103			detach_trie_dict_shm();
104
105	sysadm	1.14	if (shmid != 0 && shmctl(shmid, IPC_RMID, NULL) == -1)
106	sysadm	1.7	{
107			log_error("shmctl(shmid = %d, IPC_RMID) error (%d)\n", shmid, errno);
108			}
109			}
110
111			int set_trie_dict_shm_readonly(void)
112			{
113			int shmid;
114			void *p_shm;
115
116			if (p_trie_node_pool == NULL)
117			{
118			log_error("trie_dict_pool not initialized\n");
119			return -1;
120			}
121
122			shmid = p_trie_node_pool->shmid;
123
124			// Remap shared memory in read-only mode
125			p_shm = shmat(shmid, p_trie_node_pool, SHM_RDONLY \| SHM_REMAP);
126			if (p_shm == (void *)-1)
127			{
128	sysadm	1.9	log_error("shmat(trie_node_pool shmid=%d) error (%d)\n", shmid, errno);
129	sysadm	1.7	return -1;
130			}
131
132			p_trie_node_pool = p_shm;
133
134			return 0;
135			}
136
137			int detach_trie_dict_shm(void)
138			{
139			if (p_trie_node_pool != NULL && shmdt(p_trie_node_pool) == -1)
140			{
141	sysadm	1.9	log_error("shmdt(trie_node_pool) error (%d)\n", errno);
142	sysadm	1.7	return -1;
143			}
144	sysadm	1.8
145	sysadm	1.7	p_trie_node_pool = NULL;
146
147			return 0;
148			}
149	sysadm	1.1
150			TRIE_NODE *trie_dict_create(void)
151			{
152	sysadm	1.7	TRIE_NODE *p_dict = NULL;
153
154			if (p_trie_node_pool != NULL && p_trie_node_pool->p_node_free_list != NULL)
155			{
156			p_dict = p_trie_node_pool->p_node_free_list;
157			p_trie_node_pool->p_node_free_list = p_dict->p_nodes[0];
158	sysadm	1.1
159	sysadm	1.10	memset(p_dict, 0, sizeof(*p_dict));
160	sysadm	1.8
161			p_trie_node_pool->node_count++;
162			}
163			else if (p_trie_node_pool != NULL)
164			{
165			log_error("trie_dict_create() error: node depleted %d >= %d\n", p_trie_node_pool->node_count, p_trie_node_pool->node_count_limit);
166	sysadm	1.7	}
167	sysadm	1.1
168			return p_dict;
169			}
170
171			void trie_dict_destroy(TRIE_NODE *p_dict)
172			{
173	sysadm	1.7	if (p_trie_node_pool == NULL \|\| p_dict == NULL)
174	sysadm	1.1	{
175			return;
176			}
177
178			for (int i = 0; i < TRIE_CHILDREN; i++)
179			{
180			if (p_dict->p_nodes[i] != NULL)
181			{
182			trie_dict_destroy(p_dict->p_nodes[i]);
183			}
184	sysadm	1.7	}
185	sysadm	1.3
186	sysadm	1.10	memset(p_dict, 0, sizeof(*p_dict));
187	sysadm	1.1
188	sysadm	1.7	p_dict->p_nodes[0] = p_trie_node_pool->p_node_free_list;
189			p_trie_node_pool->p_node_free_list = p_dict;
190	sysadm	1.8
191			p_trie_node_pool->node_count--;
192	sysadm	1.1	}
193
194			int trie_dict_set(TRIE_NODE p_dict, const char key, int64_t value)
195			{
196			int offset;
197
198	sysadm	1.5	if (p_dict == NULL)
199			{
200			return -1;
201			}
202
203	sysadm	1.1	while (key != NULL && *key != '\0')
204			{
205	sysadm	1.6	offset = (256 + *key) % 256;
206	sysadm	1.3	if (offset < 0 \|\| offset >= TRIE_CHILDREN) // incorrect key character
207			{
208			return -1;
209			}
210	sysadm	1.1
211			if (*(key + 1) == '\0')
212			{
213			if (p_dict->flags[offset] == 0 \|\| p_dict->values[offset] != value)
214			{
215			p_dict->values[offset] = value;
216			p_dict->flags[offset] = 1;
217			return 1; // Set to new value
218			}
219			return 0; // Unchanged
220			}
221			else
222			{
223			if (p_dict->p_nodes[offset] == NULL)
224			{
225			if ((p_dict->p_nodes[offset] = trie_dict_create()) == NULL)
226			{
227			return -2; // OOM
228			}
229			}
230			p_dict = p_dict->p_nodes[offset];
231			key++;
232			}
233			}
234
235			return -1; // NULL key
236			}
237
238			int trie_dict_get(TRIE_NODE p_dict, const char key, int64_t *p_value)
239			{
240			int offset;
241
242	sysadm	1.5	if (p_dict == NULL)
243			{
244			return -1;
245			}
246
247	sysadm	1.1	while (key != NULL && *key != '\0')
248			{
249	sysadm	1.6	offset = (256 + *key) % 256;
250	sysadm	1.3	if (offset < 0 \|\| offset >= TRIE_CHILDREN) // incorrect key character
251			{
252			return -1;
253			}
254	sysadm	1.1
255			if (*(key + 1) == '\0')
256			{
257			if (p_dict->flags[offset] != 0)
258			{
259			*p_value = p_dict->values[offset];
260			return 1; // Found
261			}
262			else
263			{
264			return 0; // Not exist
265			}
266			}
267			else if (p_dict->p_nodes[offset] == NULL)
268			{
269			return 0; // Not exist
270			}
271			else
272			{
273			p_dict = p_dict->p_nodes[offset];
274			key++;
275			}
276			}
277
278			return -1; // NULL key
279			}
280
281			int trie_dict_del(TRIE_NODE p_dict, const char key)
282			{
283			int offset;
284
285	sysadm	1.5	if (p_dict == NULL)
286			{
287			return -1;
288			}
289
290	sysadm	1.1	while (key != NULL && *key != '\0')
291			{
292	sysadm	1.6	offset = (256 + *key) % 256;
293	sysadm	1.3	if (offset < 0 \|\| offset >= TRIE_CHILDREN) // incorrect key character
294			{
295			return -1;
296			}
297	sysadm	1.1
298			if (*(key + 1) == '\0')
299			{
300			if (p_dict->flags[offset] != 0)
301			{
302			p_dict->flags[offset] = 0;
303			p_dict->values[offset] = 0;
304			return 1; // Done
305			}
306			else
307			{
308			return 0; // Not exist
309			}
310			}
311			else if (p_dict->p_nodes[offset] == NULL)
312			{
313			return 0; // Not exist
314			}
315			else
316			{
317			p_dict = p_dict->p_nodes[offset];
318			key++;
319			}
320			}
321
322			return -1; // NULL key
323			}
324	sysadm	1.2
325			static void _trie_dict_traverse(TRIE_NODE p_dict, trie_dict_traverse_cb cb, char key, int depth)
326			{
327			if (p_dict == NULL \|\| depth >= TRIE_MAX_KEY_LEN)
328			{
329			return;
330			}
331
332			for (int i = 0; i < TRIE_CHILDREN; i++)
333			{
334			if (p_dict->flags[i] != 0)
335			{
336	sysadm	1.5	key[depth] = (char)i;
337	sysadm	1.3	key[depth + 1] = '\0';
338	sysadm	1.2	(*cb)(key, p_dict->values[i]);
339			}
340
341			if (p_dict->p_nodes[i] != NULL && depth + 1 < TRIE_MAX_KEY_LEN)
342			{
343	sysadm	1.5	key[depth] = (char)i;
344	sysadm	1.2	_trie_dict_traverse(p_dict->p_nodes[i], cb, key, depth + 1);
345			}
346	sysadm	1.5	}
347	sysadm	1.2	}
348
349			void trie_dict_traverse(TRIE_NODE *p_dict, trie_dict_traverse_cb cb)
350			{
351			char key[TRIE_MAX_KEY_LEN + 1];
352	sysadm	1.5
353			if (p_dict == NULL)
354			{
355			return;
356			}
357	sysadm	1.2
358			_trie_dict_traverse(p_dict, cb, key, 0);
359			}
360	sysadm	1.8
361			int trie_dict_used_nodes(void)
362			{
363			return (p_trie_node_pool == NULL ? -1 : p_trie_node_pool->node_count);
364			}
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