lbbs/src/section_list.c

/***************************************************************************
                                           section_list.c  -  description
                                                         -------------------
        Copyright            : (C) 2004-2025 by Leaflet
        Email                : leaflet@leafok.com
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 3 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

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

#define ARTICLE_BLOCK_PER_SHM 50 // sizeof(ARTICLE_BLOCK) * ARTICLE_BLOCK_PER_SHM is the size of each shm segment to allocate
#define ARTICLE_BLOCK_SHM_COUNT_LIMIT 256

struct article_block_shm_t
{
        int shmid;
        void *p_shm;
};
typedef struct article_block_shm_t ARTICLE_BLOCK_SHM;

static ARTICLE_BLOCK_SHM *p_article_block_shm_pool;
static int article_block_shm_count;
static ARTICLE_BLOCK *p_article_block_free_list;

static SECTION_DATA *p_section_data_pool;
static int section_data_count;
static TRIE_NODE *p_trie_dict_section_data;

int section_data_pool_init(const char *filename, int article_block_count)
{
        int shmid;
        int proj_id;
        key_t key;
        size_t size;
        void *p_shm;
        int i;
        int article_block_count_in_shm;
        ARTICLE_BLOCK *p_article_block_in_shm;
        ARTICLE_BLOCK **pp_article_block_next;

        if (p_article_block_shm_pool != NULL ||
                p_article_block_free_list != NULL ||
                p_section_data_pool != NULL ||
                p_trie_dict_section_data != NULL)
        {
                log_error("section_data_pool already initialized\n");
                return -1;
        }

        if (article_block_count > ARTICLE_BLOCK_PER_SHM * ARTICLE_BLOCK_SHM_COUNT_LIMIT)
        {
                log_error("article_block_count exceed limit %d\n", ARTICLE_BLOCK_PER_SHM * ARTICLE_BLOCK_SHM_COUNT_LIMIT);
                return -2;
        }

        p_article_block_shm_pool = calloc((size_t)article_block_count / ARTICLE_BLOCK_PER_SHM + 1, sizeof(ARTICLE_BLOCK_SHM));
        if (p_article_block_shm_pool == NULL)
        {
                log_error("calloc(%d ARTICLE_BLOCK_SHM) OOM\n", article_block_count / ARTICLE_BLOCK_PER_SHM + 1);
                return -2;
        }

        p_section_data_pool = calloc(BBS_max_section, sizeof(SECTION_DATA));
        if (p_section_data_pool == NULL)
        {
                log_error("calloc(%d SECTION_DATA) OOM\n", BBS_max_section);
                return -2;
        }
        section_data_count = 0;

        p_trie_dict_section_data = trie_dict_create();
        if (p_trie_dict_section_data == NULL)
        {
                log_error("trie_dict_create() OOM\n", BBS_max_section);
                return -2;
        }

        // Allocate shared memory
        article_block_shm_count = 0;
        pp_article_block_next = &p_article_block_free_list;

        while (article_block_count > 0)
        {
                article_block_count_in_shm =
                        (article_block_count < ARTICLE_BLOCK_PER_SHM ? article_block_count : ARTICLE_BLOCK_PER_SHM);
                article_block_count -= article_block_count_in_shm;

                proj_id = getpid() + article_block_shm_count;
                key = ftok(filename, proj_id);
                if (key == -1)
                {
                        log_error("ftok(%s, %d) error (%d)\n", filename, proj_id, errno);
                        section_data_pool_cleanup();
                        return -3;
                }

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

                (p_article_block_shm_pool + article_block_shm_count)->shmid = shmid;
                (p_article_block_shm_pool + article_block_shm_count)->p_shm = p_shm;
                article_block_shm_count++;

                p_article_block_in_shm = p_shm;
                *pp_article_block_next = p_article_block_in_shm;

                for (i = 0; i < article_block_count_in_shm; i++)
                {
                        if (i < article_block_count_in_shm - 1)
                        {
                                (p_article_block_in_shm + i)->p_next_block = (p_article_block_in_shm + i + 1);
                        }
                        else
                        {
                                (p_article_block_in_shm + i)->p_next_block = NULL;
                                pp_article_block_next = &((p_article_block_in_shm + i)->p_next_block);
                        }
                }
        }

        return 0;
}

void section_data_pool_cleanup(void)
{
        int i;

        if (p_trie_dict_section_data != NULL)
        {
                trie_dict_destroy(p_trie_dict_section_data);
                p_trie_dict_section_data = NULL;
                section_data_count = 0;
        }

        if (p_section_data_pool != NULL)
        {
                free(p_section_data_pool);
                p_section_data_pool = NULL;
        }

        if (p_article_block_free_list != NULL)
        {
                p_article_block_free_list = NULL;
        }

        if (p_article_block_shm_pool != NULL)
        {
                for (i = 0; i < article_block_shm_count; i++)
                {
                        if (shmdt((p_article_block_shm_pool + i)->p_shm) == -1)
                        {
                                log_error("shmdt(shmid = %d) error (%d)\n", (p_article_block_shm_pool + i)->shmid, errno);
                        }

                        if (shmctl((p_article_block_shm_pool + i)->shmid, IPC_RMID, NULL) == -1)
                        {
                                log_error("shmctl(shmid = %d, IPC_RMID) error (%d)\n", (p_article_block_shm_pool + i)->shmid, errno);
                        }
                }

                p_article_block_shm_pool = NULL;
                article_block_shm_count = 0;
        }
}

inline static ARTICLE_BLOCK *pop_free_article_block(void)
{
        ARTICLE_BLOCK *p_article_block = NULL;

        if (p_article_block_free_list != NULL)
        {
                p_article_block = p_article_block_free_list;
                p_article_block_free_list = p_article_block_free_list->p_next_block;
        }

        return p_article_block;
}

inline static void push_free_article_block(ARTICLE_BLOCK *p_article_block)
{
        p_article_block->p_next_block = p_article_block_free_list;
        p_article_block_free_list = p_article_block;
}

SECTION_DATA *section_data_create(const char *sname, const char *stitle, const char *master_name)
{
        SECTION_DATA *p_section;
        int index;

        if (p_section_data_pool == NULL || p_trie_dict_section_data == NULL)
        {
                log_error("section_data not initialized\n");
                return NULL;
        }

        if (section_data_count >= BBS_max_section)
        {
                log_error("section_data_count exceed limit %d\n", BBS_max_section);
                return NULL;
        }

        index = section_data_count;
        p_section = p_section_data_pool + index;

        strncpy(p_section->sname, sname, sizeof(p_section->sname - 1));
        p_section->sname[sizeof(p_section->sname - 1)] = '\0';

        strncpy(p_section->stitle, stitle, sizeof(p_section->stitle - 1));
        p_section->stitle[sizeof(p_section->stitle - 1)] = '\0';

        strncpy(p_section->master_name, master_name, sizeof(p_section->master_name - 1));
        p_section->master_name[sizeof(p_section->master_name - 1)] = '\0';

        p_section->p_head_block = NULL;
        p_section->p_tail_block = NULL;
        p_section->block_count = 0;
        p_section->article_count = 0;
        p_section->delete_count = 0;

        if (trie_dict_set(p_trie_dict_section_data, sname, index) != 1)
        {
                log_error("trie_dict_set(section_data, %s, %d) error\n", sname, index);
                return NULL;
        }

        section_data_count++;

        return p_section;
}

int section_data_free_block(SECTION_DATA *p_section)
{
        ARTICLE_BLOCK *p_block;

        if (p_section == NULL)
        {
                log_error("section_data_free_block() NULL pointer error\n");
                return -1;
        }

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

        while (p_section->p_head_block != NULL)
        {
                p_block = p_section->p_head_block;
                p_section->p_head_block = p_block->p_next_block;
                push_free_article_block(p_block);
        }

        p_section->p_tail_block = NULL;
        p_section->block_count = 0;
        p_section->article_count = 0;
        p_section->delete_count = 0;

        return 0;
}

SECTION_DATA *section_data_find_by_name(const char *sname)
{
        int64_t index;

        if (p_section_data_pool == NULL || p_trie_dict_section_data == NULL)
        {
                log_error("section_data not initialized\n");
                return NULL;
        }

        if (trie_dict_get(p_trie_dict_section_data, sname, &index) != 1)
        {
                log_error("trie_dict_get(section_data, %s) error\n", sname);
                return NULL;
        }

        return (p_section_data_pool + index);
}

int section_data_append_article(SECTION_DATA *p_section, const ARTICLE *p_article)
{
        ARTICLE_BLOCK *p_block;
        int32_t last_aid = 0;
        ARTICLE *p_topic_head;
        ARTICLE *p_topic_tail;

        if (p_section == NULL || p_article == NULL)
        {
                log_error("section_data_append_article() NULL pointer error\n");
                return -1;
        }

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

        if (p_section->p_tail_block == NULL || p_section->p_tail_block->article_count >= BBS_article_limit_per_block)
        {
                if (p_section->block_count >= BBS_article_block_limit_per_section)
                {
                        log_error("section block count %d reach limit\n", p_section->block_count);
                        return -2;
                }

                if ((p_block = pop_free_article_block()) == NULL)
                {
                        log_error("pop_free_article_block() error\n");
                        return -2;
                }

                p_block->article_count = 0;
                p_block->p_next_block = NULL;

                if (p_section->p_tail_block == NULL)
                {
                        p_section->p_head_block = p_block;
                        last_aid = 0;
                }
                else
                {
                        p_section->p_tail_block->p_next_block = p_block;
                        last_aid = p_section->p_tail_block->articles[BBS_article_limit_per_block - 1].aid;
                }
                p_section->p_tail_block = p_block;
                p_section->p_block[p_section->block_count] = p_block;
                p_section->block_count++;
        }
        else
        {
                p_block = p_section->p_tail_block;
                last_aid = p_block->articles[p_block->article_count - 1].aid;
        }

        // AID of articles should be strictly ascending
        if (p_article->aid <= last_aid)
        {
                log_error("section_data_append_article(aid=%d) error: last_aid=%d\n", p_article->aid, last_aid);
                return -3;
        }

        if (p_block->article_count == 0)
        {
                p_section->block_head_aid[p_section->block_count - 1] = p_article->aid;
        }

        if (p_article->tid != 0)
        {
                p_topic_head = section_data_find_article_by_aid(p_section, p_article->tid);
                if (p_topic_head == NULL)
                {
                        log_error("search head of topic (aid=%d) error\n", p_article->tid);
                        return -4;
                }

                p_topic_tail = section_data_find_article_by_aid(p_section, p_topic_head->prior_aid);
                if (p_topic_tail == NULL)
                {
                        log_error("search tail of topic (aid=%d) error\n", p_topic_head->prior_aid);
                        return -4;
                }
        }
        else
        {
                p_topic_head = &(p_block->articles[p_block->article_count]);
                p_topic_tail = p_topic_head;
        }

        // Copy article data
        p_block->articles[p_block->article_count] = *p_article;

        // Link appended article as tail node of topic bi-directional list;
        p_block->articles[p_block->article_count].prior_aid = p_topic_tail->aid;
        p_block->articles[p_block->article_count].next_aid = p_topic_head->aid;
        p_topic_head->prior_aid = p_article->aid;
        p_topic_tail->next_aid = p_article->aid;

        p_block->article_count++;
        p_section->article_count++;

        return 0;
}

ARTICLE *section_data_find_article_by_aid(SECTION_DATA *p_section, int32_t aid)
{
        ARTICLE *p_article;
        ARTICLE_BLOCK *p_block;
        int left;
        int right;
        int mid;

        if (p_section == NULL)
        {
                log_error("section_data_find_article_by_aid() NULL pointer error\n");
                return NULL;
        }

        if (p_section->block_count == 0) // empty section
        {
                return NULL;
        }

        left = 0;
        right = p_section->block_count;

        // aid in the range [ head aid of blocks[left], tail aid of blocks[right - 1] ]
        while (left < right - 1)
        {
                // get block offset no less than mid value of left and right block offsets
                mid = (left + right) / 2 + (right - left) % 2;
                
                if (mid >= BBS_article_block_limit_per_section)
                {
                        log_error("block_m(%d) is out of boundary\n", mid);
                        return NULL;
                }

                if (aid < p_section->block_head_aid[mid])
                {
                        right = mid;
                }
                else
                {
                        left = mid;
                }
        }

        p_block = p_section->p_block[left];

        left = 0;
        right = p_block->article_count - 1;

        // aid in the range [ aid of articles[left], aid of articles[right] ]
        while (left < right)
        {
                mid = (left + right) / 2;

                if (aid <= p_block->articles[mid].aid)
                {
                        right = mid;
                }
                else
                {
                        left = mid + 1;
                }
        }

        p_article = &(p_block->articles[left]);

        return p_article;
}

ARTICLE *section_data_find_article_by_index(SECTION_DATA *p_section, int index)
{
        ARTICLE *p_article;
        ARTICLE_BLOCK *p_block;

        if (p_section == NULL)
        {
                log_error("section_data_find_article_by_index() NULL pointer error\n");
                return NULL;
        }

        if (index < 0 || index >= p_section->article_count)
        {
                log_error("section_data_find_article_by_index(%d) is out of boundary [0, %d)\n", index, p_section->article_count);
                return NULL;
        }

        p_block = p_section->p_block[index / BBS_article_limit_per_block];
        p_article = &(p_block->articles[index % BBS_article_limit_per_block]);

        return p_article;
}

int section_data_mark_del_article(SECTION_DATA *p_section, int32_t aid)
{
        ARTICLE *p_article;

        if (p_section == NULL)
        {
                log_error("section_data_mark_del_article() NULL pointer error\n");
                return -2;
        }

        p_article = section_data_find_article_by_aid(p_section, aid);
        if (p_article == NULL)
        {
                return -1; // Not found
        }

        if (p_article->visible == 0)
        {
                return 0; // Already deleted
        }

        p_article->visible = 0;
        p_section->delete_count++;

        return 1;
}
1	sysadm	1.1	/***************************************************************************
2			section_list.c - description
3			-------------------
4			Copyright : (C) 2004-2025 by Leaflet
5			Email : leaflet@leafok.com
6			***************************************************************************/
7
8			/***************************************************************************
9			* *
10			* This program is free software; you can redistribute it and/or modify *
11			* it under the terms of the GNU General Public License as published by *
12			* the Free Software Foundation; either version 3 of the License, or *
13			* (at your option) any later version. *
14			* *
15			***************************************************************************/
16
17			#include "section_list.h"
18			#include "log.h"
19			#include "io.h"
20			#include "trie_dict.h"
21			#include <stdio.h>
22			#include <string.h>
23			#include <signal.h>
24			#include <unistd.h>
25			#include <stdlib.h>
26			#include <errno.h>
27			#include <sys/shm.h>
28			#include <sys/ipc.h>
29
30			#define ARTICLE_BLOCK_PER_SHM 50 // sizeof(ARTICLE_BLOCK) * ARTICLE_BLOCK_PER_SHM is the size of each shm segment to allocate
31			#define ARTICLE_BLOCK_SHM_COUNT_LIMIT 256
32
33			struct article_block_shm_t
34			{
35			int shmid;
36			void *p_shm;
37			};
38			typedef struct article_block_shm_t ARTICLE_BLOCK_SHM;
39
40			static ARTICLE_BLOCK_SHM *p_article_block_shm_pool;
41			static int article_block_shm_count;
42			static ARTICLE_BLOCK *p_article_block_free_list;
43
44			static SECTION_DATA *p_section_data_pool;
45			static int section_data_count;
46			static TRIE_NODE *p_trie_dict_section_data;
47
48			int section_data_pool_init(const char *filename, int article_block_count)
49			{
50			int shmid;
51			int proj_id;
52			key_t key;
53			size_t size;
54			void *p_shm;
55			int i;
56			int article_block_count_in_shm;
57			ARTICLE_BLOCK *p_article_block_in_shm;
58			ARTICLE_BLOCK **pp_article_block_next;
59
60			if (p_article_block_shm_pool != NULL \|\|
61			p_article_block_free_list != NULL \|\|
62			p_section_data_pool != NULL \|\|
63			p_trie_dict_section_data != NULL)
64			{
65			log_error("section_data_pool already initialized\n");
66			return -1;
67			}
68
69			if (article_block_count > ARTICLE_BLOCK_PER_SHM * ARTICLE_BLOCK_SHM_COUNT_LIMIT)
70			{
71			log_error("article_block_count exceed limit %d\n", ARTICLE_BLOCK_PER_SHM * ARTICLE_BLOCK_SHM_COUNT_LIMIT);
72			return -2;
73			}
74
75			p_article_block_shm_pool = calloc((size_t)article_block_count / ARTICLE_BLOCK_PER_SHM + 1, sizeof(ARTICLE_BLOCK_SHM));
76			if (p_article_block_shm_pool == NULL)
77			{
78			log_error("calloc(%d ARTICLE_BLOCK_SHM) OOM\n", article_block_count / ARTICLE_BLOCK_PER_SHM + 1);
79			return -2;
80			}
81
82			p_section_data_pool = calloc(BBS_max_section, sizeof(SECTION_DATA));
83			if (p_section_data_pool == NULL)
84			{
85			log_error("calloc(%d SECTION_DATA) OOM\n", BBS_max_section);
86			return -2;
87			}
88			section_data_count = 0;
89
90			p_trie_dict_section_data = trie_dict_create();
91			if (p_trie_dict_section_data == NULL)
92			{
93			log_error("trie_dict_create() OOM\n", BBS_max_section);
94			return -2;
95			}
96
97			// Allocate shared memory
98			article_block_shm_count = 0;
99			pp_article_block_next = &p_article_block_free_list;
100
101			while (article_block_count > 0)
102			{
103			article_block_count_in_shm =
104			(article_block_count < ARTICLE_BLOCK_PER_SHM ? article_block_count : ARTICLE_BLOCK_PER_SHM);
105			article_block_count -= article_block_count_in_shm;
106
107			proj_id = getpid() + article_block_shm_count;
108			key = ftok(filename, proj_id);
109			if (key == -1)
110			{
111			log_error("ftok(%s, %d) error (%d)\n", filename, proj_id, errno);
112			section_data_pool_cleanup();
113			return -3;
114			}
115
116			size = sizeof(shmid) + sizeof(ARTICLE_BLOCK) * (size_t)article_block_count_in_shm;
117			shmid = shmget(key, size, IPC_CREAT \| IPC_EXCL \| 0600);
118			if (shmid == -1)
119			{
120			log_error("shmget(shm_index = %d, size = %d) error (%d)\n", article_block_shm_count, size, errno);
121			section_data_pool_cleanup();
122			return -3;
123			}
124			p_shm = shmat(shmid, NULL, 0);
125			if (p_shm == (void *)-1)
126			{
127			log_error("shmat(shmid = %d) error (%d)\n", shmid, errno);
128			section_data_pool_cleanup();
129			return -3;
130			}
131
132			(p_article_block_shm_pool + article_block_shm_count)->shmid = shmid;
133			(p_article_block_shm_pool + article_block_shm_count)->p_shm = p_shm;
134			article_block_shm_count++;
135
136			p_article_block_in_shm = p_shm;
137			*pp_article_block_next = p_article_block_in_shm;
138
139			for (i = 0; i < article_block_count_in_shm; i++)
140			{
141			if (i < article_block_count_in_shm - 1)
142			{
143			(p_article_block_in_shm + i)->p_next_block = (p_article_block_in_shm + i + 1);
144			}
145			else
146			{
147			(p_article_block_in_shm + i)->p_next_block = NULL;
148			pp_article_block_next = &((p_article_block_in_shm + i)->p_next_block);
149			}
150			}
151			}
152
153			return 0;
154			}
155
156			void section_data_pool_cleanup(void)
157			{
158			int i;
159
160			if (p_trie_dict_section_data != NULL)
161			{
162			trie_dict_destroy(p_trie_dict_section_data);
163			p_trie_dict_section_data = NULL;
164			section_data_count = 0;
165			}
166
167			if (p_section_data_pool != NULL)
168			{
169			free(p_section_data_pool);
170			p_section_data_pool = NULL;
171			}
172
173			if (p_article_block_free_list != NULL)
174			{
175			p_article_block_free_list = NULL;
176			}
177
178			if (p_article_block_shm_pool != NULL)
179			{
180			for (i = 0; i < article_block_shm_count; i++)
181			{
182			if (shmdt((p_article_block_shm_pool + i)->p_shm) == -1)
183			{
184			log_error("shmdt(shmid = %d) error (%d)\n", (p_article_block_shm_pool + i)->shmid, errno);
185			}
186
187			if (shmctl((p_article_block_shm_pool + i)->shmid, IPC_RMID, NULL) == -1)
188			{
189			log_error("shmctl(shmid = %d, IPC_RMID) error (%d)\n", (p_article_block_shm_pool + i)->shmid, errno);
190			}
191			}
192
193			p_article_block_shm_pool = NULL;
194			article_block_shm_count = 0;
195			}
196			}
197
198			inline static ARTICLE_BLOCK *pop_free_article_block(void)
199			{
200			ARTICLE_BLOCK *p_article_block = NULL;
201
202			if (p_article_block_free_list != NULL)
203			{
204			p_article_block = p_article_block_free_list;
205			p_article_block_free_list = p_article_block_free_list->p_next_block;
206			}
207
208			return p_article_block;
209			}
210
211			inline static void push_free_article_block(ARTICLE_BLOCK *p_article_block)
212			{
213			p_article_block->p_next_block = p_article_block_free_list;
214			p_article_block_free_list = p_article_block;
215			}
216
217			SECTION_DATA section_data_create(const char sname, const char stitle, const char master_name)
218			{
219			SECTION_DATA *p_section;
220			int index;
221
222			if (p_section_data_pool == NULL \|\| p_trie_dict_section_data == NULL)
223			{
224			log_error("section_data not initialized\n");
225			return NULL;
226			}
227
228			if (section_data_count >= BBS_max_section)
229			{
230			log_error("section_data_count exceed limit %d\n", BBS_max_section);
231			return NULL;
232			}
233
234			index = section_data_count;
235			p_section = p_section_data_pool + index;
236
237			strncpy(p_section->sname, sname, sizeof(p_section->sname - 1));
238			p_section->sname[sizeof(p_section->sname - 1)] = '\0';
239
240			strncpy(p_section->stitle, stitle, sizeof(p_section->stitle - 1));
241			p_section->stitle[sizeof(p_section->stitle - 1)] = '\0';
242
243			strncpy(p_section->master_name, master_name, sizeof(p_section->master_name - 1));
244			p_section->master_name[sizeof(p_section->master_name - 1)] = '\0';
245
246			p_section->p_head_block = NULL;
247			p_section->p_tail_block = NULL;
248			p_section->block_count = 0;
249			p_section->article_count = 0;
250			p_section->delete_count = 0;
251
252			if (trie_dict_set(p_trie_dict_section_data, sname, index) != 1)
253			{
254			log_error("trie_dict_set(section_data, %s, %d) error\n", sname, index);
255			return NULL;
256			}
257
258			section_data_count++;
259
260			return p_section;
261			}
262
263			int section_data_free_block(SECTION_DATA *p_section)
264			{
265			ARTICLE_BLOCK *p_block;
266
267			if (p_section == NULL)
268			{
269			log_error("section_data_free_block() NULL pointer error\n");
270			return -1;
271			}
272
273			if (p_section_data_pool == NULL)
274			{
275			log_error("section_data not initialized\n");
276			return -1;
277			}
278
279			while (p_section->p_head_block != NULL)
280			{
281			p_block = p_section->p_head_block;
282			p_section->p_head_block = p_block->p_next_block;
283			push_free_article_block(p_block);
284			}
285
286			p_section->p_tail_block = NULL;
287			p_section->block_count = 0;
288			p_section->article_count = 0;
289			p_section->delete_count = 0;
290
291			return 0;
292			}
293
294			SECTION_DATA section_data_find_by_name(const char sname)
295			{
296			int64_t index;
297
298			if (p_section_data_pool == NULL \|\| p_trie_dict_section_data == NULL)
299			{
300			log_error("section_data not initialized\n");
301			return NULL;
302			}
303
304			if (trie_dict_get(p_trie_dict_section_data, sname, &index) != 1)
305			{
306			log_error("trie_dict_get(section_data, %s) error\n", sname);
307			return NULL;
308			}
309
310			return (p_section_data_pool + index);
311			}
312
313			int section_data_append_article(SECTION_DATA p_section, const ARTICLE p_article)
314			{
315			ARTICLE_BLOCK *p_block;
316			int32_t last_aid = 0;
317			ARTICLE *p_topic_head;
318			ARTICLE *p_topic_tail;
319
320			if (p_section == NULL \|\| p_article == NULL)
321			{
322			log_error("section_data_append_article() NULL pointer error\n");
323			return -1;
324			}
325
326			if (p_section_data_pool == NULL)
327			{
328			log_error("section_data not initialized\n");
329			return -1;
330			}
331
332			if (p_section->p_tail_block == NULL \|\| p_section->p_tail_block->article_count >= BBS_article_limit_per_block)
333			{
334			if (p_section->block_count >= BBS_article_block_limit_per_section)
335			{
336			log_error("section block count %d reach limit\n", p_section->block_count);
337			return -2;
338			}
339
340			if ((p_block = pop_free_article_block()) == NULL)
341			{
342			log_error("pop_free_article_block() error\n");
343			return -2;
344			}
345
346			p_block->article_count = 0;
347			p_block->p_next_block = NULL;
348
349			if (p_section->p_tail_block == NULL)
350			{
351			p_section->p_head_block = p_block;
352			last_aid = 0;
353			}
354			else
355			{
356			p_section->p_tail_block->p_next_block = p_block;
357			last_aid = p_section->p_tail_block->articles[BBS_article_limit_per_block - 1].aid;
358			}
359			p_section->p_tail_block = p_block;
360			p_section->p_block[p_section->block_count] = p_block;
361			p_section->block_count++;
362			}
363			else
364			{
365			p_block = p_section->p_tail_block;
366			last_aid = p_block->articles[p_block->article_count - 1].aid;
367			}
368
369			// AID of articles should be strictly ascending
370			if (p_article->aid <= last_aid)
371			{
372			log_error("section_data_append_article(aid=%d) error: last_aid=%d\n", p_article->aid, last_aid);
373			return -3;
374			}
375
376			if (p_block->article_count == 0)
377			{
378			p_section->block_head_aid[p_section->block_count - 1] = p_article->aid;
379			}
380
381			if (p_article->tid != 0)
382			{
383	sysadm	1.2	p_topic_head = section_data_find_article_by_aid(p_section, p_article->tid);
384	sysadm	1.1	if (p_topic_head == NULL)
385			{
386			log_error("search head of topic (aid=%d) error\n", p_article->tid);
387			return -4;
388			}
389
390	sysadm	1.2	p_topic_tail = section_data_find_article_by_aid(p_section, p_topic_head->prior_aid);
391	sysadm	1.1	if (p_topic_tail == NULL)
392			{
393			log_error("search tail of topic (aid=%d) error\n", p_topic_head->prior_aid);
394			return -4;
395			}
396			}
397			else
398			{
399			p_topic_head = &(p_block->articles[p_block->article_count]);
400			p_topic_tail = p_topic_head;
401			}
402
403			// Copy article data
404			p_block->articles[p_block->article_count] = *p_article;
405
406			// Link appended article as tail node of topic bi-directional list;
407			p_block->articles[p_block->article_count].prior_aid = p_topic_tail->aid;
408			p_block->articles[p_block->article_count].next_aid = p_topic_head->aid;
409			p_topic_head->prior_aid = p_article->aid;
410			p_topic_tail->next_aid = p_article->aid;
411
412			p_block->article_count++;
413			p_section->article_count++;
414
415			return 0;
416			}
417
418	sysadm	1.2	ARTICLE section_data_find_article_by_aid(SECTION_DATA p_section, int32_t aid)
419	sysadm	1.1	{
420			ARTICLE *p_article;
421			ARTICLE_BLOCK *p_block;
422			int left;
423			int right;
424			int mid;
425
426			if (p_section == NULL)
427			{
428	sysadm	1.2	log_error("section_data_find_article_by_aid() NULL pointer error\n");
429	sysadm	1.1	return NULL;
430			}
431
432			if (p_section->block_count == 0) // empty section
433			{
434			return NULL;
435			}
436
437			left = 0;
438			right = p_section->block_count;
439
440			// aid in the range [ head aid of blocks[left], tail aid of blocks[right - 1] ]
441			while (left < right - 1)
442			{
443			// get block offset no less than mid value of left and right block offsets
444			mid = (left + right) / 2 + (right - left) % 2;
445
446			if (mid >= BBS_article_block_limit_per_section)
447			{
448			log_error("block_m(%d) is out of boundary\n", mid);
449			return NULL;
450			}
451
452			if (aid < p_section->block_head_aid[mid])
453			{
454			right = mid;
455			}
456			else
457			{
458			left = mid;
459			}
460			}
461
462			p_block = p_section->p_block[left];
463
464			left = 0;
465			right = p_block->article_count - 1;
466
467			// aid in the range [ aid of articles[left], aid of articles[right] ]
468			while (left < right)
469			{
470			mid = (left + right) / 2;
471
472			if (aid <= p_block->articles[mid].aid)
473			{
474			right = mid;
475			}
476			else
477			{
478			left = mid + 1;
479			}
480			}
481
482			p_article = &(p_block->articles[left]);
483
484			return p_article;
485			}
486
487	sysadm	1.2	ARTICLE section_data_find_article_by_index(SECTION_DATA p_section, int index)
488			{
489			ARTICLE *p_article;
490			ARTICLE_BLOCK *p_block;
491
492			if (p_section == NULL)
493			{
494			log_error("section_data_find_article_by_index() NULL pointer error\n");
495			return NULL;
496			}
497
498			if (index < 0 \|\| index >= p_section->article_count)
499			{
500			log_error("section_data_find_article_by_index(%d) is out of boundary [0, %d)\n", index, p_section->article_count);
501			return NULL;
502			}
503
504			p_block = p_section->p_block[index / BBS_article_limit_per_block];
505			p_article = &(p_block->articles[index % BBS_article_limit_per_block]);
506
507			return p_article;
508			}
509
510	sysadm	1.1	int section_data_mark_del_article(SECTION_DATA *p_section, int32_t aid)
511			{
512			ARTICLE *p_article;
513
514	sysadm	1.2	if (p_section == NULL)
515			{
516			log_error("section_data_mark_del_article() NULL pointer error\n");
517			return -2;
518			}
519
520			p_article = section_data_find_article_by_aid(p_section, aid);
521	sysadm	1.1	if (p_article == NULL)
522			{
523			return -1; // Not found
524			}
525
526			if (p_article->visible == 0)
527			{
528			return 0; // Already deleted
529			}
530
531			p_article->visible = 0;
532			p_section->delete_count++;
533
534			return 1;
535			}
webmaster@leafok.com	ViewVC Help
Powered by ViewVC 1.3.0-beta1