2 * Copyright (C) 1994-1996, Index Data I/S
4 * Sebastian Hammer, Adam Dickmeiss
7 * Revision 1.20 1996-12-23 15:30:44 adam
9 * Bug fix: result sets weren't deleted after server shut down.
11 * Revision 1.19 1996/12/11 12:08:00 adam
12 * Added better compression.
14 * Revision 1.18 1996/10/29 14:09:44 adam
15 * Use of cisam system - enabled if setting isamc is 1.
17 * Revision 1.17 1996/06/04 10:18:58 adam
18 * Minor changes - removed include of ctype.h.
20 * Revision 1.16 1996/05/13 14:23:05 adam
21 * Work on compaction of set/use bytes in dictionary.
23 * Revision 1.15 1995/11/20 16:59:46 adam
24 * New update method: the 'old' keys are saved for each records.
26 * Revision 1.14 1995/10/30 15:08:08 adam
29 * Revision 1.13 1995/10/27 14:00:11 adam
30 * Implemented detection of database availability.
32 * Revision 1.12 1995/10/17 18:02:08 adam
33 * New feature: databases. Implemented as prefix to words in dictionary.
35 * Revision 1.11 1995/10/06 16:33:37 adam
36 * Use attribute mappings.
38 * Revision 1.10 1995/09/29 14:01:41 adam
41 * Revision 1.9 1995/09/28 12:10:32 adam
42 * Bug fixes. Field prefix used in queries.
44 * Revision 1.8 1995/09/28 09:19:42 adam
45 * xfree/xmalloc used everywhere.
46 * Extract/retrieve method seems to work for text records.
48 * Revision 1.7 1995/09/27 12:22:28 adam
49 * More work on extract in record control.
50 * Field name is not in isam keys but in prefix in dictionary words.
52 * Revision 1.6 1995/09/14 07:48:23 adam
53 * Record control management.
55 * Revision 1.5 1995/09/11 13:09:34 adam
56 * More work on relevance feedback.
58 * Revision 1.4 1995/09/08 14:52:27 adam
59 * Minor changes. Dictionary is lower case now.
61 * Revision 1.3 1995/09/07 13:58:36 adam
62 * New parameter: result-set file descriptor (RSFD) to support multiple
63 * positions within the same result-set.
64 * Boolean operators: and, or, not implemented.
65 * Result-set references.
67 * Revision 1.2 1995/09/06 16:11:17 adam
68 * Option: only one word key per file.
70 * Revision 1.1 1995/09/04 09:10:36 adam
71 * More work on index add/del/update.
72 * Merge sort implemented.
73 * Initial work on z39 server.
84 void key_logdump (int logmask, const void *p)
88 memcpy (&key, p, sizeof(key));
89 logf (logmask, "%7d s=%-4d", key.sysno, key.seqno);
92 int key_compare_it (const void *p1, const void *p2)
94 if (((struct it_key *) p1)->sysno != ((struct it_key *) p2)->sysno)
96 if (((struct it_key *) p1)->sysno > ((struct it_key *) p2)->sysno)
101 if (((struct it_key *) p1)->seqno != ((struct it_key *) p2)->seqno)
103 if (((struct it_key *) p1)->seqno > ((struct it_key *) p2)->seqno)
111 int key_compare (const void *p1, const void *p2)
113 struct it_key i1, i2;
114 memcpy (&i1, p1, sizeof(i1));
115 memcpy (&i2, p2, sizeof(i2));
116 if (i1.sysno != i2.sysno)
118 if (i1.sysno > i2.sysno)
123 if (i1.seqno != i2.seqno)
125 if (i1.seqno > i2.seqno)
133 int key_qsort_compare (const void *p1, const void *p2)
137 char *cp1 = *(char **) p1;
138 char *cp2 = *(char **) p2;
140 if ((r = strcmp (cp1, cp2)))
143 if ((r = key_compare (cp1+l+1, cp2+l+1)))
145 return cp1[l] - cp2[l];
148 struct iscz1_code_info {
152 static void *iscz1_code_start (int mode)
154 struct iscz1_code_info *p = xmalloc (sizeof(*p));
160 static void iscz1_code_stop (int mode, void *p)
165 void iscz1_encode_int (unsigned d, char **dst)
167 unsigned char *bp = (unsigned char*) *dst;
176 else if (d <= 4194303)
178 *bp++ = 128 + (d>>16);
179 *bp++ = (d>>8) & 255;
184 *bp++ = 192 + (d>>24);
185 *bp++ = (d>>16) & 255;
186 *bp++ = (d>>8) & 255;
192 int iscz1_decode_int (unsigned char **src)
194 unsigned c = *(*src)++;
200 return ((c & 63) << 8) + *(*src)++;
202 c = ((c & 63) << 8) + *(*src)++;
203 c = (c << 8) + *(*src)++;
206 c = ((c & 63) << 8) + *(*src)++;
207 c = (c << 8) + *(*src)++;
208 c = (c << 8) + *(*src)++;
212 static void iscz1_code_item (int mode, void *vp, char **dst, char **src)
214 struct iscz1_code_info *p = vp;
218 if (mode == ISAMC_ENCODE)
220 memcpy (&tkey, *src, sizeof(struct it_key));
221 d = tkey.sysno - p->key.sysno;
224 iscz1_encode_int (2*tkey.seqno + 1, dst);
225 iscz1_encode_int (d, dst);
227 p->key.seqno = tkey.seqno;
231 iscz1_encode_int (2*(tkey.seqno - p->key.seqno), dst);
232 p->key.seqno = tkey.seqno;
234 (*src) += sizeof(struct it_key);
238 d = iscz1_decode_int ((unsigned char **) src);
242 p->key.sysno += iscz1_decode_int ((unsigned char **) src);
245 p->key.seqno += d>>1;
246 memcpy (*dst, &p->key, sizeof(struct it_key));
247 (*dst) += sizeof(struct it_key);
251 ISAMC_M key_isamc_m (void)
253 static ISAMC_M me = NULL;
258 me = isc_getmethod ();
260 me->compare_item = key_compare;
262 me->code_start = iscz1_code_start;
263 me->code_item = iscz1_code_item;
264 me->code_stop = iscz1_code_stop;
266 me->debug = atoi(res_get_def (common_resource, "isamcDebug", "0"));
268 logf (LOG_LOG, "ISAMC system active");