/*
- * Copyright (C) 1995, Index Data I/S
+ * Copyright (C) 1994-1996, Index Data I/S
* All rights reserved.
* Sebastian Hammer, Adam Dickmeiss
*
* $Log: kcompare.c,v $
- * Revision 1.1 1995-09-04 09:10:36 adam
+ * Revision 1.20 1996-12-23 15:30:44 adam
+ * Work on truncation.
+ * Bug fix: result sets weren't deleted after server shut down.
+ *
+ * Revision 1.19 1996/12/11 12:08:00 adam
+ * Added better compression.
+ *
+ * Revision 1.18 1996/10/29 14:09:44 adam
+ * Use of cisam system - enabled if setting isamc is 1.
+ *
+ * Revision 1.17 1996/06/04 10:18:58 adam
+ * Minor changes - removed include of ctype.h.
+ *
+ * Revision 1.16 1996/05/13 14:23:05 adam
+ * Work on compaction of set/use bytes in dictionary.
+ *
+ * Revision 1.15 1995/11/20 16:59:46 adam
+ * New update method: the 'old' keys are saved for each records.
+ *
+ * Revision 1.14 1995/10/30 15:08:08 adam
+ * Bug fixes.
+ *
+ * Revision 1.13 1995/10/27 14:00:11 adam
+ * Implemented detection of database availability.
+ *
+ * Revision 1.12 1995/10/17 18:02:08 adam
+ * New feature: databases. Implemented as prefix to words in dictionary.
+ *
+ * Revision 1.11 1995/10/06 16:33:37 adam
+ * Use attribute mappings.
+ *
+ * Revision 1.10 1995/09/29 14:01:41 adam
+ * Bug fixes.
+ *
+ * Revision 1.9 1995/09/28 12:10:32 adam
+ * Bug fixes. Field prefix used in queries.
+ *
+ * Revision 1.8 1995/09/28 09:19:42 adam
+ * xfree/xmalloc used everywhere.
+ * Extract/retrieve method seems to work for text records.
+ *
+ * Revision 1.7 1995/09/27 12:22:28 adam
+ * More work on extract in record control.
+ * Field name is not in isam keys but in prefix in dictionary words.
+ *
+ * Revision 1.6 1995/09/14 07:48:23 adam
+ * Record control management.
+ *
+ * Revision 1.5 1995/09/11 13:09:34 adam
+ * More work on relevance feedback.
+ *
+ * Revision 1.4 1995/09/08 14:52:27 adam
+ * Minor changes. Dictionary is lower case now.
+ *
+ * Revision 1.3 1995/09/07 13:58:36 adam
+ * New parameter: result-set file descriptor (RSFD) to support multiple
+ * positions within the same result-set.
+ * Boolean operators: and, or, not implemented.
+ * Result-set references.
+ *
+ * Revision 1.2 1995/09/06 16:11:17 adam
+ * Option: only one word key per file.
+ *
+ * Revision 1.1 1995/09/04 09:10:36 adam
* More work on index add/del/update.
* Merge sort implemented.
* Initial work on z39 server.
#include "index.h"
+void key_logdump (int logmask, const void *p)
+{
+ struct it_key key;
+
+ memcpy (&key, p, sizeof(key));
+ logf (logmask, "%7d s=%-4d", key.sysno, key.seqno);
+}
+
+int key_compare_it (const void *p1, const void *p2)
+{
+ if (((struct it_key *) p1)->sysno != ((struct it_key *) p2)->sysno)
+ {
+ if (((struct it_key *) p1)->sysno > ((struct it_key *) p2)->sysno)
+ return 2;
+ else
+ return -2;
+ }
+ if (((struct it_key *) p1)->seqno != ((struct it_key *) p2)->seqno)
+ {
+ if (((struct it_key *) p1)->seqno > ((struct it_key *) p2)->seqno)
+ return 1;
+ else
+ return -1;
+ }
+ return 0;
+}
+
int key_compare (const void *p1, const void *p2)
{
struct it_key i1, i2;
memcpy (&i1, p1, sizeof(i1));
memcpy (&i2, p2, sizeof(i2));
- if ( i1.sysno != i2.sysno)
- return i1.sysno - i2.sysno;
- if ( i1.seqno != i2.seqno)
- return i1.seqno - i2.seqno;
- return i1.field - i2.field;
+ if (i1.sysno != i2.sysno)
+ {
+ if (i1.sysno > i2.sysno)
+ return 2;
+ else
+ return -2;
+ }
+ if (i1.seqno != i2.seqno)
+ {
+ if (i1.seqno > i2.seqno)
+ return 1;
+ else
+ return -1;
+ }
+ return 0;
}
-int key_compare_x (const struct it_key *i1, const struct it_key *i2)
+int key_qsort_compare (const void *p1, const void *p2)
{
- if ( i1->sysno != i2->sysno)
- return i1->sysno - i2->sysno;
- if ( i1->seqno != i2->seqno)
- return i1->seqno - i2->seqno;
- return i1->field - i2->field;
+ int r;
+ size_t l;
+ char *cp1 = *(char **) p1;
+ char *cp2 = *(char **) p2;
+
+ if ((r = strcmp (cp1, cp2)))
+ return r;
+ l = strlen(cp1)+1;
+ if ((r = key_compare (cp1+l+1, cp2+l+1)))
+ return r;
+ return cp1[l] - cp2[l];
+}
+
+struct iscz1_code_info {
+ struct it_key key;
+};
+
+static void *iscz1_code_start (int mode)
+{
+ struct iscz1_code_info *p = xmalloc (sizeof(*p));
+ p->key.sysno = 0;
+ p->key.seqno = 0;
+ return p;
+}
+
+static void iscz1_code_stop (int mode, void *p)
+{
+ xfree (p);
+}
+
+void iscz1_encode_int (unsigned d, char **dst)
+{
+ unsigned char *bp = (unsigned char*) *dst;
+
+ if (d <= 63)
+ *bp++ = d;
+ else if (d <= 16383)
+ {
+ *bp++ = 64 + (d>>8);
+ *bp++ = d & 255;
+ }
+ else if (d <= 4194303)
+ {
+ *bp++ = 128 + (d>>16);
+ *bp++ = (d>>8) & 255;
+ *bp++ = d & 255;
+ }
+ else
+ {
+ *bp++ = 192 + (d>>24);
+ *bp++ = (d>>16) & 255;
+ *bp++ = (d>>8) & 255;
+ *bp++ = d & 255;
+ }
+ *dst = (char *) bp;
+}
+
+int iscz1_decode_int (unsigned char **src)
+{
+ unsigned c = *(*src)++;
+ switch (c & 192)
+ {
+ case 0:
+ return c;
+ case 64:
+ return ((c & 63) << 8) + *(*src)++;
+ case 128:
+ c = ((c & 63) << 8) + *(*src)++;
+ c = (c << 8) + *(*src)++;
+ return c;
+ }
+ c = ((c & 63) << 8) + *(*src)++;
+ c = (c << 8) + *(*src)++;
+ c = (c << 8) + *(*src)++;
+ return c;
+}
+
+static void iscz1_code_item (int mode, void *vp, char **dst, char **src)
+{
+ struct iscz1_code_info *p = vp;
+ struct it_key tkey;
+ int d;
+
+ if (mode == ISAMC_ENCODE)
+ {
+ memcpy (&tkey, *src, sizeof(struct it_key));
+ d = tkey.sysno - p->key.sysno;
+ if (d)
+ {
+ iscz1_encode_int (2*tkey.seqno + 1, dst);
+ iscz1_encode_int (d, dst);
+ p->key.sysno += d;
+ p->key.seqno = tkey.seqno;
+ }
+ else
+ {
+ iscz1_encode_int (2*(tkey.seqno - p->key.seqno), dst);
+ p->key.seqno = tkey.seqno;
+ }
+ (*src) += sizeof(struct it_key);
+ }
+ else
+ {
+ d = iscz1_decode_int ((unsigned char **) src);
+ if (d & 1)
+ {
+ p->key.seqno = d>>1;
+ p->key.sysno += iscz1_decode_int ((unsigned char **) src);
+ }
+ else
+ p->key.seqno += d>>1;
+ memcpy (*dst, &p->key, sizeof(struct it_key));
+ (*dst) += sizeof(struct it_key);
+ }
+}
+
+ISAMC_M key_isamc_m (void)
+{
+ static ISAMC_M me = NULL;
+
+ if (me)
+ return me;
+
+ me = isc_getmethod ();
+
+ me->compare_item = key_compare;
+
+ me->code_start = iscz1_code_start;
+ me->code_item = iscz1_code_item;
+ me->code_stop = iscz1_code_stop;
+
+ me->debug = atoi(res_get_def (common_resource, "isamcDebug", "0"));
+
+ logf (LOG_LOG, "ISAMC system active");
+ return me;
}