* Sebastian Hammer, Adam Dickmeiss
*
* $Log: kcompare.c,v $
- * Revision 1.18 1996-10-29 14:09:44 adam
+ * 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
return cp1[l] - cp2[l];
}
-struct iscz_code_info {
+struct iscz1_code_info {
struct it_key key;
};
-static void *iscz_code_start (int mode)
+static void *iscz1_code_start (int mode)
{
- struct iscz_code_info *p = xmalloc (sizeof(*p));
+ struct iscz1_code_info *p = xmalloc (sizeof(*p));
p->key.sysno = 0;
p->key.seqno = 0;
return p;
}
-static void iscz_code_stop (int mode, void *p)
+static void iscz1_code_stop (int mode, void *p)
{
xfree (p);
}
-void iscz_encode_int (unsigned d, char **dst)
+void iscz1_encode_int (unsigned d, char **dst)
{
unsigned char *bp = (unsigned char*) *dst;
*dst = (char *) bp;
}
-int isxz_decode_int (unsigned char **src)
+int iscz1_decode_int (unsigned char **src)
{
unsigned c = *(*src)++;
switch (c & 192)
c = (c << 8) + *(*src)++;
return c;
}
+#if 1
+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;
-static void iscz_code_item (int mode, void *vp, char **dst, char **src)
+ 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);
+ }
+}
+#else
+static void iscz1_code_item (int mode, void *vp, char **dst, char **src)
{
- struct iscz_code_info *p = vp;
+ struct iscz1_code_info *p = vp;
struct it_key tkey;
int d;
{
memcpy (&tkey, *src, sizeof(struct it_key));
d = tkey.sysno - p->key.sysno;
- iscz_encode_int (d, dst);
+ iscz1_encode_int (d, dst);
if (d)
{
p->key.sysno = tkey.sysno;
p->key.seqno = 0;
}
- iscz_encode_int (tkey.seqno - p->key.seqno, dst);
+ iscz1_encode_int (tkey.seqno - p->key.seqno, dst);
p->key.seqno = tkey.seqno;
(*src) += sizeof(struct it_key);
}
else
{
- d = isxz_decode_int ((unsigned char **) src);
+ d = iscz1_decode_int ((unsigned char **) src);
if (d)
{
p->key.sysno += d;
p->key.seqno = 0;
}
- d = isxz_decode_int ((unsigned char **) src);
+ d = iscz1_decode_int ((unsigned char **) src);
p->key.seqno += d;
memcpy (*dst, &p->key, sizeof(struct it_key));
(*dst) += sizeof(struct it_key);
}
}
+#endif
ISAMC_M key_isamc_m (void)
{
me->compare_item = key_compare;
- me->code_start = iscz_code_start;
- me->code_item = iscz_code_item;
- me->code_stop = iscz_code_stop;
+ 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"));