+int key_get_pos (const void *p)
+{
+ struct it_key key;
+ memcpy (&key, p, sizeof(key));
+ return key.seqno;
+}
+
+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)