-/* $Id: isamb.c,v 1.37 2004-06-02 14:07:01 heikki Exp $
+/* $Id: isamb.c,v 1.38 2004-06-02 17:26:03 heikki Exp $
Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004
Index Data Aps
}
#endif
+#define NEW_FORWARD 0
+#if NEW_FORWARD
+
+
+static int isamb_pp_read_on_leaf(ISAMB_PP pp, void *buf)
+{ /* reads the next item on the current leaf, returns 0 if end of leaf*/
+ struct ISAMB_block *p = pp->block[pp->level];
+ char *dst;
+ char *src;
+ if (p->offset == p->size) {
+#if ISAMB_DEBUG
+ logf(LOG_DEBUG,"isamb_pp_read_on_leaf returning 0 on node %d",p->pos);
+#endif
+ return 0; /* at end of leaf */
+ }
+ src=p->bytes + p->offset;
+ dst=buf;
+ (*pp->isamb->method->code_item)
+ (ISAMC_DECODE, p->decodeClientData,&dst, &src);
+ p->offset = src - (char*) p->bytes;
+#if ISAMB_DEBUG
+ (*pp->isamb->method->log_item)(LOG_DEBUG, buf, "read_on_leaf returning 1");
+#endif
+ return 1;
+} /* read_on_leaf */
+
+
+static int isamb_pp_climb_level(ISAMB_PP pp, int *pos)
+{ /* climbs higher in the tree, until finds a level with data left */
+ /* returns teh node to (consider to) descend to in *pos) */
+ struct ISAMB_block *p = pp->block[pp->level];
+ char *src;
+ int item_len;
+ assert(p->offset <= p->size);
+ if (pp->level==0)
+ {
+#if ISAMB_DEBUG
+ logf(LOG_DEBUG,"isamb_pp_climb_level returning 0 at root");
+ return 0;
+#endif
+ }
+ close_block(pp->isamb, pp->block[pp->level]);
+ pp->block[pp->level]=0;
+ (pp->level)--;
+ p=pp->block[pp->level];
+ logf(LOG_DEBUG,"isamb_pp_climb_level climbed to node %d ofs=%d",
+ p->pos, p->offset);
+ assert (!p->leaf);
+ assert (p->offset <= p->size);
+ if (p->offset == p->size ) {
+ /* we came from the last pointer, climb on */
+ if (!isamb_pp_climb_level(pp,pos))
+ return 0;
+ p=pp->block[pp->level];
+ }
+ /* skip the child we just came from */
+ assert (p->offset < p->size );
+ src=p->bytes + p->offset;
+ decode_ptr(&src, &item_len);
+ src += item_len;
+ decode_ptr(&src, pos);
+ p->offset=src - (char *)p->bytes;
+ return 1;
+} /* climb_level */
+
+
+static void isamb_pp_descend_to_first_leaf(ISAMB_PP pp, int pos)
+{ /* climbs down the tree, from pos, to the leftmost leaf */
+ struct ISAMB_block *p = pp->block[pp->level];
+ char *src;
+ assert(!p->leaf);
+ ++(pp->level);
+ p=open_block(pp->isamb, pos);
+ pp->block[pp->level]=p;
+ ++(pp->accessed_nodes[pp->maxlevel-pp->level]);
+ ++(pp->no_blocks);
+#if ISAMB_DEBUG
+ logf(LOG_DEBUG,"isamb_pp_descend_to_first_leaf "
+ "got lev %d node %d lf=%d",
+ pp->level, p->pos, p->leaf);
+#endif
+ if (p->leaf)
+ return;
+ assert (p->offset==0 );
+ src=p->bytes + p->offset;
+ decode_ptr(&src, &pos);
+ p->offset=src-(char*)p->bytes;
+ isamb_pp_descend_to_first_leaf(pp,pos);
+} /* descend_to_first_leaf */
+
+static int isamb_pp_find_next_leaf(ISAMB_PP pp)
+{ /* finds the next leaf by climbing up and down */
+ int pos;
+ if (!isamb_pp_climb_level(pp,&pos))
+ return 0;
+ isamb_pp_descend_to_first_leaf(pp, pos);
+ return 1;
+}
+static int isamb_pp_forward_on_leaf(ISAMB_PP pp, void *buf, const void *untilbuf)
+{ /* forwards on the current leaf, returns 0 if not found */
+ assert (!"FIXME - not done yet");
+ return 0;
+} /* forward_on_leaf */
+
+static int isamb_pp_climb_desc(ISAMB_PP pp, void *buf, const void *untilbuf)
+{ /* climbs up and descends to a leaf where values >= *untilbuf are found */
+ assert (!"FIXME - not done yet");
+ return 0;
+} /* climb_desc */
+
+int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilbuf)
+{
+#if ISAMB_DEBUG
+ struct ISAMB_block *p = pp->block[pp->level];
+ assert(p->leaf);
+#endif
+ untilbuf=0; /*FIXME - disabling the forward part */
+ if (untilbuf) {
+ if (isamb_pp_forward_on_leaf( pp, buf, untilbuf))
+ return 1;
+ if (! isamb_pp_climb_desc( pp, buf, untilbuf))
+ return 0; /* could not find a leaf */
+ do{
+ if (isamb_pp_forward_on_leaf( pp, buf, untilbuf))
+ return 1;
+ }while ( isamb_pp_find_next_leaf(pp));
+ return 0; /* could not find at all */
+ }
+ else { /* no untilbuf, a straight read */
+ /* FIXME - this should be moved
+ * directly into the pp_read */
+ /* keeping here now, to keep same
+ * interface as the old fwd */
+ if (isamb_pp_read_on_leaf( pp, buf))
+ return 1;
+ if (isamb_pp_find_next_leaf(pp))
+ return isamb_pp_read_on_leaf(pp, buf);
+ else
+ return 0;
+ }
+} /* isam_pp_forward (new version) */
+
+#else
+
int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilbuf)
{
/* pseudocode:
} /* main loop */
}
+#endif
int isamb_pp_num (ISAMB_PP pp)
{