-/* $Id: isamb.c,v 1.31 2004-06-01 13:46:41 adam Exp $
+/* $Id: isamb.c,v 1.39 2004-06-02 18:50:37 heikki Exp $
Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004
Index Data Aps
assert(isamb->file[i].head.block_size == b_size);
b_size = b_size * 4;
}
+#if ISAMB_DEBUG
+ logf(LOG_WARN, "isamb debug enabled. Things will be slower than usual");
+#endif
return isamb;
}
xfree (isamb);
}
-
-struct ISAMB_block *open_block (ISAMB b, ISAMC_P pos)
+static struct ISAMB_block *open_block (ISAMB b, ISAMC_P pos)
{
int cat = pos&CAT_MASK;
struct ISAMB_block *p;
isamb_pp_close_x (pp, 0, 0);
}
+/* simple recursive dumper .. */
+static void isamb_dump_r (ISAMB b, ISAMB_P pos, void (*pr)(const char *str),
+ int level)
+{
+ char buf[1024];
+ char prefix_str[1024];
+ if (pos)
+ {
+ struct ISAMB_block *p = open_block (b, pos);
+ sprintf(prefix_str, "%*s %d cat=%d size=%d max=%d", level*2, "",
+ pos, p->cat, p->size, b->file[p->cat].head.block_max);
+ (*pr)(prefix_str);
+ sprintf(prefix_str, "%*s %d", level*2, "", pos);
+ if (p->leaf)
+ {
+ while (p->offset < p->size)
+ {
+ char *src = p->bytes + p->offset;
+ char *dst = buf;
+ (*b->method->code_item)(ISAMC_DECODE, p->decodeClientData,
+ &dst, &src);
+ (*b->method->log_item)(LOG_DEBUG, buf, prefix_str);
+ p->offset = src - (char*) p->bytes;
+ }
+ assert(p->offset == p->size);
+ }
+ else
+ {
+ char *src = p->bytes + p->offset;
+ int sub;
+ int item_len;
+
+ decode_ptr (&src, &sub);
+ p->offset = src - (char*) p->bytes;
+
+ isamb_dump_r(b, sub, pr, level+1);
+
+ while (p->offset < p->size)
+ {
+ decode_ptr (&src, &item_len);
+ (*b->method->log_item)(LOG_DEBUG, src, prefix_str);
+ src += item_len;
+ decode_ptr (&src, &sub);
+
+ p->offset = src - (char*) p->bytes;
+
+ isamb_dump_r(b, sub, pr, level+1);
+ }
+ }
+ close_block(b,p);
+ }
+}
+
+void isamb_dump (ISAMB b, ISAMB_P pos, void (*pr)(const char *str))
+{
+ return isamb_dump_r(b, pos, pr, 0);
+}
#if 0
/* Old isamb_pp_read that Adam wrote, kept as a reference in case we need to
(*pp->isamb->method->code_item)(ISAMC_DECODE, p->decodeClientData,
&dst, &src);
p->offset = src - (char*) p->bytes;
- key_logdump_txt(LOG_DEBUG,buf, "isamb_pp_read returning 1");
+ /* key_logdump_txt(LOG_DEBUG,buf, "isamb_pp_read returning 1"); */
return 1;
}
}
#endif
+#define NEW_FORWARD 0
+#if NEW_FORWARD
+
+#define ISAMB_DEBUG 1 /* while coding this part */
+
+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 the 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 int isamb_pp_forward_unode(ISAMB_PP pp, int pos, const void *untilbuf)
+{ /* scans a upper node until it finds a child <= untilbuf */
+ /* pp points to the key value, as always. pos is the child read from */
+ /* the buffer */
+ /* if all values are too small, returns the last child in the node */
+ /* FIXME - this can be detected, and avoided by looking at the */
+ /* parent node, but that gets messy. Presumably the cost is */
+ /* pretty low anyway */
+ struct ISAMB_block *p = pp->block[pp->level];
+ char *src=p->bytes + p->offset;
+ int item_len;
+ int cmp;
+ int nxtpos;
+ assert(!p->leaf);
+ assert(p->offset <= p->size);
+ if (p->offset == p->size)
+ return pos; /* already at the end of it */
+ while(p->offset < p->size) {
+ decode_ptr(&src,&item_len);
+ cmp=(*pp->isamb->method->compare_item)(untilbuf,src);
+ src+=item_len;
+ decode_ptr(&src,&nxtpos);
+ if (cmp<2)
+ {
+ return pos;
+ } /* found one */
+ pos=nxtpos;
+ p->offset=src-(char*)p->bytes;
+ }
+ return pos; /* that's the last one in the line */
+
+} /* forward_unode */
+
+static void isamb_pp_descend_to_leaf(ISAMB_PP pp, int pos, const void *untilbuf)
+{ /* 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_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;
+ if (untilbuf)
+ pos=isamb_pp_forward_unode(pp,pos,untilbuf);
+ isamb_pp_descend_to_leaf(pp,pos,untilbuf);
+} /* descend_to_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_leaf(pp, pos,0);
+ 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 */
+ int cmp;
+ int skips=0;
+ while (1){
+ if (!isamb_pp_read_on_leaf(pp,buf))
+ return 0;
+ /* FIXME - this is an extra function call, inline the read? */
+ cmp=(*pp->isamb->method->compare_item)(untilbuf,buf);
+ if (cmp <2){ /* found a good one */
+#if ISAMB_DEBUG
+ if (skips)
+ logf(LOG_DEBUG, "isam_pp_fwd_on_leaf skipped %d items",skips);
+#endif
+ pp->returned_numbers++;
+ return 1;
+ }
+ pp->skipped_numbers++;
+ skips++;
+ }
+} /* 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 */
+ int pos;
+ if (!isamb_pp_climb_level(pp,&pos))
+ return 0;
+ isamb_pp_descend_to_leaf(pp, pos,untilbuf);
+ return 1;
+} /* 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
+ 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:
* if cmp
* return 1
*/
- /*
- * The upper nodes consist of a sequence of nodenumbers and keys
- * When opening a block, the first node number is read in, and
- * offset points to the first key, which is the upper limit of keys
- * in the node just read.
- */
+ /*
+ * The upper nodes consist of a sequence of nodenumbers and keys
+ * When opening a block, the first node number is read in, and
+ * offset points to the first key, which is the upper limit of keys
+ * in the node just read.
+ */
char *dst = buf;
char *src;
struct ISAMB_block *p = pp->block[pp->level];
int item_len;
int pos;
int nxtpos;
+ int descending=0; /* used to prevent a border condition error */
if (!p)
return 0;
#if ISAMB_DEBUG
while (1)
{
- while ( p->offset == p->size)
+ while ( (p->offset == p->size) && !descending )
{ /* end of this block - climb higher */
+ assert (p->offset <= p->size);
#if ISAMB_DEBUG
logf(LOG_DEBUG,"isamb_pp_forward climbing from l=%d",
pp->level);
p->pos, p->offset);
#endif
assert(!p->leaf);
+ assert(p->offset <= p->size);
/* skip the child we have handled */
if (p->offset != p->size)
{
src += item_len;
decode_ptr(&src,&pos);
p->offset = src - (char*) p->bytes;
- break; /* even if this puts us at the end of the block, we need to */
- /* descend to the last pos. UGLY coding, clean up some */
- /* day */
+ break; /* even if this puts us at the end of the block, we
+ need to descend to the last pos. UGLY coding,
+ clean up some day */
}
}
if (!p->leaf)
{
src = p->bytes + p->offset;
if (p->offset == p->size)
- cmp=-2 ; /* descend to the last node, as we have no value to cmp */
+ cmp=-2 ; /* descend to the last node, as we have
+ no value to cmp */
else
{
decode_ptr(&src, &item_len);
#if ISAMB_DEBUG
- logf(LOG_DEBUG,"isamb_pp_forward (B) on a high node. ofs=%d sz=%d nxtpos=%d ",
+ logf(LOG_DEBUG,"isamb_pp_forward (B) on a high node. "
+ "ofs=%d sz=%d nxtpos=%d ",
p->offset,p->size,pos);
(*pp->isamb->method->log_item)(LOG_DEBUG, src, "");
#endif
logf(LOG_DEBUG,"isambb_pp_forward descending l=%d p=%d ",
pp->level, pos);
#endif
+ descending=1; /* prevent climbing for a while */
++(pp->level);
p = open_block(pp->isamb,pos);
pp->block[pp->level] = p ;
(pp->skipped_nodes[pp->maxlevel - pp->level -1])++;
#if ISAMB_DEBUG
logf(LOG_DEBUG,
- "isamb_pp_forward: skipping block on level %d, noting on %d (%d)",
+ "isamb_pp_forward: skipping block on level %d, noting "
+ "on %d (%d)",
pp->level, pp->maxlevel - pp->level-1 ,
pp->skipped_nodes[pp->maxlevel - pp->level-1 ]);
#endif
} /* not on a leaf */
else
{ /* on a 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 (untilbuf)
- cmp=(*pp->isamb->method->compare_item)(untilbuf,buf);
- else
- cmp=-2;
+ if (p->offset == p->size) {
+ descending = 0;
+ }
+ else
+ {
+ assert (p->offset < p->size);
+ 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 (untilbuf)
+ cmp=(*pp->isamb->method->compare_item)(untilbuf,buf);
+ else
+ cmp=-2;
#if ISAMB_DEBUG
- logf(LOG_DEBUG,"isamb_pp_forward on a leaf. cmp=%d",
- cmp);
- (*pp->isamb->method->log_item)(LOG_DEBUG, buf, "");
+ logf(LOG_DEBUG,"isamb_pp_forward on a leaf. cmp=%d",
+ cmp);
+ (*pp->isamb->method->log_item)(LOG_DEBUG, buf, "");
#endif
- if (cmp <2)
- {
-#if ISAMB_DEBUG
- if (untilbuf)
- {
- (*pp->isamb->method->log_item)(LOG_DEBUG, buf,
- "isamb_pp_forward returning 1");
- }
- else
+ if (cmp <2)
{
- (*pp->isamb->method->log_item)(LOG_DEBUG, buf,
- "isamb_pp_read returning 1 (fwd)");
- }
+#if ISAMB_DEBUG
+ if (untilbuf)
+ {
+ (*pp->isamb->method->log_item)(
+ LOG_DEBUG, buf, "isamb_pp_forward returning 1");
+ }
+ else
+ {
+ (*pp->isamb->method->log_item)(
+ LOG_DEBUG, buf, "isamb_pp_read returning 1 (fwd)");
+ }
#endif
- pp->returned_numbers++;
- return 1;
- }
- else
- pp->skipped_numbers++;
+ pp->returned_numbers++;
+ return 1;
+ }
+ else
+ pp->skipped_numbers++;
+ }
} /* leaf */
} /* main loop */
}
+#endif
int isamb_pp_num (ISAMB_PP pp)
{
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