-/* $Id: isamb.c,v 1.38 2004-06-02 17:26:03 heikki Exp $
+/* $Id: isamb.c,v 1.41 2004-06-03 00:23:48 adam Exp $
Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004
Index Data Aps
int deleted;
int offset;
char *bytes;
+ char *cbuf;
unsigned char *buf;
void *decodeClientData;
int log_rw;
p->pos = pos;
p->cat = pos & CAT_MASK;
p->buf = xmalloc (b->file[cat].head.block_size);
+ p->cbuf = 0;
if (!get_block (b, pos, p->buf, 0))
{
debug the more complex pp_read that also forwards. May be deleted near end
of 2004, if it has not shown to be useful */
+
int isamb_pp_read (ISAMB_PP pp, void *buf)
{
char *dst = buf;
#endif
#define NEW_FORWARD 0
-#if NEW_FORWARD
+#if NEW_FORWARD == 1
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*/
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) */
+ /* returns the node to (consider to) descend to in *pos) */
struct ISAMB_block *p = pp->block[pp->level];
char *src;
int item_len;
} /* climb_level */
-static void isamb_pp_descend_to_first_leaf(ISAMB_PP pp, int pos)
+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;
++(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);
+ 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;
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 */
+ 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_first_leaf(pp, pos);
+ 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 */
- assert (!"FIXME - not done yet");
- return 0;
+ 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 */
- assert (!"FIXME - not done yet");
- return 0;
+ 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)
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;
}
} /* isam_pp_forward (new version) */
-#else
+#elif NEW_FORWARD == 0
int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilbuf)
{
} /* main loop */
}
+#elif NEW_FORWARD == 2
+
+int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilb)
+{
+ char *dst = buf;
+ char *src;
+ struct ISAMB_block *p = pp->block[pp->level];
+ if (!p)
+ return 0;
+
+again:
+ while (p->offset == p->size)
+ {
+ int pos, item_len;
+ while (p->offset == p->size)
+ {
+ if (pp->level == 0)
+ return 0;
+ close_block (pp->isamb, pp->block[pp->level]);
+ pp->block[pp->level] = 0;
+ (pp->level)--;
+ p = pp->block[pp->level];
+ assert (!p->leaf);
+ }
+
+ assert(!p->leaf);
+ src = p->bytes + p->offset;
+
+ decode_ptr (&src, &item_len);
+ src += item_len;
+ decode_ptr (&src, &pos);
+
+ p->offset = src - (char*) p->bytes;
+
+ src = p->bytes + p->offset;
+
+ while(1)
+ {
+ if (!untilb || p->offset == p->size)
+ break;
+ assert(p->offset < p->size);
+ decode_ptr (&src, &item_len);
+ if ((*pp->isamb->method->compare_item)(untilb, src) <= 1)
+ break;
+ src += item_len;
+ decode_ptr (&src, &pos);
+ p->offset = src - (char*) p->bytes;
+ }
+
+ pp->level++;
+
+ while (1)
+ {
+ pp->block[pp->level] = p = open_block (pp->isamb, pos);
+
+ pp->total_size += p->size;
+ pp->no_blocks++;
+
+ if (p->leaf)
+ {
+ break;
+ }
+
+ src = p->bytes + p->offset;
+ while(1)
+ {
+ decode_ptr (&src, &pos);
+ p->offset = src - (char*) p->bytes;
+
+ if (!untilb || p->offset == p->size)
+ break;
+ assert(p->offset < p->size);
+ decode_ptr (&src, &item_len);
+ if ((*pp->isamb->method->compare_item)(untilb, src) <= 1)
+ break;
+ src += item_len;
+ }
+ pp->level++;
+ }
+ }
+ assert (p->offset < p->size);
+ assert (p->leaf);
+ while(1)
+ {
+ char *dst0 = dst;
+ src = p->bytes + p->offset;
+ (*pp->isamb->method->code_item)(ISAMC_DECODE, p->decodeClientData,
+ &dst, &src);
+ p->offset = src - (char*) p->bytes;
+ if (!untilb || (*pp->isamb->method->compare_item)(untilb, dst0) <= 1)
+ break;
+ dst = dst0;
+ if (p->offset == p->size) goto again;
+ }
+ /* key_logdump_txt(LOG_DEBUG,buf, "isamb_pp_read returning 1"); */
+ return 1;
+}
+
#endif
int isamb_pp_num (ISAMB_PP pp)
projects / idzebra-moved-to-github.git / blobdiff