X-Git-Url: http://git.indexdata.com/?a=blobdiff_plain;f=isamb%2Fisamb.c;h=77114239f2788119545f408d864964f48b1636be;hb=1afbdd9135e38942201f0ad0eaae5b6903755aeb;hp=bc38a557bfb0343dd921d7725da5c24c6a292558;hpb=842cbb4cd47fd56905c92429a6ede3a550b618cf;p=idzebra-moved-to-github.git

diff --git a/isamb/isamb.c b/isamb/isamb.c
index bc38a55..7711423 100644
--- a/isamb/isamb.c
+++ b/isamb/isamb.c
@@ -1,4 +1,4 @@
-/* $Id: isamb.c,v 1.28 2004-05-30 18:04:49 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
 
@@ -26,6 +26,10 @@ Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include <isamb.h>
 #include <assert.h>
 
+#ifndef ISAMB_DEBUG
+#define ISAMB_DEBUG 0
+#endif
+
 struct ISAMB_head {
     int first_block;
     int last_block;
@@ -39,6 +43,7 @@ struct ISAMB_head {
 /* maximum size of encoded buffer */
 #define DST_ITEM_MAX 256
 
+#define ISAMB_MAX_LEVEL 10
 /* approx 2*max page + max size of item */
 #define DST_BUF_SIZE 16840
 
@@ -77,6 +82,10 @@ struct ISAMB_s {
     int cache; /* 0=no cache, 1=use cache, -1=dummy isam (for testing only) */
     int log_io;        /* log level for bf_read/bf_write calls */
     int log_freelist;  /* log level for freelist handling */
+    int skipped_numbers; /* on a leaf node */
+    int returned_numbers; 
+    int skipped_nodes[ISAMB_MAX_LEVEL]; /* [0]=skipped leaves, 1=higher etc */
+    int accessed_nodes[ISAMB_MAX_LEVEL]; /* nodes we did not skip */
 };
 
 struct ISAMB_block {
@@ -97,8 +106,13 @@ struct ISAMB_PP_s {
     ISAMB isamb;
     ISAMB_P pos;
     int level;
+    int maxlevel; /* total depth */
     int total_size;
     int no_blocks;
+    int skipped_numbers; /* on a leaf node */
+    int returned_numbers; 
+    int skipped_nodes[ISAMB_MAX_LEVEL]; /* [0]=skipped leaves, 1=higher etc */
+    int accessed_nodes[ISAMB_MAX_LEVEL]; /* nodes we did not skip */
     struct ISAMB_block **block;
 };
 
@@ -160,6 +174,10 @@ ISAMB isamb_open (BFiles bfs, const char *name, int writeflag, ISAMC_M *method,
     isamb->log_io = 0;
     isamb->log_freelist = 0;
     isamb->cache = cache;
+    isamb->skipped_numbers=0;
+    isamb->returned_numbers=0;
+    for (i=0;i<ISAMB_MAX_LEVEL;i++)
+      isamb->skipped_nodes[i]= isamb->accessed_nodes[i]=0;
 
     assert (cache == 0);
     isamb->file = xmalloc (sizeof(*isamb->file) * isamb->no_cat);
@@ -190,6 +208,9 @@ ISAMB isamb_open (BFiles bfs, const char *name, int writeflag, ISAMC_M *method,
         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;
 }
 
@@ -286,6 +307,11 @@ static int get_block (ISAMB b, ISAMC_P pos, char *userbuf, int wr)
 void isamb_close (ISAMB isamb)
 {
     int i;
+    for (i=0;isamb->accessed_nodes[i];i++)
+        logf(LOG_DEBUG,"isamb_close  level leaf-%d: %d read, %d skipped",
+             i, isamb->accessed_nodes[i], isamb->skipped_nodes[i]);
+    logf(LOG_DEBUG,"isamb_close returned %d values, skipped %d",
+         isamb->skipped_numbers, isamb->returned_numbers);
     for (i = 0; i<isamb->no_cat; i++)
     {
         flush_blocks (isamb, i);
@@ -300,8 +326,7 @@ void isamb_close (ISAMB 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;
@@ -327,13 +352,14 @@ struct ISAMB_block *open_block (ISAMB b, ISAMC_P pos)
     p->size = (p->buf[1] + 256 * p->buf[2]) - ISAMB_DATA_OFFSET;
     if (p->size < 0)
     {
-        fprintf (stderr, "pos=%d\n", pos);
+        yaz_log (LOG_FATAL, "Bad block size %d in pos=%d\n", p->size, pos);
     }
     assert (p->size >= 0);
     p->offset = 0;
     p->dirty = 0;
     p->deleted = 0;
     p->decodeClientData = (*b->method->code_start)(ISAMC_DECODE);
+    yaz_log (LOG_DEBUG, "isamb_open_block: Opened block %d ofs=%d",pos, p->offset);
     return p;
 }
 
@@ -898,14 +924,20 @@ int isamb_merge (ISAMB b, ISAMC_P pos, ISAMC_I *stream)
 ISAMB_PP isamb_pp_open_x (ISAMB isamb, ISAMB_P pos, int *level)
 {
     ISAMB_PP pp = xmalloc (sizeof(*pp));
+    int i;
 
     pp->isamb = isamb;
-    pp->block = xmalloc (10 * sizeof(*pp->block));
+    pp->block = xmalloc (ISAMB_MAX_LEVEL * sizeof(*pp->block));
 
     pp->pos = pos;
     pp->level = 0;
+    pp->maxlevel=0;
     pp->total_size = 0;
     pp->no_blocks = 0;
+    pp->skipped_numbers=0;
+    pp->returned_numbers=0;
+    for (i=0;i<ISAMB_MAX_LEVEL;i++)
+        pp->skipped_nodes[i] = pp->accessed_nodes[i]=0;
     while (1)
     {
         struct ISAMB_block *p = open_block (isamb, pos);
@@ -914,15 +946,17 @@ ISAMB_PP isamb_pp_open_x (ISAMB isamb, ISAMB_P pos, int *level)
 
         pp->total_size += p->size;
         pp->no_blocks++;
-
         if (p->leaf)
             break;
 
+                                        
         decode_ptr (&src, &pos);
         p->offset = src - p->bytes;
         pp->level++;
+        pp->accessed_nodes[pp->level]++; 
     }
     pp->block[pp->level+1] = 0;
+    pp->maxlevel=pp->level;
     if (level)
         *level = pp->level;
     return pp;
@@ -938,6 +972,19 @@ void isamb_pp_close_x (ISAMB_PP pp, int *size, int *blocks)
     int i;
     if (!pp)
         return;
+    logf(LOG_DEBUG,"isamb_pp_close lev=%d returned %d values, skipped %d",
+        pp->maxlevel, pp->skipped_numbers, pp->returned_numbers);
+    for (i=pp->maxlevel;i>=0;i--)
+        if ( pp->skipped_nodes[i] || pp->accessed_nodes[i])
+            logf(LOG_DEBUG,"isamb_pp_close  level leaf-%d: %d read, %d skipped", i,
+                 pp->accessed_nodes[i], pp->skipped_nodes[i]);
+    pp->isamb->skipped_numbers += pp->skipped_numbers;
+    pp->isamb->returned_numbers += pp->returned_numbers;
+    for (i=pp->maxlevel;i>=0;i--)
+    {
+        pp->isamb->accessed_nodes[i] += pp->accessed_nodes[i];
+        pp->isamb->skipped_nodes[i] += pp->skipped_nodes[i];
+    }
     if (size)
         *size = pp->total_size;
     if (blocks)
@@ -960,6 +1007,69 @@ void isamb_pp_close (ISAMB_PP pp)
     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
+   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;
@@ -979,7 +1089,7 @@ int isamb_pp_read (ISAMB_PP pp, void *buf)
             pp->block[pp->level] = 0;
             (pp->level)--;
             p = pp->block[pp->level];
-            assert (!p->leaf);  /* must be int */
+            assert (!p->leaf);  
         }
         src = p->bytes + p->offset;
         
@@ -998,7 +1108,7 @@ int isamb_pp_read (ISAMB_PP pp, void *buf)
             pp->total_size += p->size;
             pp->no_blocks++;
             
-            if (p->leaf) /* leaf */
+            if (p->leaf) 
             {
                 break;
             }
@@ -1014,8 +1124,405 @@ int isamb_pp_read (ISAMB_PP pp, void *buf)
     (*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"); */
+    return 1;
+}
+
+#else
+int isamb_pp_read (ISAMB_PP pp, void *buf)
+{
+    return isamb_pp_forward(pp,buf,0);
+}
+#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:
+     *   while 1
+     *     while at end of node
+     *       climb higher. If out, return 0
+     *     while not on a leaf (and not at its end)
+     *       decode next
+     *       if cmp
+     *         descend to node
+     *     decode next
+     *     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.
+      */
+    char *dst = buf;
+    char *src;
+    struct ISAMB_block *p = pp->block[pp->level];
+    int cmp;
+    int item_len;
+    int pos;
+    int nxtpos;
+    int descending=0; /* used to prevent a border condition error */
+    if (!p)
+        return 0;
+#if ISAMB_DEBUG
+    logf(LOG_DEBUG,"isamb_pp_forward starting [%p] p=%d",pp,p->pos);
+    
+    (*pp->isamb->method->log_item)(LOG_DEBUG, untilbuf, "until");
+    (*pp->isamb->method->log_item)(LOG_DEBUG, buf, "buf");
+#endif
+
+    while (1)
+    {
+        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);
+#endif
+            if (pp->level == 0)
+            {
+#if ISAMB_DEBUG
+                logf(LOG_DEBUG,"isamb_pp_forward returning 0 at root");
+#endif
+                return 0; /* at end of the root, nothing left */
+            }
+            close_block(pp->isamb, pp->block[pp->level]);
+            pp->block[pp->level]=0;
+            (pp->level)--;
+            p=pp->block[pp->level];
+#if ISAMB_DEBUG
+            logf(LOG_DEBUG,"isamb_pp_forward climbed to node %d off=%d",
+                            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 = p->bytes + p->offset;
+                decode_ptr(&src, &item_len);
+#if ISAMB_DEBUG		
+		(*pp->isamb->method->log_item)(LOG_DEBUG, src,
+					       " isamb_pp_forward "
+					       "climb skipping old key");
+#endif
+                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 */
+            }
+        }
+        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 */
+            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 ",
+                        p->offset,p->size,pos);
+		(*pp->isamb->method->log_item)(LOG_DEBUG, src, "");
+#endif
+                if (untilbuf)
+                    cmp=(*pp->isamb->method->compare_item)(untilbuf,src);
+                else
+                    cmp=-2;
+                src += item_len;
+                decode_ptr(&src,&nxtpos);
+            }
+            if (cmp<2)
+            { 
+#if ISAMB_DEBUG
+                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->total_size += p->size;
+                (pp->accessed_nodes[pp->maxlevel - pp->level])++;
+                pp->no_blocks++;
+                if ( !p->leaf)
+                { /* block starts with a pos */
+                    src = p->bytes + p->offset;
+                    decode_ptr(&src,&pos);
+                    p->offset=src-(char*) p->bytes;
+#if ISAMB_DEBUG
+                    logf(LOG_DEBUG,"isamb_pp_forward: block %d starts with %d",
+                                    p->pos, pos);
+#endif
+                } 
+            } /* descend to the node */
+            else
+            { /* skip the node */
+                p->offset = src - (char*) p->bytes;
+                pos=nxtpos;
+                (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)",
+                    pp->level, pp->maxlevel - pp->level-1 , 
+                    pp->skipped_nodes[pp->maxlevel - pp->level-1 ]);
+#endif
+                /* 0 is always leafs, 1 is one level above leafs etc, no
+                 * matter how high tree */
+            }
+        } /* not on a leaf */
+        else
+        { /* on a leaf */
+	    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, "");
+#endif
+		if (cmp <2)
+		{
+#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++;
+	    }
+        } /* leaf */
+    } /* main loop */
+}
+
+#endif
 
 int isamb_pp_num (ISAMB_PP pp)
 {