X-Git-Url: http://git.indexdata.com/?a=blobdiff_plain;f=isamb%2Fisamb.c;h=70fcccd551e7f9acccaffc67383bcee5688071dd;hb=461f576fcd1ea465a917d34cecf01a7c9ca9c463;hp=af0a705b22b5712f1ae250437543ab1cbf1d0ace;hpb=1b55efb5218c3a0d60265168a572240ce2c85b03;p=idzebra-moved-to-github.git

diff --git a/isamb/isamb.c b/isamb/isamb.c
index af0a705..70fcccd 100644
--- a/isamb/isamb.c
+++ b/isamb/isamb.c
@@ -1,4 +1,4 @@
-/* $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
 
@@ -97,6 +97,7 @@ struct ISAMB_block {
     int deleted;
     int offset;
     char *bytes;
+    char *cbuf;
     unsigned char *buf;
     void *decodeClientData;
     int log_rw;
@@ -336,6 +337,7 @@ static struct ISAMB_block *open_block (ISAMB b, ISAMC_P pos)
     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))
     {
@@ -1070,6 +1072,7 @@ void isamb_dump (ISAMB b, ISAMB_P pos, void (*pr)(const char *str))
    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;
@@ -1136,8 +1139,8 @@ int isamb_pp_read (ISAMB_PP pp, void *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*/
@@ -1164,7 +1167,7 @@ static int isamb_pp_read_on_leaf(ISAMB_PP pp, void *buf)
 
 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;
@@ -1201,7 +1204,40 @@ static int isamb_pp_climb_level(ISAMB_PP pp, int *pos)
 } /* 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;
@@ -1212,9 +1248,9 @@ static void isamb_pp_descend_to_first_leaf(ISAMB_PP pp, int pos)
     ++(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;
@@ -1222,27 +1258,48 @@ static void isamb_pp_descend_to_first_leaf(ISAMB_PP pp, int pos)
     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)
@@ -1251,7 +1308,6 @@ 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;
@@ -1277,7 +1333,7 @@ int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilbuf)
     }
 } /* isam_pp_forward (new version) */
 
-#else
+#elif NEW_FORWARD == 0
 
 int isamb_pp_forward (ISAMB_PP pp, void *buf, const void *untilbuf)
 {
@@ -1468,6 +1524,104 @@ 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)