From 253865441b1bbd65360092eaf281939be82798db Mon Sep 17 00:00:00 2001
From: leitner <leitner>
Date: Fri, 1 Apr 2005 20:35:22 +0000
Subject: [PATCH] change type 1 indices to be two tables of uint32 instead of
 one table of tuples this ought to be more cache friendly

---
 addindex.c | 19 ++++++++++++-------
 tinyldap.c | 41 ++++++++++-------------------------------
 2 files changed, 22 insertions(+), 38 deletions(-)

diff --git a/addindex.c b/addindex.c
index bef278f..8908f83 100644
--- a/addindex.c
+++ b/addindex.c
@@ -149,18 +149,23 @@ int main(int argc,char* argv[]) {
       }
       uint32_pack(map+casesensitive,ignorecase);
       uint32_pack(map+filelen,fastindex);
-      uint32_pack(map+filelen+4,filelen+(counted+3)*4*(fastindex+1));
+      uint32_pack(map+filelen+4,filelen+3*4+(counted)*4*(fastindex+1));
       uint32_pack(map+filelen+8,wanted);
       {
 	char* x=map+filelen+12;
 	unsigned long i;
 	for (i=0; i<counted; ++i) {
-	  if (fastindex) {
-	    uint32_pack(x,((uint32*)idx.root)[i*2]);
-	    uint32_pack(x+4,((uint32*)idx.root)[i*2+1]);
-	    x+=8;
-	  } else {
-	    uint32_pack(x,((uint32*)idx.root)[i]);
+	  uint32_pack(x,((uint32*)idx.root)[i<<fastindex]);
+	  x+=4;
+	}
+	if (fastindex) {
+	  /* index type 1 also saves the record number for each table
+	   * entry.  Since normal searches will bsearch over the offsets
+	   * and only then ask for the record number, we try to be cache
+	   * friendly and save one table with the offsets and one table
+	   * with the record numbers, instead of one table with tuples. */
+	  for (i=0; i<counted; ++i) {
+	    uint32_pack(x,((uint32*)idx.root)[i*2+1]);
 	    x+=4;
 	  }
 	}
diff --git a/tinyldap.c b/tinyldap.c
index 73a1aff..1ce574b 100644
--- a/tinyldap.c
+++ b/tinyldap.c
@@ -224,44 +224,26 @@ static int indexable(struct Filter* f) {
  * table to find the record with the attribute.  This does not work for
  * objectClass, because the classes are stored in a different string
  * table to remove duplicates. */
+
+/* this kludge is only necessary for index type 0.  Index type 1 also
+ * saves the record number. */
 /* find record given a data pointer */
 static long findrec(uint32 dat) {
   uint32* records=(uint32*)(map+indices_offset);
   uint32 bottom=0;
   uint32 top=record_count-1;
-#ifdef DEBUG
-  buffer_puts(buffer_2,"findrec(");
-  buffer_putulong(buffer_2,dat);
-  buffer_putsflush(buffer_2,")... ");
-#endif
+
   while ((top>=bottom)) {
     uint32 mid=(top+bottom)/2;
     uint32 l;
 
     l=uint32_read(map+uint32_read((char*)(&records[mid]))+8);
-#if 0
-    buffer_puts(buffer_2,"findrec match[");
-    buffer_putulong(buffer_2,bottom);
-    buffer_puts(buffer_2,"..");
-    buffer_putulong(buffer_2,top);
-    buffer_puts(buffer_2,"]: ");
-    buffer_putulong(buffer_2,l);
-    buffer_puts(buffer_2," <-> ");
-    buffer_putulong(buffer_2,dat);
-    buffer_putsflush(buffer_2,": ");
-#endif
     if (l<=dat) {
       if (mid>=record_count-1)
 	l=uint32_read(map+uint32_read((char*)(&records[0]))+12);
       else
 	l=uint32_read(map+uint32_read((char*)(&records[mid+1]))+8);
       if (l>dat) {
-#if 0
-	buffer_putsflush(buffer_2,"found!\n");
-#endif
-#ifdef DEBUG
-	buffer_putsflush(buffer_2,"done!\n");
-#endif
 	return mid;	/* found! */
       }
       bottom=mid+1;
@@ -270,9 +252,6 @@ static long findrec(uint32 dat) {
 	top=mid-1;
       else
 	break;
-#if 0
-    buffer_putsflush(buffer_2,"nope :-(\n");
-#endif
   }
   buffer_putsflush(buffer_2,"findrec failed!\n");
   return -1;
@@ -314,7 +293,7 @@ static void tagmatches(uint32* index,unsigned int elements,struct string* s,
     uint32 k;
     int l;
 
-    k=uint32_read((char*)(&index[mid<<index_type]));
+    k=uint32_read((char*)(&index[mid]));
 #ifdef DEBUG
     buffer_puts(buffer_2,"match[");
     buffer_putulong(buffer_2,bottom);
@@ -336,7 +315,7 @@ static void tagmatches(uint32* index,unsigned int elements,struct string* s,
       if (index_type==0)
 	rec=findrec(k);
       else if (index_type==1)
-	rec=uint32_read((char*)(&index[(mid<<index_type)+1]));
+	rec=uint32_read((char*)(&index[mid+elements]));
       else {
 	buffer_puts(buffer_2,"unsupported index type ");
 	buffer_putulong(buffer_2,index_type);
@@ -348,23 +327,23 @@ static void tagmatches(uint32* index,unsigned int elements,struct string* s,
       /* there may be multiple matches.
 	* Look before and after mid, too */
       for (k=mid-1; k>0; --k) {
-	m=uint32_read((char*)(&index[k<<index_type]));
+	m=uint32_read((char*)(&index[k]));
 	if ((l=match(s,map+m))==0) {
 	  if (index_type==0)
 	    rec=findrec(m);
 	  else if (index_type==1)
-	    rec=uint32_read((char*)(&index[(k<<index_type)+1]));
+	    rec=uint32_read((char*)(&index[k+elements]));
 	  if (rec>=0)
 	    setbit(bitfield,rec);
 	} else break;
       }
       for (k=mid+1; k<elements; ++k) {
-	m=uint32_read((char*)(&index[k<<index_type]));
+	m=uint32_read((char*)(&index[k]));
 	if ((l=match(s,map+m))==0) {
 	  if (index_type==0)
 	    rec=findrec(m);
 	  else if (index_type==1)
-	    rec=uint32_read((char*)(&index[(k<<index_type)+1]));
+	    rec=uint32_read((char*)(&index[k+elements]));
 	  if (rec>=0)
 	    setbit(bitfield,rec);
 	} else break;