]> git.sur5r.net Git - openldap/blobdiff - libraries/libmdb/midl.c
Fix libmdb comments
[openldap] / libraries / libmdb / midl.c
index 0af517dbb531c72e798840b50ad44f826a4c70c2..a2cb86165961ca4dc92b7336f1d5cc90c6a0260a 100644 (file)
@@ -3,7 +3,7 @@
 /* $OpenLDAP$ */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 2000-2011 The OpenLDAP Foundation.
+ * Copyright 2000-2012 The OpenLDAP Foundation.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -15,7 +15,9 @@
  * <http://www.OpenLDAP.org/license.html>.
  */
 
+#include <limits.h>
 #include <string.h>
+#include <stdlib.h>
 #include <sys/types.h>
 #include <assert.h>
 #include "midl.h"
@@ -28,6 +30,7 @@
  */
 #define CMP(x,y)        ( (x) < (y) ? -1 : (x) > (y) )
 
+#if 0  /* superseded by append/sort */
 static unsigned mdb_midl_search( IDL ids, ID id )
 {
        /*
@@ -36,32 +39,31 @@ static unsigned mdb_midl_search( IDL ids, ID id )
         * if not found, returns first position greater than id
         */
        unsigned base = 0;
-       unsigned cursor = 0;
+       unsigned cursor = 1;
        int val = 0;
        unsigned n = ids[0];
 
        while( 0 < n ) {
-               int pivot = n >> 1;
-               cursor = base + pivot;
-               val = CMP( ids[cursor + 1], id );
+               unsigned pivot = n >> 1;
+               cursor = base + pivot + 1;
+               val = CMP( ids[cursor], id );
 
                if( val < 0 ) {
                        n = pivot;
 
                } else if ( val > 0 ) {
-                       base = cursor + 1;
+                       base = cursor;
                        n -= pivot + 1;
 
                } else {
-                       return cursor + 1;
+                       return cursor;
                }
        }
        
        if( val > 0 ) {
-               return cursor + 2;
-       } else {
-               return cursor + 1;
+               ++cursor;
        }
+       return cursor;
 }
 
 int mdb_midl_insert( IDL ids, ID id )
@@ -70,11 +72,11 @@ int mdb_midl_insert( IDL ids, ID id )
 
        if (MDB_IDL_IS_RANGE( ids )) {
                /* if already in range, treat as a dup */
-               if (id >= MDB_IDL_FIRST(ids) && id <= MDB_IDL_LAST(ids))
+               if (id >= MDB_IDL_RANGE_FIRST(ids) && id <= MDB_IDL_RANGE_LAST(ids))
                        return -1;
-               if (id < MDB_IDL_FIRST(ids))
+               if (id < MDB_IDL_RANGE_FIRST(ids))
                        ids[1] = id;
-               else if (id > MDB_IDL_LAST(ids))
+               else if (id > MDB_IDL_RANGE_LAST(ids))
                        ids[2] = id;
                return 0;
        }
@@ -89,6 +91,7 @@ int mdb_midl_insert( IDL ids, ID id )
 
        if ( x <= ids[0] && ids[x] == id ) {
                /* duplicate */
+               assert(0);
                return -1;
        }
 
@@ -112,6 +115,135 @@ int mdb_midl_insert( IDL ids, ID id )
 
        return 0;
 }
+#endif
+
+IDL mdb_midl_alloc()
+{
+       IDL ids = malloc((MDB_IDL_UM_MAX+1) * sizeof(ID));
+       *ids++ = MDB_IDL_UM_MAX;
+       return ids;
+}
+
+void mdb_midl_free(IDL ids)
+{
+       free(ids-1);
+}
+
+int mdb_midl_shrink( IDL *idp )
+{
+       IDL ids = *idp;
+       if (ids[-1] > MDB_IDL_UM_MAX) {
+               ids = realloc(ids, (MDB_IDL_UM_MAX+1) * sizeof(ID));
+               *ids++ = MDB_IDL_UM_MAX;
+               *idp = ids;
+               return 1;
+       }
+       return 0;
+}
+
+int mdb_midl_append( IDL *idp, ID id )
+{
+       IDL ids = *idp;
+       /* Too big? */
+       if (ids[0] >= ids[-1]) {
+               IDL idn = ids-1;
+               /* grow it */
+               idn = realloc(idn, (*idn + MDB_IDL_UM_MAX + 1) * sizeof(ID));
+               if (!idn)
+                       return -1;
+               *idn++ += MDB_IDL_UM_MAX;
+               ids = idn;
+               *idp = ids;
+       }
+       ids[0]++;
+       ids[ids[0]] = id;
+       return 0;
+}
+
+int mdb_midl_append_list( IDL *idp, IDL app )
+{
+       IDL ids = *idp;
+       /* Too big? */
+       if (ids[0] + app[0] >= ids[-1]) {
+               IDL idn = ids-1;
+               /* grow it */
+               idn = realloc(idn, (*idn + app[-1]) * sizeof(ID));
+               if (!idn)
+                       return -1;
+               *idn++ += app[-1];
+               ids = idn;
+               *idp = ids;
+       }
+       memcpy(&ids[ids[0]+1], &app[1], app[0] * sizeof(ID));
+       ids[0] += app[0];
+       return 0;
+}
+
+/* Quicksort + Insertion sort for small arrays */
+
+#define SMALL  8
+#define        SWAP(a,b)       { itmp=(a); (a)=(b); (b)=itmp; }
+
+void
+mdb_midl_sort( IDL ids )
+{
+       /* Max possible depth of int-indexed tree * 2 items/level */
+       int istack[sizeof(int)*CHAR_BIT * 2];
+       int i,j,k,l,ir,jstack;
+       ID a, itmp;
+
+       ir = ids[0];
+       l = 1;
+       jstack = 0;
+       for(;;) {
+               if (ir - l < SMALL) {   /* Insertion sort */
+                       for (j=l+1;j<=ir;j++) {
+                               a = ids[j];
+                               for (i=j-1;i>=1;i--) {
+                                       if (ids[i] >= a) break;
+                                       ids[i+1] = ids[i];
+                               }
+                               ids[i+1] = a;
+                       }
+                       if (jstack == 0) break;
+                       ir = istack[jstack--];
+                       l = istack[jstack--];
+               } else {
+                       k = (l + ir) >> 1;      /* Choose median of left, center, right */
+                       SWAP(ids[k], ids[l+1]);
+                       if (ids[l] < ids[ir]) {
+                               SWAP(ids[l], ids[ir]);
+                       }
+                       if (ids[l+1] < ids[ir]) {
+                               SWAP(ids[l+1], ids[ir]);
+                       }
+                       if (ids[l] < ids[l+1]) {
+                               SWAP(ids[l], ids[l+1]);
+                       }
+                       i = l+1;
+                       j = ir;
+                       a = ids[l+1];
+                       for(;;) {
+                               do i++; while(ids[i] > a);
+                               do j--; while(ids[j] < a);
+                               if (j < i) break;
+                               SWAP(ids[i],ids[j]);
+                       }
+                       ids[l+1] = ids[j];
+                       ids[j] = a;
+                       jstack += 2;
+                       if (ir-i+1 >= j-1) {
+                               istack[jstack] = ir;
+                               istack[jstack-1] = i;
+                               ir = j-1;
+                       } else {
+                               istack[jstack] = j-1;
+                               istack[jstack-1] = l;
+                               l = i;
+                       }
+               }
+       }
+}
 
 unsigned mdb_mid2l_search( ID2L ids, ID id )
 {
@@ -121,32 +253,31 @@ unsigned mdb_mid2l_search( ID2L ids, ID id )
         * if not found, returns first position greater than id
         */
        unsigned base = 0;
-       unsigned cursor = 0;
+       unsigned cursor = 1;
        int val = 0;
        unsigned n = ids[0].mid;
 
        while( 0 < n ) {
-               int pivot = n >> 1;
-               cursor = base + pivot;
-               val = CMP( id, ids[cursor + 1].mid );
+               unsigned pivot = n >> 1;
+               cursor = base + pivot + 1;
+               val = CMP( id, ids[cursor].mid );
 
                if( val < 0 ) {
                        n = pivot;
 
                } else if ( val > 0 ) {
-                       base = cursor + 1;
+                       base = cursor;
                        n -= pivot + 1;
 
                } else {
-                       return cursor + 1;
+                       return cursor;
                }
        }
 
        if( val > 0 ) {
-               return cursor + 2;
-       } else {
-               return cursor + 1;
+               ++cursor;
        }
+       return cursor;
 }
 
 int mdb_mid2l_insert( ID2L ids, ID2 *id )
@@ -166,7 +297,7 @@ int mdb_mid2l_insert( ID2L ids, ID2 *id )
                return -1;
        }
 
-       if ( ids[0].mid >= MDB_IDL_DB_MAX ) {
+       if ( ids[0].mid >= MDB_IDL_UM_MAX ) {
                /* too big */
                return -2;