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96 lines
1.6 KiB
C
96 lines
1.6 KiB
C
/* Lifted from OpenLDAP back-bdb/idl.c */
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#include <strings.h>
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#include <sys/types.h>
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#include <assert.h>
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#include "idl.h"
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typedef unsigned long pgno_t;
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/* Sort the IDLs from highest to lowest */
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#define IDL_CMP(x,y) ( x > y ? -1 : ( x < y ? 1 : 0 ) )
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unsigned mdb_idl_search( ID *ids, ID id )
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{
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/*
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* binary search of id in ids
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* if found, returns position of id
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* if not found, returns first position greater than id
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*/
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unsigned base = 0;
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unsigned cursor = 0;
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int val = 0;
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unsigned n = ids[0];
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while( 0 < n ) {
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int pivot = n >> 1;
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cursor = base + pivot;
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val = IDL_CMP( id, ids[cursor + 1] );
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if( val < 0 ) {
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n = pivot;
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} else if ( val > 0 ) {
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base = cursor + 1;
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n -= pivot + 1;
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} else {
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return cursor + 1;
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}
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}
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if( val > 0 ) {
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return cursor + 2;
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} else {
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return cursor + 1;
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}
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}
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int mdb_idl_insert( ID *ids, ID id )
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{
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unsigned x;
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if (MDB_IDL_IS_RANGE( ids )) {
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/* if already in range, treat as a dup */
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if (id >= MDB_IDL_FIRST(ids) && id <= MDB_IDL_LAST(ids))
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return -1;
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if (id < MDB_IDL_FIRST(ids))
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ids[1] = id;
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else if (id > MDB_IDL_LAST(ids))
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ids[2] = id;
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return 0;
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}
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x = mdb_idl_search( ids, id );
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assert( x > 0 );
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if( x < 1 ) {
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/* internal error */
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return -2;
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}
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if ( x <= ids[0] && ids[x] == id ) {
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/* duplicate */
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return -1;
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}
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if ( ++ids[0] >= MDB_IDL_DB_MAX ) {
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if( id < ids[1] ) {
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ids[1] = id;
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ids[2] = ids[ids[0]-1];
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} else if ( ids[ids[0]-1] < id ) {
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ids[2] = id;
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} else {
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ids[2] = ids[ids[0]-1];
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}
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ids[0] = NOID;
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} else {
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/* insert id */
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AC_MEMCPY( &ids[x+1], &ids[x], (ids[0]-x) * sizeof(ID) );
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ids[x] = id;
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}
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return 0;
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}
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