From 8fa10ae668b2fd1e35b7b5b36a1a0b42bd5698e2 Mon Sep 17 00:00:00 2001 From: Hallvard Furuseth Date: Tue, 13 Sep 2011 09:39:28 +0200 Subject: [PATCH] libmdb IDL cleanup. Microoptimize IDL search. Use RANGE_ when IDL is known to be a range. --- libraries/libmdb/midl.c | 40 +++++++++++++++++++--------------------- 1 file changed, 19 insertions(+), 21 deletions(-) diff --git a/libraries/libmdb/midl.c b/libraries/libmdb/midl.c index 2f882ad..30f7410 100644 --- a/libraries/libmdb/midl.c +++ b/libraries/libmdb/midl.c @@ -39,32 +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 ) @@ -73,11 +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; } @@ -235,32 +234,31 @@ 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 )