/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 2006
 *      Sleepycat Software.  All rights reserved.
 *
 * $Id: VerifyUtils.java,v 1.1 2006/05/06 09:01:56 ckaestne Exp $
 */

package com.sleepycat.je.cleaner; 

import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

import com.sleepycat.je.Database;
import com.sleepycat.je.DatabaseException;
import com.sleepycat.je.DbInternal;
import com.sleepycat.je.dbi.DatabaseImpl;
import com.sleepycat.je.dbi.SortedLSNTreeWalker;
import com.sleepycat.je.dbi.SortedLSNTreeWalker.TreeNodeProcessor;
import com.sleepycat.je.log.LogEntryType;
import com.sleepycat.je.utilint.DbLsn;

/**
 * Verify cleaner data structures
 */
public class VerifyUtils {

    private static final boolean DEBUG = false;

    /**
     * Compare the lsns referenced by a given Database to the lsns held
     * in the utilization profile. Assumes that the database and
     * environment is quiescent, and that there is no current cleaner
     * activity.
     */
    public static void checkLsns(Database db)
        throws DatabaseException {
    
        DatabaseImpl dbImpl = DbInternal.dbGetDatabaseImpl(db);
    
        /* Get all the lsns in the database. */
        GatherLSNs gatherLsns = new GatherLSNs();
        long rootLsn = dbImpl.getTree().getRootLsn();
        SortedLSNTreeWalker walker = 
            new SortedLSNTreeWalker(dbImpl,
                                    false, // don't remove from INList
                                    false, // don't set db state
                                    rootLsn,
                                    gatherLsns);
        walker.walk();
        Set lsnsInTree = gatherLsns.getLsns();
        lsnsInTree.add(new Long(rootLsn));
    
        /* Get all the files used by this database. */
        Iterator iter = lsnsInTree.iterator();
        Set fileNums = new HashSet();
    
        while (iter.hasNext()) {
            long lsn = ((Long) iter.next()).longValue();
            fileNums.add(new Long(DbLsn.getFileNumber(lsn)));
        }
    
        /* Gather up the obsolete lsns in these file summary lns */
        iter = fileNums.iterator();
        Set obsoleteLsns = new HashSet();
        UtilizationProfile profile =
            dbImpl.getDbEnvironment().getUtilizationProfile();
    
        while (iter.hasNext()) {
            Long fileNum = (Long) iter.next();
    
            PackedOffsets obsoleteOffsets = new PackedOffsets();
            TrackedFileSummary tfs =
                profile.getObsoleteDetail(fileNum,
                                          obsoleteOffsets, 
                                          false /* logUpdate */);
            PackedOffsets.Iterator obsoleteIter = obsoleteOffsets.iterator();
            while (obsoleteIter.hasNext()) {
        	long offset = obsoleteIter.next();
        	Long oneLsn = new Long(DbLsn.makeLsn(fileNum.longValue(),
        		                             offset));
                obsoleteLsns.add(oneLsn);
                if (DEBUG) {
                    System.out.println("Adding 0x" + 
                                       Long.toHexString(oneLsn.longValue()));
                }
            }
        }
    
        /* Check than none the lsns in the tree is in the UP. */
        boolean error = false;
        iter = lsnsInTree.iterator();
        while (iter.hasNext()) {
            Long lsn = (Long) iter.next();
            if (obsoleteLsns.contains(lsn)) {
                System.err.println("Obsolete lsns contains valid lsn " +
                                   DbLsn.getNoFormatString(lsn.longValue()));
                error = true;
            }
        }
    
        /* 
         * Check that none of the lsns in the file summary ln is in the
         * tree. 
         */
        iter = obsoleteLsns.iterator();
        while (iter.hasNext()) {
            Long lsn = (Long) iter.next();
            if (lsnsInTree.contains(lsn)) {
                System.err.println("Tree contains obsolete lsn " +
                                   DbLsn.getNoFormatString(lsn.longValue()));
                error = true;
            }
        }
    
        if (error) {
            throw new DatabaseException("Lsn mismatch");
        }
    } 

    private static class GatherLSNs implements TreeNodeProcessor {
        private Set lsns = new HashSet();
    
        public void processLSN(long childLSN, LogEntryType childType) {
            lsns.add(new Long(childLSN));
        }
    
        public Set getLsns() {
            return lsns;
        }
    }
}