The MultiKey is a lot of complicated code to optimize an obscure situation. I know it's obscure because there's not a single use of this class anywhere that I can find.

src/java/com/samskivert/depot/MultiKey.java

@@ -1,159 +0,0 @@
-//
-// $Id$
-//
-// Depot library - a Java relational persistence library
-// Copyright (C) 2006-2008 Michael Bayne and Pär Winzell
-// 
-// This library is free software; you can redistribute it and/or modify it
-// under the terms of the GNU Lesser General Public License as published
-// by the Free Software Foundation; either version 2.1 of the License, or
-// (at your option) any later version.
-//
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-// Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public
-// License along with this library; if not, write to the Free Software
-// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-
-package com.samskivert.depot;
-
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.Map;
-
-import com.google.common.collect.Maps;
-
-import com.samskivert.depot.clause.Where;
-import com.samskivert.depot.clause.WhereClause;
-import com.samskivert.depot.expression.SQLExpression;
-import com.samskivert.depot.impl.ExpressionVisitor;
-
-/**
- * A special form of {@link Where} clause that specifies an explicit range of database rows. It
- * does not implement {@link CacheKey} but it does implement {@link CacheInvalidator} which means
- * it can be sent into e.g. {@link DepotRepository#deleteAll} and have it clean up after itself.
- */
-public class MultiKey<T extends PersistentRecord> extends WhereClause
-    implements ValidatingCacheInvalidator
-{
-    /**
-     * Constructs a new single-column {@code MultiKey} with the given value range.
-     */
-    public MultiKey (Class<T> pClass, String ix, Comparable<?>... val)
-    {
-        this(pClass, new String[0], new Comparable[0], ix, val);
-    }
-
-    /**
-     * Constructs a new two-column {@code MultiKey} with the given value range.
-     */
-    public MultiKey (Class<T> pClass, String ix1, Comparable<?> val1, String ix2,
-        Comparable<?>... val2)
-    {
-        this(pClass, new String[] { ix1 }, new Comparable[] { val1 }, ix2, val2);
-    }
-
-    /**
-     * Constructs a new three-column {@code MultiKey} with the given value range.
-     */
-    public MultiKey (Class<T> pClass, String ix1, Comparable<?> val1,
-                     String ix2, Comparable<?> val2, String ix3, Comparable<?>... val3)
-    {
-        this(pClass, new String[] { ix1, ix2 }, new Comparable[] { val1, val2 }, ix3, val3);
-    }
-
-    /**
-     * Constructs a new multi-column {@code MultiKey} with the given value range.
-     * See {@link Key#Key(Class,String[],Comparable[])} for somewhat relevant comments.
-     */
-    public MultiKey (Class<T> pClass, String[] sFields, Comparable<?>[] sValues,
-                     String mField, Comparable<?>[] mValues)
-    {
-        if (sFields.length != sValues.length) {
-            throw new IllegalArgumentException(
-                "Key field and values arrays must be of equal length.");
-        }
-        _pClass = pClass;
-        _mField = mField;
-        _mValues = mValues;
-        _map = Maps.newHashMap();
-        for (int i = 0; i < sFields.length; i ++) {
-            _map.put(sFields[i], sValues[i]);
-        }
-    }
-
-    public Class<T> getPersistentClass ()
-    {
-        return _pClass;
-    }
-
-    public Map<String, Comparable<?>> getSingleFieldsMap ()
-    {
-        return _map;
-    }
-
-    public String getMultiField ()
-    {
-        return _mField;
-    }
-
-    public Comparable<?>[] getMultiValues ()
-    {
-        return _mValues;
-    }
-
-    // from WhereClause
-    public SQLExpression getWhereExpression ()
-    {
-        throw new RuntimeException("Not used");
-    }
-
-    // from SQLExpression
-    public void accept (ExpressionVisitor builder)
-    {
-        builder.visit(this);
-    }
-
-    // from SQLExpression
-    public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
-    {
-        // nothing to add
-    }
-
-    // from ValidatingCacheInvalidator
-    public void validateFlushType (Class<?> pClass)
-    {
-        if (!pClass.equals(_pClass)) {
-            throw new IllegalArgumentException(
-                "Class mismatch between persistent record and cache invalidator " +
-                "[record=" + pClass.getSimpleName() +
-                ", invtype=" + _pClass.getSimpleName() + "].");
-        }
-    }
-
-    // from CacheInvalidator
-    public void invalidate (PersistenceContext ctx)
-    {
-        // must be a hashmap for serializability
-        HashMap<String, Comparable<?>> newMap = Maps.newHashMap(_map);
-        for (Comparable<?> value : _mValues) {
-            newMap.put(_mField, value);
-            ctx.cacheInvalidate(new SimpleCacheKey(_pClass, newMap));
-        }
-    }
-
-    @Override // from WhereClause
-    public void validateQueryType (Class<?> pClass)
-    {
-        super.validateQueryType(pClass);
-        validateTypesMatch(pClass, _pClass);
-    }
-
-    protected String _mField;
-    protected Comparable<?>[] _mValues;
-    protected Class<T> _pClass;
-    protected Map<String, Comparable<?>> _map;
-}

src/java/com/samskivert/depot/impl/BuildVisitor.java

@@ -33,7 +33,6 @@ import com.samskivert.util.Tuple;
 
 import com.samskivert.depot.ByteEnum;
 import com.samskivert.depot.Key;
-import com.samskivert.depot.MultiKey;
 import com.samskivert.depot.PersistentRecord;
 import com.samskivert.depot.annotation.Computed;
 import com.samskivert.depot.clause.FieldDefinition;
@@ -137,45 +136,6 @@ public abstract class BuildVisitor implements ExpressionVisitor
         }
     }
 
-    public void visit (MultiKey<? extends PersistentRecord> key)
-    {
-        _builder.append(" where ");
-        boolean first = true;
-        for (Map.Entry<String, Comparable<?>> entry : key.getSingleFieldsMap().entrySet()) {
-            if (first) {
-                first = false;
-            } else {
-                _builder.append(" and ");
-            }
-            // A MultiKey's WHERE clause must mirror what's actually retrieved for the persistent
-            // object, so we turn on overrides here just as we do when expanding SELECT fields
-            boolean saved = _enableOverrides;
-            _enableOverrides = true;
-            appendRhsColumn(key.getPersistentClass(), entry.getKey());
-            _enableOverrides = saved;
-            if (entry.getValue() == null) {
-                _builder.append(" is null ");
-            } else {
-                _builder.append(" = ");
-                bindValue(entry.getValue());
-            }
-        }
-        if (!first) {
-            _builder.append(" and ");
-        }
-        appendRhsColumn(key.getPersistentClass(), key.getMultiField());
-        _builder.append(" in (");
-
-        Comparable<?>[] values = key.getMultiValues();
-        for (int ii = 0; ii < values.length; ii ++) {
-            if (ii > 0) {
-                _builder.append(", ");
-            }
-            bindValue(values[ii]);
-        }
-        _builder.append(")");
-    }
-
     public void visit (FunctionExp functionExp)
     {
         _builder.append(functionExp.getFunction());

src/java/com/samskivert/depot/impl/ExpressionVisitor.java

@@ -21,7 +21,6 @@
 package com.samskivert.depot.impl;
 
 import com.samskivert.depot.Key;
-import com.samskivert.depot.MultiKey;
 import com.samskivert.depot.PersistentRecord;
 
 import com.samskivert.depot.clause.FieldDefinition;
@@ -81,7 +80,6 @@ public interface ExpressionVisitor
     public void visit (ValueExp valueExp);
     public void visit (WhereClause where);
     public void visit (Key.Expression<? extends PersistentRecord> key);
-    public void visit (MultiKey<? extends PersistentRecord> key);
     public void visit (Exists<? extends PersistentRecord> exists);
     public void visit (SelectClause<? extends PersistentRecord> selectClause);
     public void visit (UpdateClause<? extends PersistentRecord> updateClause);