com.getbase.autoindexer.AutoIndexer.java Source code

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Here is the source code for com.getbase.autoindexer.AutoIndexer.java

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/*
 * Copyright (C) 2013 Jerzy Chalupski
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.getbase.autoindexer;

import com.google.common.base.Joiner;
import com.google.common.base.Predicate;
import com.google.common.collect.Sets;

import org.chalup.thneed.ManyToManyRelationship;
import org.chalup.thneed.ModelGraph;
import org.chalup.thneed.OneToManyRelationship;
import org.chalup.thneed.OneToOneRelationship;
import org.chalup.thneed.PolymorphicRelationship;
import org.chalup.thneed.RecursiveModelRelationship;
import org.chalup.thneed.RelationshipVisitor;

import java.util.Set;

public final class AutoIndexer {

    public static final String AUTO_INDEX_PREFIX = "auto_index";

    private AutoIndexer() {
    }

    private static final Joiner COLUMN_JOINER = Joiner.on(",");

    public static String getCreateStatement(SqliteIndex index) {
        return "CREATE INDEX " + index.getName() + " ON " + index.mTable + "(" + COLUMN_JOINER.join(index.mColumns)
                + ")";
    }

    public static Predicate<SqliteIndex> isIndexOnColumn(final String columnName) {
        return new Predicate<SqliteIndex>() {
            @Override
            public boolean apply(SqliteIndex index) {
                return index.mColumns.length == 1 && index.mColumns[0].equalsIgnoreCase(columnName);
            }
        };
    }

    public static Set<SqliteIndex> generateIndexes(ModelGraph<? extends DbTableModel> modelGraph) {
        final Set<SqliteIndex> indexes = Sets.newHashSet();

        modelGraph.accept(new RelationshipVisitor<DbTableModel>() {
            @Override
            public void visit(OneToManyRelationship<? extends DbTableModel> relationship) {
                DbTableModel model = relationship.mModel;
                DbTableModel referencedModel = relationship.mReferencedModel;

                indexes.add(new SqliteIndex(model.getDbTable(), relationship.mLinkedByColumn));
                indexes.add(new SqliteIndex(referencedModel.getDbTable(), relationship.mReferencedModelIdColumn));
            }

            @Override
            public void visit(OneToOneRelationship<? extends DbTableModel> relationship) {
                DbTableModel model = relationship.mModel;
                DbTableModel linkedModel = relationship.mLinkedModel;

                indexes.add(new SqliteIndex(linkedModel.getDbTable(), relationship.mLinkedByColumn));
                indexes.add(new SqliteIndex(model.getDbTable(), relationship.mParentModelIdColumn));
            }

            @Override
            public void visit(RecursiveModelRelationship<? extends DbTableModel> relationship) {
                DbTableModel model = relationship.mModel;

                indexes.add(new SqliteIndex(model.getDbTable(), relationship.mModelIdColumn));
                indexes.add(new SqliteIndex(model.getDbTable(), relationship.mGroupByColumn));
            }

            @Override
            public void visit(ManyToManyRelationship<? extends DbTableModel> relationship) {
                // no implementation necessary
            }

            @Override
            public void visit(PolymorphicRelationship<? extends DbTableModel> relationship) {
                DbTableModel model = relationship.mModel;
                indexes.add(new SqliteIndex(model.getDbTable(), relationship.mTypeColumnName,
                        relationship.mIdColumnName));

                for (DbTableModel dbTableModel : relationship.mPolymorphicModels.values()) {
                    indexes.add(new SqliteIndex(dbTableModel.getDbTable(), relationship.mPolymorphicModelIdColumn));
                }
            }
        });

        return indexes;
    }
}