org.apache.tajo.schema.QualifiedIdentifier.java Source code

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Here is the source code for org.apache.tajo.schema.QualifiedIdentifier.java

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/*
 * Lisensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.tajo.schema;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Function;
import com.google.common.collect.Collections2;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import org.apache.tajo.common.ProtoObject;
import org.apache.tajo.common.TajoDataTypes.IdentifierProto;
import org.apache.tajo.common.TajoDataTypes.QualifiedIdentifierProto;
import org.apache.tajo.util.StringUtils;

import javax.annotation.Nullable;
import java.util.Collection;
import java.util.Objects;

import static org.apache.tajo.schema.IdentifierPolicy.DefaultPolicy;

/**
 * Represents a qualified identifier. In other words, it represents identifiers for
 * all kinds of of database objects, such as databases, tables, and columns.
 */
public class QualifiedIdentifier implements ProtoObject<QualifiedIdentifierProto> {
    private ImmutableList<Identifier> names;

    private QualifiedIdentifier(Collection<Identifier> names) {
        this.names = ImmutableList.copyOf(names);
    }

    /**
     * Return a raw string representation for an identifier, which is equivalent to ones used in SQL statements.
     *
     * @param policy IdentifierPolicy
     * @return Raw identifier string
     */
    public String raw(final IdentifierPolicy policy) {
        return StringUtils.join(names, "" + policy.getIdentifierSeperator(), new Function<Identifier, String>() {
            @Override
            public String apply(@Nullable Identifier identifier) {
                return identifier.raw(policy);
            }
        });
    }

    public String interned() {
        return interned(DefaultPolicy());
    }

    /**
     * Raw string of qualified identifier
     * @param policy Identifier Policy
     * @return raw string
     */
    public String interned(final IdentifierPolicy policy) {
        return StringUtils.join(names, "" + policy.getIdentifierSeperator(), new Function<Identifier, String>() {
            @Override
            public String apply(@Nullable Identifier identifier) {
                return identifier.interned(policy);
            }
        });
    }

    @Override
    public String toString() {
        return interned(DefaultPolicy());
    }

    @Override
    public int hashCode() {
        return Objects.hash(names);
    }

    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj instanceof QualifiedIdentifier) {
            QualifiedIdentifier other = (QualifiedIdentifier) obj;
            return names.equals(other.names);
        }

        return false;
    }

    public static QualifiedIdentifier $(Collection<Identifier> names) {
        return new QualifiedIdentifier(ImmutableList.copyOf(names));
    }

    public static QualifiedIdentifier $(Identifier... names) {
        return new QualifiedIdentifier(ImmutableList.copyOf(names));
    }

    public static QualifiedIdentifier fromProto(QualifiedIdentifierProto proto) {
        Collection<Identifier> ids = Collections2.transform(proto.getNamesList(),
                new Function<IdentifierProto, Identifier>() {
                    @Override
                    public Identifier apply(@Nullable IdentifierProto identifierProto) {
                        return Identifier.fromProto(identifierProto);
                    }
                });
        return new QualifiedIdentifier(ids);
    }

    /**
     * It takes interned strings. It assumes all parameters already stripped. It is used only for tests.
     * @param names interned strings
     * @return QualifiedIdentifier
     */
    @VisibleForTesting
    public static QualifiedIdentifier $(String... names) {
        final ImmutableList.Builder<Identifier> builder = ImmutableList.builder();
        for (String n : names) {
            for (String split : n.split(StringUtils.escapeRegexp("" + DefaultPolicy().getIdentifierSeperator()))) {
                builder.add(Identifier._(split, IdentifierUtil.isShouldBeQuoted(split)));
            }
        }
        return new QualifiedIdentifier(builder.build());
    }

    @Override
    public QualifiedIdentifierProto getProto() {
        return QualifiedIdentifierProto.newBuilder()
                .addAllNames(Iterables.transform(names, new Function<Identifier, IdentifierProto>() {
                    @Override
                    public IdentifierProto apply(@Nullable Identifier identifier) {
                        return identifier.getProto();
                    }
                })).build();
    }
}