asterix-bad/src/main/java/org/apache/asterix/bad/lang/statement/CreateContinuousChannelStatement.java

/*
 * Licensed 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
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package org.apache.asterix.bad.lang.statement;

import org.apache.asterix.app.translator.QueryTranslator;
import org.apache.asterix.common.exceptions.MetadataException;
import org.apache.asterix.common.metadata.DataverseName;
import org.apache.asterix.lang.common.base.Expression;
import org.apache.asterix.lang.common.expression.LiteralExpr;
import org.apache.asterix.lang.common.literal.StringLiteral;
import org.apache.asterix.lang.common.statement.CreateFunctionStatement;
import org.apache.asterix.lang.common.struct.Identifier;
import org.apache.asterix.lang.sqlpp.parser.SqlppParserFactory;
import org.apache.asterix.lang.sqlpp.rewrites.SqlppRewriterFactory;
import org.apache.asterix.metadata.MetadataManager;
import org.apache.asterix.metadata.MetadataTransactionContext;
import org.apache.asterix.metadata.declared.MetadataProvider;
import org.apache.asterix.metadata.entities.Function;
import org.apache.asterix.translator.IStatementExecutor;

public class CreateContinuousChannelStatement extends AbstractCreateChannelStatement {

    private CreateFunctionStatement stmt;

    public CreateContinuousChannelStatement(DataverseName dataverseName, Identifier channelName, Expression period,
            boolean push, CreateFunctionStatement stmt) {
        super(dataverseName, channelName, period, push);
        this.stmt = stmt;
    }

    @Override
    protected void initialize(IStatementExecutor statementExecutor, MetadataProvider metadataProvider,
            MetadataTransactionContext mdTxnCtx) throws Exception {
        // Creates function
        SqlppRewriterFactory fact = new SqlppRewriterFactory(new SqlppParserFactory());
        ((QueryTranslator) statementExecutor).handleCreateFunctionStatement(metadataProvider, stmt,
                fact.createStatementRewriter());
        this.function = stmt.getFunctionSignature();

        // Check whether function exists
        Function lookup = MetadataManager.INSTANCE.getFunction(mdTxnCtx, function);
        if (lookup == null) {
            throw new MetadataException(" Unknown function " + function.getName());
        }

        if (period != null) {
            if (!period.getFunctionSignature().getName().equals("duration")) {
                throw new MetadataException("Expected argument period as a duration, but got "
                        + period.getFunctionSignature().getName() + ".");
            }
            duration = ((StringLiteral) ((LiteralExpr) period.getExprList().get(0)).getValue()).getValue();
        } else {
            duration = "";
        }
    }
}