PrepareCommand.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
// under the License.

package org.apache.doris.nereids.trees.plans.commands;

import org.apache.doris.analysis.StmtType;
import org.apache.doris.catalog.Column;
import org.apache.doris.mysql.MysqlCommand;
import org.apache.doris.nereids.StatementContext;
import org.apache.doris.nereids.trees.expressions.Placeholder;
import org.apache.doris.nereids.trees.expressions.Slot;
import org.apache.doris.nereids.trees.expressions.SlotReference;
import org.apache.doris.nereids.trees.plans.PlanType;
import org.apache.doris.nereids.trees.plans.commands.insert.InsertIntoTableCommand;
import org.apache.doris.nereids.trees.plans.logical.LogicalPlan;
import org.apache.doris.nereids.trees.plans.visitor.PlanVisitor;
import org.apache.doris.nereids.types.DataType;
import org.apache.doris.qe.ConnectContext;
import org.apache.doris.qe.OriginStatement;
import org.apache.doris.qe.PreparedStatementContext;
import org.apache.doris.qe.ResultSetMetaData;
import org.apache.doris.qe.StmtExecutor;

import com.google.common.collect.Lists;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import java.util.ArrayList;
import java.util.List;

/**
 * Prepared Statement
 */
public class PrepareCommand extends Command {
    private static final Logger LOG = LogManager.getLogger(PrepareCommand.class);

    private final List<Placeholder> placeholders = new ArrayList<>();
    private final LogicalPlan logicalPlan;

    private final String name;

    private final OriginStatement originalStmt;

    /**
     * constructor
     * @param name the statement name which represents statement id for prepared statement
     * @param plan the inner statement
     * @param placeholders the parameters for this prepared statement
     * @param originalStmt original statement from StmtExecutor
     */
    public PrepareCommand(String name, LogicalPlan plan, List<Placeholder> placeholders,
                OriginStatement originalStmt) {
        super(PlanType.PREPARED_COMMAND);
        this.logicalPlan = plan;
        this.placeholders.addAll(placeholders);
        this.name = name;
        this.originalStmt = originalStmt;
    }

    public String getName() {
        return name;
    }

    public List<Placeholder> getPlaceholders() {
        return placeholders;
    }

    public int placeholderCount() {
        return placeholders.size();
    }

    public LogicalPlan getLogicalPlan() {
        return logicalPlan;
    }

    public OriginStatement getOriginalStmt() {
        return originalStmt;
    }

    /**
     * return the labels of parameters
     */
    public List<String> getLabels() {
        List<String> labels = new ArrayList<>();
        for (Placeholder parameter : placeholders) {
            labels.add("$" + parameter.getPlaceholderId().asInt());
        }
        return labels;
    }

    // register prepared statement with attached statement id
    @Override
    public void run(ConnectContext ctx, StmtExecutor executor) throws Exception {
        List<String> labels = getLabels();
        StatementContext statementContext = ctx.getStatementContext();
        statementContext.setPrepareStage(true);
        List<Slot> slots;
        if (logicalPlan instanceof Command) {
            ResultSetMetaData md = ((Command) logicalPlan).getResultSetMetaData();
            slots = Lists.newArrayList();
            for (Column c : md.getColumns()) {
                slots.add(new SlotReference(c.getName(), DataType.fromCatalogType(c.getType())));
            }
        } else {
            slots = executor.planPrepareStatementSlots();
        }
        // register prepareStmt
        if (LOG.isDebugEnabled()) {
            LOG.debug("add prepared statement {}, isBinaryProtocol {}",
                    name, ctx.getCommand() == MysqlCommand.COM_STMT_PREPARE);
        }
        if (logicalPlan instanceof InsertIntoTableCommand
                    && ((InsertIntoTableCommand) logicalPlan).getLabelName().isPresent()) {
            throw new org.apache.doris.common.UserException("Only support prepare InsertStmt without label now");
        }
        ctx.addPreparedStatementContext(name,
                new PreparedStatementContext(this, ctx, ctx.getStatementContext(), name));
        if (ctx.getCommand() == MysqlCommand.COM_STMT_PREPARE && !ctx.isProxy()) {
            executor.sendStmtPrepareOK(Integer.parseInt(name), labels, slots);
        }
    }

    @Override
    public <R, C> R accept(PlanVisitor<R, C> visitor, C context) {
        return visitor.visit(this, context);
    }

    public PrepareCommand withPlaceholders(List<Placeholder> placeholders) {
        return new PrepareCommand(this.name, this.logicalPlan, placeholders, this.originalStmt);
    }

    @Override
    public StmtType stmtType() {
        return StmtType.PREPARE;
    }
}