Package org.teiid.query.sql.lang

Source Code of org.teiid.query.sql.lang.Command

/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership.  Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/

package org.teiid.query.sql.lang;

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import org.teiid.core.types.DataTypeManager;
import org.teiid.core.util.EquivalenceUtil;
import org.teiid.query.processor.ProcessorPlan;
import org.teiid.query.sql.LanguageObject;
import org.teiid.query.sql.symbol.ElementSymbol;
import org.teiid.query.sql.symbol.GroupSymbol;
import org.teiid.query.sql.symbol.SingleElementSymbol;
import org.teiid.query.sql.util.SymbolMap;
import org.teiid.query.sql.visitor.CommandCollectorVisitor;
import org.teiid.query.sql.visitor.SQLStringVisitor;


/**
* A Command is an interface for all the language objects that are at the root
* of a language object tree representing a SQL statement.  For instance, a
* Query command represents a SQL select query, an Update command represents a
* SQL update statement, etc.
*/
public abstract class Command implements LanguageObject {
 
  /**
   * Represents an unknown type of command
   */
  public static final int TYPE_UNKNOWN = 0;
 
  /**
   * Represents a SQL SELECT statement
   */
  public static final int TYPE_QUERY = 1;
 
  /**
   * Represents a SQL INSERT statement
   */
  public static final int TYPE_INSERT = 2;

  /**
   * Represents a SQL UPDATE statement
   */
  public static final int TYPE_UPDATE = 3;

  /**
   * Represents a SQL DELETE statement
   */
  public static final int TYPE_DELETE = 4;

  /**
   * Represents any SQL statement, wrapped as a string
   */
  public static final int TYPE_SQL = 5;

  /**
   * Represents a stored procedure command
   */
    public static final int TYPE_STORED_PROCEDURE = 6;
   
  /**
   * Represents a update stored procedure command
   */
    public static final int TYPE_UPDATE_PROCEDURE = 7;

    /**
     * Represents a batched sequence of UPDATE statements
     */
    public static final int TYPE_BATCHED_UPDATE = 9;
   
    public static final int TYPE_DYNAMIC = 10;
   
    public static final int TYPE_CREATE = 11;
   
    public static final int TYPE_DROP = 12;
   
    public static final int TYPE_TRIGGER_ACTION = 13;
   
    public static final int TYPE_ALTER_VIEW = 14;
   
    public static final int TYPE_ALTER_PROC = 15;
   
    public static final int TYPE_ALTER_TRIGGER = 16;

    private static List<SingleElementSymbol> updateCommandSymbol;
   
    /**
     * All temporary group IDs discovered while resolving this
     * command.  The key is a TempMetadataID and the value is an
     * ordered List of TempMetadataID representing the elements.
     */
    protected Map tempGroupIDs;
   
    private transient GroupContext externalGroups;

    private boolean isResolved;
   
  /** The option clause */
  private Option option;
 
  private ProcessorPlan plan;
 
  private SymbolMap correlatedReferences;
 
  private CacheHint cacheHint;
   
  /**
   * Return type of command to make it easier to build switch statements by command type.
   * @return Type from TYPE constants
   */ 
  public abstract int getType();
 
  /**
   * Get the correlated references to the containing scope only
   * @return
   */
  public SymbolMap getCorrelatedReferences() {
    return correlatedReferences;
  }
 
  public void setCorrelatedReferences(SymbolMap correlatedReferences) {
    this.correlatedReferences = correlatedReferences;
  }

    public void setTemporaryMetadata(Map metadata) {
        this.tempGroupIDs = metadata;
    }
   
    public Map getTemporaryMetadata() {
        return this.tempGroupIDs;
    }
   
    public void addExternalGroupToContext(GroupSymbol group) {
        getExternalGroupContexts().addGroup(group);
    }
   
    public void addExternalGroupsToContext(Collection<GroupSymbol> groups) {
        getExternalGroupContexts().getGroups().addAll(groups);
    }

    public void setExternalGroupContexts(GroupContext root) {
        if (root == null) {
            this.externalGroups = null;
        } else {
            this.externalGroups = (GroupContext)root.clone();
        }
    }
   
    public void pushNewResolvingContext(Collection<GroupSymbol> groups) {
        externalGroups = new GroupContext(externalGroups, new LinkedList<GroupSymbol>(groups));
    }

    public GroupContext getExternalGroupContexts() {
        if (externalGroups == null) {
            this.externalGroups = new GroupContext();
        }
        return this.externalGroups;
    }
   
    public List<GroupSymbol> getAllExternalGroups() {
        if (externalGroups == null) {
            return Collections.emptyList();
        }
       
        return externalGroups.getAllGroups();
    }

    /**
     * Indicates whether this command has been resolved or not -
     * attempting to resolve a command that has already been resolved
     * has undefined results.  Also, caution should be taken in modifying
     * a command which has already been resolved, as it could result in
     * adding unresolved components to a supposedly resolved command.
     * @return whether this command is resolved or not.
     */
    public boolean isResolved() {
        return this.isResolved;
    }

    /**
     * This command is intended to only be used by the QueryResolver.
     * @param isResolved whether this command is resolved or not
     */
    public void setIsResolved(boolean isResolved) {
        this.isResolved = isResolved;
    }
       
    public abstract Object clone();
   
    protected void copyMetadataState(Command copy) {
        if(this.getExternalGroupContexts() != null) {
            copy.externalGroups = (GroupContext)this.externalGroups.clone();
        }
        if(this.tempGroupIDs != null) {
            copy.setTemporaryMetadata(new HashMap(this.tempGroupIDs));
        }
       
        copy.setIsResolved(this.isResolved());
        copy.plan = this.plan;
        if (this.correlatedReferences != null) {
          copy.correlatedReferences = this.correlatedReferences.clone();
        }
        if(this.getOption() != null) {
            copy.setOption( (Option) this.getOption().clone() );
        }
        copy.cacheHint = this.cacheHint;
    }
   
    /**
     * Print the full tree of commands with indentation - useful for debugging
     * @return String String representation of command tree
     */
    public String printCommandTree() {
        StringBuffer str = new StringBuffer();
        printCommandTree(str, 0);
        return str.toString();
    }
   
    /**
     * Helper method to print command tree at given tab level
     * @param str String buffer to add command sub tree to
     * @param tabLevel Number of tabs to print this command at
     */
    protected void printCommandTree(StringBuffer str, int tabLevel) {
        // Add tabs
        for(int i=0; i<tabLevel; i++) {
            str.append("\t"); //$NON-NLS-1$
        }
       
        // Add this command
        str.append(toString());
        str.append("\n"); //$NON-NLS-1$
       
        // Add children recursively
        tabLevel++;
        for (Command subCommand : CommandCollectorVisitor.getCommands(this)) {
            subCommand.printCommandTree(str, tabLevel);
        }
    }
   
    // =========================================================================
    //                     O P T I O N      M E T H O D S
    // =========================================================================
   
    /**
     * Get the option clause for the query.
     * @return option clause
     */
    public Option getOption() {
        return option;
    }
   
    /**
     * Set the option clause for the query.
     * @param option New option clause
     */
    public void setOption(Option option) {
        this.option = option;
    }

  /**
   * Get the ordered list of all elements returned by this query.  These elements
   * may be ElementSymbols or ExpressionSymbols but in all cases each represents a
   * single column.
   * @return Ordered list of SingleElementSymbol
   */
  public abstract List<SingleElementSymbol> getProjectedSymbols();

  /**
   * Whether the results are cachable.
   * @return True if the results are cachable; false otherwise.
   */
  public abstract boolean areResultsCachable();
   
    public static List<SingleElementSymbol> getUpdateCommandSymbol() {
        if (updateCommandSymbol == null ) {
            ElementSymbol symbol = new ElementSymbol("Count"); //$NON-NLS-1$
            symbol.setType(DataTypeManager.DefaultDataClasses.INTEGER);
            updateCommandSymbol = Arrays.asList((SingleElementSymbol)symbol);
        }
        return updateCommandSymbol;
    }
   
    public ProcessorPlan getProcessorPlan() {
      return this.plan;
    }
   
    public void setProcessorPlan(ProcessorPlan plan) {
      this.plan = plan;
    }
   
    public CacheHint getCacheHint() {
    return cacheHint;
  }
   
    public void setCacheHint(CacheHint cacheHint) {
    this.cacheHint = cacheHint;
  }
   
    /**
     * Returns a string representation of an instance of this class.
     * @return String representation of object
     */
    public String toString() {
        return SQLStringVisitor.getSQLString(this);
    }
   
    protected boolean sameOptionAndHint(Command cmd) {
      return EquivalenceUtil.areEqual(this.cacheHint, cmd.cacheHint) &&
      EquivalenceUtil.areEqual(this.option, cmd.option);
    }
   
    public boolean returnsResultSet() {
        return false;
    }
}
TOP

Related Classes of org.teiid.query.sql.lang.Command

TOP
Copyright © 2015 www.massapi.com. All rights reserved.
All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.