agent/src/share/classes/sun/jvm/hotspot/utilities/soql/SOQLEngine.java - platform/external/jetbrains/jdk8u_hotspot - Git at Google

 /*
  * Copyright (c) 2003, 2007, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code 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 General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */

 package sun.jvm.hotspot.utilities.soql;

 import java.util.*;
 import sun.jvm.hotspot.oops.*;
 import sun.jvm.hotspot.memory.*;
 import sun.jvm.hotspot.runtime.*;
 import sun.jvm.hotspot.utilities.*;

 /**
  * This is SOQL (Simple Object Query Language) engine. This
  * uses JavaScript engine for the "select" and "where" expression
  * parts.
  */
 public class SOQLEngine extends JSJavaScriptEngine {
    public static synchronized SOQLEngine getEngine() {
       if (soleInstance == null) {
          soleInstance = new SOQLEngine();
       }
       return soleInstance;
    }

    /**
       Query is of the form

          select &lt;java script code to select&gt;
          [ from [instanceof] &lt;class name&gt; [&lt;identifier&gt;]
            [ where &lt;java script boolean expression&gt; ]
          ]
    */
    public synchronized void executeQuery(String query, ObjectVisitor visitor)
                                                  throws SOQLException {
       debugPrint("query : " + query);
       StringTokenizer st = new StringTokenizer(query);
       if (st.hasMoreTokens()) {
          String first = st.nextToken();
          if (! first.equals("select") ) {
             throw new SOQLException("query syntax error: no 'select' clause");
          }
       } else {
          throw new SOQLException("query syntax error: no 'select' clause");
       }

       int selectStart = query.indexOf("select");
       int fromStart = query.indexOf("from");

       String selectExpr = null;
       String className = null;
       boolean isInstanceOf = false;
       String whereExpr = null;
       String identifier = null;

       if (fromStart != -1) {
          selectExpr = query.substring(selectStart + "select".length(), fromStart);
          st = new StringTokenizer(query.substring(fromStart + "from".length()));

          if (st.hasMoreTokens()) {
             String tmp = st.nextToken();
             if (tmp.equals("instanceof")) {
                isInstanceOf = true;
                if (! st.hasMoreTokens()) {
                   throw new SOQLException("no class name after 'instanceof'");
                }
                className = st.nextToken();
             } else {
                className = tmp;
             }
          } else {
             throw new SOQLException("query syntax error: class name must follow 'from'");
          }

          if (st.hasMoreTokens()) {
             identifier = st.nextToken();
             if (identifier.equals("where")) {
                throw new SOQLException("query syntax error: identifier should follow class name");
             }
             if (st.hasMoreTokens()) {
                String tmp = st.nextToken();
                if (! tmp.equals("where")) {
                   throw new SOQLException("query syntax error: 'where' clause expected after 'from' clause");
                }
                int whereEnd = query.lastIndexOf("where") + 5; // "where".length
                whereExpr = query.substring(whereEnd);
             }
          } else {
             throw new SOQLException("query syntax error: identifier should follow class name");
          }
       } else { // no from clause
          selectExpr = query.substring(selectStart + "select".length(), query.length());
       }

       executeQuery(new SOQLQuery(selectExpr, isInstanceOf, className, identifier, whereExpr), visitor);
    }

    private void executeQuery(SOQLQuery q, ObjectVisitor visitor) throws SOQLException {
       InstanceKlass kls = null;
       if (q.className != null) {
          kls = SystemDictionaryHelper.findInstanceKlass(q.className);
          if (kls == null) {
             throw new SOQLException(q.className + " is not found!");
          }
       }


       StringBuffer buf = new StringBuffer();
       buf.append("function result(");
       if (q.identifier != null) {
          buf.append(q.identifier);
       }
       buf.append(") { return ");
       buf.append(q.selectExpr.replace('\n', ' '));
       buf.append("; }");

       String selectCode = buf.toString();
       debugPrint(selectCode);
       String whereCode = null;
       if (q.whereExpr != null) {
          buf = new StringBuffer();
          buf.append("function filter(");
          buf.append(q.identifier);
          buf.append(") { return ");
          buf.append(q.whereExpr.replace('\n', ' '));
          buf.append("; }");
          whereCode = buf.toString();
          debugPrint(whereCode);
       } else {
          whereCode = "filter = null;";
       }

       beginQuery();
       // compile select expression and where condition
       evalString(selectCode, "", 1);
       evalString(whereCode,  "", 1);

       // iterate thru heap, if needed
       if (q.className != null) {
          try {
             iterateOops(kls, visitor, q.isInstanceOf);
          } finally {
             endQuery();
          }
       } else {
          // simple "select <expr>" query
          try {
             Object select = call("result", new Object[] {});
             visitor.visit(select);
          } catch (Exception e) {
             e.printStackTrace();
          }
       }
    }

    private void dispatchObject(Oop oop, ObjectVisitor visitor, boolean filterExists) {
       JSJavaObject jsObj = factory.newJSJavaObject(oop);
       Object[] args = new Object[] { jsObj };
       boolean b = true;

       try {
          if (filterExists) {
             Object res = call("filter", args);
             if (res instanceof Boolean) {
                b = ((Boolean)res).booleanValue();
             } else if (res instanceof Number) {
                b = ((Number)res).intValue() != 0;
             } else {
                b = (res != null);
             }
          }

          if (b) {
             Object select = call("result", args);
             visitor.visit(select);
          }
       } catch (Exception e) {
          throw new RuntimeException(e);
       }
    }

    private void iterateOops(final InstanceKlass ik, final ObjectVisitor visitor,
                             boolean includeSubtypes) {
       ObjectHeap oh = VM.getVM().getObjectHeap();
       oh.iterateObjectsOfKlass(new HeapVisitor() {
                     boolean filterExists;
                     public void prologue(long usedSize) {
                         filterExists = getScriptEngine().get("filter") != null;
                     }
                     public boolean doObj(Oop obj) {
                        dispatchObject(obj, visitor, filterExists);
                        return false;
                     }
                     public void epilogue() {}
                  }, ik, includeSubtypes);
    }

    // we create fresh ObjectReader and factory to avoid
    // excessive cache across queries.
    private void beginQuery() {
       objReader = new ObjectReader();
       factory = new JSJavaFactoryImpl();
    }

    // at the end of query we clear object reader cache
    // and factory cache
    private void endQuery() {
       objReader = null;
       factory = null;
    }

    protected ObjectReader getObjectReader() {
       return objReader;
    }

    protected JSJavaFactory getJSJavaFactory() {
       return factory;
    }

    protected boolean isQuitting() {
       return false;
    }

    protected void quit() {
       // do nothing
    }

    private static void debugPrint(String msg) {
       if (debug) System.out.println(msg);
    }

    private static final boolean debug;
    static {
       debug = System.getProperty("sun.jvm.hotspot.utilities.soql.SOQLEngine.debug") != null;
    }

    protected SOQLEngine() {
        super(debug);
        start();
    }

    private ObjectReader objReader;
    private JSJavaFactory factory;
    private static SOQLEngine soleInstance;
 }
	/*
	* Copyright (c) 2003, 2007, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code 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 General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*
	*/

	package sun.jvm.hotspot.utilities.soql;

	import java.util.*;
	import sun.jvm.hotspot.oops.*;
	import sun.jvm.hotspot.memory.*;
	import sun.jvm.hotspot.runtime.*;
	import sun.jvm.hotspot.utilities.*;

	/**
	* This is SOQL (Simple Object Query Language) engine. This
	* uses JavaScript engine for the "select" and "where" expression
	* parts.
	*/
	public class SOQLEngine extends JSJavaScriptEngine {
	public static synchronized SOQLEngine getEngine() {
	if (soleInstance == null) {
	soleInstance = new SOQLEngine();
	}
	return soleInstance;
	}

	/**
	Query is of the form

	select <java script code to select>
	[ from [instanceof] <class name> [<identifier>]
	[ where <java script boolean expression> ]
	]
	*/
	public synchronized void executeQuery(String query, ObjectVisitor visitor)
	throws SOQLException {
	debugPrint("query : " + query);
	StringTokenizer st = new StringTokenizer(query);
	if (st.hasMoreTokens()) {
	String first = st.nextToken();
	if (! first.equals("select") ) {
	throw new SOQLException("query syntax error: no 'select' clause");
	}
	} else {
	throw new SOQLException("query syntax error: no 'select' clause");
	}

	int selectStart = query.indexOf("select");
	int fromStart = query.indexOf("from");

	String selectExpr = null;
	String className = null;
	boolean isInstanceOf = false;
	String whereExpr = null;
	String identifier = null;

	if (fromStart != -1) {
	selectExpr = query.substring(selectStart + "select".length(), fromStart);
	st = new StringTokenizer(query.substring(fromStart + "from".length()));

	if (st.hasMoreTokens()) {
	String tmp = st.nextToken();
	if (tmp.equals("instanceof")) {
	isInstanceOf = true;
	if (! st.hasMoreTokens()) {
	throw new SOQLException("no class name after 'instanceof'");
	}
	className = st.nextToken();
	} else {
	className = tmp;
	}
	} else {
	throw new SOQLException("query syntax error: class name must follow 'from'");
	}

	if (st.hasMoreTokens()) {
	identifier = st.nextToken();
	if (identifier.equals("where")) {
	throw new SOQLException("query syntax error: identifier should follow class name");
	}
	if (st.hasMoreTokens()) {
	String tmp = st.nextToken();
	if (! tmp.equals("where")) {
	throw new SOQLException("query syntax error: 'where' clause expected after 'from' clause");
	}
	int whereEnd = query.lastIndexOf("where") + 5; // "where".length
	whereExpr = query.substring(whereEnd);
	}
	} else {
	throw new SOQLException("query syntax error: identifier should follow class name");
	}
	} else { // no from clause
	selectExpr = query.substring(selectStart + "select".length(), query.length());
	}

	executeQuery(new SOQLQuery(selectExpr, isInstanceOf, className, identifier, whereExpr), visitor);
	}

	private void executeQuery(SOQLQuery q, ObjectVisitor visitor) throws SOQLException {
	InstanceKlass kls = null;
	if (q.className != null) {
	kls = SystemDictionaryHelper.findInstanceKlass(q.className);
	if (kls == null) {
	throw new SOQLException(q.className + " is not found!");
	}
	}


	StringBuffer buf = new StringBuffer();
	buf.append("function result(");
	if (q.identifier != null) {
	buf.append(q.identifier);
	}
	buf.append(") { return ");
	buf.append(q.selectExpr.replace('\n', ' '));
	buf.append("; }");

	String selectCode = buf.toString();
	debugPrint(selectCode);
	String whereCode = null;
	if (q.whereExpr != null) {
	buf = new StringBuffer();
	buf.append("function filter(");
	buf.append(q.identifier);
	buf.append(") { return ");
	buf.append(q.whereExpr.replace('\n', ' '));
	buf.append("; }");
	whereCode = buf.toString();
	debugPrint(whereCode);
	} else {
	whereCode = "filter = null;";
	}

	beginQuery();
	// compile select expression and where condition
	evalString(selectCode, "", 1);
	evalString(whereCode, "", 1);

	// iterate thru heap, if needed
	if (q.className != null) {
	try {
	iterateOops(kls, visitor, q.isInstanceOf);
	} finally {
	endQuery();
	}
	} else {
	// simple "select <expr>" query
	try {
	Object select = call("result", new Object[] {});
	visitor.visit(select);
	} catch (Exception e) {
	e.printStackTrace();
	}
	}
	}

	private void dispatchObject(Oop oop, ObjectVisitor visitor, boolean filterExists) {
	JSJavaObject jsObj = factory.newJSJavaObject(oop);
	Object[] args = new Object[] { jsObj };
	boolean b = true;

	try {
	if (filterExists) {
	Object res = call("filter", args);
	if (res instanceof Boolean) {
	b = ((Boolean)res).booleanValue();
	} else if (res instanceof Number) {
	b = ((Number)res).intValue() != 0;
	} else {
	b = (res != null);
	}
	}

	if (b) {
	Object select = call("result", args);
	visitor.visit(select);
	}
	} catch (Exception e) {
	throw new RuntimeException(e);
	}
	}

	private void iterateOops(final InstanceKlass ik, final ObjectVisitor visitor,
	boolean includeSubtypes) {
	ObjectHeap oh = VM.getVM().getObjectHeap();
	oh.iterateObjectsOfKlass(new HeapVisitor() {
	boolean filterExists;
	public void prologue(long usedSize) {
	filterExists = getScriptEngine().get("filter") != null;
	}
	public boolean doObj(Oop obj) {
	dispatchObject(obj, visitor, filterExists);
	return false;
	}
	public void epilogue() {}
	}, ik, includeSubtypes);
	}

	// we create fresh ObjectReader and factory to avoid
	// excessive cache across queries.
	private void beginQuery() {
	objReader = new ObjectReader();
	factory = new JSJavaFactoryImpl();
	}

	// at the end of query we clear object reader cache
	// and factory cache
	private void endQuery() {
	objReader = null;
	factory = null;
	}

	protected ObjectReader getObjectReader() {
	return objReader;
	}

	protected JSJavaFactory getJSJavaFactory() {
	return factory;
	}

	protected boolean isQuitting() {
	return false;
	}

	protected void quit() {
	// do nothing
	}

	private static void debugPrint(String msg) {
	if (debug) System.out.println(msg);
	}

	private static final boolean debug;
	static {
	debug = System.getProperty("sun.jvm.hotspot.utilities.soql.SOQLEngine.debug") != null;
	}

	protected SOQLEngine() {
	super(debug);
	start();
	}

	private ObjectReader objReader;
	private JSJavaFactory factory;
	private static SOQLEngine soleInstance;
	}