xref: /titanic_41/usr/src/lib/libdtrace_jni/java/src/org/opensolaris/os/dtrace/PrintfRecord.java (revision e77b06d21580f630e0a7c437495ab283d3672828)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * ident	"%Z%%M%	%I%	%E% SMI"
 */
package org.opensolaris.os.dtrace;

import java.io.*;
import java.beans.*;
import java.util.*;

/**
 * A formatted string generated by the DTrace {@code printf()} action.
 * <p>
 * Immutable.  Supports persistence using {@link java.beans.XMLEncoder}.
 *
 * @author Tom Erickson
 */
public final class PrintfRecord implements Record, Serializable,
	Comparable <PrintfRecord> {
    static final long serialVersionUID = 727237355963977675L;

    static {
	try {
	    BeanInfo info = Introspector.getBeanInfo(PrintfRecord.class);
	    PersistenceDelegate persistenceDelegate =
		    new DefaultPersistenceDelegate(
		    new String[] {"records", "formattedString"})
	    {
		/*
		 * Need to prevent DefaultPersistenceDelegate from using
		 * overridden equals() method, resulting in a
		 * StackOverFlowError.  Revert to PersistenceDelegate
		 * implementation.  See
		 * http://forum.java.sun.com/thread.jspa?threadID=
		 * 477019&tstart=135
		 */
		protected boolean
		mutatesTo(Object oldInstance, Object newInstance)
		{
		    return (newInstance != null && oldInstance != null &&
			    oldInstance.getClass() == newInstance.getClass());
		}
	    };
	    BeanDescriptor d = info.getBeanDescriptor();
	    d.setValue("persistenceDelegate", persistenceDelegate);
	} catch (IntrospectionException e) {
	    System.out.println(e);
	}
    }

    /** @serial */
    private List <ValueRecord> records;
    /** @serial */
    private String formattedString;

    // package-level access, called by ProbeData
    PrintfRecord()
    {
	records = new ArrayList <ValueRecord> ();
    }

    /**
     * Creates a record with the unformatted elements passed to the
     * DTrace {@code printf()} action and the resulting formatted
     * output.  Supports XML persistence.
     *
     * @param v variable number of unformatted elements passed to the
     * DTrace {@code printf()} action
     * @param s formatted {@code printf()} output
     * @throws NullPointerException if the given list or any of its
     * elements is {@code null}, or if the given formatted string is
     * {@code null}
     */
    public
    PrintfRecord(List <ValueRecord> v, String s)
    {
	formattedString = s;
	records = new ArrayList <ValueRecord> (v.size());
	records.addAll(v);
	validate();
    }

    private final void
    validate()
    {
	if (formattedString == null) {
	    throw new NullPointerException("formatted string is null");
	}
	if (records == null) {
	    throw new NullPointerException("list of format args is null");
	}
	for (ValueRecord r : records) {
	    if (r == null) {
		throw new NullPointerException("format arg is null");
	    }
	}
    }

    /**
     * Called by ProbeData code to populate record list.
     *
     * @throws NullPointerException if o is null
     */
    void
    addUnformattedElement(ScalarRecord rec)
    {
	records.add(rec);
    }

    /**
     * Gets the formatted string output of the DTrace {@code printf()}
     * action.
     *
     * @return non-null formatted string output of the DTrace {@code
     * printf()} action
     */
    public String
    getFormattedString()
    {
	return formattedString;
    }

    /**
     * Package level access; called by ProbeData
     */
    void
    setFormattedString(String s)
    {
	if (s == null) {
	    throw new NullPointerException("formatted string is null");
	}
	formattedString = s;
    }

    /**
     * Gets the unfomatted elements passed to the DTrace {@code
     * printf()} action after the format string.
     *
     * @return non-null, unmodifiable list of unformatted elements
     * passed to the DTrace {@code printf()} action that generated this
     * record, in the order they appear in the argument list after the
     * format string
     */
    public List <ValueRecord>
    getRecords()
    {
	return Collections. <ValueRecord> unmodifiableList(records);
    }

    /**
     * Gets the number of DTrace {@code printf()} unformatted elements
     * (arguments following the format string).  For example, the
     * following action
     * <pre><code>
     *    printf("%s %d\n", "cat", 9);
     * </code></pre>
     * generates a {@code PrintfRecord} with a record count of two.
     *
     * @return the number of unformatted elements passed to the DTrace
     * {@code printf()} action that generated this record.
     */
    public int
    getRecordCount()
    {
	return records.size();
    }

    /**
     * Gets the unformatted element passed to the DTrace {@code
     * printf()} action at the given offset in the {@code printf()}
     * argument list after the format string, starting at offset zero
     * for the first unformatted element.
     *
     * @return non-null record representing the unformatted {@code
     * printf()} element at the given index (using the same order that
     * they appear in the {@code printf()} argument list)
     * @throws ArrayIndexOutOfBoundsException if the given index is
     * out of range (index < 0 || index >= getRecordCount())
     */
    public ValueRecord
    getRecord(int i)
    {
	return records.get(i);
    }

    /**
     * Compares the specified object with this {@code PrintfRecord} for
     * equality. Returns {@code true} if and only if the specified
     * object is also a {@code PrintfRecord} and both records have the
     * same formatted string and underlying data elements.
     *
     * @return {@code true} if and only if the specified object is also
     * a {@code PrintfRecord} and both the formatted strings <i>and</i>
     * the underlying data elements of both records are equal
     */
    @Override
    public boolean
    equals(Object o)
    {
	if (o instanceof PrintfRecord) {
	    PrintfRecord r = (PrintfRecord)o;
	    return (records.equals(r.records) &&
		    formattedString.equals(r.formattedString));
	}
	return false;
    }

    /**
     * Overridden to ensure that equal instances have equal hash codes.
     */
    @Override
    public int
    hashCode()
    {
	int hash = 17;
	hash = (37 * hash) + records.hashCode();
	hash = (37 * hash) + formattedString.hashCode();
	return hash;
    }

    /**
     * Compares the formatted string value of this record with that of
     * the given record. Note that ordering {@code printf} records by
     * their string values is incompatible with {@link #equals(Object o)
     * equals()}, which also checks the underlying data elements for
     * equality.
     *
     * @return a negative number, 0, or a positive number as this
     * record's formatted string is lexicographically less than, equal
     * to, or greater than the given record's formatted string
     */
    public int
    compareTo(PrintfRecord r)
    {
	return formattedString.compareTo(r.formattedString);
    }

    private void
    readObject(ObjectInputStream s)
            throws IOException, ClassNotFoundException
    {
	s.defaultReadObject();
	// Defensively copy record list before validating
	if (records == null) {
	    throw new InvalidObjectException("record list is null");
	}
	List <ValueRecord> copy = new ArrayList <ValueRecord> (records.size());
	copy.addAll(records);
	records = copy;
	// check invariants
	try {
	    validate();
	} catch (Exception e) {
	    InvalidObjectException x = new InvalidObjectException(
		    e.getMessage());
	    x.initCause(e);
	    throw x;
	}
    }

    /**
     * Gets the formatted string output of the DTrace {@code printf()}
     * action.
     */
    public String
    toString()
    {
	return formattedString;
    }
}