/*

 * Copyright 2000-2005 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

package sun.jvm.hotspot.code;

import java.io.*;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.oops.*;

import sun.jvm.hotspot.runtime.*;

import sun.jvm.hotspot.utilities.*;

/** ScopeDescs contain the information that makes source-level

    debugging of nmethods possible; each scopeDesc describes a method

    activation */

public class ScopeDesc {

  /** NMethod information */

  private NMethod code;

  private Method  method;

  private int     bci;

  /** Decoding offsets */

  private int     decodeOffset;

  private int     senderDecodeOffset;

  private int     localsDecodeOffset;

  private int     expressionsDecodeOffset;

  private int     monitorsDecodeOffset;

  /** Scalar replaced bjects pool */

  private List    objects; // ArrayList<ScopeValue>

  public ScopeDesc(NMethod code, int decodeOffset) {

    this.code = code;

    this.decodeOffset = decodeOffset;

    this.objects      = decodeObjectValues(DebugInformationRecorder.SERIALIZED_NULL);

    // Decode header

    DebugInfoReadStream stream  = streamAt(decodeOffset);

    senderDecodeOffset = stream.readInt();

    method = (Method) VM.getVM().getObjectHeap().newOop(stream.readOopHandle());

    // Decode offsets for body and sender

    localsDecodeOffset      = stream.readInt();

    expressionsDecodeOffset = stream.readInt();

    monitorsDecodeOffset    = stream.readInt();

  }

  public ScopeDesc(NMethod code, int decodeOffset, int objectDecodeOffset) {

    this.code = code;

    this.decodeOffset = decodeOffset;

    this.objects      = decodeObjectValues(objectDecodeOffset);

    // Decode header

    DebugInfoReadStream stream  = streamAt(decodeOffset);

    senderDecodeOffset = stream.readInt();

    method = (Method) VM.getVM().getObjectHeap().newOop(stream.readOopHandle());

    // Decode offsets for body and sender

    localsDecodeOffset      = stream.readInt();

    expressionsDecodeOffset = stream.readInt();

    monitorsDecodeOffset    = stream.readInt();

  }

  public NMethod getNMethod() { return code; }

  public Method getMethod() { return method; }

  public int    getBCI()    { return bci;    }

  /** Returns a List<ScopeValue> */

  public List getLocals() {

    return decodeScopeValues(localsDecodeOffset);

  }

  /** Returns a List<ScopeValue> */

  public List getExpressions() {

    return decodeScopeValues(expressionsDecodeOffset);

  }

  /** Returns a List<MonitorValue> */

  public List getMonitors() {

    return decodeMonitorValues(monitorsDecodeOffset);

  }

  /** Returns a List<MonitorValue> */

  public List getObjects() {

    return objects;

  }

  /** Stack walking. Returns null if this is the outermost scope. */

  public ScopeDesc sender() {

    if (isTop()) {

      return null;

    }

    return new ScopeDesc(code, senderDecodeOffset);

  }

  /** Returns where the scope was decoded */

  public int getDecodeOffset() {

    return decodeOffset;

  }

  /** Tells whether sender() returns null */

  public boolean isTop() {

    return (senderDecodeOffset == DebugInformationRecorder.SERIALIZED_NULL);

  }

  public boolean equals(Object arg) {

    if (arg == null) {

      return false;

    }

    if (!(arg instanceof ScopeDesc)) {

      return false;

    }

    ScopeDesc sd = (ScopeDesc) arg;

    return (sd.method.equals(method) && (sd.bci == bci));

  }

  public void printValue() {

    printValueOn(System.out);

  }

  public void printValueOn(PrintStream tty) {

    tty.print("ScopeDesc for ");

    method.printValueOn(tty);

    tty.println(" @bci " + bci);

  }

  // FIXME: add more accessors

  //--------------------------------------------------------------------------------

  // Internals only below this point

  //

  private DebugInfoReadStream streamAt(int decodeOffset) {

    return new DebugInfoReadStream(code, decodeOffset, objects);

  }

  /** Returns a List<ScopeValue> or null if no values were present */

  private List decodeScopeValues(int decodeOffset) {

    if (decodeOffset == DebugInformationRecorder.SERIALIZED_NULL) {

      return null;

    }

    DebugInfoReadStream stream = streamAt(decodeOffset);

    int length = stream.readInt();

    List res = new ArrayList(length);

    for (int i = 0; i < length; i++) {

      res.add(ScopeValue.readFrom(stream));

    }

    return res;

  }

  /** Returns a List<MonitorValue> or null if no values were present */

  private List decodeMonitorValues(int decodeOffset) {

    if (decodeOffset == DebugInformationRecorder.SERIALIZED_NULL) {

      return null;

    }

    DebugInfoReadStream stream = streamAt(decodeOffset);

    int length = stream.readInt();

    List res = new ArrayList(length);

    for (int i = 0; i < length; i++) {

      res.add(new MonitorValue(stream));

    }

    return res;

  }

  /** Returns a List<ObjectValue> or null if no values were present */

  private List decodeObjectValues(int decodeOffset) {

    if (decodeOffset == DebugInformationRecorder.SERIALIZED_NULL) {

      return null;

    }

    List res = new ArrayList();

    DebugInfoReadStream stream = new DebugInfoReadStream(code, decodeOffset, res);

    int length = stream.readInt();

    for (int i = 0; i < length; i++) {

      // Objects values are pushed to 'res' array during read so that

      // object's fields could reference it (OBJECT_ID_CODE).

      ScopeValue.readFrom(stream);

      // res.add(ScopeValue.readFrom(stream));

    }

    Assert.that(res.size() == length, "inconsistent debug information");

    return res;

  }

}