LODAX.java

/*
 * Copyright (c) 2001-2017, Zoltan Farkas All Rights Reserved.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * Additionally licensed with:
 *
 * Licensed 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.spf4j.zel.instr;

import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import org.spf4j.zel.vm.AssignableValue;
import org.spf4j.zel.vm.ExecutionContext;
import org.spf4j.zel.vm.Program;
import org.spf4j.zel.vm.ZExecutionException;

@SuppressFBWarnings("CD_CIRCULAR_DEPENDENCY")
public final class LODAX extends Instruction implements SymbolRef {

  private static final long serialVersionUID = 1L;

  private final String symbol;

  public LODAX(final String symbol) {
    this.symbol = symbol;
  }

  public static void writeTo(final String symbol, final ExecutionContext context, final Object what)
          throws ZExecutionException {
    Program code = context.getProgram();
    Integer addr = code.getLocalSymbolTable().get(symbol);
    if (addr == null) {
      addr = code.getGlobalSymbolTable().get(symbol);
      if (addr == null) {
        throw new ZExecutionException("unalocated symbol encountered " + symbol);
      }
      context.globalPoke(addr, what);
    } else {
      context.localPoke(addr, what);
    }
  }

  @Override
  public int execute(final ExecutionContext context) {

    context.push(new AssignableValue() {

      @Override
      public void assign(final Object object) throws ZExecutionException {
        writeTo(symbol, context, object);
      }

      @Override
      public Object get() throws ZExecutionException {
        return LODX.readFrom(symbol, context);
      }
    });
    return 1;
  }

  @Override
  public String getSymbol() {
    return symbol;
  }

  @Override
  public Object[] getParameters() {
    return new Object[]{symbol};
  }

}