content: /*******************************************************************************
   * Copyright (c) 2009, 2019 Mountainminds GmbH & Co. KG and Contributors
   * All rights reserved. This program and the accompanying materials
   * are made available under the terms of the Eclipse Public License v1.0
   * which accompanies this distribution, and is available at
   * http://www.eclipse.org/legal/epl-v10.html
   *
   * Contributors:
   *    Marc R. Hoffmann - initial API and implementation
   *    
   *******************************************************************************/
  package org.jacoco.core.internal.instr;
  
  import org.jacoco.core.internal.flow.ClassProbesAdapter;
  import org.jacoco.core.runtime.IExecutionDataAccessorGenerator;
  import org.objectweb.asm.ClassReader;
  import org.objectweb.asm.Opcodes;
  
  /**
   * Factory to find a suitable strategy to access the probe array for a given
   * class.
   */
  public final class ProbeArrayStrategyFactory {
  
  	private ProbeArrayStrategyFactory() {
  	}
  
  	/**
  	 * Creates a suitable strategy instance for the class described by the given
  	 * reader. Created instance must be used only to process a class or
  	 * interface for which it has been created and must be used only once.
  	 *
  	 * @param classId
  	 *            class identifier
  	 * @param reader
  	 *            reader to get information about the class
  	 * @param accessorGenerator
  	 *            accessor to the coverage runtime
  	 * @return strategy instance
  	 */
  	public static IProbeArrayStrategy createFor(final long classId,
  			final ClassReader reader,
  			final IExecutionDataAccessorGenerator accessorGenerator) {
  
  		final String className = reader.getClassName();
  		final int version = InstrSupport.getMajorVersion(reader);
  
  		if (isInterfaceOrModule(reader)) {
  			final ProbeCounter counter = getProbeCounter(reader);
  			if (counter.getCount() == 0) {
  				return new NoneProbeArrayStrategy();
  			}
  			if (version >= Opcodes.V11 && counter.hasMethods()) {
  				return new CondyProbeArrayStrategy(className, true, classId,
  						accessorGenerator);
  			}
  			if (version >= Opcodes.V1_8 && counter.hasMethods()) {
  				return new InterfaceFieldProbeArrayStrategy(className, classId,
  						counter.getCount(), accessorGenerator);
  			} else {
  				return new LocalProbeArrayStrategy(className, classId,
  						counter.getCount(), accessorGenerator);
  			}
  		} else {
  			if (version >= Opcodes.V11) {
  				return new CondyProbeArrayStrategy(className, false, classId,
  						accessorGenerator);
  			}
  			return new ClassFieldProbeArrayStrategy(className, classId,
  					InstrSupport.needsFrames(version), accessorGenerator);
  		}
  	}
  
  	private static boolean isInterfaceOrModule(final ClassReader reader) {
  		return (reader.getAccess()
  				& (Opcodes.ACC_INTERFACE | Opcodes.ACC_MODULE)) != 0;
  	}
  
  	private static ProbeCounter getProbeCounter(final ClassReader reader) {
  		final ProbeCounter counter = new ProbeCounter();
  		reader.accept(new ClassProbesAdapter(counter, false), 0);
  		return counter;
  	}
  
  }
  