Mercurial > jdk8-mips64-public > nashorn / file revision

 /*

  * Copyright (c) 2010, 2013, 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.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * 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

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  */

 package jdk.nashorn.internal.codegen;

 import java.io.Serializable;

 import java.util.Objects;

 import java.util.Set;

 import java.util.TreeSet;

 import jdk.nashorn.internal.ir.CompileUnitHolder;

 /**

   * Used to track split class compilation. Note that instances of the class are serializable, but all fields are

   * transient, making the serialized version of the class only useful for tracking the referential topology of other

   * AST nodes referencing the same or different compile units. We do want to preserve this topology though as

   * {@link CompileUnitHolder}s in a deserialized AST will undergo reinitialization.

   */

 public final class CompileUnit implements Comparable<CompileUnit>, Serializable {

     private static final long serialVersionUID = 1L;

     /** Current class name */

     private transient final String className;

     /** Current class generator */

     private transient ClassEmitter classEmitter;

     private transient long weight;

     private transient Class<?> clazz;

     private transient boolean isUsed;

     private static int emittedUnitCount;

     CompileUnit(final String className, final ClassEmitter classEmitter, final long initialWeight) {

         this.className    = className;

         this.weight       = initialWeight;

         this.classEmitter = classEmitter;

     }

     static Set<CompileUnit> createCompileUnitSet() {

         return new TreeSet<>();

     }

     static void increaseEmitCount() {

         emittedUnitCount++;

     }

     /**

      * Get the amount of emitted compile units so far in the system

      * @return emitted compile unit count

      */

     public static int getEmittedUnitCount() {

         return emittedUnitCount;

     }

     /**

      * Check if this compile unit is used

      * @return true if tagged as in use - i.e active code that needs to be generated

      */

     public boolean isUsed() {

         return isUsed;

     }

     /**

      * Check if a compile unit has code, not counting inits and clinits

      * @return true of if there is "real code" in the compile unit

      */

     public boolean hasCode() {

         return (classEmitter.getMethodCount() - classEmitter.getInitCount() - classEmitter.getClinitCount()) > 0;

     }

     /**

      * Tag this compile unit as used

      */

     public void setUsed() {

         this.isUsed = true;

     }

     /**

      * Return the class that contains the code for this unit, null if not

      * generated yet

      *

      * @return class with compile unit code

      */

     public Class<?> getCode() {

         return clazz;

     }

     /**

      * Set class when it exists. Only accessible from compiler

      * @param clazz class with code for this compile unit

      */

     void setCode(final Class<?> clazz) {

         Objects.requireNonNull(clazz);

         this.clazz = clazz;

         // Revisit this - refactor to avoid null-ed out non-final fields

         // null out emitter

         this.classEmitter = null;

     }

     /**

      * Add weight to this compile unit

      * @param w weight to add

      */

     void addWeight(final long w) {

         this.weight += w;

     }

     /**

      * Check if this compile unit can hold {@code weight} more units of weight

      * @param w weight to check if can be added

      * @return true if weight fits in this compile unit

      */

     public boolean canHold(final long w) {

         return (this.weight + w) < Splitter.SPLIT_THRESHOLD;

     }

     /**

      * Get the class emitter for this compile unit

      * @return class emitter

      */

     public ClassEmitter getClassEmitter() {

         return classEmitter;

     }

     /**

      * Get the class name for this compile unit

      * @return the class name

      */

     public String getUnitClassName() {

         return className;

     }

     private static String shortName(final String name) {

         return name == null ? null : name.lastIndexOf('/') == -1 ? name : name.substring(name.lastIndexOf('/') + 1);

     }

     @Override

     public String toString() {

         final String methods = classEmitter != null ? classEmitter.getMethodNames().toString() : "<anon>";

         return "[CompileUnit className=" + shortName(className) + " weight=" + weight + '/' + Splitter.SPLIT_THRESHOLD + " hasCode=" + methods + ']';

     }

     @Override

     public int compareTo(final CompileUnit o) {

         return className.compareTo(o.className);

     }

 }