content: /*
   * Copyright (C) 2007 The Android Open Source Project
   *
   * 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 com.taobao.android.dx.dex.code;
  
  import com.taobao.android.dx.dex.DexOptions;
  import java.util.ArrayList;
  
  /**
   * Destination for {@link DalvInsn} instances being output. This class
   * receives and collects instructions in two pieces &mdash; a primary
   * list and a suffix (generally consisting of adjunct data referred to
   * by the primary list, such as switch case tables) &mdash; which it
   * merges and emits back out in the form of a {@link DalvInsnList}
   * instance.
   */
  public final class OutputCollector {
      /**
       * {@code non-null;} the associated finisher (which holds the instruction
       * list in-progress)
       */
      private final OutputFinisher finisher;
  
      /**
       * {@code null-ok;} suffix for the output, or {@code null} if the suffix
       * has been appended to the main output (by {@link #appendSuffixToOutput})
       */
      private ArrayList<DalvInsn> suffix;
  
      /**
       * Constructs an instance.
       *
       * @param dexOptions {@code non-null;} options for dex output
       * @param initialCapacity {@code >= 0;} initial capacity of the output list
       * @param suffixInitialCapacity {@code >= 0;} initial capacity of the output
       * suffix
       * @param regCount {@code >= 0;} register count for the method
       * @param paramSize size, in register units, of all the parameters for this method
       */
      public OutputCollector(DexOptions dexOptions, int initialCapacity, int suffixInitialCapacity,
              int regCount, int paramSize) {
          this.finisher = new OutputFinisher(dexOptions, initialCapacity, regCount, paramSize);
          this.suffix = new ArrayList<DalvInsn>(suffixInitialCapacity);
      }
  
      /**
       * Adds an instruction to the output.
       *
       * @param insn {@code non-null;} the instruction to add
       */
      public void add(DalvInsn insn) {
          finisher.add(insn);
      }
  
      /**
       * Reverses a branch which is buried a given number of instructions
       * backward in the output. It is illegal to call this unless the
       * indicated instruction really is a reversible branch.
       *
       * @param which how many instructions back to find the branch;
       * {@code 0} is the most recently added instruction,
       * {@code 1} is the instruction before that, etc.
       * @param newTarget {@code non-null;} the new target for the reversed branch
       */
      public void reverseBranch(int which, CodeAddress newTarget) {
          finisher.reverseBranch(which, newTarget);
      }
  
      /**
       * Adds an instruction to the output suffix.
       *
       * @param insn {@code non-null;} the instruction to add
       */
      public void addSuffix(DalvInsn insn) {
          suffix.add(insn);
      }
  
      /**
       * Gets the results of all the calls on this instance, in the form of
       * an {@link OutputFinisher}.
       *
       * @return {@code non-null;} the output finisher
       * @throws UnsupportedOperationException if this method has
       * already been called
       */
      public OutputFinisher getFinisher() {
          if (suffix == null) {
              throw new UnsupportedOperationException("already processed");
          }
  
          appendSuffixToOutput();
          return finisher;
      }
  
      /**
       * Helper for {@link #getFinisher}, which appends the suffix to
       * the primary output.
       */
      private void appendSuffixToOutput() {
          int size = suffix.size();
  
          for (int i = 0; i < size; i++) {
              finisher.add(suffix.get(i));
          }
  
          suffix = null;
      }
  }
  