dx/src/com/android/jack/dx/dex/file/MethodIdsSection.java

/*
 * 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.android.jack.dx.dex.file;

import com.android.jack.dx.rop.cst.Constant;
import com.android.jack.dx.rop.cst.CstBaseMethodRef;
import com.android.jack.dx.util.AnnotatedOutput;
import com.android.jack.dx.util.Hex;

import java.util.Collection;
import java.util.TreeMap;

/**
 * Method refs list section of a {@code .dex} file.
 */
public final class MethodIdsSection extends MemberIdsSection {
  /**
   * {@code non-null;} map from method constants to {@link
   * MethodIdItem} instances
   */
  private final TreeMap<CstBaseMethodRef, MethodIdItem> methodIds;

  /**
   * Constructs an instance. The file offset is initially unknown.
   *
   * @param file {@code non-null;} file that this instance is part of
   */
  public MethodIdsSection(DexFile file) {
    super("method_ids", file);

    methodIds = new TreeMap<CstBaseMethodRef, MethodIdItem>();
  }

  /** {@inheritDoc} */
  @Override
  public Collection<? extends Item> items() {
    return methodIds.values();
  }

  /** {@inheritDoc} */
  @Override
  public IndexedItem get(Constant cst) {
    if (cst == null) {
      throw new NullPointerException("cst == null");
    }

    throwIfNotPrepared();

    IndexedItem result = methodIds.get(cst);

    if (result == null) {
      throw new IllegalArgumentException("not found");
    }

    return result;
  }

  /**
   * Writes the portion of the file header that refers to this instance.
   *
   * @param out {@code non-null;} where to write
   */
  public void writeHeaderPart(AnnotatedOutput out) {
    throwIfNotPrepared();

    int sz = methodIds.size();
    int offset = (sz == 0) ? 0 : getFileOffset();

    if (out.annotates()) {
      out.annotate(4, "method_ids_size: " + Hex.u4(sz));
      out.annotate(4, "method_ids_off:  " + Hex.u4(offset));
    }

    out.writeInt(sz);
    out.writeInt(offset);
  }

  /**
   * Interns an element into this instance.
   *
   * @param method {@code non-null;} the reference to intern
   * @return {@code non-null;} the interned reference
   */
  public MethodIdItem intern(CstBaseMethodRef method) {
    if (method == null) {
      throw new NullPointerException("method == null");
    }

    throwIfPrepared();

    MethodIdItem result = methodIds.get(method);

    if (result == null) {
      result = new MethodIdItem(method);
      methodIds.put(method, result);
    }

    return result;
  }

  /**
   * Gets the index of the given reference, which must have been added
   * to this instance.
   *
   * @param ref {@code non-null;} the reference to look up
   * @return {@code >= 0;} the reference's index
   */
  public int indexOf(CstBaseMethodRef ref) {
    if (ref == null) {
      throw new NullPointerException("ref == null");
    }

    throwIfNotPrepared();

    MethodIdItem item = methodIds.get(ref);

    if (item == null) {
      throw new IllegalArgumentException("not found");
    }

    return item.getIndex();
  }
}