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

/*
 * Copyright (C) 2008 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.CstPrototypeRef;
import com.android.jack.dx.rop.type.Prototype;
import com.android.jack.dx.util.AnnotatedOutput;
import com.android.jack.dx.util.Hex;

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

import javax.annotation.Nonnull;

/**
 * Proto (method prototype) identifiers list section of a
 * {@code .dex} file.
 */
public final class ProtoIdsSection extends UniformItemSection {
  /**
   * {@code non-null;} map from method prototypes to {@link ProtoIdItem} instances
   */
  private final TreeMap<Prototype, ProtoIdItem> protoIds;

  /**
   * Constructs an instance. The file offset is initially unknown.
   *
   * @param file {@code non-null;} file that this instance is part of
   */
  public ProtoIdsSection(DexFile file) {
    super("proto_ids", file, 4);

    protoIds = new TreeMap<Prototype, ProtoIdItem>();
  }

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

  /** {@inheritDoc} */
  @Override
  @Nonnull
  public IndexedItem get(@Nonnull Constant cst) {
    throwIfNotPrepared();

    IndexedItem result = protoIds.get(((CstPrototypeRef) cst).getPrototype());
    assert result != null;

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

    if (sz > 65536) {
      throw new UnsupportedOperationException("too many proto ids");
    }

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

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

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

    throwIfPrepared();

    ProtoIdItem result = protoIds.get(prototype);

    if (result == null) {
      result = new ProtoIdItem(prototype);
      protoIds.put(prototype, result);
    }

    return result;
  }

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

    throwIfNotPrepared();

    ProtoIdItem item = protoIds.get(prototype);

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

    return item.getIndex();
  }

  /** {@inheritDoc} */
  @Override
  protected void orderItems() {
    int idx = 0;

    for (Object i : items()) {
      ((ProtoIdItem) i).setIndex(idx);
      idx++;
    }
  }
}