com.google.eclipse.protobuf/src/com/google/eclipse/protobuf/scoping/Globals.java

/*
 * Copyright (c) 2011 Google Inc.
 *
 * 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
 */
package com.google.eclipse.protobuf.scoping;

import static java.util.Collections.unmodifiableCollection;
import static org.eclipse.core.runtime.FileLocator.*;

import java.io.*;
import java.net.URL;
import java.util.*;

import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.Platform;
import org.eclipse.emf.common.util.URI;
import org.eclipse.xtext.parser.IParseResult;
import org.eclipse.xtext.parser.IParser;
import org.eclipse.xtext.resource.XtextResource;
import org.osgi.framework.Bundle;

import com.google.eclipse.protobuf.protobuf.*;
import com.google.eclipse.protobuf.protobuf.Enum;
import com.google.eclipse.protobuf.util.EObjectFinder;
import com.google.inject.Inject;
import com.google.inject.Singleton;

/**
 * Protobuf elements accesible to any .proto file.
 *
 * @author alruiz@google.com (Alex Ruiz)
 */
@Singleton
public class Globals {

  private Protobuf root;

  private boolean initialized;
  private Map<String, Property> fileOptions = new LinkedHashMap<String, Property>();
  private Enum optimizedMode;

  @Inject EObjectFinder finder;

  @Inject public Globals(IParser parser) {
    try {
      XtextResource resource = new XtextResource(URI.createURI(""));
      IParseResult result = parser.parse(new InputStreamReader(globalScopeContents(), "UTF-8"));
      root = (Protobuf) result.getRootASTElement();
      resource.getContents().add(root);
    } catch (IOException e) {
      throw new IllegalStateException("Unable to parse global scope", e);
    }
  }

  private static InputStream globalScopeContents() throws IOException {
    Bundle bundle = Platform.getBundle("com.google.eclipse.protobuf");
    Path originPath = new Path("global.proto");
    URL bundledFileURL = find(bundle, originPath, null);
    return (InputStream) resolve(bundledFileURL).getContent();
  }

  private void init() {
    if (initialized) return;
    initialized = true;
    Message m = fileOptionsMessage();
    for (MessageElement e : m.getElements()) {
      if (e instanceof Property) {
        addFileOption((Property) e);
        continue;
      }
      if (e instanceof Enum && "OptimizeMode".equals(e.getName())) {
        optimizedMode = (Enum) e;
        continue;
      }
    }
  }

  private Message fileOptionsMessage() {
    for (ProtobufElement e : root.getElements()) {
      if (!(e instanceof Message)) continue;
      Message m = (Message) e;
      if ("FileOptions".equals(m.getName())) return m;
    }
    return null;
  }

  private void addFileOption(Property p) {
    fileOptions.put(p.getName(), p);
  }

  public Collection<Property> fileOptions() {
    init();
    return unmodifiableCollection(fileOptions.values());
  }

  public Enum optimizedMode() {
    init();
    return optimizedMode;
  }

  public boolean isOptimizeForOption(Option option) {
    init();
    return "optimize_for".equals(option.getName());
  }

  public Property lookupFileOption(String name) {
    init();
    return fileOptions.get(name);
  }
}