2.1/dev/core/src/com/google/gwt/core/linker/SymbolMapsLinker.java

/*
 * Copyright 2009 Google Inc.
 * 
 * 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.google.gwt.core.linker;

import com.google.gwt.core.ext.LinkerContext;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.core.ext.linker.AbstractLinker;
import com.google.gwt.core.ext.linker.ArtifactSet;
import com.google.gwt.core.ext.linker.CompilationResult;
import com.google.gwt.core.ext.linker.EmittedArtifact;
import com.google.gwt.core.ext.linker.LinkerOrder;
import com.google.gwt.core.ext.linker.SelectionProperty;
import com.google.gwt.core.ext.linker.Shardable;
import com.google.gwt.core.ext.linker.SymbolData;
import com.google.gwt.core.ext.linker.LinkerOrder.Order;

import java.io.ByteArrayOutputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.Map;
import java.util.SortedMap;

/**
 * This Linker exports the symbol maps associated with each compilation result
 * as a private file. The names of the symbol maps files are computed by
 * appending {@value #STRONG_NAME_SUFFIX} to the value returned by
 * {@link CompilationResult#getStrongName()}.
 */
@LinkerOrder(Order.POST)
@Shardable
public class SymbolMapsLinker extends AbstractLinker {

  /**
   * This value is appended to the strong name of the CompilationResult to form
   * the symbol map's filename.
   */
  public static final String STRONG_NAME_SUFFIX = ".symbolMap";

  public static String propertyMapToString(
      Map<SelectionProperty, String> propertyMap) {
    StringWriter writer = new StringWriter();
    PrintWriter pw = new PrintWriter(writer);
    printPropertyMap(pw, propertyMap);
    pw.flush();
    return writer.toString();
  }

  private static void printPropertyMap(PrintWriter pw,
      Map<SelectionProperty, String> map) {
    boolean needsComma = false;
    for (Map.Entry<SelectionProperty, String> entry : map.entrySet()) {
      if (needsComma) {
        pw.print(" , ");
      } else {
        needsComma = true;
      }

      pw.print("'");
      pw.print(entry.getKey().getName());
      pw.print("' : '");
      pw.print(entry.getValue());
      pw.print("'");
    }
  }

  @Override
  public String getDescription() {
    return "Export CompilationResult symbol maps";
  }

  /**
   * Included to support legacy non-shardable subclasses.
   */
  @Override
  public ArtifactSet link(TreeLogger logger, LinkerContext context,
      ArtifactSet artifacts) throws UnableToCompleteException {
    return link(logger, context, artifacts, true);
  }

  @Override
  public ArtifactSet link(TreeLogger logger, LinkerContext context,
      ArtifactSet artifacts, boolean onePermutation)
      throws UnableToCompleteException {
    if (onePermutation) {
      artifacts = new ArtifactSet(artifacts);

      ByteArrayOutputStream out = new ByteArrayOutputStream();
      for (CompilationResult result : artifacts.find(CompilationResult.class)) {
        PrintWriter pw = new PrintWriter(out);

        doWriteSymbolMap(logger, result, pw);
        pw.close();

        doEmitSymbolMap(logger, artifacts, result, out);
        out.reset();
      }
    }
    return artifacts;
  }

  /**
   * Override to change the manner in which the symbol map is emitted.
   */
  protected void doEmitSymbolMap(TreeLogger logger, ArtifactSet artifacts,
      CompilationResult result, ByteArrayOutputStream out)
      throws UnableToCompleteException {
    EmittedArtifact symbolMapArtifact = emitBytes(logger, out.toByteArray(),
        result.getStrongName() + STRONG_NAME_SUFFIX);
    symbolMapArtifact.setPrivate(true);
    artifacts.add(symbolMapArtifact);
  }

  /**
   * Override to change the format of the symbol map.
   * 
   * @param logger the logger to write to
   * @param result the compilation result
   * @param pw the output PrintWriter
   *
   * @throws UnableToCompleteException if an error occurs
   */
  protected void doWriteSymbolMap(TreeLogger logger, CompilationResult result,
      PrintWriter pw) throws UnableToCompleteException {
    pw.println("# { " + result.getPermutationId() + " }");

    for (SortedMap<SelectionProperty, String> map : result.getPropertyMap()) {
      pw.print("# { ");
      printPropertyMap(pw, map);
      pw.println(" }");
    }

    pw.println("# jsName, jsniIdent, className, memberName, sourceUri, sourceLine");
    StringBuilder sb = new StringBuilder(1024);
    char[] buf = new char[1024];
    for (SymbolData symbol : result.getSymbolMap()) {
      sb.append(symbol.getSymbolName());

      sb.append(',');
      String jsniIdent = symbol.getJsniIdent();
      if (jsniIdent != null) {
        sb.append(jsniIdent);
      }
      sb.append(',');
      sb.append(symbol.getClassName());
      sb.append(',');
      String memberName = symbol.getMemberName();
      if (memberName != null) {
        sb.append(memberName);
      }
      sb.append(',');
      String sourceUri = symbol.getSourceUri();
      if (sourceUri != null) {
        sb.append(sourceUri);
      }
      sb.append(',');
      sb.append(symbol.getSourceLine());
      sb.append('\n');

      int sbLen = sb.length();
      if (buf.length < sbLen) {
        int bufLen = buf.length;
        while (bufLen < sbLen) {
          bufLen <<= 1;
        }
        buf = new char[bufLen];
      }
      sb.getChars(0, sbLen, buf, 0);
      pw.write(buf, 0, sbLen);
      sb.setLength(0);
    }
  }
}