FieldMaskUtil.java

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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// https://developers.google.com/protocol-buffers/
//
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// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
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package com.google.protobuf.util;
 
import static com.google.common.base.Preconditions.checkArgument;
 
import com.google.common.base.CaseFormat;
import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.primitives.Ints;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.protobuf.Descriptors.Descriptor;
import com.google.protobuf.Descriptors.FieldDescriptor;
import com.google.protobuf.FieldMask;
import com.google.protobuf.Internal;
import com.google.protobuf.Message;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
 
public class FieldMaskUtil {
  private static final String FIELD_PATH_SEPARATOR = ",";
  private static final String FIELD_PATH_SEPARATOR_REGEX = ",";
  private static final String FIELD_SEPARATOR_REGEX = "\\.";
 
  private FieldMaskUtil() {}
 
  public static String toString(FieldMask fieldMask) {
    // TODO(xiaofeng): Consider using com.google.common.base.Joiner here instead.
    StringBuilder result = new StringBuilder();
    boolean first = true;
    for (String value : fieldMask.getPathsList()) {
      if (value.isEmpty()) {
        // Ignore empty paths.
        continue;
      }
      if (first) {
        first = false;
      } else {
        result.append(FIELD_PATH_SEPARATOR);
      }
      result.append(value);
    }
    return result.toString();
  }
 
  public static FieldMask fromString(String value) {
    // TODO(xiaofeng): Consider using com.google.common.base.Splitter here instead.
    return fromStringList(null, Arrays.asList(value.split(FIELD_PATH_SEPARATOR_REGEX)));
  }
 
  public static FieldMask fromString(Class<? extends Message> type, String value) {
    // TODO(xiaofeng): Consider using com.google.common.base.Splitter here instead.
    return fromStringList(type, Arrays.asList(value.split(FIELD_PATH_SEPARATOR_REGEX)));
  }
 
  // TODO(xiaofeng): Consider renaming fromStrings()
  public static FieldMask fromStringList(Class<? extends Message> type, Iterable<String> paths) {
    FieldMask.Builder builder = FieldMask.newBuilder();
    for (String path : paths) {
      if (path.isEmpty()) {
        // Ignore empty field paths.
        continue;
      }
      if (type != null && !isValid(type, path)) {
        throw new IllegalArgumentException(path + " is not a valid path for " + type);
      }
      builder.addPaths(path);
    }
    return builder.build();
  }
 
  public static FieldMask fromFieldNumbers(Class<? extends Message> type, int... fieldNumbers) {
    return fromFieldNumbers(type, Ints.asList(fieldNumbers));
  }
 
  public static FieldMask fromFieldNumbers(
      Class<? extends Message> type, Iterable<Integer> fieldNumbers) {
    Descriptor descriptor = Internal.getDefaultInstance(type).getDescriptorForType();
 
    FieldMask.Builder builder = FieldMask.newBuilder();
    for (Integer fieldNumber : fieldNumbers) {
      FieldDescriptor field = descriptor.findFieldByNumber(fieldNumber);
      checkArgument(
          field != null,
          String.format("%s is not a valid field number for %s.", fieldNumber, type));
      builder.addPaths(field.getName());
    }
    return builder.build();
  }
 
  public static String toJsonString(FieldMask fieldMask) {
    List<String> paths = new ArrayList<String>(fieldMask.getPathsCount());
    for (String path : fieldMask.getPathsList()) {
      if (path.isEmpty()) {
        continue;
      }
      paths.add(CaseFormat.LOWER_UNDERSCORE.to(CaseFormat.LOWER_CAMEL, path));
    }
    return Joiner.on(FIELD_PATH_SEPARATOR).join(paths);
  }
 
  public static FieldMask fromJsonString(String value) {
    Iterable<String> paths = Splitter.on(FIELD_PATH_SEPARATOR).split(value);
    FieldMask.Builder builder = FieldMask.newBuilder();
    for (String path : paths) {
      if (path.isEmpty()) {
        continue;
      }
      builder.addPaths(CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_UNDERSCORE, path));
    }
    return builder.build();
  }
 
  public static boolean isValid(Class<? extends Message> type, FieldMask fieldMask) {
    Descriptor descriptor = Internal.getDefaultInstance(type).getDescriptorForType();
 
    return isValid(descriptor, fieldMask);
  }
 
  public static boolean isValid(Descriptor descriptor, FieldMask fieldMask) {
    for (String path : fieldMask.getPathsList()) {
      if (!isValid(descriptor, path)) {
        return false;
      }
    }
    return true;
  }
 
  public static boolean isValid(Class<? extends Message> type, String path) {
    Descriptor descriptor = Internal.getDefaultInstance(type).getDescriptorForType();
 
    return isValid(descriptor, path);
  }
 
  public static boolean isValid(Descriptor descriptor, String path) {
    String[] parts = path.split(FIELD_SEPARATOR_REGEX);
    if (parts.length == 0) {
      return false;
    }
    for (String name : parts) {
      if (descriptor == null) {
        return false;
      }
      FieldDescriptor field = descriptor.findFieldByName(name);
      if (field == null) {
        return false;
      }
      if (!field.isRepeated() && field.getJavaType() == FieldDescriptor.JavaType.MESSAGE) {
        descriptor = field.getMessageType();
      } else {
        descriptor = null;
      }
    }
    return true;
  }
 
  public static FieldMask normalize(FieldMask mask) {
    return new FieldMaskTree(mask).toFieldMask();
  }
 
  public static FieldMask union(
      FieldMask firstMask, FieldMask secondMask, FieldMask... otherMasks) {
    FieldMaskTree maskTree = new FieldMaskTree(firstMask).mergeFromFieldMask(secondMask);
    for (FieldMask mask : otherMasks) {
      maskTree.mergeFromFieldMask(mask);
    }
    return maskTree.toFieldMask();
  }
 
  public static FieldMask intersection(FieldMask mask1, FieldMask mask2) {
    FieldMaskTree tree = new FieldMaskTree(mask1);
    FieldMaskTree result = new FieldMaskTree();
    for (String path : mask2.getPathsList()) {
      tree.intersectFieldPath(path, result);
    }
    return result.toFieldMask();
  }
 
  public static final class MergeOptions {
    private boolean replaceMessageFields = false;
    private boolean replaceRepeatedFields = false;
    // TODO(b/28277137): change the default behavior to always replace primitive fields after
    // fixing all failing TAP tests.
    private boolean replacePrimitiveFields = false;
 
    public boolean replaceMessageFields() {
      return replaceMessageFields;
    }
 
    public boolean replaceRepeatedFields() {
      return replaceRepeatedFields;
    }
 
    public boolean replacePrimitiveFields() {
      return replacePrimitiveFields;
    }
 
    @CanIgnoreReturnValue
    public MergeOptions setReplaceMessageFields(boolean value) {
      replaceMessageFields = value;
      return this;
    }
 
    @CanIgnoreReturnValue
    public MergeOptions setReplaceRepeatedFields(boolean value) {
      replaceRepeatedFields = value;
      return this;
    }
 
    @CanIgnoreReturnValue
    public MergeOptions setReplacePrimitiveFields(boolean value) {
      replacePrimitiveFields = value;
      return this;
    }
  }
 
  public static void merge(
      FieldMask mask, Message source, Message.Builder destination, MergeOptions options) {
    new FieldMaskTree(mask).merge(source, destination, options);
  }
 
  public static void merge(FieldMask mask, Message source, Message.Builder destination) {
    merge(mask, source, destination, new MergeOptions());
  }
}