src/main/java/com/google/devtools/build/lib/packages/StarlarkInfo.java

// Copyright 2023 The Bazel Authors. All rights reserved.
//
// 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.devtools.build.lib.packages;


import java.util.Map;
import javax.annotation.Nullable;
import net.starlark.java.eval.Compactable;
import net.starlark.java.eval.HasBinary;

/** Superclass (provider instance) for providers defined in Starlark. */
public abstract class StarlarkInfo extends StructImpl implements HasBinary, Compactable {
  /**
   * Threshold over which to use binary search for field lookup in lists/arrays.
   *
   * <p>Linear search is faster for small lists/arrays.
   */
  protected static final int BINARY_SEARCH_THRESHOLD = 16;

  /**
   * Creates a schemaless provider instance with the given provider type and field values.
   *
   * @param provider A {@code Provider} without a schema. {@code StarlarkProvider} with a schema is
   *     not supported by this call.
   * @param values the field values
   */
  public static StarlarkInfo create(Provider provider, Map<String, Object> values) {
    return StarlarkInfoNoSchema.createSchemaless(provider, values);
  }

  StarlarkInfo() {}

  // Relax visibility to public. getValue() is widely used to directly access fields from native
  // rule logic. Compared to Starlark.getattr(), it also avoids the need for the caller to pass a
  // Semantics.
  @Nullable
  @Override
  public abstract Object getValue(String name);

  @Override // Tighten return type.
  public abstract StarlarkInfo unsafeOptimizeMemoryLayout();
}