core/src/main/java/io/grpc/InternalMetadata.java

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package io.grpc;

import io.grpc.Metadata.Key;

import java.nio.charset.Charset;

/**
 * Internal {@link Metadata} accessor. This is intended for use by io.grpc.internal, and the
 * specifically supported transport packages. If you *really* think you need to use this, contact
 * the gRPC team first.
 */
@Internal
public final class InternalMetadata {

  /**
   * A specialized plain ASCII marshaller. Both input and output are assumed to be valid header
   * ASCII.
   *
   * <p>Extended here to break the dependency.
   */
  @Internal
  public interface TrustedAsciiMarshaller<T> extends Metadata.TrustedAsciiMarshaller<T> {}

  /**
   * Copy of StandardCharsets, which is only available on Java 1.7 and above.
   */
  @Internal
  public static final Charset US_ASCII = Charset.forName("US-ASCII");

  @Internal
  public static <T> Key<T> keyOf(String name, TrustedAsciiMarshaller<T> marshaller) {
    return Metadata.Key.of(name, marshaller);
  }

  @Internal
  public static Metadata newMetadata(byte[]... binaryValues) {
    return new Metadata(binaryValues);
  }

  @Internal
  public static Metadata newMetadata(int usedNames, byte[]... binaryValues) {
    return new Metadata(usedNames, binaryValues);
  }

  @Internal
  public static byte[][] serialize(Metadata md) {
    return md.serialize();
  }
}