io.grpc.InternalMetadata Maven / Gradle / Ivy
/*
* Copyright 2016 The gRPC Authors
*
* 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 io.grpc;
import com.google.common.io.BaseEncoding;
import io.grpc.Metadata.AsciiMarshaller;
import io.grpc.Metadata.BinaryStreamMarshaller;
import java.io.InputStream;
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.
*
* Extended here to break the dependency.
*/
@Internal
public interface TrustedAsciiMarshaller extends Metadata.TrustedAsciiMarshaller {}
/**
* Copy of StandardCharsets, which is only available on Java 1.7 and above.
*/
@Internal
public static final Charset US_ASCII = Charset.forName("US-ASCII");
/**
* An instance of base64 encoder that omits padding.
*/
@Internal
public static final BaseEncoding BASE64_ENCODING_OMIT_PADDING
= Metadata.BASE64_ENCODING_OMIT_PADDING;
@Internal
public static Metadata.Key keyOf(String name, TrustedAsciiMarshaller marshaller) {
boolean isPseudo = name != null && !name.isEmpty() && name.charAt(0) == ':';
return Metadata.Key.of(name, isPseudo, marshaller);
}
@Internal
public static Metadata.Key keyOf(String name, AsciiMarshaller marshaller) {
boolean isPseudo = name != null && !name.isEmpty() && name.charAt(0) == ':';
return Metadata.Key.of(name, isPseudo, 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();
}
@Internal
public static int headerCount(Metadata md) {
return md.headerCount();
}
/**
* Serializes all metadata entries, leaving some values as {@link InputStream}s.
*
* Produces serialized names and values interleaved. result[i*2] are names, while
* result[i*2+1] are values.
*
*
Names are byte arrays as described according to the {@link Metadata#serialize}
* method. Values are either byte arrays or {@link InputStream}s.
*/
@Internal
public static Object[] serializePartial(Metadata md) {
return md.serializePartial();
}
/**
* Creates a holder for a pre-parsed value read by the transport.
*
* @param marshaller The {@link Metadata.BinaryStreamMarshaller} associated with this value.
* @param value The value to store.
* @return an object holding the pre-parsed value for this key.
*/
@Internal
public static Object parsedValue(BinaryStreamMarshaller marshaller, T value) {
return new Metadata.LazyValue<>(marshaller, value);
}
/**
* Creates a new {@link Metadata} instance from serialized data,
* with some values pre-parsed. Metadata will mutate the passed in array.
*
* @param usedNames The number of names used.
* @param namesAndValues An array of interleaved names and values,
* with each name (at even indices) represented as a byte array,
* and each value (at odd indices) represented as either a byte
* array or an object returned by the {@link #parsedValue}
* method.
*/
@Internal
public static Metadata newMetadataWithParsedValues(int usedNames, Object[] namesAndValues) {
return new Metadata(usedNames, namesAndValues);
}
}