org.apache.hadoop.ipc.internal.ShadedProtobufHelper Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.hadoop.ipc.internal;
import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.security.proto.SecurityProtos.TokenProto;
import org.apache.hadoop.security.token.Token;
import org.apache.hadoop.security.token.TokenIdentifier;
import org.apache.hadoop.thirdparty.protobuf.ByteString;
import org.apache.hadoop.thirdparty.protobuf.ServiceException;
/**
* Helper methods for protobuf related RPC implementation using the
* hadoop {@code org.apache.hadoop.thirdparty.protobuf} shaded version.
* This is absolutely private to hadoop-* modules.
*/
@InterfaceAudience.Private
@InterfaceStability.Unstable
public final class ShadedProtobufHelper {
private ShadedProtobufHelper() {
// Hidden constructor for class with only static helper methods
}
/**
* Return the IOException thrown by the remote server wrapped in
* ServiceException as cause.
* The signature of this method changes with updates to the hadoop-thirdparty
* shaded protobuf library.
* @param se ServiceException that wraps IO exception thrown by the server
* @return Exception wrapped in ServiceException or
* a new IOException that wraps the unexpected ServiceException.
*/
@InterfaceAudience.Private
@InterfaceStability.Unstable
public static IOException getRemoteException(ServiceException se) {
Throwable e = se.getCause();
if (e == null) {
return new IOException(se);
}
return e instanceof IOException
? (IOException) e
: new IOException(se);
}
/**
* Map used to cache fixed strings to ByteStrings. Since there is no
* automatic expiration policy, only use this for strings from a fixed, small
* set.
*
* This map should not be accessed directly. Used the getFixedByteString
* methods instead.
*/
private static final ConcurrentHashMap
FIXED_BYTESTRING_CACHE = new ConcurrentHashMap<>();
/**
* Get the ByteString for frequently used fixed and small set strings.
* @param key Hadoop Writable Text string
* @return the ByteString for frequently used fixed and small set strings.
*/
public static ByteString getFixedByteString(Text key) {
ByteString value = FIXED_BYTESTRING_CACHE.get(key);
if (value == null) {
value = ByteString.copyFromUtf8(key.toString());
FIXED_BYTESTRING_CACHE.put(new Text(key.copyBytes()), value);
}
return value;
}
/**
* Get the ByteString for frequently used fixed and small set strings.
* @param key string
* @return ByteString for frequently used fixed and small set strings.
*/
public static ByteString getFixedByteString(String key) {
ByteString value = FIXED_BYTESTRING_CACHE.get(key);
if (value == null) {
value = ByteString.copyFromUtf8(key);
FIXED_BYTESTRING_CACHE.put(key, value);
}
return value;
}
/**
* Get the byte string of a non-null byte array.
* If the array is 0 bytes long, return a singleton to reduce object allocation.
* @param bytes bytes to convert.
* @return the protobuf byte string representation of the array.
*/
public static ByteString getByteString(byte[] bytes) {
// return singleton to reduce object allocation
return (bytes.length == 0)
? ByteString.EMPTY
: ByteString.copyFrom(bytes);
}
/**
* Create a hadoop token from a protobuf token.
* @param tokenProto token
* @return a new token
*/
public static Token tokenFromProto(
TokenProto tokenProto) {
Token token = new Token<>(
tokenProto.getIdentifier().toByteArray(),
tokenProto.getPassword().toByteArray(),
new Text(tokenProto.getKind()),
new Text(tokenProto.getService()));
return token;
}
/**
* Create a {@code TokenProto} instance
* from a hadoop token.
* This builds and caches the fields
* (identifier, password, kind, service) but not
* renewer or any payload.
* @param tok token
* @return a marshallable protobuf class.
*/
public static TokenProto protoFromToken(Token tok) {
TokenProto.Builder builder = TokenProto.newBuilder().
setIdentifier(getByteString(tok.getIdentifier())).
setPassword(getByteString(tok.getPassword())).
setKindBytes(getFixedByteString(tok.getKind())).
setServiceBytes(getFixedByteString(tok.getService()));
return builder.build();
}
/**
* Evaluate a protobuf call, converting any ServiceException to an IOException.
* @param call invocation to make
* @return the result of the call
* @param type of the result
* @throws IOException any translated protobuf exception
*/
public static T ipc(IpcCall call) throws IOException {
try {
return call.call();
} catch (ServiceException e) {
throw getRemoteException(e);
}
}
@FunctionalInterface
public interface IpcCall {
T call() throws ServiceException;
}
}