HADOOP-16621. [pb-upgrade] Remove Protobuf classes from signatures of Public APIs. Fixed Review comments

Author: vinayakumarb

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ipc/ProtobufHelper.java

@@ -22,7 +22,7 @@
 
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.io.Text;
-import org.apache.hadoop.security.proto.SecurityProtos;
+import org.apache.hadoop.security.proto.SecurityProtos.TokenProto;
 import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.security.token.TokenIdentifier;
 
@@ -62,8 +62,8 @@ public static IOException getRemoteException(ServiceException se) {
    * This map should not be accessed directly. Used the getFixedByteString
    * methods instead.
    */
-  private static ConcurrentHashMap<Object, ByteString> fixedByteStringCache =
-      new ConcurrentHashMap<>();
+  private final static ConcurrentHashMap<Object, ByteString>
+      fixedByteStringCache = new ConcurrentHashMap<>();
 
   /**
    * Get the ByteString for frequently used fixed and small set strings.
@@ -98,17 +98,17 @@ public static ByteString getByteString(byte[] bytes) {
     return (bytes.length == 0) ? ByteString.EMPTY : ByteString.copyFrom(bytes);
   }
 
-  public static Token<? extends TokenIdentifier> convert(
-      SecurityProtos.TokenProto tokenProto) {
+  public static Token<? extends TokenIdentifier> tokenFromProto(
+      TokenProto tokenProto) {
     Token<? extends TokenIdentifier> token = new Token<>(
         tokenProto.getIdentifier().toByteArray(),
         tokenProto.getPassword().toByteArray(), new Text(tokenProto.getKind()),
         new Text(tokenProto.getService()));
     return token;
   }
 
-  public static SecurityProtos.TokenProto convert(Token<?> tok) {
-    SecurityProtos.TokenProto.Builder builder = SecurityProtos.TokenProto.newBuilder().
+  public static TokenProto protoFromToken(Token<?> tok) {
+    TokenProto.Builder builder = TokenProto.newBuilder().
         setIdentifier(getByteString(tok.getIdentifier())).
         setPassword(getByteString(tok.getPassword())).
         setKindBytes(getFixedByteString(tok.getKind())).

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/Credentials.java

@@ -369,7 +369,7 @@ void writeProto(DataOutput out) throws IOException {
       CredentialsKVProto.Builder kv = CredentialsKVProto.newBuilder().
           setAliasBytes(ByteString.copyFrom(
               e.getKey().getBytes(), 0, e.getKey().getLength())).
-          setToken(ProtobufHelper.convert(e.getValue()));
+          setToken(ProtobufHelper.protoFromToken(e.getValue()));
       storage.addTokens(kv.build());
     }
 
@@ -391,7 +391,7 @@ void readProto(DataInput in) throws IOException {
     CredentialsProto storage = CredentialsProto.parseDelimitedFrom((DataInputStream)in);
     for (CredentialsKVProto kv : storage.getTokensList()) {
       addToken(new Text(kv.getAliasBytes().toByteArray()),
-               ProtobufHelper.convert(kv.getToken()));
+               ProtobufHelper.tokenFromProto(kv.getToken()));
     }
     for (CredentialsKVProto kv : storage.getSecretsList()) {
       addSecretKey(new Text(kv.getAliasBytes().toByteArray()),

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelperClient.java

@@ -324,7 +324,7 @@ public static ExtendedBlockProto convert(final ExtendedBlock b) {
   }
 
   public static TokenProto convert(Token<?> tok) {
-    return ProtobufHelper.convert(tok);
+    return ProtobufHelper.protoFromToken(tok);
   }
 
   public static ShortCircuitShmIdProto convert(ShmId shmId) {
@@ -802,7 +802,8 @@ public static StorageType[] convertStorageTypes(
 
   public static Token<BlockTokenIdentifier> convert(
       TokenProto blockToken) {
-    return (Token<BlockTokenIdentifier>) ProtobufHelper.convert(blockToken);
+    return (Token<BlockTokenIdentifier>) ProtobufHelper
+        .tokenFromProto(blockToken);
   }
 
   // DatanodeId