core: add CallCredentials2 and deprecate CallCredentials' old interface (#4902)

This is the first step of smoothly changing the CallCredentials API.

Security level and authority are parameters required to be passed to
applyRequestMetadata(). This change wraps them, along with
MethodDescriptor and the transport attributes to RequestInfo, which is
more clear to the implementers.

ATTR_SECURITY_LEVEL is moved to the internal GrpcAttributes and
annotated as TransportAttr, because transports are required to set it,
but no user is actually reading them from
{Client,Server}Call.getAttributes().

ATTR_AUTHORITY is removed, because no transport is overriding it.

All involved interfaces are changed to abstract classes, as this will
make further API changes smoother.

The CallCredentials name is stabilized, thus we first introduce
CallCredentials2, ask CallCredentials implementations to migrate to
it, while GRPC accepting both at the same time, then replace
CallCredentials with CallCredentials2.

1 files changed, 4 insertions, 4 deletions

diff --git a/netty/src/main/java/io/grpc/netty/ProtocolNegotiators.java b/netty/src/main/java/io/grpc/netty/ProtocolNegotiators.java
index 684a67f3e..061801705 100644
--- a/netty/src/main/java/io/grpc/netty/ProtocolNegotiators.java
+++ b/netty/src/main/java/io/grpc/netty/ProtocolNegotiators.java
@@ -22,12 +22,12 @@ import static io.grpc.netty.GrpcSslContexts.NEXT_PROTOCOL_VERSIONS;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import io.grpc.Attributes;
-import io.grpc.CallCredentials;
 import io.grpc.Grpc;
 import io.grpc.Internal;
 import io.grpc.InternalChannelz;
 import io.grpc.SecurityLevel;
 import io.grpc.Status;
+import io.grpc.internal.GrpcAttributes;
 import io.grpc.internal.GrpcUtil;
 import io.netty.channel.ChannelDuplexHandler;
 import io.netty.channel.ChannelFuture;
@@ -676,7 +676,7 @@ public final class ProtocolNegotiators {
                     .set(Grpc.TRANSPORT_ATTR_SSL_SESSION, session)
                     .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, ctx.channel().remoteAddress())
                     .set(Grpc.TRANSPORT_ATTR_LOCAL_ADDR, ctx.channel().localAddress())
-                    .set(CallCredentials.ATTR_SECURITY_LEVEL, SecurityLevel.PRIVACY_AND_INTEGRITY)
+                    .set(GrpcAttributes.ATTR_SECURITY_LEVEL, SecurityLevel.PRIVACY_AND_INTEGRITY)
                     .build(),
                 new InternalChannelz.Security(new InternalChannelz.Tls(session)));
             writeBufferedAndRemove(ctx);
@@ -725,7 +725,7 @@ public final class ProtocolNegotiators {
               .newBuilder()
               .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, ctx.channel().remoteAddress())
               .set(Grpc.TRANSPORT_ATTR_LOCAL_ADDR, ctx.channel().localAddress())
-              .set(CallCredentials.ATTR_SECURITY_LEVEL, SecurityLevel.NONE)
+              .set(GrpcAttributes.ATTR_SECURITY_LEVEL, SecurityLevel.NONE)
               .build(),
           /*securityInfo=*/ null);
       super.channelActive(ctx);
@@ -769,7 +769,7 @@ public final class ProtocolNegotiators {
                 .newBuilder()
                 .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, ctx.channel().remoteAddress())
                 .set(Grpc.TRANSPORT_ATTR_LOCAL_ADDR, ctx.channel().localAddress())
-                .set(CallCredentials.ATTR_SECURITY_LEVEL, SecurityLevel.NONE)
+                .set(GrpcAttributes.ATTR_SECURITY_LEVEL, SecurityLevel.NONE)
                 .build(),
             /*securityInfo=*/ null);
       } else if (evt == HttpClientUpgradeHandler.UpgradeEvent.UPGRADE_REJECTED) {