Emulate AbstractManagedChannelImplBuilder maxInboundMessageSize(int)

In dbd903c we started generatating AbstractManagedChannelImplBuilder
methods in a way that they are present for ABI but on recompilation only
public ManagedChannelBuilder-returning methods would be used. However,
this sorta missed maxInboundMessageSize which is now being handled by
the concrete classes (e.g, NettyChannelBuilder) instead of
ManagedChannelImplBuilder. Users on the old ABI will end up getting
ManagedChannelImplBuilder.maxInboundMessageSize() which does nothing.

So, let's just implement the method and have it jump back up to the
concrete class. Hacky, but easy and predictable and will go away once we
remove the rest of the AbstractManagedChannelImplBuilder compatibility
hacks.

Fixes grpc#8313

core/src/main/java/io/grpc/internal/ManagedChannelImplBuilder.java

@@ -707,6 +707,28 @@ int getDefaultPort() {
     return channelBuilderDefaultPortProvider.getDefaultPort();
   }
 
+  // Remove this emulation when we delete AbstractManagedChannelImplBuilder
+  private AbstractManagedChannelImplBuilderEmulator abstractManagedChannelImplBuilderEmulator;
+
+  public interface AbstractManagedChannelImplBuilderEmulator {
+    void maxInboundMessageSize(int max);
+  }
+
+  public void emulateAbstractManagedChannelImplBuilder(
+      AbstractManagedChannelImplBuilderEmulator abstractManagedChannelImplBuilderEmulator) {
+    this.abstractManagedChannelImplBuilderEmulator = abstractManagedChannelImplBuilderEmulator;
+  }
+
+  @Override
+  public ManagedChannelImplBuilder maxInboundMessageSize(int max) {
+    if (abstractManagedChannelImplBuilderEmulator != null) {
+      abstractManagedChannelImplBuilderEmulator.maxInboundMessageSize(max);
+      return this;
+    } else {
+      return super.maxInboundMessageSize(max); // noop
+    }
+  }
+
   private static class DirectAddressNameResolverFactory extends NameResolver.Factory {
     final SocketAddress address;
     final String authority;

netty/src/main/java/io/grpc/netty/NettyChannelBuilder.java

@@ -201,6 +201,7 @@ public int getDefaultPort() {
     managedChannelImplBuilder = new ManagedChannelImplBuilder(target,
         new NettyChannelTransportFactoryBuilder(),
         new NettyChannelDefaultPortProvider());
+    managedChannelImplBuilder.emulateAbstractManagedChannelImplBuilder(new OldBuilderEmulator());
     this.freezeProtocolNegotiatorFactory = false;
   }
 
@@ -211,6 +212,7 @@ public int getDefaultPort() {
         target, channelCreds, callCreds,
         new NettyChannelTransportFactoryBuilder(),
         new NettyChannelDefaultPortProvider());
+    managedChannelImplBuilder.emulateAbstractManagedChannelImplBuilder(new OldBuilderEmulator());
     this.protocolNegotiatorFactory = checkNotNull(negotiator, "negotiator");
     this.freezeProtocolNegotiatorFactory = true;
   }
@@ -221,6 +223,7 @@ public int getDefaultPort() {
         getAuthorityFromAddress(address),
         new NettyChannelTransportFactoryBuilder(),
         new NettyChannelDefaultPortProvider());
+    managedChannelImplBuilder.emulateAbstractManagedChannelImplBuilder(new OldBuilderEmulator());
     this.freezeProtocolNegotiatorFactory = false;
   }
 
@@ -232,6 +235,7 @@ public int getDefaultPort() {
         channelCreds, callCreds,
         new NettyChannelTransportFactoryBuilder(),
         new NettyChannelDefaultPortProvider());
+    managedChannelImplBuilder.emulateAbstractManagedChannelImplBuilder(new OldBuilderEmulator());
     this.protocolNegotiatorFactory = checkNotNull(negotiator, "negotiator");
     this.freezeProtocolNegotiatorFactory = true;
   }
@@ -764,4 +768,11 @@ public void close() {
       groupPool.returnObject(group);
     }
   }
+
+  private final class OldBuilderEmulator implements
+      ManagedChannelImplBuilder.AbstractManagedChannelImplBuilderEmulator {
+    @Override public void maxInboundMessageSize(int max) {
+      NettyChannelBuilder.this.maxInboundMessageSize(max);
+    }
+  }
 }

okhttp/src/main/java/io/grpc/okhttp/OkHttpChannelBuilder.java

@@ -191,6 +191,7 @@ private OkHttpChannelBuilder(String target) {
     managedChannelImplBuilder = new ManagedChannelImplBuilder(target,
         new OkHttpChannelTransportFactoryBuilder(),
         new OkHttpChannelDefaultPortProvider());
+    managedChannelImplBuilder.emulateAbstractManagedChannelImplBuilder(new OldBuilderEmulator());
     this.freezeSecurityConfiguration = false;
   }
 
@@ -201,6 +202,7 @@ private OkHttpChannelBuilder(String target) {
         target, channelCreds, callCreds,
         new OkHttpChannelTransportFactoryBuilder(),
         new OkHttpChannelDefaultPortProvider());
+    managedChannelImplBuilder.emulateAbstractManagedChannelImplBuilder(new OldBuilderEmulator());
     this.sslSocketFactory = factory;
     this.negotiationType = factory == null ? NegotiationType.PLAINTEXT : NegotiationType.TLS;
     this.freezeSecurityConfiguration = true;
@@ -830,4 +832,11 @@ public void close() {
       }
     }
   }
+
+  private final class OldBuilderEmulator implements
+      ManagedChannelImplBuilder.AbstractManagedChannelImplBuilderEmulator {
+    @Override public void maxInboundMessageSize(int max) {
+      OkHttpChannelBuilder.this.maxInboundMessageSize(max);
+    }
+  }
 }