Reduce top-level package dependencies

This commit extracts interfaces for ClientRSocketFactory,
ServerRSocketFactory, and ConnectionSetupPayload, and moves the
implementations into a sub-package with no references to it from the
top-level package.

This removes a large package cycle with io.rsocket at the center
of everything since it currently contains both high level
abstractions that (accessed by everything), as well as core protocol
implementations classes (accessing everything).

The refactoring is functionally neutral and backwards compatible.

Author: rstoyanchev

rsocket-core/src/main/java/io/rsocket/ConnectionSetupPayload.java

@@ -1,159 +1,43 @@
 /*
- * Copyright 2015-2018 the original author or authors.
+ * Copyright 2002-2020 the original author or 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
+ *      https://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.rsocket;
 
 import io.netty.buffer.ByteBuf;
-import io.netty.util.AbstractReferenceCounted;
-import io.rsocket.frame.FrameHeaderFlyweight;
-import io.rsocket.frame.SetupFrameFlyweight;
+import io.netty.util.ReferenceCounted;
 import javax.annotation.Nullable;
 
 /**
- * Exposed to server for determination of ResponderRSocket based on mime types and SETUP
- * metadata/data
+ * Exposes information from the {@code SETUP} frame to a server, as well as to client responders.
  */
-public abstract class ConnectionSetupPayload extends AbstractReferenceCounted implements Payload {
-
-  public static ConnectionSetupPayload create(final ByteBuf setupFrame) {
-    return new DefaultConnectionSetupPayload(setupFrame);
-  }
+public interface ConnectionSetupPayload extends ReferenceCounted, Payload {
 
-  public abstract int keepAliveInterval();
+  String metadataMimeType();
 
-  public abstract int keepAliveMaxLifetime();
+  String dataMimeType();
 
-  public abstract String metadataMimeType();
+  int keepAliveInterval();
 
-  public abstract String dataMimeType();
+  int keepAliveMaxLifetime();
 
-  public abstract int getFlags();
+  int getFlags();
 
-  public abstract boolean willClientHonorLease();
+  boolean willClientHonorLease();
 
-  public abstract boolean isResumeEnabled();
+  boolean isResumeEnabled();
 
   @Nullable
-  public abstract ByteBuf resumeToken();
-
-  @Override
-  public ConnectionSetupPayload retain() {
-    super.retain();
-    return this;
-  }
-
-  @Override
-  public ConnectionSetupPayload retain(int increment) {
-    super.retain(increment);
-    return this;
-  }
-
-  @Override
-  public abstract ConnectionSetupPayload touch();
-
-  @Override
-  public abstract ConnectionSetupPayload touch(Object hint);
-
-  private static final class DefaultConnectionSetupPayload extends ConnectionSetupPayload {
-    private final ByteBuf setupFrame;
-
-    public DefaultConnectionSetupPayload(ByteBuf setupFrame) {
-      this.setupFrame = setupFrame;
-    }
-
-    @Override
-    public boolean hasMetadata() {
-      return FrameHeaderFlyweight.hasMetadata(setupFrame);
-    }
-
-    @Override
-    public int keepAliveInterval() {
-      return SetupFrameFlyweight.keepAliveInterval(setupFrame);
-    }
-
-    @Override
-    public int keepAliveMaxLifetime() {
-      return SetupFrameFlyweight.keepAliveMaxLifetime(setupFrame);
-    }
-
-    @Override
-    public String metadataMimeType() {
-      return SetupFrameFlyweight.metadataMimeType(setupFrame);
-    }
-
-    @Override
-    public String dataMimeType() {
-      return SetupFrameFlyweight.dataMimeType(setupFrame);
-    }
-
-    @Override
-    public int getFlags() {
-      return FrameHeaderFlyweight.flags(setupFrame);
-    }
-
-    @Override
-    public boolean willClientHonorLease() {
-      return SetupFrameFlyweight.honorLease(setupFrame);
-    }
-
-    @Override
-    public boolean isResumeEnabled() {
-      return SetupFrameFlyweight.resumeEnabled(setupFrame);
-    }
-
-    @Override
-    public ByteBuf resumeToken() {
-      return SetupFrameFlyweight.resumeToken(setupFrame);
-    }
-
-    @Override
-    public ConnectionSetupPayload touch() {
-      setupFrame.touch();
-      return this;
-    }
-
-    @Override
-    public ConnectionSetupPayload touch(Object hint) {
-      setupFrame.touch(hint);
-      return this;
-    }
-
-    @Override
-    protected void deallocate() {
-      setupFrame.release();
-    }
-
-    @Override
-    public ByteBuf sliceMetadata() {
-      return SetupFrameFlyweight.metadata(setupFrame);
-    }
-
-    @Override
-    public ByteBuf sliceData() {
-      return SetupFrameFlyweight.data(setupFrame);
-    }
-
-    @Override
-    public ByteBuf data() {
-      return sliceData();
-    }
-
-    @Override
-    public ByteBuf metadata() {
-      return sliceMetadata();
-    }
-  }
+  ByteBuf resumeToken();
 }