implement streaming requests

compiler/src/main/cpp/capnpc-java.c++

@@ -2027,9 +2027,6 @@ private:
         kj::strTree(
           sp, "  public static final class ", methodName, " {\n",
           sp, "    public interface Request extends org.capnproto.Request<", paramBuilder, "> {\n",
-          sp, "      default org.capnproto.FromPointerBuilder<", paramBuilder, "> getParamsFactory() {\n",
-          sp, "        return ", paramFactory, ";\n",
-          sp, "      }\n",
           sp, "      default Response send() {\n",
           sp, "        return new Response(this.sendInternal());\n",
           sp, "      }\n",
@@ -2050,7 +2047,7 @@ private:
         // client call
         kj::strTree(
           sp, "public Methods.", methodName, ".Request ", methodName, "Request() {\n",
-          sp, "  var result = newCall(0x", interfaceIdHex, "L, (short)", methodId, ");\n",
+          sp, "  var result = newCall(", paramFactory, ", 0x", interfaceIdHex, "L, (short)", methodId, ");\n",
           sp, "  return () -> result;\n",
           sp, "}\n"
         ),

runtime-rpc/src/main/java/org/capnproto/RpcState.java

@@ -1698,9 +1698,9 @@ final class RpcState<VatId> {
         }
 
         @Override
-        public CompletionStage<?> sendStreaming() {
+        public CompletableFuture<java.lang.Void> sendStreaming() {
             // TODO falling back to regular send for now...
-            return send();
+            return send().thenApply(results -> null);
         }
 
         QuestionRef sendInternal(boolean isTailCall) {

runtime-rpc/src/test/java/org/capnproto/CapabilityTest.java

@@ -215,8 +215,6 @@ public final class CapabilityTest {
         var factory = Test.TestGenerics.newFactory(Test.TestAllTypes.factory, AnyPointer.factory);
     }
 
-
-
     @org.junit.Test
     public void thisCap() {
         var callCount = new Counter();
@@ -234,4 +232,16 @@ public final class CapabilityTest {
         client2.barRequest().send().join();
         Assert.assertEquals(3, callCount.value());
     }
+
+    @org.junit.Test
+    public void testStreamingCallsBlockSubsequentCalls() {
+        var server = new RpcTestUtil.TestStreamingImpl();
+        var cap = new Test.TestStreaming.Client(server);
+
+        {
+            var req = cap.doStreamIRequest();
+        }
+
+
+    }
 }

runtime-rpc/src/test/java/org/capnproto/RpcTestUtil.java

@@ -230,6 +230,7 @@ class RpcTestUtil {
         public TestTailCalleeImpl(Counter count) {
             this(count, READY_NOW);
         }
+
         public TestTailCalleeImpl(Counter count, CompletableFuture<java.lang.Void> releaseMe) {
             this.count = count;
             this.releaseMe = releaseMe;
@@ -328,5 +329,40 @@ class RpcTestUtil {
             return this.impl.foo(context);
         }
     }
+
+    static class TestStreamingImpl
+        extends Test.TestStreaming.Server {
+
+        public int iSum = 0;
+        public int jSum = 0;
+        CompletableFuture<java.lang.Void> fulfiller;
+        boolean jShouldThrow = false;
+
+        @Override
+        protected CompletableFuture<java.lang.Void> doStreamI(StreamingCallContext<Test.TestStreaming.DoStreamIParams.Reader> context) {
+            iSum += context.getParams().getI();
+            fulfiller = new CompletableFuture<>();
+            return fulfiller;
+        }
+
+        @Override
+        protected CompletableFuture<java.lang.Void> doStreamJ(StreamingCallContext<Test.TestStreaming.DoStreamJParams.Reader> context) {
+            context.allowCancellation();
+            jSum += context.getParams().getJ();
+            if (jShouldThrow) {
+                return CompletableFuture.failedFuture(RpcException.failed("throw requested"));
+            }
+            fulfiller = new CompletableFuture<>();
+            return fulfiller;
+        }
+
+        @Override
+        protected CompletableFuture<java.lang.Void> finishStream(CallContext<Test.TestStreaming.FinishStreamParams.Reader, Test.TestStreaming.FinishStreamResults.Builder> context) {
+            var results = context.getResults();
+            results.setTotalI(iSum);
+            results.setTotalJ(jSum);
+            return READY_NOW;
+        }
+    }
 }
 

runtime-rpc/src/test/schema/test.capnp

@@ -95,6 +95,13 @@ interface TestTailCaller {
   foo @0 (i :Int32, callee :TestTailCallee) -> TestTailCallee.TailResult;
 }
 
+interface TestStreaming {
+    doStreamI @0 (i: UInt32) -> stream;
+    doStreamJ @1 (j: UInt32) -> stream;
+    finishStream @2 () -> (totalI :UInt32, totalJ: UInt32);
+    # Test streaming. finishStream() returns the totals of the values streamed to the other calls.
+}
+
 interface TestHandle {}
 
 interface TestMoreStuff extends(TestCallOrder) {

runtime/src/main/java/org/capnproto/AnyPointer.java

@@ -21,6 +21,8 @@
 
 package org.capnproto;
 
+import java.util.concurrent.CompletableFuture;
+
 public final class AnyPointer {
     public static final class Factory
             implements PointerFactory<Builder, Reader>,
@@ -209,6 +211,11 @@ public final class AnyPointer {
             return this;
         }
 
+        @Override
+        public org.capnproto.Request<Builder> getBaseRequest() {
+            return this;
+        }
+
         @Override
         public RequestHook getHook() {
             return this.requestHook;
@@ -228,4 +235,44 @@ public final class AnyPointer {
             return this.requestHook.send();
         }
     }
+
+    public static final class StreamingRequest
+            implements org.capnproto.StreamingRequest<Builder> {
+
+        private final Builder params;
+        private final RequestHook requestHook;
+
+        StreamingRequest(AnyPointer.Request request) {
+            this(request.params, request.requestHook);
+        }
+
+        StreamingRequest(Builder params, RequestHook requestHook) {
+            this.params = params;
+            this.requestHook = requestHook;
+        }
+
+        @Override
+        public Builder getParams() {
+            return this.params;
+        }
+
+        @Override
+        public org.capnproto.StreamingRequest<Builder> getTypelessRequest() {
+            return this;
+        }
+
+        @Override
+        public RequestHook getHook() {
+            return this.requestHook;
+        }
+
+        @Override
+        public FromPointerBuilder<Builder> getParamsFactory() {
+            return AnyPointer.factory;
+        }
+
+        public CompletableFuture<java.lang.Void> send() {
+            return this.requestHook.sendStreaming();
+        }
+    }
 }

runtime/src/main/java/org/capnproto/Capability.java

@@ -87,14 +87,40 @@ public final class Capability {
             return CompletableFuture.completedFuture(null);
         }
 
-        default Request<AnyPointer.Builder> newCall(long interfaceId, short methodId) {
-            return this.getHook().newCall(interfaceId, methodId);
+        default <T> Request<T> newCall(FromPointerBuilder<T> paramsFactory, long interfaceId, short methodId) {
+            var request = this.getHook().newCall(interfaceId, methodId);
+            return new Request<>() {
+                @Override
+                public FromPointerBuilder<T> getParamsFactory() {
+                    return paramsFactory;
                 }
 
-        default <T> StreamingRequest<T> newStreamingCall(FromPointerBuilder<T> paramsBuilder,
-                                                           long interfaceId, short methodId) {
-            var request = getHook().newCall(interfaceId, methodId);
-            return new StreamingRequest<> (paramsBuilder, request.getParams(), request.getHook());
+                @Override
+                public Request<AnyPointer.Builder> getTypelessRequest() {
+                    return request;
+                }
+
+                @Override
+                public Request<T> getBaseRequest() {
+                    return this;
+                }
+            };
+        }
+
+        default <T> StreamingRequest<T> newStreamingCall(FromPointerBuilder<T> paramsFactory, long interfaceId, short methodId) {
+            var request =  this.getHook().newCall(interfaceId, methodId);
+            var streamingRequest = new AnyPointer.StreamingRequest(request.getParams(), request.getHook());
+            return new StreamingRequest<>() {
+                @Override
+                public FromPointerBuilder<T> getParamsFactory() {
+                    return paramsFactory;
+                }
+
+                @Override
+                public StreamingRequest<AnyPointer.Builder> getTypelessRequest() {
+                    return streamingRequest;
+                }
+            };
         }
     }
 
@@ -377,10 +403,10 @@ public final class Capability {
         }
 
         @Override
-        public CompletableFuture<?> sendStreaming() {
+        public CompletableFuture<java.lang.Void> sendStreaming() {
             // We don't do any special handling of streaming in RequestHook for local requests, because
             // there is no latency to compensate for between the client and server in this case.
-            return send();
+            return send().thenApply(results -> null);
         }
 
         @Override

runtime/src/main/java/org/capnproto/Request.java

@@ -2,23 +2,17 @@ package org.capnproto;
 
 import java.util.concurrent.CompletableFuture;
 
-public interface Request<Params> {
+public interface Request<Params>
+    extends RequestBase<Params> {
 
-    FromPointerBuilder<Params> getParamsFactory();
+    RequestBase<Params> getBaseRequest();
 
-    Request<AnyPointer.Builder> getTypelessRequest();
-
-    default Params getParams() {
-        return this.getTypelessRequest().getParams().getAs(this.getParamsFactory());
+    default FromPointerBuilder<Params> getParamsFactory() {
+        return getBaseRequest().getParamsFactory();
     }
 
-    default RequestHook getHook() {
-        return this.getTypelessRequest().getHook();
-    }
-
-
-    default RemotePromise<AnyPointer.Reader> sendInternal() {
-        return this.getTypelessRequest().sendInternal();
+    default RequestBase<AnyPointer.Builder> getTypelessRequest() {
+        return getBaseRequest().getTypelessRequest();
     }
 
     static <Params> Request<Params> newBrokenRequest(FromPointerBuilder<Params> paramsFactory,
@@ -34,7 +28,7 @@ public interface Request<Params> {
             }
 
             @Override
-            public CompletableFuture<?> sendStreaming() {
+            public CompletableFuture<java.lang.Void> sendStreaming() {
                 return CompletableFuture.failedFuture(exc);
             }
         };
@@ -46,9 +40,14 @@ public interface Request<Params> {
             }
 
             @Override
-            public Request<AnyPointer.Builder> getTypelessRequest() {
+            public RequestBase<AnyPointer.Builder> getTypelessRequest() {
                 return new AnyPointer.Request(message.getRoot(AnyPointer.factory), hook);
             }
+
+            @Override
+            public Request<Params> getBaseRequest() {
+                return this;
+            }
         };
     }
 
@@ -65,6 +64,11 @@ public interface Request<Params> {
             public Request<AnyPointer.Builder> getTypelessRequest() {
                 return typeless;
             }
+
+            @Override
+            public Request<Params> getBaseRequest() {
+                return this;
+            }
         };
     }
 }

runtime/src/main/java/org/capnproto/RequestBase.java

@@ -0,0 +1,20 @@
+package org.capnproto;
+
+public interface RequestBase<Params> {
+
+    FromPointerBuilder<Params> getParamsFactory();
+
+    RequestBase<AnyPointer.Builder> getTypelessRequest();
+
+    default Params getParams() {
+        return this.getTypelessRequest().getParams().getAs(this.getParamsFactory());
+    }
+
+    default RequestHook getHook() {
+        return this.getTypelessRequest().getHook();
+    }
+
+    default RemotePromise<AnyPointer.Reader> sendInternal() {
+        return this.getTypelessRequest().sendInternal();
+    }
+}

runtime/src/main/java/org/capnproto/RequestHook.java

@@ -1,12 +1,12 @@
 package org.capnproto;
 
-import java.util.concurrent.CompletionStage;
+import java.util.concurrent.CompletableFuture;
 
 public interface RequestHook {
 
     RemotePromise<AnyPointer.Reader> send();
 
-    CompletionStage<?> sendStreaming();
+    CompletableFuture<java.lang.Void> sendStreaming();
 
     default Object getBrand() {
         return null;

runtime/src/main/java/org/capnproto/StreamingCallContext.java

@@ -2,12 +2,20 @@ package org.capnproto;
 
 public class StreamingCallContext<Params> {
 
-    private final FromPointerReader<Params> params;
-    final CallContextHook hook;
+    private final FromPointerReader<Params> paramsFactory;
+    private final CallContextHook hook;
 
-    public StreamingCallContext(FromPointerReader<Params> params,
+    public StreamingCallContext(FromPointerReader<Params> paramsFactory,
                                 CallContextHook hook) {
-        this.params = params;
+        this.paramsFactory = paramsFactory;
         this.hook = hook;
     }
+
+    public final Params getParams() {
+        return this.hook.getParams().getAs(paramsFactory);
+    }
+
+    public final void allowCancellation() {
+        this.hook.allowCancellation();
+    }
 }

runtime/src/main/java/org/capnproto/StreamingRequest.java

@@ -1,26 +1,23 @@
 package org.capnproto;
 
-
 import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.CompletionStage;
 
-public class StreamingRequest<Params> {
+public interface StreamingRequest<Params> {
 
-    private final FromPointerBuilder<Params> paramsBuilder;
-    AnyPointer.Builder params;
-    RequestHook hook;
+    FromPointerBuilder<Params> getParamsFactory();
 
-    StreamingRequest(FromPointerBuilder<Params> paramsBuilder,
-                     AnyPointer.Builder params, RequestHook hook) {
-        this.paramsBuilder = paramsBuilder;
-        this.params = params;
-        this.hook = hook;
+    StreamingRequest<AnyPointer.Builder> getTypelessRequest();
+
+    default Params getParams() {
+        return this.getTypelessRequest().getParams().getAs(this.getParamsFactory());
     }
 
-    CompletionStage<?> send() {
-        var promise = hook.sendStreaming();
-        hook = null; // prevent reuse
-        return promise;
+    default RequestHook getHook() {
+        return this.getTypelessRequest().getHook();
+    }
+
+    default CompletableFuture<java.lang.Void> send() {
+        return this.getHook().sendStreaming();
     }
 }