Remove virtual inheritance from Port hierarchy

This was confusing stoat, and is questionable design anyway.  The OutputPort
functionality has been moved to PortImpl, which is a basic port with buffers
suitable for use as an output, and is overridden by InputPort and DuplexPort
where necessary.

19 files changed, 130 insertions, 196 deletions

diff --git a/src/server/ArcImpl.cpp b/src/server/ArcImpl.cpp
index 8cdf02b4..1dd92d48 100644
--- a/src/server/ArcImpl.cpp
+++ b/src/server/ArcImpl.cpp
@@ -1,6 +1,6 @@
 /*
   This file is part of Ingen.
-  Copyright 2007-2015 David Robillard <http://drobilla.net/>
+  Copyright 2007-2016 David Robillard <http://drobilla.net/>
 
   Ingen is free software: you can redistribute it and/or modify it under the
   terms of the GNU Affero General Public License as published by the Free
@@ -82,7 +82,7 @@ ArcImpl::must_mix() const
 }
 
 bool
-ArcImpl::can_connect(const OutputPort* src, const InputPort* dst)
+ArcImpl::can_connect(const PortImpl* src, const InputPort* dst)
 {
 	const Ingen::URIs& uris = src->bufs().uris();
 	return (
diff --git a/src/server/ArcImpl.hpp b/src/server/ArcImpl.hpp
index 01984ba6..c796384a 100644
--- a/src/server/ArcImpl.hpp
+++ b/src/server/ArcImpl.hpp
@@ -1,6 +1,6 @@
 /*
   This file is part of Ingen.
-  Copyright 2007-2015 David Robillard <http://drobilla.net/>
+  Copyright 2007-2016 David Robillard <http://drobilla.net/>
 
   Ingen is free software: you can redistribute it and/or modify it under the
   terms of the GNU Affero General Public License as published by the Free
@@ -32,7 +32,6 @@ namespace Ingen {
 namespace Server {
 
 class PortImpl;
-class OutputPort;
 class InputPort;
 
 /** Represents a single inbound connection for an InputPort.
@@ -72,7 +71,7 @@ public:
 	/** Whether this arc must mix down voices into a local buffer */
 	bool must_mix() const;
 
-	static bool can_connect(const OutputPort* src, const InputPort* dst);
+	static bool can_connect(const PortImpl* src, const InputPort* dst);
 
 protected:
 	PortImpl* const _tail;
diff --git a/src/server/DuplexPort.cpp b/src/server/DuplexPort.cpp
index 7e0e3cce..5eff4add 100644
--- a/src/server/DuplexPort.cpp
+++ b/src/server/DuplexPort.cpp
@@ -1,6 +1,6 @@
 /*
   This file is part of Ingen.
-  Copyright 2007-2015 David Robillard <http://drobilla.net/>
+  Copyright 2007-2016 David Robillard <http://drobilla.net/>
 
   Ingen is free software: you can redistribute it and/or modify it under the
   terms of the GNU Affero General Public License as published by the Free
@@ -21,7 +21,6 @@
 #include "DuplexPort.hpp"
 #include "Engine.hpp"
 #include "GraphImpl.hpp"
-#include "OutputPort.hpp"
 
 using namespace std;
 
@@ -38,10 +37,7 @@ DuplexPort::DuplexPort(BufferFactory&      bufs,
                        size_t              buf_size,
                        const Atom&         value,
                        bool                is_output)
-	: PortImpl(bufs, parent, symbol, index, parent->polyphony(), type, buf_type, value, buf_size)
-	, InputPort(bufs, parent, symbol, index, parent->polyphony(), type, buf_type, value, buf_size)
-	, OutputPort(bufs, parent, symbol, index, parent->polyphony(), type, buf_type, value, buf_size)
-	, _is_output(is_output)
+	: InputPort(bufs, parent, symbol, index, parent->polyphony(), type, buf_type, value, buf_size)
 {
 	if (polyphonic) {
 		set_property(bufs.uris().ingen_polyphonic, bufs.forge().make(true));
@@ -57,6 +53,16 @@ DuplexPort::DuplexPort(BufferFactory&      bufs,
 		set_property(bufs.uris().lv2_minimum, bufs.forge().make(0.0f));
 		set_property(bufs.uris().lv2_maximum, bufs.forge().make(1.0f));
 	}
+
+	_is_output = is_output;
+	if (is_output) {
+		if (parent->graph_type() != Node::GraphType::GRAPH) {
+			remove_property(bufs.uris().rdf_type, bufs.uris().lv2_InputPort.urid);
+			add_property(bufs.uris().rdf_type, bufs.uris().lv2_OutputPort.urid);
+		}
+	}
+
+	get_buffers(bufs, _voices, parent->polyphony(), false);
 }
 
 DuplexPort::~DuplexPort()
@@ -132,7 +138,7 @@ DuplexPort::get_buffers(BufferFactory&      bufs,
 		if (_is_output) {
 			return InputPort::get_buffers(bufs, voices, poly, real_time);
 		} else {
-			return OutputPort::get_buffers(bufs, voices, poly, real_time);
+			return PortImpl::get_buffers(bufs, voices, poly, real_time);
 		}
 	}
 	return false;
@@ -215,13 +221,13 @@ DuplexPort::post_process(RunContext& context)
 SampleCount
 DuplexPort::next_value_offset(SampleCount offset, SampleCount end) const
 {
-	return OutputPort::next_value_offset(offset, end);
+	return PortImpl::next_value_offset(offset, end);
 }
 
 void
 DuplexPort::update_values(SampleCount offset, uint32_t voice)
 {
-	return OutputPort::update_values(offset, voice);
+	return PortImpl::update_values(offset, voice);
 }
 
 } // namespace Server
diff --git a/src/server/DuplexPort.hpp b/src/server/DuplexPort.hpp
index 836faa36..adf32a88 100644
--- a/src/server/DuplexPort.hpp
+++ b/src/server/DuplexPort.hpp
@@ -1,6 +1,6 @@
 /*
   This file is part of Ingen.
-  Copyright 2007-2015 David Robillard <http://drobilla.net/>
+  Copyright 2007-2016 David Robillard <http://drobilla.net/>
 
   Ingen is free software: you can redistribute it and/or modify it under the
   terms of the GNU Affero General Public License as published by the Free
@@ -21,14 +21,13 @@
 
 #include "BufferRef.hpp"
 #include "InputPort.hpp"
-#include "OutputPort.hpp"
 
 namespace Ingen {
 namespace Server {
 
 class BlockImpl;
 
-/** A duplex Port (both an InputPort and an OutputPort on a Graph)
+/** A duplex Port (both an input and output port on a Graph)
  *
  * This is used for Graph ports, since they need to appear as both an input and
  * an output port based on context.  There are no actual duplex ports in Ingen,
@@ -38,7 +37,6 @@ class BlockImpl;
  * \ingroup engine
  */
 class DuplexPort : public InputPort
-                 , public OutputPort
                  , public boost::intrusive::slist_base_hook<>  // In GraphImpl
 {
 public:
@@ -91,12 +89,6 @@ public:
 
 	SampleCount next_value_offset(SampleCount offset, SampleCount end) const;
 	void        update_values(SampleCount offset, uint32_t voice);
-
-	bool is_input()  const { return !_is_output; }
-	bool is_output() const { return _is_output; }
-
-protected:
-	bool _is_output;
 };
 
 } // namespace Server
diff --git a/src/server/GraphImpl.hpp b/src/server/GraphImpl.hpp
index f7d0be32..57e60792 100644
--- a/src/server/GraphImpl.hpp
+++ b/src/server/GraphImpl.hpp
@@ -123,11 +123,13 @@ public:
 
 	void add_input(DuplexPort& port) {
 		ThreadManager::assert_thread(THREAD_PRE_PROCESS);
+		assert(port.is_input());
 		_inputs.push_front(port);
 	}
 
 	void add_output(DuplexPort& port) {
 		ThreadManager::assert_thread(THREAD_PRE_PROCESS);
+		assert(port.is_output());
 		_outputs.push_front(port);
 	}
 
diff --git a/src/server/InputPort.cpp b/src/server/InputPort.cpp
index 4e1ced3e..61ce0c05 100644
--- a/src/server/InputPort.cpp
+++ b/src/server/InputPort.cpp
@@ -1,6 +1,6 @@
 /*
   This file is part of Ingen.
-  Copyright 2007-2015 David Robillard <http://drobilla.net/>
+  Copyright 2007-2016 David Robillard <http://drobilla.net/>
 
   Ingen is free software: you can redistribute it and/or modify it under the
   terms of the GNU Affero General Public License as published by the Free
@@ -27,7 +27,6 @@
 #include "Engine.hpp"
 #include "GraphImpl.hpp"
 #include "InputPort.hpp"
-#include "OutputPort.hpp"
 #include "RunContext.hpp"
 #include "mix.hpp"
 
@@ -45,7 +44,7 @@ InputPort::InputPort(BufferFactory&      bufs,
                      LV2_URID            buffer_type,
                      const Atom&         value,
                      size_t              buffer_size)
-	: PortImpl(bufs, parent, symbol, index, poly, type, buffer_type, value, buffer_size)
+	: PortImpl(bufs, parent, symbol, index, poly, type, buffer_type, value, buffer_size, false)
 	, _num_arcs(0)
 {
 	const Ingen::URIs& uris = bufs.uris();
@@ -118,7 +117,7 @@ InputPort::add_arc(RunContext& context, ArcImpl* c)
 }
 
 ArcImpl*
-InputPort::remove_arc(RunContext& context, const OutputPort* tail)
+InputPort::remove_arc(RunContext& context, const PortImpl* tail)
 {
 	ArcImpl* arc = NULL;
 	for (Arcs::iterator i = _arcs.begin(); i != _arcs.end(); ++i) {
diff --git a/src/server/InputPort.hpp b/src/server/InputPort.hpp
index f93aa4df..1a27ac93 100644
--- a/src/server/InputPort.hpp
+++ b/src/server/InputPort.hpp
@@ -1,6 +1,6 @@
 /*
   This file is part of Ingen.
-  Copyright 2007-2015 David Robillard <http://drobilla.net/>
+  Copyright 2007-2016 David Robillard <http://drobilla.net/>
 
   Ingen is free software: you can redistribute it and/or modify it under the
   terms of the GNU Affero General Public License as published by the Free
@@ -32,7 +32,6 @@ namespace Server {
 
 class ArcImpl;
 class BlockImpl;
-class OutputPort;
 class RunContext;
 
 /** An input port on a Block or Graph.
@@ -46,7 +45,7 @@ class RunContext;
  *
  * \ingroup engine
  */
-class InputPort : virtual public PortImpl
+class InputPort : public PortImpl
 {
 public:
 	InputPort(BufferFactory&      bufs,
@@ -83,8 +82,8 @@ public:
 	 *
 	 * setup_buffers() must be called later for the change to take effect.
 	 */
-	ArcImpl* remove_arc(RunContext&       context,
-	                    const OutputPort* tail);
+	ArcImpl* remove_arc(RunContext&     context,
+	                    const PortImpl* tail);
 
 	/** Set `voices` as the buffers to be used for this port.
 	 *
@@ -111,9 +110,6 @@ public:
 	void increment_num_arcs() { ++_num_arcs; }
 	void decrement_num_arcs() { --_num_arcs; }
 
-	bool is_input()  const { return true; }
-	bool is_output() const { return false; }
-
 	bool direct_connect() const;
 
 protected:
diff --git a/src/server/LV2Block.cpp b/src/server/LV2Block.cpp
index c20abfda..be02f3ed 100644
--- a/src/server/LV2Block.cpp
+++ b/src/server/LV2Block.cpp
@@ -43,6 +43,7 @@
 #include "LV2Block.hpp"
 #include "LV2Plugin.hpp"
 #include "OutputPort.hpp"
+#include "PortImpl.hpp"
 #include "RunContext.hpp"
 #include "Worker.hpp"
 
diff --git a/src/server/OutputPort.cpp b/src/server/OutputPort.cpp
deleted file mode 100644
index 4121c6a9..00000000
--- a/src/server/OutputPort.cpp
+++ /dev/null
@@ -1,99 +0,0 @@
-/*
-  This file is part of Ingen.
-  Copyright 2007-2015 David Robillard <http://drobilla.net/>
-
-  Ingen is free software: you can redistribute it and/or modify it under the
-  terms of the GNU Affero General Public License as published by the Free
-  Software Foundation, either version 3 of the License, or any later version.
-
-  Ingen is distributed in the hope that it will be useful, but WITHOUT ANY
-  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
-  A PARTICULAR PURPOSE.  See the GNU Affero General Public License for details.
-
-  You should have received a copy of the GNU Affero General Public License
-  along with Ingen.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-#include "ingen/URIs.hpp"
-
-#include "Buffer.hpp"
-#include "BufferFactory.hpp"
-#include "Engine.hpp"
-#include "BlockImpl.hpp"
-#include "OutputPort.hpp"
-
-using namespace std;
-
-namespace Ingen {
-namespace Server {
-
-OutputPort::OutputPort(BufferFactory&      bufs,
-                       BlockImpl*          parent,
-                       const Raul::Symbol& symbol,
-                       uint32_t            index,
-                       uint32_t            poly,
-                       PortType            type,
-                       LV2_URID            buffer_type,
-                       const Atom&         value,
-                       size_t              buffer_size)
-	: PortImpl(bufs, parent, symbol, index, poly, type, buffer_type, value, buffer_size)
-{
-	if (parent->graph_type() != Node::GraphType::GRAPH) {
-		add_property(bufs.uris().rdf_type, bufs.uris().lv2_OutputPort.urid);
-	}
-
-	setup_buffers(bufs, poly, false);
-}
-
-bool
-OutputPort::get_buffers(BufferFactory&      bufs,
-                        Raul::Array<Voice>* voices,
-                        uint32_t            poly,
-                        bool                real_time) const
-{
-	for (uint32_t v = 0; v < poly; ++v)
-		voices->at(v).buffer = bufs.get_buffer(
-			buffer_type(), _value.type(), _buffer_size, real_time);
-
-	return true;
-}
-
-void
-OutputPort::pre_process(RunContext& context)
-{
-	for (uint32_t v = 0; v < _poly; ++v)
-		_voices->at(v).buffer->prepare_output_write(context);
-}
-
-SampleCount
-OutputPort::next_value_offset(SampleCount offset, SampleCount end) const
-{
-	SampleCount earliest = end;
-	for (uint32_t v = 0; v < _poly; ++v) {
-		const SampleCount o = _voices->at(v).buffer->next_value_offset(offset, end);
-		if (o < earliest) {
-			earliest = o;
-		}
-	}
-	return earliest;
-}
-
-void
-OutputPort::update_values(SampleCount offset, uint32_t voice)
-{
-	_voices->at(voice).buffer->update_value_buffer(offset);
-}
-
-void
-OutputPort::post_process(RunContext& context)
-{
-	for (uint32_t v = 0; v < _poly; ++v) {
-		update_set_state(context, v);
-		update_values(0, v);
-	}
-
-	monitor(context);
-}
-
-} // namespace Server
-} // namespace Ingen
diff --git a/src/server/OutputPort.hpp b/src/server/OutputPort.hpp
index 68c79768..1058defb 100644
--- a/src/server/OutputPort.hpp
+++ b/src/server/OutputPort.hpp
@@ -1,6 +1,6 @@
 /*
   This file is part of Ingen.
-  Copyright 2007-2015 David Robillard <http://drobilla.net/>
+  Copyright 2007-2016 David Robillard <http://drobilla.net/>
 
   Ingen is free software: you can redistribute it and/or modify it under the
   terms of the GNU Affero General Public License as published by the Free
@@ -17,8 +17,6 @@
 #ifndef INGEN_ENGINE_OUTPUTPORT_HPP
 #define INGEN_ENGINE_OUTPUTPORT_HPP
 
-#include <cstdlib>
-
 #include "PortImpl.hpp"
 
 namespace Ingen {
@@ -27,11 +25,11 @@ namespace Server {
 /** An output port.
  *
  * Output ports always have a locally allocated buffer, and buffer() will
- * always return that buffer.  (This is very different from InputPort)
+ * always return that buffer.
  *
  * \ingroup engine
  */
-class OutputPort : virtual public PortImpl
+class OutputPort : public PortImpl
 {
 public:
 	OutputPort(BufferFactory&      bufs,
@@ -42,23 +40,9 @@ public:
 	           PortType            type,
 	           LV2_URID            buffer_type,
 	           const Atom&         value,
-	           size_t              buffer_size = 0);
-
-	virtual ~OutputPort() {}
-
-	bool get_buffers(BufferFactory&      bufs,
-	                 Raul::Array<Voice>* voices,
-	                 uint32_t            poly,
-	                 bool                real_time) const;
-
-	void pre_process(RunContext& context);
-	void post_process(RunContext& context);
-
-	SampleCount next_value_offset(SampleCount offset, SampleCount end) const;
-	void        update_values(SampleCount offset, uint32_t voice);
-
-	bool is_input()  const { return false; }
-	bool is_output() const { return true; }
+	           size_t              buffer_size = 0)
+		: PortImpl(bufs, parent, symbol, index,poly, type, buffer_type, value, buffer_size, true)
+	{}
 };
 
 } // namespace Server
diff --git a/src/server/PortImpl.cpp b/src/server/PortImpl.cpp
index 1f1b3695..669e4b9d 100644
--- a/src/server/PortImpl.cpp
+++ b/src/server/PortImpl.cpp
@@ -51,7 +51,8 @@ PortImpl::PortImpl(BufferFactory&      bufs,
                    PortType            type,
                    LV2_URID            buffer_type,
                    const Atom&         value,
-                   size_t              buffer_size)
+                   size_t              buffer_size,
+                   bool                is_output)
 	: NodeImpl(bufs.uris(), block, name)
 	, _bufs(bufs)
 	, _index(index)
@@ -75,6 +76,7 @@ PortImpl::PortImpl(BufferFactory&      bufs,
 	, _is_sample_rate(false)
 	, _is_toggled(false)
 	, _is_driver_port(false)
+	, _is_output(is_output)
 {
 	assert(block != NULL);
 	assert(_poly > 0);
@@ -91,6 +93,14 @@ PortImpl::PortImpl(BufferFactory&      bufs,
 		set_property(uris.atom_bufferType,
 		             bufs.forge().make_urid(buffer_type));
 	}
+
+	if (is_output) {
+		if (_parent->graph_type() != Node::GraphType::GRAPH) {
+			add_property(bufs.uris().rdf_type, bufs.uris().lv2_OutputPort.urid);
+		}
+
+		setup_buffers(bufs, poly, false);
+	}
 }
 
 PortImpl::~PortImpl()
@@ -98,6 +108,19 @@ PortImpl::~PortImpl()
 	delete _voices;
 }
 
+bool
+PortImpl::get_buffers(BufferFactory&      bufs,
+                      Raul::Array<Voice>* voices,
+                      uint32_t            poly,
+                      bool                real_time) const
+{
+	for (uint32_t v = 0; v < poly; ++v)
+		voices->at(v).buffer = bufs.get_buffer(
+			buffer_type(), _value.type(), _buffer_size, real_time);
+
+	return true;
+}
+
 void
 PortImpl::set_type(PortType port_type, LV2_URID buffer_type)
 {
@@ -505,7 +528,38 @@ PortImpl::value_buffer(uint32_t voice)
 SampleCount
 PortImpl::next_value_offset(SampleCount offset, SampleCount end) const
 {
-	return end;
+	SampleCount earliest = end;
+	for (uint32_t v = 0; v < _poly; ++v) {
+		const SampleCount o = _voices->at(v).buffer->next_value_offset(offset, end);
+		if (o < earliest) {
+			earliest = o;
+		}
+	}
+	return earliest;
+}
+
+void
+PortImpl::update_values(SampleCount offset, uint32_t voice)
+{
+	_voices->at(voice).buffer->update_value_buffer(offset);
+}
+
+void
+PortImpl::pre_process(RunContext& context)
+{
+	for (uint32_t v = 0; v < _poly; ++v)
+		_voices->at(v).buffer->prepare_output_write(context);
+}
+
+void
+PortImpl::post_process(RunContext& context)
+{
+	for (uint32_t v = 0; v < _poly; ++v) {
+		update_set_state(context, v);
+		update_values(0, v);
+	}
+
+	monitor(context);
 }
 
 } // namespace Server
diff --git a/src/server/PortImpl.hpp b/src/server/PortImpl.hpp
index 94fdd50c..05ca3ff4 100644
--- a/src/server/PortImpl.hpp
+++ b/src/server/PortImpl.hpp
@@ -1,6 +1,6 @@
 /*
   This file is part of Ingen.
-  Copyright 2007-2015 David Robillard <http://drobilla.net/>
+  Copyright 2007-2016 David Robillard <http://drobilla.net/>
 
   Ingen is free software: you can redistribute it and/or modify it under the
   terms of the GNU Affero General Public License as published by the Free
@@ -38,6 +38,10 @@ class BufferFactory;
 
 /** A port (input or output) on a Block.
  *
+ * The base implementation here is general and/or for output ports (which are
+ * simplest), InputPort and DuplexPort override functions to provide
+ * specialized behaviour where necessary.
+ *
  * \ingroup engine
  */
 class PortImpl : public NodeImpl
@@ -80,6 +84,17 @@ public:
 		BufferRef buffer;
 	};
 
+	PortImpl(BufferFactory&      bufs,
+	         BlockImpl*          block,
+	         const Raul::Symbol& name,
+	         uint32_t            index,
+	         uint32_t            poly,
+	         PortType            type,
+	         LV2_URID            buffer_type,
+	         const Atom&         value,
+	         size_t              buffer_size = 0,
+	         bool                is_output = true);
+
 	~PortImpl();
 
 	virtual GraphType graph_type() const { return GraphType::PORT; }
@@ -153,9 +168,9 @@ public:
 	bool is_driver_port() const { return _is_driver_port; }
 
 	/** Called once per process cycle */
-	virtual void pre_process(RunContext& context) = 0;
+	virtual void pre_process(RunContext& context);
 	virtual void pre_run(RunContext& context) {}
-	virtual void post_process(RunContext& context) = 0;
+	virtual void post_process(RunContext& context);
 
 	/** Empty buffer contents completely (ie silence) */
 	virtual void clear_buffers();
@@ -164,7 +179,7 @@ public:
 	virtual bool get_buffers(BufferFactory&      bufs,
 	                         Raul::Array<Voice>* voices,
 	                         uint32_t            poly,
-	                         bool                real_time) const = 0;
+	                         bool                real_time) const;
 
 	void setup_buffers(BufferFactory& bufs, uint32_t poly, bool real_time) {
 		get_buffers(bufs, _voices, poly, real_time);
@@ -186,9 +201,6 @@ public:
 	virtual void connect_buffers(SampleCount offset=0);
 	virtual void recycle_buffers();
 
-	virtual bool is_input()  const = 0;
-	virtual bool is_output() const = 0;
-
 	uint32_t index() const { return _index; }
 
 	inline bool is_a(PortType type) const { return _type == type; }
@@ -238,7 +250,7 @@ public:
 	                                      SampleCount end) const;
 
 	/** Update value buffer for `voice` to be current as of `offset`. */
-	virtual void update_values(SampleCount offset, uint32_t voice) = 0;
+	virtual void update_values(SampleCount offset, uint32_t voice);
 
 	void force_monitor_update() { _force_monitor_update = true; }
 
@@ -251,6 +263,8 @@ public:
 
 	void cache_properties();
 
+	bool is_input()       const { return !_is_output; }
+	bool is_output()      const { return _is_output; }
 	bool is_morph()       const { return _is_morph; }
 	bool is_auto_morph()  const { return _is_auto_morph; }
 	bool is_logarithmic() const { return _is_logarithmic; }
@@ -258,16 +272,6 @@ public:
 	bool is_toggled()     const { return _is_toggled; }
 
 protected:
-	PortImpl(BufferFactory&      bufs,
-	         BlockImpl*          block,
-	         const Raul::Symbol& name,
-	         uint32_t            index,
-	         uint32_t            poly,
-	         PortType            type,
-	         LV2_URID            buffer_type,
-	         const Atom&         value,
-	         size_t              buffer_size);
-
 	BufferFactory&      _bufs;
 	uint32_t            _index;
 	uint32_t            _poly;
@@ -291,6 +295,7 @@ protected:
 	bool                _is_sample_rate;
 	bool                _is_toggled;
 	bool                _is_driver_port;
+	bool                _is_output;
 };
 
 } // namespace Server
diff --git a/src/server/events/Connect.cpp b/src/server/events/Connect.cpp
index 34dc569e..c24fc2bb 100644
--- a/src/server/events/Connect.cpp
+++ b/src/server/events/Connect.cpp
@@ -24,7 +24,6 @@
 #include "Engine.hpp"
 #include "GraphImpl.hpp"
 #include "InputPort.hpp"
-#include "OutputPort.hpp"
 #include "PortImpl.hpp"
 #include "PreProcessContext.hpp"
 #include "internals/BlockDelay.hpp"
@@ -64,8 +63,8 @@ Connect::pre_process(PreProcessContext& ctx)
 		return Event::pre_process_done(Status::NOT_FOUND, _head_path);
 	}
 
-	OutputPort* tail_output = dynamic_cast<OutputPort*>(tail);
-	_head                   = dynamic_cast<InputPort*>(head);
+	PortImpl* tail_output = dynamic_cast<PortImpl*>(tail);
+	_head                 = dynamic_cast<InputPort*>(head);
 	if (!tail_output || !_head) {
 		return Event::pre_process_done(Status::BAD_REQUEST, _head_path);
 	}
diff --git a/src/server/events/Connect.hpp b/src/server/events/Connect.hpp
index 9b98b167..359c9f3b 100644
--- a/src/server/events/Connect.hpp
+++ b/src/server/events/Connect.hpp
@@ -34,7 +34,6 @@ class ArcImpl;
 class CompiledGraph;
 class GraphImpl;
 class InputPort;
-class OutputPort;
 
 namespace Events {
 
diff --git a/src/server/events/CreatePort.cpp b/src/server/events/CreatePort.cpp
index 60e57a71..bb8bb4d4 100644
--- a/src/server/events/CreatePort.cpp
+++ b/src/server/events/CreatePort.cpp
@@ -141,7 +141,8 @@ CreatePort::pre_process(PreProcessContext& ctx)
 	                             polyphonic,
 	                             _port_type, _buf_type, buf_size,
 	                             value, _flow == Flow::OUTPUT);
-
+	assert((_flow == Flow::OUTPUT && _graph_port->is_output()) ||
+	       (_flow == Flow::INPUT && _graph_port->is_input()));
 	_graph_port->properties().insert(_properties.begin(), _properties.end());
 
 	_engine.store()->add(_graph_port);
diff --git a/src/server/events/Disconnect.cpp b/src/server/events/Disconnect.cpp
index 40b85c22..8875eb0c 100644
--- a/src/server/events/Disconnect.cpp
+++ b/src/server/events/Disconnect.cpp
@@ -27,7 +27,6 @@
 #include "Engine.hpp"
 #include "GraphImpl.hpp"
 #include "InputPort.hpp"
-#include "OutputPort.hpp"
 #include "PortImpl.hpp"
 #include "PreProcessContext.hpp"
 #include "RunContext.hpp"
@@ -61,7 +60,7 @@ Disconnect::~Disconnect()
 
 Disconnect::Impl::Impl(Engine&     e,
                        GraphImpl*  graph,
-                       OutputPort* t,
+                       PortImpl*   t,
                        InputPort*  h)
 	: _engine(e)
 	, _tail(t)
@@ -165,7 +164,7 @@ Disconnect::pre_process(PreProcessContext& ctx)
 
 	_impl = new Impl(_engine,
 	                 _graph,
-	                 dynamic_cast<OutputPort*>(tail),
+	                 dynamic_cast<PortImpl*>(tail),
 	                 dynamic_cast<InputPort*>(head));
 
 	if (ctx.must_compile(_graph)) {
diff --git a/src/server/events/Disconnect.hpp b/src/server/events/Disconnect.hpp
index 19ffcf3b..fa16f01f 100644
--- a/src/server/events/Disconnect.hpp
+++ b/src/server/events/Disconnect.hpp
@@ -33,7 +33,6 @@ namespace Server {
 
 class CompiledGraph;
 class InputPort;
-class OutputPort;
 class PortImpl;
 
 namespace Events {
@@ -61,19 +60,19 @@ public:
 
 	class Impl {
 	public:
-		Impl(Engine&     e,
-		     GraphImpl*  graph,
-		     OutputPort* t,
-		     InputPort*  h);
+		Impl(Engine&    e,
+		     GraphImpl* graph,
+		     PortImpl*  t,
+		     InputPort* h);
 
 		bool execute(RunContext& context, bool set_head_buffers);
 
-		inline OutputPort* tail() { return _tail; }
-		inline InputPort*  head() { return _head; }
+		inline PortImpl*  tail() { return _tail; }
+		inline InputPort* head() { return _head; }
 
 	private:
 		Engine&                       _engine;
-		OutputPort*                   _tail;
+		PortImpl*                     _tail;
 		InputPort*                    _head;
 		SPtr<ArcImpl>                 _arc;
 		Raul::Array<PortImpl::Voice>* _voices;
diff --git a/src/server/events/DisconnectAll.cpp b/src/server/events/DisconnectAll.cpp
index 8ce14e74..597f8e9b 100644
--- a/src/server/events/DisconnectAll.cpp
+++ b/src/server/events/DisconnectAll.cpp
@@ -29,7 +29,6 @@
 #include "Engine.hpp"
 #include "GraphImpl.hpp"
 #include "InputPort.hpp"
-#include "OutputPort.hpp"
 #include "PortImpl.hpp"
 #include "PreProcessContext.hpp"
 #include "events/Disconnect.hpp"
@@ -135,7 +134,7 @@ DisconnectAll::pre_process(PreProcessContext& ctx)
 	for (const auto& a : to_remove) {
 		_impls.push_back(new Disconnect::Impl(
 			                 _engine, _parent,
-			                 dynamic_cast<OutputPort*>(a->tail()),
+			                 dynamic_cast<PortImpl*>(a->tail()),
 			                 dynamic_cast<InputPort*>(a->head())));
 	}
 
diff --git a/src/server/wscript b/src/server/wscript
index 68c1c5f1..1d4b8ac2 100644
--- a/src/server/wscript
+++ b/src/server/wscript
@@ -22,7 +22,6 @@ def build(bld):
             LV2Block.cpp
             LV2Plugin.cpp
             NodeImpl.cpp
-            OutputPort.cpp
             PortImpl.cpp
             PostProcessor.cpp
             PreProcessor.cpp