Rename both Bridge classes to differentiate

Switching between them became a bit confusing.

src/plugin/host-bridge.h

@@ -0,0 +1,95 @@
+// yabridge: a Wine VST bridge
+// Copyright (C) 2020  Robbert van der Helm
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include <vestige/aeffect.h>
+
+#include <boost/asio/io_context.hpp>
+#include <boost/asio/local/stream_protocol.hpp>
+#include <boost/process/child.hpp>
+// TODO: Remove
+#include <thread>
+
+/**
+ * This handles the communication between the Linux native VST plugin and the
+ * Wine VST host. The functions below should be used as callback functions in an
+ * `AEffect` object.
+ */
+class HostBridge {
+   public:
+    /**
+     * Initializes the Wine VST bridge. This sets up the sockets for event
+     * handling.
+     *
+     * TODO: Figure out whether shared memory gives us better throughput and/or
+     *       lower overhead than using a Unix domain socket would.
+     *
+     * @param host_callback The callback function passed to the VST plugin by
+     *   the host.
+     *
+     * @throw std::runtime_error Thrown when the VST host could not be found, or
+     *   if it could not locate and load a VST .dll file.
+     */
+    // TODO: The plugin struct should be created here, not passed in
+    HostBridge(AEffect* plugin, audioMasterCallback host_callback);
+
+    // The four below functions are the handlers from the VST2 API. They are
+    // called through proxy functions in `plugin.cpp`.
+
+    /**
+     * Handle an event sent by the VST host. Most of these opcodes will be
+     * passed through to the winelib VST host.
+     */
+    intptr_t dispatch(AEffect* plugin,
+                      int32_t opcode,
+                      int32_t index,
+                      intptr_t value,
+                      void* data,
+                      float option);
+    void process(AEffect* plugin,
+                 float** inputs,
+                 float** outputs,
+                 int32_t sample_frames);
+    void set_parameter(AEffect* plugin, int32_t index, float value);
+    float get_parameter(AEffect* plugin, int32_t index);
+
+    // TODO: Remove debug loop
+    void host_callback_loop(AEffect* plugin);
+
+   private:
+    boost::asio::io_context io_context;
+    boost::asio::local::stream_protocol::endpoint socket_endpoint;
+    boost::asio::local::stream_protocol::acceptor socket_acceptor;
+
+    // The naming convention for these sockets is `<from>_<to>_<event>`. For
+    // instance the socket named `host_vst_dispatch` forwards
+    // `AEffect.dispatch()` calls from the native VST host to the Windows VST
+    // plugin (through the Wine VST host).
+    boost::asio::local::stream_protocol::socket host_vst_dispatch;
+    boost::asio::local::stream_protocol::socket vst_host_callback;
+
+    /**
+     * The callback function passed by the host to the VST plugin instance.
+     */
+    audioMasterCallback host_callback_function;
+    // TODO: Remove
+    std::thread removeme;
+    /**
+     * The Wine process hosting the Windows VST plugin.
+     */
+    boost::process::child vst_host;
+};