Move VectorStream to a new YaBStream

We'll have to extend this with `IStreamAttributes` for VST 3.6.0 preset
meta data.

src/common/serialization/vst3/bstream.h

@@ -0,0 +1,85 @@
+// yabridge: a Wine VST bridge
+// Copyright (C) 2020-2021 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 <pluginterfaces/base/ibstream.h>
+
+#include "base.h"
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+
+/**
+ * Serialize an `IBStream` into an `std::vector<uint8_t>`, and allow the
+ * receiving side to use it as an `IBStream` again. `ISizeableStream` is defined
+ * but then for whatever reason never used, but we'll implement it anyways.
+ */
+class YaBStream : public Steinberg::IBStream,
+                  public Steinberg::ISizeableStream {
+   public:
+    YaBStream();
+
+    /**
+     * Read an existing stream.
+     *
+     * @throw std::runtime_error If we couldn't read from the stream.
+     */
+    YaBStream(Steinberg::IBStream* stream);
+
+    virtual ~YaBStream();
+
+    DECLARE_FUNKNOWN_METHODS
+
+    /**
+     * Write the vector buffer back to an IBStream. After writing the seek
+     * position will be left at the end of the stream.
+     */
+    tresult write_back(Steinberg::IBStream* stream) const;
+
+    /**
+     * Return the buffer's, used in the logging messages.
+     */
+    size_t size() const;
+
+    // From `IBstream`
+    tresult PLUGIN_API read(void* buffer,
+                            int32 numBytes,
+                            int32* numBytesRead = nullptr) override;
+    tresult PLUGIN_API write(void* buffer,
+                             int32 numBytes,
+                             int32* numBytesWritten = nullptr) override;
+    tresult PLUGIN_API seek(int64 pos,
+                            int32 mode,
+                            int64* result = nullptr) override;
+    tresult PLUGIN_API tell(int64* pos) override;
+
+    // From `ISizeableStream`
+    tresult PLUGIN_API getStreamSize(int64& size) override;
+    tresult PLUGIN_API setStreamSize(int64 size) override;
+
+    template <typename S>
+    void serialize(S& s) {
+        s.container1b(buffer, max_vector_stream_size);
+        // The seek position should always be initialized at 0
+    }
+
+   private:
+    std::vector<uint8_t> buffer;
+    size_t seek_position = 0;
+};
+
+#pragma GCC diagnostic pop