From 8e117e0f47ae8051b6c26c90a21d8b2bd4e939de Mon Sep 17 00:00:00 2001
From: Patrick Wuttke <mewin@mewin.de>
Date: Sun, 15 Sep 2024 14:45:30 +0200
Subject: [PATCH] Added wrapper to allow passing Mijin streams to functions
 that expect an STL stream.

---
 source/mijin/io/stlstream.hpp | 93 +++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 source/mijin/io/stlstream.hpp

diff --git a/source/mijin/io/stlstream.hpp b/source/mijin/io/stlstream.hpp
new file mode 100644
index 0000000..e84aac7
--- /dev/null
+++ b/source/mijin/io/stlstream.hpp
@@ -0,0 +1,93 @@
+
+#pragma once
+
+#if !defined(MIJIN_IO_STLSTREAM_HPP_INCLUDED)
+#define MIJIN_IO_STLSTREAM_HPP_INCLUDED 1
+
+#include <array>
+#include <streambuf>
+#include "./stream.hpp"
+
+namespace mijin
+{
+
+//
+// public defines
+//
+
+//
+// public constants
+//
+
+//
+// public types
+//
+
+template<typename TChar, typename TTraits = std::char_traits<TChar>>
+class BasicStreambufAdapter : public std::basic_streambuf<TChar, TTraits>
+{
+private:
+    using base_t = std::basic_streambuf<TChar, TTraits>;
+    using char_type = base_t::char_type;
+    using int_type = base_t::int_type;
+    using traits_type = base_t::traits_type;
+
+    static const std::size_t BUFFER_SIZE = 4096;
+
+    Stream* stream_ = nullptr;
+    std::array<TChar, BUFFER_SIZE> inBuffer_;
+    std::array<TChar, BUFFER_SIZE> outBuffer_;
+public:
+    explicit BasicStreambufAdapter(Stream& stream) noexcept : stream_(&stream)
+    {
+        base_t::setp(outBuffer_.data(), outBuffer_.data() + outBuffer_.size());
+    }
+
+    int_type underflow() override
+    {
+        std::size_t bytesRead = 0;
+        while (bytesRead == 0)
+        {
+            if (stream_->isAtEnd())
+            {
+                return traits_type::eof();
+            }
+            throwOnError(stream_->readRaw(inBuffer_, {.partial = true}, &bytesRead));
+        }
+        base_t::setg(inBuffer_.data(), inBuffer_.data(), inBuffer_.data() + bytesRead);
+        return inBuffer_[0];
+    }
+
+    int_type overflow(int_type c) override
+    {
+        if (base_t::pptr() - base_t::pbase() > 0)
+        {
+            throwOnError(stream_->writeRaw(base_t::pbase(), base_t::pptr() - base_t::pbase()));
+        }
+        outBuffer_[0] = traits_type::to_char_type(c);
+        base_t::setp(outBuffer_.data() + 1, outBuffer_.data() + outBuffer_.size());
+        return traits_type::not_eof(c);
+    }
+
+    int sync() override
+    {
+        stream_->flush();
+        return 0;
+    }
+};
+
+using StreambufAdapter = BasicStreambufAdapter<char>;
+
+template<typename TChar, typename TTraits = std::char_traits<TChar>>
+class BasicIOStreamAdapter : public std::basic_iostream<TChar, TTraits>
+{
+private:
+    StreambufAdapter streambuf_;
+public:
+    BasicIOStreamAdapter(Stream& stream) noexcept : std::basic_iostream<TChar, TTraits>(&streambuf_), streambuf_(stream) {}
+};
+
+using IOStreamAdapter = BasicIOStreamAdapter<char>;
+} // namespace mijin
+
+#endif // !defined(MIJIN_IO_STLSTREAM_HPP_INCLUDED)