#1 - quicr module

modules/io/include/bytebuffer/ByteBufferWriter.hpp

@@ -0,0 +1,64 @@
+#pragma once
+
+#include <cstring>
+#include <span>
+#include <spdlog/spdlog.h>
+
+namespace tw::net {
+
+/**
+ * Circular byte buffer.
+ */
+class ByteBufferWriter {
+public:
+    ByteBufferWriter(std::span<std::byte> target) : buffer(target) {}
+
+    template<typename T>
+    size_t write_bytes(const T *data) {
+        return write_bytes((void*)data, sizeof(T));
+    }
+
+    size_t write_bytes(void* data, size_t size) {
+        return write_bytes(std::span<const std::byte>{(std::byte*)data, (std::byte*)data + size});
+    }
+
+    size_t write_bytes(std::span<const std::byte> data) {
+        if(remaining() < data.size()) {
+            return 0;
+        }
+
+        if(writeOffset + data.size() <= buffer.size()) {
+            std::memcpy(buffer.data() + writeOffset, data.data(), data.size());
+            writeOffset += data.size();
+        } else {
+            size_t firstPart = buffer.size() - writeOffset;
+            std::memcpy(buffer.data() + writeOffset, data.data(), firstPart);
+            std::memcpy(buffer.data(), data.data() + firstPart, data.size() - firstPart);
+            writeOffset = (writeOffset + data.size()) % buffer.size();
+        }
+
+        return data.size();
+    }
+
+    constexpr size_t length() const {
+        return writeOffset;
+    }
+
+    size_t remaining() const {
+        return buffer.size() - writeOffset;
+    }
+
+    void reset() {
+        writeOffset = 0;
+    }
+
+    void skip_write(size_t bytes) {
+        writeOffset = (writeOffset + std::min(bytes, remaining()));
+    }
+
+private:
+    std::span<std::byte> buffer;
+    size_t writeOffset = 0;
+};
+
+} // namespace tw::net