From 305c263afbbaf06e545b05afa31cc345d1209a63 Mon Sep 17 00:00:00 2001
From: Francois Best <francoisbest@gmail.com>
Date: Mon, 10 Oct 2016 16:57:56 +0200
Subject: [PATCH] Added RingBuffer utility class for USB transport.

---
 src/midi_RingBuffer.h   | 63 +++++++++++++++++++++++++++
 src/midi_RingBuffer.hpp | 94 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 157 insertions(+)
 create mode 100644 src/midi_RingBuffer.h
 create mode 100644 src/midi_RingBuffer.hpp

diff --git a/src/midi_RingBuffer.h b/src/midi_RingBuffer.h
new file mode 100644
index 0000000..ea6884a
--- /dev/null
+++ b/src/midi_RingBuffer.h
@@ -0,0 +1,63 @@
+/*!
+ *  @file       midi_RingBuffer.h
+ *  Project     Arduino MIDI Library
+ *  @brief      MIDI Library for Arduino - Ring Buffer
+ *  @version    4.2
+ *  @author     Francois Best
+ *  @date       10/10/2016
+ *  @license    MIT - Copyright (c) 2016 Francois Best
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once
+
+#include "midi_Namespace.h"
+
+BEGIN_MIDI_NAMESPACE
+
+template<typename DataType, int Size>
+class RingBuffer
+{
+public:
+     RingBuffer();
+    ~RingBuffer();
+
+public:
+    int getLength() const;
+    bool isEmpty() const;
+
+public:
+    void write(DataType inData);
+    void write(const DataType* inData, int inSize);
+    void clear();
+
+public:
+    DataType read();
+    void read(DataType* outData, int inSize);
+
+private:
+    DataType mData[Size];
+    DataType* mWriteHead;
+    DataType* mReadHead;
+};
+
+END_MIDI_NAMESPACE
+
+#include "midi_RingBuffer.hpp"
diff --git a/src/midi_RingBuffer.hpp b/src/midi_RingBuffer.hpp
new file mode 100644
index 0000000..b3e073e
--- /dev/null
+++ b/src/midi_RingBuffer.hpp
@@ -0,0 +1,94 @@
+#pragma once
+
+BEGIN_MIDI_NAMESPACE
+
+template<typename DataType, int Size>
+RingBuffer<DataType, Size>::RingBuffer()
+    : mWriteHead(mData)
+    , mReadHead(mData)
+{
+    memset(mData, DataType(0), Size * sizeof(DataType));
+}
+
+template<typename DataType, int Size>
+RingBuffer<DataType, Size>::~RingBuffer()
+{
+}
+
+// -----------------------------------------------------------------------------
+
+template<typename DataType, int Size>
+int RingBuffer<DataType, Size>::getLength() const
+{
+    if (mReadHead == mWriteHead)
+    {
+        return 0;
+    }
+    else if (mWriteHead > mReadHead)
+    {
+        return int(mWriteHead - mReadHead);
+    }
+    else
+    {
+        return int(mWriteHead - mData) + Size - int(mReadHead - mData);
+    }
+}
+
+template<typename DataType, int Size>
+bool RingBuffer<DataType, Size>::isEmpty() const
+{
+    return mReadHead == mWriteHead;
+}
+
+// -----------------------------------------------------------------------------
+
+template<typename DataType, int Size>
+void RingBuffer<DataType, Size>::write(DataType inData)
+{
+    *mWriteHead++ = inData;
+    if (mWriteHead >= mData + Size)
+    {
+        mWriteHead = mData;
+    }
+}
+
+template<typename DataType, int Size>
+void RingBuffer<DataType, Size>::write(const DataType* inData, int inSize)
+{
+    for (int i = 0; i < inSize; ++i)
+    {
+        write(inData[i]);
+    }
+}
+
+template<typename DataType, int Size>
+void RingBuffer<DataType, Size>::clear()
+{
+    memset(mData, DataType(0), Size * sizeof(DataType));
+    mReadHead  = mData;
+    mWriteHead = mData;
+}
+
+// -----------------------------------------------------------------------------
+
+template<typename DataType, int Size>
+DataType RingBuffer<DataType, Size>::read()
+{
+    const DataType data = *mReadHead++;
+    if (mReadHead >= mData + Size)
+    {
+        mReadHead = mData;
+    }
+    return data;
+}
+
+template<typename DataType, int Size>
+void RingBuffer<DataType, Size>::read(DataType* outData, int inSize)
+{
+    for (int i = 0; i < inSize; ++i)
+    {
+        outData[i] = read();
+    }
+}
+
+END_MIDI_NAMESPACE