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+/*
+ * Copyright (C) 2003-2014 Max Kellermann <max@duempel.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef STATIC_FIFO_BUFFER_HPP
+#define STATIC_FIFO_BUFFER_HPP
+
+#include "WritableBuffer.hxx"
+
+#include <utility>
+#include <algorithm>
+
+#include <assert.h>
+#include <stddef.h>
+
+/**
+ * A first-in-first-out buffer: you can append data at the end, and
+ * read data from the beginning.  This class automatically shifts the
+ * buffer as needed.  It is not thread safe.
+ */
+template<class T, size_t size>
+class StaticFifoBuffer {
+public:
+	typedef size_t size_type;
+
+public:
+	typedef WritableBuffer<T> Range;
+
+protected:
+	size_type head, tail;
+	T data[size];
+
+public:
+	constexpr
+	StaticFifoBuffer():head(0), tail(0) {}
+
+	void Shift() {
+		if (head == 0)
+			return;
+
+		assert(head <= size);
+		assert(tail <= size);
+		assert(tail >= head);
+
+		std::move(data + head, data + tail, data);
+
+		tail -= head;
+		head = 0;
+	}
+
+	void Clear() {
+		head = tail = 0;
+	}
+
+	bool IsEmpty() const {
+		return head == tail;
+	}
+
+	bool IsFull() const {
+		return head == 0 && tail == size;
+	}
+
+	/**
+	 * Prepares writing.  Returns a buffer range which may be written.
+	 * When you are finished, call append().
+	 */
+	Range Write() {
+		if (IsEmpty())
+			Clear();
+		else if (tail == size)
+			Shift();
+
+		return Range(data + tail, size - tail);
+	}
+
+	/**
+	 * Expands the tail of the buffer, after data has been written to
+	 * the buffer returned by write().
+	 */
+	void Append(size_type n) {
+		assert(tail <= size);
+		assert(n <= size);
+		assert(tail + n <= size);
+
+		tail += n;
+	}
+
+	/**
+	 * Return a buffer range which may be read.  The buffer pointer is
+	 * writable, to allow modifications while parsing.
+	 */
+	Range Read() {
+		return Range(data + head, tail - head);
+	}
+
+	/**
+	 * Marks a chunk as consumed.
+	 */
+	void Consume(size_type n) {
+		assert(tail <= size);
+		assert(head <= tail);
+		assert(n <= tail);
+		assert(head + n <= tail);
+
+		head += n;
+	}
+};
+
+#endif