1 files changed, 195 insertions, 0 deletions
diff --git a/src/core/buffer.h b/src/core/buffer.h
new file mode 100644
index 0000000..4485ff1
--- /dev/null
+++ b/src/core/buffer.h
@@ -0,0 +1,195 @@
+#pragma once
+
+#include "error.h"
+
+#include <array>
+#include <cstdint>
+#include <deque>
+#include <list>
+#include <string>
+#include <vector>
+
+namespace saw {
+/*
+ * Access class to reduce templated BufferSegments bloat
+ */
+class buffer {
+protected:
+	~buffer() = default;
+
+public:
+	virtual size_t read_position() const = 0;
+	virtual size_t read_composite_length() const = 0;
+	virtual size_t read_segment_length(size_t offset = 0) const = 0;
+	virtual void read_advance(size_t bytes) = 0;
+
+	virtual uint8_t &read(size_t i = 0) = 0;
+	virtual const uint8_t &read(size_t i = 0) const = 0;
+
+	virtual size_t write_position() const = 0;
+	virtual size_t write_composite_length() const = 0;
+	virtual size_t write_segment_length(size_t offset = 0) const = 0;
+	virtual void write_advance(size_t bytes) = 0;
+
+	virtual uint8_t &write(size_t i = 0) = 0;
+	virtual const uint8_t &write(size_t i = 0) const = 0;
+
+	/*
+	 * Sometime buffers need to grow with a little more control
+	 * than with push and pop for more efficient calls.
+	 * There is nothing you can do if read hasn't been filled, but at
+	 * least write can be increased if it is demanded.
+	 */
+	virtual error write_require_length(size_t bytes) = 0;
+
+	error push(const uint8_t &value);
+	error push(const uint8_t &buffer, size_t size);
+	error pop(uint8_t &value);
+	error pop(uint8_t &buffer, size_t size);
+
+	/*
+	 * Subject to change
+	 */
+	std::string to_string() const;
+	std::string to_hex() const;
+};
+
+/*
+ *	A viewer class for buffers.
+ *	Working on the reference buffer invalidates the buffer view
+ */
+class buffer_view : public buffer {
+private:
+	buffer &buffer_;
+	size_t read_offset_;
+	size_t write_offset_;
+
+public:
+	buffer_view(buffer &);
+
+	size_t read_position() const override;
+	size_t read_composite_length() const override;
+	size_t read_segment_length(size_t offset = 0) const override;
+	void read_advance(size_t bytes) override;
+
+	uint8_t &read(size_t i = 0) override;
+	const uint8_t &read(size_t i = 0) const override;
+
+	size_t write_position() const override;
+	size_t write_composite_length() const override;
+	size_t write_segment_length(size_t offset = 0) const override;
+	void write_advance(size_t bytes) override;
+
+	uint8_t &write(size_t i = 0) override;
+	const uint8_t &write(size_t i = 0) const override;
+
+	error write_require_length(size_t bytes) override;
+
+	size_t read_offset() const;
+	size_t write_offset() const;
+};
+
+/*
+ * Buffer size meant for default allocation size of the ringbuffer since
+ * this class currently doesn't support proper resizing
+ */
+constexpr size_t RING_BUFFER_MAX_SIZE = 4096;
+/*
+ * Buffer wrapping around if read caught up
+ */
+class ring_buffer final : public buffer {
+private:
+	std::vector<uint8_t> buffer_;
+	size_t read_position_;
+	size_t write_position_;
+	bool write_reached_read_ = false;
+
+public:
+	ring_buffer();
+	ring_buffer(size_t size);
+
+	inline size_t size() const { return buffer_.size(); }
+
+	inline uint8_t &operator[](size_t i) { return buffer_[i]; }
+	inline const uint8_t &operator[](size_t i) const { return buffer_[i]; }
+
+	size_t read_position() const override;
+	size_t read_composite_length() const override;
+	size_t read_segment_length(size_t offset = 0) const override;
+	void read_advance(size_t bytes) override;
+
+	uint8_t &read(size_t i = 0) override;
+	const uint8_t &read(size_t i = 0) const override;
+
+	size_t write_position() const override;
+	size_t write_composite_length() const override;
+	size_t write_segment_length(size_t offset = 0) const override;
+	void write_advance(size_t bytes) override;
+
+	uint8_t &write(size_t i = 0) override;
+	const uint8_t &write(size_t i = 0) const override;
+
+	error write_require_length(size_t bytes) override;
+};
+
+/*
+ * One time buffer
+ */
+class array_buffer : public buffer {
+private:
+	std::vector<uint8_t> buffer_;
+
+	size_t read_position_;
+	size_t write_position_;
+
+public:
+	array_buffer(size_t size);
+
+	size_t read_position() const override;
+	size_t read_composite_length() const override;
+	size_t read_segment_length(size_t offset = 0) const override;
+	void read_advance(size_t bytes) override;
+
+	uint8_t &read(size_t i = 0) override;
+	const uint8_t &read(size_t i = 0) const override;
+
+	size_t write_position() const override;
+	size_t write_composite_length() const override;
+	size_t write_segment_length(size_t offset = 0) const override;
+	void write_advance(size_t bytes) override;
+
+	uint8_t &write(size_t i = 0) override;
+	const uint8_t &write(size_t i = 0) const override;
+
+	error write_require_length(size_t bytes) override;
+};
+
+class chain_array_buffer : public buffer {
+private:
+	std::deque<array_buffer> buffer_;
+
+	size_t read_position_;
+	size_t write_position_;
+
+public:
+	chain_array_buffer();
+
+	size_t read_position() const override;
+	size_t read_composite_length() const override;
+	size_t read_segment_length(size_t offset = 0) const override;
+	void read_advance(size_t bytes) override;
+
+	uint8_t &read(size_t i = 0) override;
+	const uint8_t &read(size_t i = 0) const override;
+
+	size_t write_position() const override;
+	size_t write_composite_length() const override;
+	size_t write_segment_length(size_t offset = 0) const override;
+	void write_advance(size_t bytes) override;
+
+	uint8_t &write(size_t i = 0) override;
+	const uint8_t &write(size_t i = 0) const override;
+
+	error write_require_length(size_t bytes) override;
+};
+} // namespace saw