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include/sp/common/DataBuffer.h

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+#pragma once
+
+/**
+ * \file DataBuffer.h
+ * \brief File containing the sp::DataBuffer class
+ */
+
+#include <algorithm>
+#include <array>
+#include <cassert>
+#include <cstdint>
+#include <cstring>
+#include <string>
+#include <sp/common/VarInt.h>
+#include <vector>
+
+namespace sp {
+
+/**
+ * \class DataBuffer
+ * \brief Class used to manipulate memory
+ */
+class DataBuffer {
+  private:
+	typedef std::vector<std::uint8_t> Data;
+	Data m_Buffer;
+	std::size_t m_ReadOffset;
+
+  public:
+	typedef Data::iterator iterator;
+	typedef Data::const_iterator const_iterator;
+	typedef Data::reference reference;
+	typedef Data::const_reference const_reference;
+	typedef Data::difference_type difference_type;
+
+	DataBuffer();
+	DataBuffer(const DataBuffer& other);
+	DataBuffer(const DataBuffer& other, difference_type offset);
+	DataBuffer(DataBuffer&& other);
+	DataBuffer(const std::string& str);
+
+	DataBuffer& operator=(const DataBuffer& other);
+	DataBuffer& operator=(DataBuffer&& other);
+
+	/**
+	 * \brief Append data to the buffer
+	 */
+	template <typename T>
+	void Append(const T& data) {
+		std::size_t size = sizeof(data);
+		std::size_t end_pos = m_Buffer.size();
+		m_Buffer.resize(m_Buffer.size() + size);
+		std::memcpy(&m_Buffer[end_pos], &data, size);
+	}
+
+	/**
+	 * \brief Append data to the buffer
+	 */
+	template <typename T>
+	DataBuffer& operator<<(const T& data) {
+		Append(data);
+		return *this;
+	}
+
+	/**
+	 * \brief Append a string to the buffer
+	 * \warning Don't use it for binary data !
+	 * \param str The string to append
+	 */
+	DataBuffer& operator<<(const std::string& str);
+
+	/**
+	 * \brief Append data to the buffer from another const buffer
+	 * \param data The buffer to append
+	 */
+	DataBuffer& operator<<(const DataBuffer& data);
+
+	/**
+	 * \brief Append a vector to the buffer by first writing the size
+	 * \param data The vector to append
+	 */
+	template <typename T>
+	DataBuffer& operator<<(const std::vector<T>& data) {
+		*this << VarInt{data.size()};
+		for (const auto& element : data) {
+			*this << element;
+		}
+		return *this;
+	}
+
+	/**
+	 * \brief Append an array to the buffer by first writing the size
+	 * \param data The buffer to append
+	 */
+	template <typename T, std::size_t Size>
+	DataBuffer& operator<<(const std::array<T, Size>& data) {
+		for (const auto& element : data) {
+			*this << element;
+		}
+		return *this;
+	}
+
+	/**
+	 * \brief Read some data from the buffer and assign to desired variable
+	 */
+	template <typename T>
+	DataBuffer& operator>>(T& data) {
+		assert(m_ReadOffset + sizeof(T) <= GetSize());
+		data = *(reinterpret_cast<T*>(&m_Buffer[m_ReadOffset]));
+		m_ReadOffset += sizeof(T);
+		return *this;
+	}
+
+	/**
+	 * \brief Read some data from the buffer and assign to the new buffer
+	 * \param data The buffer to assign
+	 */
+	DataBuffer& operator>>(DataBuffer& data);
+
+	/**
+	 * \brief Read a string from the buffer
+	 * \param str The string to assign in the new buffer
+	 * \warning Don't use it for binary data !
+	 */
+	DataBuffer& operator>>(std::string& str);
+
+	/**
+	 * \brief Read a vector (size + data) from the buffer
+	 * \pre The vector is assumed to be empty
+	 */
+	template <typename T>
+	DataBuffer& operator>>(std::vector<T>& data) {
+		VarInt arraySize;
+		*this >> arraySize;
+		for (std::size_t i = 0; i < arraySize.GetValue(); i++) {
+			T newElement;
+			*this >> newElement;
+			data.push_back(newElement);
+		}
+		return *this;
+	}
+
+	/**
+	 * \brief Read an array from the buffer
+	 */
+	template <std::size_t Size, typename T>
+	DataBuffer& operator>>(std::array<T, Size>& data) {
+		for (std::size_t i = 0; i < Size; i++) {
+			T newElement;
+			*this >> newElement;
+			data[i] = newElement;
+		}
+		return *this;
+	}
+
+	/**
+	 * \brief Write some data to the buffer
+	 * \param buffer The buffer to write
+	 * \param amount The amount of data to write
+	 */
+	void WriteSome(const char* buffer, std::size_t amount);
+
+	/**
+	 * \brief Write some data to the buffer
+	 * \param buffer The buffer to write
+	 * \param amount The amount of data to write
+	 */
+	void WriteSome(const std::uint8_t* buffer, std::size_t amount);
+
+	/**
+	 * \brief Read some data from the buffer
+	 * \param buffer The buffer to Read
+	 * \param amount The amount of data from the buffer
+	 */
+	void ReadSome(char* buffer, std::size_t amount);
+
+	/**
+	 * \brief Read some data from the buffer
+	 * \param buffer The buffer to Read
+	 * \param amount The amount of data from the buffer
+	 */
+	void ReadSome(std::uint8_t* buffer, std::size_t amount);
+
+	/**
+	 * \brief Read some data from the buffer
+	 * \param buffer The buffer to Read
+	 * \param amount The amount of data from the buffer
+	 */
+	void ReadSome(DataBuffer& buffer, std::size_t amount);
+
+	/**
+	 * \brief Resize the buffer
+	 * \param size The new size of the buffer
+	 */
+	void Resize(std::size_t size) {
+		m_Buffer.resize(size);
+	}
+
+	/**
+	 * \brief Reserve some space in the buffer
+	 * \param amount The amount of space to reserve
+	 */
+	void Reserve(std::size_t amount) {
+		m_Buffer.reserve(amount);
+	}
+
+
+	/**
+	 * \brief Clear the buffer
+	 */
+	void Clear() {
+		m_Buffer.clear();
+		m_ReadOffset = 0;
+	}
+
+	/**
+	 * \brief When the buffer has been read entirely
+	 */
+	bool IsFinished() const {
+		return m_ReadOffset >= m_Buffer.size();
+	}
+
+	/**
+	 * \brief Get the buffer data
+	 */
+	std::uint8_t* data() {
+		return m_Buffer.data();
+	}
+
+	/**
+	 * \brief Get the buffer data
+	 */
+	const std::uint8_t* data() const {
+		return m_Buffer.data();
+	}
+
+	/**
+	 * \brief Get the read offset
+	 */
+	std::size_t GetReadOffset() const {
+		return m_ReadOffset;
+	}
+
+	/**
+	 * \brief Set the read offset
+	 * \param pos The new read offset
+	 */
+	void SetReadOffset(std::size_t pos);
+
+	/**
+	 * \brief Get the size of the buffer
+	 */
+	std::size_t GetSize() const;
+
+	/**
+	 * \brief Get the remaining size of the buffer
+	 */
+	std::size_t GetRemaining() const;
+
+	/**
+	 * \brief Read a file into the buffer
+	 * \param fileName The name of the file to read
+	 */
+	bool ReadFile(const std::string& fileName);
+
+	/**
+	 * \brief Write a file into the buffer
+	 * \param fileName The name of the file to write to
+	 */
+	bool WriteFile(const std::string& fileName) const;
+
+	/**
+	 * \brief Allocate the buffer on the heap
+	 * \warning Don't forget to free the data !
+	 */
+	std::uint8_t* HeapAllocatedData() const {
+		std::uint8_t* newBuffer = new std::uint8_t[GetSize()];
+		std::memcpy(newBuffer, data(), GetSize());
+		return newBuffer;
+	}
+
+	/**
+	 * \brief Operator == to compare two DataBuffer
+	 */
+	bool operator==(const DataBuffer& other) const {
+		return m_Buffer == other.m_Buffer;
+	}
+
+	iterator begin();
+	iterator end();
+	const_iterator begin() const;
+	const_iterator end() const;
+};
+
+/**
+ * \brief Operator << to write a DataBuffer to an ostream
+ */
+std::ostream& operator<<(std::ostream& os, const DataBuffer& buffer);
+
+}  // namespace sp