athena/include/Athena/MemoryWriter.hpp

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#ifndef MEMORYWRITER_HPP
#define MEMORYWRITER_HPP
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#include "Athena/IStreamWriter.hpp"
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#include <string>
#include <functional>
namespace Athena
{
namespace io
{
/*! \class MemoryWriter
* \brief A Stream class for writing data to a memory position
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*
* A Class for writing binary data to a file or memory stream,
* all work is done using a memory buffer, and not written directly to the disk
* this allows for fast, flexible code as well as the ability to quickly modify data
* \sa Stream
*/
class MemoryWriter : public IStreamWriter
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{
public:
/*! \brief This constructor references an existing buffer to write to in-place.
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*
* \param data The existing buffer
* \param length The length of the existing buffer
*/
explicit MemoryWriter(atUint8* data, atUint64 length);
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/*! \brief Sets the buffers position relative to the specified position.<br />
* It seeks relative to the current position by default.
* \param position where in the buffer to seek
* \param origin The Origin to seek \sa SeekOrigin
*/
void seek(atInt64 pos, SeekOrigin origin = SeekOrigin::Current);
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/*! \brief Returns the current position in the stream.
*
* \return Int64 The current position in the stream.
*/
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inline atUint64 position() const
{return m_position;}
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/*! \brief Returns whether or not the stream is at the end.
*
* \return bool True if at end; False otherwise.
*/
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inline atUint64 length() const
{return m_length;}
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inline bool isOpen() const {return true;}
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/*! \brief Sets the buffer to the given one, deleting the current one.<br />
* <b>BEWARE:</b> As this deletes the current buffer it WILL cause a loss of data
* if that was not the intent.<br />
* Once you pass the data to setData <b>DO NOT</b> delete the buffer
* as Stream now owns the address, this is done to keep memory usage down.
* \param data The new buffer.
* \param length The length of the new buffer.
* \throw IOException
*/
void setData(atUint8* data, atUint64 length);
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/*! \brief Returns a copy of the current buffer.<br />
* Changes to the copy do not affect the buffer so it's perfectly safe to
* directly edit the buffer and use setData to set the new information.<br />
* However once you pass the data to setData <b>DO NOT</b> delete the buffer
* as Stream now owns the address, this is done to keep memory usage down.
* \return Uint8* The copy of the buffer.
*/
atUint8* data() const;
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/*! \brief Sets the target file
*
* \param filepath The path to write to.
*/
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inline void setFilepath(const std::string& filepath)
{m_filepath = filepath;}
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/*! \brief
* Returns the target file
*/
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inline std::string filepath() const
{return m_filepath;}
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/*! \brief Saves the file to the specified file.
*
* \param filename If not empty, the filename to save to
*/
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void save(const std::string& filename = "");
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/*! \brief Writes the given buffer with the specified length, buffers can be bigger than the length
* however it's undefined behavior to try and write a buffer which is smaller than the given length.
*
* \param data The buffer to write
* \param length The amount to write
*/
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void writeUBytes(const atUint8* data, atUint64 len);
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protected:
MemoryWriter() {}
atUint8* m_data;
atUint64 m_length;
atUint64 m_position;
std::string m_filepath; //!< Path to the target file
};
class MemoryCopyWriter : public MemoryWriter
{
public:
/*! \brief This constructor copies an existing buffer to write to.
*
* \param data The existing buffer
* \param length The length of the existing buffer
*/
explicit MemoryCopyWriter(atUint8* data=nullptr, atUint64 length=0x10);
/*! \brief This constructor creates an instance from a file on disk.
*
* \param filename The file to create the stream from
*/
MemoryCopyWriter(const std::string& filename);
/*! \brief Sets the buffers position relative to the specified position.<br />
* It seeks relative to the current position by default.
* \param position where in the buffer to seek
* \param origin The Origin to seek \sa SeekOrigin
*/
void seek(atInt64 pos, SeekOrigin origin = SeekOrigin::Current);
/*! \brief Sets the buffer to the given one, deleting the current one.<br />
* <b>BEWARE:</b> As this deletes the current buffer it WILL cause a loss of data
* if that was not the intent.<br />
* Once you pass the data to setData <b>DO NOT</b> delete the buffer
* as Stream now owns the address, this is done to keep memory usage down.
* \param data The new buffer.
* \param length The length of the new buffer.
* \throw IOException
*/
void setData(const atUint8* data, atUint64 length);
/*! \brief Writes the given buffer with the specified length, buffers can be bigger than the length
* however it's undefined behavior to try and write a buffer which is smaller than the given length.
*
* \param data The buffer to write
* \param length The amount to write
*/
void writeUBytes(const atUint8* data, atUint64 len);
protected:
std::unique_ptr<atUint8[]> m_dataCopy;
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private:
void resize(atUint64 newSize);
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};
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}
}
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#ifndef MEMORYWRITER_BASE
#define MEMORYWRITER_BASE() \
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private: \
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typedef Athena::io::MemoryWriter base
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#endif // BINARYWRITER_BASE
#ifndef MEMORYCOPYWRITER_BASE
#define MEMORYCOPYWRITER_BASE() \
private: \
typedef Athena::io::MemoryCopyWriter base
#endif // BINARYWRITER_BASE
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#endif // MEMORYWRITER_HPP