mirror of https://github.com/libAthena/athena.git
138 lines
4.3 KiB
C++
138 lines
4.3 KiB
C++
#ifndef MEMORYREADER_HPP
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#define MEMORYREADER_HPP
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#include <string>
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#include <memory>
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#include <functional>
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#include "Athena/IStreamReader.hpp"
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namespace Athena
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{
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namespace io
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{
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/*! \class MemoryReader
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* \brief A Stream class for reading data from a memory position
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*
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* A Class for reading binary data from a file or memory stream,
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* all work is done using a memory buffer, and not read directly from the disk
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* this allows for fast, flexible code as well as the ability to quickly modify data
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* \sa Stream
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*/
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class MemoryReader : public IStreamReader
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{
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protected:
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MemoryReader() = default;
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public:
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virtual ~MemoryReader();
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/*! \brief This constructor references an existing buffer to read from.
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*
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* \param data The existing buffer
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* \param length The length of the existing buffer
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* \param takeOwnership Memory will be freed with the reader if set
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*/
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MemoryReader(const atUint8* data, atUint64 length, bool takeOwnership=false);
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/*! \brief Sets the buffers position relative to the specified position.<br />
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* It seeks relative to the current position by default.
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* \param position where in the buffer to seek
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* \param origin The Origin to seek \sa SeekOrigin
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*/
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void seek(atInt64 pos, SeekOrigin origin = SeekOrigin::Current);
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/*! \brief Returns the current position in the stream.
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*
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* \return Int64 The current position in the stream.
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*/
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inline atUint64 position() const
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{return m_position;}
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/*! \brief Returns whether or not the stream is at the end.
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*
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* \return bool True if at end; False otherwise.
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*/
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inline atUint64 length() const
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{return m_length;}
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/*! \brief Sets the buffer to the given one, deleting the current one.<br />
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* <b>BEWARE:</b> As this deletes the current buffer it WILL cause a loss of data
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* if that was not the intent.<br />
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* Once you pass the data to setData <b>DO NOT</b> delete the buffer
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* as Stream now owns the address, this is done to keep memory usage down.
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* \param data The new buffer.
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* \param length The length of the new buffer.
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* \param takeOwnership Memory will be freed with the reader if set
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* \throw IOException
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*/
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void setData(const atUint8* data, atUint64 length, bool takeOwnership=false);
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/*! \brief Returns a copy of the current buffer.<br />
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* Changes to the copy do not affect the buffer so it's perfectly safe to
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* directly edit the buffer and use setData to set the new information.<br />
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* However once you pass the data to setData <b>DO NOT</b> delete the buffer
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* as Stream now owns the address, this is done to keep memory usage down.
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* \return Uint8* The copy of the buffer.
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*/
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atUint8* data() const;
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/*! \brief Reads a specified number of bytes to user-allocated buffer
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* \param buf User-allocated buffer pointer
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* \param len Length to read
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* \return Number of bytes read
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*/
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atUint64 readUBytesToBuf(void* buf, atUint64 len);
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protected:
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const atUint8* m_data = nullptr;
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atUint64 m_length = 0;
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atUint64 m_position = 0;
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bool m_owns = false;
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};
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class MemoryCopyReader : public MemoryReader
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{
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public:
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/*! \brief This constructor copies an existing buffer to read from.
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*
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* \param data The existing buffer
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* \param length The length of the existing buffer
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*/
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MemoryCopyReader(const atUint8* data, atUint64 length);
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/*! \brief This constructor creates an instance from a file on disk.
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*
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* \param filename The file to create the stream from
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*/
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MemoryCopyReader(const std::string& filename)
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: m_filepath(filename)
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{loadData();}
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void setData(const atUint8* data, atUint64 length);
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protected:
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void loadData();
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std::unique_ptr<atUint8[]> m_dataCopy;
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std::string m_filepath; //!< Path to the target file
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};
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} // io
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} // Athena
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#ifndef MEMORYREADER_BASE
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#define MEMORYREADER_BASE() \
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private: \
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typedef Athena::io::MemoryReader base
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#endif // MEMORYREADER_BASE
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#ifndef MEMORYCOPYREADER_BASE
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#define MEMORYCOPYREADER_BASE() \
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private: \
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typedef Athena::io::MemoryCopyReader base
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#endif // MEMORYCOPYREADER_BASE
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#endif // MEMORYREADER_HPP
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