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xn65/includes/xna/csharp/stream.hpp
2024-11-09 19:15:55 -03:00

206 lines
7.0 KiB
C++

#ifndef XNA_CSHARP_STREAM_HPP
#define XNA_CSHARP_STREAM_HPP
#include <fstream>
#include <string>
#include <vector>
#include <cstdint>
#include "../exception.hpp"
namespace xna {
// Provides seek reference points.
// To seek to the end of a stream, call stream.Seek(0, SeekOrigin.End).
enum class SeekOrigin {
Begin,
Current,
End,
};
// Contains constants for specifying how the OS should open a file.
// These will control whether you overwrite a file, open an existing
// file, or some combination thereof.
//
// To append to a file, use Append (which maps to OpenOrCreate then we seek
// to the end of the file). To truncate a file or create it if it doesn't
// exist, use Create.
enum class FileMode {
// Creates a new file. An exception is raised if the file already exists.
CreateNew,
// Creates a new file. If the file already exists, it is overwritten.
Create,
// Opens an existing file. An exception is raised if the file does not exist.
Open,
// Opens the file if it exists. Otherwise, creates a new file.
OpenOrCreate,
// Opens an existing file. Once opened, the file is truncated so that its
// size is zero bytes. The calling process must open the file with at least
// WRITE access. An exception is raised if the file does not exist.
Truncate,
// Opens the file if it exists and seeks to the end. Otherwise,
// creates a new file.
Append,
};
//A simplified port of the System.IO.Stream.
//Provides a generic view of a sequence of bytes. This is an abstract class.
class Stream {
public:
virtual ~Stream(){}
//When overridden in a derived class, gets a value indicating whether the current stream supports reading.
virtual bool CanRead() { return true; }
//When overridden in a derived class, gets a value indicating whether the current stream supports writing.
virtual bool CanWrite() { return true; }
//When overridden in a derived class, gets a value indicating whether the current stream supports seeking.
virtual bool CanSeek() { return true; }
//Gets a value that determines whether the current stream can time out.
virtual bool CanTimeout() { return false; }
//Gets the length in bytes of the stream.
virtual int64_t Length() = 0;
//Gets or sets the position within the current stream.
virtual int64_t Position() = 0;
//Gets or sets the position within the current stream.
virtual void Position(int64_t value) { Seek(value, SeekOrigin::Begin); }
//When overridden in a derived class, sets the length of the current stream.
virtual void SetLength(int64_t value) = 0;
//Closes the current stream and releases any resources
virtual void Close() = 0;
//Sets the position within the current stream.
virtual int64_t Seek(int64_t offset, SeekOrigin const& origin) = 0;
//Reads a sequence of bytes from the current stream and advances the position within the stream by the number of bytes read.
virtual int32_t Read(uint8_t* buffer, int32_t bufferLength, int32_t offset, int32_t count) = 0;
//Reads a sequence of bytes from the current stream and advances the position within the stream by the number of bytes read.
virtual int32_t Read(std::vector<uint8_t>& buffer, int32_t offset, int32_t count) = 0;
//Reads a byte from the stream and advances the position within the stream by one byte, or returns -1 if at the end of the stream.
virtual int32_t ReadByte() = 0;
//Writes a sequence of bytes to the current stream and advances the current position within this stream by the number of bytes written.
virtual void Write(uint8_t const* buffer, int32_t bufferLength, int32_t offset, int32_t count) = 0;
//Writes a sequence of bytes to the current stream and advances the current position within this stream by the number of bytes written.
virtual void Write(std::vector<uint8_t> const& buffer, int32_t offset, int32_t count) = 0;
//Writes a byte to the current position in the stream and advances the position within the stream by one byte.
virtual void WriteByte(uint8_t value) = 0;
};
//A simplified port of the System.IO.MemoryStream.
class MemoryStream : public Stream {
public:
constexpr MemoryStream(){}
constexpr MemoryStream(std::vector<uint8_t> const& bytes):
_buffer(bytes),
_length(static_cast<int64_t>(bytes.size())){}
~MemoryStream() override {
Close();
}
constexpr MemoryStream(int32_t capacity) :
_buffer(static_cast<size_t>(capacity)),
_length(capacity > 0 ? capacity : 0){}
virtual constexpr int64_t Length() override {
if (_closed)
return 0;
return _length;
}
virtual constexpr void SetLength(int64_t value) override {
_buffer.reserve(value);
_length = value;
}
virtual constexpr int64_t Position() override {
if (_closed)
return 0;
return _position;
}
virtual constexpr void Close() override {
_closed = true;
_buffer = std::vector<uint8_t>();
}
virtual int64_t Seek(int64_t offset, SeekOrigin const& origin) override;
virtual int32_t Read(uint8_t* buffer, int32_t bufferLength, int32_t offset, int32_t count) override;
virtual int32_t Read(std::vector<uint8_t>& buffer, int32_t offset, int32_t count) override;
virtual int32_t ReadByte() override;
virtual void Write(uint8_t const* buffer, int32_t bufferLength, int32_t offset, int32_t count) override;
virtual void Write(std::vector<uint8_t> const& buffer, int32_t offset, int32_t count) override;
virtual void WriteByte(uint8_t value) override;
public:
std::vector<uint8_t> _buffer;
private:
int32_t _position{ 0 };
int32_t _origin{ 0 };
int64_t _length{ 0 };
bool _closed{ false };
};
//A simplified port of the System.IO.FileStream.
class FileStream : public Stream {
public:
FileStream(std::string const& path, FileMode fileMode);
FileStream(std::string const& path);
~FileStream() override {
Close();
}
virtual int64_t Length() override;
virtual int64_t Position() override;
virtual void SetLength(int64_t value) override {
Exception::Throw(Exception::NOT_IMPLEMENTED);
}
inline virtual void Close() override {
_closed = true;
if(_fstream.is_open())
_fstream.close();
}
virtual int64_t Seek(int64_t offset, SeekOrigin const& origin) override;
virtual int32_t Read(uint8_t* buffer, int32_t bufferLength, int32_t offset, int32_t count) override;
virtual int32_t Read(std::vector<uint8_t>& buffer, int32_t offset, int32_t count) override;
virtual int32_t ReadByte() override;
virtual void Write(uint8_t const* buffer, int32_t bufferLength, int32_t offset, int32_t count) override;
virtual void Write(std::vector<uint8_t> const& buffer, int32_t offset, int32_t count) override;
virtual void WriteByte(uint8_t value) override;
public:
std::fstream _fstream;
private:
std::streampos _filesize{ 0 };
bool _closed{ false };
bool _truncated{ false };
int64_t endOfFile() {
if (_closed)
return 0;
const auto pos = _fstream.tellg();
_fstream.seekg(0, std::ios_base::end);
const auto end = _fstream.tellg();
_fstream.seekg(pos);
return static_cast<int64_t>(end);
}
};
}
#endif