A stream buffer object to a chunk of memory. More...

#include <memorystream.h>

Inheritance diagram for Mezzanine::Resource::MemoryStreamBuffer:

Collaboration diagram for Mezzanine::Resource::MemoryStreamBuffer:

Public Member Functions
	MemoryStreamBuffer ()
	Class constructor.

virtual	~MemoryStreamBuffer ()
	Class destructor.

void	ConfigureBuffer (const std::streampos Pos, std::ios_base::openmode Mode=std::ios_base::in\|std::ios_base::out)
	Sets the get and put pointers for the streambuffer and assigns the current position to the specified offset. More...

void	CopyBuffer (const char *Buffer, const Whole BufferSize)
	Copies a pre-existing buffer to this buffer for streaming. More...

void	CreateBuffer (const Whole Size)
	Convenience method for creating a new buffer to be used by this stream. More...

void	DestroyBuffer ()
	Convenience method for deleting the existing buffer being streamed.

Char8 *	GetBufferEnd () const
	Gets the end of this buffer. More...

std::streamsize	GetBufferSize () const
	Gets the size of the current buffer being streamed to/from. More...

Char8 *	GetBufferStart () const
	Gets the start of this buffer. More...

Boole	GetFreeBuffer () const
	Gets if this should delete it's internal buffer when it is destroyed. More...

void	SetBuffer (char *Buffer, const Whole BufferSize, const Boole FreeBuf)
	Wraps an external buffer for streaming. More...

void	SetFreeBuffer (const Boole FreeBuf)
	Sets if this should delete it's internal buffer when it is destroyed. More...

Protected Member Functions
std::streamoff	CheckStreamOffset (const std::streamoff CursorOffset, const std::streamoff Adjust)
	Verifies an offset in this stream is valid for a read or write cursor. More...

std::streampos	CheckStreamPosition (const std::streampos Position)
	Verifies a position in this stream is valid. More...

std::streampos	GetReadPosition () const
	Gets the current position of the read cursor. More...

std::streampos	GetWritePosition () const
	Gets the current position of the write cursor. More...

virtual void	imbue (const std::locale &loc)
	Notifies this class that a new locale is being imbued to this streambuf. More...

virtual int	overflow (int c=traits_type::eof())
	Writes a character at the current write position without advancing the write position. More...

virtual int	pbackfail (int c=traits_type::eof())
	Reverse the last character extraction operation by decrementing the read position and placing the specified character in it's place. More...

virtual std::streampos	seekoff (std::streamoff off, std::ios_base::seekdir way, std::ios_base::openmode which=std::ios_base::in\|std::ios_base::out)
	Moves the read and/or write pointers in the stream. More...

virtual std::streampos	seekpos (std::streampos sp, std::ios_base::openmode which=std::ios_base::in\|std::ios_base::out)
	Moves the read and/or write pointers to the specified position in the stream. More...

virtual std::streambuf *	setbuf (char *s, std::streamsize n)
	Sets the buffer to be streamed from. More...

virtual std::streamsize	showmanyc ()
	Gets the number of characters remaining that can be safely extracted from this buffer. More...

virtual int	sync ()
	Syncs this stream buffer with it's source. More...

virtual int	uflow ()
	Gets the value at the current read position and then increments the read position. More...

virtual int	underflow ()
	Gets the value at the current read position without incrementing the read position. More...

virtual std::streamsize	xsgetn (char *s, std::streamsize n)
	Gets a number of characters starting at the read position and populates an array with them. More...

virtual std::streamsize	xsputn (const char *s, std::streamsize n)
	Writes a number of characters from a provided buffer to the stream. More...

Protected Attributes
Char8 *	BufferEnd
	A pointer to one passed the last element in the range of this buffer. More...

Char8 *	BufferStart
	A pointer to the start of this memory buffer. More...

Boole	FreeBuffer
	Stores whether or not the memory allocated will be free'd when this buffer is deleted. More...

Whole	OpenMode
	A bitfield describing the settings this buffer was opened with. More...

Detailed Description

A stream buffer object to a chunk of memory.

Definition at line 56 of file memorystream.h.

Member Function Documentation

std::streamoff Mezzanine::Resource::MemoryStreamBuffer::CheckStreamOffset	(	const std::streamoff	CursorOffset,
		const std::streamoff	Adjust
	)

protected

Verifies an offset in this stream is valid for a read or write cursor.

Parameters

CursorOffset	The current read/write position in this stream.
Adjust	The amount of offset to be checked/applied to the provided read/write position.

Returns: Returns an std::streamoff containing the clamped offset for the given cursor in this stream.

Definition at line 81 of file memorystream.cpp.

std::streampos Mezzanine::Resource::MemoryStreamBuffer::CheckStreamPosition ( const std::streampos Position )

protected

Verifies a position in this stream is valid.

Parameters

Position The position in this stream to check.

Returns: Returns an std::streampos containing the clamped position for this stream.

Definition at line 69 of file memorystream.cpp.

void Mezzanine::Resource::MemoryStreamBuffer::ConfigureBuffer	(	const std::streampos	Pos,
		std::ios_base::openmode	Mode = `std::ios_base::in \| std::ios_base::out`
	)

Sets the get and put pointers for the streambuffer and assigns the current position to the specified offset.

Parameters

Pos	The offset to set the current read/write position to.
Mode	An open mode describing if this buffer will be configured for reading, writing, or both.

Definition at line 278 of file memorystream.cpp.

void Mezzanine::Resource::MemoryStreamBuffer::CopyBuffer	(	const char *	Buffer,
		const Whole	BufferSize
	)

Copies a pre-existing buffer to this buffer for streaming.

Parameters

Buffer	The buffer to be copied.
BufferSize	The size of the buffer to be copied.

Definition at line 254 of file memorystream.cpp.

void Mezzanine::Resource::MemoryStreamBuffer::CreateBuffer ( const Whole Size )

Convenience method for creating a new buffer to be used by this stream.

Remarks: No changes will be made if the Size is set to 0 or less.

Parameters

Size	The size of the buffer to be allocated.
Mode	An open mode describing if this buffer will be configured for reading, writing, or both.

Definition at line 238 of file memorystream.cpp.

Char8 * Mezzanine::Resource::MemoryStreamBuffer::GetBufferEnd ( ) const

Gets the end of this buffer.

Returns: Returns a pointer to one passed the last valid element in this buffer.

Definition at line 267 of file memorystream.cpp.

std::streamsize Mezzanine::Resource::MemoryStreamBuffer::GetBufferSize ( ) const

Gets the size of the current buffer being streamed to/from.

Returns: Returns a std::streamsize representing the size of the current buffer, or 0 if one hasn't been initialized.

Definition at line 273 of file memorystream.cpp.

Char8 * Mezzanine::Resource::MemoryStreamBuffer::GetBufferStart ( ) const

Gets the start of this buffer.

Returns: Returns a pointer to the first valid element in this buffer.

Definition at line 261 of file memorystream.cpp.

Boole Mezzanine::Resource::MemoryStreamBuffer::GetFreeBuffer ( ) const

Gets if this should delete it's internal buffer when it is destroyed.

Returns: Returns true if the internal buffer will be deleted when this is destroyed.

Definition at line 308 of file memorystream.cpp.

std::streampos Mezzanine::Resource::MemoryStreamBuffer::GetReadPosition ( ) const

protected

Gets the current position of the read cursor.

Returns: Returns a std::streampos representing the offset of the read position from the start of the stream.

Definition at line 93 of file memorystream.cpp.

std::streampos Mezzanine::Resource::MemoryStreamBuffer::GetWritePosition ( ) const

protected

Gets the current position of the write cursor.

Returns: Returns a std::streampos representing the offset of the write position from the start of the stream.

Definition at line 96 of file memorystream.cpp.

void Mezzanine::Resource::MemoryStreamBuffer::imbue ( const std::locale & loc )

protectedvirtual

Notifies this class that a new locale is being imbued to this streambuf.

Remarks: Does nothing, implemented for ease of future coding.

Parameters

loc	The new locale being imbued.

Definition at line 102 of file memorystream.cpp.

int Mezzanine::Resource::MemoryStreamBuffer::overflow ( int c = traits_type::eof() )

protectedvirtual

Writes a character at the current write position without advancing the write position.

Remarks: Generally this method is called when the available writing positions in the stream have been depleted and additional writing spaces can made. In our case, we can't buffer additional data so in the event the stream is expecting more, we should return the error result of EOF.

Parameters

c	The character to be written to the stream.

Returns: Returns the written character, or EOF if there was a failure.

Definition at line 229 of file memorystream.cpp.

int Mezzanine::Resource::MemoryStreamBuffer::pbackfail ( int c = traits_type::eof() )

protectedvirtual

Reverse the last character extraction operation by decrementing the read position and placing the specified character in it's place.

Parameters

c	The character to place into the stream after decrementing the read position.

Returns: Returns the current character at the read position after the operation completes, or EOF in the event of a failure.

Definition at line 206 of file memorystream.cpp.

std::streampos Mezzanine::Resource::MemoryStreamBuffer::seekoff	(	std::streamoff	off,
		std::ios_base::seekdir	way,
		std::ios_base::openmode	which = `std::ios_base::in \| std::ios_base::out`
	)

protectedvirtual

Moves the read and/or write pointers in the stream.

Remarks: Out of bounds positions will be clamped to the closest limit.

Parameters

off	The amount of advance the current position for the operation specified. Negative values will reverse the position.
way	The base point in the stream to apply the offset to.
which	Whether this should move the read pointer, write pointer, or both.

Returns: Returns the updated read or write position, based on which was provided. Returns the Read position if both were specified.

Definition at line 124 of file memorystream.cpp.

std::streampos Mezzanine::Resource::MemoryStreamBuffer::seekpos	(	std::streampos	sp,
		std::ios_base::openmode	which = `std::ios_base::in \| std::ios_base::out`
	)

protectedvirtual

Moves the read and/or write pointers to the specified position in the stream.

Remarks: Out of bounds positions will be clamped to the closest limit.

Parameters

sp	The index the current position will be moved to.
which	Whether this should move the read pointer, write pointer, or both.

Returns: Returns the updated read or write position, based on which was provided. Returns the Read position if both were specified.

Definition at line 152 of file memorystream.cpp.

std::streambuf * Mezzanine::Resource::MemoryStreamBuffer::setbuf	(	char *	s,
		std::streamsize	n
	)

protectedvirtual

Sets the buffer to be streamed from.

Parameters

s	The buffer to be wrapped.
n	The size of the buffer being wrapped.

Returns: Returns this on success, or NULL if there is a failure.

Definition at line 108 of file memorystream.cpp.

void Mezzanine::Resource::MemoryStreamBuffer::SetBuffer	(	char *	Buffer,
		const Whole	BufferSize,
		const Boole	FreeBuf
	)

Wraps an external buffer for streaming.

Parameters

Buffer	The buffer to be wrapped.
BufferSize	The size of the buffer being wrapped.
FreeBuf	Whether or not the buffer passed in should be deleted when this stream is destroyed.

Definition at line 246 of file memorystream.cpp.

void Mezzanine::Resource::MemoryStreamBuffer::SetFreeBuffer ( const Boole FreeBuf )

Sets if this should delete it's internal buffer when it is destroyed.

Parameters

FreeBuf Whether or not the buffer passed in should be deleted when this stream is destroyed.

Definition at line 305 of file memorystream.cpp.

std::streamsize Mezzanine::Resource::MemoryStreamBuffer::showmanyc ( )

protectedvirtual

Gets the number of characters remaining that can be safely extracted from this buffer.

Returns: Returns either the number of characters between the current read position and the end of the buffer, or -1 if no buffer is allocated.

Definition at line 173 of file memorystream.cpp.

int Mezzanine::Resource::MemoryStreamBuffer::sync ( )

protectedvirtual

Syncs this stream buffer with it's source.

Remarks: This buffer is the source for this type of stream, so syncing isn't required; making this an empty implementation.

Definition at line 167 of file memorystream.cpp.

int Mezzanine::Resource::MemoryStreamBuffer::uflow ( )

protectedvirtual

Gets the value at the current read position and then increments the read position.

Remarks: Under normal circumstances this method will be used along with underflow to get characters at the end of the sequence safely in the event that more data needs to be buffered. However the spec requires it to always return EOF if underflow also returns EOF. So because of how we have to implement underflow, this methods behavior is quite limited.

Returns: Returns EOF, always.

Definition at line 201 of file memorystream.cpp.

int Mezzanine::Resource::MemoryStreamBuffer::underflow ( )

protectedvirtual

Gets the value at the current read position without incrementing the read position.

Remarks: This method us used by the std::streambuf implementation for some limited amount of error checking for when the end of a stream is reached and it may be possible to access more (such as streaming a file from disk). This functionality doesn't make sense for a buffer located entirely in memory, so we must return the End-Of-File value each time we're at the end of the buffer.

Returns: Returns the current character at the read position or EOF.

Definition at line 191 of file memorystream.cpp.

std::streamsize Mezzanine::Resource::MemoryStreamBuffer::xsgetn	(	char *	s,
		std::streamsize	n
	)

protectedvirtual

Gets a number of characters starting at the read position and populates an array with them.

Parameters

s	A pointer to the array where the read characters will be placed.
n	The number of characters to read.

Returns: This returns the amount of characters retrieved

Definition at line 183 of file memorystream.cpp.

std::streamsize Mezzanine::Resource::MemoryStreamBuffer::xsputn	(	const char *	s,
		std::streamsize	n
	)

protectedvirtual

Writes a number of characters from a provided buffer to the stream.

Parameters

s	The buffer of characters that will be written to the stream.
n	The number of characters from the provided buffer that will be written to the stream.

Returns: Returns the number of characters successfully written.

Definition at line 221 of file memorystream.cpp.

Member Data Documentation

Char8* Mezzanine::Resource::MemoryStreamBuffer::BufferEnd

protected

A pointer to one passed the last element in the range of this buffer.

Definition at line 70 of file memorystream.h.

Char8* Mezzanine::Resource::MemoryStreamBuffer::BufferStart

protected

A pointer to the start of this memory buffer.

Definition at line 61 of file memorystream.h.

Boole Mezzanine::Resource::MemoryStreamBuffer::FreeBuffer

protected

Stores whether or not the memory allocated will be free'd when this buffer is deleted.

Definition at line 76 of file memorystream.h.

Whole Mezzanine::Resource::MemoryStreamBuffer::OpenMode

protected

A bitfield describing the settings this buffer was opened with.

Definition at line 73 of file memorystream.h.

The documentation for this class was generated from the following files:

/home/sqeaky/Code/MezzanineFresh/Mezzanine/src/Resource/memorystream.h
/home/sqeaky/Code/MezzanineFresh/Mezzanine/src/Resource/memorystream.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

Member Data Documentation