IoMemoryInterface Class Reference

#include <iomemory.h>

Detailed Description

Helper class for Url of type maxon::URLSCHEME_MEMORY. It turns memory blocks into InputStreams or OutputStreams. This way a memory block can be handled like a real file. The following example shows how to write into a memory file.

IoMemoryRef mfh = IoMemoryRef::Create() iferr_return;
Url writemem = mfh.GetUrl() iferr_return;
OutputStreamRef outmem = writemem.OpenOutputStream() iferr_return;
outmem.Write("ABCDE", 5);
outmem.Write("FGHIJ", 5);
outmem.Close();
 
for (Int i = 0; i < mfh.GetSize(); i++)
{
  OutputWithFlags(OUTPUT::DIAGNOSTIC | OUTPUT::NOLINEBREAK, "@{c}", mfh[i]);
}

IoMemoryRef mem = IoMemoryRef::Create() iferr_return;
Char* buffer = NewMem(Char, size) iferr_return;
mem.PrepareReadBuffer(ToBlock(buffer, size),
  [](const Char*& buffer)
  {
    DeleteMem(buffer);
  }) iferr_return;

Public Types
using	FreeBufferCallback = Delegate< void(const Char *&buffer)>

Public Member Functions
MAXON_METHOD Result< void >	PrepareReadBuffer (const Block< const Char > &buffer, const FreeBufferCallback &freeBufferCallback)
MAXON_METHOD Result< void >	Reset (Int size)
MAXON_METHOD const Char &	operator[] (Int idx)
MAXON_METHOD Int	GetSize () const
MAXON_METHOD Bool	IsWritable () const
MAXON_METHOD Result< Url >	GetUrl () const
MAXON_METHOD Result< void >	ReadBytes (Int position, const Block< Byte > &data) const
MAXON_METHOD Result< Int >	ReadBytesEOS (Int position, const Block< Byte > &data) const
MAXON_METHOD Result< void >	WriteBytes (Int position, const Block< const Byte > &data)
MAXON_METHOD Result< InputStreamRef >	OpenInputStream (OPENSTREAMFLAGS flags) const
MAXON_METHOD Result< OutputStreamRef >	OpenOutputStream (OPENSTREAMFLAGS flags)
MAXON_METHOD Result< InOutputStreamRef >	OpenInOutputStream (OPENSTREAMFLAGS flags)

Static Public Member Functions
static MAXON_METHOD IoMemoryInterface *	Alloc (MAXON_SOURCE_LOCATION_DECLARATION)
static MAXON_METHOD IoMemoryInterface *	Alloc (MAXON_SOURCE_LOCATION_DECLARATION, const IoMemoryInterface &src)

Private Member Functions
	MAXON_INTERFACE_NONVIRTUAL (IoMemoryInterface, MAXON_REFERENCE_NORMAL, "net.maxon.interface.iomemory")

Member Typedef Documentation

FreeBufferCallback

using FreeBufferCallback = Delegate<void(const Char*& buffer)>

Argument type of PrepareReadBuffer().

Member Function Documentation

MAXON_INTERFACE_NONVIRTUAL()

MAXON_INTERFACE_NONVIRTUAL ( IoMemoryInterface  , MAXON_REFERENCE_NORMAL  , "net.maxon.interface.iomemory"    )

private

Alloc() [1/2]

static MAXON_METHOD IoMemoryInterface* Alloc ( MAXON_SOURCE_LOCATION_DECLARATION  )

static

Allocators for common use.

Parameters

[in]

allocLocation

Source location.

Alloc() [2/2]

static MAXON_METHOD IoMemoryInterface* Alloc ( MAXON_SOURCE_LOCATION_DECLARATION  , const IoMemoryInterface &  src  )

static

PrepareReadBuffer()

MAXON_METHOD Result<void> PrepareReadBuffer	(	const Block< const Char > &	buffer,
		const FreeBufferCallback &	freeBufferCallback
	)

Prepares a given memory block for reading. The ownership of the memory can be transfered to the object. The memory will be freed by calling DeleteMem().

Parameters

[in]	buffer	Block with the available data to read from.
[in]	freeBufferCallback	If a callback/lambda is given the memory should be owned by the object and will be freed by calling the callback. Within the callback the memory should be freed and the pointer must be set to nullptr! If "nullptr" the memory needs to be freed by yourself and needs to be kept until this class is not used anymore.

Returns

OK on success.

Reset()

MAXON_METHOD Result<void> Reset

(

Int

size

)

Resets the class and preallocate a given size of bytes. In read mode the memory can e.g. be filled with WriteBytes. Write mode only needs size 0 as the data grows dynamically.

Parameters

[in]

size

Requested size of bytes in the buffer. This memory can be accessed via operator[] or ReadBytes/WriteBytes.

Returns

OK on success.

operator[]()

MAXON_METHOD const Char& operator[]

(

Int

idx

)

Accesses operator to the buffer.

Parameters

[in]

idx

Index of the data to read.

Returns

Value of the position in the buffer.

GetSize()

MAXON_METHOD Int GetSize

(

)

const

Gets the current buffer size.

Returns

Size of the internal buffer.

IsWritable()

MAXON_METHOD Bool IsWritable

(

)

const

Returns whether the object is writable (true) or not (false)

Returns

The current mode.

GetUrl()

MAXON_METHOD Result<Url> GetUrl

(

)

const

Creates an Url for this IoMemoryRef class. This name can be used to call InputStreamRef and OutputStreamRef functions with memory files. The Url can be passed to any function that accepts Urls for reading/writing files. E.g. reading/writing images from a memory block etc. InOutputStreamRef is not supported.

Returns

Url for further operations.

ReadBytes()

MAXON_METHOD Result<void> ReadBytes	(	Int	position,
		const Block< Byte > &	data
	)		const

Copies the classes buffer from position to destData with the given length.

Parameters

[in]	position	Start copying memory from this offset. The position is the offset in the classes buffer, not the destination buffer.
[in]	data	Destination buffer.

Returns

OK on success.

ReadBytesEOS()

MAXON_METHOD Result<Int> ReadBytesEOS	(	Int	position,
		const Block< Byte > &	data
	)		const

Copies the classes buffer from position to destData with the given length.

Parameters

[in]	position	Start copying memory from this offset. The position is the offset in the classes buffer, not the destination buffer.
[in]	data	Destination buffer.

Returns

Number of bytes copied.

WriteBytes()

MAXON_METHOD Result<void> WriteBytes	(	Int	position,
		const Block< const Byte > &	data
	)

Writes the given sourceData at position in the classes buffer with the given length.

Parameters

[in]	position	Start copying memory to this offset. The position is the offset in the classes buffer, not the source data buffer.
[in]	data	Source data buffer.

Returns

OK on success.

OpenInputStream()

MAXON_METHOD Result<InputStreamRef> OpenInputStream

(

OPENSTREAMFLAGS

flags

)

const

OpenOutputStream()

MAXON_METHOD Result<OutputStreamRef> OpenOutputStream

(

OPENSTREAMFLAGS

flags

)

OpenInOutputStream()

MAXON_METHOD Result<InOutputStreamRef> OpenInOutputStream

(

OPENSTREAMFLAGS

flags

)