File-IO¶

Located in file: MEL.hpp

ErrorHandler MEL::FileCreateErrorHandler(ErrorHandlerFunc func)¶

Create a file error handler.

See

MPI_File_create_errhandler

Return

Returns a handle to an error handler

Parameters

• func -

  The function to use

void MEL::FileSetErrorHandler(const File &file, const ErrorHandler &errHndl)¶

Set the error handler for a file.

See

MPI_File_set_errhandler

Parameters

• file -

  The file to attach to

• errHndl -

  The handler to use

void MEL::FileSetErrorHandler(const File &file, ErrorHandlerFunc func)¶

Set the error handler for a file.

Parameters

• file -

  The file to attach to

• func -

  The function to use

ErrorHandler MEL::FileGetErrorHandler(const File &file)¶

Get the error handler for a file.

See

MPI_File_get_errhandler

Return

Returns a handle to the error handler

Parameters

• file -

  The file to attach to

FileMode MEL::FileGetMode(const File &file)¶

Get the mode a file was opened with.

See

MPI_File_get_amode

Return

Returns the file mode

Parameters

• file -

  The file to attach to

bool MEL::FileIsAtomic(const File &file)¶

Is the file opened in an atomic mode?

See

MPI_File_get_atomicity

Return

Returns true is the file is opened atomically

Parameters

• file -

  The file to attach to

void MEL::FileSetAtomicity(const File &file, const bool atom)¶

Set the atomicity of the file handle.

See

MPI_File_set_atomicity

Parameters

• file -

  The file to attach to

• atom -

  Boolean value representing atomicity

Offset MEL::FileGetByteOffset(const File &file, const Offset offset)¶

Get the byte position of the file cursor relative to a given location.

See

MPI_File_get_byte_offset

Return

Returns the number of bytes from the given offset

Parameters

• file -

  The file to attach to

• offset -

  The relative offset to measure byte distance against

Group MEL::FileGetGroup(const File &file)¶

Get the comm group a file was opened as a part of.

See

MPI_File_get_group

Return

Returns comm group the file handle belongs to

Parameters

• file -

  The file to attach to

Info MEL::FileGetInfo(const File &file)¶

Get the MPI_Info object attached to a file handle.

See

MPI_File_get_info

Return

Returns the info object

Parameters

• file -

  The file to attach to

void MEL::FileSetInfo(const File &file, const Info &info)¶

Set the MPI_Info object attached to a file handle.

See

MPI_File_set_info

Parameters

• file -

  The file to attach to

• info -

  The info object to attach

Offset MEL::FileGetPosition(const File &file)¶

Get the position of the file cursor.

See

MPI_File_get_position

Return

Returns the location of the file cursor in bytes

Parameters

• file -

  The file to attach to

Offset MEL::FileGetPositionShared(const File &file)¶

Get the position of the shared file cursor.

See

MPI_File_get_position_shared

Return

Returns the location of the shared file cursor in bytes

Parameters

• file -

  The file to attach to

Offset MEL::FileGetSize(const File &file)¶

Get the size of the file in bytes.

See

MPI_File_get_size

Return

Returns the size of the file in bytes

Parameters

• file -

  The file to attach to

void MEL::FileSetSize(const File &file, const Offset size)¶

Set the size of the file in bytes.

See

MPI_File_set_size

Parameters

• file -

  The file to attach to

• size -

  The size in bytes to set the file size to

Aint MEL::FileGetTypeExtent(const File &file, const Datatype &datatype)¶

Get the extent of the derived type set to the file handle.

See

MPI_File_get_type_extent

Return

Returns the extent of the type

Parameters

• file -

  The file to attach to

• datatype -

  The derived datatype to measure the extent of

File MEL::FileOpen(const Comm &comm, const std::string &path, const FileMode amode)¶

Open a file and return a handle to it.

See

MPI_File_open, MPI_File_set_errhandler

Return

Returns a handle to the file pointer

Parameters

• comm -

  The comm world to open the file with

• path -

  The path to the desired file

• amode -

  The file mode to open the file with

File MEL::FileOpenIndividual(const std::string &path, const FileMode amode)¶

Open a file on an individual process and return a handle to it.

Return

Returns a handle to the file pointer

Parameters

• path -

  The path to the desired file

• amode -

  The file mode to open the file with

void MEL::FileDelete(const std::string &path)¶

Delete a file by its path.

See

MPI_File_delete

Parameters

• path -

  The path to the file to be deleted

void MEL::FileClose(File &file)¶

Close the file attached to the given file handle.

See

MPI_File_close

Parameters

• file -

  The file handle to be closed

void MEL::FilePreallocate(const File &file, const Offset fileSize)¶

Preallocate the opened file to the given size on the file system.

See

MPI_File_preallocate

Parameters

• file -

  The file to be preallocated

• fileSize -

  The size of the file in bytes

void MEL::FileSeek(const File &file, const Offset offset, const SeekMode seekMode = MEL::SeekMode::SET)¶

Move the file cursor to a specific position.

See

MPI_File_seek

Parameters

• file -

  The file

• offset -

  The position to move the file cursor to

• seekMode -

  The mode to move the cursor by

void MEL::FileSeekShared(const File &file, const Offset offset, const SeekMode seekMode = MEL::SeekMode::SET)¶

Move the shared file cursor to a specific position.

The same values must be provided by all processes

See

MPI_File_seek_shared

Parameters

• file -

  The shared file

• offset -

  The position to move the file cursor to

• seekMode -

  The mode to move the cursor by

void MEL::FileSync(const File &file)¶

Force all queued and pending disk operations on a file to be completed.

See

MPI_File_sync

Parameters

• file -

  The file to be synchronized

void MEL::FileSetView(const File &file, const Offset offset, const Datatype elementaryType, const Datatype fileType, const std::string &datarep = "native")¶

Set the view of a file handle for subsequent read/writes.

See

MPI_File_set_view

Parameters

• file -

  The file handle

• offset -

  Byte offset from start of the file

• elementaryType -

  The derived type representing the type of each element to be written

• fileType -

  The derived type representing the structure of data to be written

• datarep -

  String argument telling the MPI implementation how data is represented. Default is “native”

void MEL::FileSetView(const File &file, const FileView &view)¶

Set the view of a file handle for subsequent read/writes.

Parameters

• file -

  The file handle

• view -

  A utility structure that stores the values of a file view

void MEL::FileGetView(const File &file, Offset &offset, Datatype &elementaryType, Datatype &fileType, std::string &datarep)¶

Get the view attached to a file handle.

See

MPI_File_get_view

Parameters

• file -

  The file handle

• offset -

  Byte offset from start of the file

• elementaryType -

  The derived type representing the type of each element to be written

• fileType -

  The derived type representing the structure of data to be written

• datarep -

  String argument telling the MPI implementation how data is represented. Default is “native”

FileView MEL::FileGetView(const File &file)¶

Get the view attached to a file handle.

Return

Returns a utility structure that stores the values of a file view

Parameters

• file -

  The file handle

Status MEL::FileWrite(const File &file, const void *sptr, const int snum, const Datatype &datatype)¶

Write to file from a single process.

See

MPI_File_write

Return

A status object

Parameters

• file -

  The file handle

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

• datatype -

  The derived type representing the elements to be written

Status MEL::FileWriteAll(const File &file, const void *sptr, const int snum, const Datatype &datatype)¶

Write to file from all processes that opened the file.

See

MPI_File_write_all

Return

A status object

Parameters

• file -

  The file handle

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

• datatype -

  The derived type representing the elements to be written

Status MEL::FileWriteAt(const File &file, const Offset offset, const void *sptr, const int snum, const Datatype &datatype)¶

Write to file from a single process at the desired offset.

See

MPI_File_write_at

Return

A status object

Parameters

• file -

  The file handle

• offset -

  Byte offset into the file to write at

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

• datatype -

  The derived type representing the elements to be written

Status MEL::FileWriteAtAll(const File &file, const Offset offset, const void *sptr, const int snum, const Datatype &datatype)¶

Write to file from all processes that opened the file at the desired offset.

See

MPI_File_write_at_all

Return

A status object

Parameters

• file -

  The file handle

• offset -

  Byte offset into the file to write at

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

• datatype -

  The derived type representing the elements to be written

Status MEL::FileWriteOrdered(const File &file, const void *sptr, const int snum, const Datatype &datatype)¶

Write to file from all processes that opened the file in sequence.

See

MPI_File_write_ordered

Return

A status object

Parameters

• file -

  The file handle

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

• datatype -

  The derived type representing the elements to be written

Status MEL::FileWriteShared(const File &file, const void *sptr, const int snum, const Datatype &datatype)¶

Write to file from any processes that opened the file in parallel.

See

MPI_File_write_shared

Return

A status object

Parameters

• file -

  The file handle

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

• datatype -

  The derived type representing the elements to be written

Request MEL::FileIwrite(const File &file, const void *sptr, const int snum, const Datatype &datatype)¶

Non-Blocking.

Write to file from a single processes

See

MPI_File_iwrite

Return

A request object

Parameters

• file -

  The file handle

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

• datatype -

  The derived type representing the elements to be written

Request MEL::FileIwriteAt(const File &file, const Offset offset, const void *sptr, const int snum, const Datatype &datatype)¶

Non-Blocking.

Write to file from a single process at the desired offset

See

MPI_File_iwrite_at

Return

A request object

Parameters

• file -

  The file handle

• offset -

  Byte offset into the file to write to

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

• datatype -

  The derived type representing the elements to be written

Request MEL::FileIwriteShared(const File &file, const void *sptr, const int snum, const Datatype &datatype)¶

Non-Blocking.

Write to file from any processes that opened the file in parallel

See

MPI_File_iwrite_shared

Return

A request object

Parameters

• file -

  The file handle

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

• datatype -

  The derived type representing the elements to be written

Status MEL::FileRead(const File &file, void *rptr, const int rnum, const Datatype &datatype)¶

Read from file from a single process.

See

MPI_File_read

Return

A status object

Parameters

• file -

  The file handle

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

• datatype -

  The derived type representing the elements to be read

Status MEL::FileReadAll(const File &file, void *rptr, const int rnum, const Datatype &datatype)¶

Read from file from all processes that opened the file.

See

MPI_File_read_all

Return

A status object

Parameters

• file -

  The file handle

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

• datatype -

  The derived type representing the elements to be read

Status MEL::FileReadAt(const File &file, const Offset offset, void *rptr, const int rnum, const Datatype &datatype)¶

Read from file from a single process at the desired offset.

See

MPI_File_read_at

Return

A status object

Parameters

• file -

  The file handle

• offset -

  Byte offset into the file to read from

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

• datatype -

  The derived type representing the elements to be read

Status MEL::FileReadAtAll(const File &file, const Offset offset, void *rptr, const int rnum, const Datatype &datatype)¶

Read from file from all processes that opened the file at the desired offset.

See

MPI_File_read_at_all

Return

A status object

Parameters

• file -

  The file handle

• offset -

  Byte offset into the file to read from

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

• datatype -

  The derived type representing the elements to be read

Status MEL::FileReadOrdered(const File &file, void *rptr, const int rnum, const Datatype &datatype)¶

Read from file from all processes that opened the file in sequence.

See

MPI_File_read_ordered

Return

A status object

Parameters

• file -

  The file handle

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

• datatype -

  The derived type representing the elements to be read

Status MEL::FileReadShared(const File &file, void *rptr, const int rnum, const Datatype &datatype)¶

Read from file from any processes that opened the file in parallel.

See

MPI_File_read_shared

Return

A status object

Parameters

• file -

  The file handle

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

• datatype -

  The derived type representing the elements to be read

Request MEL::FileIread(const File &file, void *rptr, const int rnum, const Datatype &datatype)¶

Non-Blocking.

Read from file from a single process

See

MPI_File_iread

Return

A request object

Parameters

• file -

  The file handle

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

• datatype -

  The derived type representing the elements to be read

Request MEL::FileIreadAt(const File &file, const Offset offset, void *rptr, const int rnum, const Datatype &datatype)¶

Non-Blocking.

Read from file from a single process at the desired offset

See

MPI_File_iread_at

Return

A request object

Parameters

• file -

  The file handle

• offset -

  Byte offset into the file to read from

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

• datatype -

  The derived type representing the elements to be read

Request MEL::FileIreadShared(const File &file, void *rptr, const int rnum, const Datatype &datatype)¶

Non-Blocking.

Read from file from any process that opened the file in parallel

See

MPI_File_iread_shared

Return

A request object

Parameters

• file -

  The file handle

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

• datatype -

  The derived type representing the elements to be read

template <typename T>

Status MEL::FileWrite(const File &file, const T *sptr, const int snum)¶

Write to file from a single process.

Element size determined by template type

Return

A status object

Parameters

• file -

  The file handle

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

template <typename T>

Status MEL::FileWriteAt(const File &file, const Offset offset, const T *sptr, const int snum)¶

Write to file from a single process at the desired offset.

Element size determined by template type

Return

A status object

Parameters

• file -

  The file handle

• offset -

  Byte offset into the file to write to

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

template <typename T>

Status MEL::FileWriteAll(const File &file, const T *sptr, const int snum)¶

Write to file from all processes that opened the file.

Element size determined by template type

Return

A status object

Parameters

• file -

  The file handle

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

template <typename T>

Status MEL::FileWriteAtAll(const File &file, const Offset offset, const T *sptr, const int snum)¶

Write to file from all processes that opened the file at the desired offset.

Element size determined by template type

Return

A status object

Parameters

• file -

  The file handle

• offset -

  Byte offset into the file to write to

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

template <typename T>

Status MEL::FileWriteOrdered(const File &file, const T *sptr, const int snum)¶

Write to file from all processes that opened the file in sequence.

Element size determined by template type

Return

A status object

Parameters

• file -

  The file handle

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

template <typename T>

Status MEL::FileWriteShared(const File &file, const T *sptr, const int snum)¶

Write to file from any processes that opened the file in parallel.

Element size determined by template type

Return

A status object

Parameters

• file -

  The file handle

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

template <typename T>

Status MEL::FileRead(const File &file, T *rptr, const int rnum)¶

Read from file from a single process.

Element size determined by template type

Return

A status object

Parameters

• file -

  The file handle

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

template <typename T>

Status MEL::FileReadAt(const File &file, const Offset offset, T *rptr, const int rnum)¶

Read from file from a single process at the desired offset.

Element size determined by template type

Return

A status object

Parameters

• file -

  The file handle

• offset -

  Byte offset into the file to read from

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

template <typename T>

Status MEL::FileReadAll(const File &file, T *rptr, const int rnum)¶

Read from file from all processes that opened the file.

Element size determined by template type

Return

A status object

Parameters

• file -

  The file handle

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

template <typename T>

Status MEL::FileReadAtAll(const File &file, const Offset offset, T *rptr, const int rnum)¶

Read from file from all processes that opened the file at the desired offset.

Element size determined by template type

Return

A status object

Parameters

• file -

  The file handle

• offset -

  Byte offset into the file to read from

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

template <typename T>

Status MEL::FileReadOrdered(const File &file, T *rptr, const int rnum)¶

Read from file from all processes that opened the file in sequence.

Element size determined by template type

Return

A status object

Parameters

• file -

  The file handle

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

template <typename T>

Status MEL::FileReadShared(const File &file, T *rptr, const int rnum)¶

Read from file from any processes that opened the file in parallel.

Element size determined by template type

Return

A status object

Parameters

• file -

  The file handle

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

template <typename T>

Request MEL::FileIwrite(const File &file, const T *sptr, const int snum)¶

Non-Blocking.

Write to file from a single process. Element size determined by template type

Return

A request object

Parameters

• file -

  The file handle

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

template <typename T>

Request MEL::FileIwriteAt(const File &file, const Offset offset, const T *sptr, const int snum)¶

Non-Blocking.

Write to file from all processes that opened the file at the desired offset. Element size determined by template type

Return

A request object

Parameters

• file -

  The file handle

• offset -

  Byte offset into the file to write to

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

template <typename T>

Request MEL::FileIwriteShared(const File &file, const T *sptr, const int snum)¶

Non-Blocking.

Write to file from any processes that opened the file in parallel. Element size determined by template type

Return

A request object

Parameters

• file -

  The file handle

• sptr -

  Pointer to the memory to be written

• snum -

  The number of elements to write

template <typename T>

Request MEL::FileIread(const File &file, T *rptr, const int rnum)¶

Non-Blocking.

Read from file from a single process. Element size determined by template type

Return

A request object

Parameters

• file -

  The file handle

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

template <typename T>

Request MEL::FileIreadAt(const File &file, const Offset offset, T *rptr, const int rnum)¶

Non-Blocking.

Read from file from a single process at the desired offset. Element size determined by template type

Return

A request object

Parameters

• file -

  The file handle

• offset -

  Byte offset into the file to read from

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read

template <typename T>

Request MEL::FileIreadShared(const File &file, T *rptr, const int rnum)¶

Non-Blocking.

Read from file from any processes that opened the file in parallel. Element size determined by template type

Return

A request object

Parameters

• file -

  The file handle

• rptr -

  Pointer to the memory to be read into

• rnum -

  The number of elements to read