EAF_OpenPersist

Description:

Open a persistent file

Prototype:

integer EAF_OpenPersist(fname, type)

character *(*) fname

integer type

Parameters:

fname

Character string of a globally unique filename (path may be fully qualified)

type

Read write permissions. Legal values are CHEMIO_W, CHEMIO_R, and CHEMIO_RW

Returns:

File handle, or CHEMIO_FAIL upon error

EAF_OpenScratch

Description:

Open a scratch file which is automatically deleted upon close

Prototype:

integer EAF_OpenScratch(fname, type)

character *(*) fname

integer type

Parameters:

fname

Character string of a globally unique filename (path may be fully qualified)

type

Read write permissions. Legal values are CHEMIO_W, CHEMIO_R, and CHEMIO_RW

Returns:

File handle, or CHEMIO_FAIL upon error

EAF_Write

Description:

Synchronously write to the file specified by the file handle

Prototype:

integer EAF_Write(fh, offset, buf, bytes)

integer fh

integer offset

_______ buf

integer bytes

Parameters:

fh

File Handle offset Absolute offset, in bytes, to start writing at

buf

Scalar or array of data

bytes

Size of buffer in bytes

Returns:

Number of bytes written, or CHEMIO_FAIL if an error occured

EAF_AWrite

Description:

Asynchronously write to the file specified by the file handle, and return a handle to the asynchronous operation.

If there are more than MAX_AIO_REQ asynchronous requests (reading and/or writing) pending, the operation is handled in a synchronous fashion and returns a CHEMIO_DONE handle.

On architectures where asynchronous I/O operations are not supported, all requests are handled synchronously, returning a CHEMIO_DONE handle.

Prototype:

integer EAF_AWrite(fh, offset, buf, bytes, req_id)

integer fh

integer offset

_______ buf

integer bytes

integer req_id

Parameters:

fh

File Handle

offset

Absolute offset, in bytes, to start writing at

buf

Scalar or array of data

bytes

Size of buffer, in bytes

req_id

Handle of asynchronous operation

Returns:

CHEMIO_OK if succeeded, or CHEMIO_FAIL if an error occured

EAF_Read

Description:

Synchronously read from the file specified by the file handle

Prototype:

integer EAF_Read(fh, offset, buf, bytes)

integer fh

integer offset

_______ buf

integer bytes

integer req_id

Parameters:

fh

File Handle

offset

Absolute offset, in bytes, to start writing at

buf

Scalar or array of data

bytes

Size of buffer, in bytes

Returns:

Number of bytes read, or CHEMIO_FAIL if an error occured

EAF_ARead

Description:

Asynchronously read from the file specified by the file handle, and return a handle to the asynchronous operation.

If there are more than MAX_AIO_REQ asynchronous requests (reading and/or writing) pending, the operation is handled in a synchronous fashion and returns a CHEMIO_DONE handle.

On architectures where asynchronous I/O operations are not supported, all requests are handled synchronously, returning a CHEMIO_DONE handle.

Prototype:

integer EAF_ARead(fh, offset, buf,bytes, req_id)

integer fh

integer offset

_______ buf

integer bytes

integer req_id

Parameters:

fh

File Handle

offset

Absolute offset, in bytes, to start reading from

buf

Scalar or array of data

bytes

Size of buffer, in bytes

req_id

Handle of asynchronous operation

Returns:

CHEMIO_OK if succeeded, or CHEMIO_FAIL if an error occured

EAF_Probe

Description:

Determine if an asynchronous request has completed or is pending.

Prototype:

integer EAF_Probe(id, status)

integer id 

integer status

Parameters:

id

Handle of asynchronous request

status Pending or completed status argument

Returns:

CHEMIO_OK if probe succeeded, else returns CHEMIO_FAIL.

status returns CHEMIO_PENDING if the asyncronous operation is not complete, or CHEMIO_DONE if finished.

If the asynchronous request is complete, id is invalidated with CHEMIO_DONE.

EAF_Wait

Description:

Wait for the completion of the asynchronous request, id

Prototype:

integer EAF_Wait(id)

integer id 

Parameters:

id

Handle of asynchronous request

Returns:

CHEMIO_OK if EAF is able to wait for completion, else returns CHEMIO_FAIL.

id is invalidated with CHEMIO_DONE.

EAF_Close

Description:

Close a file

Prototype:

integer EAF_Close(fh)

integer fh 

Parameters:

fh

File Handle

Returns:

CHEMIO_OK if the file was closed, else returns CHEMIO_FAIL.