Constructs the object with a default intermediate buffer size.

The size of the intermediate buffer is the value of the constant KDefaultFileBufSize.

Writes any outstanding data from the intermediate buffer before freeing the intermediate buffer and closing the attached file.

Detaches the file from this stream buffer.

The intermediate buffer's read and write marks are not changed, and the stream positions are not changed. This means that the contents of the file should not change while it is detached.

Attach() Reattach()

Reads data from the intermediate buffer into the specified memory location.

The function calls the virtual function UnderfLowL() to give concrete implementations the chance to refill the intermediate buffer, and satisfy the caller's requirements.

This implementation overrides the one supplied by the base class MStreamBuf, and is called by, MStreamBuf::ReadL(TAny*,TInt).

MStreamBuf::ReadL() MStreamBuf::DoReadL()

Synchronises the stream buffer with the stream, leaving if any error occurs.

In effect, this ensures that buffered data is delivered to the stream.

It is called by SynchL().

This implementation is empty, but classes derived from MStreamBuf can provide their own implementation, if necessary.

MStreamBuf::SynchL()

Writes data from the specified memory location into the intermediate buffer.

The function calls the virtual function OverfLowL() to give concrete implementations the chance to forward the intermediate buffer content to its destination.

This implementation overrides the one supplied by the base class MStreamBuf, and is called by MStreamBuf::WriteL(const TAny*,TInt).

MStreamBuf::WriteL() MStreamBuf::DoWriteL()

Writes data from the specified descriptor into this stream buffer.

This function is called by WriteL(const TDesC8&,TInt,TRequestStatus&).

This implementation deals with the request synchronously, and completes the request with KErrNone. Other implementations may choose to deal with this in a true asynchronous manner.

In addition, the write operation itself uses the DoWriteL(TAny*,TInt) variant.

MStreamBuf::WriteL()

Returns the number of bytes that are/were in the read area of the intermediate buffer yet to be passed to the user.

MStreamBuf::TRead

Opens the specified file and attaches it to this stream buffer.

If the file cannot be opened, then it is not attached to this stream buffer.

Attach() TFileMode RFile

Empties the intermediate buffer and resets the start and end points of the write area.

The implementation of this function depends on the way the stream itself is implemented. For example, the in-memory streams have simple implementations.

Re-attaches the specified file to this stream buffer.

The intermediate buffer's read and write marks are not changed, and the stream positions are not changed.

The file should be the one that was detached using the Detach() function.

Attach() Detach()

Replaces the file with the specified name and attaches it to this stream buffer.

If there is an existing file with the same name, then this function overwrites it. If the file does not already exist, it is created.

If the file cannot be replaced, then it is not attached to this stream buffer.

Attach() TFileMode RFile

Frees the intermediate buffer.

If there is any read data in the intermediate buffer, then the function reverts the read position within the stream.

The intermediate buffer must not contain any outstanding write data, otherwise the function raises a STORE-File 6 panic.

Sets the start and end points of the read area within the intermediate buffer.

MStreamBuf::TRead TStreamBuf::SetBuf

Sets the start and end points of the write area within the intermediate buffer.

A start point is always within an area; an end point is always the first byte beyond the end of an area.

MStreamBuf::TWrite

Sets the start and end points of the read and/or the write area within the intermediate buffer.

A start point is always within an area; an end point is always the first byte beyond the end of an area.

MStreamBuf::TRead MStreamBuf::TWrite

Sets the start position of the write area within the intermediate buffer taking into account seeks.

Changes the size of the file attached to this buffer to the specified value.

Writes any outstanding data from the intermediate buffer to the stream hosted by the file. Any data in the intermediate buffer that would lie beyond the end of the truncated file, is not written.

Returns the number of bytes of outstanding data in the intermediate buffer that is yet to be written, taking into account any changes brought about by seeks.

MStreamBuf::TWrite

Creates and opens a temporary file with a unique name and attaches it to this stream buffer.

Attach() TFileMode RFile

Re-fills the intermediate buffer and resets the start and end points of the read area.

The implementation of this function depends on the way the stream itself is implemented. For example, the in-memory streams have simple implementations.