maxIOSize

Type: Integer

The maxIOSize property of the File class contains the maximum size in bytes of an I/O operation. A read or write operation that is larger than the value of maxIOSize property is performed in a number of I/O operations, which do not exceed the value of maxIOSize property.

The default value of zero (0) units performs the read or write as a single I/O operation.

The code fragment in the following example shows the use of the maxIOSize property.

    create file transient;
    file.mode := File.Mode_Output;
    file.kind := File.Kind_Binary;
    file.fileName := "\\host\share\filename.dat";
    file.maxIOSize := 16*1024;  //16KB I/O's
    file.open;
    buffer[80*1024*1024] := 'x'.Binary;  // Create an 80MB buffer
    file.writeBinary(buffer);

This causes 5120 write I/O operations each 16K bytes in size to the destination file, rather than a single 80M byte write that would fail under current Windows operating systems raising an exception (5040 - Insufficient System Resources).