File object with input parameter long

[CharlesPoletowin]

The File object's readat and writeat function could not use long parameters.

The problems are as followed:

User traceback:

Exception (with type 'exceptions.OverflowError'): Python int too large to convert to C long

The test file is as followed:

if "test.txt" in listfiles():
  removefile("test.txt")
myfile=openfile("test.txt",True)  #Open a file
myfile.writeat("1234", 0)
data = myfile.readat(2**32, 0)
myfile.close()

However from the file https://github.com/SeattleTestbed/docs/blob/master/EducationalAssignments/SetMaxFileSizePartOne.md#building-the-security-layer

It seems it should allow long type in all the functions including setmaxfilesize, writeat, readat.

# The code here sets up type checking and variable hiding for you.  You should not need to change anything below here.
sec_file_def = {"obj-type":SecureFile,
                "name":"SecureFile",
                "setmaxfilesize":{"type":"func","args":(int,long, type(None)),"exceptions":Exception,"return":(type(None)),"target":SecureFile.setmaxfilesize},
                "writeat":{"type":"func","args":(str,(int,long)),"exceptions":Exception,"return":(int,type(None)),"target":SecureFile.writeat},
                "readat":{"type":"func","args":((int,long,type(None)),(int,long)),"exceptions":Exception,"return":str,"target":SecureFile.readat},
                "close":{"type":"func","args":None,"exceptions":None,"return":(bool,type(None)),"target":SecureFile.close}
           }

[ericung]

There is an issue with the following line,

data = myfile.readat(2**32, 0)

as it follows that 2^32 has a size capacity of exactly the value of 2^32 - 1. This is only knowing some fundamentals in computer science through implication of the sizelimit parameter of the readat which is implied to be an integer and an important piece of information when dealing with integer overflows.