Gurmeet Singh added the comment: Please consider following before making a decision:
>> io.FileIO does not implements single OS system call on read() - instead >> reads a file until EOF i.e. ignores the arguments supplied to read() >Your experiments show otherwise, the argument supplied to read() is >observed: >if you call read(1024), at most 1024 bytes are returned, etc. >It's only if you call read() without an argument that the file is being >read >until EOF. I said this because I saw the following in the docs: >class io.RawIOBase >read(n=-1) >Read up to n bytes from the object and return them. As a convenience, >if n is >unspecified or -1, readall() is called. Otherwise, only one >system call is >ever made. Fewer than n bytes may be returned if the >operating system call >returns fewer than n bytes. If only one system call is being made, then I think that fl.read(256) and fl.read(70934549) should take same amount of time to complete - assuming disk I/O is the time consuming factor in this operation (as compared to memory processing). I am only saying that instead of one system call being made - the whole size specified by read is being read (by multiple system calls - as it appears to me). Please tell me if I am wrong here. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue17440> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
