Popular recipes tagged "meta:requires=math" and "files" but not "pasw"http://code.activestate.com/recipes/tags/meta:requires=math+files-pasw/2006-04-26T10:11:38-07:00ActiveState Code Recipesdal_2.py (Python)
2006-04-26T09:53:56-07:00Stephen Chappellhttp://code.activestate.com/recipes/users/2608421/http://code.activestate.com/recipes/492210-dal_2py/
<p style="color: grey">
Python
recipe 492210
by <a href="/recipes/users/2608421/">Stephen Chappell</a>
(<a href="/recipes/tags/files/">files</a>).
</p>
<p>The class DAL2 provides a way to label
blocks on a hard drive while storing
such information on the hard drive
itself. The information is kept in the
BIT (Block Information Table) and is
written out to disk when appropriate.
Otherwise, the BIT is kept in memory
for efficiency. The hard disk is again
presented as a collection of blocks but
completely hides disk IO as a result of
Disk Abstraction Layer 1.</p>
dal_4.py (Python)
2006-04-26T10:11:38-07:00Stephen Chappellhttp://code.activestate.com/recipes/users/2608421/http://code.activestate.com/recipes/492212-dal_4py/
<p style="color: grey">
Python
recipe 492212
by <a href="/recipes/users/2608421/">Stephen Chappell</a>
(<a href="/recipes/tags/files/">files</a>).
</p>
<p>While DAL3 created and enforced a distinction
among directory blocks, file blocks, and
data blocks (along with providing an easy
interface to directory blocks and files blocks),
DAL4 introduces the concept of linking all of
these blocks together and giving names to
directories and files. While still primitive,
the file system is now unified and allows more
advanced abstractions to be built on top of it.</p>
dal_3.py (Python)
2006-04-26T10:01:43-07:00Stephen Chappellhttp://code.activestate.com/recipes/users/2608421/http://code.activestate.com/recipes/492211-dal_3py/
<p style="color: grey">
Python
recipe 492211
by <a href="/recipes/users/2608421/">Stephen Chappell</a>
(<a href="/recipes/tags/files/">files</a>).
</p>
<p>Disk Abstraction Layer 3 provides a more
useful framework for secondary memory and
provides an abstract interface for
implementing a generic file system. It
renumbers the blocks on the hard drive to
start at block 1 so that block 0 can be
considered a NULL reference. At a lower
level, block 0 would be seen to be where
the OS can keep a seed for its random
number generator (interface provided).</p>