wiki:WikiStart

Version 7 (modified by zooko, 13 years ago) (diff)

http://allmydata => https://tahoe-lafs

zfec

This package implements an "erasure code", or "forward error correction code".

You may use this package under the GNU General Public License, version 2 or, at your option, any later version. You may use this package under the Transitive Grace Period Public Licence, version 1.0. (You may choose to use this package under the terms of either licence, at your option.) See the file COPYING.GPL for the terms of the GNU General Public License, version 2. See the file COPYING.TGPPL.html for the terms of the Transitive Grace Period Public Licence, version 1.0.

The most widely known example of an erasure code is the RAID-5 algorithm which makes it so that in the event of the loss of any one hard drive, the stored data can be completely recovered. The algorithm in the zfec package has a similar effect, but instead of recovering from the loss of only a single element, it can be parameterized to choose in advance the number of elements whose loss it can tolerate.

This package is largely based on the old "fec" library by Luigi Rizzo et al., which is a mature and optimized implementation of erasure coding. The zfec package makes several changes from the original "fec" package, including addition of the Python API, refactoring of the C API to support zero-copy operation, a few clean-ups and optimizations of the core code itself, and the addition of a command-line tool named "zfec".

how to use it

See the README.rst file for complete instructions.

source code

darcs get --partial https://tahoe-lafs.org/source/zfec/trunk

or visit

http://pypi.python.org/pypi/zfec

mailing list

Currently it is used only for announcements of new releases of zfec, but there are plenty of subscribers who are interested in zfec and would probably be happy to answer your questions or respond to your ideas about how to improve zfec:

zfec-dev

how to use this web site (trac)

For a complete list of local wiki pages, see TitleIndex.