Why
we need to “Align File to Piece Boundary”?
A torrent is
a file that contains the basic information about a file or set of
files. BitTorrent Clients exchange these files according to this
information. The clients do not transfer files by files but by
pieces which have the same size. All the files in this torrent are
splitted into pieces, the size of which has been appointed by the
torrent file. If there is more than one file to transfer, there
might be some pieces contain head of file A and meantime tail of
file B. As a result, although all the content in file A downloaded,
the status of the file might keep permanent “99.9% finished”
because some content from file B in this piece has not been
downloaded. To resolve this problem, we have to make every piece
only contain content from the same file. In BitComet, we implement
this function by “Align File to Piece
Boundary”
How
to Align File to Piece Boundary?
If the last
piece of a file is too small to be a full piece, than we add a
padding file into the torrent just behind this file. In this last
piece, there are only contents from this file and the padding file,
so every file is separately. Also, the “99.9% finished” problem has
been solved. When communicating with each others, BitComet clients
(version 0.86 or above) skip these padding files.
How to
enable
“Align
File to Piece
Boundary”?
This function is
enabled as default when you make a torrent with bitcomet (version
0.86 or above).
Notes
for users using other clients or old versions (version 0.86 or
below) BitComet clients.
Because
this function only enabled in the latest version of bitcomet, you
will see and have to download these padding files with other
clients.
