-Add statistics gathering to the peer downloading.
+Consider what happens when multiple requests for a file are received.
-Statistics are needed of how much has been uploaded, downloaded from
-peers, and downloaded from mirrors.
-
-
-Add all cache files to the database.
-
-All files in the cache should be added to the database, so that they can
-be checked to make sure nothing has happened to them. The database would
-then need a flag to indicate files that are hashed and available, but
-that shouldn't be added to the DHT.
+When another request comes in for a file already being downloaded,
+the new request should wait for the old one to finish. This should
+also be done for multiple requests for peer downloads of files with
+the same hash.
Packages.diff files need to be considered.
adding them to the tracking done by the AptPackages module.
-Retransmit DHT requests before timeout occurs.
-
-Currently, only a single transmission to a peer is ever attempted. If
-that request is lost, a timeout will occur after 20 seconds, the peer
-will be declared unreachable and the action will move on to the next
-peer. Instead, try to resend the request periodically using exponential
-backoff to make sure that lost packets don't delay the action so much.
-For example, send the request, wait 2 seconds and send again, wait 4
-seconds and send again, wait 8 seconds (14 seconds have now passed) and
-then declare the host unreachable. The same TID should be used in each
-retransmission, so receiving multiple responses should not be a problem
-as the extra ones will be ignored.
-
-
-PeerManager needs to download large files from multiple peers.
-
-The PeerManager currently chooses a peer at random from the list of
-possible peers, and downloads the entire file from there. This needs to
-change if both a) the file is large (more than 512 KB), and b) there are
-multiple peers with the file. The PeerManager should then break up the
-large file into multiple pieces of size < 512 KB, and then send requests
-to multiple peers for these pieces.
-
-This can cause a problem with hash checking the returned data, as hashes
-for the pieces are not known. Any file that fails a hash check should be
-downloaded again, with each piece being downloaded from different peers
-than it was previously. The peers are shifted by 1, so that if a peers
-previously downloaded piece i, it now downloads piece i+1, and the first
-piece is downloaded by the previous downloader of the last piece, or
-preferably a previously unused peer. As each piece is downloaded the
-running hash of the file should be checked to determine the place at
-which the file differs from the previous download.
-
-If the hash check then passes, then the peer who originally provided the
-bad piece can be assessed blame for the error. Otherwise, the peer who
-originally provided the piece is probably at fault, since he is now
-providing a later piece. This doesn't work if the differing piece is the
-first piece, in which case it is downloaded from a 3rd peer, with
-consensus revealing the misbehaving peer.
+Improve the downloaded and uploaded data measurements.
+
+There are 2 places that this data is measured: for statistics, and for
+limiting the upload bandwidth. They both have deficiencies as they
+sometimes miss the headers or the requests sent out. The upload
+bandwidth calculation only considers the stream in the upload and not
+the headers sent, and it also doesn't consider the upload bandwidth
+from requesting downloads from peers (though that may be a good thing).
+The statistics calculations for downloads include the headers of
+downloaded files, but not the requests received from peers for upload
+files. The statistics for uploaded data only includes the files sent
+and not the headers, and also misses the requests for downloads sent to
+other peers.
+
+
+Rehash changed files instead of removing them.
+
+When the modification time of a file changes but the size does not,
+the file could be rehased to verify it is the same instead of
+automatically removing it. The DB would have to be modified to return
+deferred's for a lot of its functions.
Consider storing deltas of packages.
projects / quix0rs-apt-p2p.git / blobdiff