X-Git-Url: https://git.mxchange.org/?p=quix0rs-apt-p2p.git;a=blobdiff_plain;f=TODO;h=bd8283c904d6ed372c9a84136ce204422bb6e183;hp=dd9524a40f3ce417eba51814d8430bb5d34372b1;hb=21f3067f2e5f694c696835f5eceab0eba5c3d479;hpb=136c82d6c138402e93bdefb499aed967ba059385

diff --git a/TODO b/TODO
index dd9524a..bd8283c 100644
--- a/TODO
+++ b/TODO
@@ -1,9 +1,51 @@
-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.
+Rotate DNS entries for mirrors more reliably.
+
+Currently the mirrors are accessed by DNS name, which can cause some
+issues when there are mirror differences and the DNS gets rotated.
+Instead, the HTTP Downloader should handle DNS lookups itself, store
+the resulting addresses, and send requests to IP addresses. If there
+is an error from the mirror (hash check or 404 response), the next IP
+address in the rotation should be used.
+
+
+Use GPG signatures as a hash for files.
+
+A detached GPG signature, such as is found in Release.gpg, can be used
+as a hash for the file. This hash can be used to verify the file when
+it is downloaded, and a shortened version can be added to the DHT to
+look up peers for the file. To get the hash into a binary form from
+the ascii-armored detached file, use the command
+'gpg --no-options --no-default-keyring --output - --dearmor -'. The
+hash should be stored as the reverse of the resulting binary string,
+as the bytes at the beginning are headers that are the same for most
+signatures. That way the shortened hash stored in the DHT will have a
+better chance of being unique and being stored on different peers. To
+verify a file, first the binary hash must be re-reversed, armored, and
+written to a temporary file with the command
+'gpg --no-options --no-default-keyring --output $tempfile --enarmor -'.
+Then the incoming file can be verified with the command
+'gpg --no-options --no-default-keyring --keyring /etc/apt/trusted.gpg
+--verify $tempfile -'.
+
+All communication with the command-line gpg should be done using pipes
+and the python module python-gnupginterface. There needs to be a new
+module for GPG verification and hashing, which will make this easier.
+In particular, it would need to support hashlib-like functionality
+such as new(), update(), and digest(). Note that the verification
+would not involve signing the file again and comparing the signatures,
+as this is not possible. Instead, the verify() function would have to
+behave differently for GPG hashes, and check that the verification
+resulted in a VALIDSIG. CAUTION: the detached signature can have a
+variable length, though it seems to be usually 65 bytes, 64 bytes has
+also been observed.
+
+
+Consider what happens when multiple requests for a file are received.
+
+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.
@@ -15,6 +57,42 @@ distributions. They need to be dealt with properly by
 adding them to the tracking done by the AptPackages module.
 
 
+Improve the estimation of the total number of nodes
+
+The current total nodes estimation is based on the number of buckets.
+A better way is to look at the average inter-node spacing for the K
+closest nodes after a find_node/value completes. Be sure to measure
+the inter-node spacing in log2 space to dampen any ill effects. This
+can be used in the formula:
+        nodes = 2^160 / 2^(average of log2 spacing)
+The average should also be saved using an exponentially weighted
+moving average (of the log2 distance) over separate find_node/value
+actions to get a better calculation over time.
+
+
+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.
 
 Instead of downloading full package files when a previous version of