+"""The main program code.
+
+@var DHT_PIECES: the maximum number of pieces to store with our contact info
+ in the DHT
+@var TORRENT_PIECES: the maximum number of pieces to store as a separate entry
+ in the DHT
+@var download_dir: the name of the directory to use for downloaded files
+
+"""
+
from binascii import b2a_hex
from urlparse import urlunparse
import os, re, sha
download_dir = 'cache'
class AptDHT:
+ """The main code object that does all of the work.
+
+ Contains all of the sub-components that do all the low-level work, and
+ coordinates communication between them.
+
+ @type cache_dir: L{twisted.python.filepath.FilePath}
+ @ivar cache_dir: the directory to use for storing all files
+ @type db: L{db.DB}
+ @ivar db: the database to use for tracking files and hashes
+ @type dht: L{interfaces.IDHT}
+ @ivar dht: the DHT instance to use
+ @type http_server: L{HTTPServer.TopLevel}
+ @ivar http_server: the web server that will handle all requests from apt
+ and from other peers
+ @type peers: L{PeerManager.PeerManager}
+ @ivar peers: the manager of all downloads from mirrors and other peers
+ @type mirrors: L{MirrorManager.MirrorManager}
+ @ivar mirrors: the manager of downloaded information about mirrors which
+ can be queried to get hashes from file names
+ @type cache: L{CacheManager.CacheManager}
+ @ivar cache: the manager of all downloaded files
+ @type my_contact: C{string}
+ @ivar my_contact: the 6-byte compact peer representation of this peer's
+ download information (IP address and port)
+ """
+
def __init__(self, dht):
+ """Initialize all the sub-components.
+
+ @type dht: L{interfaces.IDHT}
+ @param dht: the DHT instance to use
+ """
log.msg('Initializing the main apt_dht application')
self.cache_dir = FilePath(config.get('DEFAULT', 'cache_dir'))
if not self.cache_dir.child(download_dir).exists():
other_dirs = [FilePath(f) for f in config.getstringlist('DEFAULT', 'OTHER_DIRS')]
self.cache = CacheManager(self.cache_dir.child(download_dir), self.db, other_dirs, self)
self.my_contact = None
-
+
+ #{ DHT maintenance
def joinComplete(self, result):
+ """Complete the DHT join process and determine our download information.
+
+ Called by the DHT when the join has been completed with information
+ on the external IP address and port of this peer.
+ """
my_addr = findMyIPAddr(result,
config.getint(config.get('DEFAULT', 'DHT'), 'PORT'),
config.getboolean('DEFAULT', 'LOCAL_OK'))
reactor.callLater(60, self.refreshFiles)
def joinError(self, failure):
+ """Joining the DHT has failed."""
log.msg("joining DHT failed miserably")
log.err(failure)
raise RuntimeError, "IP address for this machine could not be found"
else:
reactor.callLater(60, self.refreshFiles)
- def check_freshness(self, req, path, modtime, resp):
- log.msg('Checking if %s is still fresh' % path)
- d = self.peers.get('', path, method = "HEAD", modtime = modtime)
- d.addCallback(self.check_freshness_done, req, path, resp)
+ #{ Main workflow
+ def check_freshness(self, req, url, modtime, resp):
+ """Send a HEAD to the mirror to check if the response from the cache is still valid.
+
+ @type req: L{twisted.web2.http.Request}
+ @param req: the initial request sent to the HTTP server by apt
+ @param url: the URI of the actual mirror request
+ @type modtime: C{int}
+ @param modtime: the modified time of the cached file (seconds since epoch)
+ @type resp: L{twisted.web2.http.Response}
+ @param resp: the response from the cache to be sent to apt
+ @rtype: L{twisted.internet.defer.Deferred}
+ @return: a deferred that will be called back with the correct response
+ """
+ log.msg('Checking if %s is still fresh' % url)
+ d = self.peers.get('', url, method = "HEAD", modtime = modtime)
+ d.addCallback(self.check_freshness_done, req, url, resp)
return d
- def check_freshness_done(self, resp, req, path, orig_resp):
+ def check_freshness_done(self, resp, req, url, orig_resp):
+ """Process the returned response from the mirror.
+
+ @type resp: L{twisted.web2.http.Response}
+ @param resp: the response from the mirror to the HEAD request
+ @type req: L{twisted.web2.http.Request}
+ @param req: the initial request sent to the HTTP server by apt
+ @param url: the URI of the actual mirror request
+ @type orig_resp: L{twisted.web2.http.Response}
+ @param orig_resp: the response from the cache to be sent to apt
+ """
if resp.code == 304:
- log.msg('Still fresh, returning: %s' % path)
+ log.msg('Still fresh, returning: %s' % url)
return orig_resp
else:
- log.msg('Stale, need to redownload: %s' % path)
- return self.get_resp(req, path)
+ log.msg('Stale, need to redownload: %s' % url)
+ return self.get_resp(req, url)
- def get_resp(self, req, path):
+ def get_resp(self, req, url):
+ """Lookup a hash for the file in the local mirror info.
+
+ Starts the process of getting a response to an uncached apt request.
+
+ @type req: L{twisted.web2.http.Request}
+ @param req: the initial request sent to the HTTP server by apt
+ @param url: the URI of the actual mirror request
+ @rtype: L{twisted.internet.defer.Deferred}
+ @return: a deferred that will be called back with the response
+ """
d = defer.Deferred()
- log.msg('Trying to find hash for %s' % path)
- findDefer = self.mirrors.findHash(path)
+ log.msg('Trying to find hash for %s' % url)
+ findDefer = self.mirrors.findHash(url)
findDefer.addCallbacks(self.findHash_done, self.findHash_error,
- callbackArgs=(req, path, d), errbackArgs=(req, path, d))
+ callbackArgs=(req, url, d), errbackArgs=(req, url, d))
findDefer.addErrback(log.err)
return d
- def findHash_error(self, failure, req, path, d):
+ def findHash_error(self, failure, req, url, d):
+ """Process the error in hash lookup by returning an empty L{HashObject}."""
log.err(failure)
- self.findHash_done(HashObject(), req, path, d)
+ self.findHash_done(HashObject(), req, url, d)
+
+ def findHash_done(self, hash, req, url, d):
+ """Use the returned hash to lookup the file in the cache.
+
+ If the hash was not found, the workflow skips down to download from
+ the mirror (L{lookupHash_done}).
- def findHash_done(self, hash, req, path, d):
+ @type hash: L{Hash.HashObject}
+ @param hash: the hash object containing the expected hash for the file
+ """
if hash.expected() is None:
- log.msg('Hash for %s was not found' % path)
- self.lookupHash_done([], hash, path, d)
+ log.msg('Hash for %s was not found' % url)
+ self.lookupHash_done([], hash, url, d)
else:
- log.msg('Found hash %s for %s' % (hash.hexexpected(), path))
+ log.msg('Found hash %s for %s' % (hash.hexexpected(), url))
# Lookup hash in cache
locations = self.db.lookupHash(hash.expected(), filesOnly = True)
- self.getCachedFile(hash, req, path, d, locations)
+ self.getCachedFile(hash, req, url, d, locations)
- def getCachedFile(self, hash, req, path, d, locations):
+ def getCachedFile(self, hash, req, url, d, locations):
+ """Try to return the file from the cache, otherwise move on to a DHT lookup.
+
+ @type locations: C{list} of C{dictionary}
+ @param locations: the files in the cache that match the hash,
+ the dictionary contains a key 'path' whose value is a
+ L{twisted.python.filepath.FilePath} object for the file.
+ """
if not locations:
- log.msg('Failed to return file from cache: %s' % path)
- self.lookupHash(hash, path, d)
+ log.msg('Failed to return file from cache: %s' % url)
+ self.lookupHash(hash, url, d)
return
# Get the first possible location from the list
# Get it's response
resp = static.File(file.path).renderHTTP(req)
if isinstance(resp, defer.Deferred):
- resp.addBoth(self._getCachedFile, hash, req, path, d, locations)
+ resp.addBoth(self._getCachedFile, hash, req, url, d, locations)
else:
- self._getCachedFile(resp, hash, req, path, d, locations)
+ self._getCachedFile(resp, hash, req, url, d, locations)
- def _getCachedFile(self, resp, hash, req, path, d, locations):
+ def _getCachedFile(self, resp, hash, req, url, d, locations):
+ """Check the returned response to be sure it is valid."""
if isinstance(resp, failure.Failure):
log.msg('Got error trying to get cached file')
log.err()
# Try the next possible location
- self.getCachedFile(hash, req, path, d, locations)
+ self.getCachedFile(hash, req, url, d, locations)
return
log.msg('Cached response: %r' % resp)
d.callback(resp)
else:
# Try the next possible location
- self.getCachedFile(hash, req, path, d, locations)
+ self.getCachedFile(hash, req, url, d, locations)
- def lookupHash(self, hash, path, d):
- log.msg('Looking up hash in DHT for file: %s' % path)
+ def lookupHash(self, hash, url, d):
+ """Lookup the hash in the DHT."""
+ log.msg('Looking up hash in DHT for file: %s' % url)
key = hash.expected()
lookupDefer = self.dht.getValue(key)
- lookupDefer.addCallback(self.lookupHash_done, hash, path, d)
+ lookupDefer.addCallback(self.lookupHash_done, hash, url, d)
- def lookupHash_done(self, values, hash, path, d):
+ def lookupHash_done(self, values, hash, url, d):
+ """Start the download of the file.
+
+ The download will be from peers if the DHT lookup succeeded, or
+ from the mirror otherwise.
+
+ @type values: C{list} of C{dictionary}
+ @param values: the returned values from the DHT containing peer
+ download information
+ """
if not values:
- log.msg('Peers for %s were not found' % path)
- getDefer = self.peers.get(hash, path)
- getDefer.addCallback(self.cache.save_file, hash, path)
- getDefer.addErrback(self.cache.save_error, path)
+ log.msg('Peers for %s were not found' % url)
+ getDefer = self.peers.get(hash, url)
+ getDefer.addCallback(self.cache.save_file, hash, url)
+ getDefer.addErrback(self.cache.save_error, url)
getDefer.addCallbacks(d.callback, d.errback)
else:
- log.msg('Found peers for %s: %r' % (path, values))
+ log.msg('Found peers for %s: %r' % (url, values))
# Download from the found peers
- getDefer = self.peers.get(hash, path, values)
- getDefer.addCallback(self.check_response, hash, path)
- getDefer.addCallback(self.cache.save_file, hash, path)
- getDefer.addErrback(self.cache.save_error, path)
+ getDefer = self.peers.get(hash, url, values)
+ getDefer.addCallback(self.check_response, hash, url)
+ getDefer.addCallback(self.cache.save_file, hash, url)
+ getDefer.addErrback(self.cache.save_error, url)
getDefer.addCallbacks(d.callback, d.errback)
- def check_response(self, response, hash, path):
+ def check_response(self, response, hash, url):
+ """Check the response from peers, and download from the mirror if it is not."""
if response.code < 200 or response.code >= 300:
- log.msg('Download from peers failed, going to direct download: %s' % path)
- getDefer = self.peers.get(hash, path)
+ log.msg('Download from peers failed, going to direct download: %s' % url)
+ getDefer = self.peers.get(hash, url)
return getDefer
return response
def new_cached_file(self, file_path, hash, new_hash, url = None, forceDHT = False):
- """Add a newly cached file to the appropriate places.
+ """Add a newly cached file to the mirror info and/or the DHT.
If the file was downloaded, set url to the path it was downloaded for.
Doesn't add a file to the DHT unless a hash was found for it
(but does add it anyway if forceDHT is True).
+
+ @type file_path: L{twisted.python.filepath.FilePath}
+ @param file_path: the location of the file in the local cache
+ @type hash: L{Hash.HashObject}
+ @param hash: the original (expected) hash object containing also the
+ hash of the downloaded file
+ @type new_hash: C{boolean}
+ @param new_hash: whether the has was new to this peer, and so should
+ be added to the DHT
+ @type url: C{string}
+ @param url: the URI of the location of the file in the mirror
+ (optional, defaults to not adding the file to the mirror info)
+ @type forceDHT: C{boolean}
+ @param forceDHT: whether to force addition of the file to the DHT
+ even if the hash was not found in a mirror
+ (optional, defaults to False)
"""
if url:
self.mirrors.updatedFile(url, file_path)
return None
def store(self, hash):
- """Add a file to the DHT."""
+ """Add a key/value pair for the file to the DHT.
+
+ Sets the key and value from the hash information, and tries to add
+ it to the DHT.
+ """
key = hash.digest()
value = {'c': self.my_contact}
pieces = hash.pieceDigests()
+
+ # Determine how to store any piece data
if len(pieces) <= 1:
pass
elif len(pieces) <= DHT_PIECES:
+ # Short enough to be stored with our peer contact info
value['t'] = {'t': ''.join(pieces)}
elif len(pieces) <= TORRENT_PIECES:
+ # Short enough to be stored in a separate key in the DHT
s = sha.new().update(''.join(pieces))
value['h'] = s.digest()
else:
+ # Too long, must be served up by our peer HTTP server
s = sha.new().update(''.join(pieces))
value['l'] = s.digest()
+
storeDefer = self.dht.storeValue(key, value)
storeDefer.addCallback(self.store_done, hash)
return storeDefer
def store_done(self, result, hash):
+ """Add a key/value pair for the pieces of the file to the DHT (if necessary)."""
log.msg('Added %s to the DHT: %r' % (hash.hexdigest(), result))
pieces = hash.pieceDigests()
if len(pieces) > DHT_PIECES and len(pieces) <= TORRENT_PIECES:
+ # Add the piece data key and value to the DHT
s = sha.new().update(''.join(pieces))
key = s.digest()
value = {'t': ''.join(pieces)}
+
storeDefer = self.dht.storeValue(key, value)
storeDefer.addCallback(self.store_torrent_done, key)
return storeDefer
return result
def store_torrent_done(self, result, key):
+ """Adding the file to the DHT is complete, and so is the workflow."""
log.msg('Added torrent string %s to the DHT: %r' % (b2ahex(key), result))
return result
\ No newline at end of file
projects / quix0rs-apt-p2p.git / commitdiff