+"""Serve local requests from apt and remote requests from peers."""
+
from urllib import unquote_plus
+from binascii import b2a_hex
from twisted.python import log
from twisted.internet import defer
-from twisted.web2 import server, http, resource, channel
+from twisted.web2 import server, http, resource, channel, stream
from twisted.web2 import static, http_headers, responsecode
+from policies import ThrottlingFactory
+from apt_dht_Khashmir.bencode import bencode
+
class FileDownloader(static.File):
+ """Modified to make it suitable for apt requests.
+
+ Tries to find requests in the cache. Found files are first checked for
+ freshness before being sent. Requests for unfound and stale files are
+ forwarded to the main program for downloading.
+
+ @type manager: L{apt_dht.AptDHT}
+ @ivar manager: the main program to query
+ """
def __init__(self, path, manager, defaultType="text/plain", ignoredExts=(), processors=None, indexNames=None):
self.manager = manager
return self.__class__(path, self.manager, self.defaultType, self.ignoredExts,
self.processors, self.indexNames[:])
+class FileUploaderStream(stream.FileStream):
+ """Modified to make it suitable for streaming to peers.
+
+ Streams the file is small chunks to make it easier to throttle the
+ streaming to peers.
+
+ @ivar CHUNK_SIZE: the size of chunks of data to send at a time
+ """
+
+ CHUNK_SIZE = 4*1024
+
+ def read(self, sendfile=False):
+ if self.f is None:
+ return None
+
+ length = self.length
+ if length == 0:
+ self.f = None
+ return None
+ # Remove the SendFileBuffer and mmap use, just use string reads and writes
+
+ readSize = min(length, self.CHUNK_SIZE)
+
+ self.f.seek(self.start)
+ b = self.f.read(readSize)
+ bytesRead = len(b)
+ if not bytesRead:
+ raise RuntimeError("Ran out of data reading file %r, expected %d more bytes" % (self.f, length))
+ else:
+ self.length -= bytesRead
+ self.start += bytesRead
+ return b
+
+
+class FileUploader(static.File):
+ """Modified to make it suitable for peer requests.
+
+ Uses the modified L{FileUploaderStream} to stream the file for throttling,
+ and doesn't do any listing of directory contents.
+ """
+
+ def render(self, req):
+ if not self.fp.exists():
+ return responsecode.NOT_FOUND
+
+ if self.fp.isdir():
+ # Don't try to render a directory listing
+ return responsecode.NOT_FOUND
+
+ try:
+ f = self.fp.open()
+ except IOError, e:
+ import errno
+ if e[0] == errno.EACCES:
+ return responsecode.FORBIDDEN
+ elif e[0] == errno.ENOENT:
+ return responsecode.NOT_FOUND
+ else:
+ raise
+
+ response = http.Response()
+ # Use the modified FileStream
+ response.stream = FileUploaderStream(f, 0, self.fp.getsize())
+
+ for (header, value) in (
+ ("content-type", self.contentType()),
+ ("content-encoding", self.contentEncoding()),
+ ):
+ if value is not None:
+ response.headers.setHeader(header, value)
+
+ return response
+
class TopLevel(resource.Resource):
+ """The HTTP server for all requests, both from peers and apt.
+
+ @type directory: L{twisted.python.filepath.FilePath}
+ @ivar directory: the directory to check for cached files
+ @type db: L{db.DB}
+ @ivar db: the database to use for looking up files and hashes
+ @type manager: L{apt_dht.AptDHT}
+ @ivar manager: the main program object to send requests to
+ @type factory: L{twisted.web2.channel.HTTPFactory} or L{policies.ThrottlingFactory}
+ @ivar factory: the factory to use to server HTTP requests
+
+ """
+
addSlash = True
def __init__(self, directory, db, manager):
+ """Initialize the instance.
+
+ @type directory: L{twisted.python.filepath.FilePath}
+ @param directory: the directory to check for cached files
+ @type db: L{db.DB}
+ @param db: the database to use for looking up files and hashes
+ @type manager: L{apt_dht.AptDHT}
+ @param manager: the main program object to send requests to
+ """
self.directory = directory
self.db = db
self.manager = manager
self.factory = None
def getHTTPFactory(self):
+ """Initialize and get the factory for this HTTP server."""
if self.factory is None:
self.factory = channel.HTTPFactory(server.Site(self),
**{'maxPipeline': 10,
'betweenRequestsTimeOut': 60})
+ self.factory = ThrottlingFactory(self.factory, writeLimit = 30*1024)
return self.factory
def render(self, ctx):
+ """Render a web page with descriptive statistics."""
return http.Response(
200,
{'content-type': http_headers.MimeType('text', 'html')},
<p>TODO: eventually some stats will be shown here.</body></html>""")
def locateChild(self, request, segments):
+ """Process the incoming request."""
log.msg('Got HTTP request for %s from %s' % (request.uri, request.remoteAddr))
name = segments[0]
+
+ # If the request is for a shared file (from a peer)
if name == '~':
if len(segments) != 2:
log.msg('Got a malformed request from %s' % request.remoteAddr)
return None, ()
+
+ # Find the file in the database
hash = unquote_plus(segments[1])
files = self.db.lookupHash(hash)
if files:
- log.msg('Sharing %s with %s' % (files[0]['path'].path, request.remoteAddr))
- return static.File(files[0]['path'].path), ()
+ # If it is a file, return it
+ if 'path' in files[0]:
+ log.msg('Sharing %s with %s' % (files[0]['path'].path, request.remoteAddr))
+ return FileUploader(files[0]['path'].path), ()
+ else:
+ # It's not for a file, but for a piece string, so return that
+ log.msg('Sending torrent string %s to %s' % (b2a_hex(hash), request.remoteAddr))
+ return static.Data(bencode({'t': files[0]['pieces']}), 'application/x-bencoded'), ()
else:
log.msg('Hash could not be found in database: %s' % hash)
-
+
+ # Only local requests (apt) get past this point
if request.remoteAddr.host != "127.0.0.1":
log.msg('Blocked illegal access to %s from %s' % (request.uri, request.remoteAddr))
return None, ()
if len(name) > 1:
+ # It's a request from apt
return FileDownloader(self.directory.path, self.manager), segments[0:]
else:
+ # Will render the statistics page
return self, ()
log.msg('Got a malformed request for "%s" from %s' % (request.uri, request.remoteAddr))
return None, ()
if __name__ == '__builtin__':
- # Running from twistd -y
- t = TopLevel('/home', None)
- t.setDirectories({'~1': '/tmp', '~2': '/var/log'})
+ # Running from twistd -ny HTTPServer.py
+ # Then test with:
+ # wget -S 'http://localhost:18080/~/whatever'
+ # wget -S 'http://localhost:18080/~/pieces'
+
+ import os.path
+ from twisted.python.filepath import FilePath
+
+ class DB:
+ def lookupHash(self, hash):
+ if hash == 'pieces':
+ return [{'pieces': 'abcdefghij0123456789\xca\xec\xb8\x0c\x00\xe7\x07\xf8~])\x8f\x9d\xe5_B\xff\x1a\xc4!'}]
+ return [{'path': FilePath(os.path.expanduser('~/school/optout'))}]
+
+ t = TopLevel(FilePath(os.path.expanduser('~')), DB(), None)
factory = t.getHTTPFactory()
# Standard twisted application Boilerplate