commit ac694d3a98ce1e56c674893f8006efe785eb41c9 Author: Damian Johnson atagar@torproject.org Date: Tue Jul 16 09:16:06 2013 -0700

Implementing get_server_descriptors() method

Implementing our first downloader method and added an ONLINE integ test. Initially I did a get_microdescriptors() method but turns out that tor didn't implement what we need...

https://trac.torproject.org/9271 --- stem/descriptor/remote.py | 47 +++++++++++++++++++++++++++++++-------- test/integ/descriptor/remote.py | 30 +++++++++++++++++++++++++ 2 files changed, 68 insertions(+), 9 deletions(-)

diff --git a/stem/descriptor/remote.py b/stem/descriptor/remote.py index 88e3258..a4b21d4 100644 --- a/stem/descriptor/remote.py +++ b/stem/descriptor/remote.py @@ -80,16 +80,20 @@ class Query(object):

:var list endpoints: (address, dirport) tuples of the authority or mirror we're querying, this uses authorities if undefined - :var int retries: number of times to attempt the request if it fails + :var int retries: number of times to attempt the request if downloading it + fails :var bool fall_back_to_authority: when retrying request issues the last request to a directory authority if **True**

:var Exception error: exception if a problem occured :var bool is_done: flag that indicates if our request has finished + :var str download_url: last url used to download the descriptor, this is + unset until we've actually made a download attempt

:var float start_time: unix timestamp when we first started running :var float timeout: duration before we'll time out our request - :var float runtime: time our query took, this is **None** if it's not yet finished + :var float runtime: time our query took, this is **None** if it's not yet + finished """

def __init__(self, resource, descriptor_type, endpoints = None, retries = 2, fall_back_to_authority = True, timeout = None, start = True): @@ -102,6 +106,7 @@ class Query(object):

self.error = None self.is_done = False + self.download_url = None

self.start_time = None self.timeout = timeout @@ -183,6 +188,8 @@ class Query(object): for desc in self._results: yield desc except ValueError as exc: + # encountered a parsing error + self.error = exc

if not suppress: @@ -195,10 +202,10 @@ class Query(object): def _download_descriptors(self, retries): try: use_authority = retries == 0 and self.fall_back_to_authority - resource_url = self.pick_url(use_authority) + self.download_url = self.pick_url(use_authority)

self.start_time = time.time() - response = urllib2.urlopen(resource_url, timeout = self.timeout) + response = urllib2.urlopen(self.download_url, timeout = self.timeout) self.runtime = time.time() - self.start_time

# This sucks. We need to read the full response into memory before @@ -209,15 +216,15 @@ class Query(object): response = io.BytesIO(response.read().strip())

self._results = stem.descriptor.parse_file(response, self.descriptor_type) - log.trace("Descriptors retrieved from '%s' in %0.2fs" % (resource_url, self.runtime)) + log.trace("Descriptors retrieved from '%s' in %0.2fs" % (self.download_url, self.runtime)) except: exc = sys.exc_info()[1]

if retries > 0: - log.debug("Unable to download descriptors from '%s' (%i retries remaining): %s" % (resource_url, retries, exc)) + log.debug("Unable to download descriptors from '%s' (%i retries remaining): %s" % (self.download_url, retries, exc)) return self._download_descriptors(retries - 1) else: - log.debug("Unable to download descriptors from '%s': %s" % (resource_url, exc)) + log.debug("Unable to download descriptors from '%s': %s" % (self.download_url, exc)) self.error = exc finally: self.is_done = True @@ -242,14 +249,36 @@ class DescriptorDownloader(object): request to a directory authority if **True** """

- def __init__(self, retries = 2, timeout = None, start_when_requested = True, fall_back_to_authority = True): + def __init__(self, retries = 2, fall_back_to_authority = True, timeout = None, start_when_requested = True): self.retries = retries self.timeout = timeout self.start_when_requested = start_when_requested self.fall_back_to_authority = fall_back_to_authority self._endpoints = DIRECTORY_AUTHORITIES.values()

- def _query(self, resource, descriptor_type, retries): + def get_server_descriptors(self, fingerprints = None): + """ + Provides the server descriptors with the given fingerprints. If no + fingerprints are provided then this returns all descriptors in the present + consensus. + + :param str,list fingerprints: fingerprint or list of fingerprints to be + retrieved, gets all descriptors if **None** + + :returns: :class:`~stem.descriptor.remote.Query` for the server descriptors + """ + + resource = '/tor/server/all' + + if fingerprints: + if isinstance(fingerprints, str): + resource = '/tor/server/fp/%s' % fingerprints + else: + resource = '/tor/server/fp/%s' % '+'.join(fingerprints) + + return self._query(resource, 'server-descriptor 1.0') + + def _query(self, resource, descriptor_type): """ Issues a request for the given resource. """ diff --git a/test/integ/descriptor/remote.py b/test/integ/descriptor/remote.py index 8509556..6e1f426 100644 --- a/test/integ/descriptor/remote.py +++ b/test/integ/descriptor/remote.py @@ -44,3 +44,33 @@ class TestDescriptorReader(unittest.TestCase): self.assertEqual(1, len(descriptors)) self.assertEqual('moria1', descriptors[0].nickname)

+ def test_get_server_descriptors(self): + """ + Exercises the downloader's get_server_descriptors() method. + """ + + downloader = stem.descriptor.remote.DescriptorDownloader() + + # Fetch a single descriptor and a batch. I'd love to also exercise + # retrieving all descriptors, but that adds roughly a minute to the runtime + # of this test and adds an appreciable load to directory authorities. + + single_query = downloader.get_server_descriptors('9695DFC35FFEB861329B9F1AB04C46397020CE31') + + multiple_query = downloader.get_server_descriptors([ + '9695DFC35FFEB861329B9F1AB04C46397020CE31', + '847B1F850344D7876491A54892F904934E4EB85D', + ]) + + # Explicitly running the queries so they'll provide a useful error if + # unsuccessful. + + single_query.run() + multiple_query.run() + + single_query_results = list(single_query) + self.assertEqual(1, len(single_query_results)) + self.assertEqual('moria1', single_query_results[0].nickname) + + self.assertEqual(2, len(list(multiple_query))) +