2 from bz2 import BZ2Decompressor
3 from zlib import decompressobj, MAX_WBITS
4 from gzip import FCOMMENT, FEXTRA, FHCRC, FNAME, FTEXT
5 from urlparse import urlparse
8 from twisted.python import log
9 from twisted.python.filepath import FilePath
10 from twisted.internet import defer, reactor
11 from twisted.trial import unittest
12 from twisted.web2 import stream
13 from twisted.web2.http import splitHostPort
15 from Hash import HashObject
17 aptpkg_dir='apt-packages'
19 DECOMPRESS_EXTS = ['.gz', '.bz2']
20 DECOMPRESS_FILES = ['release', 'sources', 'packages']
22 class ProxyFileStream(stream.SimpleStream):
23 """Saves a stream to a file while providing a new stream."""
25 def __init__(self, stream, outFile, hash, decompress = None, decFile = None):
26 """Initializes the proxy.
28 @type stream: C{twisted.web2.stream.IByteStream}
29 @param stream: the input stream to read from
30 @type outFile: C{twisted.python.FilePath}
31 @param outFile: the file to write to
32 @type hash: L{Hash.HashObject}
33 @param hash: the hash object to use for the file
34 @type decompress: C{string}
35 @param decompress: also decompress the file as this type
36 (currently only '.gz' and '.bz2' are supported)
37 @type decFile: C{twisted.python.FilePath}
38 @param decFile: the file to write the decompressed data to
41 self.outFile = outFile.open('w')
46 if decompress == ".gz":
48 self.gzfile = decFile.open('w')
49 self.gzdec = decompressobj(-MAX_WBITS)
50 elif decompress == ".bz2":
51 self.bz2file = decFile.open('w')
52 self.bz2dec = BZ2Decompressor()
53 self.length = self.stream.length
55 self.doneDefer = defer.Deferred()
58 """Close the output file."""
59 if not self.outFile.closed:
63 data_dec = self.gzdec.flush()
64 self.gzfile.write(data_dec)
71 self.doneDefer.callback(self.hash)
74 """Read some data from the stream."""
75 if self.outFile.closed:
78 data = self.stream.read()
79 if isinstance(data, defer.Deferred):
80 data.addCallbacks(self._write, self._done)
86 def _write(self, data):
87 """Write the stream data to the file and return it for others to use."""
92 self.outFile.write(data)
93 self.hash.update(data)
97 new_data = self._remove_gzip_header(data)
98 dec_data = self.gzdec.decompress(new_data)
100 dec_data = self.gzdec.decompress(data)
101 self.gzfile.write(dec_data)
103 dec_data = self.bz2dec.decompress(data)
104 self.bz2file.write(dec_data)
107 def _remove_gzip_header(self, data):
108 if data[:2] != '\037\213':
109 raise IOError, 'Not a gzipped file'
110 if ord(data[2]) != 8:
111 raise IOError, 'Unknown compression method'
113 # modtime = self.fileobj.read(4)
114 # extraflag = self.fileobj.read(1)
115 # os = self.fileobj.read(1)
119 # Read & discard the extra field, if present
121 xlen = xlen + 256*ord(data[11])
122 skip = skip + 2 + xlen
124 # Read and discard a null-terminated string containing the filename
126 if not data[skip] or data[skip] == '\000':
131 # Read and discard a null-terminated string containing a comment
133 if not data[skip] or data[skip] == '\000':
138 skip += 2 # Read & discard the 16-bit header CRC
142 """Clean everything up and return None to future reads."""
148 """Manages all requests for cached objects."""
150 def __init__(self, cache_dir, db, other_dirs = [], manager = None):
151 self.cache_dir = cache_dir
152 self.other_dirs = other_dirs
153 self.all_dirs = self.other_dirs[:]
154 self.all_dirs.insert(0, self.cache_dir)
156 self.manager = manager
159 # Init the database, remove old files
160 self.db.removeUntrackedFiles(self.all_dirs)
163 def scanDirectories(self):
164 """Scan the cache directories, hashing new and rehashing changed files."""
165 assert not self.scanning, "a directory scan is already under way"
166 self.scanning = self.all_dirs[:]
167 self._scanDirectories()
169 def _scanDirectories(self, result = None, walker = None):
170 # Need to start waling a new directory
172 # If there are any left, get them
174 log.msg('started scanning directory: %s' % self.scanning[0].path)
175 walker = self.scanning[0].walk()
177 log.msg('cache directory scan complete')
181 # Get the next file in the directory
183 except StopIteration:
184 # No files left, go to the next directory
185 log.msg('done scanning directory: %s' % self.scanning[0].path)
187 reactor.callLater(0, self._scanDirectories)
190 # If it's not a file ignore it
191 if not file.isfile():
192 log.msg('entering directory: %s' % file.path)
193 reactor.callLater(0, self._scanDirectories, None, walker)
196 # If it's already properly in the DB, ignore it
197 if self.db.isUnchanged(file):
198 log.msg('file is unchanged: %s' % file.path)
199 reactor.callLater(0, self._scanDirectories, None, walker)
202 # Don't hash files in the cache that are not in the DB
203 if self.scanning[0] == self.cache_dir:
204 log.msg('ignoring unknown cache file: %s' % file.path)
205 reactor.callLater(0, self._scanDirectories, None, walker)
209 log.msg('start hash checking file: %s' % file.path)
211 df = hash.hashInThread(file)
212 df.addBoth(self._doneHashing, file, walker)
213 df.addErrback(log.err)
215 def _doneHashing(self, result, file, walker):
217 if isinstance(result, HashObject):
218 log.msg('hash check of %s completed with hash: %s' % (file.path, result.hexdigest()))
220 if self.scanning[0] == self.cache_dir:
221 url = 'http:/' + file.path[len(self.cache_dir.path):]
222 new_hash = self.db.storeFile(file, result.digest())
223 df = self.manager.new_cached_file(file, result, new_hash, url, True)
225 reactor.callLater(0, self._scanDirectories, None, walker)
227 df.addBoth(self._scanDirectories, walker)
229 log.msg('hash check of %s failed' % file.path)
231 reactor.callLater(0, self._scanDirectories, None, walker)
233 def save_file(self, response, hash, url):
234 """Save a downloaded file to the cache and stream it."""
235 if response.code != 200:
236 log.msg('File was not found (%r): %s' % (response, url))
239 log.msg('Returning file: %s' % url)
241 parsed = urlparse(url)
242 destFile = self.cache_dir.preauthChild(parsed[1] + parsed[2])
243 log.msg('Saving returned %r byte file to cache: %s' % (response.stream.length, destFile.path))
245 if destFile.exists():
246 log.msg('File already exists, removing: %s' % destFile.path)
248 elif not destFile.parent().exists():
249 destFile.parent().makedirs()
251 root, ext = os.path.splitext(destFile.basename())
252 if root.lower() in DECOMPRESS_FILES and ext.lower() in DECOMPRESS_EXTS:
254 decFile = destFile.sibling(root)
255 log.msg('Decompressing to: %s' % decFile.path)
257 log.msg('File already exists, removing: %s' % decFile.path)
263 orig_stream = response.stream
264 response.stream = ProxyFileStream(orig_stream, destFile, hash, ext, decFile)
265 response.stream.doneDefer.addCallback(self._save_complete, url, destFile,
266 response.headers.getHeader('Last-Modified'),
268 response.stream.doneDefer.addErrback(self.save_error, url)
271 def _save_complete(self, hash, url, destFile, modtime = None, ext = None, decFile = None):
272 """Update the modification time and AptPackages."""
274 os.utime(destFile.path, (modtime, modtime))
276 os.utime(decFile.path, (modtime, modtime))
278 result = hash.verify()
279 if result or result is None:
281 log.msg('Hashes match: %s' % url)
283 log.msg('Hashed file to %s: %s' % (hash.hexdigest(), url))
285 new_hash = self.db.storeFile(destFile, hash.digest())
286 log.msg('now avaliable: %s' % (url))
289 self.manager.new_cached_file(destFile, hash, new_hash, url)
291 self.manager.new_cached_file(decFile, None, False, url[:-len(ext)])
293 log.msg("Hashes don't match %s != %s: %s" % (hash.hexexpected(), hash.hexdigest(), url))
298 def save_error(self, failure, url):
299 """An error has occurred in downloadign or saving the file."""
300 log.msg('Error occurred downloading %s' % url)
304 class TestMirrorManager(unittest.TestCase):
305 """Unit tests for the mirror manager."""
312 self.client = CacheManager(FilePath('/tmp/.apt-dht'))
315 for p in self.pending_calls: