lib/bup/client.py

   1 import re, struct, errno, time, zlib
   2 from bup import git, ssh
   3 from bup.helpers import *
   4
   5 bwlimit = None
   6
   7
   8 class ClientError(Exception):
   9     pass
  10
  11
  12 def _raw_write_bwlimit(f, buf, bwcount, bwtime):
  13     if not bwlimit:
  14         f.write(buf)
  15         return (len(buf), time.time())
  16     else:
  17         # We want to write in reasonably large blocks, but not so large that
  18         # they're likely to overflow a router's queue.  So our bwlimit timing
  19         # has to be pretty granular.  Also, if it takes too long from one
  20         # transmit to the next, we can't just make up for lost time to bring
  21         # the average back up to bwlimit - that will risk overflowing the
  22         # outbound queue, which defeats the purpose.  So if we fall behind
  23         # by more than one block delay, we shouldn't ever try to catch up.
  24         for i in xrange(0,len(buf),4096):
  25             now = time.time()
  26             next = max(now, bwtime + 1.0*bwcount/bwlimit)
  27             time.sleep(next-now)
  28             sub = buf[i:i+4096]
  29             f.write(sub)
  30             bwcount = len(sub)  # might be less than 4096
  31             bwtime = next
  32         return (bwcount, bwtime)
  33
  34
  35 def parse_remote(remote):
  36     protocol = r'([a-z]+)://'
  37     host = r'(?P<sb>\[)?((?(sb)[0-9a-f:]+|[^:/]+))(?(sb)\])'
  38     port = r'(?::(\d+))?'
  39     path = r'(/.*)?'
  40     url_match = re.match(
  41             '%s(?:%s%s)?%s' % (protocol, host, port, path), remote, re.I)
  42     if url_match:
  43         if not url_match.group(1) in ('ssh', 'bup', 'file'):
  44             raise ClientError, 'unexpected protocol: %s' % url_match.group(1)
  45         return url_match.group(1,3,4,5)
  46     else:
  47         rs = remote.split(':', 1)
  48         if len(rs) == 1 or rs[0] in ('', '-'):
  49             return 'file', None, None, rs[-1]
  50         else:
  51             return 'ssh', rs[0], None, rs[1]
  52
  53
  54 class Client:
  55     def __init__(self, remote, create=False):
  56         self._busy = self.conn = None
  57         self.sock = self.p = self.pout = self.pin = None
  58         is_reverse = os.environ.get('BUP_SERVER_REVERSE')
  59         if is_reverse:
  60             assert(not remote)
  61             remote = '%s:' % is_reverse
  62         (self.protocol, self.host, self.port, self.dir) = parse_remote(remote)
  63         self.cachedir = git.repo('index-cache/%s'
  64                                  % re.sub(r'[^@\w]', '_',
  65                                           "%s:%s" % (self.host, self.dir)))
  66         if is_reverse:
  67             self.pout = os.fdopen(3, 'rb')
  68             self.pin = os.fdopen(4, 'wb')
  69             self.conn = Conn(self.pout, self.pin)
  70         else:
  71             if self.protocol in ('ssh', 'file'):
  72                 try:
  73                     # FIXME: ssh and file shouldn't use the same module
  74                     self.p = ssh.connect(self.host, self.port, 'server')
  75                     self.pout = self.p.stdout
  76                     self.pin = self.p.stdin
  77                     self.conn = Conn(self.pout, self.pin)
  78                 except OSError as e:
  79                     raise ClientError, 'connect: %s' % e, sys.exc_info()[2]
  80             elif self.protocol == 'bup':
  81                 self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  82                 self.sock.connect((self.host, atoi(self.port) or 1982))
  83                 self.sockw = self.sock.makefile('wb')
  84                 self.conn = DemuxConn(self.sock.fileno(), self.sockw)
  85         if self.dir:
  86             self.dir = re.sub(r'[\r\n]', ' ', self.dir)
  87             if create:
  88                 self.conn.write('init-dir %s\n' % self.dir)
  89             else:
  90                 self.conn.write('set-dir %s\n' % self.dir)
  91             self.check_ok()
  92         self.sync_indexes()
  93
  94     def __del__(self):
  95         try:
  96             self.close()
  97         except IOError as e:
  98             if e.errno == errno.EPIPE:
  99                 pass
 100             else:
 101                 raise
 102
 103     def close(self):
 104         if self.conn and not self._busy:
 105             self.conn.write('quit\n')
 106         if self.pin:
 107             self.pin.close()
 108         if self.sock and self.sockw:
 109             self.sockw.close()
 110             self.sock.shutdown(socket.SHUT_WR)
 111         if self.conn:
 112             self.conn.close()
 113         if self.pout:
 114             self.pout.close()
 115         if self.sock:
 116             self.sock.close()
 117         if self.p:
 118             self.p.wait()
 119             rv = self.p.wait()
 120             if rv:
 121                 raise ClientError('server tunnel returned exit code %d' % rv)
 122         self.conn = None
 123         self.sock = self.p = self.pin = self.pout = None
 124
 125     def check_ok(self):
 126         if self.p:
 127             rv = self.p.poll()
 128             if rv != None:
 129                 raise ClientError('server exited unexpectedly with code %r'
 130                                   % rv)
 131         try:
 132             return self.conn.check_ok()
 133         except Exception as e:
 134             raise ClientError, e, sys.exc_info()[2]
 135
 136     def check_busy(self):
 137         if self._busy:
 138             raise ClientError('already busy with command %r' % self._busy)
 139
 140     def ensure_busy(self):
 141         if not self._busy:
 142             raise ClientError('expected to be busy, but not busy?!')
 143
 144     def _not_busy(self):
 145         self._busy = None
 146
 147     def sync_indexes(self):
 148         self.check_busy()
 149         conn = self.conn
 150         mkdirp(self.cachedir)
 151         # All cached idxs are extra until proven otherwise
 152         extra = set()
 153         for f in os.listdir(self.cachedir):
 154             debug1('%s\n' % f)
 155             if f.endswith('.idx'):
 156                 extra.add(f)
 157         needed = set()
 158         conn.write('list-indexes\n')
 159         for line in linereader(conn):
 160             if not line:
 161                 break
 162             assert(line.find('/') < 0)
 163             parts = line.split(' ')
 164             idx = parts[0]
 165             if len(parts) == 2 and parts[1] == 'load' and idx not in extra:
 166                 # If the server requests that we load an idx and we don't
 167                 # already have a copy of it, it is needed
 168                 needed.add(idx)
 169             # Any idx that the server has heard of is proven not extra
 170             extra.discard(idx)
 171
 172         self.check_ok()
 173         debug1('client: removing extra indexes: %s\n' % extra)
 174         for idx in extra:
 175             os.unlink(os.path.join(self.cachedir, idx))
 176         debug1('client: server requested load of: %s\n' % needed)
 177         for idx in needed:
 178             self.sync_index(idx)
 179         git.auto_midx(self.cachedir)
 180
 181     def sync_index(self, name):
 182         #debug1('requesting %r\n' % name)
 183         self.check_busy()
 184         mkdirp(self.cachedir)
 185         fn = os.path.join(self.cachedir, name)
 186         if os.path.exists(fn):
 187             msg = "won't request existing .idx, try `bup bloom --check %s`" % fn
 188             raise ClientError(msg)
 189         self.conn.write('send-index %s\n' % name)
 190         n = struct.unpack('!I', self.conn.read(4))[0]
 191         assert(n)
 192         with atomically_replaced_file(fn, 'w') as f:
 193             count = 0
 194             progress('Receiving index from server: %d/%d\r' % (count, n))
 195             for b in chunkyreader(self.conn, n):
 196                 f.write(b)
 197                 count += len(b)
 198                 qprogress('Receiving index from server: %d/%d\r' % (count, n))
 199             progress('Receiving index from server: %d/%d, done.\n' % (count, n))
 200             self.check_ok()
 201
 202     def _make_objcache(self):
 203         return git.PackIdxList(self.cachedir)
 204
 205     def _suggest_packs(self):
 206         ob = self._busy
 207         if ob:
 208             assert(ob == 'receive-objects-v2')
 209             self.conn.write('\xff\xff\xff\xff')  # suspend receive-objects-v2
 210         suggested = []
 211         for line in linereader(self.conn):
 212             if not line:
 213                 break
 214             debug2('%s\n' % line)
 215             if line.startswith('index '):
 216                 idx = line[6:]
 217                 debug1('client: received index suggestion: %s\n'
 218                        % git.shorten_hash(idx))
 219                 suggested.append(idx)
 220             else:
 221                 assert(line.endswith('.idx'))
 222                 debug1('client: completed writing pack, idx: %s\n'
 223                        % git.shorten_hash(line))
 224                 suggested.append(line)
 225         self.check_ok()
 226         if ob:
 227             self._busy = None
 228         idx = None
 229         for idx in suggested:
 230             self.sync_index(idx)
 231         git.auto_midx(self.cachedir)
 232         if ob:
 233             self._busy = ob
 234             self.conn.write('%s\n' % ob)
 235         return idx
 236
 237     def new_packwriter(self, compression_level = 1):
 238         self.check_busy()
 239         def _set_busy():
 240             self._busy = 'receive-objects-v2'
 241             self.conn.write('receive-objects-v2\n')
 242         return PackWriter_Remote(self.conn,
 243                                  objcache_maker = self._make_objcache,
 244                                  suggest_packs = self._suggest_packs,
 245                                  onopen = _set_busy,
 246                                  onclose = self._not_busy,
 247                                  ensure_busy = self.ensure_busy,
 248                                  compression_level = compression_level)
 249
 250     def read_ref(self, refname):
 251         self.check_busy()
 252         self.conn.write('read-ref %s\n' % refname)
 253         r = self.conn.readline().strip()
 254         self.check_ok()
 255         if r:
 256             assert(len(r) == 40)   # hexified sha
 257             return r.decode('hex')
 258         else:
 259             return None   # nonexistent ref
 260
 261     def update_ref(self, refname, newval, oldval):
 262         self.check_busy()
 263         self.conn.write('update-ref %s\n%s\n%s\n'
 264                         % (refname, newval.encode('hex'),
 265                            (oldval or '').encode('hex')))
 266         self.check_ok()
 267
 268     def cat(self, id):
 269         self.check_busy()
 270         self._busy = 'cat'
 271         self.conn.write('cat %s\n' % re.sub(r'[\n\r]', '_', id))
 272         while 1:
 273             sz = struct.unpack('!I', self.conn.read(4))[0]
 274             if not sz: break
 275             yield self.conn.read(sz)
 276         e = self.check_ok()
 277         self._not_busy()
 278         if e:
 279             raise KeyError(str(e))
 280
 281
 282 class PackWriter_Remote(git.PackWriter):
 283     def __init__(self, conn, objcache_maker, suggest_packs,
 284                  onopen, onclose,
 285                  ensure_busy,
 286                  compression_level=1):
 287         git.PackWriter.__init__(self, objcache_maker)
 288         self.file = conn
 289         self.filename = 'remote socket'
 290         self.suggest_packs = suggest_packs
 291         self.onopen = onopen
 292         self.onclose = onclose
 293         self.ensure_busy = ensure_busy
 294         self._packopen = False
 295         self._bwcount = 0
 296         self._bwtime = time.time()
 297
 298     def _open(self):
 299         if not self._packopen:
 300             self.onopen()
 301             self._packopen = True
 302
 303     def _end(self):
 304         if self._packopen and self.file:
 305             self.file.write('\0\0\0\0')
 306             self._packopen = False
 307             self.onclose() # Unbusy
 308             self.objcache = None
 309             return self.suggest_packs() # Returns last idx received
 310
 311     def close(self):
 312         id = self._end()
 313         self.file = None
 314         return id
 315
 316     def abort(self):
 317         raise ClientError("don't know how to abort remote pack writing")
 318
 319     def _raw_write(self, datalist, sha):
 320         assert(self.file)
 321         if not self._packopen:
 322             self._open()
 323         self.ensure_busy()
 324         data = ''.join(datalist)
 325         assert(data)
 326         assert(sha)
 327         crc = zlib.crc32(data) & 0xffffffff
 328         outbuf = ''.join((struct.pack('!I', len(data) + 20 + 4),
 329                           sha,
 330                           struct.pack('!I', crc),
 331                           data))
 332         try:
 333             (self._bwcount, self._bwtime) = _raw_write_bwlimit(
 334                     self.file, outbuf, self._bwcount, self._bwtime)
 335         except IOError as e:
 336             raise ClientError, e, sys.exc_info()[2]
 337         self.outbytes += len(data)
 338         self.count += 1
 339
 340         if self.file.has_input():
 341             self.suggest_packs()
 342             self.objcache.refresh()
 343
 344         return sha, crc