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         assert(url_match.group(1) in ('ssh', 'bup', 'file'))
  44         return url_match.group(1,3,4,5)
  45     else:
  46         rs = remote.split(':', 1)
  47         if len(rs) == 1 or rs[0] in ('', '-'):
  48             return 'file', None, None, rs[-1]
  49         else:
  50             return 'ssh', rs[0], None, rs[1]
  51
  52
  53 class Client:
  54     def __init__(self, remote, create=False):
  55         self._busy = self.conn = None
  56         self.sock = self.p = self.pout = self.pin = None
  57         is_reverse = os.environ.get('BUP_SERVER_REVERSE')
  58         if is_reverse:
  59             assert(not remote)
  60             remote = '%s:' % is_reverse
  61         (self.protocol, self.host, self.port, self.dir) = parse_remote(remote)
  62         self.cachedir = git.repo('index-cache/%s'
  63                                  % re.sub(r'[^@\w]', '_',
  64                                           "%s:%s" % (self.host, self.dir)))
  65         if is_reverse:
  66             self.pout = os.fdopen(3, 'rb')
  67             self.pin = os.fdopen(4, 'wb')
  68             self.conn = Conn(self.pout, self.pin)
  69         else:
  70             if self.protocol in ('ssh', 'file'):
  71                 try:
  72                     # FIXME: ssh and file shouldn't use the same module
  73                     self.p = ssh.connect(self.host, self.port, 'server')
  74                     self.pout = self.p.stdout
  75                     self.pin = self.p.stdin
  76                     self.conn = Conn(self.pout, self.pin)
  77                 except OSError, e:
  78                     raise ClientError, 'connect: %s' % e, sys.exc_info()[2]
  79             elif self.protocol == 'bup':
  80                 self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  81                 self.sock.connect((self.host, atoi(self.port) or 1982))
  82                 self.sockw = self.sock.makefile('wb')
  83                 self.conn = DemuxConn(self.sock.fileno(), self.sockw)
  84         if self.dir:
  85             self.dir = re.sub(r'[\r\n]', ' ', self.dir)
  86             if create:
  87                 self.conn.write('init-dir %s\n' % self.dir)
  88             else:
  89                 self.conn.write('set-dir %s\n' % self.dir)
  90             self.check_ok()
  91         self.sync_indexes()
  92
  93     def __del__(self):
  94         try:
  95             self.close()
  96         except IOError, e:
  97             if e.errno == errno.EPIPE:
  98                 pass
  99             else:
 100                 raise
 101
 102     def close(self):
 103         if self.conn and not self._busy:
 104             self.conn.write('quit\n')
 105         if self.pin:
 106             self.pin.close()
 107         if self.sock and self.sockw:
 108             self.sockw.close()
 109             self.sock.shutdown(socket.SHUT_WR)
 110         if self.conn:
 111             self.conn.close()
 112         if self.pout:
 113             self.pout.close()
 114         if self.sock:
 115             self.sock.close()
 116         if self.p:
 117             self.p.wait()
 118             rv = self.p.wait()
 119             if rv:
 120                 raise ClientError('server tunnel returned exit code %d' % rv)
 121         self.conn = None
 122         self.sock = self.p = self.pin = self.pout = None
 123
 124     def check_ok(self):
 125         if self.p:
 126             rv = self.p.poll()
 127             if rv != None:
 128                 raise ClientError('server exited unexpectedly with code %r'
 129                                   % rv)
 130         try:
 131             return self.conn.check_ok()
 132         except Exception, e:
 133             raise ClientError, e, sys.exc_info()[2]
 134
 135     def check_busy(self):
 136         if self._busy:
 137             raise ClientError('already busy with command %r' % self._busy)
 138
 139     def ensure_busy(self):
 140         if not self._busy:
 141             raise ClientError('expected to be busy, but not busy?!')
 142
 143     def _not_busy(self):
 144         self._busy = None
 145
 146     def sync_indexes(self):
 147         self.check_busy()
 148         conn = self.conn
 149         mkdirp(self.cachedir)
 150         # All cached idxs are extra until proven otherwise
 151         extra = set()
 152         for f in os.listdir(self.cachedir):
 153             debug1('%s\n' % f)
 154             if f.endswith('.idx'):
 155                 extra.add(f)
 156         needed = set()
 157         conn.write('list-indexes\n')
 158         for line in linereader(conn):
 159             if not line:
 160                 break
 161             assert(line.find('/') < 0)
 162             parts = line.split(' ')
 163             idx = parts[0]
 164             if len(parts) == 2 and parts[1] == 'load' and idx not in extra:
 165                 # If the server requests that we load an idx and we don't
 166                 # already have a copy of it, it is needed
 167                 needed.add(idx)
 168             # Any idx that the server has heard of is proven not extra
 169             extra.discard(idx)
 170
 171         self.check_ok()
 172         debug1('client: removing extra indexes: %s\n' % extra)
 173         for idx in extra:
 174             os.unlink(os.path.join(self.cachedir, idx))
 175         debug1('client: server requested load of: %s\n' % needed)
 176         for idx in needed:
 177             self.sync_index(idx)
 178         git.auto_midx(self.cachedir)
 179
 180     def sync_index(self, name):
 181         #debug1('requesting %r\n' % name)
 182         self.check_busy()
 183         mkdirp(self.cachedir)
 184         fn = os.path.join(self.cachedir, name)
 185         if os.path.exists(fn):
 186             msg = "won't request existing .idx, try `bup bloom --check %s`" % fn
 187             raise ClientError(msg)
 188         self.conn.write('send-index %s\n' % name)
 189         n = struct.unpack('!I', self.conn.read(4))[0]
 190         assert(n)
 191         f = open(fn + '.tmp', 'w')
 192         count = 0
 193         progress('Receiving index from server: %d/%d\r' % (count, n))
 194         for b in chunkyreader(self.conn, n):
 195             f.write(b)
 196             count += len(b)
 197             qprogress('Receiving index from server: %d/%d\r' % (count, n))
 198         progress('Receiving index from server: %d/%d, done.\n' % (count, n))
 199         self.check_ok()
 200         f.close()
 201         os.rename(fn + '.tmp', fn)
 202
 203     def _make_objcache(self):
 204         return git.PackIdxList(self.cachedir)
 205
 206     def _suggest_packs(self):
 207         ob = self._busy
 208         if ob:
 209             assert(ob == 'receive-objects-v2')
 210             self.conn.write('\xff\xff\xff\xff')  # suspend receive-objects-v2
 211         suggested = []
 212         for line in linereader(self.conn):
 213             if not line:
 214                 break
 215             debug2('%s\n' % line)
 216             if line.startswith('index '):
 217                 idx = line[6:]
 218                 debug1('client: received index suggestion: %s\n'
 219                        % git.shorten_hash(idx))
 220                 suggested.append(idx)
 221             else:
 222                 assert(line.endswith('.idx'))
 223                 debug1('client: completed writing pack, idx: %s\n'
 224                        % git.shorten_hash(line))
 225                 suggested.append(line)
 226         self.check_ok()
 227         if ob:
 228             self._busy = None
 229         idx = None
 230         for idx in suggested:
 231             self.sync_index(idx)
 232         git.auto_midx(self.cachedir)
 233         if ob:
 234             self._busy = ob
 235             self.conn.write('%s\n' % ob)
 236         return idx
 237
 238     def new_packwriter(self):
 239         self.check_busy()
 240         def _set_busy():
 241             self._busy = 'receive-objects-v2'
 242             self.conn.write('receive-objects-v2\n')
 243         return PackWriter_Remote(self.conn,
 244                                  objcache_maker = self._make_objcache,
 245                                  suggest_packs = self._suggest_packs,
 246                                  onopen = _set_busy,
 247                                  onclose = self._not_busy,
 248                                  ensure_busy = self.ensure_busy)
 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         git.PackWriter.__init__(self, objcache_maker)
 287         self.file = conn
 288         self.filename = 'remote socket'
 289         self.suggest_packs = suggest_packs
 290         self.onopen = onopen
 291         self.onclose = onclose
 292         self.ensure_busy = ensure_busy
 293         self._packopen = False
 294         self._bwcount = 0
 295         self._bwtime = time.time()
 296
 297     def _open(self):
 298         if not self._packopen:
 299             self.onopen()
 300             self._packopen = True
 301
 302     def _end(self):
 303         if self._packopen and self.file:
 304             self.file.write('\0\0\0\0')
 305             self._packopen = False
 306             self.onclose() # Unbusy
 307             self.objcache = None
 308             return self.suggest_packs() # Returns last idx received
 309
 310     def close(self):
 311         id = self._end()
 312         self.file = None
 313         return id
 314
 315     def abort(self):
 316         raise ClientError("don't know how to abort remote pack writing")
 317
 318     def _raw_write(self, datalist, sha):
 319         assert(self.file)
 320         if not self._packopen:
 321             self._open()
 322         self.ensure_busy()
 323         data = ''.join(datalist)
 324         assert(data)
 325         assert(sha)
 326         crc = zlib.crc32(data) & 0xffffffff
 327         outbuf = ''.join((struct.pack('!I', len(data) + 20 + 4),
 328                           sha,
 329                           struct.pack('!I', crc),
 330                           data))
 331         try:
 332             (self._bwcount, self._bwtime) = _raw_write_bwlimit(
 333                     self.file, outbuf, self._bwcount, self._bwtime)
 334         except IOError, e:
 335             raise ClientError, e, sys.exc_info()[2]
 336         self.outbytes += len(data)
 337         self.count += 1
 338
 339         if self.file.has_input():
 340             self.suggest_packs()
 341             self.objcache.refresh()
 342
 343         return sha, crc