lib/bup/client.py

   1 import re, struct, errno, select
   2 from bup import git
   3 from bup.helpers import *
   4 from subprocess import Popen, PIPE
   5
   6
   7 class ClientError(Exception):
   8     pass
   9
  10
  11 class Client:
  12     def __init__(self, remote, create=False):
  13         self._busy = None
  14         self.p = None
  15         self.conn = None
  16         rs = remote.split(':', 1)
  17         main_exe = os.environ.get('BUP_MAIN_EXE') or sys.argv[0]
  18         nicedir = os.path.split(os.path.abspath(main_exe))[0]
  19         nicedir = re.sub(r':', "_", nicedir)
  20         if len(rs) == 1:
  21             (host, dir) = ('NONE', remote)
  22             def fixenv():
  23                 os.environ['PATH'] = ':'.join([nicedir,
  24                                                os.environ.get('PATH', '')])
  25             argv = ['bup', 'server']
  26         else:
  27             (host, dir) = rs
  28             fixenv = None
  29             # WARNING: shell quoting security holes are possible here, so we
  30             # have to be super careful.  We have to use 'sh -c' because
  31             # csh-derived shells can't handle PATH= notation.  We can't
  32             # set PATH in advance, because ssh probably replaces it.  We
  33             # can't exec *safely* using argv, because *both* ssh and 'sh -c'
  34             # allow shellquoting.  So we end up having to double-shellquote
  35             # stuff here.
  36             escapedir = re.sub(r'([^\w/])', r'\\\\\\\1', nicedir)
  37             cmd = r"""
  38                        sh -c PATH=%s:'$PATH bup server'
  39                    """ % escapedir
  40             argv = ['ssh', host, '--', cmd.strip()]
  41             #log('argv is: %r\n' % argv)
  42         def setup():
  43             if fixenv:
  44                 fixenv()
  45             os.setsid()
  46         (self.host, self.dir) = (host, dir)
  47         self.cachedir = git.repo('index-cache/%s'
  48                                  % re.sub(r'[^@\w]', '_',
  49                                           "%s:%s" % (host, dir)))
  50         try:
  51             self.p = p = Popen(argv, stdin=PIPE, stdout=PIPE, preexec_fn=setup)
  52         except OSError, e:
  53             raise ClientError, 'exec %r: %s' % (argv[0], e), sys.exc_info()[2]
  54         self.conn = conn = Conn(p.stdout, p.stdin)
  55         if dir:
  56             dir = re.sub(r'[\r\n]', ' ', dir)
  57             if create:
  58                 conn.write('init-dir %s\n' % dir)
  59             else:
  60                 conn.write('set-dir %s\n' % dir)
  61             self.check_ok()
  62         self.sync_indexes_del()
  63
  64     def __del__(self):
  65         try:
  66             self.close()
  67         except IOError, e:
  68             if e.errno == errno.EPIPE:
  69                 pass
  70             else:
  71                 raise
  72
  73     def close(self):
  74         if self.conn and not self._busy:
  75             self.conn.write('quit\n')
  76         if self.p:
  77             self.p.stdin.close()
  78             while self.p.stdout.read(65536):
  79                 pass
  80             self.p.stdout.close()
  81             self.p.wait()
  82             rv = self.p.wait()
  83             if rv:
  84                 raise ClientError('server tunnel returned exit code %d' % rv)
  85         self.conn = None
  86         self.p = None
  87
  88     def check_ok(self):
  89         rv = self.p.poll()
  90         if rv != None:
  91             raise ClientError('server exited unexpectedly with code %r' % rv)
  92         try:
  93             return self.conn.check_ok()
  94         except Exception, e:
  95             raise ClientError, e, sys.exc_info()[2]
  96
  97     def check_busy(self):
  98         if self._busy:
  99             raise ClientError('already busy with command %r' % self._busy)
 100
 101     def _not_busy(self):
 102         self._busy = None
 103
 104     def sync_indexes_del(self):
 105         self.check_busy()
 106         conn = self.conn
 107         conn.write('list-indexes\n')
 108         packdir = git.repo('objects/pack')
 109         all = {}
 110         needed = {}
 111         for line in linereader(conn):
 112             if not line:
 113                 break
 114             all[line] = 1
 115             assert(line.find('/') < 0)
 116             if not os.path.exists(os.path.join(self.cachedir, line)):
 117                 needed[line] = 1
 118         self.check_ok()
 119
 120         mkdirp(self.cachedir)
 121         for f in os.listdir(self.cachedir):
 122             if f.endswith('.idx') and not f in all:
 123                 log('pruning old index: %r\n' % f)
 124                 os.unlink(os.path.join(self.cachedir, f))
 125
 126     def sync_index(self, name):
 127         #log('requesting %r\n' % name)
 128         mkdirp(self.cachedir)
 129         self.conn.write('send-index %s\n' % name)
 130         n = struct.unpack('!I', self.conn.read(4))[0]
 131         assert(n)
 132         fn = os.path.join(self.cachedir, name)
 133         f = open(fn + '.tmp', 'w')
 134         count = 0
 135         progress('Receiving index: %d/%d\r' % (count, n))
 136         for b in chunkyreader(self.conn, n):
 137             f.write(b)
 138             count += len(b)
 139             progress('Receiving index: %d/%d\r' % (count, n))
 140         progress('Receiving index: %d/%d, done.\n' % (count, n))
 141         self.check_ok()
 142         f.close()
 143         os.rename(fn + '.tmp', fn)
 144
 145     def _make_objcache(self):
 146         ob = self._busy
 147         self._busy = None
 148         #self.sync_indexes()
 149         self._busy = ob
 150         return git.PackIdxList(self.cachedir)
 151
 152     def _suggest_pack(self, indexname):
 153         log('received index suggestion: %s\n' % indexname)
 154         ob = self._busy
 155         if ob:
 156             assert(ob == 'receive-objects')
 157             self._busy = None
 158             self.conn.write('\xff\xff\xff\xff')  # suspend receive-objects
 159             self.conn.drain_and_check_ok()
 160         self.sync_index(indexname)
 161         if ob:
 162             self.conn.write('receive-objects\n')
 163             self._busy = ob
 164
 165     def new_packwriter(self):
 166         self.check_busy()
 167         self._busy = 'receive-objects'
 168         return PackWriter_Remote(self.conn,
 169                                  objcache_maker = self._make_objcache,
 170                                  suggest_pack = self._suggest_pack,
 171                                  onclose = self._not_busy)
 172
 173     def read_ref(self, refname):
 174         self.check_busy()
 175         self.conn.write('read-ref %s\n' % refname)
 176         r = self.conn.readline().strip()
 177         self.check_ok()
 178         if r:
 179             assert(len(r) == 40)   # hexified sha
 180             return r.decode('hex')
 181         else:
 182             return None   # nonexistent ref
 183
 184     def update_ref(self, refname, newval, oldval):
 185         self.check_busy()
 186         self.conn.write('update-ref %s\n%s\n%s\n'
 187                         % (refname, newval.encode('hex'),
 188                            (oldval or '').encode('hex')))
 189         self.check_ok()
 190
 191     def cat(self, id):
 192         self.check_busy()
 193         self._busy = 'cat'
 194         self.conn.write('cat %s\n' % re.sub(r'[\n\r]', '_', id))
 195         while 1:
 196             sz = struct.unpack('!I', self.conn.read(4))[0]
 197             if not sz: break
 198             yield self.conn.read(sz)
 199         e = self.check_ok()
 200         self._not_busy()
 201         if e:
 202             raise KeyError(str(e))
 203
 204
 205 class PackWriter_Remote(git.PackWriter):
 206     def __init__(self, conn, objcache_maker, suggest_pack, onclose):
 207         git.PackWriter.__init__(self, objcache_maker)
 208         self.file = conn
 209         self.filename = 'remote socket'
 210         self.suggest_pack = suggest_pack
 211         self.onclose = onclose
 212         self._packopen = False
 213
 214     def _open(self):
 215         if not self._packopen:
 216             self._make_objcache()
 217             self.file.write('receive-objects\n')
 218             self._packopen = True
 219
 220     def _end(self):
 221         if self._packopen and self.file:
 222             self.file.write('\0\0\0\0')
 223             self._packopen = False
 224             while True:
 225                 line = self.file.readline().strip()
 226                 if line.startswith('index '):
 227                     pass
 228                 else:
 229                     break
 230             id = line
 231             self.file.check_ok()
 232             self.objcache = None
 233             if self.onclose:
 234                 self.onclose()
 235             if self.suggest_pack:
 236                 self.suggest_pack(id)
 237             return id
 238
 239     def close(self):
 240         id = self._end()
 241         self.file = None
 242         return id
 243
 244     def abort(self):
 245         raise GitError("don't know how to abort remote pack writing")
 246
 247     def _raw_write(self, datalist):
 248         assert(self.file)
 249         if not self._packopen:
 250             self._open()
 251         data = ''.join(datalist)
 252         assert(len(data))
 253         self.file.write(struct.pack('!I', len(data)) + data)
 254         self.outbytes += len(data)
 255         self.count += 1
 256
 257         if self.file.has_input():
 258             line = self.file.readline().strip()
 259             assert(line.startswith('index '))
 260             idxname = line[6:]
 261             if self.suggest_pack:
 262                 self.suggest_pack(idxname)
 263                 self.objcache.refresh()