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