borg/attic/remote.py

223 lines
8.0 KiB
Python

import fcntl
import msgpack
import os
import select
from subprocess import Popen, PIPE
import sys
from .helpers import Error, IntegrityError
from .repository import Repository
BUFSIZE = 10 * 1024 * 1024
class ConnectionClosed(Error):
"""Connection closed by remote host"""
class RepositoryServer(object):
def __init__(self):
self.repository = None
def serve(self):
# Make stdin non-blocking
fl = fcntl.fcntl(sys.stdin.fileno(), fcntl.F_GETFL)
fcntl.fcntl(sys.stdin.fileno(), fcntl.F_SETFL, fl | os.O_NONBLOCK)
# Make stdout blocking
fl = fcntl.fcntl(sys.stdout.fileno(), fcntl.F_GETFL)
fcntl.fcntl(sys.stdout.fileno(), fcntl.F_SETFL, fl & ~os.O_NONBLOCK)
unpacker = msgpack.Unpacker(use_list=False)
while True:
r, w, es = select.select([sys.stdin], [], [], 10)
if r:
data = os.read(sys.stdin.fileno(), BUFSIZE)
if not data:
return
unpacker.feed(data)
for type, msgid, method, args in unpacker:
method = method.decode('ascii')
try:
try:
f = getattr(self, method)
except AttributeError:
f = getattr(self.repository, method)
res = f(*args)
except Exception as e:
sys.stdout.buffer.write(msgpack.packb((1, msgid, e.__class__.__name__, e.args)))
else:
sys.stdout.buffer.write(msgpack.packb((1, msgid, None, res)))
sys.stdout.flush()
if es:
return
def negotiate(self, versions):
return 1
def open(self, path, create=False):
path = os.fsdecode(path)
if path.startswith('/~'):
path = path[1:]
self.repository = Repository(os.path.expanduser(path), create)
return self.repository.id
class RemoteRepository(object):
class RPCError(Exception):
def __init__(self, name):
self.name = name
def __init__(self, location, create=False):
self.location = location
self.preload_ids = []
self.msgid = 0
self.to_send = b''
self.cache = {}
self.ignore_responses = set()
self.responses = {}
self.unpacker = msgpack.Unpacker(use_list=False)
self.p = None
if location.host == '__testsuite__':
args = [sys.executable, '-m', 'attic.archiver', 'serve']
else:
args = ['ssh']
if location.port:
args += ['-p', str(location.port)]
if location.user:
args.append('%s@%s' % (location.user, location.host))
else:
args.append('%s' % location.host)
args += ['attic', 'serve']
self.p = Popen(args, bufsize=0, stdin=PIPE, stdout=PIPE)
self.stdin_fd = self.p.stdin.fileno()
self.stdout_fd = self.p.stdout.fileno()
fcntl.fcntl(self.stdin_fd, fcntl.F_SETFL, fcntl.fcntl(self.stdin_fd, fcntl.F_GETFL) | os.O_NONBLOCK)
fcntl.fcntl(self.stdout_fd, fcntl.F_SETFL, fcntl.fcntl(self.stdout_fd, fcntl.F_GETFL) | os.O_NONBLOCK)
self.r_fds = [self.stdout_fd]
self.x_fds = [self.stdin_fd, self.stdout_fd]
version = self.call('negotiate', 1)
if version != 1:
raise Exception('Server insisted on using unsupported protocol version %d' % version)
self.id = self.call('open', location.path, create)
def __del__(self):
self.close()
def call(self, cmd, *args, **kw):
for resp in self.call_many(cmd, [args], **kw):
return resp
def call_many(self, cmd, calls, wait=True, is_preloaded=False):
if not calls:
return
def fetch_from_cache(args):
msgid = self.cache[args].pop(0)
if not self.cache[args]:
del self.cache[args]
return msgid
calls = list(calls)
waiting_for = []
w_fds = [self.stdin_fd]
while wait or calls:
while waiting_for:
try:
error, res = self.responses.pop(waiting_for[0])
waiting_for.pop(0)
if error:
if error == b'DoesNotExist':
raise Repository.DoesNotExist(self.location.orig)
elif error == b'AlreadyExists':
raise Repository.AlreadyExists(self.location.orig)
elif error == b'CheckNeeded':
raise Repository.CheckNeeded(self.location.orig)
elif error == b'IntegrityError':
raise IntegrityError(res)
raise self.RPCError(error)
else:
yield res
if not waiting_for and not calls:
return
except KeyError:
break
r, w, x = select.select(self.r_fds, w_fds, self.x_fds, 1)
if x:
raise Exception('FD exception occured')
if r:
data = os.read(self.stdout_fd, BUFSIZE)
if not data:
raise ConnectionClosed()
self.unpacker.feed(data)
for type, msgid, error, res in self.unpacker:
if msgid in self.ignore_responses:
self.ignore_responses.remove(msgid)
else:
self.responses[msgid] = error, res
if w:
while not self.to_send and (calls or self.preload_ids) and len(waiting_for) < 100:
if calls:
if is_preloaded:
if calls[0] in self.cache:
waiting_for.append(fetch_from_cache(calls.pop(0)))
else:
args = calls.pop(0)
if cmd == 'get' and args in self.cache:
waiting_for.append(fetch_from_cache(args))
else:
self.msgid += 1
waiting_for.append(self.msgid)
self.to_send = msgpack.packb((1, self.msgid, cmd, args))
if not self.to_send and self.preload_ids:
args = (self.preload_ids.pop(0),)
self.msgid += 1
self.cache.setdefault(args, []).append(self.msgid)
self.to_send = msgpack.packb((1, self.msgid, cmd, args))
if self.to_send:
self.to_send = self.to_send[os.write(self.stdin_fd, self.to_send):]
if not self.to_send and not (calls or self.preload_ids):
w_fds = []
self.ignore_responses |= set(waiting_for)
def check(self, progress=False, repair=False):
return self.call('check', progress, repair)
def commit(self, *args):
return self.call('commit')
def rollback(self, *args):
return self.call('rollback')
def __len__(self):
return self.call('__len__')
def list(self, limit=None, marker=None):
return self.call('list', limit, marker)
def get(self, id_):
for resp in self.get_many([id_]):
return resp
def get_many(self, ids, is_preloaded=False):
for resp in self.call_many('get', [(id_,) for id_ in ids], is_preloaded=is_preloaded):
yield resp
def put(self, id_, data, wait=True):
return self.call('put', id_, data, wait=wait)
def delete(self, id_, wait=True):
return self.call('delete', id_, wait=wait)
def close(self):
if self.p:
self.p.stdin.close()
self.p.stdout.close()
self.p.wait()
self.p = None
def preload(self, ids):
self.preload_ids += ids