def save_snapshot(tega_id):
'''
Take a snapshot of _idb and saves it to the hard disk.
'''
global _log_fd
_idb_snapshot = {}
for root_oid in _idb:
_idb_snapshot[root_oid] = _idb[root_oid].serialize_(
internal=True, serialize_ephemeral=False)
num = commit_log_number(server_tega_id, _log_dir)
filename = _commit_log_filename(server_tega_id, num + 1)
log_file = os.path.join(_log_dir, filename)
if _log_fd:
_log_fd.close()
_log_fd = open(log_file, 'a+') # append-only file
finish_marker = COMMIT_FINISH_MARKER + '{}'.format(now())
_log_fd.write(COMMIT_START_MARKER + '\n') # commit start
for root_oid, instance in _idb_snapshot.items():
log = log_entry(ope=OPE.SS.name,
path=root_oid,
tega_id=tega_id,
instance=instance)
log = str(log)
_log_fd.write(log + '\n')
_log_fd.write(finish_marker + '\n') # commit finish marker
_log_fd.flush()
os.fsync(_log_fd)
def save_snapshot(tega_id):
'''
Take a snapshot of _idb and saves it to the hard disk.
'''
global _log_fd
_idb_snapshot = {}
for root_oid in _idb:
_idb_snapshot[root_oid] = _idb[root_oid].serialize_(internal=True,
serialize_ephemeral=False)
num = commit_log_number(server_tega_id, _log_dir)
filename = _commit_log_filename(server_tega_id, num+1)
log_file = os.path.join(_log_dir, filename)
if _log_fd:
_log_fd.close()
_log_fd = open(log_file, 'a+') # append-only file
finish_marker = COMMIT_FINISH_MARKER+'{}'.format(now())
_log_fd.write(COMMIT_START_MARKER+'\n') # commit start
for root_oid, instance in _idb_snapshot.items():
log = log_entry(ope=OPE.SS.name, path=root_oid, tega_id=tega_id, instance=instance)
log = str(log)
_log_fd.write(log+'\n')
_log_fd.write(finish_marker+'\n') # commit finish marker
_log_fd.flush()
os.fsync(_log_fd)
def start(data_dir, tega_id, maxlen=OLD_ROOTS_LEN):
'''
Starts tega db
'''
global _log_fd
global _log_dir
global server_tega_id
server_tega_id = tega_id
_log_dir = os.path.join(os.path.expanduser(data_dir))
num = commit_log_number(server_tega_id, _log_dir)
filename = _commit_log_filename(server_tega_id, num)
log_file = os.path.join(_log_dir, filename)
try:
_log_fd = open(log_file, 'a+') # append-only file
except FileNotFoundError:
raise
old_roots_len = maxlen
def start(data_dir, tega_id, maxlen=OLD_ROOTS_LEN):
'''
Starts tega db
'''
global _log_fd
global _log_dir
global server_tega_id
server_tega_id = tega_id
_log_dir = os.path.join(os.path.expanduser(data_dir))
num = commit_log_number(server_tega_id, _log_dir)
filename = _commit_log_filename(server_tega_id, num)
log_file = os.path.join(_log_dir, filename)
try:
_log_fd = open(log_file, 'a+') # append-only file
except FileNotFoundError:
raise
old_roots_len = maxlen
def clear():
'''
Empties tega-db file and in-memory DB
'''
global _log_fd, _log_dir, _idb, _old_roots, server_tega_id
# Clears idb
_idb = {}
_old_roots = {}
# Removes commit log files
_log_fd.close()
max_ = commit_log_number(server_tega_id, _log_dir)
for i in range(0, max_ + 1):
log_file = os.path.join(_log_dir, _commit_log_filename(server_tega_id, i))
if os.path.exists(log_file):
os.remove(log_file)
# Reopens an empty commit log file
log_file = os.path.join(_log_dir, _commit_log_filename(server_tega_id, 0))
_log_fd = open(log_file, 'a+') # append-onlyfile
def clear():
'''
Empties tega-db file and in-memory DB
'''
global _log_fd, _log_dir, _idb, _old_roots, server_tega_id
# Clears idb
_idb = {}
_old_roots = {}
# Removes commit log files
_log_fd.close()
max_ = commit_log_number(server_tega_id, _log_dir)
for i in range(0, max_ + 1):
log_file = os.path.join(_log_dir,
_commit_log_filename(server_tega_id, i))
if os.path.exists(log_file):
os.remove(log_file)
# Reopens an empty commit log file
log_file = os.path.join(_log_dir, _commit_log_filename(server_tega_id, 0))
_log_fd = open(log_file, 'a+') # append-onlyfile
def loglist_for_sync(root_oid, version):
'''
Accumulates log entries until the version.
log.global.0 log.global.l log.global.n
+------------+ +------------+ +------------+ ^
| | | SS | | SS | |
| | |------------| | | |
| | | | ^ | | |
| | | | | | | |
+------------+ +------------+ | +------------+ |
'''
multi = []
notifications = []
if version < 0:
version = -1
try:
version_ = _idb[root_oid]['_version']
except KeyError:
return multi
if version_ <= version:
return multi
max_ = commit_log_number(server_tega_id, _log_dir)
continue_ = True
begin = False
match = False
while continue_ and max_ >= 0:
filename = _commit_log_filename(server_tega_id, max_)
log_file = os.path.join(_log_dir, filename)
max_ -= 1
with open(log_file, 'r') as fd:
g = readline_reverse(fd)
while True:
try:
line = next(g).rstrip('\n')
except StopIteration:
break
if line == '':
pass
elif line.startswith(COMMIT_FINISH_MARKER):
begin = True
elif line.startswith(COMMIT_START_MARKER):
begin = False
if match:
version_ -= 1
match = False
multi.insert(0, notifications)
notifications = []
if version_ <= version:
continue_ = False
break
elif line.startswith(ROLLBACK_MARKER):
args = line.split(' ')
root_oid_ = args[2]
if root_oid_ == root_oid:
backto = args[0]
tega_id = args[1]
log = log_entry(ope=OPE.ROLLBACK.name,
path=root_oid,
tega_id=tega_id,
instance=None,
backto=int(backto))
if notifications:
multi.insert(0, notifications)
notifications = [log]
multi.insert(0, notifications)
notifications = []
version_ -= 1
if version_ <= version:
continue_ = False
break
elif begin:
log = eval(line)
ope = log['ope']
path = log['path']
tega_id = log['tega_id']
instance = log['instance']
if ope == OPE.SS.name:
pass
elif path.split('.')[0] == root_oid:
match = True
log = log_entry(ope=ope,
path=path,
tega_id=tega_id,
instance=instance)
notifications.insert(0, log)
return multi
def loglist_for_sync(root_oid, version):
'''
Accumulates log entries until the version.
log.global.0 log.global.l log.global.n
+------------+ +------------+ +------------+ ^
| | | SS | | SS | |
| | |------------| | | |
| | | | ^ | | |
| | | | | | | |
+------------+ +------------+ | +------------+ |
'''
multi = []
notifications = []
if version < 0:
version = -1
try:
version_ = _idb[root_oid]['_version']
except KeyError:
return multi
if version_ <= version:
return multi
max_ = commit_log_number(server_tega_id, _log_dir)
continue_ = True
begin = False
match = False
while continue_ and max_ >= 0:
filename = _commit_log_filename(server_tega_id, max_)
log_file = os.path.join(_log_dir, filename)
max_ -= 1
with open(log_file, 'r') as fd:
g = readline_reverse(fd)
while True:
try:
line = next(g).rstrip('\n')
except StopIteration:
break
if line == '':
pass
elif line.startswith(COMMIT_FINISH_MARKER):
begin = True
elif line.startswith(COMMIT_START_MARKER):
begin = False
if match:
version_ -= 1
match = False
multi.insert(0, notifications)
notifications = []
if version_ <= version:
continue_ = False
break
elif line.startswith(ROLLBACK_MARKER):
args = line.split(' ')
root_oid_ = args[2]
if root_oid_ == root_oid:
backto = args[0]
tega_id = args[1]
log = log_entry(ope=OPE.ROLLBACK.name, path=root_oid,
tega_id=tega_id, instance=None,
backto=int(backto))
if notifications:
multi.insert(0, notifications)
notifications = [log]
multi.insert(0, notifications)
notifications = []
version_ -= 1
if version_ <= version:
continue_ = False
break
elif begin:
log = eval(line)
ope = log['ope']
path = log['path']
tega_id = log['tega_id']
instance = log['instance']
if ope == OPE.SS.name:
pass
elif path.split('.')[0] == root_oid:
match = True
log = log_entry(ope=ope, path=path, tega_id=tega_id,
instance=instance)
notifications.insert(0, log)
return multi
