Mini Shell
'''
.. note:: New in verision 0.5.11
.. testsetup::
from pyroute2 import NDB
ndb = NDB(sources=[{'target': 'localhost', 'kind': 'IPMock'}])
.. testcleanup:: *
for key, value in tuple(globals().items()):
if key.startswith('ndb') and hasattr(value, 'close'):
value.close()
Filtering example:
.. testcode::
report = ndb.interfaces.dump()
report.select_fields('index', 'ifname', 'address', 'state')
report.transform_fields(
address=lambda r: '%s%s.%s%s.%s%s' % tuple(r.address.split(':'))
)
for record in report.format('csv'):
print(record)
.. testoutput::
'index','ifname','address','state'
1,'lo','0000.0000.0000','up'
2,'eth0','5254.0072.58b2','up'
'''
import json
import warnings
from itertools import chain
from pyroute2 import cli
MAX_REPORT_LINES = 10000
deprecation_notice = '''
RecordSet API is deprecated, pls refer to:
https://docs.pyroute2.org/ndb_reports.html
'''
def format_json(dump, headless=False):
buf = []
fnames = None
yield '['
for record in dump:
if fnames is None:
if headless:
fnames = record._names
else:
fnames = record
continue
if buf:
buf[-1] += ','
for line in buf:
yield line
buf = []
lines = json.dumps(dict(zip(fnames, record)), indent=4).split('\n')
buf.append(' {')
for line in sorted(lines[1:-1]):
if line[-1] == ',':
line = line[:-1]
buf.append(' %s,' % line)
buf[-1] = buf[-1][:-1]
buf.append(' }')
for line in buf:
yield line
yield ']'
def format_csv(dump, headless=False):
def dump_record(rec):
row = []
for field in rec:
if isinstance(field, int):
row.append('%i' % field)
elif field is None:
row.append('')
else:
row.append("'%s'" % field)
return row
fnames = None
for record in dump:
if fnames is None and headless:
fnames = True
yield ','.join(dump_record(record._names))
yield ','.join(dump_record(record))
class Record:
def __init__(self, names, values, ref_class=None):
self._names = tuple(names)
self._values = tuple(values)
if len(self._names) != len(self._values):
raise ValueError('names and values must have the same length')
self._ref_class = ref_class
def __getitem__(self, key):
idx = len(self._names)
for i in reversed(self._names):
idx -= 1
if i == key:
return self._values[idx]
def __setitem__(self, *argv, **kwarg):
raise TypeError('immutable object')
def __getattribute__(self, key):
if key.startswith('_'):
return object.__getattribute__(self, key)
else:
return self[key]
def __setattr__(self, key, value):
if not key.startswith('_'):
raise TypeError('immutable object')
return object.__setattr__(self, key, value)
def __iter__(self):
return iter(self._values)
def __repr__(self):
return repr(self._values)
def __len__(self):
return len(self._values)
def _select_fields(self, *fields):
return Record(fields, map(lambda x: self[x], fields), self._ref_class)
def _transform_fields(self, **spec):
data = self._as_dict()
for key, func in spec.items():
data[key] = func(self)
return Record(data.keys(), data.values(), self._ref_class)
def _match(self, f=None, **spec):
if callable(f):
return f(self)
for key, value in spec.items():
if not (
value(self[key]) if callable(value) else (self[key] == value)
):
return False
return True
def _as_dict(self):
ret = {}
for key, value in zip(self._names, self._values):
ret[key] = value
return ret
def __eq__(self, right):
if hasattr(right, '_names'):
n = all(x[0] == x[1] for x in zip(self._names, right._names))
v = all(x[0] == x[1] for x in zip(self._values, right._values))
return n and v
elif isinstance(right, dict):
for key, value in right.items():
if value != self[key]:
break
else:
return True
return False
elif self._ref_class is not None and isinstance(right, (str, int)):
return self._ref_class.compare_record(self, right)
else:
return all(x[0] == x[1] for x in zip(self._values, right))
class BaseRecordSet(object):
def __init__(self, generator, ellipsis='(...)'):
self.generator = generator
self.ellipsis = ellipsis
def __iter__(self):
return self
def __next__(self):
return next(self.generator)
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, traceback):
pass
def __repr__(self):
counter = 0
ret = []
for record in self:
if isinstance(record, str):
ret.append(record)
else:
ret.append(repr(record))
ret.append('\n')
counter += 1
if self.ellipsis and counter > MAX_REPORT_LINES:
ret.append(self.ellipsis)
break
if ret:
ret.pop()
return ''.join(ret)
class RecordSetConfig(dict):
def __init__(self, prime):
if isinstance(prime, dict):
for key, value in prime.items():
self[key] = value
else:
raise ValueError('only dict allowed')
def __setitem__(self, key, value):
if isinstance(value, str):
value = json.loads(value)
return super().__setitem__(key, value)
class RecordSet(BaseRecordSet):
'''
NDB views return objects of this class with `summary()` and `dump()`
methods. RecordSet objects are generator-based, they do not store the
data in the memory, but transform them on the fly.
RecordSet filters also return objects of this class, thus making possible
to make chains of filters.
'''
def __init__(self, generator, config=None, ellipsis=True):
super().__init__(generator, ellipsis)
self.filters = []
self.config = RecordSetConfig(config) if config is not None else {}
def __next__(self):
while True:
record = next(self.generator)
for f in self.filters:
record = f(record)
if record is None:
break
else:
return record
@cli.show_result
def select_fields(self, *fields):
'''
Select only chosen fields for every record:
.. testcode::
report = ndb.interfaces.dump()
report.select_fields('index', 'ifname')
for line in report.format('csv'):
print(line)
.. testoutput::
'index','ifname'
1,'lo'
2,'eth0'
'''
self.filters.append(lambda x: x._select_fields(*fields))
if self.config.get('recordset_pipe'):
return RecordSet(self, config=self.config)
@cli.show_result
def select_records(self, f=None, **spec):
'''
Select records based on a function f() or a spec match. A spec
is dictionary of pairs `field: constant` or `field: callable`:
.. testcode::
report = ndb.addresses.summary()
report.select_records(ifname=lambda x: x.startswith('eth'))
for line in report.format('csv'):
print(line)
.. testoutput::
'target','tflags','ifname','address','prefixlen'
'localhost',0,'eth0','192.168.122.28',24
'''
self.filters.append(lambda x: x if x._match(f, **spec) else None)
if self.config.get('recordset_pipe'):
return RecordSet(self, config=self.config)
@cli.show_result
def transform_fields(self, **kwarg):
'''
Transform fields with a function. Function must accept
the record as the only argument:
.. testcode::
report = ndb.addresses.summary()
report.transform_fields(
address=lambda r: f'{r.address}/{r.prefixlen}'
)
report.select_fields('ifname', 'address')
for line in report.format('csv'):
print(line)
.. testoutput::
'ifname','address'
'lo','127.0.0.1/8'
'eth0','192.168.122.28/24'
'''
self.filters.append(lambda x: x._transform_fields(**kwarg))
if self.config.get('recordset_pipe'):
return RecordSet(self, config=self.config)
@cli.show_result
def transform(self, **kwarg):
warnings.warn(deprecation_notice, DeprecationWarning)
def g():
for record in self.generator:
if isinstance(record, Record):
values = []
names = record._names
for name, value in zip(names, record._values):
if name in kwarg:
value = kwarg[name](value)
values.append(value)
record = Record(names, values, record._ref_class)
yield record
return RecordSet(g())
@cli.show_result
def filter(self, f=None, **kwarg):
warnings.warn(deprecation_notice, DeprecationWarning)
def g():
for record in self.generator:
m = True
for key in kwarg:
if kwarg[key] != getattr(record, key):
m = False
if m:
if f is None:
yield record
elif f(record):
yield record
return RecordSet(g())
@cli.show_result
def select(self, *argv):
warnings.warn(deprecation_notice, DeprecationWarning)
return self.fields(*argv)
@cli.show_result
def fields(self, *fields):
warnings.warn(deprecation_notice, DeprecationWarning)
def g():
for record in self.generator:
yield record._select_fields(*fields)
return RecordSet(g())
@cli.show_result
def join(self, right, condition=lambda r1, r2: True, prefix=''):
warnings.warn(deprecation_notice, DeprecationWarning)
# fetch all the records from the right
# ACHTUNG it may consume a lot of memory
right = tuple(right)
def g():
for r1 in self.generator:
for r2 in right:
if condition(r1, r2):
n = tuple(
chain(
r1._names,
['%s%s' % (prefix, x) for x in r2._names],
)
)
v = tuple(chain(r1._values, r2._values))
yield Record(n, v, r1._ref_class)
return RecordSet(g())
@cli.show_result
def format(self, kind):
'''
Return an iterator over text lines in the chosen format.
Supported formats: 'json', 'csv'.
'''
if kind == 'json':
return BaseRecordSet(format_json(self, headless=True))
elif kind == 'csv':
return BaseRecordSet(format_csv(self, headless=True))
else:
raise ValueError()
def count(self):
'''
Return number of records.
The method exhausts the generator.
'''
counter = 0
for record in self:
counter += 1
return counter
def __getitem__(self, key):
return list(self)[key]
Zerion Mini Shell 1.0