/usr/lib/python2.7/dist-packages/landscape/schema.py is in landscape-common 14.01-0ubuntu3.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 | """A schema system. Yes. Another one!"""
class InvalidError(Exception):
"""Raised when invalid input is received."""
pass
class Constant(object):
"""Something that must be equal to a constant value."""
def __init__(self, value):
self.value = value
def coerce(self, value):
if value != self.value:
raise InvalidError("%r != %r" % (value, self.value))
return value
class Any(object):
"""Something which must apply to any of a number of different schemas.
@param schemas: Other schema objects.
"""
def __init__(self, *schemas):
self.schemas = schemas
def coerce(self, value):
"""
The result of the first schema which doesn't raise
L{InvalidError} from its C{coerce} method will be returned.
"""
for schema in self.schemas:
try:
return schema.coerce(value)
except InvalidError:
pass
raise InvalidError("%r did not match any schema in %s"
% (value, self.schemas))
class Bool(object):
"""Something that must be a C{bool}."""
def coerce(self, value):
if not isinstance(value, bool):
raise InvalidError("%r is not a bool" % (value,))
return value
class Int(object):
"""Something that must be an C{int} or C{long}."""
def coerce(self, value):
if not isinstance(value, (int, long)):
raise InvalidError("%r isn't an int or long" % (value,))
return value
class Float(object):
"""Something that must be an C{int}, C{long}, or C{float}."""
def coerce(self, value):
if not isinstance(value, (int, long, float)):
raise InvalidError("%r isn't a float" % (value,))
return value
class Bytes(object):
"""A binary string."""
def coerce(self, value):
if not isinstance(value, str):
raise InvalidError("%r isn't a str" % (value,))
return value
class Unicode(object):
"""Something that must be a C{unicode}.
If the value is a C{str}, it will automatically be decoded.
@param encoding: The encoding to automatically decode C{str}s with.
"""
def __init__(self, encoding="utf-8"):
self.encoding = encoding
def coerce(self, value):
if isinstance(value, str):
try:
value = value.decode(self.encoding)
except UnicodeDecodeError, e:
raise InvalidError("%r can't be decoded: %s" % (value, str(e)))
if not isinstance(value, unicode):
raise InvalidError("%r isn't a unicode" % (value,))
return value
class List(object):
"""Something which must be a C{list}.
@param schema: The schema that all values of the list must match.
"""
def __init__(self, schema):
self.schema = schema
def coerce(self, value):
if not isinstance(value, list):
raise InvalidError("%r is not a list" % (value,))
new_list = list(value)
for i, subvalue in enumerate(value):
try:
new_list[i] = self.schema.coerce(subvalue)
except InvalidError, e:
raise InvalidError(
"%r could not coerce with %s: %s"
% (subvalue, self.schema, e))
return new_list
class Tuple(object):
"""Something which must be a fixed-length tuple.
@param schema: A sequence of schemas, which will be applied to
each value in the tuple respectively.
"""
def __init__(self, *schema):
self.schema = schema
def coerce(self, value):
if not isinstance(value, tuple):
raise InvalidError("%r is not a tuple" % (value,))
if len(value) != len(self.schema):
raise InvalidError("Need %s items, got %s in %r"
% (len(self.schema), len(value), value))
new_value = []
for schema, value in zip(self.schema, value):
new_value.append(schema.coerce(value))
return tuple(new_value)
class KeyDict(object):
"""Something which must be a C{dict} with defined keys.
The keys must be constant and the values must match a per-key schema.
@param schema: A dict mapping keys to schemas that the values of those
keys must match.
"""
def __init__(self, schema, optional=None):
if optional is None:
optional = []
self.optional = set(optional)
self.schema = schema
def coerce(self, value):
new_dict = {}
if not isinstance(value, dict):
raise InvalidError("%r is not a dict." % (value,))
for k, v in value.iteritems():
if k not in self.schema:
raise InvalidError("%r is not a valid key as per %r"
% (k, self.schema))
try:
new_dict[k] = self.schema[k].coerce(v)
except InvalidError, e:
raise InvalidError(
"Value of %r key of dict %r could not coerce with %s: %s"
% (k, value, self.schema[k], e))
new_keys = set(new_dict.keys())
required_keys = set(self.schema.keys()) - self.optional
missing = required_keys - new_keys
if missing:
raise InvalidError("Missing keys %s" % (missing,))
return new_dict
class Dict(object):
"""Something which must be a C{dict} with arbitrary keys.
@param key_schema: The schema that keys must match.
@param value_schema: The schema that values must match.
"""
def __init__(self, key_schema, value_schema):
self.key_schema = key_schema
self.value_schema = value_schema
def coerce(self, value):
if not isinstance(value, dict):
raise InvalidError("%r is not a dict." % (value,))
new_dict = {}
for k, v in value.items():
new_dict[self.key_schema.coerce(k)] = self.value_schema.coerce(v)
return new_dict
class Message(KeyDict):
"""
Like L{KeyDict}, but with three predefined keys: C{type}, C{api},
and C{timestamp}. Of these, C{api} and C{timestamp} are optional.
@param type: The type of the message. The C{type} key will need to
match this as a constant.
@param schema: A dict of additional schema in a format L{KeyDict}
will accept.
@param optional: An optional list of keys that should be optional.
"""
def __init__(self, type, schema, optional=None):
self.type = type
schema["timestamp"] = Float()
schema["api"] = Any(Bytes(), Constant(None))
schema["type"] = Constant(type)
if optional is not None:
optional.extend(["timestamp", "api"])
else:
optional = ["timestamp", "api"]
super(Message, self).__init__(schema, optional=optional)
def coerce(self, value):
for k in value.keys():
if k not in self.schema:
# We don't know about this field, just discard it. This
# is useful when a client that introduced some new field
# in a message talks to an older server, that don't understand
# the new field yet.
value.pop(k)
return super(Message, self).coerce(value)
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