deb-murano/murano/dsl/macros.py
Stan Lagun 9a9f3436e1 Version-aware YAML loading
* Refactoring of "packages" Python package
* Now MuranoPL YAML classes can be parsed by different engines
depending on Format string in package manifest

With this change MuranoPL classes will no longer
be read and parsed (including YAQL expressions parsing)
upon package load but only on first class access and
with ability to peak different parsers depending on
format version specified in manifest. As a consequence
it is now possible to use different YAQL engines for
different package format versions. Also startup
time was greatly improved as unneeded classes are no more
parsed and logos and UI forms are not loaded.

Partially implements: blueprint murano-versioning

Change-Id: I23fc5da1a43b405d526438329dc04aed589dee13
2015-09-03 12:07:13 +00:00

260 lines
8.8 KiB
Python

# Copyright (c) 2014 Mirantis, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import types
from murano.dsl import constants
from murano.dsl import dsl_exception
from murano.dsl import exceptions
from murano.dsl import expressions
from murano.dsl import helpers
from murano.dsl import yaql_expression
class CodeBlock(expressions.DslExpression):
def __init__(self, body):
if not isinstance(body, types.ListType):
body = [body]
self.code_block = map(expressions.parse_expression, body)
def execute(self, context):
for expr in self.code_block:
if hasattr(expr, 'virtual_instruction'):
instruction = expr.virtual_instruction
context[constants.CTX_CURRENT_INSTRUCTION] = instruction
try:
expr.execute(context)
except (dsl_exception.MuranoPlException,
exceptions.InternalFlowException):
raise
except Exception as ex:
raise dsl_exception.MuranoPlException.from_python_exception(
ex, context)
class MethodBlock(CodeBlock):
def __init__(self, body, name=None):
super(MethodBlock, self).__init__(body)
self._name = name
def execute(self, context):
new_context = context.create_child_context()
try:
super(MethodBlock, self).execute(new_context)
except exceptions.ReturnException as e:
return e.value
except exceptions.BreakException:
raise exceptions.DslInvalidOperationError(
'Break cannot be used on method level')
except exceptions.ContinueException:
raise exceptions.DslInvalidOperationError(
'Continue cannot be used on method level')
else:
return None
class ReturnMacro(expressions.DslExpression):
def __init__(self, Return):
self._value = Return
def execute(self, context):
raise exceptions.ReturnException(
helpers.evaluate(self._value, context))
class BreakMacro(expressions.DslExpression):
def __init__(self, Break):
if Break:
raise exceptions.DslSyntaxError('Break cannot have value')
def execute(self, context):
raise exceptions.BreakException()
class ContinueMacro(expressions.DslExpression):
def __init__(self, Continue):
if Continue:
raise exceptions.DslSyntaxError('Continue cannot have value')
def execute(self, context):
raise exceptions.ContinueException()
class ParallelMacro(CodeBlock):
def __init__(self, Parallel, Limit=None):
super(ParallelMacro, self).__init__(Parallel)
self._limit = Limit or len(self.code_block)
def execute(self, context):
if not self.code_block:
return
limit = helpers.evaluate(self._limit, context)
helpers.parallel_select(
self.code_block, lambda expr: expr.execute(context), limit)
class IfMacro(expressions.DslExpression):
def __init__(self, If, Then, Else=None):
if not isinstance(If, yaql_expression.YaqlExpression):
raise exceptions.DslSyntaxError(
'Condition must be of expression type')
self._code1 = CodeBlock(Then)
self._code2 = None if Else is None else CodeBlock(Else)
self._condition = If
def execute(self, context):
res = self._condition(context)
if not isinstance(res, types.BooleanType):
raise exceptions.DslInvalidOperationError(
'Condition must be evaluated to boolean type')
if res:
self._code1.execute(context)
elif self._code2 is not None:
self._code2.execute(context)
class WhileDoMacro(expressions.DslExpression):
def __init__(self, While, Do):
if not isinstance(While, yaql_expression.YaqlExpression):
raise TypeError()
self._code = CodeBlock(Do)
self._condition = While
def execute(self, context):
while True:
res = self._condition(context)
if not isinstance(res, types.BooleanType):
raise exceptions.DslSyntaxError(
'Condition must be of expression type')
try:
if res:
self._code.execute(context)
else:
break
except exceptions.BreakException:
break
except exceptions.ContinueException:
continue
class ForMacro(expressions.DslExpression):
def __init__(self, For, In, Do):
if not isinstance(For, types.StringTypes):
raise exceptions.DslSyntaxError(
'For value must be of string type')
self._code = CodeBlock(Do)
self._var = For
self._collection = In
def execute(self, context):
collection = helpers.evaluate(self._collection, context)
for t in collection:
context[self._var] = t
try:
self._code.execute(context)
except exceptions.BreakException:
break
except exceptions.ContinueException:
continue
class RepeatMacro(expressions.DslExpression):
def __init__(self, Repeat, Do):
if not isinstance(Repeat, (int, yaql_expression.YaqlExpression)):
raise exceptions.DslSyntaxError(
'Repeat value must be either int or expression')
self._count = Repeat
self._code = CodeBlock(Do)
def execute(self, context):
count = helpers.evaluate(self._count, context)
for t in range(0, count):
try:
self._code.execute(context)
except exceptions.BreakException:
break
except exceptions.ContinueException:
continue
class MatchMacro(expressions.DslExpression):
def __init__(self, Match, Value, Default=None):
if not isinstance(Match, types.DictionaryType):
raise exceptions.DslSyntaxError(
'Match value must be of dictionary type')
self._switch = Match
self._value = Value
self._default = None if Default is None else CodeBlock(Default)
def execute(self, context):
match_value = helpers.evaluate(self._value, context)
for key, value in self._switch.iteritems():
if key == match_value:
CodeBlock(value).execute(context)
return
if self._default is not None:
self._default.execute(context)
class SwitchMacro(expressions.DslExpression):
def __init__(self, Switch, Default=None):
if not isinstance(Switch, types.DictionaryType):
raise exceptions.DslSyntaxError(
'Switch value must be of dictionary type')
self._switch = Switch
for key, value in self._switch.iteritems():
if not isinstance(key, (yaql_expression.YaqlExpression,
types.BooleanType)):
raise exceptions.DslSyntaxError(
'Switch cases must be must be either '
'boolean or expression')
self._default = None if Default is None else CodeBlock(Default)
def execute(self, context):
matched = False
for key, value in self._switch.iteritems():
res = helpers.evaluate(key, context)
if not isinstance(res, types.BooleanType):
raise exceptions.DslInvalidOperationError(
'Switch case must be evaluated to boolean type')
if res:
matched = True
CodeBlock(value).execute(context)
if self._default is not None and not matched:
self._default.execute(context)
class DoMacro(expressions.DslExpression):
def __init__(self, Do):
self._code = CodeBlock(Do)
def execute(self, context):
self._code.execute(context)
def register():
expressions.register_macro(DoMacro)
expressions.register_macro(ReturnMacro)
expressions.register_macro(BreakMacro)
expressions.register_macro(ContinueMacro)
expressions.register_macro(ParallelMacro)
expressions.register_macro(IfMacro)
expressions.register_macro(WhileDoMacro)
expressions.register_macro(ForMacro)
expressions.register_macro(RepeatMacro)
expressions.register_macro(MatchMacro)
expressions.register_macro(SwitchMacro)