127 lines
4.2 KiB
Python
127 lines
4.2 KiB
Python
# Copyright 2013 - Mirantis, Inc.
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# Copyright 2015 - StackStorm, Inc.
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# Copyright 2016 - Brocade Communications Systems, Inc.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import inspect
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import re
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from oslo_log import log as logging
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import six
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from yaql.language import exceptions as yaql_exc
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from yaql.language import factory
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from mistral import exceptions as exc
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from mistral.expressions.base_expression import Evaluator
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from mistral.utils import expression_utils
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LOG = logging.getLogger(__name__)
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YAQL_ENGINE = factory.YaqlFactory().create()
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INLINE_YAQL_REGEXP = '<%.*?%>'
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class YAQLEvaluator(Evaluator):
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@classmethod
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def validate(cls, expression):
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LOG.debug("Validating YAQL expression [expression='%s']", expression)
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try:
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YAQL_ENGINE(expression)
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except (yaql_exc.YaqlException, KeyError, ValueError, TypeError) as e:
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raise exc.YaqlGrammarException(getattr(e, 'message', e))
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@classmethod
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def evaluate(cls, expression, data_context):
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expression = expression.strip() if expression else expression
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LOG.debug(
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"Evaluating YAQL expression [expression='%s', context=%s]"
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% (expression, data_context)
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)
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try:
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result = YAQL_ENGINE(expression).evaluate(
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context=expression_utils.get_yaql_context(data_context)
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)
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except Exception as e:
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raise exc.YaqlEvaluationException(
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"Can not evaluate YAQL expression [expression=%s, error=%s"
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", data=%s]" % (expression, str(e), data_context)
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)
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LOG.debug("YAQL expression result: %s" % result)
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return result if not inspect.isgenerator(result) else list(result)
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@classmethod
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def is_expression(cls, s):
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# The class should not be used outside of InlineYAQLEvaluator since by
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# convention, YAQL expression should always be wrapped in '<% %>'.
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return False
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class InlineYAQLEvaluator(YAQLEvaluator):
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# This regular expression will look for multiple occurrences of YAQL
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# expressions in '<% %>' (i.e. <% any_symbols %>) within a string.
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find_expression_pattern = re.compile(INLINE_YAQL_REGEXP)
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@classmethod
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def validate(cls, expression):
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LOG.debug(
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"Validating inline YAQL expression [expression='%s']", expression)
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if not isinstance(expression, six.string_types):
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raise exc.YaqlEvaluationException(
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"Unsupported type '%s'." % type(expression)
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)
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found_expressions = cls.find_inline_expressions(expression)
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if found_expressions:
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[super(InlineYAQLEvaluator, cls).validate(expr.strip("<%>"))
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for expr in found_expressions]
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@classmethod
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def evaluate(cls, expression, data_context):
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LOG.debug(
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"Evaluating inline YAQL expression [expression='%s', context=%s]"
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% (expression, data_context)
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)
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result = expression
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found_expressions = cls.find_inline_expressions(expression)
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if found_expressions:
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for expr in found_expressions:
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trim_expr = expr.strip("<%>")
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evaluated = super(InlineYAQLEvaluator,
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cls).evaluate(trim_expr, data_context)
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if len(expression) == len(expr):
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result = evaluated
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else:
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result = result.replace(expr, str(evaluated))
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LOG.debug("Inline YAQL expression result: %s" % result)
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return result
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@classmethod
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def is_expression(cls, s):
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return cls.find_expression_pattern.search(s)
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@classmethod
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def find_inline_expressions(cls, s):
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return cls.find_expression_pattern.findall(s)
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