#
#
-# Copyright (C) 2010, 2011 Google Inc.
+# Copyright (C) 2010, 2011, 2012 Google Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
"""
+import re
+import string # pylint: disable=W0402
+import logging
+
+import pyparsing as pyp
+
from ganeti import errors
+from ganeti import utils
+from ganeti import compat
# Logic operators with one or more operands, each of which is a filter on its
# operator-specific value
OP_EQUAL = "="
OP_NOT_EQUAL = "!="
-OP_GLOB = "=*"
+OP_LT = "<"
+OP_LE = "<="
+OP_GT = ">"
+OP_GE = ">="
OP_REGEXP = "=~"
OP_CONTAINS = "=[]"
+#: Characters used for detecting user-written filters (see L{_CheckFilter})
+FILTER_DETECTION_CHARS = frozenset("()=/!~'\"\\<>" + string.whitespace)
+
+#: Characters used to detect globbing filters (see L{_CheckGlobbing})
+GLOB_DETECTION_CHARS = frozenset("*?")
+
+
def MakeSimpleFilter(namefield, values):
"""Builds simple a filter.
return [OP_OR] + [[OP_EQUAL, namefield, i] for i in values]
return None
+
+
+def _ConvertLogicOp(op):
+ """Creates parsing action function for logic operator.
+
+ @type op: string
+ @param op: Operator for data structure, e.g. L{OP_AND}
+
+ """
+ def fn(toks):
+ """Converts parser tokens to query operator structure.
+
+ @rtype: list
+ @return: Query operator structure, e.g. C{[OP_AND, ["=", "foo", "bar"]]}
+
+ """
+ operands = toks[0]
+
+ if len(operands) == 1:
+ return operands[0]
+
+ # Build query operator structure
+ return [[op] + operands.asList()]
+
+ return fn
+
+
+_KNOWN_REGEXP_DELIM = "/#^|"
+_KNOWN_REGEXP_FLAGS = frozenset("si")
+
+
+def _ConvertRegexpValue(_, loc, toks):
+ """Regular expression value for condition.
+
+ """
+ (regexp, flags) = toks[0]
+
+ # Ensure only whitelisted flags are used
+ unknown_flags = (frozenset(flags) - _KNOWN_REGEXP_FLAGS)
+ if unknown_flags:
+ raise pyp.ParseFatalException("Unknown regular expression flags: '%s'" %
+ "".join(unknown_flags), loc)
+
+ if flags:
+ re_flags = "(?%s)" % "".join(sorted(flags))
+ else:
+ re_flags = ""
+
+ re_cond = re_flags + regexp
+
+ # Test if valid
+ try:
+ re.compile(re_cond)
+ except re.error, err:
+ raise pyp.ParseFatalException("Invalid regular expression (%s)" % err, loc)
+
+ return [re_cond]
+
+
+def BuildFilterParser():
+ """Builds a parser for query filter strings.
+
+ @rtype: pyparsing.ParserElement
+
+ """
+ field_name = pyp.Word(pyp.alphas, pyp.alphanums + "_/.")
+
+ # Integer
+ num_sign = pyp.Word("-+", exact=1)
+ number = pyp.Combine(pyp.Optional(num_sign) + pyp.Word(pyp.nums))
+ number.setParseAction(lambda toks: int(toks[0]))
+
+ quoted_string = pyp.quotedString.copy().setParseAction(pyp.removeQuotes)
+
+ # Right-hand-side value
+ rval = (number | quoted_string)
+
+ # Boolean condition
+ bool_cond = field_name.copy()
+ bool_cond.setParseAction(lambda (fname, ): [[OP_TRUE, fname]])
+
+ # Simple binary conditions
+ binopstbl = {
+ "==": OP_EQUAL,
+ "!=": OP_NOT_EQUAL,
+ "<": OP_LT,
+ "<=": OP_LE,
+ ">": OP_GT,
+ ">=": OP_GE,
+ }
+
+ binary_cond = (field_name + pyp.oneOf(binopstbl.keys()) + rval)
+ binary_cond.setParseAction(lambda (lhs, op, rhs): [[binopstbl[op], lhs, rhs]])
+
+ # "in" condition
+ in_cond = (rval + pyp.Suppress("in") + field_name)
+ in_cond.setParseAction(lambda (value, field): [[OP_CONTAINS, field, value]])
+
+ # "not in" condition
+ not_in_cond = (rval + pyp.Suppress("not") + pyp.Suppress("in") + field_name)
+ not_in_cond.setParseAction(lambda (value, field): [[OP_NOT, [OP_CONTAINS,
+ field, value]]])
+
+ # Regular expression, e.g. m/foobar/i
+ regexp_val = pyp.Group(pyp.Optional("m").suppress() +
+ pyp.MatchFirst([pyp.QuotedString(i, escChar="\\")
+ for i in _KNOWN_REGEXP_DELIM]) +
+ pyp.Optional(pyp.Word(pyp.alphas), default=""))
+ regexp_val.setParseAction(_ConvertRegexpValue)
+ regexp_cond = (field_name + pyp.Suppress("=~") + regexp_val)
+ regexp_cond.setParseAction(lambda (field, value): [[OP_REGEXP, field, value]])
+
+ not_regexp_cond = (field_name + pyp.Suppress("!~") + regexp_val)
+ not_regexp_cond.setParseAction(lambda (field, value):
+ [[OP_NOT, [OP_REGEXP, field, value]]])
+
+ # Globbing, e.g. name =* "*.site"
+ glob_cond = (field_name + pyp.Suppress("=*") + quoted_string)
+ glob_cond.setParseAction(lambda (field, value):
+ [[OP_REGEXP, field,
+ utils.DnsNameGlobPattern(value)]])
+
+ not_glob_cond = (field_name + pyp.Suppress("!*") + quoted_string)
+ not_glob_cond.setParseAction(lambda (field, value):
+ [[OP_NOT, [OP_REGEXP, field,
+ utils.DnsNameGlobPattern(value)]]])
+
+ # All possible conditions
+ condition = (binary_cond ^ bool_cond ^
+ in_cond ^ not_in_cond ^
+ regexp_cond ^ not_regexp_cond ^
+ glob_cond ^ not_glob_cond)
+
+ # Associativity operators
+ filter_expr = pyp.operatorPrecedence(condition, [
+ (pyp.Keyword("not").suppress(), 1, pyp.opAssoc.RIGHT,
+ lambda toks: [[OP_NOT, toks[0][0]]]),
+ (pyp.Keyword("and").suppress(), 2, pyp.opAssoc.LEFT,
+ _ConvertLogicOp(OP_AND)),
+ (pyp.Keyword("or").suppress(), 2, pyp.opAssoc.LEFT,
+ _ConvertLogicOp(OP_OR)),
+ ])
+
+ parser = pyp.StringStart() + filter_expr + pyp.StringEnd()
+ parser.parseWithTabs()
+
+ # Originally C{parser.validate} was called here, but there seems to be some
+ # issue causing it to fail whenever the "not" operator is included above.
+
+ return parser
+
+
+def ParseFilter(text, parser=None):
+ """Parses a query filter.
+
+ @type text: string
+ @param text: Query filter
+ @type parser: pyparsing.ParserElement
+ @param parser: Pyparsing object
+ @rtype: list
+
+ """
+ logging.debug("Parsing as query filter: %s", text)
+
+ if parser is None:
+ parser = BuildFilterParser()
+
+ try:
+ return parser.parseString(text)[0]
+ except pyp.ParseBaseException, err:
+ raise errors.QueryFilterParseError("Failed to parse query filter"
+ " '%s': %s" % (text, err), err)
+
+
+def _CheckFilter(text):
+ """CHecks if a string could be a filter.
+
+ @rtype: bool
+
+ """
+ return bool(frozenset(text) & FILTER_DETECTION_CHARS)
+
+
+def _CheckGlobbing(text):
+ """Checks if a string could be a globbing pattern.
+
+ @rtype: bool
+
+ """
+ return bool(frozenset(text) & GLOB_DETECTION_CHARS)
+
+
+def _MakeFilterPart(namefield, text, isnumeric=False):
+ """Generates filter for one argument.
+
+ """
+ if isnumeric:
+ try:
+ number = int(text)
+ except (TypeError, ValueError), err:
+ raise errors.OpPrereqError("Invalid job ID passed: %s" % str(err),
+ errors.ECODE_INVAL)
+ return [OP_EQUAL, namefield, number]
+ elif _CheckGlobbing(text):
+ return [OP_REGEXP, namefield, utils.DnsNameGlobPattern(text)]
+ else:
+ return [OP_EQUAL, namefield, text]
+
+
+def MakeFilter(args, force_filter, namefield=None, isnumeric=False):
+ """Try to make a filter from arguments to a command.
+
+ If the name could be a filter it is parsed as such. If it's just a globbing
+ pattern, e.g. "*.site", such a filter is constructed. As a last resort the
+ names are treated just as a plain name filter.
+
+ @type args: list of string
+ @param args: Arguments to command
+ @type force_filter: bool
+ @param force_filter: Whether to force treatment as a full-fledged filter
+ @type namefield: string
+ @param namefield: Name of field to use for simple filters (use L{None} for
+ a default of "name")
+ @type isnumeric: bool
+ @param isnumeric: Whether the namefield type is numeric, as opposed to
+ the default string type; this influences how the filter is built
+ @rtype: list
+ @return: Query filter
+
+ """
+ if namefield is None:
+ namefield = "name"
+
+ if (force_filter or
+ (args and len(args) == 1 and _CheckFilter(args[0]))):
+ try:
+ (filter_text, ) = args
+ except (TypeError, ValueError):
+ raise errors.OpPrereqError("Exactly one argument must be given as a"
+ " filter", errors.ECODE_INVAL)
+
+ result = ParseFilter(filter_text)
+ elif args:
+ result = [OP_OR] + map(compat.partial(_MakeFilterPart, namefield,
+ isnumeric=isnumeric), args)
+ else:
+ result = None
+
+ return result
projects / ganeti-local / blobdiff