"""
+import re
+import string # pylint: disable-msg=W0402
+
+import pyparsing as pyp
+
+from ganeti import errors
+from ganeti import netutils
+
+
# Logic operators with one or more operands, each of which is a filter on its
# own
OP_OR = "|"
OP_CONTAINS = "=[]"
+#: Characters used for detecting user-written filters (see L{MaybeFilter})
+FILTER_DETECTION_CHARS = frozenset("()=/!~" + string.whitespace)
+
+
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]))
+
+ # Right-hand-side value
+ rval = (number | pyp.quotedString.setParseAction(pyp.removeQuotes))
+
+ # Boolean condition
+ bool_cond = field_name.copy()
+ bool_cond.setParseAction(lambda (fname, ): [[OP_TRUE, fname]])
+
+ # Simple binary conditions
+ binopstbl = {
+ "==": OP_EQUAL,
+ "!=": OP_NOT_EQUAL,
+ }
+
+ 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]]])
+
+ # All possible conditions
+ condition = (binary_cond ^ bool_cond ^
+ in_cond ^ not_in_cond ^
+ regexp_cond ^ not_regexp_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
+
+ """
+ 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 MaybeFilter(text):
+ """Try to determine if a string is a filter or a name.
+
+ If in doubt, this function treats a text as a name.
+
+ @type text: string
+ @param text: String to be examined
+ @rtype: bool
+
+ """
+ # Quick check for punctuation and whitespace
+ if frozenset(text) & FILTER_DETECTION_CHARS:
+ return True
+
+ try:
+ netutils.Hostname.GetNormalizedName(text)
+ except errors.OpPrereqError:
+ # Not a valid hostname, treat as filter
+ return True
+
+ # Most probably a name
+ return False
projects / ganeti-local / blobdiff