Merge branch 'master' of https://code.grnet.gr/git/pithos into id

[pithos] / pithos / lib / filter.py

diff --git a/pithos/lib/filter.py b/pithos/lib/filter.py
new file mode 100644 (file)
index 0000000..6b9e1e3
--- /dev/null
+++ b/pithos/lib/filter.py
@@ -0,0 +1,64 @@
+# Copyright 2011 GRNET S.A. All rights reserved.
+# 
+# Redistribution and use in source and binary forms, with or
+# without modification, are permitted provided that the following
+# conditions are met:
+# 
+#   1. Redistributions of source code must retain the above
+#      copyright notice, this list of conditions and the following
+#      disclaimer.
+# 
+#   2. Redistributions in binary form must reproduce the above
+#      copyright notice, this list of conditions and the following
+#      disclaimer in the documentation and/or other materials
+#      provided with the distribution.
+# 
+# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
+# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+# 
+# The views and conclusions contained in the software and
+# documentation are those of the authors and should not be
+# interpreted as representing official policies, either expressed
+# or implied, of GRNET S.A.
+
+import re
+import operator
+
+_regexfilter = re.compile('(!?)\s*(\S+?)\s*(?:(=|!=|<=|>=|<|>)\s*(\S*?)\s*)?$', re.UNICODE)
+
+OPERATORS = {'=':operator.eq,
+             '!=':operator.ne,
+             '<=':operator.le,
+             '>=':operator.ge,
+             '<':operator.lt,
+             '>':operator.gt
+}
+
+def parse_filters(terms):
+    included = []
+    excluded = []
+    opers = []
+    match = _regexfilter.match
+    for term in terms:
+        m = match(term)
+        if m is None:
+            continue
+        neg, key, op, value = m.groups()
+        if neg:
+            excluded.append(key)
+        elif op:
+            opers.append((key, op, value))
+        elif not value:
+            included.append(key)
+    
+    return included, excluded, opers