Base classes for matcher and library

libs/caper/matcher.py

@@ -0,0 +1,144 @@
+# Copyright 2013 Dean Gardiner <gardiner91@gmail.com>
+#
+# 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.
+
+from caper.helpers import is_list_type, update_dict, delta_seconds
+from datetime import datetime
+from logr import Logr
+import re
+
+
+class FragmentMatcher(object):
+    def __init__(self, pattern_groups):
+        self.regex = {}
+
+        self.construct_patterns(pattern_groups)
+
+    def construct_patterns(self, pattern_groups):
+        compile_start = datetime.now()
+        compile_count = 0
+
+        for group_name, patterns in pattern_groups:
+            if group_name not in self.regex:
+                self.regex[group_name] = []
+
+            # Transform into weight groups
+            if type(patterns[0]) is str or type(patterns[0][0]) not in [int, float]:
+                patterns = [(1.0, patterns)]
+
+            for weight, patterns in patterns:
+                weight_patterns = []
+
+                for pattern in patterns:
+                    # Transform into multi-fragment patterns
+                    if type(pattern) is str:
+                        pattern = (pattern,)
+
+                    if type(pattern) is tuple and len(pattern) == 2:
+                        if type(pattern[0]) is str and is_list_type(pattern[1], str):
+                            pattern = (pattern,)
+
+                    result = []
+                    for value in pattern:
+                        if type(value) is tuple:
+                            if len(value) == 2:
+                                # Construct OR-list pattern
+                                value = value[0] % '|'.join(value[1])
+                            elif len(value) == 1:
+                                value = value[0]
+
+                        result.append(re.compile(value, re.IGNORECASE))
+                        compile_count += 1
+
+                    weight_patterns.append(tuple(result))
+
+                self.regex[group_name].append((weight, weight_patterns))
+
+        Logr.info("Compiled %s patterns in %ss", compile_count, delta_seconds(datetime.now() - compile_start))
+
+    def find_group(self, name):
+        for group_name, weight_groups in self.regex.items():
+            if group_name and group_name == name:
+                return group_name, weight_groups
+
+        return None, None
+
+    def value_match(self, value, group_name=None, single=True):
+        result = None
+
+        for group, weight_groups in self.regex.items():
+            if group_name and group != group_name:
+                continue
+
+            # TODO handle multiple weights
+            weight, patterns = weight_groups[0]
+
+            for pattern in patterns:
+                match = pattern[0].match(value)
+                if not match:
+                    continue
+
+                if result is None:
+                    result = {}
+                if group not in result:
+                    result[group] = {}
+
+                result[group].update(match.groupdict())
+
+                if single:
+                    return result
+
+        return result
+
+    def fragment_match(self, fragment, group_name=None):
+        """Follow a fragment chain to try find a match
+
+        :type fragment: caper.objects.CaperFragment
+        :type group_name: str or None
+
+        :return: The weight of the match found between 0.0 and 1.0,
+                  where 1.0 means perfect match and 0.0 means no match
+        :rtype: (float, dict, int)
+        """
+
+        group_name, weight_groups = self.find_group(group_name)
+
+        for weight, patterns in weight_groups:
+            for pattern in patterns:
+                cur_fragment = fragment
+                success = True
+                result = {}
+
+                # Ignore empty patterns
+                if len(pattern) < 1:
+                    break
+
+                for fragment_pattern in pattern:
+                    if not cur_fragment:
+                        success = False
+                        break
+
+                    match = fragment_pattern.match(cur_fragment.value)
+                    if match:
+                        update_dict(result, match.groupdict())
+                    else:
+                        success = False
+                        break
+
+                    cur_fragment = cur_fragment.right if cur_fragment else None
+
+                if success:
+                    Logr.debug("Found match with weight %s" % weight)
+                    return float(weight), result, len(pattern)
+
+        return 0.0, None, 1