Add handling for metadata footers

Author: jeffreylovitz

Diff for: redisgraph/graph.py

@@ -58,6 +58,12 @@ def _refresh_attributes(self):
         for i, p in enumerate(props):
             self._properties[i] = p[0]
 
+    def refresh_metadata(self, version, labels, reltypes, properties):
+        self.version = version
+        self._labels = labels
+        self._relationshipTypes = reltypes
+        self._properties = properties
+
     def get_label(self, idx):
         try:
             label = self._labels[idx]

Diff for: redisgraph/query_result.py

@@ -57,8 +57,10 @@ def __init__(self, graph, response):
             self.parse_statistics(response[0])
         else:
             # start by parsing statistics, matches the one we have
-            self.parse_statistics(response[-1])  # Last element.
+            self.parse_statistics(response[2])  # Third element, after header and records.
             self.parse_results(response)
+            if len(response) == 4:
+                self.parse_metadata(response[3])
 
     def _check_for_errors(self, response):
         if isinstance(response[0], ResponseError):
@@ -94,6 +96,36 @@ def parse_statistics(self, raw_statistics):
             if v is not None:
                 self.statistics[s] = v
 
+    def parse_metadata(self, raw_metadata):
+        # Decode metadata:
+        # [
+        #   ["version", VERSION],
+        #   ["labels", [[VALUE_STRING, "label_1"] ... ]],
+        #   ["relationship types ", [[VALUE_STRING, "reltype_1"] ... ]],
+        #   ["property keys", [[VALUE_STRING, "prop_1"] ... ]]
+        # ]
+        version = raw_metadata[0][1]
+        raw_labels = raw_metadata[1][1]
+        raw_reltypes = raw_metadata[2][1]
+        raw_props = raw_metadata[3][1]
+
+        # Arrays to be passed into the internal graph structure.
+        labels = [None] * len(raw_labels)
+        reltypes = [None] * len(raw_reltypes)
+        properties = [None] * len(raw_props)
+
+        for idx, label in enumerate(raw_labels):
+            labels[idx] = self.parse_scalar(label)
+
+        for idx, reltype in enumerate(raw_reltypes):
+            reltypes[idx] = self.parse_scalar(reltype)
+
+        for idx, prop in enumerate(raw_props):
+            properties[idx] = self.parse_scalar(prop)
+
+        # Update the graph's internal metadata.
+        self.graph.refresh_metadata(version, labels, reltypes, properties)
+
     def parse_header(self, raw_result_set):
         # An array of column name/column type pairs.
         header = raw_result_set[0]

Diff for: tests/functional/test_all.py

@@ -328,6 +328,18 @@ def test_cache_sync(self):
         assert(A._relationshipTypes[0] == 'S')
         assert(A._relationshipTypes[1] == 'R')
 
+    def test_metadata(self):
+        A = Graph('metadata', self.r)
+        # Since this query modifies schemas and returns data, it should
+        # update all graph metadata in a single call.
+        A.query("CREATE (l:L {v: 1}) RETURN l")
+        assert(len(A._labels) == 1)
+        assert(len(A._properties) == 1)
+        assert(len(A._relationshipTypes) == 0)
+        assert(A._labels[0] == 'L')
+        assert(A._properties[0] == 'v')
+        assert(A.version != 0)
+
 
 if __name__ == '__main__':
     unittest.main()