Merge pull request #3331 from jreback/index_perf

PERF: fixed int64 indexing perf issue when conversion to int64

Author: jreback

pandas/core/index.py

@@ -1332,11 +1332,6 @@ def inferred_type(self):
     def _constructor(self):
         return Int64Index
 
-    @cache_readonly
-    def _engine(self):
-        # property, for now, slow to look up
-        return self._engine_type(lambda: com._ensure_int64(self.values), len(self))
-
     @property
     def asi8(self):
         # do not cache or you'll create a memory leak

pandas/index.pyx

@@ -272,6 +272,9 @@ cdef class IndexEngine:
 
 cdef class Int64Engine(IndexEngine):
 
+    cdef _get_index_values(self):
+        return algos.ensure_int64(self.vgetter())
+
     cdef _make_hash_table(self, n):
         return _hash.Int64HashTable(n)