introducing IntpHashMap

Author: realead

pandas/_libs/hashtable.pyx

@@ -65,6 +65,24 @@ cdef Py_ssize_t _INIT_VEC_CAP = 128
 include "hashtable_class_helper.pxi"
 include "hashtable_func_helper.pxi"
 
+
+# map derived hash-map types onto basic hash-map types:
+if np.dtype(np.intp) == np.dtype(np.int64):
+    IntpHashTable = Int64HashTable
+    value_count_intp = value_count_int64
+    duplicated_intp = duplicated_int64
+    ismember_intp = ismember_int64
+    mode_intp = mode_int64
+elif np.dtype(np.intp) == np.dtype(np.int32):
+    IntpHashTable = Int32HashTable
+    value_count_intp = value_count_int32
+    duplicated_intp = duplicated_int32
+    ismember_intp = ismember_int32
+    mode_intp = mode_int32
+else:
+    raise ValueError(np.dtype(np.intp))
+
+
 cdef class Factorizer:
     cdef readonly:
         Py_ssize_t count

pandas/tests/libs/test_hashtable.py

@@ -44,6 +44,7 @@ def get_allocated_khash_memory():
         (ht.UInt16HashTable, np.uint16),
         (ht.Int8HashTable, np.int8),
         (ht.UInt8HashTable, np.uint8),
+        (ht.IntpHashTable, np.intp),
     ],
 )
 class TestHashTable:
@@ -389,6 +390,7 @@ def get_ht_function(fun_name, type_suffix):
         (np.uint16, "uint16"),
         (np.int8, "int8"),
         (np.uint8, "uint8"),
+        (np.intp, "intp"),
     ],
 )
 class TestHelpFunctions: