#1: Refactor _cffi_api_util.py module into a class to reduce code redundancy between classic and PM versions.

Author: PMeira

dss/_cffi_api_util.py

@@ -1,5 +1,4 @@
 from __future__ import absolute_import
-from ._dss_capi import lib, ffi
 import numpy as np
 
 freeze = True
@@ -41,99 +40,97 @@ def __getattr__(self, key):
 
 
     def __setattr__(self, key, value):
-        
         if _case_insensitive:
             okey = key
             key = self._dss_atributes.get(key.lower(), None)
             if key is None:
-                raise TypeError( "%r is a frozen class" % self)
+                raise TypeError("%r is a frozen class" % self)
 
         if self._isfrozen and not hasattr(self, key):
-            raise TypeError( "%r is a frozen class" % self )
+            raise TypeError("%r is a frozen class" % self)
 
         object.__setattr__(self, key, value)
 
 
-def get_string(b):
-    return ffi.string(b).decode(codec)
-    
-def get_float64_array(func, *args):
-    ptr = ffi.new('double**')
-    cnt = ffi.new('int32_t*')
-    func(ptr, cnt, *args)
-    if not cnt[0]:
-        res = None
-    else:
-        res = np.frombuffer(ffi.buffer(ptr[0], cnt[0] * 8), dtype=np.float).copy()
 
-    lib.DSS_Dispose_PDouble(ptr)
-    return res
+class CffiApiUtil(object):
+    def __init__(self, ffi, lib):
+        self.ffi = ffi
+        self.lib = lib
 
-    
-    
-def get_int32_array(func, *args):
-    ptr = ffi.new('int32_t**')
-    cnt = ffi.new('int32_t*')
-    func(ptr, cnt, *args)
-    if not cnt[0]:
-        res = None
-    else:
-        res = np.frombuffer(ffi.buffer(ptr[0], cnt[0] * 4), dtype=np.int32).copy()
-    
-    lib.DSS_Dispose_PInteger(ptr)
-    return res
+    def get_string(self, b):
+        return self.ffi.string(b).decode(codec)
 
+    def get_float64_array(self, func, *args):
+        ptr = self.ffi.new('double**')
+        cnt = self.ffi.new('int32_t*')
+        func(ptr, cnt, *args)
+        if not cnt[0]:
+            res = None
+        else:
+            res = np.frombuffer(self.ffi.buffer(ptr[0], cnt[0] * 8), dtype=np.float).copy()
+
+        self.lib.DSS_Dispose_PDouble(ptr)
+        return res
 
-def get_int8_array(func, *args):
-    ptr = ffi.new('int8_t**')
-    cnt = ffi.new('int32_t*')
-    func(ptr, cnt, *args)
-    if not cnt[0]:
-        res = None
-    else:
-        res = np.frombuffer(ffi.buffer(ptr[0], cnt[0] * 1), dtype=np.int8).copy()
-    
-    lib.DSS_Dispose_PByte(ptr)
-    return res
-    
+    def get_int32_array(self, func, *args):
+        ptr = self.ffi.new('int32_t**')
+        cnt = self.ffi.new('int32_t*')
+        func(ptr, cnt, *args)
+        if not cnt[0]:
+            res = None
+        else:
+            res = np.frombuffer(self.ffi.buffer(ptr[0], cnt[0] * 4), dtype=np.int32).copy()
+        
+        self.lib.DSS_Dispose_PInteger(ptr)
+        return res
+            
+    def get_int8_array(self, func, *args):
+        ptr = self.ffi.new('int8_t**')
+        cnt = self.ffi.new('int32_t*')
+        func(ptr, cnt, *args)
+        if not cnt[0]:
+            res = None
+        else:
+            res = np.frombuffer(self.ffi.buffer(ptr[0], cnt[0] * 1), dtype=np.int8).copy()
 
-def get_string_array(func, *args):
-    ptr = ffi.new('char***')
-    cnt = ffi.new('int32_t*')
-    func(ptr, cnt, *args)
-    if not cnt[0]:
-        res = []
-    else:
-        actual_ptr = ptr[0]
-        if actual_ptr == ffi.NULL:
+        self.lib.DSS_Dispose_PByte(ptr)
+        return res
+            
+    def get_string_array(self, func, *args):
+        ptr = self.ffi.new('char***')
+        cnt = self.ffi.new('int32_t*')
+        func(ptr, cnt, *args)
+        if not cnt[0]:
             res = []
         else:
-            res = [(str(ffi.string(actual_ptr[i]).decode(codec)) if (actual_ptr[i] != ffi.NULL) else None) for i in range(cnt[0])]
-    
-    lib.DSS_Dispose_PPAnsiChar(ptr, cnt[0])
-    return res
-    
-    
-    
-def prepare_float64_array(value):
-    if type(value) is not np.ndarray or value.dtype != np.float64:
-        value = np.array(value, dtype=np.float64)
-    
-    ptr = ffi.cast('double*', ffi.from_buffer(data.data))
-    cnt = data.size
-    return value, ptr, cnt
-   
-def prepare_int32_array(value):
-    if type(value) is not np.ndarray or value.dtype != np.int32:
-        value = np.array(value, dtype=np.int32)
-    
-    ptr = ffi.cast('int32_t*', ffi.from_buffer(data.data))
-    cnt = data.size
-    return value, ptr, cnt
-   
+            actual_ptr = ptr[0]
+            if actual_ptr == self.ffi.NULL:
+                res = []
+            else:
+                res = [(str(self.ffi.string(actual_ptr[i]).decode(codec)) if (actual_ptr[i] != self.ffi.NULL) else None) for i in range(cnt[0])]
+        
+        self.lib.DSS_Dispose_PPAnsiChar(ptr, cnt[0])
+        return res
+        
+    def prepare_float64_array(self, value):
+        if type(value) is not np.ndarray or value.dtype != np.float64:
+            value = np.array(value, dtype=np.float64)
+        
+        ptr = self.ffi.cast('double*', self.ffi.from_buffer(data.data))
+        cnt = data.size
+        return value, ptr, cnt
+       
+    def prepare_int32_array(self, value):
+        if type(value) is not np.ndarray or value.dtype != np.int32:
+            value = np.array(value, dtype=np.int32)
+        
+        ptr = self.ffi.cast('int32_t*', self.ffi.from_buffer(data.data))
+        cnt = data.size
+        return value, ptr, cnt
 
-def prepare_string_array(value):
-    raise NotImplementedError
+    def prepare_string_array(self, value):
+        raise NotImplementedError
 
 
 # This might be useful for methods like Get_Channel that are exposed as Channel[] and Channel()

dss/dss_capi.py

@@ -4,10 +4,21 @@
 Copyright (c) 2016-2018 Paulo Meira
 '''
 from __future__ import absolute_import
-from ._dss_capi import lib, ffi
-from ._cffi_api_util import * # one for each version (parallel, classic), already bound to the cffi module
+from ._dss_capi import ffi, lib
+from ._cffi_api_util import *
 import numpy as np
 
+# Bind to the FFI module instance for OpenDSS-Classic
+api_util = CffiApiUtil(ffi, lib)
+get_string = api_util.get_string
+get_float64_array = api_util.get_float64_array
+get_int32_array = api_util.get_int32_array
+get_int8_array = api_util.get_int8_array
+get_string_array = api_util.get_string_array
+prepare_float64_array = api_util.prepare_float64_array
+prepare_int32_array = api_util.prepare_int32_array
+prepare_string_array = api_util.prepare_string_array
+
 if not freeze:
     FrozenClass = object
 

dss/pm/_cffi_api_util.py

@@ -4,10 +4,21 @@
 Copyright (c) 2016-2018 Paulo Meira
 '''
 from __future__ import absolute_import
-from .._dsspm_capi import lib, ffi
-from ._cffi_api_util import * # one for each version (parallel, classic), already bound to the cffi module
+from .._dsspm_capi import ffi, lib
+from .._cffi_api_util import *
 import numpy as np
 
+# Bind to the FFI module instance for OpenDSS-PM
+api_util = CffiApiUtil(ffi, lib)
+get_string = api_util.get_string
+get_float64_array = api_util.get_float64_array
+get_int32_array = api_util.get_int32_array
+get_int8_array = api_util.get_int8_array
+get_string_array = api_util.get_string_array
+prepare_float64_array = api_util.prepare_float64_array
+prepare_int32_array = api_util.prepare_int32_array
+prepare_string_array = api_util.prepare_string_array
+
 if not freeze:
     FrozenClass = object