feat: Move transport call() functionality to _call()

Instead of having transports override the base class's call method
directly, instead it will call the _call method and subclassess should
override it instead. This paves the way for adding consistent base
functionality across transports.

Author: kadler

src/itoolkit/transport/base.py

@@ -35,4 +35,10 @@ def call(self, tk):
         Returns:
           str: The XML returned from XMLSERVICE
         """
+        return self._call(tk)
+
+    def _call(self, tk):
+        """Called by :py:func:`call`. This should be overridden by subclasses
+        to the call function instead of overriding :py:func:`call` directly.
+        """
         raise NotImplementedError

src/itoolkit/transport/database.py

@@ -67,7 +67,7 @@ def __init__(self, conn, **kwargs):
             ('proc', 'procedure')
         ])
 
-    def call(self, tk):
+    def _call(self, tk):
         cursor = self.conn.cursor()
 
         parms = (self.ipc, self.ctl, tk.xml_in())

src/itoolkit/transport/direct.py

@@ -27,7 +27,7 @@ class DirectTransport(XmlServiceTransport):
     def __init__(self, **kwargs):
         super(DirectTransport, self).__init__(**kwargs)
 
-    def call(self, tk):
+    def _call(self, tk):
         try:
             data = _direct.xmlservice(tk.xml_in(), self.ctl, self.ipc)
 

src/itoolkit/transport/http.py

@@ -48,7 +48,7 @@ def __init__(self, url, user, password, database='*LOCAL', **kwargs):
 
     OUT_SIZE = 16 * 1000 * 1000
 
-    def call(self, tk):
+    def _call(self, tk):
         data = urlencode({
             'db2': self.db,
             'uid': self.uid,

src/itoolkit/transport/ssh.py

@@ -64,7 +64,7 @@ def __init__(self, sshclient=None, **kwargs):
 
         self.conn = sshclient
 
-    def call(self, tk):
+    def _call(self, tk):
         """Call xmlservice with accumulated input XML.
 
         Args: