Lazy init of host interface

Author: Shillaker

cfaasm/tester.py

@@ -24,7 +24,7 @@
 _host_interface = None
 
 
-def init_host_interface():
+def _init_host_interface():
     global _host_interface
 
     if _host_interface is None:
@@ -48,6 +48,7 @@ def set_local_input_output(value):
 
 
 def read_input():
+    _init_host_interface()
     return _host_interface.__faasm_read_input()
 
 
@@ -56,6 +57,7 @@ def write_output(output):
         global output_data
         output_data = output
     else:
+        _init_host_interface()
         _host_interface.__faasm_write_output(output)
 
 
@@ -70,10 +72,12 @@ def get_output():
 
 
 def read_state_size(key):
+    _init_host_interface()
     return _host_interface.__faasm_read_state(bytes(key, "utf-8"), None, 0)
 
 
 def read_state(key, state_len):
+    _init_host_interface()
     state_len = int(state_len)
     buff = ctypes.create_string_buffer(state_len)
     _host_interface.__faasm_read_state(bytes(key, "utf-8"), buff, state_len)
@@ -82,6 +86,7 @@ def read_state(key, state_len):
 
 
 def read_state_offset(key, total_len, offset, offset_len):
+    _init_host_interface()
     total_len = int(total_len)
     offset_len = int(offset_len)
     buff = ctypes.create_string_buffer(offset_len)
@@ -93,10 +98,12 @@ def read_state_offset(key, total_len, offset, offset_len):
 
 
 def write_state(key, value):
+    _init_host_interface()
     _host_interface.__faasm_write_state(bytes(key, "utf-8"), value, len(value))
 
 
 def write_state_offset(key, total_len, offset, value):
+    _init_host_interface()
     offset = int(offset)
     total_len = int(total_len)
 
@@ -106,14 +113,17 @@ def write_state_offset(key, total_len, offset, value):
 
 
 def push_state(key):
+    _init_host_interface()
     _host_interface.__faasm_push_state(bytes(key, "utf-8"))
 
 
 def push_state_partial(key):
+    _init_host_interface()
     _host_interface.__faasm_push_state_partial(bytes(key, "utf-8"))
 
 
 def pull_state(key, state_len):
+    _init_host_interface()
     state_len = int(state_len)
     _host_interface.__faasm_pull_state(bytes(key, "utf-8"), state_len)
 
@@ -124,7 +134,9 @@ def chain(func, input_data):
         func(input_data)
         return 0
     else:
-        # Call native
+        # Call into host interface
+        _init_host_interface()
+
         func_name = func.__name__
         return _host_interface.__faasm_chain_py(
             bytes(func_name, "utf-8"), input_data, len(input_data)
@@ -133,14 +145,16 @@ def chain(func, input_data):
 
 def await_call(call_id):
     if PYTHON_LOCAL_CHAINING:
-        # Calls are run immediately
+        # Calls are run immediately in local chaining
         return 0
     else:
-        # Call native
+        _init_host_interface()
         return _host_interface.__faasm_await_call(call_id)
 
 
 def set_emulator_message(message_json):
+    _init_host_interface()
+
     message_bytes = bytes(message_json, "utf-8")
     if PYTHON_LOCAL_OUTPUT:
         global output_data
@@ -150,8 +164,10 @@ def set_emulator_message(message_json):
 
 
 def set_emulator_status(success):
+    _init_host_interface()
     _host_interface.__set_emulator_status(success)
 
 
 def get_emulator_async_response():
+    _init_host_interface()
     return _host_interface.__get_emulator_async_response()

pyfaasm/core

@@ -1,7 +1,6 @@
 from pyfaasm.core import (
     read_state,
     read_state_offset,
-    init_host_interface,
     write_state,
     write_state_offset,
     push_state,
@@ -10,8 +9,6 @@
 )
 import json
 
-init_host_interface()
-
 msg = {
     "user": "demo",
     "function": "echo",