don't clone the input program in default when connect program

paddle_hub/tools/paddle_helper.py

@@ -120,7 +120,7 @@ def from_flexible_data_to_param(flexible_data):
     return param
 
 
-def connect_program(pre_program, next_program, input_dict=None):
+def connect_program(pre_program, next_program, input_dict=None, inplace=True):
     def _copy_vars_and_ops_in_blocks(from_block, to_block):
         for var in from_block.vars:
             var = from_block.var(var)
@@ -149,7 +149,8 @@ def connect_program(pre_program, next_program, input_dict=None):
                       fluid.Program), "pre_program should be fluid.Program"
     assert isinstance(next_program,
                       fluid.Program), "next_program should be fluid.Program"
-    new_program = pre_program.clone()
+    output_program = pre_program if inplace else pre_program.clone(
+        for_test=False)
     if input_dict:
         assert isinstance(
             input_dict,
@@ -159,11 +160,11 @@ def connect_program(pre_program, next_program, input_dict=None):
                 var, fluid.framework.Variable
             ), "the input_dict should be a dict with string-Variable pair"
             var_info = copy.deepcopy(get_variable_info(var))
-            input_var = new_program.global_block().create_var(**var_info)
+            input_var = output_program.global_block().create_var(**var_info)
             output_var = next_program.global_block().var(key)
             var_info = copy.deepcopy(get_variable_info(output_var))
-            output_var = new_program.global_block().create_var(**var_info)
-            new_program.global_block().append_op(
+            output_var = output_program.global_block().create_var(**var_info)
+            output_program.global_block().append_op(
                 type="assign",
                 inputs={'X': input_var},
                 outputs={'Out': output_var})
@@ -172,17 +173,17 @@ def connect_program(pre_program, next_program, input_dict=None):
     logger.info("start to connect program")
     for index, block in enumerate(next_program.blocks):
         if block.idx == 0:
-            _copy_vars_and_ops_in_blocks(block, new_program.global_block())
+            _copy_vars_and_ops_in_blocks(block, output_program.global_block())
         else:
-            block_map[index] = len(new_program.blocks)
+            block_map[index] = len(output_program.blocks)
             logger.info(
                 "block_%d in next_program merge into block_%d in pre_program" %
                 (index, block_map[index]))
-            new_block = new_program._create_block(
+            new_block = output_program._create_block(
                 parent_idx=block_map[block.parent_idx])
             _copy_vars_and_ops_in_blocks(block, new_block)
     logger.info("end of connect program")
-    return new_program
+    return output_program
 
 
 def remove_feed_fetch_op(program):