add merge model tools

python/paddle/utils/merge_model.py

+# Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import gzip
+import struct
+import os
+
+from paddle.trainer_config_helpers.layers import LayerOutput
+from paddle.v2.parameters import Parameters
+from paddle.proto import ModelConfig_pb2
+from paddle.v2.topology import Topology
+
+def merge_model(net_out, param_file, output_file):
+    '''Integrate the model config and model parameters into one file.
+    
+    The model configuration file describes the model structure which
+    ends with .py. The parameters file stores the parameters of the model
+    which ends with .tar.gz.
+    
+    @param  net_out       the output layer of the network 
+    @param  param_file     path of the model parameters file(a gzip file).
+    @param  output_file   path of the merged file which will be generated
+    
+    Usage:
+
+        from paddle.util.merge_model import merge_model
+        # import your network configuration
+        from mobilenet import mobile_net
+        
+        net_out = mobile_net(3*224*224, 102)
+        param_file = YOUR_MODEL_PARAM_PATH
+        output_file = OUTPUT_MERGED_FILE_PATH
+        
+        merge_model(net_out, param_file, output_file)
+
+    '''
+
+    assert isinstance(net_out, LayerOutput), \
+            "The net_out should be the output of the network"
+    assert os.path.exists(param_file), \
+            "The model parameters file %s does not exists " % (param_file)
+
+    model_proto = Topology(net_out).proto()
+    assert isinstance(model_proto, ModelConfig_pb2.ModelConfig)
+
+    with gzip.open(param_file) as f: 
+        params = Parameters.from_tar(f) 
+
+    if os.path.exists(output_file):
+        os.remove(output_file)
+
+    with open(output_file, 'w') as f:
+        param_names = [param.name for param in model_proto.parameters]
+        conf_str = model_proto.SerializeToString()
+        f.write(struct.pack('q', len(conf_str)))
+        f.write(conf_str)
+        for pname in param_names:
+            params.serialize(pname, f)
+
+    print 'Generate  %s  success!' % (output_file)