Automatic replacement of snapshot_prefix parameter if it is empty or …

…points to a directory. See issue BVLC#6110 proposed improvement No.2

src/caffe/proto/caffe.proto

@@ -186,7 +186,11 @@ message SolverParameter {
   optional float clip_gradients = 35 [default = -1];
 
   optional int32 snapshot = 14 [default = 0]; // The snapshot interval
-  optional string snapshot_prefix = 15; // The prefix for the snapshot.
+  // The prefix for the snapshot.
+  // If not set then is replaced by prototxt file path without extention.
+  // If is set to directory then is augmented by prototxt file name
+  // without extention.
+  optional string snapshot_prefix = 15;
   // whether to snapshot diff in the results or not. Snapshotting diff will help
   // debugging but the final protocol buffer size will be much larger.
   optional bool snapshot_diff = 16 [default = false];

src/caffe/util/upgrade_proto.cpp

@@ -2,6 +2,8 @@
 #include <google/protobuf/io/zero_copy_stream_impl.h>
 #include <google/protobuf/text_format.h>
 
+#include <boost/filesystem.hpp>
+
 #include <map>
 #include <string>
 
@@ -1095,12 +1097,31 @@ bool UpgradeSolverAsNeeded(const string& param_file, SolverParameter* param) {
   return success;
 }
 
+// Replaces snapshot_prefix of SolverParameter if it is not specified
+// or is set to directory
+void UpgradeSnapshotPrefixProperty(const string& param_file,
+                                   SolverParameter* param) {
+  using boost::filesystem::path;
+  using boost::filesystem::is_directory;
+  if (!param->has_snapshot_prefix()) {
+    param->set_snapshot_prefix(path(param_file).replace_extension().string());
+    LOG(INFO) << "snapshot_prefix was not specified and is set to "
+                + param->snapshot_prefix();
+  } else if (is_directory(param->snapshot_prefix())) {
+    param->set_snapshot_prefix((path(param->snapshot_prefix()) /
+                               path(param_file).stem()).string());
+    LOG(INFO) << "snapshot_prefix was a directory and is replaced to "
+                + param->snapshot_prefix();
+  }
+}
+
 // Read parameters from a file into a SolverParameter proto message.
 void ReadSolverParamsFromTextFileOrDie(const string& param_file,
                                        SolverParameter* param) {
   CHECK(ReadProtoFromTextFile(param_file, param))
       << "Failed to parse SolverParameter file: " << param_file;
   UpgradeSolverAsNeeded(param_file, param);
+  UpgradeSnapshotPrefixProperty(param_file, param);
 }
 
 }  // namespace caffe