From 5bf1bcb4d28632c74eca1336e91a97414c4d205d Mon Sep 17 00:00:00 2001
From: Matteo Cypriani <matteo.cypriani@uqat.ca>
Date: Fri, 14 Jun 2013 12:42:07 -0400
Subject: [PATCH] Handle aggregation CSV format version

The first field of the Aggregator's CSV output files is now an unsigned
integer that announces the version of the CSV format used. Current
version is 1 and the subsequent fields are not modified, so that an
aggregation file generated with a previous version can still be used by
adding "1;" at the beginning of each line.

The Positioner has been adapted to handle this new format.
---
 TODO.t2t                             |  7 -------
 libowlps/owlps.h                     |  6 ++++++
 owlps-aggregator/owlps-aggregatord.c |  3 +++
 owlps-positioner/inputcsv.cc         | 22 ++++++++++++++++++++++
 owlps-positioner/inputcsv.hh         |  5 +++--
 owlps-positioner/request.cc          |  6 ++++++
 6 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/TODO.t2t b/TODO.t2t
index 0617834..33914d0 100644
--- a/TODO.t2t
+++ b/TODO.t2t
@@ -21,13 +21,6 @@ Work to do in OwlPS
 - Known bugs:
   - libconfuse bug (Listener & Aggregator): http://bugs.debian.org/639115
 
-- Handle the aggregation format version
-
-  In the aggregation files, a version number describing the file format
-  should be added (as the 2nd field, right after the client's MAC
-  address). That would allow the positioning server to handle several
-  formats instead of just the last version.
-
 - Add a library to parse aggregation files, handling the different
   formats ?
 
diff --git a/libowlps/owlps.h b/libowlps/owlps.h
index 9758440..287729e 100644
--- a/libowlps/owlps.h
+++ b/libowlps/owlps.h
@@ -61,6 +61,12 @@ extern "C" {
 //@}
 
 
+/** @name Miscellaneous informations */
+//@{
+#define OWL_LATEST_AGGREGATION_CSV_FORMAT 1
+//@}
+
+
 /// Directions
 enum owl_directions
 {
diff --git a/owlps-aggregator/owlps-aggregatord.c b/owlps-aggregator/owlps-aggregatord.c
index 311781d..821858b 100644
--- a/owlps-aggregator/owlps-aggregatord.c
+++ b/owlps-aggregator/owlps-aggregatord.c
@@ -1000,6 +1000,9 @@ void output_request(request_list *const request_ptr,
   owl_request_info info;
   request_info_list *request_info_ptr = NULL ;
 
+  // Print CSV format version to the output file
+  fprintf(stream, "%d;", OWL_LATEST_AGGREGATION_CSV_FORMAT) ;
+
   // Print mobile MAC address to the output file
   owl_mac_bytes_to_string_r(request_ptr->mobile_mac_addr_bytes,
                             mac_str) ;
diff --git a/owlps-positioner/inputcsv.cc b/owlps-positioner/inputcsv.cc
index fd2ab55..04e805b 100644
--- a/owlps-positioner/inputcsv.cc
+++ b/owlps-positioner/inputcsv.cc
@@ -44,6 +44,28 @@ bool InputCSV::fill_current_request()
     return false ;
   ++current_line_nb ;
 
+  // Read CSV format version
+  uint_fast16_t csv_format_version ;
+  if (! file.read_field(csv_format_version))
+    {
+      // Wrong number of fields
+      if (Configuration::is_configured("verbose"))
+        cerr << "InputCSV: cannot read the CSV format version.\n" ;
+      return false ;
+    }
+
+  // Check the CSV format
+  switch (csv_format_version)
+    {
+    case 1 :
+      // Format 1 is the only one we handle for now.
+      break ;
+    default :
+      cerr << "InputCSV: CSV format version " << csv_format_version
+           << " is not handled!\n" ;
+      return false ;
+    }
+
   // Read Mobile MAC field
   string mac_mobile ;
   if (! file.read_field(mac_mobile)) // Wrong number of fields
diff --git a/owlps-positioner/inputcsv.hh b/owlps-positioner/inputcsv.hh
index bd17fe5..880e2ef 100644
--- a/owlps-positioner/inputcsv.hh
+++ b/owlps-positioner/inputcsv.hh
@@ -23,8 +23,9 @@
 /// Reads [requests](@ref Request) from a CSV file
 /**
  * CSV format is:
- *   Mobile_MAC;Request_type;Number_of_packets;Timestamp;X;Y;Z;Direction;
- *     AP_MAC_1;Packet_ID_1;SS_1;…;AP_MAC_n;Packet_ID_n;SS_n
+ *     Format_version;Mobile_MAC;Request_type;Number_of_packets;
+ *     Timestamp;X;Y;Z;Direction;AP_MAC_1;Packet_ID_1;SS_1;…;
+ *     AP_MAC_n;Packet_ID_n;SS_n
  */
 class InputCSV: public InputMedium
 {
diff --git a/owlps-positioner/request.cc b/owlps-positioner/request.cc
index 9aa0b84..5e499b0 100644
--- a/owlps-positioner/request.cc
+++ b/owlps-positioner/request.cc
@@ -210,6 +210,12 @@ const string Request::to_csv() const
 {
   ostringstream csv_line ;
 
+  // CSV format version
+  // (this should match OWL_LATEST_AGGREGATION_CSV_FORMAT)
+  constexpr unsigned int aggregation_csv_format = 1 ;
+
+  csv_line << aggregation_csv_format << ';' ;
+
   if (mobile != NULL)
     csv_line << mobile->get_mac_addr() ;