[UDP-HTTP] Handle new request "ReadResults"

owlps-udp-to-http/owlps-udp-to-http.c

@@ -14,7 +14,29 @@
  * Only the last result read from the positioning server, for each
  * mobile, is memorised and provided to the HTTP client.
  *
- * The only HTTP request currently implemented is "ReadSimpleResults".
+ * The HTTP requests currently implemented are listed bellow.
+ *
+ * ** Request "ReadResults" **
+ * Answer in case of error:
+ *   Results;NOK;Explanation
+ * Normal answer:
+ *   Results;OK;Nb_results;Result_1;…;Result_n
+ * Nb_results is the number of results in the answer (number of mobiles).
+ * Result_i follows this format:
+ *   Mobile_MAC;Request_type;Request_timestamp;Nb_algo;Algo_1;…;Algo_n
+ * Nb_algo is the number of algorithms in the result.
+ * Algo_i follows this format:
+ *   Algorithm_name;X;Y;Z;Error;Area_name
+ * Error is the distance from the true coordinates of the mobile, if
+ * known; if unknown, Error is set to -1.
+ * Area_name is the name of the area or room in which the mobile is (may
+ * be empty).
+ *
+ * ** Unknown request **
+ * If a unknown request is received, the answer format is:
+ *   UnknownRequest;NOK
+ *
+ * ** Request "ReadSimpleResults" **
  * Answer in case of error:
  *   SimpleResults;NOK;Explanation
  * Normal answer:
@@ -24,9 +46,6 @@
  *   Mobile_MAC;X;Y;Z;Area_name
  * Area_name is the name of the area or room in which the mobile is (may
  * be empty).
- *
- * If a unknown request is received, the answer format is:
- *   UnknownRequest;NOK
  */
 
 #include "owlps-udp-to-http.h"
@@ -293,6 +312,14 @@ extract_request_from_message(char client_request[CLIENT_REQUEST_STRLEN],
       return SIMPLE_RESULTS_ID ;
     }
 
+  if (strncmp(RESULTS_REQUEST, token,
+              strlen(RESULTS_REQUEST)) == 0)
+    {
+      strncpy(client_request, RESULTS_REQUEST,
+              CLIENT_REQUEST_STRLEN) ;
+      return RESULTS_ID ;
+    }
+
   return 0 ; // No known request found
 }
 
@@ -307,6 +334,56 @@ void prepare_answer(int request_id)
 
   switch (request_id)
     {
+    case RESULTS_ID:
+      strncpy(answer + answer_strlen, RESULTS_ANSWER,
+              strlen(RESULTS_ANSWER)) ;
+      answer_strlen += strlen(RESULTS_ANSWER) ;
+
+      sem_wait(&lock_results) ;
+
+      if (! results)
+        {
+          char answer_end[] = ";NOK;NoResult" ;
+          strncpy(answer + answer_strlen, answer_end,
+                  strlen(answer_end)) ;
+          answer_strlen += strlen(answer_end) ;
+        }
+
+      else
+        {
+          results_list *result ;
+          char answer_begin[10] ;
+          size_t answer_begin_len ;
+
+          snprintf(answer_begin, 10, ";OK;%u", nb_results) ;
+          answer_begin_len = strlen(answer_begin) ;
+          strncpy(answer + answer_strlen, answer_begin,
+                  answer_begin_len) ;
+          answer_strlen += answer_begin_len ;
+
+          realloc_answer(answer_strlen +
+                         nb_results * OWL_CSV_RESULT_STRLEN) ;
+
+          result = results ;
+          while (result != NULL)
+            {
+              char result_str[OWL_CSV_RESULT_STRLEN] ;
+              size_t result_len ;
+              owl_result_to_csv(result_str, result->result) ;
+              result_len = strlen(result_str) ;
+              answer[answer_strlen++] = ';' ;
+              assert(answer_strlen<answer_buflen) ;
+              strncpy(answer + answer_strlen, result_str,
+                      result_len) ;
+              answer_strlen += result_len ;
+              result = result->next ;
+            }
+        }
+
+      sem_post(&lock_results) ;
+
+      break ;
+
     case SIMPLE_RESULTS_ID:
       strncpy(answer + answer_strlen, SIMPLE_RESULTS_ANSWER,
               strlen(SIMPLE_RESULTS_ANSWER)) ;

owlps-udp-to-http/owlps-udp-to-http.h

@@ -7,10 +7,13 @@
 #define NB_CONNECTIONS 1
 #define CLIENT_MESSAGE_STRLEN 2500
 
+#define CLIENT_REQUEST_STRLEN 21
 #define SIMPLE_RESULTS_ID 1
 #define SIMPLE_RESULTS_REQUEST "ReadSimpleResults"
 #define SIMPLE_RESULTS_ANSWER "SimpleResults"
-#define CLIENT_REQUEST_STRLEN 21
+#define RESULTS_ID 2
+#define RESULTS_REQUEST "ReadResults"
+#define RESULTS_ANSWER "Results"
 
 #ifndef OWLPS_VERSION
 # define OWLPS_VERSION "unknown version"