Add request parsing helper, add TIMEVAL_* macros, move timestamps to identify module
[matches/MCTX3420.git] / server / sensor.c
index 3d5aec7..f2c73c5 100644 (file)
@@ -35,7 +35,7 @@ DataPoint * GetData(SensorId sensor_id, DataPoint * d)
        
        struct timeval t;
        gettimeofday(&t, NULL);
-       d->time_stamp = (t.tv_sec - g_options.start_time.tv_sec) + 1e-6*(t.tv_usec - g_options.start_time.tv_usec);
+       d->time_stamp = TIMEVAL_DIFF(t, g_options.start_time);
 
        // Make time relative
        //d->time_stamp.tv_sec -= g_options.start_time.tv_sec;
@@ -45,6 +45,8 @@ DataPoint * GetData(SensorId sensor_id, DataPoint * d)
        {
                case ANALOG_TEST0:
                {
+                       //CheckSensor( sensor_id, *sensor value*); 
+               
                        static int count = 0;
                        d->value = count++;
                        break;
@@ -69,6 +71,33 @@ DataPoint * GetData(SensorId sensor_id, DataPoint * d)
        return d;
 }
 
+/**
+ * Checks the sensor data for unsafe or unexpected results 
+ * @param sensor_id - The ID of the sensor
+ *
+*
+void CheckSensor( SensorId sensor_id)
+{
+       switch (sensor_id)
+       {
+               case ANALOG_TEST0:
+               {
+                       if( *sensor value* > ANALOG_TEST0_SAFETY)
+                       {
+                               LogEx(LOGERR, GetData, Sensor analog_test0 is above the safe value);
+                       //new log function that stops actuators?
+                       }
+                       //Also include a warning level?
+                       else if( *sensor value* > ANALOG_TEST0_WARN)
+                       {
+                               LogEx(LOGWARN, GetData, Sensor analog_test0);   
+                       }
+               }
+       }
+               
+       
+*/     
+
 
 /**
  * Destroy a sensor
@@ -90,6 +119,8 @@ void Init(Sensor * s, int id)
 {
        s->write_index = 0;
        s->id = id;
+       s->points_written = 0;
+       s->points_read = 0;
 
        #define FILENAMESIZE 3
        char filename[FILENAMESIZE];
@@ -135,7 +166,6 @@ void * Sensor_Main(void * arg)
                                Fatal("Error collecting data");
                        }
                        s->write_index += 1;
-                       //TODO: s->points_read not used?
                }
 
                //Log(LOGDEBUG, "Filled buffer");
@@ -150,7 +180,7 @@ void * Sensor_Main(void * arg)
                        {
                                Fatal("Wrote %d data points and expected to write %d to \"%s\" - %s", amount_written, SENSOR_DATABUFSIZ, strerror(errno));
                        }
-                       s->points_stored += amount_written;
+                       s->points_written += amount_written;
                        //Log(LOGDEBUG, "Wrote %d data points for sensor %d", amount_written, s->id);
                pthread_mutex_unlock(&(s->mutex));
                // End of critical section
@@ -162,8 +192,135 @@ void * Sensor_Main(void * arg)
        return NULL; 
 }
 
+/**
+ * Get position in a binary sensor file with a timestamp using a binary search
+ * @param s - Sensor to use
+ * @param time_stamp - Timestamp
+ * @param count - If not NULL, used to provide number of searches required
+ * @param found - If not NULL, set to the closest DataPoint
+ * @returns Integer giving the *closest* index in the file
+ * TODO: Refactor or replace?
+ */
+int FindTime(Sensor * s, double time_stamp, int * count, DataPoint * found)
+{
+       DataPoint d;
+
+       int lower = 0;
+       int upper = s->points_written - 1;
+       int index = 0;
+       if (count != NULL)
+               *count = 0;     
+
+       while (upper - lower > 1)
+       {
+               index = lower + ((upper - lower)/2);
+
+               // Basically anything with fseek is critical; if we don't make it critical the sensor thread may alter data at a random point in the file!
+               // CRITICAL SECTION (May need to rethink how this is done, but I can't see how to do it without fseek :S)
+               // Regarding the suggestion that we have 2 file pointers; one for reading and one for writing:
+               // That seems like it will work... but we will have to be very careful and test it first
+               pthread_mutex_lock(&s->mutex);
+                       fseek(s->file, index*sizeof(DataPoint), SEEK_SET);
+                       int amount_read = fread(&d, sizeof(DataPoint), 1, s->file);
+               pthread_mutex_unlock(&s->mutex);
+               
+               if (amount_read != 1)
+               {
+                       Fatal("Couldn't read single data point from sensor %d", s->id);
+               }
+
+               if (d.time_stamp > time_stamp)
+               {
+                       upper = index;
+               }
+               else if (d.time_stamp < time_stamp)
+               {
+                       lower = index;
+               }
+               if (count != NULL)
+                       *count += 1;
+       }
+
+       if (found != NULL)
+               *found = d;
+
+       return index;
+       
+}
+
+/**
+ * Print sensor data between two indexes in the file, using a given format
+ * @param s - Sensor to use
+ * @param start - Start index
+ * @param end - End index
+ * @param output_type - JSON, CSV or TSV output format
+ */
+void PrintData(Sensor * s, int start, int end, OutputType output_type)
+{
+       DataPoint buffer[SENSOR_QUERYBUFSIZ];
+       int index = start;
+
+       if (output_type == JSON)
+       {
+               FCGI_JSONValue("[");
+       }
+
+
+       while (index < end)
+       {
+               int to_read = end - index;
+               if (to_read > SENSOR_QUERYBUFSIZ)
+               {
+                       to_read = SENSOR_QUERYBUFSIZ;
+               }
+
+               int amount_read = 0;
+               // CRITICAL SECTION
+               pthread_mutex_lock(&(s->mutex));
+
+                       fseek(s->file, index*sizeof(DataPoint), SEEK_SET);
+                       amount_read = fread(buffer, sizeof(DataPoint), to_read, s->file);
+
+               pthread_mutex_unlock(&(s->mutex));
+               // End critical section
+
+               if (amount_read != to_read)
+               {
+                       Fatal("Failed to read %d DataPoints from sensor %d; read %d instead", to_read, s->id, amount_read);
+               }
+
+               // Print the data
+               for (int i = 0; i < amount_read; ++i)
+               {
+                       //TODO: Reformat?
+                       switch (output_type)
+                       {
+                               case JSON:
+                                       FCGI_JSONValue("[%f, %f]", buffer[i].time_stamp, buffer[i].value);
+                                       if (i+1 < amount_read)
+                                               FCGI_JSONValue(",");
+                                       break;
+                               case CSV:
+                                       FCGI_PrintRaw("%f,%f\n", buffer[i].time_stamp, buffer[i].value);
+                                       break;
+                               case TSV:
+                               default:
+                                       FCGI_PrintRaw("%f\t%f\n", buffer[i].time_stamp, buffer[i].value);
+                                       break;
+                       }
+               }
+               index += amount_read;
+       }
+
+       if (output_type == JSON)
+       {
+               FCGI_JSONValue("]");
+       }
+}
+
 /**
  * Fill buffer with most recent sensor data
+ * TODO: This may be obselete; remove?
  * @param s - Sensor to use
  * @param buffer - Buffer to fill
  * @param bufsiz - Size of buffer to fill
@@ -205,115 +362,47 @@ Sensor * Sensor_Identify(const char * id_str)
        return g_sensors+id;
 }
 
-/*
- * Behaviour: 
- * Dump true:
- * - from < 0: From beginning of file, else from that point onwards (0-indexed)
- * - count < 0: All points available, else *at most* that many points
- * Dump false:
- * - from < 0: From the end of file (last available points), else from that point onwards (0-indexed)
- * - count < 0: Default buffer size (SENSOR_QUERYBUFSIZ), else *at most* that many points
- */
-void Sensor_Handler2(FCGIContext *context, char *params)
-{
-       const char *key, *value;
-       int id = -1, from = -1, count = -1;
-       bool dump = false;
-
-       //Lazy checking
-       while ((params = FCGI_KeyPair(params, &key, &value))) {
-               if (!strcmp(key, "id") && *value) {
-                       char *end;
-                       id = strtol(value, &end, 10);
-                       if (*end != '\0')
-                               id = -1;
-               } else if (!strcmp(key, "dump")) {
-                       dump = !dump;
-               } else if (!strcmp(key, "from") && *value) {
-                       from = strtol(value, NULL, 10);
-               } else if (!strcmp(key, "count") && *value) {
-                       count = strtol(value, NULL, 10);
-               }
-       }
-
-       if (id < 0 || id >= NUMSENSORS) {
-               FCGI_RejectJSON(context, "Invalid sensor id specified.");
-               return;
-       }
-       
-       Sensor *sensor = &g_sensors[id];
-       DataPoint buffer[SENSOR_QUERYBUFSIZ];
-       int amount_read = 0, total = 0;
-       
-       //Critical section
-       pthread_mutex_lock(&(sensor->mutex));
-       if (from >= sensor->points_stored) {
-               FCGI_RejectJSONEx(context, STATUS_OUTOFRANGE, "Invalid range specified.");
-       } else if (dump) {
-               from =  (from < 0) ? 0 : from;
-               count = (count < 0) ? sensor->points_stored : count;
-
-               FCGI_PrintRaw("Content-type: text/plain\r\n"
-                       "Content-disposition: attachment;filename=%d.csv\r\n\r\n", id);
-
-               fseek(sensor->file, sizeof(DataPoint) * from, SEEK_SET);
-               //Force download with content-disposition
-               do {
-                       amount_read = fread(buffer, sizeof(DataPoint), SENSOR_QUERYBUFSIZ, sensor->file);
-                       for (int i = 0; i < amount_read && total < count; i++, total++) {
-                               FCGI_PrintRaw("%f\t%f\n", buffer[i].time_stamp, buffer[i].value);
-                       }
-               } while (amount_read > 0 && total < count);
-       } else {
-               count = (count < 0) ? SENSOR_QUERYBUFSIZ : count;
-               if (from < 0) {
-                       from = sensor->points_stored - count;
-                       if (from < 0)
-                               from = 0;
-               }
-               fseek(sensor->file, sizeof(DataPoint) * from, SEEK_SET);
-
-               FCGI_BeginJSON(context, STATUS_OK);     
-               FCGI_JSONLong("id", id); 
-               FCGI_JSONKey("data");
-               FCGI_JSONValue("[");
-               while (total < count) {
-                       amount_read = fread(buffer, sizeof(DataPoint), SENSOR_QUERYBUFSIZ, sensor->file);
-                       if (amount_read > 0) {
-                               FCGI_JSONValue("[%f, %f]", buffer[0].time_stamp, buffer[0].value);
-                               total++;
-                               for (int i = 1; i < amount_read && total < count; i++, total++)
-                                       FCGI_JSONValue(", [%f, %f]", buffer[i].time_stamp, buffer[i].value);
-                       } else {
-                               break;
-                       }
-               }
-               FCGI_JSONValue("]");
-
-               FCGI_JSONLong("total_points", sensor->points_stored);
-               FCGI_JSONLong("next_point", from + total);
-               FCGI_EndJSON(); 
-       }
-       pthread_mutex_unlock(&(sensor->mutex));
-       //End critical section
-}
-
 /**
  * Handle a request to the sensor module
  * @param context - The context to work in
  * @param params - Parameters passed
+ * TODO: Seriously need to write more helper functions and decrease the size of this function!
  */
 void Sensor_Handler(FCGIContext *context, char * params)
 {
-       DataPoint buffer[SENSOR_QUERYBUFSIZ];
        StatusCodes status = STATUS_OK;
 
-       enum {DEFAULT, DUMP} operation = DEFAULT;
+       OutputType output_type = JSON;
+       
+
 
        const char * key; const char * value;
 
        Sensor * sensor = NULL;
 
+       struct timeval now;
+       gettimeofday(&now, NULL);
+
+       double start_time = -1;
+       double end_time = -1;
+       double current_time = TIMEVAL_DIFF(now, g_options.start_time)
+       bool seek_time = false;
+       bool points_specified = false;
+       int query_size = SENSOR_QUERYBUFSIZ;
+       int start_index = -1;
+       int end_index = -1;
+
+       /* //Possible use case?
+       FCGIValue values[5] = {
+               {"id", &id, FCGI_REQUIRED(FCGI_INT_T)},
+               {"format", &format, FCGI_STRING_T},
+               {"points", &points, FCGI_STRING_T},
+               {"start_time", &start_time, FCGI_DOUBLE_T},
+               {"end_time", &end_time, FCGI_DOUBLE_T}
+       };
+       if (!FCGI_ParseRequest(context, params, values, 5))
+               return;*/
+
        while ((params = FCGI_KeyPair(params, &key, &value)) != NULL)
        {
                Log(LOGDEBUG, "Got key=%s and value=%s", key, value);
@@ -340,15 +429,78 @@ void Sensor_Handler(FCGIContext *context, char * params)
                                break;
                        }
                }
-               else if (strcmp(key, "dump") == 0)
+               else if (strcmp(key, "format") == 0)
                {
-                       if (operation != DEFAULT)
+                       if (strcmp(value, "json") == 0)
+                               output_type = JSON;
+                       else if (strcmp(value, "csv") == 0)
+                               output_type = CSV;
+                       else if (strcmp(value, "tsv") == 0)
+                               output_type = TSV;                      
+               }
+               else if (strcmp(key, "points") == 0)
+               {
+                       points_specified = true;
+                       if (strcmp(value, "all") == 0)
+                       {
+                               query_size = sensor->points_written;
+                       }
+                       else
                        {
-                               Log(LOGERR, "Operation already specified!");
+                               char * end;
+                               query_size = strtol(value, &end, 10);
+                               if (*end != '\0')
+                               {
+                                       Log(LOGERR, "Require \"all\" or an integer value: %s = %s", key, value);
+                                       status = STATUS_ERROR;
+                                       break;
+                               }
+                       }
+                       
+               }
+               else if (strcmp(key, "start_time") == 0)
+               {
+                       seek_time = true;
+                       char * end;
+                       start_time = strtod(value, &end);
+                       if (*end != '\0')
+                       {
+                               Log(LOGERR, "Require a double: %s = %s", key, value);
                                status = STATUS_ERROR;
                                break;
+                       }                       
+
+                       // Treat negative values as being relative to the current time
+                       if (start_time < 0)
+                       {
+                               start_time = current_time + start_time;
                        }
-                       operation = DUMP;
+                       start_time = floor(start_time);
+               }
+               else if (strcmp(key, "end_time") == 0)
+               {
+                       seek_time = true;
+                       char * end;
+                       end_time = strtod(value, &end);
+                       if (*end != '\0')
+                       {
+                               Log(LOGERR, "Require a double: %s = %s", key, value);
+                               status = STATUS_ERROR;
+                               break;
+                       }       
+
+                       // Treat negative values as being relative to the current time
+                       if (end_time < 0)
+                       {
+                               end_time = current_time + end_time;
+                       }               
+                       end_time = ceil(end_time);
+               }
+               // For backward compatability:
+               else if (strcmp(key, "dump") == 0)
+               {
+                       output_type = TSV;
+                       query_size = sensor->points_written+1;
                }
                else
                {
@@ -369,57 +521,67 @@ void Sensor_Handler(FCGIContext *context, char * params)
                FCGI_RejectJSON(context, "Invalid input parameters");
                return;
        }
-       
-       switch (operation)
+
+
+       if (seek_time)
        {
-               case DUMP:
+               if (end_time < 0 && !points_specified)
+                       end_index = sensor->points_written;
+               else
                {
-                       //Force download with content-disposition
-                       FCGI_PrintRaw("Content-type: text/plain\r\n"
-                               "Content-disposition: attachment;filename=%d.csv\r\n\r\n",
-                               sensor->id);
-                       //CRITICAL SECTION
-                       pthread_mutex_lock(&(sensor->mutex));
-                               fseek(sensor->file, 0, SEEK_SET);
-                               int amount_read = 0;
-                               do
-                               {
-                                       amount_read = fread(buffer, sizeof(DataPoint), SENSOR_QUERYBUFSIZ, sensor->file);
-                                       for (int i = 0; i < amount_read; ++i)
-                                       {
-                                               FCGI_PrintRaw("%f\t%f\n", buffer[i].time_stamp, buffer[i].value);
-                                       }
-
-                               }
-                               while (amount_read == SENSOR_QUERYBUFSIZ);
-                       pthread_mutex_unlock(&(sensor->mutex));
-                       // end critical section
-                       break;
+                       int count = 0; DataPoint d;
+                       end_index = FindTime(sensor, end_time, &count, &d);
+                       Log(LOGDEBUG, "FindTime - Looked for %f; found [%f,%f] after %d iterations; sensor %d, position %d", end_time, d.time_stamp, d.value, count, sensor->id, end_index);
                }
-               default:
+               if (start_time < 0)
+                       start_time = 0;
+               else
                {
-                       FCGI_BeginJSON(context, status);        
-                       FCGI_JSONPair(key, value); // should spit back sensor ID
-                       //Log(LOGDEBUG, "Call Sensor_Query...");
-                       int amount_read = Sensor_Query(sensor, buffer, SENSOR_QUERYBUFSIZ);
-                       //Log(LOGDEBUG, "Read %d DataPoints", amount_read);
-                       //Log(LOGDEBUG, "Produce JSON response");
+                       int count = 0; DataPoint d;
+                       start_index = FindTime(sensor, start_time, &count, &d);
+                       Log(LOGDEBUG, "FindTime - Looked for %f; found [%f,%f] after %d iterations; sensor %d, position %d", start_time, d.time_stamp, d.value, count, sensor->id, start_index);
+               }
+
+               if (points_specified)
+                       end_index = start_index + query_size;
+       }
+       else
+       {
+               start_index = sensor->points_written - query_size;
+               
+               end_index = sensor->points_written;
+       }
+       
+       if (start_index < 0)
+       {
+               Log(LOGNOTE, "start_index = %d => Clamped to 0", start_index);
+               start_index = 0;
+       }
+       if (end_index > sensor->points_written)
+       {
+               Log(LOGNOTE, "end_index = %d => Clamped to %d", end_index, sensor->points_written);
+               end_index = sensor->points_written;
+       }
+       
+       switch (output_type)
+       {
+               case JSON:
+                       FCGI_BeginJSON(context, status);
+                       FCGI_JSONLong("id", sensor->id);
                        FCGI_JSONKey("data");
-                       FCGI_JSONValue("[");
-                       for (int i = 0; i < amount_read; ++i)
-                       {
-                               //TODO: Consider; is it better to give both tv_sec and tv_usec to the client seperately, instead of combining here?
-                               
-                               FCGI_JSONValue("[%f, %f]", buffer[i].time_stamp, buffer[i].value);
-                               if (i+1 < amount_read)
-                                       FCGI_JSONValue(",");
-                       }
-                       FCGI_JSONValue("]");
-                       //Log(LOGDEBUG, "Done producing JSON response");
-                       FCGI_EndJSON(); 
+                       PrintData(sensor, start_index, end_index, output_type);
+                       FCGI_EndJSON();
+                       break;
+               default:
+                       FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
+                       PrintData(sensor, start_index, end_index, output_type);
+                       //Force download with content-disposition
+                       // Sam: This is cool, but I don't think we should do it
+                       //  - letting the user view it in the browser and then save with their own filename is more flexible
+                       //"Content-disposition: attachment;filename=%d.csv\r\n\r\n", sensor->id);
                        break;
-               }
        }
+       
 }
 
 /**

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