X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;ds=sidebyside;f=server%2Fsensor.c;h=8115a3b3de6232f6bde043a1100c4633ee480a86;hb=459042e32b6ffb31338e3f5a88ddb401530d1beb;hp=b7461343998c28f028d8cedeaa6bfe297e4849b7;hpb=97d3625dcb84e6371d2464c93ae9bef8a3d4b466;p=matches%2FMCTX3420.git

diff --git a/server/sensor.c b/server/sensor.c
index b746134..8115a3b 100644
--- a/server/sensor.c
+++ b/server/sensor.c
@@ -5,39 +5,64 @@
  */
 
 
-
+#include "common.h"
 #include "sensor.h"
-#include "log.h"
+#include "options.h"
 #include <math.h>
 
+/** Array of sensors, initialised by Sensor_Init **/
+static Sensor g_sensors[NUMSENSORS]; //global to this file
+static const char * g_sensor_names[] = {"analog_test0","analog_test1","digital_test0"};
 /**
  * Read a data value from a sensor; block until value is read
  * @param sensor_id - The ID of the sensor
- * @returns The current value of the sensor
+ * @param d - DataPoint to set
+ * @returns NULL for digital sensors when data is unchanged, otherwise d
  */
-DataPoint GetData(int sensor_id)
+DataPoint * GetData(int sensor_id, DataPoint * d)
 {
 	// switch based on the sensor_id at the moment for testing;
 	// might be able to just directly access ADC from sensor_id?
 	//TODO: Implement for real sensors
 
-	DataPoint d;
-	//TODO: Deal with time stamps properly
-	static int count = 0;
-	d.time = count++;
+	
+	//TODO: We should ensure the time is *never* allowed to change on the server if we use gettimeofday
+	//		Another way people might think of getting the time is to count CPU cycles with clock()
+	//		But this will not work because a) CPU clock speed may change on some devices (RPi?) and b) It counts cycles used by all threads
+	
+	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);
+
+	// Make time relative
+	//d->time_stamp.tv_sec -= g_options.start_time.tv_sec;
+	//d->time_stamp.tv_usec -= g_options.start_time.tv_usec;
+	
 	switch (sensor_id)
 	{
-		case SENSOR_TEST0:
-			d.value = count;
+		case ANALOG_TEST0:
+		{
+			static int count = 0;
+			d->value = count++;
+			break;
+		}
+		case ANALOG_TEST1:
+			d->value = (double)(rand() % 100) / 100;
+			break;
+	
+		//TODO: For digital sensors, consider only updating when sensor is actually changed
+		case DIGITAL_TEST0:
+			d->value = t.tv_sec % 2;
 			break;
-		case SENSOR_TEST1:
-			d.value = (float)(rand() % 100) / 100;
+		case DIGITAL_TEST1:
+			d->value = (t.tv_sec+1)%2;
 			break;
 		default:
 			Fatal("Unknown sensor id: %d", sensor_id);
 			break;
 	}	
 	usleep(100000); // simulate delay in sensor polling
+
 	return d;
 }
 
@@ -58,18 +83,19 @@ void Destroy(Sensor * s)
  * Initialise a sensor
  * @param s - Sensor to initialise
  */
-void Sensor_Init(Sensor * s, int id)
+void Init(Sensor * s, int id)
 {
 	s->write_index = 0;
-	s->read_offset = 0;
 	s->id = id;
 
-	#define FILENAMESIZE 4
+	#define FILENAMESIZE 3
 	char filename[FILENAMESIZE];
 	if (s->id >= pow(10, FILENAMESIZE))
 	{
 		Fatal("Too many sensors! FILENAMESIZE is %d; increase it and recompile.", FILENAMESIZE);
 	}
+
+	pthread_mutex_init(&(s->mutex), NULL);
 		
 	sprintf(filename, "%d", s->id);
 	unlink(filename); //TODO: Move old files somewhere
@@ -79,6 +105,9 @@ void Sensor_Init(Sensor * s, int id)
 }
 
 
+
+
+
 /**
  * Run the main sensor polling loop
  * @param arg - Cast to Sensor* - Sensor that the thread will handle
@@ -88,7 +117,7 @@ void * Sensor_Main(void * arg)
 {
 	Sensor * s = (Sensor*)(arg);
 
-	while (true) //TODO: Exit condition
+	while (Thread_Runstate() == RUNNING) //TODO: Exit condition
 	{
 		// The sensor will write data to a buffer until it is full
 		// Then it will open a file and dump the buffer to the end of it.
@@ -100,7 +129,11 @@ void * Sensor_Main(void * arg)
 
 		while (s->write_index < SENSOR_DATABUFSIZ)
 		{
-			s->buffer[s->write_index] = GetData(s->id);
+			DataPoint * d = &(s->buffer[s->write_index]);
+			if (GetData(s->id, d) == NULL)
+			{
+				Fatal("Error collecting data");
+			}
 			s->write_index += 1;
 		}
 
@@ -108,20 +141,214 @@ void * Sensor_Main(void * arg)
 
 		// CRITICAL SECTION (no threads should be able to read/write the file at the same time)
 		pthread_mutex_lock(&(s->mutex));
+			//TODO: Valgrind complains about this fseek: "Syscall param write(buf) points to uninitialised byte(s)"
+			//		Not sure why, but we should find out and fix it.
 			fseek(s->file, 0, SEEK_END);
 			int amount_written = fwrite(s->buffer, sizeof(DataPoint), SENSOR_DATABUFSIZ, s->file);
 			if (amount_written != SENSOR_DATABUFSIZ)
 			{
 				Fatal("Wrote %d data points and expected to write %d to \"%s\" - %s", amount_written, SENSOR_DATABUFSIZ, strerror(errno));
 			}
-			Log(LOGDEBUG, "Wrote %d data points for sensor %d", amount_written, s->id);
+			//Log(LOGDEBUG, "Wrote %d data points for sensor %d", amount_written, s->id);
 		pthread_mutex_unlock(&(s->mutex));
 		// End of critical section
 
 		s->write_index = 0; // reset position in buffer
 		
 	}
-	return NULL;
+	Log(LOGDEBUG, "Thread for sensor %d exits", s->id);
+	return NULL; 
 }
 
+/**
+ * Fill buffer with most recent sensor data
+ * @param s - Sensor to use
+ * @param buffer - Buffer to fill
+ * @param bufsiz - Size of buffer to fill
+ * @returns The number of DataPoints actually read
+ */
+int Sensor_Query(Sensor * s, DataPoint * buffer, int bufsiz)
+{
+	int amount_read = 0;
+	//CRITICAL SECTION (Don't access file while sensor thread is writing to it!)
+	pthread_mutex_lock(&(s->mutex));
+		
+		fseek(s->file, -bufsiz*sizeof(DataPoint), SEEK_END);
+		amount_read = fread(buffer, sizeof(DataPoint), bufsiz, s->file);
+		//Log(LOGDEBUG, "Read %d data points", amount_read);		
+	pthread_mutex_unlock(&(s->mutex));
+	return amount_read;
+}
 
+/**
+ * Get a Sensor given an ID string
+ * @param id_str ID string
+ * @returns Sensor* identified by the string; NULL on error
+ */
+Sensor * Sensor_Identify(const char * id_str)
+{
+	char * end;
+	// Parse string as integer
+	int id = strtol(id_str, &end, 10);
+	if (*end != '\0')
+	{
+		return NULL;
+	}
+	// Bounds check
+	if (id < 0 || id > NUMSENSORS)
+		return NULL;
+
+
+	Log(LOGDEBUG, "Sensor \"%s\" identified", g_sensor_names[id]);
+	return g_sensors+id;
+}
+
+/**
+ * Handle a request to the sensor module
+ * @param context - The context to work in
+ * @param params - Parameters passed
+ */
+void Sensor_Handler(FCGIContext *context, char * params)
+{
+	DataPoint buffer[SENSOR_QUERYBUFSIZ];
+	StatusCodes status = STATUS_OK;
+
+	enum {DEFAULT, DUMP} operation = DEFAULT;
+
+	const char * key; const char * value;
+
+	Sensor * sensor = NULL;
+
+	while ((params = FCGI_KeyPair(params, &key, &value)) != NULL)
+	{
+		Log(LOGDEBUG, "Got key=%s and value=%s", key, value);
+		if (strcmp(key, "id") == 0)
+		{
+			if (sensor != NULL)
+			{
+				Log(LOGERR, "Only one sensor id should be specified");
+				status = STATUS_ERROR;
+				break;
+			}
+			if (*value == '\0')
+			{
+				Log(LOGERR, "No id specified.");
+				status = STATUS_ERROR;
+				break;
+			}
+
+			sensor = Sensor_Identify(value);
+			if (sensor == NULL)
+			{
+				Log(LOGERR, "Invalid sensor id: %s", value);
+				status = STATUS_ERROR;
+				break;
+			}
+		}
+		else if (strcmp(key, "dump") == 0)
+		{
+			if (operation != DEFAULT)
+			{
+				Log(LOGERR, "Operation already specified!");
+				status = STATUS_ERROR;
+				break;
+			}
+			operation = DUMP;
+		}
+		else
+		{
+			Log(LOGERR, "Unknown key \"%s\" (value = %s)", key, value);
+			status = STATUS_ERROR;
+			break;
+		}		
+	}
+
+	if (status != STATUS_ERROR && sensor == NULL)
+	{
+		Log(LOGERR, "No valid sensor id given");
+		status = STATUS_ERROR;
+	}
+
+	if (status == STATUS_ERROR)
+	{
+		FCGI_RejectJSON(context);
+		return;
+	}
+	
+	switch (operation)
+	{
+		case DUMP:
+		{
+			FCGI_PrintRaw("Content-type: text/plain\r\n\r\n");
+			//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;
+		}
+		default:
+		{
+			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");
+			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();	
+			break;
+		}
+	}
+}
+
+/**
+ * Setup Sensors, start Sensor polling thread(s)
+ */
+void Sensor_Spawn()
+{
+	// start sensor threads
+	for (int i = 0; i < NUMSENSORS; ++i)
+	{
+		Init(g_sensors+i, i);
+		pthread_create(&(g_sensors[i].thread), NULL, Sensor_Main, (void*)(g_sensors+i));
+	}
+}
+
+/**
+ * Quit Sensor loops
+ */
+void Sensor_Join()
+{
+	if (!Thread_Runstate())
+	{
+		Fatal("This function should not be called before Thread_QuitProgram");
+	}
+	for (int i = 0; i < NUMSENSORS; ++i)
+	{
+		pthread_join(g_sensors[i].thread, NULL);
+		Destroy(g_sensors+i);
+	}
+}