X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;ds=sidebyside;f=server%2Fsensor.c;h=622251054fb52dfedf04984cd20761f6b81d8c5c;hb=496c40213e1cd6eee6cee3f1cabc307c2c893893;hp=a3d3f0b4a0c0e75f0f5de2c5d0c84db15cb11b68;hpb=0b95dfaf594f4e6866ff8e18040c62382cad7d08;p=matches%2FMCTX3420.git

diff --git a/server/sensor.c b/server/sensor.c
index a3d3f0b..6222510 100644
--- a/server/sensor.c
+++ b/server/sensor.c
@@ -5,9 +5,8 @@
  */
 
 
-
+#include "common.h"
 #include "sensor.h"
-#include "log.h"
 #include <math.h>
 
 /**
@@ -48,8 +47,8 @@ DataPoint GetData(int sensor_id)
  */
 void Destroy(Sensor * s)
 {
-	//TODO: Surely we'll need to do something here?
 	// Maybe move the binary file into long term file storage?
+	fclose(s->file);
 }
 
 
@@ -64,14 +63,21 @@ void Sensor_Init(Sensor * s, int id)
 	s->read_offset = 0;
 	s->id = id;
 
-	if (s->id >= pow(10, FILENAMESIZE))
+	#define FILENAMESIZE BUFSIZ
+	char filename[FILENAMESIZE];
+	//if (s->id >= pow(10, FILENAMESIZE))
+	if (false)
 	{
 		Fatal("Too many sensors! FILENAMESIZE is %d; increase it and recompile.", FILENAMESIZE);
 	}
-	sprintf(s->filename, "%d", s->id);
-	unlink(s->filename); //TODO: Move old files somewhere
 
-	Log(LOGDEBUG, "Initialised sensor %d; binary file is \"%s\"", id, s->filename);
+	pthread_mutex_init(&(s->mutex), NULL);
+		
+	sprintf(filename, "%d", s->id);
+	unlink(filename); //TODO: Move old files somewhere
+
+	s->file = fopen(filename, "a+b"); // open binary file
+	Log(LOGDEBUG, "Initialised sensor %d; binary file is \"%s\"", id, filename);
 }
 
 
@@ -104,23 +110,13 @@ 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));
-
-			// Open binary file in append mode and dump buffer into it
-			FILE * file = fopen(s->filename, "ab");
-			if (file == NULL)
-			{
-				Fatal("Couldn't open file \"%s\" mode ab - %s", s->filename, strerror(errno));
-			}
-			int amount_written = fwrite(s->buffer, sizeof(DataPoint), SENSOR_DATABUFSIZ, file);
+			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);
-
-			fclose(file);
-
+			//Log(LOGDEBUG, "Wrote %d data points for sensor %d", amount_written, s->id);
 		pthread_mutex_unlock(&(s->mutex));
 		// End of critical section
 
@@ -130,4 +126,107 @@ void * Sensor_Main(void * arg)
 	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;
+}
+
+/**
+ * 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;
+	const char * key; const char * value;
+
+	int sensor_id = SENSOR_NONE;
+
+	while ((params = FCGI_KeyPair(params, &key, &value)) != NULL)
+	{
+		Log(LOGDEBUG, "Got key=%s and value=%s", key, value);
+		if (strcmp(key, "id") == 0)
+		{
+			char *end;
+			if (sensor_id != SENSOR_NONE)
+			{
+				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;
+			}
+			//TODO: Use human readable sensor identifier string for API?
+			sensor_id = strtol(value, &end, 10);
+			if (*end != '\0')
+			{
+				Log(LOGERR, "Sensor id not an integer; %s", value);
+				status = STATUS_ERROR;
+				break;
+			}
+		}
+		else
+		{
+			Log(LOGERR, "Unknown key \"%s\" (value = %s)", key, value);
+			status = STATUS_ERROR;
+			break;
+		}		
+	}
+
+	if (sensor_id == SENSOR_NONE)
+	{
+		Log(LOGERR, "No sensor id specified");
+		status = STATUS_ERROR;
+	}
+	else if (sensor_id >= NUMSENSORS || sensor_id < 0)
+	{
+		Log(LOGERR, "Invalid sensor id %d", sensor_id);
+		status = STATUS_ERROR;
+	}
 
+	if (status == STATUS_ERROR)
+	{
+		FCGI_RejectJSON(context);
+	}
+	else
+	{
+		FCGI_BeginJSON(context, status);	
+		FCGI_JSONPair(key, value); // should spit back sensor ID
+		//Log(LOGDEBUG, "Call Sensor_Query...");
+		int amount_read = Sensor_Query(&(g_sensors[sensor_id]), 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)
+		{
+			FCGI_JSONValue("[%f, %f]", buffer[i].time, buffer[i].value);
+			if (i+1 < amount_read)
+				FCGI_JSONValue(",");
+		}
+		FCGI_JSONValue("]");
+		//Log(LOGDEBUG, "Done producing JSON response");
+		FCGI_EndJSON();	
+	}
+}