X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=server%2Fsensor.c;h=ab687afdf5ecee1c75293888ad592fcdca0925a7;hb=82a411cede82ee10a9d29dc08ca01949576ede24;hp=a3d3f0b4a0c0e75f0f5de2c5d0c84db15cb11b68;hpb=72077d49c8dcf079d52a266717a8bda9db9db0ab;p=matches%2FMCTX3420.git

diff --git a/server/sensor.c b/server/sensor.c
index a3d3f0b..ab687af 100644
--- a/server/sensor.c
+++ b/server/sensor.c
@@ -48,8 +48,8 @@ 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 +64,21 @@ 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 +111,13 @@ 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 +127,24 @@ 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;
+}
+