--- a/file-data-provider.c	Thu Mar 21 19:00:22 2013 +0100
+++ b/file-data-provider.c	Fri Mar 22 18:49:58 2013 +0100
@@ -1,5 +1,6 @@
 /* FXAnalise data provider reading data from KK data file on disc */
 
+#include <userint.h>
 #include <ansi_c.h>
 #include <utility.h>
 #include <formatio.h>
@@ -11,111 +12,110 @@
 extern int acquiring;
 /* data queue */
 extern CmtTSQHandle dataQueue;
+/* callback receiving messages in the main thread */
+void CVICALLBACK MessageCB (void *callbackData);
+/* message */
+static char message[1024];
 
-void CurrentFileName(char *fname)
-{
-	char day[3], month[3], year[3];
-	char *date = DateStr();
-	Scan(date, "%s>%s[w2]-%s[w2]-20%s[w2]", month, day, year);
-	Fmt(fname, "%s<%s\\%s%s%s_Frequ.txt", LOGFILEPATH, year, month, day);
-}
+#define SendMessage(threadId, ...)                                \
+	do { 												          \
+		snprintf(message, sizeof(message) - 1, ##__VA_ARGS__);    \
+		PostDeferredCallToThread(MessageCB, message, threadId);   \
+	} while (0)
 
-#define FXLINELENGTH 123 
 
 int CVICALLBACK FileDataProvider (void *functionData)
 {
 	int mainThreadId;
+	char dataFileName[MAX_PATHNAME_LEN];
+	int fd;
+	int read;
+	int year, month, day, hour, min, sec, msec;
+	struct tm t;
+	char line[1024];
+	double data[5];
+	double now;
 	
 	/* get main thread id to post messages to it */
 	mainThreadId = CmtGetMainThreadID();
 	
-	int LogFile;
-	long LogFileSize;
-	char LogFileName[MAX_PATHNAME_LEN];
-	long OldLogFilePtr = 0;
-	char LineBuffer[FXLINELENGTH + 10];
+	/* guess current data log file name */
+	GetCurrentDateTime(&now);
+	GetDateTimeElements(now, NULL, NULL, NULL, &month, &day, &year);
+	snprintf(dataFileName, sizeof(dataFileName) - 1, 
+		"%s\\%02d%02d%02d_Frequ.txt", LOGFILEPATH, year % 100, month, day);
 	
-	char TimeTag[] = "100103 000000.000";   // K+K time tag meaning here 2010 january the 3rd at 00:00:00.000
-	char Year[] = "2010";
-	char Month[] = "01";
-	char Day[] = "03";
-	char Hour[] = "00";
-	char Min[] = "00" ;
-	char Sec[] = "00.000";
-	struct tm LocalTime ;
-	time_t utcTime;
+	/* open file */
+	fd = OpenFile(dataFileName, VAL_READ_ONLY, VAL_OPEN_AS_IS, VAL_ASCII);
+	if (fd < 0) {
+		/* notify error to the main thread */
+		SendMessage(mainThreadId, "error opening data file '%s'", dataFileName);
+	}
 	
-	double data[5];
-	
-	CurrentFileName(LogFileName);
-	GetFileInfo(LogFileName, &OldLogFilePtr);
-	OldLogFilePtr -= OldLogFilePtr%FXLINELENGTH + FXLINELENGTH - 2;
+	/* seek to file end */
+	SetFilePtr(fd, 0, 2);
 	
 	while (acquiring) {
-			
-		GetFileInfo(LogFileName, &LogFileSize);
-		if (LogFileSize > OldLogFilePtr+2*FXLINELENGTH-2) {  // if a complete newline has been written
-						
-			// Open Log file and get to the beginning of newly completed line
-			LogFile = OpenFile(LogFileName, VAL_READ_ONLY, VAL_OPEN_AS_IS, VAL_ASCII);
-			OldLogFilePtr += FXLINELENGTH;
-			SetFilePtr(LogFile, OldLogFilePtr, 0);
-				
-			// return the last complete string from the log file and scan it for date and time information 
-				
-			// first, the time tag, and store it in various formats
-			ReadFile(LogFile, TimeTag, 17);
-				
-			CopyBytes(Year,2,TimeTag,0,2); // first 2 bytes of year string remains "20"
-			CopyBytes(Month,0,TimeTag,2,2);
-			CopyBytes(Day,0,TimeTag,4,2);
-			CopyBytes(Hour,0,TimeTag,7,2);
-			CopyBytes(Min,0,TimeTag,9,2);
-			CopyBytes(Sec,0,TimeTag,11,6);
-			
-			Fmt(&LocalTime.tm_year, "%d<%s", Year);
-			Fmt(&LocalTime.tm_mon,  "%d<%s", Month);
-			Fmt(&LocalTime.tm_mday, "%d<%s", Day);
-			Fmt(&LocalTime.tm_hour, "%d<%s", Hour);
-			Fmt(&LocalTime.tm_min,  "%d<%s", Min);
-			Fmt(&LocalTime.tm_sec,  "%d<%s", "00");    // special case to handle non integer number of UTC seconds
+
+		/* read one line from data file */
+		read = ReadLine(fd, line, sizeof(line) - 1);
+		if (read < 1) {
+			Delay(0.05);
+			continue;
+		}
+		
+		/* parse data */
+		read = Scan(line, "%d[w2]%d[w2]%d[w2] %d[w2]%d[w2]%d[w2].%d %f %f %f %f", 
+			&year, &month, &day, &hour, &min, &sec, &msec, &data[1], &data[2], &data[3], &data[4]);
+		if (read != 11) {
+			/* notify error to the main thread */
+			SendMessage(mainThreadId, "error parsing data log line");
+			/* skip line */
+			continue;
+		}
+		
+		t.tm_hour = hour;
+		t.tm_min = min;
+		t.tm_sec = sec;
+		t.tm_mday = day;
+		/* correct month count */
+		t.tm_mon = month - 1;
+		/* years since 1900 */
+		t.tm_year = year + 2000 - 1900;
+		/* daylight saving must be set to -1 */
+		t.tm_isdst = -1;
 			
-			LocalTime.tm_hour += 0;
-			LocalTime.tm_min  -= 0;  
-			LocalTime.tm_sec  -= 0;  
-			LocalTime.tm_mon  -= 1;  	// january is month 0 for tm struct
-			LocalTime.tm_year -= 1900; // year is number of years since 1900 for tm struct
-			LocalTime.tm_isdst = -1;  // daylight saving flag MUST be set to -1 (unallocated is bugging and +1 is making 1 hour error in summer)
+		/* convert into seconds since 1 January 1900 00:00:00 and add milliseconds */
+		data[0] = mktime(&t) + 1e-3 * msec;
+				
+		/* convert from kHz to Hz */
+		data[1] = data[1] * 1000.0;
+		data[2] = data[2] * 1000.0;
+		data[3] = data[3] * 1000.0;
+		data[4] = data[4] * 1000.0;
 			
-			utcTime = mktime (&LocalTime);
-			data[0] = (double) utcTime + strtod(Sec,NULL);
-			
-			// scan the line for counters's channels information
-				
-			ReadLine(LogFile, LineBuffer, FXLINELENGTH+9);
-			CloseFile(LogFile);
-				
-			Scan(LineBuffer, "%f%f%f%f", &data[1], &data[2], &data[3], &data[4]);
+		/* push data into the data queue */
+		CmtWriteTSQData(dataQueue, data, 5, TSQ_INFINITE_TIMEOUT, 0);
 			
-			/* convert from kHz to Hz */
-			data[1] = data[1] * 1000.0;
-			data[2] = data[2] * 1000.0;
-			data[3] = data[3] * 1000.0;
-			data[4] = data[4] * 1000.0;
-			
-			/* push data into the data queue */
-			CmtWriteTSQData(dataQueue, data, 5, TSQ_INFINITE_TIMEOUT, 0);
-			
-			// Special case to handle change of day at next second
-			if ( LocalTime.tm_hour==23 && LocalTime.tm_min==59 && strtod(Sec,NULL)>=58 ) {
-				do {
-					Delay(5.1);
-					CurrentFileName(LogFileName);
-				} while (!GetFileInfo(LogFileName, &OldLogFilePtr));
-				OldLogFilePtr = 2;
+		/* handle switch to next data file */
+		if ((hour == 23) && (min == 59) && (sec == 59)) {
+				
+			/* next data file name */
+			snprintf(dataFileName, sizeof(dataFileName) - 1, 
+				"%s\\%02d%02d%02d_Frequ.txt", LOGFILEPATH, year, month, day + 1);
+				
+			/* close data file */
+			CloseFile(fd);
+				
+			/* wait for new data file to appear */
+			int retry = 0;
+			while (retry--) {
+				fd = OpenFile(dataFileName, VAL_READ_ONLY, VAL_OPEN_AS_IS, VAL_ASCII);
+				if (fd != -1)
+					break;
+				Delay(0.01);
 			}
 		}
-		Delay(0.05);
 	}
 	return 0;
 }