Add usleep to strain.c just in case...

[matches/MCTX3420.git] / server / data.c

diff --git a/server/data.c b/server/data.c
index c4d7b58..19828bc 100644 (file)
--- a/server/data.c
+++ b/server/data.c
@@ -1,6 +1,6 @@
 /**
  * @file data.c
- * @purpose Implementation of data handling functions; saving, loading, displaying, selecting.
+ * @brief Implementation of data handling functions; saving, loading, displaying, selecting.
  */
 
 #include "data.h"
@@ -13,8 +13,8 @@
 void Data_Init(DataFile * df)
 {
        // Everything is NULL
-       df->filename = NULL;
-       df->file = NULL;
+       memset(df, 0, sizeof(DataFile));
+       pthread_mutex_init(&(df->mutex), NULL);
 }
 
 /**
@@ -161,13 +161,13 @@ void Data_PrintByIndexes(DataFile * df, int start_index, int end_index, DataForm
        switch (format)
        {
                case JSON:
-                       fmt_string = "[%f,%f]";
+                       fmt_string = "[%.9f,%f]";
                        separator = ',';
                        // For JSON we need an opening bracket
                        FCGI_PrintRaw("["); 
                        break;
                case TSV:
-                       fmt_string = "%f\t%f";
+                       fmt_string = "%.9f\t%f";
                        separator = '\n';
                        break;
        }
@@ -285,3 +285,122 @@ int Data_FindByTime(DataFile * df, double time_stamp, DataPoint * closest)
        return index;
        
 }
+
+/**
+ * Helper; handle FCGI response that requires data
+ * Should be called first.
+ * @param df - DataFile to access
+ * @param start - Info about start_time param 
+ * @param end - Info about end_time param
+ * @param fmt - Info about format param
+ * @param current_time - Current time
+ */
+void Data_Handler(DataFile * df, FCGIValue * start, FCGIValue * end, DataFormat format, double current_time)
+{
+       double start_time = *(double*)(start->value);
+       double end_time = *(double*)(end->value);
+
+       if (format == JSON)
+       {
+               FCGI_JSONKey("data");
+       }
+
+       // If a time was specified
+       if (FCGI_RECEIVED(start->flags) || FCGI_RECEIVED(end->flags))
+       {
+               // Wrap times relative to the current time
+               if (start_time < 0)
+                       start_time += current_time;
+               if (end_time < 0)
+                       end_time += current_time;
+
+               // Print points by time range
+               Data_PrintByTimes(df, start_time, end_time, format);
+
+       }
+       else // No time was specified; just return a recent set of points
+       {
+               pthread_mutex_lock(&(df->mutex));
+                       int start_index = df->num_points-DATA_BUFSIZ;
+                       int end_index = df->num_points-1;
+               pthread_mutex_unlock(&(df->mutex));
+
+               // Bounds check
+               if (start_index < 0)
+                       start_index = 0;
+               if (end_index < 0)
+                       end_index = 0;
+
+               // Print points by indexes
+               Data_PrintByIndexes(df, start_index, end_index, format);
+       }
+
+}
+
+/**
+ * Helper - Convert human readable format string to DataFormat
+ * @param fmt - FCGIValue to use
+ */
+DataFormat Data_GetFormat(FCGIValue * fmt)
+{
+       const char * fmt_str = *(const char**)(fmt->value);
+       // Check if format type was specified
+       if (FCGI_RECEIVED(fmt->flags))
+       {
+               if (strcmp(fmt_str, "json") == 0)
+                       return JSON;
+               else if (strcmp(fmt_str, "tsv") == 0)
+                       return TSV;
+               else
+                       Log(LOGERR, "Unknown format type \"%s\"", fmt_str);
+       }
+       return JSON;
+}
+
+/**
+ * Binary search for index of a double in an array
+ * @param value - The value
+ * @param x - The array
+ * @param size - Sizeof the array
+ */
+int FindClosest(double value, double x[], int size)
+{
+       int upper = size-1;
+       int lower = 0;
+       int index = 0;
+       while (upper - lower > 1)
+       {
+               index = lower + ((upper - lower)/2);
+               double look = x[index];
+               if (look > value)
+                       upper = index;
+               else if (look < value)
+                       lower = index;
+               else
+                       return index;
+       }
+
+       if (x[index] > value && index > 0)
+               --index;
+       return index;
+
+}
+
+/**
+ * Get calibrated value by interpolation in array y
+ * @param value - Raw measured value
+ * @param x - x values (raw values) of the data
+ * @param y - calibrated values
+ * @param size - Number of values in the arrays
+ * @returns interpolated calibrated value
+ */
+double Data_Calibrate(double value, double x[], double y[], int size)
+{
+       int i = FindClosest(value, x, size);
+       if (i >= size-1)
+       {
+               i = size-2;     
+       }
+       double dist = (value - x[i])/(x[i+1] - x[i]);
+       return y[i] + dist*(y[i+1]-y[i]);
+}