/**
* @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"
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);
}
/**
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;
}
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 format - 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]);
+}