/**
* @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->read_file = NULL;
- df->write_file = NULL;
+ memset(df, 0, sizeof(DataFile));
+ pthread_mutex_init(&(df->mutex), NULL);
}
/**
// Set number of DataPoints
df->num_points = 0;
- // Set write FILE*
- df->write_file = fopen(filename, "w+");
- if (df->write_file == NULL)
- {
- Fatal("Error opening DataFile %s - %s", filename, strerror(errno));
- }
-
- // Set read FILE*
- df->read_file = df->write_file;
-
- //NOTE: Opening the same file in read mode gives funny results; fread generally reads less than expected
- // The strerror is: "Transport endpoint is not connected"
- /*
- fopen(filename, "r");
- if (df->read_file == NULL)
+ // Set file pointer
+ df->file = fopen(filename, "wb+");
+ if (df->file == NULL)
{
Fatal("Error opening DataFile %s - %s", filename, strerror(errno));
}
- */
-
}
/**
//TODO: Write data to TSV?
- // Clear the FILE*s
- df->read_file = NULL;
- df->write_file = NULL;
+ fclose(df->file);
- fclose(df->write_file);
+ // Clear the FILE*s
+ df->file = NULL;
// Clear the filename
free(df->filename);
*/
void Data_Save(DataFile * df, DataPoint * buffer, int amount)
{
- pthread_mutex_unlock(&(df->mutex));
+ pthread_mutex_lock(&(df->mutex));
assert(df != NULL);
assert(buffer != NULL);
assert(amount >= 0);
// Go to the end of the file
- if (fseek(df->write_file, 0, SEEK_END) < 0)
+ if (fseek(df->file, 0, SEEK_END) < 0)
{
Fatal("Error seeking to end of DataFile %s - %s", df->filename, strerror(errno));
}
// Attempt to write the DataPoints
- int amount_written = fwrite(buffer, sizeof(DataPoint), amount, df->write_file);
+ int amount_written = fwrite(buffer, sizeof(DataPoint), amount, df->file);
// Check if the correct number of points were written
if (amount_written != amount)
df->num_points += amount_written;
pthread_mutex_unlock(&(df->mutex));
-
}
/**
// If we would read past the end of the file, reduce the amount of points to read
- if (index + amount > df->num_points)
- {
- Log(LOGDEBUG, "Requested %d points but will only read %d to get to EOF (%d)", amount, df->num_points - index, df->num_points);
- amount = df->num_points - index;
- }
+ if (index + amount > df->num_points)
+ {
+ Log(LOGDEBUG, "Requested %d points but will only read %d to get to EOF (%d)", amount, df->num_points - index, df->num_points);
+ amount = df->num_points - index;
+ }
// Go to position in file
- if (fseek(df->read_file, index*sizeof(DataPoint), SEEK_SET))
+ if (fseek(df->file, index*sizeof(DataPoint), SEEK_SET))
{
Fatal("Error seeking to position %d in DataFile %s - %s", index, df->filename, strerror(errno));
}
// Attempt to read the DataPoints
- int amount_read = fread(buffer, sizeof(DataPoint), amount, df->read_file);
+ int amount_read = fread(buffer, sizeof(DataPoint), amount, df->file);
// Check if correct number of points were read
if (amount_read != amount)
* Print data points between two indexes using a given format
* @param df - DataFile to print
* @param start_index - Index to start at (inclusive)
- * @param end_index - Index to end at (inclusive)
+ * @param end_index - Index to end at (exclusive)
* @param format - The format to use
*/
void Data_PrintByIndexes(DataFile * df, int start_index, int end_index, DataFormat format)
assert(df != NULL);
assert(start_index >= 0);
assert(end_index >= 0);
- assert(end_index <= df->num_points-1 || df->num_points == 0);
+ assert(end_index <= df->num_points || df->num_points == 0);
const char * fmt_string; // Format for each data point
- char seperator; // Character used to seperate successive data points
+ char separator; // Character used to seperate successive data points
- // Determine what format string and seperator character to use
+ // Determine what format string and separator character to use
switch (format)
{
case JSON:
- fmt_string = "[%f,%f]";
- seperator = ',';
+ fmt_string = "[%.9f,%f]";
+ separator = ',';
// For JSON we need an opening bracket
FCGI_PrintRaw("[");
break;
case TSV:
- fmt_string = "%f\t%f";
- seperator = '\n';
+ fmt_string = "%.9f\t%f";
+ separator = '\n';
break;
}
- DataPoint buffer[DATA_BUFSIZ]; // Buffer
- // initialise buffer to stop stuff complaining
- memset(buffer, 0, sizeof(DataPoint)*DATA_BUFSIZ);
-
- if (start_index < end_index)
+ DataPoint buffer[DATA_BUFSIZ] = {{0}}; // Buffer
+ int index = start_index;
+
+ // Repeat until all DataPoints are printed
+ while (index < end_index)
{
+ // Fill the buffer from the DataFile
+ int amount_read = Data_Read(df, buffer, index, DATA_BUFSIZ);
- int index = start_index;
- // Repeat until all DataPoints are printed
- while (index <= end_index)
+ // Print all points in the buffer
+ for (int i = 0; i < amount_read && index < end_index; ++i)
{
- // Fill the buffer from the DataFile
- int amount_read = Data_Read(df, buffer, index, DATA_BUFSIZ);
-
- // Print all points in the buffer
- for (int i = 0; i < amount_read && index <= end_index; ++i)
- {
- // Print individual DataPoint
- FCGI_PrintRaw(fmt_string, buffer[i].time_stamp, buffer[i].value);
-
- // Last seperator is not required
- if (index+1 <= end_index)
- FCGI_PrintRaw("%c", seperator);
-
- // Advance the position in the DataFile
- ++index;
- }
+ // Print individual DataPoint
+ FCGI_PrintRaw(fmt_string, buffer[i].time_stamp, buffer[i].value);
+
+ // Last separator is not required
+ if (index+1 < end_index)
+ FCGI_PrintRaw("%c", separator);
+
+ // Advance the position in the DataFile
+ ++index;
}
}
* Prints nothing if the time stamp
* @param df - DataFile to print
* @param start_time - Time to start from (inclusive)
- * @param end_time - Time to end at (inclusive)
+ * @param end_time - Time to end at (exclusive)
* @param format - The format to use
*/
void Data_PrintByTimes(DataFile * df, double start_time, double end_time, DataFormat format)
{
assert(df != NULL);
- assert(start_time >= 0);
- assert(end_time >= 0);
- assert(end_time >= start_time);
-
- DataPoint closest;
-
- // Get starting index
- int start_index = Data_FindByTime(df, start_time, &closest);
-
- // Start time is greater than most recent time stamp
- if (start_index >= df->num_points-1)
+ //Clamp boundaries
+ if (start_time < 0)
+ start_time = 0;
+ if (end_time < 0)
+ end_time = 0;
+
+ int start_index = 0, end_index = 0;
+ if (start_time < end_time)
{
- if (start_index == 0 || closest.time_stamp < start_time)
- {
- Data_PrintByIndexes(df, 0, 0, format); // Will print "empty" dataset
- return;
- }
+ start_index = Data_FindByTime(df, start_time, NULL);
+ end_index = Data_FindByTime(df, end_time, NULL);
}
- // Get finishing index
- int end_index = Data_FindByTime(df, end_time, &closest);
-
- // Print data between the indexes
Data_PrintByIndexes(df, start_index, end_index, format);
}
{
assert(df != NULL);
assert(time_stamp >= 0);
- assert(closest != NULL);
+ //assert(closest != NULL);
DataPoint tmp; // Current DataPoint in binary search
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]);
+}