Files
grafana-zabbix/dist/datasource-zabbix/timeseries.js
2017-07-28 12:42:49 +03:00

485 lines
13 KiB
JavaScript

'use strict';
System.register(['lodash', './utils'], function (_export, _context) {
"use strict";
var _, utils, POINT_VALUE, POINT_TIMESTAMP, exportedFunctions;
/**
* Downsample time series by using given function (avg, min, max).
*/
function downsample(datapoints, time_to, ms_interval, func) {
var downsampledSeries = [];
var timeWindow = {
from: time_to * 1000 - ms_interval,
to: time_to * 1000
};
var points_sum = 0;
var points_num = 0;
var value_avg = 0;
var frame = [];
for (var i = datapoints.length - 1; i >= 0; i -= 1) {
if (timeWindow.from < datapoints[i][1] && datapoints[i][1] <= timeWindow.to) {
points_sum += datapoints[i][0];
points_num++;
frame.push(datapoints[i][0]);
} else {
value_avg = points_num ? points_sum / points_num : 0;
if (func === "max") {
downsampledSeries.push([_.max(frame), timeWindow.to]);
} else if (func === "min") {
downsampledSeries.push([_.min(frame), timeWindow.to]);
}
// avg by default
else {
downsampledSeries.push([value_avg, timeWindow.to]);
}
// Shift time window
timeWindow.to = timeWindow.from;
timeWindow.from -= ms_interval;
points_sum = 0;
points_num = 0;
frame = [];
// Process point again
i++;
}
}
return downsampledSeries.reverse();
}
/**
* Group points by given time interval
* datapoints: [[<value>, <unixtime>], ...]
*/
function groupBy(datapoints, interval, groupByCallback) {
var ms_interval = utils.parseInterval(interval);
// Calculate frame timestamps
var frames = _.groupBy(datapoints, function (point) {
// Calculate time for group of points
return Math.floor(point[1] / ms_interval) * ms_interval;
});
// frame: { '<unixtime>': [[<value>, <unixtime>], ...] }
// return [{ '<unixtime>': <value> }, { '<unixtime>': <value> }, ...]
var grouped = _.mapValues(frames, function (frame) {
var points = _.map(frame, function (point) {
return point[0];
});
return groupByCallback(points);
});
// Convert points to Grafana format
return sortByTime(_.map(grouped, function (value, timestamp) {
return [Number(value), Number(timestamp)];
}));
}
function groupBy_perf(datapoints, interval, groupByCallback) {
if (datapoints.length === 0) {
return [];
}
var ms_interval = utils.parseInterval(interval);
var grouped_series = [];
var frame_values = [];
var frame_value = void 0;
var frame_ts = datapoints.length ? getPointTimeFrame(datapoints[0][POINT_TIMESTAMP], ms_interval) : 0;
var point_frame_ts = frame_ts;
var point = void 0;
for (var i = 0; i < datapoints.length; i++) {
point = datapoints[i];
point_frame_ts = getPointTimeFrame(point[POINT_TIMESTAMP], ms_interval);
if (point_frame_ts === frame_ts) {
frame_values.push(point[POINT_VALUE]);
} else if (point_frame_ts > frame_ts) {
frame_value = groupByCallback(frame_values);
grouped_series.push([frame_value, frame_ts]);
// Move frame window to next non-empty interval and fill empty by null
frame_ts += ms_interval;
while (frame_ts < point_frame_ts) {
grouped_series.push([null, frame_ts]);
frame_ts += ms_interval;
}
frame_values = [point[POINT_VALUE]];
}
}
frame_value = groupByCallback(frame_values);
grouped_series.push([frame_value, frame_ts]);
return grouped_series;
}
/**
* Summarize set of time series into one.
* @param {datapoints[]} timeseries array of time series
*/
function sumSeries(timeseries) {
// Calculate new points for interpolation
var new_timestamps = _.uniq(_.map(_.flatten(timeseries, true), function (point) {
return point[1];
}));
new_timestamps = _.sortBy(new_timestamps);
var interpolated_timeseries = _.map(timeseries, function (series) {
series = fillZeroes(series, new_timestamps);
var timestamps = _.map(series, function (point) {
return point[1];
});
var new_points = _.map(_.difference(new_timestamps, timestamps), function (timestamp) {
return [null, timestamp];
});
var new_series = series.concat(new_points);
return sortByTime(new_series);
});
_.each(interpolated_timeseries, interpolateSeries);
var new_timeseries = [];
var sum;
for (var i = new_timestamps.length - 1; i >= 0; i--) {
sum = 0;
for (var j = interpolated_timeseries.length - 1; j >= 0; j--) {
sum += interpolated_timeseries[j][i][0];
}
new_timeseries.push([sum, new_timestamps[i]]);
}
return sortByTime(new_timeseries);
}
function scale(datapoints, factor) {
return _.map(datapoints, function (point) {
return [point[0] * factor, point[1]];
});
}
function scale_perf(datapoints, factor) {
for (var i = 0; i < datapoints.length; i++) {
datapoints[i] = [datapoints[i][POINT_VALUE] * factor, datapoints[i][POINT_TIMESTAMP]];
}
return datapoints;
}
/**
* Simple delta. Calculate value delta between points.
* @param {*} datapoints
*/
function delta(datapoints) {
var newSeries = [];
var deltaValue = void 0;
for (var i = 1; i < datapoints.length; i++) {
deltaValue = datapoints[i][0] - datapoints[i - 1][0];
newSeries.push([deltaValue, datapoints[i][1]]);
}
return newSeries;
}
/**
* Calculates rate per second. Resistant to counter reset.
* @param {*} datapoints
*/
function rate(datapoints) {
var newSeries = [];
var point = void 0,
point_prev = void 0;
var valueDelta = 0;
var timeDelta = 0;
for (var i = 1; i < datapoints.length; i++) {
point = datapoints[i];
point_prev = datapoints[i - 1];
// Convert ms to seconds
timeDelta = (point[POINT_TIMESTAMP] - point_prev[POINT_TIMESTAMP]) / 1000;
// Handle counter reset - use previous value
if (point[POINT_VALUE] >= point_prev[POINT_VALUE]) {
valueDelta = (point[POINT_VALUE] - point_prev[POINT_VALUE]) / timeDelta;
}
newSeries.push([valueDelta, point[POINT_TIMESTAMP]]);
}
return newSeries;
}
function simpleMovingAverage(datapoints, n) {
var sma = [];
var w_sum = void 0;
var w_avg = null;
var w_count = 0;
// Initial window
for (var j = n; j > 0; j--) {
if (datapoints[n - j][POINT_VALUE] !== null) {
w_avg += datapoints[n - j][POINT_VALUE];
w_count++;
}
}
if (w_count > 0) {
w_avg = w_avg / w_count;
} else {
w_avg = null;
}
sma.push([w_avg, datapoints[n - 1][POINT_TIMESTAMP]]);
for (var i = n; i < datapoints.length; i++) {
// Insert next value
if (datapoints[i][POINT_VALUE] !== null) {
w_sum = w_avg * w_count;
w_avg = (w_sum + datapoints[i][POINT_VALUE]) / (w_count + 1);
w_count++;
}
// Remove left side point
if (datapoints[i - n][POINT_VALUE] !== null) {
w_sum = w_avg * w_count;
if (w_count > 1) {
w_avg = (w_sum - datapoints[i - n][POINT_VALUE]) / (w_count - 1);
w_count--;
} else {
w_avg = null;
w_count = 0;
}
}
sma.push([w_avg, datapoints[i][POINT_TIMESTAMP]]);
}
return sma;
}
function expMovingAverage(datapoints, n) {
var ema = [datapoints[0]];
var ema_prev = datapoints[0][POINT_VALUE];
var ema_cur = void 0;
var a = void 0;
if (n > 1) {
// Calculate a from window size
a = 2 / (n + 1);
// Initial window, use simple moving average
var w_avg = null;
var w_count = 0;
for (var j = n; j > 0; j--) {
if (datapoints[n - j][POINT_VALUE] !== null) {
w_avg += datapoints[n - j][POINT_VALUE];
w_count++;
}
}
if (w_count > 0) {
w_avg = w_avg / w_count;
// Actually, we should set timestamp from datapoints[n-1] and start calculation of EMA from n.
// But in order to start EMA from first point (not from Nth) we should expand time range and request N additional
// points outside left side of range. We can't do that, so this trick is used for pretty view of first N points.
// We calculate AVG for first N points, but then start from 2nd point, not from Nth. In general, it means we
// assume that previous N values (0-N, 0-(N-1), ..., 0-1) have the same average value as a first N values.
ema = [[w_avg, datapoints[0][POINT_TIMESTAMP]]];
ema_prev = w_avg;
n = 1;
}
} else {
// Use predefined a and start from 1st point (use it as initial EMA value)
a = n;
n = 1;
}
for (var i = n; i < datapoints.length; i++) {
if (datapoints[i][POINT_VALUE] !== null) {
ema_cur = a * datapoints[i][POINT_VALUE] + (1 - a) * ema_prev;
ema_prev = ema_cur;
ema.push([ema_cur, datapoints[i][POINT_TIMESTAMP]]);
} else {
ema.push([null, datapoints[i][POINT_TIMESTAMP]]);
}
}
return ema;
}
function COUNT(values) {
return values.length;
}
function SUM(values) {
var sum = null;
for (var i = 0; i < values.length; i++) {
if (values[i] !== null) {
sum += values[i];
}
}
return sum;
}
function AVERAGE(values) {
var values_non_null = getNonNullValues(values);
if (values_non_null.length === 0) {
return null;
}
return SUM(values_non_null) / values_non_null.length;
}
function getNonNullValues(values) {
var values_non_null = [];
for (var i = 0; i < values.length; i++) {
if (values[i] !== null) {
values_non_null.push(values[i]);
}
}
return values_non_null;
}
function MIN(values) {
return _.min(values);
}
function MAX(values) {
return _.max(values);
}
function MEDIAN(values) {
var sorted = _.sortBy(values);
return sorted[Math.floor(sorted.length / 2)];
}
///////////////////////
// Utility functions //
///////////////////////
/**
* For given point calculate corresponding time frame.
*
* |__*_|_*__|___*| -> |*___|*___|*___|
*
* @param {*} timestamp
* @param {*} ms_interval
*/
function getPointTimeFrame(timestamp, ms_interval) {
return Math.floor(timestamp / ms_interval) * ms_interval;
}
function sortByTime(series) {
return _.sortBy(series, function (point) {
return point[1];
});
}
/**
* Fill empty front and end of series by zeroes.
*
* | *** | | *** |
* |___ ___| -> |*** ***|
* @param {*} series
* @param {*} timestamps
*/
function fillZeroes(series, timestamps) {
var prepend = [];
var append = [];
var new_point = void 0;
for (var i = 0; i < timestamps.length; i++) {
if (timestamps[i] < series[0][POINT_TIMESTAMP]) {
new_point = [0, timestamps[i]];
prepend.push(new_point);
} else if (timestamps[i] > series[series.length - 1][POINT_TIMESTAMP]) {
new_point = [0, timestamps[i]];
append.push(new_point);
}
}
return _.concat(_.concat(prepend, series), append);
}
/**
* Interpolate series with gaps
*/
function interpolateSeries(series) {
var left, right;
// Interpolate series
for (var i = series.length - 1; i >= 0; i--) {
if (!series[i][0]) {
left = findNearestLeft(series, i);
right = findNearestRight(series, i);
if (!left) {
left = right;
}
if (!right) {
right = left;
}
series[i][0] = linearInterpolation(series[i][1], left, right);
}
}
return series;
}
function linearInterpolation(timestamp, left, right) {
if (left[1] === right[1]) {
return (left[0] + right[0]) / 2;
} else {
return left[0] + (right[0] - left[0]) / (right[1] - left[1]) * (timestamp - left[1]);
}
}
function findNearestRight(series, pointIndex) {
for (var i = pointIndex; i < series.length; i++) {
if (series[i][0] !== null) {
return series[i];
}
}
return null;
}
function findNearestLeft(series, pointIndex) {
for (var i = pointIndex; i > 0; i--) {
if (series[i][0] !== null) {
return series[i];
}
}
return null;
}
////////////
// Export //
////////////
return {
setters: [function (_lodash) {
_ = _lodash.default;
}, function (_utils) {
utils = _utils;
}],
execute: function () {
POINT_VALUE = 0;
POINT_TIMESTAMP = 1;
exportedFunctions = {
downsample: downsample,
groupBy: groupBy,
groupBy_perf: groupBy_perf,
sumSeries: sumSeries,
scale: scale,
scale_perf: scale_perf,
delta: delta,
rate: rate,
simpleMovingAverage: simpleMovingAverage,
expMovingAverage: expMovingAverage,
SUM: SUM,
COUNT: COUNT,
AVERAGE: AVERAGE,
MIN: MIN,
MAX: MAX,
MEDIAN: MEDIAN
};
_export('default', exportedFunctions);
}
};
});
//# sourceMappingURL=timeseries.js.map