Global

Methods

addToOrdered(arr, timestampSelector, …values)

Adds one or more elements to a time-ordered array of items, inserting them in chronological order.
Parameters:
Name Type Attributes Description
arr Array destination array for new element(s).
timestampSelector timestampSelector function to extract a timestamp from an element.
values any <repeatable>
 value(s) to add to the array.
Source:

addToOrderedAndEvictBefore(arr, startTime, timestampSelector, …values)

Adds one or more elements to a time-ordered array of items, inserting them in chronological order. Any elements in the array with a timestamp prior to the supplied startTime argument will be evicted from the destination array.
Parameters:
Name Type Attributes Description
arr Array destination array for new element(s).
startTime Date | number start time (inclusive) of the first allowed element in the destination array.
timestampSelector timestampSelector function to extract a timestamp from an element.
values any <repeatable>
 value(s) to add to the array.
Source:

addToOrderedAndEvictOldest(arr, maxArraySize, timestampSelector, …values)

Adds one or more elements to a time-ordered array of items, inserting them in chronological order. If the size of the destination array exceeds the supplied maxArraySize argument, the oldest elements in the destination array will be evicted.
Parameters:
Name Type Attributes Description
arr Array destination array for new element(s).
maxArraySize number max allowed size of destination array before eviction begins.
timestampSelector timestampSelector function to extract a timestamp from an element.
values any <repeatable>
 value(s) to add to the array.
Source:

addToOrderedAndEvictSessions(arr, maxSessionCount, timestampSelector, idleThreshold, …values)

Adds one or more elements to a time-ordered array of items, inserting them in chronological order. If the number of sessions in the destination array exceeds the supplied maxSessionCount argument, elements in the oldest session(s) in the destination array will be evicted.
Parameters:
Name Type Attributes Description
arr Array destination array for new element(s).
maxSessionCount number max allowed number of sessions.
timestampSelector timestampSelector function to extract a timestamp from an element.
idleThreshold number max allowed time gap between elements before a new session is started, in milliseconds.
values any <repeatable>
 value(s) to add to the array.
Source:

removeFirstItems(arr, count)

Perform in-place removal of the first N elements in an array.
Parameters:
Name Type Description
arr Array array to be modified.
count number Number of elements to remove from the front of the array.
Source:

toSessionWindows(sourceArray, timestampSelector, idleThreshold) → {Array.<TimeWindow>}

Transforms an ordered array into an array of session windows. The source array must be sorted chronologically.
Parameters:
Name Type Description
sourceArray Array Array of time-ordered elements to transform.
timestampSelector timestampSelector Function to extract a timestamp from elements in the source array.
idleThreshold number max allowed time gap between elements before a new session is started, in milliseconds.
Source:
Returns:
An array of TimeWindow instances.
Type
Array.<TimeWindow>

toSlidingWindows(sourceArray, timestampSelector, windowDuration, every, start, end) → {Array.<TimeWindow>}

Transforms an ordered array into an array of sliding windows. The source array must be sorted chronologically.
Parameters:
Name Type Description
sourceArray Array Array of time-ordered elements to transform.
timestampSelector timestampSelector Function to extract a timestamp from elements in the source array.
windowDuration number Duration of each time window in milliseconds. This is a maximum value that will be shortened for the last window(s) in the returned sequence.
every number The period of time, in milliseconds, between the start of each sliding window.
start number Start time (inclusive) of the first sliding window, expressed as milliseconds elapsed since January 1, 1970 00:00:00 UTC. If undefined, the timestamp of the array's first element will be used.
end number End time (exclusive) for the last sliding window(s), expressed as milliseconds elapsed since January 1, 1970 00:00:00 UTC. If undefined, the timestamp of the array's last element will be used, and the last window's end time will be inclusive.
Source:
Returns:
An array of TimeWindow instances.
Type
Array.<TimeWindow>

toTumblingWindows(sourceArray, timestampSelector, windowDuration, start, end) → {Array.<TimeWindow>}

Transforms an ordered array into an array of non-overlapped, fixed-time windows. The source array must be sorted chronologically.
Parameters:
Name Type Description
sourceArray Array Array of time-ordered elements to transform.
timestampSelector timestampSelector Function to extract a timestamp from elements in the source array.
windowDuration number Duration of each time window in milliseconds. This is a maximum value that may be shortened for the last window in the returned sequence.
start number Start time (inclusive) of the first sliding window, expressed as milliseconds elapsed since January 1, 1970 00:00:00 UTC. If undefined, the timestamp of the array's first element will be used.
end number End time (exclusive) for the last sliding window(s), expressed as milliseconds elapsed since January 1, 1970 00:00:00 UTC. If undefined, the timestamp of the array's last element will be used, and the last window's end time will be inclusive.
Source:
Returns:
An array of TimeWindow instances.
Type
Array.<TimeWindow>

Type Definitions

forEachCallback(currentValue, indexopt, windowopt)

Function that is executed on each element in a TimeWindow, taking three arguments:
Parameters:
Name Type Attributes Description
currentValue any The current element in the TimeWindow being processed.
index number <optional>
 The index of the current element being processed in the array.
window TimeWindow <optional>
 The TimeWindow that forEach() was called upon.
Source:

mapCallback(currentValue, indexopt, windowopt) → {any}

Function that produces an element for the new Array, taking three arguments:
Parameters:
Name Type Attributes Description
currentValue any The current element in the TimeWindow being processed.
index number <optional>
 The index of the current element being processed in the array.
window TimeWindow <optional>
 The TimeWindow that map() was called upon.
Source:
Returns:
Transformed element.
Type
any

predicateCallback(currentValue, indexopt, windowopt) → {boolean}

Predicate used to test each element the TimeWindow. Return true if the element satisifies the condition, false otherwise. Three arguments are provided to this callback:
Parameters:
Name Type Attributes Description
currentValue any The current element in the TimeWindow being tested.
index number <optional>
 The index of the current element being processed in the array.
window TimeWindow <optional>
 The TimeWindow being evaluated.
Source:
Returns:
true if the element satisfies the condition, false otherwise.
Type
boolean

reduceCallback(accumulator, currentValue, indexopt, windowopt) → {any}

Reducer function to execute on each element in the TimeWindow, taking four arguments:
Parameters:
Name Type Attributes Description
accumulator any The accumulator accumulates the callback's return values; it is the accumulated value previously returned in the last invocation of the callback, or initialValue, if supplied.
currentValue any The current element in the TimeWindow being processed.
index number <optional>
 The index of the current element being processed in the array.
window TimeWindow <optional>
 The TimeWindow that reduce() was called upon.
Source:
Returns:
The accumulating value that is eventually returned to the reduce() caller. This returned value is assigned to the accumulator, whose value is remembered across each iteration throughout the window and ultimately becomes the final, single resulting value.
Type
any

timestampSelector(elem) → {number}

User-supplied callback that extracts a timestamp from an element in a time-ordered array of events.
Parameters:
Name Type Description
elem any Timestamped element in a time-ordered array of events.
Source:
Returns:
The time that the elem argument occurred, represented as milliseconds elapsed since January 1, 1970 00:00:00 UTC.
Type
number