Time Average Datastructure for Redis.

This data structure provides the ability to efficiently produce an average rate of events, and distinct events occuring over a set time frame. This value can then be divided over time to produce an average rate.

• "ta*" commands track the occurance of events over time
• "tu*" commands track unique events happening over time

Event Commands:

tahit [interval] [by] [timestamp] [key1] [key2...]

Signal that the event has happened, increment each [key] by the the value of [by] within the scope of [timestamp].

Returns the new sum over time value for each key (bulk reply) based on the current [timestamp]. The [interval] between buckets (how much time does a bucket represent) must be provided for this calculation.

tacalc [interval] [timestamp] [key]

Returns the sum over time value for a given key based on the current [timestamp]. The [interval] between buckets (how much time does a bucket represent) must be provided for this calculation.

Unique Event Commands:

tuhit [interval] [unique value] [timestamp] [key1] [key2...]

Signal that the event has happened, with the [unique value]. Increment each [key] if the [unique value] is unique within the scope of [timestamp].

Returns the new sum over time value for each key (bulk reply) based on the current [timestamp]. The [interval] between buckets (how much time does a bucket represent) must be provided for this calculation.

tuupdate [interval] [unique values] [timestamp] [key1] [key2...]

Signal that the event has happened, with the each value in [unique values]. Increment each [key] if the unique value is unique within the scope of [timestamp]. A unique value is extracted from [unique values]. [unique values] is split by the 0x00 (\x00) character. This function is not binary safe for [unique values].

Returns OK if successful.

tucalc [interval] [timestamp] [key]

Returns the sum of unqiue events over time value for a given key based on the current [timestamp]. The [interval] between buckets (how much time does a bucket represent) must be provided for this calculation.

Also returns the time this structure was reated

Data Structure:

The number of buckets is detimrined by a compile time constants.

• TA_BUCKETS defaults to 20
• TU_BUCKETS defaults to 6

Time Average

 ---------------------------------------------
 |               |         |         |
 |  Last Updated | Bucket0 | Bucket1 | ....
 |     32bit     |  32bit  |  32bit  |
 |               |         |         |
 ---------------------------------------------

Time Unique Average

 ------------------------------------------------------------
 |               |              |         |         |
 |  Last Updated | Time Created | Bucket0 | Bucket1 | ....
 |     32bit     |     32bit    |   HLL   |   HLL   |
 |               |              |         |         |
 ------------------------------------------------------------

Memory Requirements

• Time average objects require 84 bytes of memory per object.
• Time unique average objects require UP TO 73Kb of memory per object.