redisx 
redisx is a library of Go utilities built on the redigo redis client library.
IntervalSet
Creating very large numbers of Redis keys can hurt performance, but putting them all in a single set requires that they all have the same expiration. Marker is a way to have multiple sets based on time intervals, accessible like a single set. You trade accuracy of expiry times for a significantly reduced key space. For example using 2 intervals of 24 hours:
marker := NewIntervalSet("foos", time.Hour*24, 2)
marker.Add(rc, "A") // time is 2021-12-02T09:00
...
marker.Add(rc, "B") // time is 2021-12-03T10:00
marker.Add(rc, "C") // time is 2021-12-03T11:00
Creates 2 Redis sets like:
foos:2021-12-02 => {"A"} // expires at 2021-12-04T09:00
foos:2021-12-03 => {"B", "C"} // expires at 2021-12-05T11:00
But can be accessed like a single set:
marker.Contains(rc, "A") // true
marker.Contains(rc, "B") // true
marker.Contains(rc, "D") // false
IntervalHash
Same idea as IntervalSet but for hashes, and works well for caching values. For example using 2 intervals of 1 hour:
cache := NewIntervalHash("foos", time.Hour, 2)
cache.Set(rc, "A", "1") // time is 2021-12-02T09:10
...
cache.Set(rc, "B", "2") // time is 2021-12-02T10:15
cache.Set(rc, "C", "3") // time is 2021-12-02T10:20
Creates 2 Redis hashes like:
foos:2021-12-02T09:00 => {"A": "1"} // expires at 2021-12-02T11:10
foos:2021-12-02T10:00 => {"B": "2", "C": "3"} // expires at 2021-12-02T12:20
But can be accessed like a single hash:
cache.Get(rc, "A") // "1"
cache.Get(rc, "B") // "2"
cache.Get(rc, "D") // ""
IntervalSeries
When getting a value from an IntervalHash you're getting the newest value by looking back through the intervals. IntervalSeries however lets you get an accumulated value from each interval.
For example using 3 intervals of 1 hour:
series := NewIntervalSeries("foos", time.Hour, 3)
series.Record(rc, "A", 1) // time is 2021-12-02T09:10
series.Record(rc, "A", 2) // time is 2021-12-02T09:15
...
series.Record(rc, "A", 3) // time is 2021-12-02T10:15
series.Record(rc, "A", 4) // time is 2021-12-02T10:20
...
series.Record(rc, "A", 5) // time is 2021-12-02T11:25
series.Record(rc, "B", 1) // time is 2021-12-02T11:30
Creates 3 Redis hashes like:
foos:2021-12-02T09:00 => {"A": "3"} // expires at 2021-12-02T12:15
foos:2021-12-02T10:00 => {"A": "7"} // expires at 2021-12-02T13:20
foos:2021-12-02T11:00 => {"A": "5", "B": "1"} // expires at 2021-12-02T14:30
But lets us retrieve values across intervals:
series.Get(rc, "A") // [5, 7, 3]
series.Get(rc, "B") // [1, 0, 0]
series.Get(rc, "C") // [0, 0, 0]
CappedZSet
The CappedZSet type is based on a sorted set but enforces a cap on size, by only retaining the highest ranked members.
cset := NewCappedZSet("foos", 3, time.Hour*24)
cset.Add(rc, "A", 1)
cset.Add(rc, "C", 3)
cset.Add(rc, "D", 4)
cset.Add(rc, "B", 2)
cset.Add(rc, "E", 5)
cset.Members(rc) // ["C", "D", "E"] / [3, 4, 5]
Testing Asserts
The assertredis package contains several asserts useful for testing the state of a Redis database.
rp := assertredis.TestDB()
assertredis.Keys(t, rp, []string{"foo", "bar"})
assertredis.Get(t, rp, "foo", "123")
assertredis.SMembers(t, rp, "foo_set", []string{"123", "234"})
