Documentation
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Overview ¶
Package windowed expresses time-bucketed aggregations on top of any structural monoid. State is keyed by (entity, bucket_id) where bucket_id is computed from event time and the configured Granularity. Queries assemble sliding windows by Combining the N most recent buckets through the wrapped monoid. DDB TTL handles eviction past Retention.
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func MergeBuckets ¶
MergeBuckets folds bucket values via the inner monoid in stable order. Used by the query layer to produce sliding-window results from per-bucket reads.
Types ¶
type Config ¶
type Config struct {
// Granularity is the size of each tumbling bucket (e.g. 24h for daily, 1h for hourly).
// Smaller granularity means finer query precision and higher state cost.
Granularity time.Duration
// Retention is how long buckets are kept before TTL eviction. Sliding-window queries
// can ask for any range up to Retention.
Retention time.Duration
// EventTimeField, if non-empty, names the field on the source record from which to
// extract event-time. If empty, processing-time is used. Backends honor this when
// computing BucketID.
EventTimeField string
}
Config describes the bucket layout for a windowed aggregation.
func Daily ¶
Daily returns a Config with 24h granularity and the given retention. The most common configuration for "last N days of X"-style counters.
func Hourly ¶
Hourly returns a Config with 1h granularity and the given retention. Suitable for "last N hours" or "last 7 days at hourly resolution" queries.
func Minute ¶
Minute returns a Config with 1-minute granularity and the given retention. Useful for high-resolution short-window aggregations (last 5 minutes, last hour at per-minute resolution). At this granularity, "last 7 days" reads 10080 buckets per query — consider hierarchical roll-ups for queries spanning more than ~24h.
func (Config) BucketID ¶
BucketID assigns the given time to a bucket according to Granularity. Buckets are tumbling and aligned to the Unix epoch.
func (Config) BucketRange ¶
BucketRange returns the inclusive range of bucket IDs that cover [start, end].
func (Config) LastN ¶
LastN returns the bucket-ID range covering the most recent d duration ending at now. The number of buckets returned is ceil(d / Granularity); the upper bound is the bucket containing now and the range extends backward that many buckets. So for daily granularity, "last 7 days" returns 7 buckets (today plus 6 prior), not 8.
Source Files