File size: 2,910 Bytes
1c4c66b | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 | package engine
import (
"context"
"time"
"github.com/alpacahq/alpacadecimal"
"github.com/samber/lo"
"github.com/openmeterio/openmeter/openmeter/credit/balance"
"github.com/openmeterio/openmeter/openmeter/credit/grant"
"github.com/openmeterio/openmeter/openmeter/meter"
"github.com/openmeterio/openmeter/pkg/timeutil"
)
type RunParams struct {
// Meter for the current run.
Meter meter.Meter
// List of all grants that are active at the relevant period at some point.
Grants []grant.Grant
// End of the period to burn down the grants for.
Until time.Time
// Starting snapshot of the balances at the START OF THE PERIOD.
StartingSnapshot balance.Snapshot
// ResetBehavior defines the behavior of the engine when a reset is encountered.
ResetBehavior grant.ResetBehavior
// Timeline of the resets that occurred in the period.
// The resets must occur AFTER the starting snapshot and NOT AFTER the until time. (exclusive - inclusive)
Resets timeutil.SimpleTimeline
}
func (p RunParams) Clone() RunParams {
grants := make([]grant.Grant, len(p.Grants))
copy(grants, p.Grants)
resets := timeutil.NewSimpleTimeline(p.Resets.GetTimes())
res := RunParams{
Meter: p.Meter,
Grants: grants,
Until: p.Until,
StartingSnapshot: p.StartingSnapshot,
ResetBehavior: p.ResetBehavior,
Resets: resets,
}
return res
}
type RunResult struct {
// Snapshot of the balances at the END OF THE PERIOD.
Snapshot balance.Snapshot
// History of the grant burn down.
History GrantBurnDownHistory
// RunParams used to produce the result.
RunParams RunParams
}
// TotalAvailableGrantAmountAtLastPeriod is the total grant amount available in the run period:
// grant-covered usage plus remaining balances still available at the end.
func (r RunResult) TotalAvailableGrantAmountAtLastPeriod() float64 {
lastUsagePeriodHistory, _ := lo.Last(r.History.ChunkByResets())
return lastUsagePeriodHistory.TotalGrantUsage().
Add(alpacadecimal.NewFromFloat(r.Snapshot.Balance())).
InexactFloat64()
}
type Engine interface {
// Burns down all grants in the defined period by the usage amounts.
//
// When the engine outputs a balance, it doesn't discriminate what should be in that balance.
// If a grant is inactive at the end of the period, it will still be in the output.
Run(ctx context.Context, params RunParams) (RunResult, error)
}
// TODO: should return alpacadecimal instead of float64, its fine to hard depend on it for now
type QueryUsageFn func(ctx context.Context, from, to time.Time) (float64, error)
type EngineConfig struct {
QueryUsage QueryUsageFn
}
func NewEngine(conf EngineConfig) Engine {
return &engine{
EngineConfig: conf,
}
}
// engine burns down grants based on usage following the rules of Grant BurnDown.
type engine struct {
EngineConfig
}
// Ensure engine implements Engine
var _ Engine = (*engine)(nil)
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