counter

type CMSGrowParams struct {
	SkipRateDecay int     // how often (in calls to Inc) the skip rate is halved (this makes it an exponential moving average)
	Threshold     float64 // at what skip ratio should we grow W
	Ratio         float64 // how much to grow W each time
	MaxW          int     // cap for W
}

type CMSketchParams struct {
	W    int // width of sketch
	D    int // depth of sketch
	Grow CMSGrowParams
}

type Counter interface {
	// GetPass tracks a value per key, which may be lossy or approximate. It increments the
	// value by inc and returns the new value. The value returned must be >= base.
	GetPass(key string, base, inc int64) int64
	// EstimateDistinctKeys returns an estimate of the number of distinct keys in the counter.
	EstimateDistinctKeys() int
	// Get the counts for a small number of top keys (the maximum keys returned will be limited
	// by the Counter's configuration). Not guaranteed to return the exact top.
	TopK() []TopKEntry
}

type CounterParams struct {
	MapLimit int
	CMS      CMSketchParams
}

type TopKEntry struct {
	Key   string
	Count int64
}