feat(wip): leaderboard pagination (resolve #417) [ci-skip]

models/shared.go

@@ -34,6 +34,11 @@ type KeyedInterval struct {
 	Key *IntervalKey
 }
 
+type PageParams struct {
+	Page     int `json:"page"`
+	PageSize int `json:"page_size"`
+}
+
 // CustomTime is a wrapper type around time.Time, mainly used for the purpose of transparently unmarshalling Python timestamps in the format <sec>.<nsec> (e.g. 1619335137.3324468)
 type CustomTime time.Time
 
@@ -99,3 +104,17 @@ func (j CustomTime) T() time.Time {
 func (j CustomTime) Valid() bool {
 	return j.T().Unix() >= 0
 }
+
+func (p *PageParams) Limit() int {
+	if p.PageSize < 0 {
+		return 0
+	}
+	return p.PageSize
+}
+
+func (p *PageParams) Offset() int {
+	if p.PageSize <= 0 {
+		return 0
+	}
+	return (p.Page - 1) * p.PageSize
+}