Implement paging and refactor stores to match new store interface with paging

storage/store/memory/uptime.go

@@ -0,0 +1,119 @@
+package memory
+
+import (
+	"log"
+	"time"
+
+	"github.com/TwinProduction/gatus/core"
+)
+
+const (
+	numberOfHoursInTenDays = 10 * 24
+	sevenDays              = 7 * 24 * time.Hour
+)
+
+// processUptimeAfterResult processes the result by extracting the relevant from the result and recalculating the uptime
+// if necessary
+func processUptimeAfterResult(uptime *core.Uptime, result *core.Result) {
+	// XXX: Remove this on v3.0.0
+	if len(uptime.SuccessfulExecutionsPerHour) != 0 || len(uptime.TotalExecutionsPerHour) != 0 {
+		migrateUptimeToHourlyStatistics(uptime)
+	}
+	if uptime.HourlyStatistics == nil {
+		uptime.HourlyStatistics = make(map[int64]*core.HourlyUptimeStatistics)
+	}
+	unixTimestampFlooredAtHour := result.Timestamp.Truncate(time.Hour).Unix()
+	hourlyStats, _ := uptime.HourlyStatistics[unixTimestampFlooredAtHour]
+	if hourlyStats == nil {
+		hourlyStats = &core.HourlyUptimeStatistics{}
+		uptime.HourlyStatistics[unixTimestampFlooredAtHour] = hourlyStats
+	}
+	if result.Success {
+		hourlyStats.SuccessfulExecutions++
+	}
+	hourlyStats.TotalExecutions++
+	hourlyStats.TotalExecutionsResponseTime += uint64(result.Duration.Milliseconds())
+	// Clean up only when we're starting to have too many useless keys
+	// Note that this is only triggered when there are more entries than there should be after
+	// 10 days, despite the fact that we are deleting everything that's older than 7 days.
+	// This is to prevent re-iterating on every `processUptimeAfterResult` as soon as the uptime has been logged for 7 days.
+	if len(uptime.HourlyStatistics) > numberOfHoursInTenDays {
+		sevenDaysAgo := time.Now().Add(-(sevenDays + time.Hour)).Unix()
+		for hourlyUnixTimestamp := range uptime.HourlyStatistics {
+			if sevenDaysAgo > hourlyUnixTimestamp {
+				delete(uptime.HourlyStatistics, hourlyUnixTimestamp)
+			}
+		}
+	}
+	if result.Success {
+		// Recalculate uptime if at least one of the 1h, 24h or 7d uptime are not 100%
+		// If they're all 100%, then recalculating the uptime would be useless unless
+		// the result added was a failure (!result.Success)
+		if uptime.LastSevenDays != 1 || uptime.LastTwentyFourHours != 1 || uptime.LastHour != 1 {
+			recalculateUptime(uptime)
+		}
+	} else {
+		// Recalculate uptime if at least one of the 1h, 24h or 7d uptime are not 0%
+		// If they're all 0%, then recalculating the uptime would be useless unless
+		// the result added was a success (result.Success)
+		if uptime.LastSevenDays != 0 || uptime.LastTwentyFourHours != 0 || uptime.LastHour != 0 {
+			recalculateUptime(uptime)
+		}
+	}
+}
+
+func recalculateUptime(uptime *core.Uptime) {
+	uptimeBrackets := make(map[string]uint64)
+	now := time.Now()
+	// The oldest uptime bracket starts 7 days ago, so we'll start from there
+	timestamp := now.Add(-sevenDays)
+	for now.Sub(timestamp) >= 0 {
+		hourlyUnixTimestamp := timestamp.Truncate(time.Hour).Unix()
+		hourlyStats := uptime.HourlyStatistics[hourlyUnixTimestamp]
+		if hourlyStats == nil || hourlyStats.TotalExecutions == 0 {
+			timestamp = timestamp.Add(time.Hour)
+			continue
+		}
+		uptimeBrackets["7d_success"] += hourlyStats.SuccessfulExecutions
+		uptimeBrackets["7d_total"] += hourlyStats.TotalExecutions
+		if now.Sub(timestamp) <= 24*time.Hour {
+			uptimeBrackets["24h_success"] += hourlyStats.SuccessfulExecutions
+			uptimeBrackets["24h_total"] += hourlyStats.TotalExecutions
+		}
+		if now.Sub(timestamp) <= time.Hour {
+			uptimeBrackets["1h_success"] += hourlyStats.SuccessfulExecutions
+			uptimeBrackets["1h_total"] += hourlyStats.TotalExecutions
+		}
+		timestamp = timestamp.Add(time.Hour)
+	}
+	if uptimeBrackets["7d_total"] > 0 {
+		uptime.LastSevenDays = float64(uptimeBrackets["7d_success"]) / float64(uptimeBrackets["7d_total"])
+	}
+	if uptimeBrackets["24h_total"] > 0 {
+		uptime.LastTwentyFourHours = float64(uptimeBrackets["24h_success"]) / float64(uptimeBrackets["24h_total"])
+	}
+	if uptimeBrackets["1h_total"] > 0 {
+		uptime.LastHour = float64(uptimeBrackets["1h_success"]) / float64(uptimeBrackets["1h_total"])
+	}
+}
+
+// XXX: Remove this on v3.0.0
+// Deprecated
+func migrateUptimeToHourlyStatistics(uptime *core.Uptime) {
+	log.Println("[migrateUptimeToHourlyStatistics] Got", len(uptime.SuccessfulExecutionsPerHour), "entries for successful executions and", len(uptime.TotalExecutionsPerHour), "entries for total executions")
+	uptime.HourlyStatistics = make(map[int64]*core.HourlyUptimeStatistics)
+	for hourlyUnixTimestamp, totalExecutions := range uptime.TotalExecutionsPerHour {
+		if totalExecutions == 0 {
+			log.Println("[migrateUptimeToHourlyStatistics] Skipping entry at", hourlyUnixTimestamp, "because total number of executions is 0")
+			continue
+		}
+		uptime.HourlyStatistics[hourlyUnixTimestamp] = &core.HourlyUptimeStatistics{
+			TotalExecutions:             totalExecutions,
+			SuccessfulExecutions:        uptime.SuccessfulExecutionsPerHour[hourlyUnixTimestamp],
+			TotalExecutionsResponseTime: 0,
+		}
+	}
+	log.Println("[migrateUptimeToHourlyStatistics] Migrated", len(uptime.HourlyStatistics), "entries")
+	uptime.SuccessfulExecutionsPerHour = nil
+	uptime.TotalExecutionsPerHour = nil
+}