rewrite wrapper

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

stats.go

@@ -0,0 +1,41 @@
+package wrapper // import "go.unistack.org/micro-wrapper-sql/v3"
+
+import (
+	"context"
+	"database/sql"
+	"time"
+)
+
+type Statser interface {
+	Stats() sql.DBStats
+}
+
+func NewStatsMeter(ctx context.Context, db Statser, opts ...Option) {
+	options := NewOptions(opts...)
+
+	go func() {
+		ticker := time.NewTicker(options.MeterStatsInterval)
+		defer ticker.Stop()
+
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case <-ticker.C:
+				if db == nil {
+					return
+				}
+				stats := db.Stats()
+				options.Meter.Counter(MaxOpenConnections).Set(uint64(stats.MaxOpenConnections))
+				options.Meter.Counter(OpenConnections).Set(uint64(stats.OpenConnections))
+				options.Meter.Counter(InuseConnections).Set(uint64(stats.InUse))
+				options.Meter.Counter(IdleConnections).Set(uint64(stats.Idle))
+				options.Meter.Counter(WaitConnections).Set(uint64(stats.WaitCount))
+				options.Meter.FloatCounter(BlockedSeconds).Set(stats.WaitDuration.Seconds())
+				options.Meter.Counter(MaxIdleClosed).Set(uint64(stats.MaxIdleClosed))
+				options.Meter.Counter(MaxIdletimeClosed).Set(uint64(stats.MaxIdleTimeClosed))
+				options.Meter.Counter(MaxLifetimeClosed).Set(uint64(stats.MaxLifetimeClosed))
+			}
+		}
+	}()
+}