mox!

vendor/github.com/mjl-/bstore/stats.go

@@ -0,0 +1,105 @@
+package bstore
+
+// StatsKV represent operations on the underlying BoltDB key/value store.
+type StatsKV struct {
+	Get    uint
+	Put    uint // For Stats.Bucket, this counts calls of CreateBucket.
+	Delete uint
+	Cursor uint // Any cursor operation: Seek/First/Last/Next/Prev.
+}
+
+// Stats tracks DB/Tx/Query statistics, mostly counters.
+type Stats struct {
+	// Number of read-only or writable transactions. Set for DB only.
+	Reads  uint
+	Writes uint
+
+	Bucket  StatsKV // Use of buckets.
+	Records StatsKV // Use of records bucket for types.
+	Index   StatsKV // Use of index buckets for types.
+
+	// Operations that modify the database. Each record is counted, e.g.
+	// for a query that updates/deletes multiple records.
+	Get    uint
+	Insert uint
+	Update uint
+	Delete uint
+
+	Queries       uint   // Total queries executed.
+	PlanTableScan uint   // Full table scans.
+	PlanPK        uint   // Primary key get.
+	PlanUnique    uint   // Full key Unique index get.
+	PlanPKScan    uint   // Scan over primary keys.
+	PlanIndexScan uint   // Scan over index.
+	Sort          uint   // In-memory collect and sort.
+	LastType      string // Last type queried.
+	LastIndex     string // Last index for LastType used for a query, or empty.
+	LastOrdered   bool   // Whether last scan (PK or index) use was ordered, e.g. for sorting or because of a comparison filter.
+	LastAsc       bool   // If ordered, whether last index scan was ascending.
+}
+
+func (skv *StatsKV) add(n StatsKV) {
+	skv.Get += n.Get
+	skv.Put += n.Put
+	skv.Delete += n.Delete
+	skv.Cursor += n.Cursor
+}
+
+func (skv *StatsKV) sub(n StatsKV) {
+	skv.Get -= n.Get
+	skv.Put -= n.Put
+	skv.Delete -= n.Delete
+	skv.Cursor -= n.Cursor
+}
+
+func (st *Stats) add(n Stats) {
+	st.Reads += n.Reads
+	st.Writes += n.Writes
+
+	st.Bucket.add(n.Bucket)
+	st.Records.add(n.Records)
+	st.Index.add(n.Index)
+
+	st.Get += n.Get
+	st.Insert += n.Insert
+	st.Update += n.Update
+	st.Delete += n.Delete
+
+	st.Queries += n.Queries
+	st.PlanTableScan += n.PlanTableScan
+	st.PlanPK += n.PlanPK
+	st.PlanUnique += n.PlanUnique
+	st.PlanPKScan += n.PlanPKScan
+	st.PlanIndexScan += n.PlanIndexScan
+	st.Sort += n.Sort
+
+	st.LastType = n.LastType
+	st.LastIndex = n.LastIndex
+	st.LastOrdered = n.LastOrdered
+	st.LastAsc = n.LastAsc
+}
+
+// Sub returns st with the counters from o subtracted.
+func (st Stats) Sub(o Stats) Stats {
+	st.Reads -= o.Reads
+	st.Writes -= o.Writes
+
+	st.Bucket.sub(o.Bucket)
+	st.Records.sub(o.Records)
+	st.Index.sub(o.Index)
+
+	st.Get -= o.Get
+	st.Insert -= o.Insert
+	st.Update -= o.Update
+	st.Delete -= o.Delete
+
+	st.Queries -= o.Queries
+	st.PlanTableScan -= o.PlanTableScan
+	st.PlanPK -= o.PlanPK
+	st.PlanUnique -= o.PlanUnique
+	st.PlanPKScan -= o.PlanPKScan
+	st.PlanIndexScan -= o.PlanIndexScan
+	st.Sort -= o.Sort
+
+	return st
+}