v1.2.0: skip unchanged writes, transactional schema/root counters, snapshot replay for meta:events 0-0 (drops boot republish), collect-once search driver

internal/storage/write_bench_test.go

@@ -57,3 +57,53 @@ func BenchmarkConcurrentRecordWrites(b *testing.B) {
 	wg.Wait()
 	b.ReportMetric(float64(b.N)/b.Elapsed().Seconds(), "records/s")
 }
+
+// BenchmarkConcurrentRepersistUnchanged is the dominant write on a permanent
+// store: a gateway re-persisting hits it already holds. The kv layer skips
+// every unchanged field, so this should cost reads only.
+func BenchmarkConcurrentRepersistUnchanged(b *testing.B) {
+	c := NewClient()
+	if err := c.Connect(filepath.Join(b.TempDir(), "bench.db")); err != nil {
+		b.Fatal(err)
+	}
+	defer c.Close()
+	const distinct = 2000
+	rec := func(i int64) map[string]string {
+		m := map[string]string{
+			"title":    fmt.Sprintf("Some Show S01E%02d", i%40),
+			"fileType": "video",
+			fmt.Sprintf("cids/bafkbench%020d", i): "true",
+		}
+		for f := 0; len(m) < 40; f++ {
+			m[fmt.Sprintf("categories/%d", f)] = "true"
+		}
+		return m
+	}
+	for i := int64(0); i < distinct; i++ {
+		if err := c.SetMetadataFlat(fmt.Sprintf("01BENCH%019d", i), rec(i)); err != nil {
+			b.Fatal(err)
+		}
+	}
+	const writers = 16
+	var next int64
+	b.ResetTimer()
+	var wg sync.WaitGroup
+	for w := 0; w < writers; w++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for {
+				i := atomic.AddInt64(&next, 1)
+				if i > int64(b.N) {
+					return
+				}
+				if err := c.SetMetadataFlat(fmt.Sprintf("01BENCH%019d", i%distinct), rec(i%distinct)); err != nil {
+					b.Error(err)
+					return
+				}
+			}
+		}()
+	}
+	wg.Wait()
+	b.ReportMetric(float64(b.N)/b.Elapsed().Seconds(), "records/s")
+}