cmd/syncthing: Add debug commands to cli (#7503)

cmd/syncthing/cli/index_accounting.go

@@ -0,0 +1,64 @@
+// Copyright (C) 2020 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package cli
+
+import (
+	"fmt"
+	"os"
+	"text/tabwriter"
+
+	"github.com/urfave/cli"
+)
+
+// indexAccount prints key and data size statistics per class
+func indexAccount(*cli.Context) error {
+	ldb, err := getDB()
+	if err != nil {
+		return err
+	}
+
+	it, err := ldb.NewPrefixIterator(nil)
+	if err != nil {
+		return err
+	}
+
+	var ksizes [256]int
+	var dsizes [256]int
+	var counts [256]int
+	var max [256]int
+
+	for it.Next() {
+		key := it.Key()
+		t := key[0]
+		ds := len(it.Value())
+		ks := len(key)
+		s := ks + ds
+
+		counts[t]++
+		ksizes[t] += ks
+		dsizes[t] += ds
+		if s > max[t] {
+			max[t] = s
+		}
+	}
+
+	tw := tabwriter.NewWriter(os.Stdout, 1, 1, 1, ' ', tabwriter.AlignRight)
+	toti, totds, totks := 0, 0, 0
+	for t := range ksizes {
+		if ksizes[t] > 0 {
+			// yes metric kilobytes 🤘
+			fmt.Fprintf(tw, "0x%02x:\t%d items,\t%d KB keys +\t%d KB data,\t%d B +\t%d B avg,\t%d B max\t\n", t, counts[t], ksizes[t]/1000, dsizes[t]/1000, ksizes[t]/counts[t], dsizes[t]/counts[t], max[t])
+			toti += counts[t]
+			totds += dsizes[t]
+			totks += ksizes[t]
+		}
+	}
+	fmt.Fprintf(tw, "Total\t%d items,\t%d KB keys +\t%d KB data.\t\n", toti, totks/1000, totds/1000)
+	tw.Flush()
+
+	return nil
+}