From bf47dba1c4539ab829f58f3e19642dbb9194425f Mon Sep 17 00:00:00 2001
From: Alexander Neumann <alexander@bumpern.de>
Date: Sat, 20 Aug 2016 17:43:25 +0200
Subject: [PATCH] Add 'forget' command

---
 src/cmds/restic/cmd_forget.go | 153 ++++++++++++++++++++++++++++++++++
 1 file changed, 153 insertions(+)
 create mode 100644 src/cmds/restic/cmd_forget.go

diff --git a/src/cmds/restic/cmd_forget.go b/src/cmds/restic/cmd_forget.go
new file mode 100644
index 000000000..df6d97062
--- /dev/null
+++ b/src/cmds/restic/cmd_forget.go
@@ -0,0 +1,153 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"path"
+	"restic"
+	"restic/backend"
+)
+
+// CmdForget implements the 'forget' command.
+type CmdForget struct {
+	Last    int `short:"l" long:"keep-last" description:"keep the last n snapshots"`
+	Hourly  int `short:"H" long:"keep-hourly" description:"keep the last n hourly snapshots"`
+	Daily   int `short:"d" long:"keep-daily" description:"keep the last n daily snapshots"`
+	Weekly  int `short:"w" long:"keep-weekly" description:"keep the last n weekly snapshots"`
+	Monthly int `short:"m" long:"keep-monthly" description:"keep the last n monthly snapshots"`
+	Yearly  int `short:"y" long:"keep-yearly" description:"keep the last n yearly snapshots"`
+
+	DryRun bool `short:"n" long:"dry-run" description:"do not delete anything, just print what would be done"`
+
+	global *GlobalOptions
+}
+
+func init() {
+	_, err := parser.AddCommand("forget",
+		"removes snapshots from a repository",
+		"The forget command removes snapshots according to a policy.",
+		&CmdForget{global: &globalOpts})
+	if err != nil {
+		panic(err)
+	}
+}
+
+// Usage returns usage information for 'forget'.
+func (cmd CmdForget) Usage() string {
+	return "[snapshot ID] ..."
+}
+
+func printSnapshots(w io.Writer, snapshots restic.Snapshots) {
+	tab := NewTable()
+	tab.Header = fmt.Sprintf("%-8s  %-19s  %-10s  %s", "ID", "Date", "Host", "Directory")
+	tab.RowFormat = "%-8s  %-19s  %-10s  %s"
+
+	for _, sn := range snapshots {
+		if len(sn.Paths) == 0 {
+			continue
+		}
+		id := sn.ID()
+		tab.Rows = append(tab.Rows, []interface{}{id.Str(), sn.Time.Format(TimeFormat), sn.Hostname, sn.Paths[0]})
+
+		if len(sn.Paths) > 1 {
+			for _, path := range sn.Paths[1:] {
+				tab.Rows = append(tab.Rows, []interface{}{"", "", "", path})
+			}
+		}
+	}
+
+	tab.Write(w)
+}
+
+// Execute runs the 'forget' command.
+func (cmd CmdForget) Execute(args []string) error {
+	repo, err := cmd.global.OpenRepository()
+	if err != nil {
+		return err
+	}
+
+	lock, err := lockRepoExclusive(repo)
+	defer unlockRepo(lock)
+	if err != nil {
+		return err
+	}
+
+	err = repo.LoadIndex()
+	if err != nil {
+		return err
+	}
+
+	// first, process all snapshot IDs given as arguments
+	for _, s := range args {
+		id, err := restic.FindSnapshot(repo, s)
+		if err != nil {
+			return err
+		}
+
+		if !cmd.DryRun {
+			err = repo.Backend().Remove(backend.Snapshot, id.String())
+			if err != nil {
+				return err
+			}
+
+			cmd.global.Verbosef("removed snapshot %v\n", id.Str())
+		} else {
+			cmd.global.Verbosef("would removed snapshot %v\n", id.Str())
+		}
+
+	}
+
+	// then, load all remaining snapshots
+	snapshots, err := restic.LoadAllSnapshots(repo)
+	if err != nil {
+		return err
+	}
+
+	// group by hostname and dirs
+	type key struct {
+		Hostname string
+		Dirs     string
+	}
+
+	snapshotGroups := make(map[key]restic.Snapshots)
+
+	for _, sn := range snapshots {
+		k := key{Hostname: sn.Hostname, Dirs: path.Join(sn.Paths...)}
+		list := snapshotGroups[k]
+		list = append(list, sn)
+		snapshotGroups[k] = list
+	}
+
+	policy := restic.ExpirePolicy{
+		Last:    cmd.Last,
+		Hourly:  cmd.Hourly,
+		Daily:   cmd.Daily,
+		Weekly:  cmd.Weekly,
+		Monthly: cmd.Monthly,
+		Yearly:  cmd.Yearly,
+	}
+
+	for key, snapshotGroup := range snapshotGroups {
+		cmd.global.Printf("snapshots for host %v, directories %v:\n\n", key.Hostname, key.Dirs)
+		keep, remove := restic.ApplyPolicy(snapshotGroup, policy)
+
+		cmd.global.Printf("keep %d snapshots:\n", len(keep))
+		printSnapshots(cmd.global.stdout, keep)
+		cmd.global.Printf("\n")
+
+		cmd.global.Printf("remove %d snapshots:\n", len(remove))
+		printSnapshots(cmd.global.stdout, remove)
+		cmd.global.Printf("\n")
+
+		if !cmd.DryRun {
+			for _, sn := range remove {
+				err = repo.Backend().Remove(backend.Snapshot, sn.ID().String())
+				if err != nil {
+					return err
+				}
+			}
+		}
+	}
+
+	return nil
+}