gc: add option to stream errors

License: MIT
Signed-off-by: Kevin Atkinson <k@kevina.org>

core/commands/repo.go

@@ -40,6 +40,11 @@ var RepoCmd = &cmds.Command{
 	},
 }
 
+type GcResult struct {
+	Key   *cid.Cid
+	Error string `json:",omitempty"`
+}
+
 var repoGcCmd = &cmds.Command{
 	Helptext: cmds.HelpText{
 		Tagline: "Perform a garbage collection sweep on the repo.",
@@ -51,6 +56,7 @@ order to reclaim hard disk space.
 	},
 	Options: []cmds.Option{
 		cmds.BoolOption("quiet", "q", "Write minimal output.").Default(false),
+		cmds.BoolOption("stream-errors", "Stream errors.").Default(false),
 	},
 	Run: func(req cmds.Request, res cmds.Response) {
 		n, err := req.InvocContext().GetNode()
@@ -59,22 +65,41 @@ order to reclaim hard disk space.
 			return
 		}
 
+		streamErrors, _, _ := res.Request().Option("stream-errors").Bool()
+
 		gcOutChan := corerepo.GarbageCollectAsync(n, req.Context())
 
-		outChan := make(chan interface{}, len(gcOutChan))
+		outChan := make(chan interface{}, cap(gcOutChan))
 		res.SetOutput((<-chan interface{})(outChan))
 
 		go func() {
 			defer close(outChan)
-			err := corerepo.CollectResult(req.Context(), gcOutChan, func(k *cid.Cid) {
-				outChan <- &corerepo.KeyRemoved{k}
+			unreportedError := false
+			var lastErr error
+			if streamErrors {
+				for res := range gcOutChan {
+					if unreportedError {
+						outChan <- &GcResult{Error: lastErr.Error()}
+						unreportedError = false
+					}
+					if res.Error != nil {
+						lastErr = res.Error
+						unreportedError = true
+					} else {
+						outChan <- &GcResult{Key: res.KeyRemoved}
+					}
+				}
+			} else {
+				lastErr = corerepo.CollectResult(req.Context(), gcOutChan, func(k *cid.Cid) {
+					outChan <- &GcResult{Key: k}
 				})
-			if err != nil {
-				res.SetError(err, cmds.ErrNormal)
+			}
+			if lastErr != nil {
+				res.SetError(lastErr, cmds.ErrNormal)
 			}
 		}()
 	},
-	Type: corerepo.KeyRemoved{},
+	Type: GcResult{},
 	Marshalers: cmds.MarshalerMap{
 		cmds.Text: func(res cmds.Response) (io.Reader, error) {
 			outChan, ok := res.Output().(<-chan interface{})
@@ -87,26 +112,29 @@ order to reclaim hard disk space.
 				return nil, err
 			}
 
-			marshal := func(v interface{}) (io.Reader, error) {
-				obj, ok := v.(*corerepo.KeyRemoved)
+			for v := range outChan {
+				obj, ok := v.(*GcResult)
 				if !ok {
 					return nil, u.ErrCast()
 				}
 
-				buf := new(bytes.Buffer)
+				if obj.Error != "" {
+					fmt.Fprintf(res.Stderr(), "Error: %s\n", obj.Error)
+					continue
+				}
+
 				if quiet {
-					buf = bytes.NewBufferString(obj.Key.String() + "\n")
+					fmt.Fprintf(res.Stdout(), "%s\n", obj.Key.String())
 				} else {
-					buf = bytes.NewBufferString(fmt.Sprintf("removed %s\n", obj.Key))
+					fmt.Fprintf(res.Stdout(), "removed %s\n", obj.Key.String())
 				}
-				return buf, nil
 			}
 
-			return &cmds.ChannelMarshaler{
-				Channel:   outChan,
-				Marshaler: marshal,
-				Res:       res,
-			}, nil
+			if res.Error() != nil {
+				return nil, res.Error()
+			}
+
+			return nil, nil
 		},
 	},
 }

core/corerepo/gc.go

@@ -20,10 +20,6 @@ var log = logging.Logger("corerepo")
 
 var ErrMaxStorageExceeded = errors.New("Maximum storage limit exceeded. Maybe unpin some files?")
 
-type KeyRemoved struct {
-	Key *cid.Cid
-}
-
 type GC struct {
 	Node       *core.IpfsNode
 	Repo       repo.Repo

test/sharness/t0087-repo-robust-gc.sh

@@ -134,6 +134,13 @@ test_gc_robust_part2() {
 		grep -q "aborted" repo_gc_out
 	'
 
+	test_expect_success "'ipfs repo gc --stream-errors' should abort and report each error separately" '
+		test_must_fail ipfs repo gc --stream-errors 2>&1 | tee repo_gc_out &&
+		grep -q "Error: could not retrieve links for $LEAF1" repo_gc_out &&
+		grep -q "Error: could not retrieve links for $LEAF2" repo_gc_out &&
+		grep -q "Error: garbage collection aborted" repo_gc_out
+	'
+
 	test_expect_success "unpin 1MB file" '
 		ipfs pin rm $HASH2
 	'