cli: wip: Rethink the "scan" CLI commands

3 files changed, 17 insertions, 107 deletions

diff --git a/cmd/btrfs-rec/inspect_dumpsums.go b/cmd/btrfs-rec/inspect_dumpsums.go
deleted file mode 100644
index 28ae7ef..0000000
--- a/cmd/btrfs-rec/inspect_dumpsums.go
+++ /dev/null
@@ -1,35 +0,0 @@
-// Copyright (C) 2022  Luke Shumaker <lukeshu@lukeshu.com>
-//
-// SPDX-License-Identifier: GPL-2.0-or-later
-
-package main
-
-import (
-	"os"
-
-	"github.com/datawire/dlib/dlog"
-	"github.com/datawire/ocibuild/pkg/cliutil"
-	"github.com/spf13/cobra"
-
-	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs"
-	"git.lukeshu.com/btrfs-progs-ng/lib/btrfsprogs/btrfsinspect/rebuildmappings"
-)
-
-func init() {
-	inspectors = append(inspectors, subcommand{
-		Command: cobra.Command{
-			Use:   "dump-sums",
-			Short: "Dump a buncha checksums as JSON",
-			Args:  cliutil.WrapPositionalArgs(cobra.NoArgs),
-		},
-		RunE: func(fs *btrfs.FS, cmd *cobra.Command, _ []string) error {
-			ctx := cmd.Context()
-			sums, err := rebuildmappings.SumEverything(ctx, fs)
-			if err != nil {
-				return err
-			}
-			dlog.Info(ctx, "Writing sums as gob to stdout...")
-			return rebuildmappings.WriteAllSums(os.Stdout, sums)
-		},
-	})
-}
diff --git a/cmd/btrfs-rec/inspect_scanfornodes.go b/cmd/btrfs-rec/inspect_scandevices.go
index 13f7760..f5caadb 100644
--- a/cmd/btrfs-rec/inspect_scanfornodes.go
+++ b/cmd/btrfs-rec/inspect_scandevices.go
@@ -5,11 +5,12 @@
 package main
 
 import (
+	"bufio"
 	"context"
-	"encoding/json"
 	"os"
 	"sync"
 
+	"git.lukeshu.com/go/lowmemjson"
 	"github.com/datawire/dlib/dgroup"
 	"github.com/datawire/dlib/dlog"
 	"github.com/datawire/ocibuild/pkg/cliutil"
@@ -23,23 +24,15 @@ import (
 func init() {
 	inspectors = append(inspectors, subcommand{
 		Command: cobra.Command{
-			Use:   "scan-for-nodes",
-			Short: "Scan devices for (potentially lost) nodes",
-			Long: "" +
-				"The found information is printed as JSON on stdout, and can\n" +
-				"be read by `btrfs-rec inspect rebuild-mappings`.\n" +
-				"\n" +
-				"This information is mostly useful for rebuilding a broken\n" +
-				"chunk/dev-extent/blockgroup trees, but can also have some\n" +
-				"minimal utility in repairing other trees.\n" +
-				"\n" +
-				"This is very similar the initial scan done by\n" +
-				"`btrfs rescue chunk-recover`.  Like `btrfs rescue chunk-recover`,\n" +
-				"this is likely probably slow because it reads the entirety of\n" +
-				"each device.",
+			Use:  "scandevices",
 			Args: cliutil.WrapPositionalArgs(cobra.NoArgs),
 		},
-		RunE: func(fs *btrfs.FS, cmd *cobra.Command, _ []string) error {
+		RunE: func(fs *btrfs.FS, cmd *cobra.Command, _ []string) (err error) {
+			maybeSetErr := func(_err error) {
+				if err == nil && _err != nil {
+					err = _err
+				}
+			}
 			ctx := cmd.Context()
 
 			var resultsMu sync.Mutex
@@ -66,7 +59,14 @@ func init() {
 			}
 
 			dlog.Info(ctx, "Writing scan results to stdout...")
-			return json.NewEncoder(os.Stdout).Encode(results)
+			buffer := bufio.NewWriter(os.Stdout)
+			defer func() {
+				maybeSetErr(buffer.Flush())
+			}()
+			return lowmemjson.Encode(&lowmemjson.ReEncoder{
+				Out:    buffer,
+				Indent: "\t",
+			}, results)
 		},
 	})
 }
diff --git a/cmd/btrfs-rec/inspect_scanforextents.go b/cmd/btrfs-rec/inspect_scanforextents.go
deleted file mode 100644
index 9b5ada4..0000000
--- a/cmd/btrfs-rec/inspect_scanforextents.go
+++ /dev/null
@@ -1,55 +0,0 @@
-// Copyright (C) 2022  Luke Shumaker <lukeshu@lukeshu.com>
-//
-// SPDX-License-Identifier: GPL-2.0-or-later
-
-package main
-
-import (
-	"os"
-	"runtime"
-
-	"github.com/datawire/dlib/dlog"
-	"github.com/datawire/ocibuild/pkg/cliutil"
-	"github.com/spf13/cobra"
-
-	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs"
-	"git.lukeshu.com/btrfs-progs-ng/lib/btrfsprogs/btrfsinspect/rebuildmappings"
-)
-
-func init() {
-	inspectors = append(inspectors, subcommand{
-		Command: cobra.Command{
-			Use:  "scan-for-extents NODESCAN.json DUMPSUMS.gob",
-			Args: cliutil.WrapPositionalArgs(cobra.ExactArgs(2)),
-		},
-		RunE: func(fs *btrfs.FS, cmd *cobra.Command, args []string) error {
-			ctx := cmd.Context()
-
-			dlog.Infof(ctx, "Reading %q...", args[0])
-			bgs, err := rebuildmappings.ReadNodeScanResults(fs, args[0])
-			if err != nil {
-				return err
-			}
-			runtime.GC()
-			dlog.Infof(ctx, "... done reading %q", args[0])
-
-			dlog.Infof(ctx, "Reading %q...", args[1])
-			sums, err := rebuildmappings.ReadAllSums(args[1])
-			if err != nil {
-				return err
-			}
-			dlog.Infof(ctx, "... done reading %q", args[1])
-
-			if err := rebuildmappings.ScanForExtents(ctx, fs, bgs, sums); err != nil {
-				return err
-			}
-
-			dlog.Infof(ctx, "Writing reconstructed mappings to stdout...")
-			if err := writeMappingsJSON(os.Stdout, fs); err != nil {
-				return err
-			}
-
-			return nil
-		},
-	})
-}