fi-filefilter: clean up

 - handle all commands robustly
 - error checking
 - don't worry about pruning empty commits, fi-prune-empty exists now

1 files changed, 101 insertions, 53 deletions

diff --git a/fi-filefilter/main.go b/fi-filefilter/main.go
index 645b8c4..44ab5fe 100644
--- a/fi-filefilter/main.go
+++ b/fi-filefilter/main.go
@@ -13,6 +13,8 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+// Command fi-filefilter prunes a fast-import stream, removing
+// filenames that do not match a regexp.
 package main
 
 import (
@@ -20,106 +22,152 @@ import (
 	"io"
 	"os"
 	"regexp"
-	"strings"
 	"time"
 
 	"git.lukeshu.com/go/libfastimport"
+	"github.com/pkg/errors"
 )
 
-func abort(err error) {
-	fmt.Fprintln(os.Stderr, "Error:", err)
-	os.Exit(1)
+func usage(w io.Writer) {
+	fmt.Fprintf(w, "Usage: git fast-export --full-tree | %s REGEXP | git fast-import\n", os.Args[0])
+	fmt.Fprintf(w, "Prunes a fast-import stream, removing filenames that do not match a regexp\n")
 }
 
-var commit *libfastimport.CmdCommit
-
-var (
-	frontend = libfastimport.NewFrontend(os.Stdin, nil, nil)
-	backend  = libfastimport.NewBackend(os.Stdout, nil, nil)
-)
-
-func ensureCommit() {
-	if commit == nil {
-		return
+func main() {
+	if len(os.Args) != 2 {
+		usage(os.Stderr)
+		os.Exit(2)
 	}
-	backend.Do(*commit)
-	commit = nil
-}
 
-func main() {
 	re, err := regexp.Compile(os.Args[1])
 	if err != nil {
-		abort(err)
+		fmt.Fprintf(os.Stderr, "%s: error: %v\n", os.Args[0], err)
+		os.Exit(2)
 	}
 
+	frontend := libfastimport.NewFrontend(os.Stdin, os.Stdin, nil)
+	backend := libfastimport.NewBackend(os.Stdout, os.Stdout, nil)
+
+	if err := filefilter(backend, frontend, re); err != nil {
+		fmt.Fprintf(os.Stderr, "%s: error: %v\n", os.Args[0], err)
+		os.Exit(1)
+	}
+}
+
+func filefilter(backend *libfastimport.Backend, frontend *libfastimport.Frontend, re *regexp.Regexp) error {
 	commits := 0
+	filesIn := 0
+	filesOut := 0
 	beg := time.Now()
 	status := func() {
 		fmt.Fprintf(os.Stderr,
-			"%d commits (%.2f commit/s)\r",
-			commits,
+			"%d commits (%d => %d files) (%.2f commit/s)\r",
+			commits, filesIn, filesOut,
 			float64(commits)/time.Since(beg).Seconds())
 	}
 
-	froms := map[string]string{}
 	for {
 		cmd, err := frontend.ReadCmd()
 		if err != nil {
 			if err == io.EOF {
 				break
 			}
-			abort(err)
+			return err
 		}
 
 		switch cmdt := cmd.(type) {
 
-		case libfastimport.CmdCommit:
-			commit = &cmdt
-			if strings.HasPrefix(commit.From, ":") {
-				if from, ok := froms[commit.From]; ok {
-					commit.From = from
-				}
-			}
-			for i, m := range commit.Merge {
-				if strings.HasPrefix(m, ":") {
-					if from, ok := froms[m]; ok {
-						commit.Merge[i] = from
-					}
-				}
-			}
-
+		// file commands
 		case libfastimport.FileModify:
+			filesIn++
 			if re.MatchString(string(cmdt.Path)) {
-				ensureCommit()
-				backend.Do(cmd)
+				filesOut++
+				if err := backend.Do(cmd); err != nil {
+					return err
+				}
 			}
 		case libfastimport.FileModifyInline:
+			filesIn++
 			if re.MatchString(string(cmdt.Path)) {
-				ensureCommit()
-				backend.Do(cmd)
+				filesOut++
+				if err := backend.Do(cmd); err != nil {
+					return err
+				}
 			}
 		case libfastimport.FileDelete:
+			filesIn++
 			if re.MatchString(string(cmdt.Path)) {
-				ensureCommit()
-				backend.Do(cmd)
+				filesOut++
+				if err := backend.Do(cmd); err != nil {
+					return err
+				}
+			}
+		case libfastimport.FileDeleteAll:
+			if err := backend.Do(cmd); err != nil {
+				return err
 			}
 		case libfastimport.FileCopy:
-			panic("copy")
+			return errors.New("unexpected \"filecopy\" command: this filter requires --full-tree")
 		case libfastimport.FileRename:
-			panic("rename")
+			return errors.New("unexpected \"filerename\" command: this filter requires --full-tree")
 
+			// statistics
 		case libfastimport.CmdCommitEnd:
-			if commit != nil {
-				if commit.Mark >= 0 {
-					froms[fmt.Sprintf(":%d", commit.Mark)] = commit.From
-				}
-				commit = nil
-			}
 			commits++
 			status()
 
+			// regular commands
+		case libfastimport.CmdBlob, libfastimport.CmdCheckpoint, libfastimport.CmdComment, libfastimport.CmdCommit, libfastimport.CmdDone, libfastimport.CmdReset, libfastimport.CmdTag:
+			if err := backend.Do(cmd); err != nil {
+				return err
+			}
+
+			// special commands
+		case libfastimport.CmdProgress, libfastimport.CmdOption:
+			if err := backend.Do(cmd); err != nil {
+				return err
+			}
+		case libfastimport.CmdFeature:
+			switch cmdt.Feature {
+			case "date-format":
+				if cmdt.Argument != "raw" {
+					return errors.Errorf("date-format=%q: only supports the %q format", cmdt.Argument, "raw")
+				}
+				if err := backend.Do(cmd); err != nil {
+					return err
+				}
+			case "export-marks", "relative-marks", "no-relative-marks", "force", "import-marks", "import-marks-if-exists", "get-mark", "cat-blob", "ls", "notes", "done":
+				if err := backend.Do(cmd); err != nil {
+					return err
+				}
+			}
+		case libfastimport.CmdCatBlob:
+			sha1, data, err := backend.CatBlob(cmdt)
+			if err != nil {
+				return err
+			}
+			if err := frontend.RespondCatBlob(sha1, data); err != nil {
+				return err
+			}
+		case libfastimport.CmdGetMark:
+			sha1, err := backend.GetMark(cmdt)
+			if err != nil {
+				return err
+			}
+			if err := frontend.RespondGetMark(sha1); err != nil {
+				return err
+			}
+		case libfastimport.CmdLs:
+			mode, dataref, path, err := backend.Ls(cmdt)
+			if err != nil {
+				return err
+			}
+			if err := frontend.RespondLs(mode, dataref, path); err != nil {
+				return err
+			}
 		default:
-			backend.Do(cmd)
+			panic("should not happen")
 		}
 	}
+	return nil
 }