better type checking

6 files changed, 295 insertions, 124 deletions

diff --git a/fi-filefilter/main.go b/fi-filefilter/main.go
index ae992ba..6731c1e 100644
--- a/fi-filefilter/main.go
+++ b/fi-filefilter/main.go
@@ -26,6 +26,8 @@ import (
 
 	"git.lukeshu.com/go/libfastimport"
 	"github.com/pkg/errors"
+
+	"git.parabola.nu/~lukeshu/fastimport-go-utils/fiutil"
 )
 
 func usage(w io.Writer) {
@@ -48,138 +50,113 @@ func main() {
 	frontend := libfastimport.NewFrontend(os.Stdin, os.Stdin, nil)
 	backend := libfastimport.NewBackend(os.Stdout, os.Stdout, nil)
 
-	if err := filefilter(backend, frontend, re); err != nil {
+	filter := &FileFilter{
+		backend: backend,
+		re:      re,
+		beg:     time.Now(),
+	}
+
+	if err := fiutil.RunHandler(frontend, filter); 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 (%d => %d files) (%.2f commit/s)\r",
-			commits, filesIn, filesOut,
-			float64(commits)/time.Since(beg).Seconds())
+type FileFilter struct {
+	backend *libfastimport.Backend
+	re      *regexp.Regexp
+
+	// statistics
+	commits  int
+	filesIn  int
+	filesOut int
+	beg      time.Time
+}
+
+// file commands ///////////////////////////////////////////////////////////////
+func (h *FileFilter) FileModify(cmd libfastimport.FileModify) error {
+	h.filesIn++
+	if !h.re.MatchString(string(cmd.Path)) {
+		return nil
 	}
+	h.filesOut++
+	return h.backend.Do(cmd)
+}
+func (h *FileFilter) FileModifyInline(cmd libfastimport.FileModifyInline) error {
+	h.filesIn++
+	if !h.re.MatchString(string(cmd.Path)) {
+		return nil
+	}
+	h.filesOut++
+	return h.backend.Do(cmd)
+}
+func (h *FileFilter) FileDelete(cmd libfastimport.FileDelete) error {
+	h.filesIn++
+	if !h.re.MatchString(string(cmd.Path)) {
+		return nil
+	}
+	h.filesOut++
+	return h.backend.Do(cmd)
+}
+func (h *FileFilter) FileDeleteAll(cmd libfastimport.FileDeleteAll) error {
+	return h.backend.Do(cmd)
+}
+func (h *FileFilter) FileCopy(cmd libfastimport.FileCopy) error {
+	return errors.New("unexpected \"filecopy\" command: this filter requires --full-tree")
+}
+func (h *FileFilter) FileRename(cmd libfastimport.FileRename) error {
+	return errors.New("unexpected \"filerename\" command: this filter requires --full-tree")
+}
 
-	for {
-		cmd, err := frontend.ReadCmd()
-		if err != nil {
-			if err == io.EOF {
-				break
-			}
-			return err
-		}
+// statistics //////////////////////////////////////////////////////////////////
+func (h *FileFilter) CmdCommitEnd(cmd libfastimport.CmdCommitEnd) error {
+	h.commits++
+	fmt.Fprintf(os.Stderr,
+		"%d commits (%d => %d files) (%.2f commit/s)\r",
+		h.commits, h.filesIn, h.filesOut,
+		float64(h.commits)/time.Since(h.beg).Seconds())
+	return nil
+}
+
+// note commands ///////////////////////////////////////////////////////////////
+func (h *FileFilter) NoteModify(cmd libfastimport.NoteModify) error {
+	return h.backend.Do(cmd)
+}
+func (h *FileFilter) NoteModifyInline(cmd libfastimport.NoteModifyInline) error {
+	return h.backend.Do(cmd)
+}
+
+// other commands //////////////////////////////////////////////////////////////
+func (h *FileFilter) CmdBlob(cmd libfastimport.CmdBlob) error             { return h.backend.Do(cmd) }
+func (h *FileFilter) CmdCheckpoint(cmd libfastimport.CmdCheckpoint) error { return h.backend.Do(cmd) }
+func (h *FileFilter) CmdComment(cmd libfastimport.CmdComment) error       { return h.backend.Do(cmd) }
+func (h *FileFilter) CmdCommit(cmd libfastimport.CmdCommit) error         { return h.backend.Do(cmd) }
+func (h *FileFilter) CmdDone(cmd libfastimport.CmdDone) error             { return h.backend.Do(cmd) }
+func (h *FileFilter) CmdOption(cmd libfastimport.CmdOption) error         { return h.backend.Do(cmd) }
+func (h *FileFilter) CmdProgress(cmd libfastimport.CmdProgress) error     { return h.backend.Do(cmd) }
+func (h *FileFilter) CmdReset(cmd libfastimport.CmdReset) error           { return h.backend.Do(cmd) }
+func (h *FileFilter) CmdTag(cmd libfastimport.CmdTag) error               { return h.backend.Do(cmd) }
+
+func (h *FileFilter) CmdCatBlob(cmd libfastimport.CmdCatBlob) (sha1 string, data string, err error) {
+	return h.backend.CatBlob(cmd)
+}
+func (h *FileFilter) CmdGetMark(cmd libfastimport.CmdGetMark) (sha1 string, err error) {
+	return h.backend.GetMark(cmd)
+}
+func (h *FileFilter) CmdLs(cmd libfastimport.CmdLs) (mode libfastimport.Mode, dataref string, path libfastimport.Path, err error) {
+	return h.backend.Ls(cmd)
+}
 
-		switch cmdt := cmd.(type) {
-
-			// commit //////////////////////////////////////////////
-		case libfastimport.CmdCommit:
-			if err := backend.Do(cmd); err != nil {
-				return err
-			}
-		case libfastimport.CmdCommitEnd:
-			commits++
-			status()
-
-			// file commands ///////////////////////////////////////
-		case libfastimport.FileModify:
-			filesIn++
-			if re.MatchString(string(cmdt.Path)) {
-				filesOut++
-				if err := backend.Do(cmd); err != nil {
-					return err
-				}
-			}
-		case libfastimport.FileModifyInline:
-			filesIn++
-			if re.MatchString(string(cmdt.Path)) {
-				filesOut++
-				if err := backend.Do(cmd); err != nil {
-					return err
-				}
-			}
-		case libfastimport.FileDelete:
-			filesIn++
-			if re.MatchString(string(cmdt.Path)) {
-				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:
-			return errors.New("unexpected \"filecopy\" command: this filter requires --full-tree")
-		case libfastimport.FileRename:
-			return errors.New("unexpected \"filerename\" command: this filter requires --full-tree")
-
-			// note commands ///////////////////////////////////////
-		case libfastimport.NoteModify, libfastimport.NoteModifyInline:
-			if err := backend.Do(cmd); err != nil {
-				return err
-			}
-
-			// regular commands ////////////////////////////////////
-		case libfastimport.CmdBlob, libfastimport.CmdCheckpoint, libfastimport.CmdComment, libfastimport.CmdDone, libfastimport.CmdProgress, libfastimport.CmdReset, libfastimport.CmdTag:
-			if err := backend.Do(cmd); err != nil {
-				return err
-			}
-
-			// special commands ////////////////////////////////////
-		case 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
-				}
-			default:
-				return errors.Errorf("unknown feature %q", cmdt.Feature)
-			}
-		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:
-			return errors.Errorf("unexpected command: %[1]T(%#[1]v)", cmd)
+func (h *FileFilter) CmdFeature(cmd libfastimport.CmdFeature) error {
+	switch cmd.Feature {
+	case "date-format":
+		if cmd.Argument != "raw" {
+			return errors.Errorf("date-format=%q: only supports the %q format", cmd.Argument, "raw")
 		}
+		return h.backend.Do(cmd)
+	case "export-marks", "relative-marks", "no-relative-marks", "force", "import-marks", "import-marks-if-exists", "get-mark", "cat-blob", "ls", "notes", "done":
+		return h.backend.Do(cmd)
+	default:
+		return errors.Errorf("unknown feature %q", cmd.Feature)
 	}
-	return nil
 }
diff --git a/fiutil/.gitignore b/fiutil/.gitignore
new file mode 100644
index 0000000..37724f0
--- /dev/null
+++ b/fiutil/.gitignore
@@ -0,0 +1 @@
+/handler.go
diff --git a/fiutil/Makefile b/fiutil/Makefile
new file mode 100644
index 0000000..c74bd8b
--- /dev/null
+++ b/fiutil/Makefile
@@ -0,0 +1,40 @@
+# Copyright 2015-2017, 2019  Luke Shumaker <lukeshu@parabola.nu>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# 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/>.
+
+# header
+ifneq ($(topsrcdir),)
+include $(topsrcdir)/build-aux/Makefile.head.mk
+else
+srcdir = .
+.DEFAULT_GOAL = files.generate
+endif
+
+# body
+
+files.src.gen += handler.go
+
+$(srcdir)/%.go: $(srcdir)/%.go.gen
+	cd $(@D) && ./$(^F) > $(@F)
+
+# footer
+ifneq ($(topsrcdir),)
+include $(topsrcdir)/build-aux/Makefile.tail.mk
+else
+files.generate: $(files.src.gen)
+maintainer-clean:
+	rm -f -- $(files.src.gen) $(files.src.int)
+.PHONY: files.generate maintainer-clean
+.DELETE_ON_ERROR:
+endif
diff --git a/fiutil/cli.go b/fiutil/cli.go
new file mode 100644
index 0000000..649aee4
--- /dev/null
+++ b/fiutil/cli.go
@@ -0,0 +1,27 @@
+// Copyright 2019  Luke Shumaker <lukeshu@parabola.nu>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// 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/>.
+
+package fiutil
+
+import (
+	"fmt"
+	"os"
+)
+
+func ErrUsage(msg string) {
+	fmt.Fprintln(os.Stderr, "%s: %s\n", os.Args[0], msg)
+	fmt.Fprintf(os.Stderr, "Try '%s --help' for more information\n", os.Args[0])
+	os.Exit(2)
+}
diff --git a/fiutil/doc.go b/fiutil/doc.go
new file mode 100644
index 0000000..4d6d5f9
--- /dev/null
+++ b/fiutil/doc.go
@@ -0,0 +1,20 @@
+// Copyright 2019  Luke Shumaker <lukeshu@parabola.nu>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// 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/>.
+
+//go:generate make
+
+// Package fiutil provides utilities for implementing fast-import
+// filters on top of git.lukeshu.com/go/libfastimport.
+package fiutil
diff --git a/fiutil/handler.go.gen b/fiutil/handler.go.gen
new file mode 100755
index 0000000..9f7d054
--- /dev/null
+++ b/fiutil/handler.go.gen
@@ -0,0 +1,106 @@
+#!/usr/bin/env bash
+# Copyright 2019  Luke Shumaker <lukeshu@parabola.nu>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# 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/>.
+
+cmds=(
+	CmdBlob
+	#CmdCatBlob
+	CmdCheckpoint
+	CmdComment
+	CmdCommit
+	CmdCommitEnd
+	CmdDone
+	CmdFeature
+	#CmdGetMark
+	#CmdLs
+	CmdOption
+	CmdProgress
+	CmdReset
+	CmdTag
+	FileCopy
+	FileDelete
+	FileDeleteAll
+	FileModify
+	FileModifyInline
+	FileRename
+	NoteModify
+	NoteModifyInline
+)
+
+{
+	cat <<-EOT
+	//$(printf ' %q' "$0" "$@")
+	// Code generated by the above command; DO NOT EDIT.
+
+	package fiutil
+	
+	import (
+		"io"
+			
+		"git.lukeshu.com/go/libfastimport"
+		"github.com/pkg/errors"
+	)
+	
+	type Handler interface{
+		$(for cmd in "${cmds[@]}"; do
+			echo "$cmd(libfastimport.$cmd) error"
+		done)
+		CmdCatBlob(libfastimport.CmdCatBlob) (sha1 string, data string, err error)
+		CmdGetMark(libfastimport.CmdGetMark) (sha1 string, err error)
+		CmdLs(libfastimport.CmdLs) (mode libfastimport.Mode, dataref string, path libfastimport.Path, err error)
+	}
+	
+	func RunHandler(reader *libfastimport.Frontend, handler Handler) error {
+		for {
+			cmd, err := reader.ReadCmd()
+			if err != nil {
+				if err == io.EOF {
+					return nil
+				}
+				return err
+			}
+	
+			switch  cmdt := cmd.(type) {
+				$(for cmd in "${cmds[@]}"; do
+					echo "case libfastimport.$cmd:"
+					echo "    if err := handler.$cmd(cmdt); err != nil {"
+					echo "        return err"
+					echo "    }"
+				done)
+			case libfastimport.CmdCatBlob:
+				sha1, data, err := handler.CmdCatBlob(cmdt)
+				if err != nil {
+					return err
+				}
+				return reader.RespondCatBlob(sha1, data)
+			case libfastimport.CmdGetMark:
+				sha1, err := handler.CmdGetMark(cmdt)
+				if err != nil {
+					return err
+				}
+				return reader.RespondGetMark(sha1)
+			case libfastimport.CmdLs:
+				mode, dataref, path, err := handler.CmdLs(cmdt)
+				if err != nil {
+					return err
+				}
+				return reader.RespondLs(mode, dataref, path)
+			default:
+				return errors.Errorf("unexpected command object: %[1]T(%#[1]v)", cmd)
+			}
+		}
+	}
+	EOT
+} | gofmt