Update libkv dependency

vendor/google.golang.org/genproto/regen.go

@@ -0,0 +1,123 @@
+// Copyright 2016 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build ignore
+
+// Regen.go regenerates the genproto repository.
+//
+// Regen.go recursively walks through each directory named by given arguments,
+// looking for all .proto files. (Symlinks are not followed.)
+// If the pkg_prefix flag is not an empty string,
+// any proto file without `go_package` option
+// or whose option does not begin with the prefix is ignored.
+// Protoc is executed on remaining files,
+// one invocation per set of files declaring the same Go package.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+var goPkgOptRe = regexp.MustCompile(`(?m)^option go_package = (.*);`)
+
+func usage() {
+	fmt.Fprintln(os.Stderr, `usage: go run regen.go -go_out=path/to/output [-pkg_prefix=pkg/prefix] roots...
+
+Most users will not need to run this file directly.
+To regenerate this repository, run regen.sh instead.`)
+	flag.PrintDefaults()
+}
+
+func main() {
+	goOutDir := flag.String("go_out", "", "go_out argument to pass to protoc-gen-go")
+	pkgPrefix := flag.String("pkg_prefix", "", "only include proto files with go_package starting with this prefix")
+	flag.Usage = usage
+	flag.Parse()
+
+	if *goOutDir == "" {
+		log.Fatal("need go_out flag")
+	}
+
+	pkgFiles := make(map[string][]string)
+	walkFn := func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if !info.Mode().IsRegular() || !strings.HasSuffix(path, ".proto") {
+			return nil
+		}
+		pkg, err := goPkg(path)
+		if err != nil {
+			return err
+		}
+		pkgFiles[pkg] = append(pkgFiles[pkg], path)
+		return nil
+	}
+	for _, root := range flag.Args() {
+		if err := filepath.Walk(root, walkFn); err != nil {
+			log.Fatal(err)
+		}
+	}
+	for pkg, fnames := range pkgFiles {
+		if !strings.HasPrefix(pkg, *pkgPrefix) {
+			continue
+		}
+		if out, err := protoc(*goOutDir, flag.Args(), fnames); err != nil {
+			log.Fatalf("error executing protoc: %s\n%s", err, out)
+		}
+	}
+}
+
+// goPkg reports the import path declared in the given file's
+// `go_package` option. If the option is missing, goPkg returns empty string.
+func goPkg(fname string) (string, error) {
+	content, err := ioutil.ReadFile(fname)
+	if err != nil {
+		return "", err
+	}
+
+	var pkgName string
+	if match := goPkgOptRe.FindSubmatch(content); len(match) > 0 {
+		pn, err := strconv.Unquote(string(match[1]))
+		if err != nil {
+			return "", err
+		}
+		pkgName = pn
+	}
+	if p := strings.IndexRune(pkgName, ';'); p > 0 {
+		pkgName = pkgName[:p]
+	}
+	return pkgName, nil
+}
+
+// protoc executes the "protoc" command on files named in fnames,
+// passing go_out and include flags specified in goOut and includes respectively.
+// protoc returns combined output from stdout and stderr.
+func protoc(goOut string, includes, fnames []string) ([]byte, error) {
+	args := []string{"--go_out=plugins=grpc:" + goOut}
+	for _, inc := range includes {
+		args = append(args, "-I", inc)
+	}
+	args = append(args, fnames...)
+	return exec.Command("protoc", args...).CombinedOutput()
+}