vendor: add "go-grpc-middleware/util/backoffutils"

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>

Gopkg.lock

@@ -100,6 +100,12 @@
   packages = ["."]
   revision = "4201258b820c74ac8e6922fc9e6b52f71fe46f8d"
 
+[[projects]]
+  name = "github.com/grpc-ecosystem/go-grpc-middleware"
+  packages = ["util/backoffutils"]
+  revision = "c250d6563d4d4c20252cd865923440e829844f4e"
+  version = "v1.0.0"
+
 [[projects]]
   name = "github.com/grpc-ecosystem/go-grpc-prometheus"
   packages = ["."]
@@ -353,7 +359,6 @@
     "peer",
     "resolver",
     "resolver/dns",
-    "resolver/manual",
     "resolver/passthrough",
     "stats",
     "status",
@@ -378,6 +383,6 @@
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "9b6e97c6524385aecaa477af059f4f6555b3609d4a283ecf27ac2ad4fbe08f06"
+  inputs-digest = "40c72e54abdb7d6c044f2f5fabb8fc7ac2eadcab047cc22b28d26b7b145b5e1b"
   solver-name = "gps-cdcl"
   solver-version = 1

vendor/github.com/grpc-ecosystem/go-grpc-middleware/LICENSE

@@ -0,0 +1,201 @@
+                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
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+       http://www.apache.org/licenses/LICENSE-2.0
+
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+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go

@@ -0,0 +1,183 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+// gRPC Server Interceptor chaining middleware.
+
+package grpc_middleware
+
+import (
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+)
+
+// ChainUnaryServer creates a single interceptor out of a chain of many interceptors.
+//
+// Execution is done in left-to-right order, including passing of context.
+// For example ChainUnaryServer(one, two, three) will execute one before two before three, and three
+// will see context changes of one and two.
+func ChainUnaryServer(interceptors ...grpc.UnaryServerInterceptor) grpc.UnaryServerInterceptor {
+	n := len(interceptors)
+
+	if n > 1 {
+		lastI := n - 1
+		return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+			var (
+				chainHandler grpc.UnaryHandler
+				curI         int
+			)
+
+			chainHandler = func(currentCtx context.Context, currentReq interface{}) (interface{}, error) {
+				if curI == lastI {
+					return handler(currentCtx, currentReq)
+				}
+				curI++
+				resp, err := interceptors[curI](currentCtx, currentReq, info, chainHandler)
+				curI--
+				return resp, err
+			}
+
+			return interceptors[0](ctx, req, info, chainHandler)
+		}
+	}
+
+	if n == 1 {
+		return interceptors[0]
+	}
+
+	// n == 0; Dummy interceptor maintained for backward compatibility to avoid returning nil.
+	return func(ctx context.Context, req interface{}, _ *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		return handler(ctx, req)
+	}
+}
+
+// ChainStreamServer creates a single interceptor out of a chain of many interceptors.
+//
+// Execution is done in left-to-right order, including passing of context.
+// For example ChainUnaryServer(one, two, three) will execute one before two before three.
+// If you want to pass context between interceptors, use WrapServerStream.
+func ChainStreamServer(interceptors ...grpc.StreamServerInterceptor) grpc.StreamServerInterceptor {
+	n := len(interceptors)
+
+	if n > 1 {
+		lastI := n - 1
+		return func(srv interface{}, stream grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+			var (
+				chainHandler grpc.StreamHandler
+				curI         int
+			)
+
+			chainHandler = func(currentSrv interface{}, currentStream grpc.ServerStream) error {
+				if curI == lastI {
+					return handler(currentSrv, currentStream)
+				}
+				curI++
+				err := interceptors[curI](currentSrv, currentStream, info, chainHandler)
+				curI--
+				return err
+			}
+
+			return interceptors[0](srv, stream, info, chainHandler)
+		}
+	}
+
+	if n == 1 {
+		return interceptors[0]
+	}
+
+	// n == 0; Dummy interceptor maintained for backward compatibility to avoid returning nil.
+	return func(srv interface{}, stream grpc.ServerStream, _ *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		return handler(srv, stream)
+	}
+}
+
+// ChainUnaryClient creates a single interceptor out of a chain of many interceptors.
+//
+// Execution is done in left-to-right order, including passing of context.
+// For example ChainUnaryClient(one, two, three) will execute one before two before three.
+func ChainUnaryClient(interceptors ...grpc.UnaryClientInterceptor) grpc.UnaryClientInterceptor {
+	n := len(interceptors)
+
+	if n > 1 {
+		lastI := n - 1
+		return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+			var (
+				chainHandler grpc.UnaryInvoker
+				curI         int
+			)
+
+			chainHandler = func(currentCtx context.Context, currentMethod string, currentReq, currentRepl interface{}, currentConn *grpc.ClientConn, currentOpts ...grpc.CallOption) error {
+				if curI == lastI {
+					return invoker(currentCtx, currentMethod, currentReq, currentRepl, currentConn, currentOpts...)
+				}
+				curI++
+				err := interceptors[curI](currentCtx, currentMethod, currentReq, currentRepl, currentConn, chainHandler, currentOpts...)
+				curI--
+				return err
+			}
+
+			return interceptors[0](ctx, method, req, reply, cc, chainHandler, opts...)
+		}
+	}
+
+	if n == 1 {
+		return interceptors[0]
+	}
+
+	// n == 0; Dummy interceptor maintained for backward compatibility to avoid returning nil.
+	return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+		return invoker(ctx, method, req, reply, cc, opts...)
+	}
+}
+
+// ChainStreamClient creates a single interceptor out of a chain of many interceptors.
+//
+// Execution is done in left-to-right order, including passing of context.
+// For example ChainStreamClient(one, two, three) will execute one before two before three.
+func ChainStreamClient(interceptors ...grpc.StreamClientInterceptor) grpc.StreamClientInterceptor {
+	n := len(interceptors)
+
+	if n > 1 {
+		lastI := n - 1
+		return func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+			var (
+				chainHandler grpc.Streamer
+				curI         int
+			)
+
+			chainHandler = func(currentCtx context.Context, currentDesc *grpc.StreamDesc, currentConn *grpc.ClientConn, currentMethod string, currentOpts ...grpc.CallOption) (grpc.ClientStream, error) {
+				if curI == lastI {
+					return streamer(currentCtx, currentDesc, currentConn, currentMethod, currentOpts...)
+				}
+				curI++
+				stream, err := interceptors[curI](currentCtx, currentDesc, currentConn, currentMethod, chainHandler, currentOpts...)
+				curI--
+				return stream, err
+			}
+
+			return interceptors[0](ctx, desc, cc, method, chainHandler, opts...)
+		}
+	}
+
+	if n == 1 {
+		return interceptors[0]
+	}
+
+	// n == 0; Dummy interceptor maintained for backward compatibility to avoid returning nil.
+	return func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+		return streamer(ctx, desc, cc, method, opts...)
+	}
+}
+
+// Chain creates a single interceptor out of a chain of many interceptors.
+//
+// WithUnaryServerChain is a grpc.Server config option that accepts multiple unary interceptors.
+// Basically syntactic sugar.
+func WithUnaryServerChain(interceptors ...grpc.UnaryServerInterceptor) grpc.ServerOption {
+	return grpc.UnaryInterceptor(ChainUnaryServer(interceptors...))
+}
+
+// WithStreamServerChain is a grpc.Server config option that accepts multiple stream interceptors.
+// Basically syntactic sugar.
+func WithStreamServerChain(interceptors ...grpc.StreamServerInterceptor) grpc.ServerOption {
+	return grpc.StreamInterceptor(ChainStreamServer(interceptors...))
+}

vendor/github.com/grpc-ecosystem/go-grpc-middleware/doc.go

@@ -0,0 +1,69 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+/*
+`grpc_middleware` is a collection of gRPC middleware packages: interceptors, helpers and tools.
+
+Middleware
+
+gRPC is a fantastic RPC middleware, which sees a lot of adoption in the Golang world. However, the
+upstream gRPC codebase is relatively bare bones.
+
+This package, and most of its child packages provides commonly needed middleware for gRPC:
+client-side interceptors for retires, server-side interceptors for input validation and auth,
+functions for chaining said interceptors, metadata convenience methods and more.
+
+Chaining
+
+By default, gRPC doesn't allow one to have more than one interceptor either on the client nor on
+the server side. `grpc_middleware` provides convenient chaining methods
+
+Simple way of turning a multiple interceptors into a single interceptor. Here's an example for
+server chaining:
+
+	myServer := grpc.NewServer(
+	    grpc.StreamInterceptor(grpc_middleware.ChainStreamServer(loggingStream, monitoringStream, authStream)),
+	    grpc.UnaryInterceptor(grpc_middleware.ChainUnaryServer(loggingUnary, monitoringUnary, authUnary),
+	)
+
+These interceptors will be executed from left to right: logging, monitoring and auth.
+
+Here's an example for client side chaining:
+
+	clientConn, err = grpc.Dial(
+	    address,
+	        grpc.WithUnaryInterceptor(grpc_middleware.ChainUnaryClient(monitoringClientUnary, retryUnary)),
+	        grpc.WithStreamInterceptor(grpc_middleware.ChainStreamClient(monitoringClientStream, retryStream)),
+	)
+	client = pb_testproto.NewTestServiceClient(clientConn)
+	resp, err := client.PingEmpty(s.ctx, &myservice.Request{Msg: "hello"})
+
+These interceptors will be executed from left to right: monitoring and then retry logic.
+
+The retry interceptor will call every interceptor that follows it whenever when a retry happens.
+
+Writing Your Own
+
+Implementing your own interceptor is pretty trivial: there are interfaces for that. But the interesting
+bit exposing common data to handlers (and other middleware), similarly to HTTP Middleware design.
+For example, you may want to pass the identity of the caller from the auth interceptor all the way
+to the handling function.
+
+For example, a client side interceptor example for auth looks like:
+
+	func FakeAuthUnaryInterceptor(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+	   newCtx := context.WithValue(ctx, "user_id", "john@example.com")
+	   return handler(newCtx, req)
+	}
+
+Unfortunately, it's not as easy for streaming RPCs. These have the `context.Context` embedded within
+the `grpc.ServerStream` object. To pass values through context, a wrapper (`WrappedServerStream`) is
+needed. For example:
+
+	func FakeAuthStreamingInterceptor(srv interface{}, stream grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+	   newStream := grpc_middleware.WrapServerStream(stream)
+	   newStream.WrappedContext = context.WithValue(ctx, "user_id", "john@example.com")
+	   return handler(srv, stream)
+	}
+*/
+package grpc_middleware

vendor/github.com/grpc-ecosystem/go-grpc-middleware/util/backoffutils/backoff.go

@@ -0,0 +1,23 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+/*
+Backoff Helper Utilities
+
+Implements common backoff features.
+*/
+package backoffutils
+
+import (
+	"math/rand"
+	"time"
+)
+
+// JitterUp adds random jitter to the duration.
+//
+// This adds or substracts time from the duration within a given jitter fraction.
+// For example for 10s and jitter 0.1, it will returna  time within [9s, 11s])
+func JitterUp(duration time.Duration, jitter float64) time.Duration {
+	multiplier := jitter * (rand.Float64()*2 - 1)
+	return time.Duration(float64(duration) * (1 + multiplier))
+}

vendor/github.com/grpc-ecosystem/go-grpc-middleware/wrappers.go

@@ -0,0 +1,29 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_middleware
+
+import (
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+)
+
+// WrappedServerStream is a thin wrapper around grpc.ServerStream that allows modifying context.
+type WrappedServerStream struct {
+	grpc.ServerStream
+	// WrappedContext is the wrapper's own Context. You can assign it.
+	WrappedContext context.Context
+}
+
+// Context returns the wrapper's WrappedContext, overwriting the nested grpc.ServerStream.Context()
+func (w *WrappedServerStream) Context() context.Context {
+	return w.WrappedContext
+}
+
+// WrapServerStream returns a ServerStream that has the ability to overwrite context.
+func WrapServerStream(stream grpc.ServerStream) *WrappedServerStream {
+	if existing, ok := stream.(*WrappedServerStream); ok {
+		return existing
+	}
+	return &WrappedServerStream{ServerStream: stream, WrappedContext: stream.Context()}
+}

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()
+}