diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/pattern.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/pattern.go
new file mode 100644
index 0000000..0905369
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/pattern.go
@@ -0,0 +1,262 @@
+package runtime
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/grpc-ecosystem/grpc-gateway/utilities"
+	"google.golang.org/grpc/grpclog"
+)
+
+var (
+	// ErrNotMatch indicates that the given HTTP request path does not match to the pattern.
+	ErrNotMatch = errors.New("not match to the path pattern")
+	// ErrInvalidPattern indicates that the given definition of Pattern is not valid.
+	ErrInvalidPattern = errors.New("invalid pattern")
+)
+
+type op struct {
+	code    utilities.OpCode
+	operand int
+}
+
+// Pattern is a template pattern of http request paths defined in github.com/googleapis/googleapis/google/api/http.proto.
+type Pattern struct {
+	// ops is a list of operations
+	ops []op
+	// pool is a constant pool indexed by the operands or vars.
+	pool []string
+	// vars is a list of variables names to be bound by this pattern
+	vars []string
+	// stacksize is the max depth of the stack
+	stacksize int
+	// tailLen is the length of the fixed-size segments after a deep wildcard
+	tailLen int
+	// verb is the VERB part of the path pattern. It is empty if the pattern does not have VERB part.
+	verb string
+	// assumeColonVerb indicates whether a path suffix after a final
+	// colon may only be interpreted as a verb.
+	assumeColonVerb bool
+}
+
+type patternOptions struct {
+	assumeColonVerb bool
+}
+
+// PatternOpt is an option for creating Patterns.
+type PatternOpt func(*patternOptions)
+
+// NewPattern returns a new Pattern from the given definition values.
+// "ops" is a sequence of op codes. "pool" is a constant pool.
+// "verb" is the verb part of the pattern. It is empty if the pattern does not have the part.
+// "version" must be 1 for now.
+// It returns an error if the given definition is invalid.
+func NewPattern(version int, ops []int, pool []string, verb string, opts ...PatternOpt) (Pattern, error) {
+	options := patternOptions{
+		assumeColonVerb: true,
+	}
+	for _, o := range opts {
+		o(&options)
+	}
+
+	if version != 1 {
+		grpclog.Infof("unsupported version: %d", version)
+		return Pattern{}, ErrInvalidPattern
+	}
+
+	l := len(ops)
+	if l%2 != 0 {
+		grpclog.Infof("odd number of ops codes: %d", l)
+		return Pattern{}, ErrInvalidPattern
+	}
+
+	var (
+		typedOps        []op
+		stack, maxstack int
+		tailLen         int
+		pushMSeen       bool
+		vars            []string
+	)
+	for i := 0; i < l; i += 2 {
+		op := op{code: utilities.OpCode(ops[i]), operand: ops[i+1]}
+		switch op.code {
+		case utilities.OpNop:
+			continue
+		case utilities.OpPush:
+			if pushMSeen {
+				tailLen++
+			}
+			stack++
+		case utilities.OpPushM:
+			if pushMSeen {
+				grpclog.Infof("pushM appears twice")
+				return Pattern{}, ErrInvalidPattern
+			}
+			pushMSeen = true
+			stack++
+		case utilities.OpLitPush:
+			if op.operand < 0 || len(pool) <= op.operand {
+				grpclog.Infof("negative literal index: %d", op.operand)
+				return Pattern{}, ErrInvalidPattern
+			}
+			if pushMSeen {
+				tailLen++
+			}
+			stack++
+		case utilities.OpConcatN:
+			if op.operand <= 0 {
+				grpclog.Infof("negative concat size: %d", op.operand)
+				return Pattern{}, ErrInvalidPattern
+			}
+			stack -= op.operand
+			if stack < 0 {
+				grpclog.Print("stack underflow")
+				return Pattern{}, ErrInvalidPattern
+			}
+			stack++
+		case utilities.OpCapture:
+			if op.operand < 0 || len(pool) <= op.operand {
+				grpclog.Infof("variable name index out of bound: %d", op.operand)
+				return Pattern{}, ErrInvalidPattern
+			}
+			v := pool[op.operand]
+			op.operand = len(vars)
+			vars = append(vars, v)
+			stack--
+			if stack < 0 {
+				grpclog.Infof("stack underflow")
+				return Pattern{}, ErrInvalidPattern
+			}
+		default:
+			grpclog.Infof("invalid opcode: %d", op.code)
+			return Pattern{}, ErrInvalidPattern
+		}
+
+		if maxstack < stack {
+			maxstack = stack
+		}
+		typedOps = append(typedOps, op)
+	}
+	return Pattern{
+		ops:             typedOps,
+		pool:            pool,
+		vars:            vars,
+		stacksize:       maxstack,
+		tailLen:         tailLen,
+		verb:            verb,
+		assumeColonVerb: options.assumeColonVerb,
+	}, nil
+}
+
+// MustPattern is a helper function which makes it easier to call NewPattern in variable initialization.
+func MustPattern(p Pattern, err error) Pattern {
+	if err != nil {
+		grpclog.Fatalf("Pattern initialization failed: %v", err)
+	}
+	return p
+}
+
+// Match examines components if it matches to the Pattern.
+// If it matches, the function returns a mapping from field paths to their captured values.
+// If otherwise, the function returns an error.
+func (p Pattern) Match(components []string, verb string) (map[string]string, error) {
+	if p.verb != verb {
+		if p.assumeColonVerb || p.verb != "" {
+			return nil, ErrNotMatch
+		}
+		if len(components) == 0 {
+			components = []string{":" + verb}
+		} else {
+			components = append([]string{}, components...)
+			components[len(components)-1] += ":" + verb
+		}
+		verb = ""
+	}
+
+	var pos int
+	stack := make([]string, 0, p.stacksize)
+	captured := make([]string, len(p.vars))
+	l := len(components)
+	for _, op := range p.ops {
+		switch op.code {
+		case utilities.OpNop:
+			continue
+		case utilities.OpPush, utilities.OpLitPush:
+			if pos >= l {
+				return nil, ErrNotMatch
+			}
+			c := components[pos]
+			if op.code == utilities.OpLitPush {
+				if lit := p.pool[op.operand]; c != lit {
+					return nil, ErrNotMatch
+				}
+			}
+			stack = append(stack, c)
+			pos++
+		case utilities.OpPushM:
+			end := len(components)
+			if end < pos+p.tailLen {
+				return nil, ErrNotMatch
+			}
+			end -= p.tailLen
+			stack = append(stack, strings.Join(components[pos:end], "/"))
+			pos = end
+		case utilities.OpConcatN:
+			n := op.operand
+			l := len(stack) - n
+			stack = append(stack[:l], strings.Join(stack[l:], "/"))
+		case utilities.OpCapture:
+			n := len(stack) - 1
+			captured[op.operand] = stack[n]
+			stack = stack[:n]
+		}
+	}
+	if pos < l {
+		return nil, ErrNotMatch
+	}
+	bindings := make(map[string]string)
+	for i, val := range captured {
+		bindings[p.vars[i]] = val
+	}
+	return bindings, nil
+}
+
+// Verb returns the verb part of the Pattern.
+func (p Pattern) Verb() string { return p.verb }
+
+func (p Pattern) String() string {
+	var stack []string
+	for _, op := range p.ops {
+		switch op.code {
+		case utilities.OpNop:
+			continue
+		case utilities.OpPush:
+			stack = append(stack, "*")
+		case utilities.OpLitPush:
+			stack = append(stack, p.pool[op.operand])
+		case utilities.OpPushM:
+			stack = append(stack, "**")
+		case utilities.OpConcatN:
+			n := op.operand
+			l := len(stack) - n
+			stack = append(stack[:l], strings.Join(stack[l:], "/"))
+		case utilities.OpCapture:
+			n := len(stack) - 1
+			stack[n] = fmt.Sprintf("{%s=%s}", p.vars[op.operand], stack[n])
+		}
+	}
+	segs := strings.Join(stack, "/")
+	if p.verb != "" {
+		return fmt.Sprintf("/%s:%s", segs, p.verb)
+	}
+	return "/" + segs
+}
+
+// AssumeColonVerbOpt indicates whether a path suffix after a final
+// colon may only be interpreted as a verb.
+func AssumeColonVerbOpt(val bool) PatternOpt {
+	return PatternOpt(func(o *patternOptions) {
+		o.assumeColonVerb = val
+	})
+}