diff --git a/Makefile b/Makefile
index ff0afd87006..3d6a6ec7b42 100644
--- a/Makefile
+++ b/Makefile
@@ -8,8 +8,8 @@ GO_PLUGIN=bin/protoc-gen-go
 GO_PLUGIN_PKG=github.com/golang/protobuf/protoc-gen-go
 SWAGGER_PLUGIN=bin/protoc-gen-swagger
 SWAGGER_PLUGIN_SRC= utilities/doc.go \
-		    utilities/name.go \
 		    utilities/pattern.go \
+		    utilities/trie.go \
 		    protoc-gen-swagger/genswagger/generator.go \
 		    protoc-gen-swagger/genswagger/template.go \
 		    protoc-gen-swagger/main.go
diff --git a/examples/examplepb/a_bit_of_everything.pb.gw.go b/examples/examplepb/a_bit_of_everything.pb.gw.go
index 4d3bbb091e6..75cf12cc89a 100644
--- a/examples/examplepb/a_bit_of_everything.pb.gw.go
+++ b/examples/examplepb/a_bit_of_everything.pb.gw.go
@@ -28,7 +28,7 @@ var _ codes.Code
 var _ io.Reader
 var _ = runtime.String
 var _ = json.Marshal
-var _ = utilities.PascalFromSnake
+var _ = utilities.NewDoubleArray
 
 var (
 	filter_ABitOfEverythingService_Create_0 = &utilities.DoubleArray{Encoding: map[string]int{"float_value": 0, "double_value": 1, "int64_value": 2, "uint64_value": 3, "int32_value": 4, "fixed64_value": 5, "fixed32_value": 6, "bool_value": 7, "string_value": 8, "uint32_value": 9, "sfixed32_value": 10, "sfixed64_value": 11, "sint32_value": 12, "sint64_value": 13}, Base: []int{1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, Check: []int{0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}}
diff --git a/examples/examplepb/echo_service.pb.gw.go b/examples/examplepb/echo_service.pb.gw.go
index 9927d88328f..1e7f121f023 100644
--- a/examples/examplepb/echo_service.pb.gw.go
+++ b/examples/examplepb/echo_service.pb.gw.go
@@ -27,7 +27,7 @@ var _ codes.Code
 var _ io.Reader
 var _ = runtime.String
 var _ = json.Marshal
-var _ = utilities.PascalFromSnake
+var _ = utilities.NewDoubleArray
 
 func request_EchoService_Echo_0(ctx context.Context, client EchoServiceClient, req *http.Request, pathParams map[string]string) (proto.Message, error) {
 	var protoReq SimpleMessage
diff --git a/examples/examplepb/flow_combination.pb.gw.go b/examples/examplepb/flow_combination.pb.gw.go
index a725b8e684d..3839f631998 100644
--- a/examples/examplepb/flow_combination.pb.gw.go
+++ b/examples/examplepb/flow_combination.pb.gw.go
@@ -27,7 +27,7 @@ var _ codes.Code
 var _ io.Reader
 var _ = runtime.String
 var _ = json.Marshal
-var _ = utilities.PascalFromSnake
+var _ = utilities.NewDoubleArray
 
 func request_FlowCombination_RpcEmptyRpc_0(ctx context.Context, client FlowCombinationClient, req *http.Request, pathParams map[string]string) (proto.Message, error) {
 	var protoReq EmptyProto
diff --git a/protoc-gen-grpc-gateway/descriptor/types.go b/protoc-gen-grpc-gateway/descriptor/types.go
index afd18ddf856..5cbe6936866 100644
--- a/protoc-gen-grpc-gateway/descriptor/types.go
+++ b/protoc-gen-grpc-gateway/descriptor/types.go
@@ -5,8 +5,8 @@ import (
 	"strings"
 
 	"github.com/gengo/grpc-gateway/protoc-gen-grpc-gateway/httprule"
-	"github.com/gengo/grpc-gateway/utilities"
 	descriptor "github.com/golang/protobuf/protoc-gen-go/descriptor"
+	gogen "github.com/golang/protobuf/protoc-gen-go/generator"
 )
 
 // GoPackage represents a golang package
@@ -235,15 +235,15 @@ type FieldPathComponent struct {
 
 // RHS returns a right-hand-side expression in go for this field.
 func (c FieldPathComponent) RHS() string {
-	return utilities.PascalFromSnake(c.Name)
+	return gogen.CamelCase(c.Name)
 }
 
 // LHS returns a left-hand-side expression in go for this field.
 func (c FieldPathComponent) LHS() string {
 	if c.Target.Message.File.proto2() {
-		return fmt.Sprintf("Get%s()", utilities.PascalFromSnake(c.Name))
+		return fmt.Sprintf("Get%s()", gogen.CamelCase(c.Name))
 	}
-	return utilities.PascalFromSnake(c.Name)
+	return gogen.CamelCase(c.Name)
 }
 
 var (
diff --git a/protoc-gen-grpc-gateway/gengateway/template.go b/protoc-gen-grpc-gateway/gengateway/template.go
index 57bd5210ac1..6eaff63bb7e 100644
--- a/protoc-gen-grpc-gateway/gengateway/template.go
+++ b/protoc-gen-grpc-gateway/gengateway/template.go
@@ -114,7 +114,7 @@ var _ codes.Code
 var _ io.Reader
 var _ = runtime.String
 var _ = json.Marshal
-var _ = utilities.PascalFromSnake
+var _ = utilities.NewDoubleArray
 `))
 
 	handlerTemplate = template.Must(template.New("handler").Parse(`
diff --git a/runtime/query.go b/runtime/query.go
index 82b07886ca3..e7592307aca 100644
--- a/runtime/query.go
+++ b/runtime/query.go
@@ -12,7 +12,7 @@ import (
 )
 
 // PopulateQueryParameters populates "values" into "msg".
-// A value is ignored if its key starts with one of the elements in "filters".
+// A value is ignored if its key starts with one of the elements in "filter".
 func PopulateQueryParameters(msg proto.Message, values url.Values, filter *utilities.DoubleArray) error {
 	for key, values := range values {
 		fieldPath := strings.Split(key, ".")
@@ -44,7 +44,7 @@ func populateFieldValueFromPath(msg proto.Message, fieldPath []string, values []
 		if !isLast && m.Kind() != reflect.Struct {
 			return fmt.Errorf("non-aggregate type in the mid of path: %s", strings.Join(fieldPath, "."))
 		}
-		f := m.FieldByName(utilities.PascalFromSnake(fieldName))
+		f := fieldByProtoName(m, fieldName)
 		if !f.IsValid() {
 			glog.Warningf("field not found in %T: %s", msg, strings.Join(fieldPath, "."))
 			return nil
@@ -83,6 +83,18 @@ func populateFieldValueFromPath(msg proto.Message, fieldPath []string, values []
 	return populateField(m, values[0])
 }
 
+// fieldByProtoName looks up a field whose corresponding protobuf field name is "name".
+// "m" must be a struct value. It returns zero reflect.Value if no such field found.
+func fieldByProtoName(m reflect.Value, name string) reflect.Value {
+	props := proto.GetProperties(m.Type())
+	for _, p := range props.Prop {
+		if p.OrigName == name {
+			return m.FieldByName(p.Name)
+		}
+	}
+	return reflect.Value{}
+}
+
 func populateRepeatedField(f reflect.Value, values []string) error {
 	elemType := f.Type().Elem()
 	conv, ok := convFromType[elemType.Kind()]
diff --git a/utilities/name.go b/utilities/name.go
deleted file mode 100644
index 01fdb6097b2..00000000000
--- a/utilities/name.go
+++ /dev/null
@@ -1,82 +0,0 @@
-package utilities
-
-// PascalFromSnake converts an identifier in snake_case into PascalCase.
-func PascalFromSnake(s string) string {
-	// adopted from github.com/golang/protobuf/protoc-gen-go/generator/generator.go
-	//
-	// Copyright 2010 The Go Authors.  All rights reserved.
-	// https://github.com/golang/protobuf
-	//
-	// Redistribution and use in source and binary forms, with or without
-	// modification, are permitted provided that the following conditions are
-	// met:
-	//
-	//     * Redistributions of source code must retain the above copyright
-	// notice, this list of conditions and the following disclaimer.
-	//     * Redistributions in binary form must reproduce the above
-	// copyright notice, this list of conditions and the following disclaimer
-	// in the documentation and/or other materials provided with the
-	// distribution.
-	//     * Neither the name of Google Inc. nor the names of its
-	// contributors may be used to endorse or promote products derived from
-	// this software without specific prior written permission.
-	//
-	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-	// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-	// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-	// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-	// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-	// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-	// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-	// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-	// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-	// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-	if s == "" {
-		return ""
-	}
-	t := make([]byte, 0, 32)
-	i := 0
-	if s[0] == '_' {
-		// Need a capital letter; drop the '_'.
-		t = append(t, 'X')
-		i++
-	}
-	// Invariant: if the next letter is lower case, it must be converted
-	// to upper case.
-	// That is, we process a word at a time, where words are marked by _ or
-	// upper case letter. Digits are treated as words.
-	for ; i < len(s); i++ {
-		c := s[i]
-		if c == '_' && i+1 < len(s) && isASCIILower(s[i+1]) {
-			continue // Skip the underscore in s.
-		}
-		if isASCIIDigit(c) {
-			t = append(t, c)
-			continue
-		}
-		// Assume we have a letter now - if not, it's a bogus identifier.
-		// The next word is a sequence of characters that must start upper case.
-		if isASCIILower(c) {
-			c ^= ' ' // Make it a capital letter.
-		}
-		t = append(t, c) // Guaranteed not lower case.
-		// Accept lower case sequence that follows.
-		for i+1 < len(s) && isASCIILower(s[i+1]) {
-			i++
-			t = append(t, s[i])
-		}
-	}
-	return string(t)
-}
-
-// Is c an ASCII lower-case letter?
-func isASCIILower(c byte) bool {
-	return 'a' <= c && c <= 'z'
-}
-
-// Is c an ASCII digit?
-func isASCIIDigit(c byte) bool {
-	return '0' <= c && c <= '9'
-}
diff --git a/utilities/name_test.go b/utilities/name_test.go
deleted file mode 100644
index a33dde74e8b..00000000000
--- a/utilities/name_test.go
+++ /dev/null
@@ -1,22 +0,0 @@
-package utilities_test
-
-import (
-	"testing"
-
-	"github.com/gengo/grpc-gateway/utilities"
-)
-
-func TestPascalToSnake(t *testing.T) {
-	for _, spec := range []struct {
-		input, want string
-	}{
-		{input: "value", want: "Value"},
-		{input: "prefixed_value", want: "PrefixedValue"},
-		{input: "foo_id", want: "FooId"},
-	} {
-		got := utilities.PascalFromSnake(spec.input)
-		if got != spec.want {
-			t.Errorf("utilities.PascalFromSnake(%q) = %q; want %q", spec.input, got, spec.want)
-		}
-	}
-}