Use the old way to read enum (#75)

Cargo.toml

@@ -13,7 +13,7 @@ categories = ["algorithms", "database-implementations"]
 
 [dependencies]
 log = "0.4.1"
-protobuf = "2.0"
+protobuf = "~2.0.0"
 quick-error = "1.2.1"
 rand = "0.4"
 fxhash = "0.2.1"

generate-proto.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+protoc proto/eraftpb.proto --rust_out=src/
+# TODO: remove this once stepancheg/rust-protobuf#233 is resolved.
+python <<EOF
+import re
+with open("src/eraftpb.rs") as reader:
+    src = reader.read()
+
+res = re.sub('::protobuf::rt::read_proto3_enum_with_unknown_fields_into\(([^,]+), ([^,]+), &mut ([^,]+), [^\)]+\)\?', 'if \\\\1 == ::protobuf::wire_format::WireTypeVarint {\\\\3 = \\\\2.read_enum()?;} else { return ::std::result::Result::Err(::protobuf::rt::unexpected_wire_type(wire_type)); }', src)
+
+with open("src/eraftpb.rs", "w") as writer:
+    writer.write(res)
+EOF

src/eraftpb.rs

@@ -1,4 +1,4 @@
-// This file is generated by rust-protobuf 1.6.0. Do not edit
+// This file is generated by rust-protobuf 2.0.2. Do not edit
 // @generated
 
 // https://github.com/Manishearth/rust-clippy/issues/702
@@ -163,7 +163,7 @@ impl ::protobuf::Message for Entry {
             let (field_number, wire_type) = is.read_tag_unpack()?;
             match field_number {
                 1 => {
-                    ::protobuf::rt::read_proto3_enum_with_unknown_fields_into(wire_type, is, &mut self.entry_type, 1, &mut self.unknown_fields)?
+                    if wire_type == ::protobuf::wire_format::WireTypeVarint {self.entry_type = is.read_enum()?;} else { return ::std::result::Result::Err(::protobuf::rt::unexpected_wire_type(wire_type)); }
                 },
                 2 => {
                     if wire_type != ::protobuf::wire_format::WireTypeVarint {
@@ -1095,7 +1095,7 @@ impl ::protobuf::Message for Message {
             let (field_number, wire_type) = is.read_tag_unpack()?;
             match field_number {
                 1 => {
-                    ::protobuf::rt::read_proto3_enum_with_unknown_fields_into(wire_type, is, &mut self.msg_type, 1, &mut self.unknown_fields)?
+                    if wire_type == ::protobuf::wire_format::WireTypeVarint {self.msg_type = is.read_enum()?;} else { return ::std::result::Result::Err(::protobuf::rt::unexpected_wire_type(wire_type)); }
                 },
                 2 => {
                     if wire_type != ::protobuf::wire_format::WireTypeVarint {
@@ -1945,7 +1945,7 @@ impl ::protobuf::Message for ConfChange {
                     self.id = tmp;
                 },
                 2 => {
-                    ::protobuf::rt::read_proto3_enum_with_unknown_fields_into(wire_type, is, &mut self.change_type, 2, &mut self.unknown_fields)?
+                    if wire_type == ::protobuf::wire_format::WireTypeVarint {self.change_type = is.read_enum()?;} else { return ::std::result::Result::Err(::protobuf::rt::unexpected_wire_type(wire_type)); }
                 },
                 3 => {
                     if wire_type != ::protobuf::wire_format::WireTypeVarint {