server stuff

src/api/game.worker.js

@@ -4,6 +4,8 @@ import SpawnBinary from './DiabloSpawn.wasm';
 import SpawnModule from './DiabloSpawn.jscc';
 import axios from 'axios';
 
+import websocket_open from './websocket';
+
 const DiabloSize = 1466809;
 const SpawnSize = 1337416;
 
@@ -16,6 +18,7 @@ let files = null;
 let renderBatch = null;
 let drawBelt = null;
 let is_spawn = false;
+let websocket = null;
 
 const ChunkSize = 1 << 20;
 class RemoteFile {
@@ -116,8 +119,35 @@ const DApi = {
     worker.postMessage({action: "keyboard", rect: null});
   },
 
+  use_websocket(flag) {
+    if (flag) {
+      if (!websocket || websocket.readyState !== 1) {
+        const sock = websocket = websocket_open('ws://diablo.rivsoft.net/', data => {
+          if (websocket === sock) {
+            try_api(() => {
+              const ptr = wasm._DApi_AllocPacket(data.byteLength);
+              wasm.HEAPU8.set(new Uint8Array(data), ptr);
+            });
+          }
+        }, code => {
+          if (typeof code !== "number") {
+            worker.postMessage({action: "error", error: code.toString(), stack: code.stack});
+            code = 3;
+          }
+          call_api("SNet_WebsocketStatus", code);
+        });
+      } else {
+        call_api("SNet_WebsocketStatus", 0);
+      }
+    } else {
+      if (websocket) {
+        websocket.close();
+      }
+      websocket = null;
+    }
+  },
   websocket_closed() {
-    return false;
+    return websocket ? websocket.readyState !== 1 : false;
   },
 };
 
@@ -234,7 +264,9 @@ let maxSoundId = 0, maxBatchId = 0;
 
 let packetBatch = null;
 DApi.websocket_send = function(data) {
-  if (packetBatch) {
+  if (websocket) {
+    websocket.send(data);
+  } else if (packetBatch) {
     packetBatch.push(data.slice().buffer);
   } else {
     worker.postMessage({action: "packet", buffer: data});
@@ -249,9 +281,6 @@ function try_api(func) {
   try {
     func();
   } catch (e) {
-    if (typeof e === "string") {
-      worker.postMessage({action: ""})
-    }
     worker.postMessage({action: "error", error: e.toString(), stack: e.stack});
   }
 }

src/api/packet.js

@@ -0,0 +1,260 @@
+export class buffer_reader {
+  constructor(buffer) {
+    this.buffer = (buffer instanceof Uint8Array ? buffer : new Uint8Array(buffer));
+    this.pos = 0;
+  }
+  done() {
+    return this.pos === this.buffer.byteLength;
+  }
+  read8() {
+    if (this.pos >= this.buffer.byteLength) {
+      throw Error('packet too small');
+    }
+    return this.buffer[this.pos++];
+  }
+  read16() {
+    const {pos, buffer} = this;
+    if (pos + 2 > buffer.byteLength) {
+      throw Error('packet too small');
+    }
+    const result = buffer[pos] | (buffer[pos + 1] << 8);
+    this.pos += 2;
+    return result;
+  }
+  read32() {
+    const {pos, buffer} = this;
+    if (pos + 4 > buffer.byteLength) {
+      throw Error('packet too small');
+    }
+    const result = buffer[pos] | (buffer[pos + 1] << 8) | (buffer[pos + 2] << 16) | (buffer[pos + 3] << 24);
+    this.pos += 4;
+    return result;
+  }
+  read_str() {
+    const length = this.read8();
+    const {pos, buffer} = this;
+    if (pos + length > buffer.byteLength) {
+      throw Error('packet too small');
+    }
+    const result = String.fromCharCode(...buffer.subarray(pos, pos + length));
+    this.pos += length;
+    return result;
+  }
+  rest() {
+    const size = this.read32();
+    const result = this.buffer.subarray(this.pos, this.pos + size);
+    this.pos += size;
+    return result;
+  }
+}
+export class buffer_writer {
+  constructor(length) {
+    this.buffer = new Uint8Array(length);
+    this.pos = 0;
+  }
+  get result() {
+    return this.buffer.buffer;
+  }
+  write8(value) {
+    this.buffer[this.pos++] = value;
+    return this;
+  }
+  write16(value) {
+    const {pos, buffer} = this;
+    buffer[pos] = value;
+    buffer[pos + 1] = value >> 8;
+    this.pos += 2;
+    return this;
+  }
+  write32(value) {
+    const {pos, buffer} = this;
+    buffer[pos] = value;
+    buffer[pos + 1] = value >> 8;
+    buffer[pos + 2] = value >> 16;
+    buffer[pos + 3] = value >> 24;
+    this.pos += 4;
+    return this;
+  }
+  write_str(value) {
+    const length = value.length;
+    this.write8(length);
+    const {pos, buffer} = this;
+    for (let i = 0; i < length; ++i) {
+      buffer[pos + i] = value.charCodeAt(i);
+    }
+    this.pos += length;
+    return this;
+  }
+  rest(value) {
+    this.write32(value.byteLength);
+    this.buffer.set(value, this.pos);
+    this.pos += value.byteLength;
+    return this;
+  }
+}
+
+export const RejectionReason = {
+  JOIN_SUCCESS: 0x00,
+  JOIN_ALREADY_IN_GAME: 0x01,
+  JOIN_GAME_NOT_FOUND: 0x02,
+  JOIN_INCORRECT_PASSWORD: 0x03,
+  JOIN_VERSION_MISMATCH: 0x04,
+  JOIN_GAME_FULL: 0x05,
+  CREATE_GAME_EXISTS: 0x06,
+};
+
+export function read_packet(reader, types) {
+  const code = reader.read8();
+  const cls = Object.values(types).find(cls => cls.code === code);
+  if (!cls) {
+    throw Error('invalid packet code');
+  }
+  return {type: cls, packet: cls.read(reader)};
+}
+export function packet_size(type, packet) {
+  return (typeof type.size === "function" ? type.size(packet) : type.size) + 1;
+}
+export function write_packet(type, packet) {
+  const size = packet_size(type, packet);
+  return type.write(new buffer_writer(size).write8(type.code), packet).result;
+}
+
+export function make_batch(types) {
+  return {
+    code: 0x00,
+    read: reader => {
+      const count = reader.read16();
+      const packets = [];
+      for (let i = 0; i < count; ++i) {
+        packets.push(read_packet(reader, types()));
+      }
+      return packets;
+    },
+    size: packets => packets.reduce((sum, {type, packet}) => sum + packet_size(type, packet), 2),
+    write: (writer, packets) => {
+      writer.write16(packets.length);
+      for (let {type, packet} of packets) {
+        type.write(writer.write8(type.code), packet);
+      }
+      return writer;
+    },
+  };
+}
+
+export const server_packet = {
+  info: {
+    code: 0x32,
+    read: reader => ({version: reader.read32()}),
+    size: 4,
+    write: (writer, {version}) => writer.write32(version),
+  },
+  game_list: {
+    code: 0x21,
+    read: reader => {
+      const count = reader.read16();
+      const games = [];
+      for (let i = 0; i < count; ++i) {
+        games.push({type: reader.read32(), name: reader.read_str()});
+      }
+      return {games};
+    },
+    size: ({games}) => games.reduce((sum, {name}) => sum + 5 + name.length, 2),
+    write: (writer, {games}) => {
+      writer.write16(games.length);
+      for (let {type, name} of games) {
+        writer.write32(type);
+        writer.write_str(name);
+      }
+      return writer;
+    },
+  },
+  join_accept: {
+    code: 0x12,
+    read: reader => ({cookie: reader.read32(), index: reader.read8(), seed: reader.read32(), difficulty: reader.read32()}),
+    size: 13,
+    write: (writer, {cookie, index, seed, difficulty}) => writer.write32(cookie).write8(index).write32(seed).write32(difficulty),
+  },
+  join_reject: {
+    code: 0x15,
+    read: reader => ({cookie: reader.read32(), reason: reader.read8()}),
+    size: 5,
+    write: (writer, {cookie, reason}) => writer.write32(cookie).write8(reason),
+  },
+  connect: {
+    code: 0x13,
+    read: reader => ({id: reader.read8()}),
+    size: 1,
+    write: (writer, {id}) => writer.write8(id),
+  },
+  disconnect: {
+    code: 0x14,
+    read: reader => ({id: reader.read8(), reason: reader.read32()}),
+    size: 5,
+    write: (writer, {id, reason}) => writer.write8(id).write32(reason),
+  },
+  message: {
+    code: 0x01,
+    read: reader => ({id: reader.read8(), payload: reader.rest()}),
+    size: ({payload}) => 5 + payload.byteLength,
+    write: (writer, {id, payload}) => writer.write8(id).rest(payload),
+  },
+  turn: {
+    code: 0x02,
+    read: reader => ({id: reader.read8(), turn: reader.read32()}),
+    size: 5,
+    write: (writer, {id, turn}) => writer.write8(id).write32(turn),
+  },
+  batch: make_batch(() => server_packet),
+};
+
+export const client_packet = {
+  info: {
+    code: 0x31,
+    read: reader => ({version: reader.read32()}),
+    size: 4,
+    write: (writer, {version}) => writer.write32(version),
+  },
+  game_list: {
+    code: 0x21,
+    read: () => ({}),
+    size: 0,
+    write: writer => writer,
+  },
+  create_game: {
+    code: 0x22,
+    read: reader => ({cookie: reader.read32(), name: reader.read_str(), password: reader.read_str(), difficulty: reader.read32()}),
+    size: ({name, password}) => 10 + name.length + password.length,
+    write: (writer, {cookie, name, password, difficulty}) => writer.write32(cookie).write_str(name).write_str(password).write32(difficulty),
+  },
+  join_game: {
+    code: 0x23,
+    read: reader => ({cookie: reader.read32(), name: reader.read_str(), password: reader.read_str()}),
+    size: ({name, password}) => 6 + name.length + password.length,
+    write: (writer, {cookie, name, password}) => writer.write32(cookie).write_str(name).write_str(password),
+  },
+  leave_game: {
+    code: 0x24,
+    read: () => ({}),
+    size: 0,
+    write: writer => writer,
+  },
+  drop_player: {
+    code: 0x03,
+    read: reader => ({id: reader.read8(), reason: reader.read32()}),
+    size: 5,
+    write: (writer, {id, reason}) => writer.write8(id).write32(reason),
+  },
+  message: {
+    code: 0x01,
+    read: reader => ({id: reader.read8(), payload: reader.rest()}),
+    size: ({payload}) => 5 + payload.byteLength,
+    write: (writer, {id, payload}) => writer.write8(id).rest(payload),
+  },
+  turn: {
+    code: 0x02,
+    read: reader => ({turn: reader.read32()}),
+    size: 4,
+    write: (writer, {turn}) => writer.write32(turn),
+  },
+  batch: make_batch(() => server_packet),
+};

src/api/webrtc.js

@@ -1,210 +1,5 @@
 import Peer from 'peerjs';
-
+import { buffer_reader, read_packet, write_packet, client_packet, server_packet, RejectionReason } from './packet';
-class buffer_reader {
-  constructor(buffer) {
-    this.buffer = (buffer instanceof Uint8Array ? buffer : new Uint8Array(buffer));
-    this.pos = 0;
-  }
-  done() {
-    return this.pos === this.buffer.byteLength;
-  }
-  read8() {
-    if (this.pos >= this.buffer.byteLength) {
-      throw Error('packet too small');
-    }
-    return this.buffer[this.pos++];
-  }
-  read16() {
-    const {pos, buffer} = this;
-    if (pos + 2 > buffer.byteLength) {
-      throw Error('packet too small');
-    }
-    const result = buffer[pos] | (buffer[pos + 1] << 8);
-    this.pos += 2;
-    return result;
-  }
-  read32() {
-    const {pos, buffer} = this;
-    if (pos + 4 > buffer.byteLength) {
-      throw Error('packet too small');
-    }
-    const result = buffer[pos] | (buffer[pos + 1] << 8) | (buffer[pos + 2] << 16) | (buffer[pos + 3] << 24);
-    this.pos += 4;
-    return result;
-  }
-  read_str() {
-    const length = this.read8();
-    const {pos, buffer} = this;
-    if (pos + length > buffer.byteLength) {
-      throw Error('packet too small');
-    }
-    const result = String.fromCharCode(...buffer.subarray(pos, pos + length));
-    this.pos += length;
-    return result;
-  }
-  rest() {
-    const result = this.buffer.subarray(this.pos);
-    this.pos = this.buffer.length;
-    return result;
-  }
-}
-class buffer_writer {
-  constructor(length) {
-    this.buffer = new Uint8Array(length);
-    this.pos = 0;
-  }
-  get result() {
-    return this.buffer.buffer;
-  }
-  write8(value) {
-    this.buffer[this.pos++] = value;
-    return this;
-  }
-  write16(value) {
-    const {pos, buffer} = this;
-    buffer[pos] = value;
-    buffer[pos + 1] = value >> 8;
-    this.pos += 2;
-    return this;
-  }
-  write32(value) {
-    const {pos, buffer} = this;
-    buffer[pos] = value;
-    buffer[pos + 1] = value >> 8;
-    buffer[pos + 2] = value >> 16;
-    buffer[pos + 3] = value >> 24;
-    this.pos += 4;
-    return this;
-  }
-  write_str(value) {
-    const length = value.length;
-    this.write8(length);
-    const {pos, buffer} = this;
-    for (let i = 0; i < length; ++i) {
-      buffer[pos + i] = value.charCodeAt(i);
-    }
-    this.pos += length;
-    return this;
-  }
-  rest(value) {
-    this.buffer.set(value, this.pos);
-    return this;
-  }
-}
-
-const RejectionReason = {
-  JOIN_SUCCESS: 0x00,
-  JOIN_ALREADY_IN_GAME: 0x01,
-  JOIN_GAME_NOT_FOUND: 0x02,
-  JOIN_INCORRECT_PASSWORD: 0x03,
-  JOIN_VERSION_MISMATCH: 0x04,
-  JOIN_GAME_FULL: 0x05,
-  CREATE_GAME_EXISTS: 0x06,
-};
-
-const server_packet = {
-  info: {
-    code: 0x32,
-    read: reader => ({version: reader.read32()}),
-    write: ({version}) => new buffer_writer(5).write8(server_packet.info.code).write32(version).result,
-  },
-  game_list: {
-    code: 0x21,
-    read: reader => {
-      const count = reader.read8();
-      const games = [];
-      for (let i = 0; i < count; ++i) {
-        games.push({type: reader.read32(), name: reader.read_str()});
-      }
-      return {games};
-    },
-    write: ({games}) => {
-      const writer = new buffer_writer(games.reduce((sum, {name}) => sum + 5 + name.length, 2));
-      writer.write8(server_packet.game_list.code);
-      writer.write8(games.length);
-      for (let {code, name} of games) {
-        writer.write32(code);
-        writer.write_str(name);
-      }
-      return writer.result;
-    },
-  },
-  join_accept: {
-    code: 0x12,
-    read: reader => ({cookie: reader.read32(), index: reader.read8(), seed: reader.read32(), difficulty: reader.read32()}),
-    write: ({cookie, index, seed, difficulty}) => new buffer_writer(14).write8(server_packet.join_accept.code).write32(cookie).write8(index).write32(seed).write32(difficulty).result,
-  },
-  join_reject: {
-    code: 0x15,
-    read: reader => ({cookie: reader.read32(), reason: reader.read8()}),
-    write: ({cookie, reason}) => new buffer_writer(6).write8(server_packet.join_reject.code).write32(cookie).write8(reason).result,
-  },
-  connect: {
-    code: 0x13,
-    read: reader => ({id: reader.read8()}),
-    write: ({id}) => new buffer_writer(2).write8(server_packet.connect.code).write8(id).result,
-  },
-  disconnect: {
-    code: 0x14,
-    read: reader => ({id: reader.read8(), reason: reader.read32()}),
-    write: ({id, reason}) => new buffer_writer(6).write8(server_packet.disconnect.code).write8(id).write32(reason).result,
-  },
-  message: {
-    code: 0x01,
-    read: reader => ({id: reader.read8(), payload: reader.rest()}),
-    write: ({id, payload}) => new buffer_writer(2 + payload.byteLength).write8(server_packet.message.code).write8(id).rest(payload).result,
-  },
-  turn: {
-    code: 0x02,
-    read: reader => ({id: reader.read8(), turn: reader.read32()}),
-    write: ({id, turn}) => new buffer_writer(6).write8(server_packet.turn.code).write8(id).write32(turn).result,
-  },
-};
-
-const client_packet = {
-  info: {
-    code: 0x31,
-    read: reader => ({version: reader.read32()}),
-    write: ({version}) => new buffer_writer(5).write8(client_packet.info.code).write32(version).result,
-  },
-  game_list: {
-    code: 0x21,
-    read: () => ({}),
-    write: () => new buffer_writer(1).write8(client_packet.game_list.code).result,
-  },
-  create_game: {
-    code: 0x22,
-    read: reader => ({cookie: reader.read32(), name: reader.read_str(), password: reader.read_str(), difficulty: reader.read32()}),
-    write: ({cookie, name, password, difficulty}) => new buffer_writer(11 + name.length + password.length)
-      .write8(client_packet.create_game.code).write32(cookie).write_str(name).write_str(password).write32(difficulty).result,
-  },
-  join_game: {
-    code: 0x23,
-    read: reader => ({cookie: reader.read32(), name: reader.read_str(), password: reader.read_str()}),
-    write: ({cookie, name, password}) => new buffer_writer(7 + name.length + password.length)
-      .write8(client_packet.join_game.code).write32(cookie).write_str(name).write_str(password).result,
-  },
-  leave_game: {
-    code: 0x24,
-    read: () => ({}),
-    write: () => new buffer_writer(1).write8(client_packet.leave_game.code).result,
-  },
-  drop_player: {
-    code: 0x03,
-    read: reader => ({id: reader.read8(), reason: reader.read32()}),
-    write: ({id, reason}) => new buffer_writer(6).write8(client_packet.drop_player.code).write8(id).write32(reason).result,
-  },
-  message: {
-    code: 0x01,
-    read: reader => ({id: reader.read8(), payload: reader.rest()}),
-    write: ({id, payload}) => new buffer_writer(2 + payload.byteLength).write8(client_packet.message.code).write8(id).rest(payload).result,
-  },
-  turn: {
-    code: 0x02,
-    read: reader => ({turn: reader.read32()}),
-    write: ({turn}) => new buffer_writer(5).write8(client_packet.turn.code).write32(turn).result,
-  },
-};
 
 /*function log_packet(data, type) {
   const reader = new buffer_reader(data);
@@ -262,15 +57,12 @@ class webrtc_server {
     const peer = {conn};
     conn.on('data', packet => {
       const reader = new buffer_reader(packet);
-      const code = reader.read8();
+      const {type, packet: pkt} = read_packet(reader, client_packet);
-      let pkt;
+      switch (type.code) {
-      switch (code) {
       case client_packet.info.code:
-        pkt = client_packet.info.read(reader);
         peer.version = pkt.version;
         break;
       case client_packet.join_game.code:
-        pkt = client_packet.join_game.read(reader);
         if (peer.version !== this.version) {
           conn.send(server_packet.join_reject.write({cookie: pkt.cookie, reason: RejectionReason.JOIN_VERSION_MISMATCH}));
         } else if (pkt.name !== this.name) {
@@ -294,7 +86,7 @@ class webrtc_server {
         break;
       default:
         if (peer.id != null) {
-          this.handle(peer.id, code, reader);
+          this.handle(peer.id, type.code, pkt);
         } else {
           return;
         }
@@ -343,23 +135,18 @@ class webrtc_server {
     }
   }
 
-  handle(id, code, reader) {
+  handle(id, code, pkt) {
-    let pkt;
     switch (code) {
     case client_packet.leave_game.code:
-      pkt = client_packet.leave_game.read(reader);
       this.drop(id, 3);
       break;
     case client_packet.drop_player.code:
-      pkt = client_packet.drop_player.read(reader);
       this.drop(pkt.id, pkt.reason);
       break;
     case client_packet.message.code:
-      pkt = client_packet.message.read(reader);
       this.send(pkt.id === 0xFF ? ~(1 << id) : (1 << pkt.id), server_packet.message.write({id, payload: pkt.payload}));
       break;
     case client_packet.turn.code:
-      pkt = client_packet.turn.read(reader);
       this.send(~(1 << id), server_packet.turn.write({id, turn: pkt.turn}));
       break;
     default:
@@ -411,18 +198,15 @@ class webrtc_client {
     this.conn.on('data', data => {
       unreg();
       const reader = new buffer_reader(data);
-      const code = reader.read8();
+      const {type, packet: pkt} = read_packet(reader, server_packet);
-      let pkt;
+      switch (type.code) {
-      switch (code) {
       case server_packet.join_accept.code:
-        pkt = server_packet.join_accept.read(reader);
         this.myplr = pkt.index;
         break;
       case server_packet.join_reject.code:
         onClose();
         break;
       case server_packet.disconnect.code:
-        pkt = server_packet.disconnect.read(reader);
         if (pkt.id === 'myplr') {
           onClose();
         }
@@ -460,15 +244,12 @@ export default function webrtc_open(onMessage) {
     send: function(packet) {
       //log_packet(packet, client_packet);
       const reader = new buffer_reader(packet);
-      const code = reader.read8();
+      const {type, packet: pkt} = read_packet(reader, client_packet);
-      let pkt;
+      switch (type.code) {
-      switch (code) {
       case client_packet.info.code:
-        pkt = client_packet.info.read(reader);
         version = pkt.version;
         break;
       case client_packet.create_game.code:
-        pkt = client_packet.create_game.read(reader);
         if (server || client) {
           onMessage(server_packet.join_reject.write({cookie: pkt.cookie, reason: RejectionReason.JOIN_ALREADY_IN_GAME}));
         } else {
@@ -476,7 +257,6 @@ export default function webrtc_open(onMessage) {
         }
         break;
       case client_packet.join_game.code:
-        pkt = client_packet.join_game.read(reader);
         if (server || client) {
           onMessage(server_packet.join_reject.write({cookie: pkt.cookie, reason: RejectionReason.JOIN_ALREADY_IN_GAME}));
         } else {
@@ -485,18 +265,18 @@ export default function webrtc_open(onMessage) {
         break;
       default:
         if (server) {
-          server.handle(0, code, reader);
+          server.handle(0, type.code, pkt);
-          if (code === client_packet.leave_game.code) {
+          if (type.code === client_packet.leave_game.code) {
             server = null;
           }
         } else if (client) {
           client.send(packet);
-          if (code === client_packet.leave_game.code) {
+          if (type.code === client_packet.leave_game.code) {
             client = null;
           }
           return;
-        } else if (code !== client_packet.leave_game.code) {
+        } else if (type.code !== client_packet.leave_game.code) {
-          throw Error(`invalid packet ${code}`);
+          throw Error(`invalid packet ${type.code}`);
         }
       }
       if (!reader.done()) {

src/api/websocket.js

@@ -1,4 +1,4 @@
-export default async function websocket_open(url, handler) {
+async function do_websocket_open(url, handler) {
   const socket = new WebSocket(url);
   socket.binaryType = "arraybuffer";
   let versionCbk = null;
@@ -9,7 +9,7 @@ export default async function websocket_open(url, handler) {
     handler(data);
   });
   await new Promise((resolve, reject) => {
-    const onError = err => reject(err);
+    const onError = err => reject(1);
     socket.addEventListener("error", onError);
     socket.addEventListener("open", () => {
       socket.removeEventListener("error", onError);
@@ -19,7 +19,7 @@ export default async function websocket_open(url, handler) {
   await new Promise((resolve, reject) => {
     const to = setTimeout(() => {
       versionCbk = null;
-      reject(Error("connection timed out"));
+      reject(1);
     }, 5000);
     versionCbk = data => {
       clearTimeout(to);
@@ -30,7 +30,7 @@ export default async function websocket_open(url, handler) {
         if (version === 1) {
           resolve();
         } else {
-          reject("server version mismatch");
+          reject(2);
         }
       }
     };
@@ -46,3 +46,40 @@ export default async function websocket_open(url, handler) {
   socket.send(clientInfo);
   return socket;
 }
+
+export default function websocket_open(url, handler, finisher) {
+  let ws = null, pending = [];
+  const proxy = {
+    get readyState() {
+      return ws ? ws.readyState : 0;
+    },
+    send(msg) {
+      if (ws) {
+        ws.send(msg);
+      } else {
+        pending.push(msg.slice());
+      }
+    },
+    close() {
+      if (ws) {
+        ws.close();
+      } else {
+        pending = null;
+      }
+    },
+  };
+  do_websocket_open(url, handler).then(sock => {
+    ws = sock;
+    if (pending) {
+      for (let msg of pending) {
+        ws.send(msg);
+      }
+    } else {
+      ws.close();
+    }
+    finisher(0);
+  }, err => {
+    finisher(err);
+  });
+  return proxy;
+}