Refactor libdeno.send() code to reduce boilerplate.

Also removes assignCmdId as it's currently unused.

js/fbs_util.ts

+// Copyright 2018 the Deno authors. All rights reserved. MIT license.
+import { libdeno } from "./libdeno";
+import { flatbuffers } from "flatbuffers";
+import { maybeThrowError } from "./errors";
+import { deno as fbs } from "gen/msg_generated";
+
+export function send(
+  builder: flatbuffers.Builder,
+  msgType: fbs.Any,
+  msg: flatbuffers.Offset
+): null | fbs.Base {
+  fbs.Base.startBase(builder);
+  fbs.Base.addMsg(builder, msg);
+  fbs.Base.addMsgType(builder, msgType);
+  builder.finish(fbs.Base.endBase(builder));
+
+  const resBuf = libdeno.send(builder.asUint8Array());
+  if (resBuf == null) {
+    return null;
+  } else {
+    const bb = new flatbuffers.ByteBuffer(new Uint8Array(resBuf!));
+    const baseRes = fbs.Base.getRootAsBase(bb);
+    maybeThrowError(baseRes);
+    return baseRes;
+  }
+}

js/fetch.ts

@@ -8,7 +8,7 @@ import {
   notImplemented
 } from "./util";
 import { flatbuffers } from "flatbuffers";
-import { libdeno } from "./libdeno";
+import { send } from "./fbs_util";
 import { deno as fbs } from "gen/msg_generated";
 import {
   Headers,
@@ -166,14 +166,8 @@ class FetchRequest {
     fbs.FetchReq.addId(builder, this.id);
     fbs.FetchReq.addUrl(builder, url);
     const msg = fbs.FetchReq.endFetchReq(builder);
-    fbs.Base.startBase(builder);
-    fbs.Base.addMsg(builder, msg);
-    fbs.Base.addMsgType(builder, fbs.Any.FetchReq);
-    builder.finish(fbs.Base.endBase(builder));
-    const resBuf = libdeno.send(builder.asUint8Array());
-    assert(resBuf == null);
-
-    //console.log("FetchReq sent", builder);
+    const res = send(builder, fbs.Any.FetchReq, msg);
+    assert(res == null);
   }
 }
 

js/main.ts

 // Copyright 2018 the Deno authors. All rights reserved. MIT license.
 import { flatbuffers } from "flatbuffers";
 import { deno as fbs } from "gen/msg_generated";
-import { assert, assignCmdId, log, setLogDebug } from "./util";
+import { assert, log, setLogDebug } from "./util";
 import * as os from "./os";
 import { DenoCompiler } from "./compiler";
 import { libdeno } from "./libdeno";
 import * as timers from "./timers";
 import { onFetchRes } from "./fetch";
 import { argv } from "./deno";
+import { send } from "./fbs_util";
 
-function startMsg(cmdId: number): Uint8Array {
+function sendStart(): fbs.StartRes {
   const builder = new flatbuffers.Builder();
   fbs.Start.startStart(builder);
   const startOffset = fbs.Start.endStart(builder);
-  fbs.Base.startBase(builder);
-  fbs.Base.addCmdId(builder, cmdId);
-  fbs.Base.addMsg(builder, startOffset);
-  fbs.Base.addMsgType(builder, fbs.Any.Start);
-  builder.finish(fbs.Base.endBase(builder));
-  return builder.asUint8Array();
+  const baseRes = send(builder, fbs.Any.Start, startOffset);
+  assert(baseRes != null);
+  assert(fbs.Any.StartRes === baseRes!.msgType());
+  const startRes = new fbs.StartRes();
+  assert(baseRes!.msg(startRes) != null);
+  return startRes;
 }
 
 function onMessage(ui8: Uint8Array) {
@@ -64,22 +65,7 @@ export default function denoMain() {
   // First we send an empty "Start" message to let the privlaged side know we
   // are ready. The response should be a "StartRes" message containing the CLI
   // argv and other info.
-  const cmdId = assignCmdId();
-  const res = libdeno.send(startMsg(cmdId));
-
-  // TODO(ry) Remove this conditional once main.rs gets up to speed.
-  if (res == null) {
-    console.log(`The 'Start' message got a null response.  Normally this would
-    be an error but main.rs currently does this."); Exiting without error.`);
-    return;
-  }
-
-  // Deserialize res into startResMsg.
-  const bb = new flatbuffers.ByteBuffer(res);
-  const base = fbs.Base.getRootAsBase(bb);
-  assert(fbs.Any.StartRes === base.msgType());
-  const startResMsg = new fbs.StartRes();
-  assert(base.msg(startResMsg) != null);
+  const startResMsg = sendStart();
 
   setLogDebug(startResMsg.debugFlag());
 

js/os.ts

@@ -3,20 +3,15 @@ import { ModuleInfo } from "./types";
 import { deno as fbs } from "gen/msg_generated";
 import { assert } from "./util";
 import * as util from "./util";
-import { maybeThrowError } from "./errors";
 import { flatbuffers } from "flatbuffers";
-import { libdeno } from "./libdeno";
+import { send } from "./fbs_util";
 
 export function exit(exitCode = 0): never {
   const builder = new flatbuffers.Builder();
   fbs.Exit.startExit(builder);
   fbs.Exit.addCode(builder, exitCode);
   const msg = fbs.Exit.endExit(builder);
-  fbs.Base.startBase(builder);
-  fbs.Base.addMsg(builder, msg);
-  fbs.Base.addMsgType(builder, fbs.Any.Exit);
-  builder.finish(fbs.Base.endBase(builder));
-  libdeno.send(builder.asUint8Array());
+  send(builder, fbs.Any.Exit, msg);
   return util.unreachable();
 }
 
@@ -33,21 +28,11 @@ export function codeFetch(
   fbs.CodeFetch.addModuleSpecifier(builder, moduleSpecifier_);
   fbs.CodeFetch.addContainingFile(builder, containingFile_);
   const msg = fbs.CodeFetch.endCodeFetch(builder);
-  fbs.Base.startBase(builder);
-  fbs.Base.addMsg(builder, msg);
-  fbs.Base.addMsgType(builder, fbs.Any.CodeFetch);
-  builder.finish(fbs.Base.endBase(builder));
-  const resBuf = libdeno.send(builder.asUint8Array());
-  assert(resBuf != null);
-  // Process CodeFetchRes
-  // TypeScript does not track `assert` from a CFA perspective, therefore not
-  // null assertion `!`
-  const bb = new flatbuffers.ByteBuffer(new Uint8Array(resBuf!));
-  const baseRes = fbs.Base.getRootAsBase(bb);
-  maybeThrowError(baseRes);
-  assert(fbs.Any.CodeFetchRes === baseRes.msgType());
+  const baseRes = send(builder, fbs.Any.CodeFetch, msg);
+  assert(baseRes != null);
+  assert(fbs.Any.CodeFetchRes === baseRes!.msgType());
   const codeFetchRes = new fbs.CodeFetchRes();
-  assert(baseRes.msg(codeFetchRes) != null);
+  assert(baseRes!.msg(codeFetchRes) != null);
   const r = {
     moduleName: codeFetchRes.moduleName(),
     filename: codeFetchRes.filename(),
@@ -72,17 +57,8 @@ export function codeCache(
   fbs.CodeCache.addSourceCode(builder, sourceCode_);
   fbs.CodeCache.addOutputCode(builder, outputCode_);
   const msg = fbs.CodeCache.endCodeCache(builder);
-  fbs.Base.startBase(builder);
-  fbs.Base.addMsg(builder, msg);
-  fbs.Base.addMsgType(builder, fbs.Any.CodeCache);
-  builder.finish(fbs.Base.endBase(builder));
-  const resBuf = libdeno.send(builder.asUint8Array());
-  // Expect null or error.
-  if (resBuf != null) {
-    const bb = new flatbuffers.ByteBuffer(new Uint8Array(resBuf));
-    const baseRes = fbs.Base.getRootAsBase(bb);
-    maybeThrowError(baseRes);
-  }
+  const baseRes = send(builder, fbs.Any.CodeCache, msg);
+  assert(baseRes == null); // Expect null or error.
 }
 
 /**
@@ -119,18 +95,11 @@ export function makeTempDirSync({
     fbs.MakeTempDir.addSuffix(builder, fbSuffix);
   }
   const msg = fbs.MakeTempDir.endMakeTempDir(builder);
-  fbs.Base.startBase(builder);
-  fbs.Base.addMsg(builder, msg);
-  fbs.Base.addMsgType(builder, fbs.Any.MakeTempDir);
-  builder.finish(fbs.Base.endBase(builder));
-  const resBuf = libdeno.send(builder.asUint8Array());
-  assert(resBuf != null);
-  const bb = new flatbuffers.ByteBuffer(new Uint8Array(resBuf!));
-  const baseRes = fbs.Base.getRootAsBase(bb);
-  maybeThrowError(baseRes);
-  assert(fbs.Any.MakeTempDirRes === baseRes.msgType());
+  const baseRes = send(builder, fbs.Any.MakeTempDir, msg);
+  assert(baseRes != null);
+  assert(fbs.Any.MakeTempDirRes === baseRes!.msgType());
   const res = new fbs.MakeTempDirRes();
-  assert(baseRes.msg(res) != null);
+  assert(baseRes!.msg(res) != null);
   const path = res.path();
   assert(path != null);
   return path!;
@@ -149,23 +118,13 @@ export function readFileSync(filename: string): Uint8Array {
   fbs.ReadFileSync.startReadFileSync(builder);
   fbs.ReadFileSync.addFilename(builder, filename_);
   const msg = fbs.ReadFileSync.endReadFileSync(builder);
-  fbs.Base.startBase(builder);
-  fbs.Base.addMsg(builder, msg);
-  fbs.Base.addMsgType(builder, fbs.Any.ReadFileSync);
-  builder.finish(fbs.Base.endBase(builder));
-  const resBuf = libdeno.send(builder.asUint8Array());
-  assert(resBuf != null);
-  // TypeScript does not track `assert` from a CFA perspective, therefore not
-  // null assertion `!`
-  const bb = new flatbuffers.ByteBuffer(new Uint8Array(resBuf!));
-  const baseRes = fbs.Base.getRootAsBase(bb);
-  maybeThrowError(baseRes);
-  assert(fbs.Any.ReadFileSyncRes === baseRes.msgType());
+  const baseRes = send(builder, fbs.Any.ReadFileSync, msg);
+  assert(baseRes != null);
+  assert(fbs.Any.ReadFileSyncRes === baseRes!.msgType());
   const res = new fbs.ReadFileSyncRes();
-  assert(baseRes.msg(res) != null);
+  assert(baseRes!.msg(res) != null);
   const dataArray = res.dataArray();
   assert(dataArray != null);
-  // TypeScript cannot track assertion above, therefore not null assertion
   return new Uint8Array(dataArray!);
 }
 
@@ -226,22 +185,12 @@ function statSyncInner(filename: string, lstat: boolean): FileInfo {
   fbs.StatSync.addFilename(builder, filename_);
   fbs.StatSync.addLstat(builder, lstat);
   const msg = fbs.StatSync.endStatSync(builder);
-  fbs.Base.startBase(builder);
-  fbs.Base.addMsg(builder, msg);
-  fbs.Base.addMsgType(builder, fbs.Any.StatSync);
-  builder.finish(fbs.Base.endBase(builder));
-  const resBuf = libdeno.send(builder.asUint8Array());
-  assert(resBuf != null);
-  // TypeScript does not track `assert` from a CFA perspective, therefore not
-  // null assertion `!`
-  const bb = new flatbuffers.ByteBuffer(new Uint8Array(resBuf!));
-  const baseRes = fbs.Base.getRootAsBase(bb);
-  maybeThrowError(baseRes);
-  assert(fbs.Any.StatSyncRes === baseRes.msgType());
+  const baseRes = send(builder, fbs.Any.StatSync, msg);
+  assert(baseRes != null);
+  assert(fbs.Any.StatSyncRes === baseRes!.msgType());
   const res = new fbs.StatSyncRes();
-  assert(baseRes.msg(res) != null);
-  // TypeScript cannot track assertion above, therefore not null assertion
-  return new FileInfo(baseRes.msg(res)!);
+  assert(baseRes!.msg(res) != null);
+  return new FileInfo(res);
 }
 
 export function writeFileSync(
@@ -265,14 +214,5 @@ export function writeFileSync(
   fbs.WriteFileSync.addData(builder, dataOffset);
   fbs.WriteFileSync.addPerm(builder, perm);
   const msg = fbs.WriteFileSync.endWriteFileSync(builder);
-  fbs.Base.startBase(builder);
-  fbs.Base.addMsg(builder, msg);
-  fbs.Base.addMsgType(builder, fbs.Any.WriteFileSync);
-  builder.finish(fbs.Base.endBase(builder));
-  const resBuf = libdeno.send(builder.asUint8Array());
-  if (resBuf != null) {
-    const bb = new flatbuffers.ByteBuffer(new Uint8Array(resBuf!));
-    const baseRes = fbs.Base.getRootAsBase(bb);
-    maybeThrowError(baseRes);
-  }
+  send(builder, fbs.Any.WriteFileSync, msg);
 }

js/timers.ts

@@ -3,7 +3,7 @@ import { assert } from "./util";
 import * as util from "./util";
 import { deno as fbs } from "gen/msg_generated";
 import { flatbuffers } from "flatbuffers";
-import { libdeno } from "./libdeno";
+import { send } from "./fbs_util";
 
 let nextTimerId = 1;
 
@@ -60,13 +60,8 @@ function startTimer(
   fbs.TimerStart.addInterval(builder, timer.interval);
   fbs.TimerStart.addDelay(builder, timer.delay);
   const msg = fbs.TimerStart.endTimerStart(builder);
-  fbs.Base.startBase(builder);
-  fbs.Base.addMsg(builder, msg);
-  fbs.Base.addMsgType(builder, fbs.Any.TimerStart);
-  builder.finish(fbs.Base.endBase(builder));
-  const resBuf = libdeno.send(builder.asUint8Array());
-  assert(resBuf == null);
-
+  const baseRes = send(builder, fbs.Any.TimerStart, msg);
+  assert(baseRes == null);
   return timer.id;
 }
 
@@ -95,10 +90,6 @@ export function clearTimer(id: number) {
   fbs.TimerClear.startTimerClear(builder);
   fbs.TimerClear.addId(builder, id);
   const msg = fbs.TimerClear.endTimerClear(builder);
-  fbs.Base.startBase(builder);
-  fbs.Base.addMsg(builder, msg);
-  fbs.Base.addMsgType(builder, fbs.Any.TimerClear);
-  builder.finish(fbs.Base.endBase(builder));
-  const resBuf = libdeno.send(builder.asUint8Array());
-  assert(resBuf == null);
+  const res = send(builder, fbs.Any.TimerClear, msg);
+  assert(res == null);
 }

js/util.ts

@@ -21,14 +21,6 @@ export function assert(cond: boolean, msg = "assert") {
   }
 }
 
-let cmdIdCounter = 0;
-export function assignCmdId(): number {
-  // TODO(piscisaureus) Safely re-use so they don't overflow.
-  const cmdId = ++cmdIdCounter;
-  assert(cmdId < 2 ** 32, "cmdId overflow");
-  return cmdId;
-}
-
 export function typedArrayToArrayBuffer(ta: TypedArray): ArrayBuffer {
   const ab = ta.buffer.slice(ta.byteOffset, ta.byteOffset + ta.byteLength);
   return ab as ArrayBuffer;