Revert json ops (#2814)

* Revert "port more ops to JSON (#2809)"

This reverts commit 137f33733d.

* Revert "port ops to JSON: compiler, errors, fetch, files (#2804)"

This reverts commit 79f82cf10e.

* Revert "Port rest of os ops to JSON (#2802)"

This reverts commit 5b2baa5c99.

js/os.ts

@@ -1,7 +1,8 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
 import { core } from "./core";
 import * as dispatch from "./dispatch";
-import { sendSync } from "./dispatch_json";
+import { sendSync, msg, flatbuffers } from "./dispatch_flatbuffers";
+import * as dispatchJson from "./dispatch_json";
 import { assert } from "./util";
 import * as util from "./util";
 import { window } from "./window";
@@ -23,17 +24,21 @@ function setGlobals(pid_: number, noColor_: boolean): void {
  *       console.log(Deno.isTTY().stdout);
  */
 export function isTTY(): { stdin: boolean; stdout: boolean; stderr: boolean } {
-  return sendSync(dispatch.OP_IS_TTY);
+  return dispatchJson.sendSync(dispatch.OP_IS_TTY);
 }
 
 /** Exit the Deno process with optional exit code. */
 export function exit(code = 0): never {
-  sendSync(dispatch.OP_EXIT, { code });
+  dispatchJson.sendSync(dispatch.OP_EXIT, { code });
   return util.unreachable();
 }
 
 function setEnv(key: string, value: string): void {
-  sendSync(dispatch.OP_SET_ENV, { key, value });
+  const builder = flatbuffers.createBuilder();
+  const key_ = builder.createString(key);
+  const value_ = builder.createString(value);
+  const inner = msg.SetEnv.createSetEnv(builder, key_, value_);
+  sendSync(builder, msg.Any.SetEnv, inner);
 }
 
 /** Returns a snapshot of the environment variables at invocation. Mutating a
@@ -48,7 +53,7 @@ function setEnv(key: string, value: string): void {
  *       console.log(myEnv.TEST_VAR == newEnv.TEST_VAR);
  */
 export function env(): { [index: string]: string } {
-  const env = sendSync(dispatch.OP_ENV);
+  const env = dispatchJson.sendSync(dispatch.OP_ENV);
   return new Proxy(env, {
     set(obj, prop: string, value: string): boolean {
       setEnv(prop, value);
@@ -57,35 +62,35 @@ export function env(): { [index: string]: string } {
   });
 }
 
-interface Start {
-  cwd: string;
-  pid: number;
-  argv: string[];
-  mainModule: string; // Absolute URL.
-  debugFlag: boolean;
-  depsFlag: boolean;
-  typesFlag: boolean;
-  versionFlag: boolean;
-  denoVersion: string;
-  v8Version: string;
-  noColor: boolean;
-  xevalDelim: string;
+/** Send to the privileged side that we have setup and are ready. */
+function sendStart(): msg.StartRes {
+  const builder = flatbuffers.createBuilder();
+  const startOffset = msg.Start.createStart(builder, 0 /* unused */);
+  const baseRes = sendSync(builder, msg.Any.Start, startOffset);
+  assert(baseRes != null);
+  assert(msg.Any.StartRes === baseRes!.innerType());
+  const startResMsg = new msg.StartRes();
+  assert(baseRes!.inner(startResMsg) != null);
+  return startResMsg;
 }
 
 // This function bootstraps an environment within Deno, it is shared both by
 // the runtime and the compiler environments.
 // @internal
-export function start(preserveDenoNamespace = true, source?: string): Start {
+export function start(
+  preserveDenoNamespace = true,
+  source?: string
+): msg.StartRes {
   core.setAsyncHandler(dispatch.asyncMsgFromRust);
 
   // First we send an empty `Start` message to let the privileged side know we
   // are ready. The response should be a `StartRes` message containing the CLI
   // args and other info.
-  const s = sendSync(dispatch.OP_START);
+  const startResMsg = sendStart();
 
-  util.setLogDebug(s.debugFlag, source);
+  util.setLogDebug(startResMsg.debugFlag(), source);
 
-  setGlobals(s.pid, s.noColor);
+  setGlobals(startResMsg.pid(), startResMsg.noColor());
 
   if (preserveDenoNamespace) {
     util.immutableDefine(window, "Deno", window.Deno);
@@ -100,7 +105,7 @@ export function start(preserveDenoNamespace = true, source?: string): Start {
     assert(window.Deno === undefined);
   }
 
-  return s;
+  return startResMsg;
 }
 
 /**
@@ -108,10 +113,18 @@ export function start(preserveDenoNamespace = true, source?: string): Start {
  * Requires the `--allow-env` flag.
  */
 export function homeDir(): string {
-  const path = sendSync(dispatch.OP_HOME_DIR);
+  const builder = flatbuffers.createBuilder();
+  const inner = msg.HomeDir.createHomeDir(builder);
+  const baseRes = sendSync(builder, msg.Any.HomeDir, inner)!;
+  assert(msg.Any.HomeDirRes === baseRes.innerType());
+  const res = new msg.HomeDirRes();
+  assert(baseRes.inner(res) != null);
+  const path = res.path();
+
   if (!path) {
     throw new Error("Could not get home directory.");
   }
+
   return path;
 }
 
@@ -120,5 +133,5 @@ export function homeDir(): string {
  * Requires the `--allow-env` flag.
  */
 export function execPath(): string {
-  return sendSync(dispatch.OP_EXEC_PATH);
+  return dispatchJson.sendSync(dispatch.OP_EXEC_PATH);
 }