1 files changed, 80 insertions, 0 deletions
diff --git a/cli/js/dispatch_minimal.ts b/cli/js/dispatch_minimal.ts
new file mode 100644
index 000000000..98636f85b
--- /dev/null
+++ b/cli/js/dispatch_minimal.ts
@@ -0,0 +1,80 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+import * as util from "./util.ts";
+import { core } from "./core.ts";
+
+const promiseTableMin = new Map<number, util.Resolvable<number>>();
+// Note it's important that promiseId starts at 1 instead of 0, because sync
+// messages are indicated with promiseId 0. If we ever add wrap around logic for
+// overflows, this should be taken into account.
+let _nextPromiseId = 1;
+
+function nextPromiseId(): number {
+  return _nextPromiseId++;
+}
+
+export interface RecordMinimal {
+  promiseId: number;
+  opId: number; // Maybe better called dispatchId
+  arg: number;
+  result: number;
+}
+
+export function recordFromBufMinimal(
+  opId: number,
+  buf32: Int32Array
+): RecordMinimal {
+  if (buf32.length != 3) {
+    throw Error("Bad message");
+  }
+  return {
+    promiseId: buf32[0],
+    opId,
+    arg: buf32[1],
+    result: buf32[2]
+  };
+}
+
+const scratch32 = new Int32Array(3);
+const scratchBytes = new Uint8Array(
+  scratch32.buffer,
+  scratch32.byteOffset,
+  scratch32.byteLength
+);
+util.assert(scratchBytes.byteLength === scratch32.length * 4);
+
+export function asyncMsgFromRust(opId: number, ui8: Uint8Array): void {
+  const buf32 = new Int32Array(ui8.buffer, ui8.byteOffset, ui8.byteLength / 4);
+  const record = recordFromBufMinimal(opId, buf32);
+  const { promiseId, result } = record;
+  const promise = promiseTableMin.get(promiseId);
+  promiseTableMin.delete(promiseId);
+  promise!.resolve(result);
+}
+
+export function sendAsyncMinimal(
+  opId: number,
+  arg: number,
+  zeroCopy: Uint8Array
+): Promise<number> {
+  const promiseId = nextPromiseId(); // AKA cmdId
+  scratch32[0] = promiseId;
+  scratch32[1] = arg;
+  scratch32[2] = 0; // result
+  const promise = util.createResolvable<number>();
+  promiseTableMin.set(promiseId, promise);
+  core.dispatch(opId, scratchBytes, zeroCopy);
+  return promise;
+}
+
+export function sendSyncMinimal(
+  opId: number,
+  arg: number,
+  zeroCopy: Uint8Array
+): number {
+  scratch32[0] = 0; // promiseId 0 indicates sync
+  scratch32[1] = arg;
+  const res = core.dispatch(opId, scratchBytes, zeroCopy)!;
+  const res32 = new Int32Array(res.buffer, res.byteOffset, 3);
+  const resRecord = recordFromBufMinimal(opId, res32);
+  return resRecord.result;
+}