core: add Deno.core.dispatchByName (#6395)

This commit adds alternate dispatch method to core JS API.

"Deno.core.dispatchByName()" works like "Deno.core.dispatch()", 
but takes op name instead of op id as a first argument.

1 files changed, 4 insertions, 23 deletions

diff --git a/cli/js/ops/io.ts b/cli/js/ops/io.ts
index b4ef837e0..cc3d1d170 100644
--- a/cli/js/ops/io.ts
+++ b/cli/js/ops/io.ts
@@ -1,22 +1,12 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 
 import { sendAsyncMinimal, sendSyncMinimal } from "./dispatch_minimal.ts";
-// TODO(bartlomieju): remove this import and maybe lazy-initialize
-// OPS_CACHE that belongs only to this module
-import { OPS_CACHE } from "../runtime.ts";
-
-// This is done because read/write are extremely performance sensitive.
-let OP_READ = -1;
-let OP_WRITE = -1;
 
 export function readSync(rid: number, buffer: Uint8Array): number | null {
   if (buffer.length == 0) {
     return 0;
   }
-  if (OP_READ < 0) {
-    OP_READ = OPS_CACHE["op_read"];
-  }
-  const nread = sendSyncMinimal(OP_READ, rid, buffer);
+  const nread = sendSyncMinimal("op_read", rid, buffer);
   if (nread < 0) {
     throw new Error("read error");
   } else if (nread == 0) {
@@ -33,10 +23,7 @@ export async function read(
   if (buffer.length == 0) {
     return 0;
   }
-  if (OP_READ < 0) {
-    OP_READ = OPS_CACHE["op_read"];
-  }
-  const nread = await sendAsyncMinimal(OP_READ, rid, buffer);
+  const nread = await sendAsyncMinimal("op_read", rid, buffer);
   if (nread < 0) {
     throw new Error("read error");
   } else if (nread == 0) {
@@ -47,10 +34,7 @@ export async function read(
 }
 
 export function writeSync(rid: number, data: Uint8Array): number {
-  if (OP_WRITE < 0) {
-    OP_WRITE = OPS_CACHE["op_write"];
-  }
-  const result = sendSyncMinimal(OP_WRITE, rid, data);
+  const result = sendSyncMinimal("op_write", rid, data);
   if (result < 0) {
     throw new Error("write error");
   } else {
@@ -59,10 +43,7 @@ export function writeSync(rid: number, data: Uint8Array): number {
 }
 
 export async function write(rid: number, data: Uint8Array): Promise<number> {
-  if (OP_WRITE < 0) {
-    OP_WRITE = OPS_CACHE["op_write"];
-  }
-  const result = await sendAsyncMinimal(OP_WRITE, rid, data);
+  const result = await sendAsyncMinimal("op_write", rid, data);
   if (result < 0) {
     throw new Error("write error");
   } else {