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denoland-deno/cli/js/dispatch_minimal.ts
2019-10-14 17:46:27 -04:00

92 lines
2.5 KiB
TypeScript

// 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>();
const buf = core.dispatch(opId, scratchBytes, zeroCopy);
if (buf) {
const buf32 = new Int32Array(
buf.buffer,
buf.byteOffset,
buf.byteLength / 4
);
const record = recordFromBufMinimal(opId, buf32);
// Sync result.
promise.resolve(record.result);
} else {
// Async result.
promiseTableMin.set(promiseId, promise);
}
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;
}