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// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
((window) => {
const core = window.Deno.core;
const util = window.__bootstrap.util;
// Using an object without a prototype because `Map` was causing GC problems.
const promiseTableMin = Object.create(null);
const decoder = new TextDecoder();
// 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() {
return _nextPromiseId++;
}
function recordFromBufMinimal(ui8) {
const headerLen = 12;
const header = ui8.subarray(0, headerLen);
const buf32 = new Int32Array(
header.buffer,
header.byteOffset,
header.byteLength / 4,
);
const promiseId = buf32[0];
const arg = buf32[1];
const result = buf32[2];
let err;
if (arg < 0) {
err = {
className: decoder.decode(ui8.subarray(headerLen, headerLen + result)),
message: decoder.decode(ui8.subarray(headerLen + result)),
};
} else if (ui8.length != 12) {
throw new TypeError("Malformed response message");
}
return {
promiseId,
arg,
result,
err,
};
}
function unwrapResponse(res) {
if (res.err != null) {
const ErrorClass = core.getErrorClass(res.err.className);
if (!ErrorClass) {
throw new Error(
`Unregistered error class: "${res.err.className}"\n ${res.err.message}\n Classes of errors returned from ops should be registered via Deno.core.registerErrorClass().`,
);
}
throw new ErrorClass(res.err.message);
}
return res.result;
}
const scratch32 = new Int32Array(3);
const scratchBytes = new Uint8Array(
scratch32.buffer,
scratch32.byteOffset,
scratch32.byteLength,
);
util.assert(scratchBytes.byteLength === scratch32.length * 4);
function asyncMsgFromRust(ui8) {
const record = recordFromBufMinimal(ui8);
const { promiseId } = record;
const promise = promiseTableMin[promiseId];
delete promiseTableMin[promiseId];
util.assert(promise);
promise.resolve(record);
}
async function sendAsync(opName, arg, zeroCopy) {
const promiseId = nextPromiseId(); // AKA cmdId
scratch32[0] = promiseId;
scratch32[1] = arg;
scratch32[2] = 0; // result
const promise = util.createResolvable();
const buf = core.dispatchByName(opName, scratchBytes, zeroCopy);
if (buf != null) {
const record = recordFromBufMinimal(buf);
// Sync result.
promise.resolve(record);
} else {
// Async result.
promiseTableMin[promiseId] = promise;
}
const res = await promise;
return unwrapResponse(res);
}
function sendSync(opName, arg, zeroCopy) {
scratch32[0] = 0; // promiseId 0 indicates sync
scratch32[1] = arg;
const res = core.dispatchByName(opName, scratchBytes, zeroCopy);
const resRecord = recordFromBufMinimal(res);
return unwrapResponse(resRecord);
}
window.__bootstrap.dispatchMinimal = {
asyncMsgFromRust,
sendSync,
sendAsync,
};
})(this);
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