79 lines
2.3 KiB
JavaScript
79 lines
2.3 KiB
JavaScript
function ItoI(a) {
|
|
return a;
|
|
}
|
|
function innerCreateMedium(defaults, middleware = ItoI) {
|
|
let buffer = [];
|
|
let assigned = false;
|
|
const medium = {
|
|
read() {
|
|
if (assigned) {
|
|
throw new Error('Sidecar: could not `read` from an `assigned` medium. `read` could be used only with `useMedium`.');
|
|
}
|
|
if (buffer.length) {
|
|
return buffer[buffer.length - 1];
|
|
}
|
|
return defaults;
|
|
},
|
|
useMedium(data) {
|
|
const item = middleware(data, assigned);
|
|
buffer.push(item);
|
|
return () => {
|
|
buffer = buffer.filter((x) => x !== item);
|
|
};
|
|
},
|
|
assignSyncMedium(cb) {
|
|
assigned = true;
|
|
while (buffer.length) {
|
|
const cbs = buffer;
|
|
buffer = [];
|
|
cbs.forEach(cb);
|
|
}
|
|
buffer = {
|
|
push: (x) => cb(x),
|
|
filter: () => buffer,
|
|
};
|
|
},
|
|
assignMedium(cb) {
|
|
assigned = true;
|
|
let pendingQueue = [];
|
|
if (buffer.length) {
|
|
const cbs = buffer;
|
|
buffer = [];
|
|
cbs.forEach(cb);
|
|
pendingQueue = buffer;
|
|
}
|
|
const executeQueue = () => {
|
|
const cbs = pendingQueue;
|
|
pendingQueue = [];
|
|
cbs.forEach(cb);
|
|
};
|
|
const cycle = () => Promise.resolve().then(executeQueue);
|
|
cycle();
|
|
buffer = {
|
|
push: (x) => {
|
|
pendingQueue.push(x);
|
|
cycle();
|
|
},
|
|
filter: (filter) => {
|
|
pendingQueue = pendingQueue.filter(filter);
|
|
return buffer;
|
|
},
|
|
};
|
|
},
|
|
};
|
|
return medium;
|
|
}
|
|
export function createMedium(defaults, middleware = ItoI) {
|
|
return innerCreateMedium(defaults, middleware);
|
|
}
|
|
// eslint-disable-next-line @typescript-eslint/ban-types
|
|
export function createSidecarMedium(options = {}) {
|
|
const medium = innerCreateMedium(null);
|
|
medium.options = {
|
|
async: true,
|
|
ssr: false,
|
|
...options,
|
|
};
|
|
return medium;
|
|
}
|