chinwagsocial/app/javascript/mastodon/actions/statuses.js
Matt Panaro 31f7c3fc5d Summary: fix slowness due to layout thrashing when reloading a large … (#12661)
* Summary: fix slowness due to layout thrashing when reloading a large set of status updates

in order to limit the maximum size of a status in a list view (e.g. the home timeline), so as to avoid having to scroll all the way through an abnormally large status update (see https://github.com/tootsuite/mastodon/pull/8205), the following steps are taken:
•the element containing the status is rendered in the browser
•its height is calculated, to determine if it exceeds the maximum height threshold.
Unfortunately for performance, these steps are carried out in the componentDidMount(/Update) method, which also performs style modifications on the element.  The combination of  height request and style modification during javascript evaluation in the browser leads to layout-thrashing, where the elements are repeatedly re-laid-out (see https://developers.google.com/web/fundamentals/performance/rendering/avoid-large-complex-layouts-and-layout-thrashing & https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Performance_best_practices_for_Firefox_fe_engineers).
The solution implemented here is to memoize the collapsed state in Redux the first time the status is seen (e.g. when fetched as part of a small batch, to populate the home timeline) , so that on subsequent re-renders, the value can be queried, rather than recalculated.  This strategy is derived from https://github.com/tootsuite/mastodon/pull/4439 & https://github.com/tootsuite/mastodon/pull/4909, and should resolve https://github.com/tootsuite/mastodon/issues/12455.

Andrew Lin (https://github.com/onethreeseven) is thanked for his assistance in root cause analysis and solution brainstorming

* remove getSnapshotBeforeUpdate from status

* remove componentWillUnmount from status

* persist last-intersected status update and restore when ScrollableList is restored

e.g. when navigating from home-timeline to a status conversational  thread and <Back again

* cache currently-viewing status id to avoid calling redux with identical value

* refactor collapse toggle to pass explicit boolean
2019-12-29 05:39:48 +01:00

331 lines
7.7 KiB
JavaScript

import api from '../api';
import openDB from '../storage/db';
import { evictStatus } from '../storage/modifier';
import { deleteFromTimelines } from './timelines';
import { importFetchedStatus, importFetchedStatuses, importAccount, importStatus } from './importer';
import { ensureComposeIsVisible } from './compose';
export const STATUS_FETCH_REQUEST = 'STATUS_FETCH_REQUEST';
export const STATUS_FETCH_SUCCESS = 'STATUS_FETCH_SUCCESS';
export const STATUS_FETCH_FAIL = 'STATUS_FETCH_FAIL';
export const STATUS_DELETE_REQUEST = 'STATUS_DELETE_REQUEST';
export const STATUS_DELETE_SUCCESS = 'STATUS_DELETE_SUCCESS';
export const STATUS_DELETE_FAIL = 'STATUS_DELETE_FAIL';
export const CONTEXT_FETCH_REQUEST = 'CONTEXT_FETCH_REQUEST';
export const CONTEXT_FETCH_SUCCESS = 'CONTEXT_FETCH_SUCCESS';
export const CONTEXT_FETCH_FAIL = 'CONTEXT_FETCH_FAIL';
export const STATUS_MUTE_REQUEST = 'STATUS_MUTE_REQUEST';
export const STATUS_MUTE_SUCCESS = 'STATUS_MUTE_SUCCESS';
export const STATUS_MUTE_FAIL = 'STATUS_MUTE_FAIL';
export const STATUS_UNMUTE_REQUEST = 'STATUS_UNMUTE_REQUEST';
export const STATUS_UNMUTE_SUCCESS = 'STATUS_UNMUTE_SUCCESS';
export const STATUS_UNMUTE_FAIL = 'STATUS_UNMUTE_FAIL';
export const STATUS_REVEAL = 'STATUS_REVEAL';
export const STATUS_HIDE = 'STATUS_HIDE';
export const STATUS_COLLAPSE = 'STATUS_COLLAPSE';
export const REDRAFT = 'REDRAFT';
export function fetchStatusRequest(id, skipLoading) {
return {
type: STATUS_FETCH_REQUEST,
id,
skipLoading,
};
};
function getFromDB(dispatch, getState, accountIndex, index, id) {
return new Promise((resolve, reject) => {
const request = index.get(id);
request.onerror = reject;
request.onsuccess = () => {
const promises = [];
if (!request.result) {
reject();
return;
}
dispatch(importStatus(request.result));
if (getState().getIn(['accounts', request.result.account], null) === null) {
promises.push(new Promise((accountResolve, accountReject) => {
const accountRequest = accountIndex.get(request.result.account);
accountRequest.onerror = accountReject;
accountRequest.onsuccess = () => {
if (!request.result) {
accountReject();
return;
}
dispatch(importAccount(accountRequest.result));
accountResolve();
};
}));
}
if (request.result.reblog && getState().getIn(['statuses', request.result.reblog], null) === null) {
promises.push(getFromDB(dispatch, getState, accountIndex, index, request.result.reblog));
}
resolve(Promise.all(promises));
};
});
}
export function fetchStatus(id) {
return (dispatch, getState) => {
const skipLoading = getState().getIn(['statuses', id], null) !== null;
dispatch(fetchContext(id));
if (skipLoading) {
return;
}
dispatch(fetchStatusRequest(id, skipLoading));
openDB().then(db => {
const transaction = db.transaction(['accounts', 'statuses'], 'read');
const accountIndex = transaction.objectStore('accounts').index('id');
const index = transaction.objectStore('statuses').index('id');
return getFromDB(dispatch, getState, accountIndex, index, id).then(() => {
db.close();
}, error => {
db.close();
throw error;
});
}).then(() => {
dispatch(fetchStatusSuccess(skipLoading));
}, () => api(getState).get(`/api/v1/statuses/${id}`).then(response => {
dispatch(importFetchedStatus(response.data));
dispatch(fetchStatusSuccess(skipLoading));
})).catch(error => {
dispatch(fetchStatusFail(id, error, skipLoading));
});
};
};
export function fetchStatusSuccess(skipLoading) {
return {
type: STATUS_FETCH_SUCCESS,
skipLoading,
};
};
export function fetchStatusFail(id, error, skipLoading) {
return {
type: STATUS_FETCH_FAIL,
id,
error,
skipLoading,
skipAlert: true,
};
};
export function redraft(status, raw_text) {
return {
type: REDRAFT,
status,
raw_text,
};
};
export function deleteStatus(id, routerHistory, withRedraft = false) {
return (dispatch, getState) => {
let status = getState().getIn(['statuses', id]);
if (status.get('poll')) {
status = status.set('poll', getState().getIn(['polls', status.get('poll')]));
}
dispatch(deleteStatusRequest(id));
api(getState).delete(`/api/v1/statuses/${id}`).then(response => {
evictStatus(id);
dispatch(deleteStatusSuccess(id));
dispatch(deleteFromTimelines(id));
if (withRedraft) {
dispatch(redraft(status, response.data.text));
ensureComposeIsVisible(getState, routerHistory);
}
}).catch(error => {
dispatch(deleteStatusFail(id, error));
});
};
};
export function deleteStatusRequest(id) {
return {
type: STATUS_DELETE_REQUEST,
id: id,
};
};
export function deleteStatusSuccess(id) {
return {
type: STATUS_DELETE_SUCCESS,
id: id,
};
};
export function deleteStatusFail(id, error) {
return {
type: STATUS_DELETE_FAIL,
id: id,
error: error,
};
};
export function fetchContext(id) {
return (dispatch, getState) => {
dispatch(fetchContextRequest(id));
api(getState).get(`/api/v1/statuses/${id}/context`).then(response => {
dispatch(importFetchedStatuses(response.data.ancestors.concat(response.data.descendants)));
dispatch(fetchContextSuccess(id, response.data.ancestors, response.data.descendants));
}).catch(error => {
if (error.response && error.response.status === 404) {
dispatch(deleteFromTimelines(id));
}
dispatch(fetchContextFail(id, error));
});
};
};
export function fetchContextRequest(id) {
return {
type: CONTEXT_FETCH_REQUEST,
id,
};
};
export function fetchContextSuccess(id, ancestors, descendants) {
return {
type: CONTEXT_FETCH_SUCCESS,
id,
ancestors,
descendants,
statuses: ancestors.concat(descendants),
};
};
export function fetchContextFail(id, error) {
return {
type: CONTEXT_FETCH_FAIL,
id,
error,
skipAlert: true,
};
};
export function muteStatus(id) {
return (dispatch, getState) => {
dispatch(muteStatusRequest(id));
api(getState).post(`/api/v1/statuses/${id}/mute`).then(() => {
dispatch(muteStatusSuccess(id));
}).catch(error => {
dispatch(muteStatusFail(id, error));
});
};
};
export function muteStatusRequest(id) {
return {
type: STATUS_MUTE_REQUEST,
id,
};
};
export function muteStatusSuccess(id) {
return {
type: STATUS_MUTE_SUCCESS,
id,
};
};
export function muteStatusFail(id, error) {
return {
type: STATUS_MUTE_FAIL,
id,
error,
};
};
export function unmuteStatus(id) {
return (dispatch, getState) => {
dispatch(unmuteStatusRequest(id));
api(getState).post(`/api/v1/statuses/${id}/unmute`).then(() => {
dispatch(unmuteStatusSuccess(id));
}).catch(error => {
dispatch(unmuteStatusFail(id, error));
});
};
};
export function unmuteStatusRequest(id) {
return {
type: STATUS_UNMUTE_REQUEST,
id,
};
};
export function unmuteStatusSuccess(id) {
return {
type: STATUS_UNMUTE_SUCCESS,
id,
};
};
export function unmuteStatusFail(id, error) {
return {
type: STATUS_UNMUTE_FAIL,
id,
error,
};
};
export function hideStatus(ids) {
if (!Array.isArray(ids)) {
ids = [ids];
}
return {
type: STATUS_HIDE,
ids,
};
};
export function revealStatus(ids) {
if (!Array.isArray(ids)) {
ids = [ids];
}
return {
type: STATUS_REVEAL,
ids,
};
};
export function toggleStatusCollapse(id, isCollapsed) {
return {
type: STATUS_COLLAPSE,
id,
isCollapsed,
};
}