next
Version:
The React Framework
107 lines (106 loc) • 4.32 kB
JavaScript
/**
* This is the default "use cache" handler it defaults to an in-memory store.
* In-memory caches are fragile and should not use stale-while-revalidate
* semantics on the caches because it's not worth warming up an entry that's
* likely going to get evicted before we get to use it anyway. However, we also
* don't want to reuse a stale entry for too long so stale entries should be
* considered expired/missing in such cache handlers.
*/ import { LRUCache } from '../lru-cache';
import { isStale, tagsManifest } from '../incremental-cache/tags-manifest.external';
// LRU cache default to max 50 MB but in future track
const memoryCache = new LRUCache(50 * 1024 * 1024, (entry)=>entry.size);
const pendingSets = new Map();
const debug = process.env.NEXT_PRIVATE_DEBUG_CACHE ? console.debug.bind(console, 'DefaultCacheHandler:') : undefined;
const DefaultCacheHandler = {
async get (cacheKey) {
const pendingPromise = pendingSets.get(cacheKey);
if (pendingPromise) {
debug == null ? void 0 : debug('get', cacheKey, 'pending');
await pendingPromise;
}
const privateEntry = memoryCache.get(cacheKey);
if (!privateEntry) {
debug == null ? void 0 : debug('get', cacheKey, 'not found');
return undefined;
}
const entry = privateEntry.entry;
if (performance.timeOrigin + performance.now() > entry.timestamp + entry.revalidate * 1000) {
// In-memory caches should expire after revalidate time because it is
// unlikely that a new entry will be able to be used before it is dropped
// from the cache.
debug == null ? void 0 : debug('get', cacheKey, 'expired');
return undefined;
}
if (isStale(entry.tags, entry.timestamp)) {
debug == null ? void 0 : debug('get', cacheKey, 'had stale tag');
return undefined;
}
const [returnStream, newSaved] = entry.value.tee();
entry.value = newSaved;
debug == null ? void 0 : debug('get', cacheKey, 'found', {
tags: entry.tags,
timestamp: entry.timestamp,
revalidate: entry.revalidate,
expire: entry.expire
});
return {
...entry,
value: returnStream
};
},
async set (cacheKey, pendingEntry) {
debug == null ? void 0 : debug('set', cacheKey, 'start');
let resolvePending = ()=>{};
const pendingPromise = new Promise((resolve)=>{
resolvePending = resolve;
});
pendingSets.set(cacheKey, pendingPromise);
const entry = await pendingEntry;
let size = 0;
try {
const [value, clonedValue] = entry.value.tee();
entry.value = value;
const reader = clonedValue.getReader();
for(let chunk; !(chunk = await reader.read()).done;){
size += Buffer.from(chunk.value).byteLength;
}
memoryCache.set(cacheKey, {
entry,
isErrored: false,
errorRetryCount: 0,
size
});
debug == null ? void 0 : debug('set', cacheKey, 'done');
} catch (err) {
// TODO: store partial buffer with error after we retry 3 times
debug == null ? void 0 : debug('set', cacheKey, 'failed', err);
} finally{
resolvePending();
pendingSets.delete(cacheKey);
}
},
async refreshTags () {
// Nothing to do for an in-memory cache handler.
},
async getExpiration (...tags) {
const expiration = Math.max(...tags.map((tag)=>tagsManifest.get(tag) ?? 0));
debug == null ? void 0 : debug('getExpiration', {
tags,
expiration
});
return expiration;
},
async expireTags (...tags) {
const timestamp = Math.round(performance.timeOrigin + performance.now());
debug == null ? void 0 : debug('expireTags', {
tags,
timestamp
});
for (const tag of tags){
// TODO: update file-system-cache?
tagsManifest.set(tag, timestamp);
}
}
};
export default DefaultCacheHandler;
//# sourceMappingURL=default.js.map