Files
scrap/node_modules/next/dist/esm/server/web/spec-extension/unstable-cache.js
2024-09-24 03:52:46 +00:00

217 lines
13 KiB
JavaScript

import { CACHE_ONE_YEAR } from "../../../lib/constants";
import { addImplicitTags, validateRevalidate, validateTags } from "../../lib/patch-fetch";
import { staticGenerationAsyncStorage } from "../../../client/components/static-generation-async-storage.external";
let noStoreFetchIdx = 0;
async function cacheNewResult(result, incrementalCache, cacheKey, tags, revalidate, fetchIdx, fetchUrl) {
await incrementalCache.set(cacheKey, {
kind: "FETCH",
data: {
headers: {},
// TODO: handle non-JSON values?
body: JSON.stringify(result),
status: 200,
url: ""
},
revalidate: typeof revalidate !== "number" ? CACHE_ONE_YEAR : revalidate
}, {
revalidate,
fetchCache: true,
tags,
fetchIdx,
fetchUrl
});
return;
}
/**
* This function allows you to cache the results of expensive operations, like database queries, and reuse them across multiple requests.
*
* Read more: [Next.js Docs: `unstable_cache`](https://nextjs.org/docs/app/api-reference/functions/unstable_cache)
*/ export function unstable_cache(cb, keyParts, options = {}) {
if (options.revalidate === 0) {
throw new Error(`Invariant revalidate: 0 can not be passed to unstable_cache(), must be "false" or "> 0" ${cb.toString()}`);
}
// Validate the tags provided are valid
const tags = options.tags ? validateTags(options.tags, `unstable_cache ${cb.toString()}`) : [];
// Validate the revalidate options
validateRevalidate(options.revalidate, `unstable_cache ${cb.name || cb.toString()}`);
// Stash the fixed part of the key at construction time. The invocation key will combine
// the fixed key with the arguments when actually called
// @TODO if cb.toString() is long we should hash it
// @TODO come up with a collision-free way to combine keyParts
// @TODO consider validating the keyParts are all strings. TS can't provide runtime guarantees
// and the error produced by accidentally using something that cannot be safely coerced is likely
// hard to debug
const fixedKey = `${cb.toString()}-${Array.isArray(keyParts) && keyParts.join(",")}`;
const cachedCb = async (...args)=>{
const store = staticGenerationAsyncStorage.getStore();
// We must be able to find the incremental cache otherwise we throw
const maybeIncrementalCache = (store == null ? void 0 : store.incrementalCache) || globalThis.__incrementalCache;
if (!maybeIncrementalCache) {
throw new Error(`Invariant: incrementalCache missing in unstable_cache ${cb.toString()}`);
}
const incrementalCache = maybeIncrementalCache;
const { pathname, searchParams } = new URL((store == null ? void 0 : store.urlPathname) || "/", "http://n");
const sortedSearchKeys = [
...searchParams.keys()
].sort((a, b)=>{
return a.localeCompare(b);
});
const sortedSearch = sortedSearchKeys.map((key)=>`${key}=${searchParams.get(key)}`).join("&");
// Construct the complete cache key for this function invocation
// @TODO stringify is likely not safe here. We will coerce undefined to null which will make
// the keyspace smaller than the execution space
const invocationKey = `${fixedKey}-${JSON.stringify(args)}`;
const cacheKey = await incrementalCache.fetchCacheKey(invocationKey);
// $urlWithPath,$sortedQueryStringKeys,$hashOfEveryThingElse
const fetchUrl = `unstable_cache ${pathname}${sortedSearch.length ? "?" : ""}${sortedSearch} ${cb.name ? ` ${cb.name}` : cacheKey}`;
const fetchIdx = (store ? store.nextFetchId : noStoreFetchIdx) ?? 1;
if (store) {
store.nextFetchId = fetchIdx + 1;
// We are in an App Router context. We try to return the cached entry if it exists and is valid
// If the entry is fresh we return it. If the entry is stale we return it but revalidate the entry in
// the background. If the entry is missing or invalid we generate a new entry and return it.
// We update the store's revalidate property if the option.revalidate is a higher precedence
if (typeof options.revalidate === "number") {
if (typeof store.revalidate === "number" && store.revalidate < options.revalidate) {
// The store is already revalidating on a shorter time interval, leave it alone
} else {
store.revalidate = options.revalidate;
}
} else if (options.revalidate === false && typeof store.revalidate === "undefined") {
// The store has not defined revalidate type so we can use the false option
store.revalidate = options.revalidate;
}
// We need to accumulate the tags for this invocation within the store
if (!store.tags) {
store.tags = tags.slice();
} else {
for (const tag of tags){
// @TODO refactor tags to be a set to avoid this O(n) lookup
if (!store.tags.includes(tag)) {
store.tags.push(tag);
}
}
}
// @TODO check on this API. addImplicitTags mutates the store and returns the implicit tags. The naming
// of this function is potentially a little confusing
const implicitTags = addImplicitTags(store);
if (// when we are nested inside of other unstable_cache's
// we should bypass cache similar to fetches
store.fetchCache !== "force-no-store" && !store.isOnDemandRevalidate && !incrementalCache.isOnDemandRevalidate && !store.isDraftMode) {
// We attempt to get the current cache entry from the incremental cache.
const cacheEntry = await incrementalCache.get(cacheKey, {
kindHint: "fetch",
revalidate: options.revalidate,
tags,
softTags: implicitTags,
fetchIdx,
fetchUrl
});
if (cacheEntry && cacheEntry.value) {
// The entry exists and has a value
if (cacheEntry.value.kind !== "FETCH") {
// The entry is invalid and we need a special warning
// @TODO why do we warn this way? Should this just be an error? How are these errors surfaced
// so bugs can be reported
// @TODO the invocation key can have sensitive data in it. we should not log this entire object
console.error(`Invariant invalid cacheEntry returned for ${invocationKey}`);
// will fall through to generating a new cache entry below
} else {
// We have a valid cache entry so we will be returning it. We also check to see if we need
// to background revalidate it by checking if it is stale.
const cachedResponse = cacheEntry.value.data.body !== undefined ? JSON.parse(cacheEntry.value.data.body) : undefined;
if (cacheEntry.isStale) {
// In App Router we return the stale result and revalidate in the background
if (!store.pendingRevalidates) {
store.pendingRevalidates = {};
}
// We run the cache function asynchronously and save the result when it completes
store.pendingRevalidates[invocationKey] = staticGenerationAsyncStorage.run({
...store,
// force any nested fetches to bypass cache so they revalidate
// when the unstable_cache call is revalidated
fetchCache: "force-no-store",
isUnstableCacheCallback: true
}, cb, ...args).then((result)=>{
return cacheNewResult(result, incrementalCache, cacheKey, tags, options.revalidate, fetchIdx, fetchUrl);
})// @TODO This error handling seems wrong. We swallow the error?
.catch((err)=>console.error(`revalidating cache with key: ${invocationKey}`, err));
}
// We had a valid cache entry so we return it here
return cachedResponse;
}
}
}
// If we got this far then we had an invalid cache entry and need to generate a new one
const result = await staticGenerationAsyncStorage.run({
...store,
// force any nested fetches to bypass cache so they revalidate
// when the unstable_cache call is revalidated
fetchCache: "force-no-store",
isUnstableCacheCallback: true
}, cb, ...args);
if (!store.isDraftMode) {
cacheNewResult(result, incrementalCache, cacheKey, tags, options.revalidate, fetchIdx, fetchUrl);
}
return result;
} else {
noStoreFetchIdx += 1;
// We are in Pages Router or were called outside of a render. We don't have a store
// so we just call the callback directly when it needs to run.
// If the entry is fresh we return it. If the entry is stale we return it but revalidate the entry in
// the background. If the entry is missing or invalid we generate a new entry and return it.
if (!incrementalCache.isOnDemandRevalidate) {
// We aren't doing an on demand revalidation so we check use the cache if valid
// @TODO check on this API. addImplicitTags mutates the store and returns the implicit tags. The naming
// of this function is potentially a little confusing
const implicitTags = store && addImplicitTags(store);
const cacheEntry = await incrementalCache.get(cacheKey, {
kindHint: "fetch",
revalidate: options.revalidate,
tags,
fetchIdx,
fetchUrl,
softTags: implicitTags
});
if (cacheEntry && cacheEntry.value) {
// The entry exists and has a value
if (cacheEntry.value.kind !== "FETCH") {
// The entry is invalid and we need a special warning
// @TODO why do we warn this way? Should this just be an error? How are these errors surfaced
// so bugs can be reported
console.error(`Invariant invalid cacheEntry returned for ${invocationKey}`);
// will fall through to generating a new cache entry below
} else if (!cacheEntry.isStale) {
// We have a valid cache entry and it is fresh so we return it
return cacheEntry.value.data.body !== undefined ? JSON.parse(cacheEntry.value.data.body) : undefined;
}
}
}
// If we got this far then we had an invalid cache entry and need to generate a new one
// @TODO this storage wrapper is included here because it existed prior to the latest refactor
// however it is incorrect logic because it causes any internal cache calls to follow the App Router
// path rather than Pages router path. This may mean there is existing buggy behavior however no specific
// issues are known at this time. The whole static generation storage pathways should be reworked
// to allow tracking which "mode" we are in without the presence of a store or not. For now I have
// maintained the existing behavior to limit the impact of the current refactor
const result = await staticGenerationAsyncStorage.run(// We are making a fake store that is useful for scoping fetchCache: 'force-no-store' and isUnstableCacheCallback: true
// The fact that we need to construct this kind of fake store indicates the code is not factored correctly
// @TODO refactor to not require this fake store object
{
// force any nested fetches to bypass cache so they revalidate
// when the unstable_cache call is revalidated
fetchCache: "force-no-store",
isUnstableCacheCallback: true,
urlPathname: "/",
isStaticGeneration: false,
prerenderState: null
}, cb, ...args);
cacheNewResult(result, incrementalCache, cacheKey, tags, options.revalidate, fetchIdx, fetchUrl);
return result;
}
};
// TODO: once AsyncLocalStorage.run() returns the correct types this override will no longer be necessary
return cachedCb;
}
//# sourceMappingURL=unstable-cache.js.map