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"use strict"; Object.defineProperty(exports, "__esModule", { value: true }); 0 && (module.exports = { EntryStatus: null, FetchStrategy: null, convertRouteTreeToFlightRouterState: null, createDetachedSegmentCacheEntry: null, fetchRouteOnCacheMiss: null, fetchSegmentOnCacheMiss: null, fetchSegmentPrefetchesUsingDynamicRequest: null, getCurrentCacheVersion: null, getSegmentKeypathForTask: null, readExactRouteCacheEntry: null, readOrCreateRevalidatingSegmentEntry: null, readOrCreateRouteCacheEntry: null, readOrCreateSegmentCacheEntry: null, readRouteCacheEntry: null, readSegmentCacheEntry: null, resetRevalidatingSegmentEntry: null, revalidateEntireCache: null, upgradeToPendingSegment: null, upsertSegmentEntry: null, waitForSegmentCacheEntry: null }); function _export(target, all) { for(var name in all)Object.defineProperty(target, name, { enumerable: true, get: all[name] }); } _export(exports, { EntryStatus: function() { return EntryStatus; }, FetchStrategy: function() { return FetchStrategy; }, convertRouteTreeToFlightRouterState: function() { return convertRouteTreeToFlightRouterState; }, createDetachedSegmentCacheEntry: function() { return createDetachedSegmentCacheEntry; }, fetchRouteOnCacheMiss: function() { return fetchRouteOnCacheMiss; }, fetchSegmentOnCacheMiss: function() { return fetchSegmentOnCacheMiss; }, fetchSegmentPrefetchesUsingDynamicRequest: function() { return fetchSegmentPrefetchesUsingDynamicRequest; }, getCurrentCacheVersion: function() { return getCurrentCacheVersion; }, getSegmentKeypathForTask: function() { return getSegmentKeypathForTask; }, readExactRouteCacheEntry: function() { return readExactRouteCacheEntry; }, readOrCreateRevalidatingSegmentEntry: function() { return readOrCreateRevalidatingSegmentEntry; }, readOrCreateRouteCacheEntry: function() { return readOrCreateRouteCacheEntry; }, readOrCreateSegmentCacheEntry: function() { return readOrCreateSegmentCacheEntry; }, readRouteCacheEntry: function() { return readRouteCacheEntry; }, readSegmentCacheEntry: function() { return readSegmentCacheEntry; }, resetRevalidatingSegmentEntry: function() { return resetRevalidatingSegmentEntry; }, revalidateEntireCache: function() { return revalidateEntireCache; }, upgradeToPendingSegment: function() { return upgradeToPendingSegment; }, upsertSegmentEntry: function() { return upsertSegmentEntry; }, waitForSegmentCacheEntry: function() { return waitForSegmentCacheEntry; } }); const _approuterheaders = require("../app-router-headers"); const _fetchserverresponse = require("../router-reducer/fetch-server-response"); const _scheduler = require("./scheduler"); const _appbuildid = require("../../app-build-id"); const _createhreffromurl = require("../router-reducer/create-href-from-url"); const _tuplemap = require("./tuple-map"); const _lru = require("./lru"); const _segmentvalueencoding = require("../../../shared/lib/segment-cache/segment-value-encoding"); const _flightdatahelpers = require("../../flight-data-helpers"); const _prefetchcacheutils = require("../router-reducer/prefetch-cache-utils"); const _links = require("../links"); const _segment = require("../../../shared/lib/segment"); var EntryStatus = /*#__PURE__*/ function(EntryStatus) { EntryStatus[EntryStatus["Empty"] = 0] = "Empty"; EntryStatus[EntryStatus["Pending"] = 1] = "Pending"; EntryStatus[EntryStatus["Fulfilled"] = 2] = "Fulfilled"; EntryStatus[EntryStatus["Rejected"] = 3] = "Rejected"; return EntryStatus; }({}); var FetchStrategy = /*#__PURE__*/ function(FetchStrategy) { FetchStrategy[FetchStrategy["PPR"] = 0] = "PPR"; FetchStrategy[FetchStrategy["Full"] = 1] = "Full"; FetchStrategy[FetchStrategy["LoadingBoundary"] = 2] = "LoadingBoundary"; return FetchStrategy; }({}); const isOutputExportMode = process.env.NODE_ENV === 'production' && process.env.__NEXT_CONFIG_OUTPUT === 'export'; let routeCacheMap = (0, _tuplemap.createTupleMap)(); // We use an LRU for memory management. We must update this whenever we add or // remove a new cache entry, or when an entry changes size. // TODO: I chose the max size somewhat arbitrarily. Consider setting this based // on navigator.deviceMemory, or some other heuristic. We should make this // customizable via the Next.js config, too. const maxRouteLruSize = 10 * 1024 * 1024 // 10 MB ; let routeCacheLru = (0, _lru.createLRU)(maxRouteLruSize, onRouteLRUEviction); let segmentCacheMap = (0, _tuplemap.createTupleMap)(); // NOTE: Segments and Route entries are managed by separate LRUs. We could // combine them into a single LRU, but because they are separate types, we'd // need to wrap each one in an extra LRU node (to maintain monomorphism, at the // cost of additional memory). const maxSegmentLruSize = 50 * 1024 * 1024 // 50 MB ; let segmentCacheLru = (0, _lru.createLRU)(maxSegmentLruSize, onSegmentLRUEviction); // Incrementing counter used to track cache invalidations. let currentCacheVersion = 0; function getCurrentCacheVersion() { return currentCacheVersion; } function revalidateEntireCache(nextUrl, tree) { currentCacheVersion++; // Clearing the cache also effectively rejects any pending requests, because // when the response is received, it gets written into a cache entry that is // no longer reachable. // TODO: There's an exception to this case that we don't currently handle // correctly: background revalidations. See note in `upsertSegmentEntry`. routeCacheMap = (0, _tuplemap.createTupleMap)(); routeCacheLru = (0, _lru.createLRU)(maxRouteLruSize, onRouteLRUEviction); segmentCacheMap = (0, _tuplemap.createTupleMap)(); segmentCacheLru = (0, _lru.createLRU)(maxSegmentLruSize, onSegmentLRUEviction); // Prefetch all the currently visible links again, to re-fill the cache. (0, _links.pingVisibleLinks)(nextUrl, tree); } function readExactRouteCacheEntry(now, href, nextUrl) { const keypath = nextUrl === null ? [ href ] : [ href, nextUrl ]; const existingEntry = routeCacheMap.get(keypath); if (existingEntry !== null) { // Check if the entry is stale if (existingEntry.staleAt > now) { // Reuse the existing entry. // Since this is an access, move the entry to the front of the LRU. routeCacheLru.put(existingEntry); return existingEntry; } else { // Evict the stale entry from the cache. deleteRouteFromCache(existingEntry, keypath); } } return null; } function readRouteCacheEntry(now, key) { // First check if there's a non-intercepted entry. Most routes cannot be // intercepted, so this is the common case. const nonInterceptedEntry = readExactRouteCacheEntry(now, key.href, null); if (nonInterceptedEntry !== null && !nonInterceptedEntry.couldBeIntercepted) { // Found a match, and the route cannot be intercepted. We can reuse it. return nonInterceptedEntry; } // There was no match. Check again but include the Next-Url this time. return readExactRouteCacheEntry(now, key.href, key.nextUrl); } function getSegmentKeypathForTask(task, route, path) { // When a prefetch includes dynamic data, the search params are included // in the result, so we must include the search string in the segment // cache key. (Note that this is true even if the search string is empty.) // // If we're fetching using PPR, we do not need to include the search params in // the cache key, because the search params are treated as dynamic data. The // cache entry is valid for all possible search param values. const isDynamicTask = task.includeDynamicData || !route.isPPREnabled; return isDynamicTask && path.endsWith('/' + _segment.PAGE_SEGMENT_KEY) ? [ path, task.key.search ] : [ path ]; } function readSegmentCacheEntry(now, routeCacheKey, path) { if (!path.endsWith('/' + _segment.PAGE_SEGMENT_KEY)) { // Fast path. Search params only exist on page segments. return readExactSegmentCacheEntry(now, [ path ]); } // Page segments may or may not contain search params. If they were prefetched // using a dynamic request, then we will have an entry with search params. // Check for that case first. const entryWithSearchParams = readExactSegmentCacheEntry(now, [ path, routeCacheKey.search ]); if (entryWithSearchParams !== null) { return entryWithSearchParams; } // If we did not find an entry with the given search params, check for a // "fallback" entry, where the search params are treated as dynamic data. This // is the common case because PPR/static prerenders always treat search params // as dynamic. // // See corresponding logic in `getSegmentKeypathForTask`. const entryWithoutSearchParams = readExactSegmentCacheEntry(now, [ path ]); return entryWithoutSearchParams; } function readExactSegmentCacheEntry(now, keypath) { const existingEntry = segmentCacheMap.get(keypath); if (existingEntry !== null) { // Check if the entry is stale if (existingEntry.staleAt > now) { // Reuse the existing entry. // Since this is an access, move the entry to the front of the LRU. segmentCacheLru.put(existingEntry); return existingEntry; } else { // This is a stale entry. const revalidatingEntry = existingEntry.revalidating; if (revalidatingEntry !== null) { // There's a revalidation in progress. Upsert it. const upsertedEntry = upsertSegmentEntry(now, keypath, revalidatingEntry); if (upsertedEntry !== null && upsertedEntry.staleAt > now) { // We can use the upserted revalidation entry. return upsertedEntry; } } else { // Evict the stale entry from the cache. deleteSegmentFromCache(existingEntry, keypath); } } } return null; } function readRevalidatingSegmentCacheEntry(now, owner) { const existingRevalidation = owner.revalidating; if (existingRevalidation !== null) { if (existingRevalidation.staleAt > now) { // There's already a revalidation in progress. Or a previous revalidation // failed and it has not yet expired. return existingRevalidation; } else { // Clear the stale revalidation from its owner. clearRevalidatingSegmentFromOwner(owner); } } return null; } function waitForSegmentCacheEntry(pendingEntry) { // Because the entry is pending, there's already a in-progress request. // Attach a promise to the entry that will resolve when the server responds. let promiseWithResolvers = pendingEntry.promise; if (promiseWithResolvers === null) { promiseWithResolvers = pendingEntry.promise = createPromiseWithResolvers(); } else { // There's already a promise we can use } return promiseWithResolvers.promise; } function readOrCreateRouteCacheEntry(now, task) { const key = task.key; const existingEntry = readRouteCacheEntry(now, key); if (existingEntry !== null) { return existingEntry; } // Create a pending entry and add it to the cache. const pendingEntry = { canonicalUrl: null, status: 0, blockedTasks: null, tree: null, head: null, isHeadPartial: true, // Since this is an empty entry, there's no reason to ever evict it. It will // be updated when the data is populated. staleAt: Infinity, // This is initialized to true because we don't know yet whether the route // could be intercepted. It's only set to false once we receive a response // from the server. couldBeIntercepted: true, // Similarly, we don't yet know if the route supports PPR. isPPREnabled: false, // LRU-related fields keypath: null, next: null, prev: null, size: 0 }; const keypath = key.nextUrl === null ? [ key.href ] : [ key.href, key.nextUrl ]; routeCacheMap.set(keypath, pendingEntry); // Stash the keypath on the entry so we know how to remove it from the map // if it gets evicted from the LRU. pendingEntry.keypath = keypath; routeCacheLru.put(pendingEntry); return pendingEntry; } function readOrCreateSegmentCacheEntry(now, task, route, path) { const keypath = getSegmentKeypathForTask(task, route, path); const existingEntry = readExactSegmentCacheEntry(now, keypath); if (existingEntry !== null) { return existingEntry; } // Create a pending entry and add it to the cache. const pendingEntry = createDetachedSegmentCacheEntry(route.staleAt); segmentCacheMap.set(keypath, pendingEntry); // Stash the keypath on the entry so we know how to remove it from the map // if it gets evicted from the LRU. pendingEntry.keypath = keypath; segmentCacheLru.put(pendingEntry); return pendingEntry; } function readOrCreateRevalidatingSegmentEntry(now, prevEntry) { const existingRevalidation = readRevalidatingSegmentCacheEntry(now, prevEntry); if (existingRevalidation !== null) { return existingRevalidation; } const pendingEntry = createDetachedSegmentCacheEntry(prevEntry.staleAt); // Background revalidations are not stored directly in the cache map or LRU; // they're stashed on the entry that they will (potentially) replace. // // Note that we don't actually ever clear this field, except when the entry // expires. When the revalidation finishes, one of two things will happen: // // 1) the revalidation is successful, `prevEntry` is removed from the cache // and garbage collected (so there's no point clearing any of its fields) // 2) the revalidation fails, and we'll use the `revalidating` field to // prevent subsequent revalidation attempts, until it expires. prevEntry.revalidating = pendingEntry; return pendingEntry; } function upsertSegmentEntry(now, keypath, candidateEntry) { // We have a new entry that has not yet been inserted into the cache. Before // we do so, we need to confirm whether it takes precedence over the existing // entry (if one exists). // TODO: We should not upsert an entry if its key was invalidated in the time // since the request was made. We can do that by passing the "owner" entry to // this function and confirming it's the same as `existingEntry`. const existingEntry = readExactSegmentCacheEntry(now, keypath); if (existingEntry !== null) { if (candidateEntry.isPartial && !existingEntry.isPartial) { // Don't replace a full segment with a partial one. A case where this // might happen is if the existing segment was fetched via // <Link prefetch={true}>. // We're going to leave the entry on the owner's `revalidating` field // so that it doesn't get revalidated again unnecessarily. Downgrade the // Fulfilled entry to Rejected and null out the data so it can be garbage // collected. We leave `staleAt` intact to prevent subsequent revalidation // attempts only until the entry expires. const rejectedEntry = candidateEntry; rejectedEntry.status = 3; rejectedEntry.loading = null; rejectedEntry.rsc = null; return null; } // Evict the existing entry from the cache. deleteSegmentFromCache(existingEntry, keypath); } segmentCacheMap.set(keypath, candidateEntry); // Stash the keypath on the entry so we know how to remove it from the map // if it gets evicted from the LRU. candidateEntry.keypath = keypath; segmentCacheLru.put(candidateEntry); return candidateEntry; } function createDetachedSegmentCacheEntry(staleAt) { const emptyEntry = { status: 0, // Default to assuming the fetch strategy will be PPR. This will be updated // when a fetch is actually initiated. fetchStrategy: 0, revalidating: null, rsc: null, loading: null, staleAt, isPartial: true, promise: null, // LRU-related fields keypath: null, next: null, prev: null, size: 0 }; return emptyEntry; } function upgradeToPendingSegment(emptyEntry, fetchStrategy) { const pendingEntry = emptyEntry; pendingEntry.status = 1; pendingEntry.fetchStrategy = fetchStrategy; return pendingEntry; } function deleteRouteFromCache(entry, keypath) { pingBlockedTasks(entry); routeCacheMap.delete(keypath); routeCacheLru.delete(entry); } function deleteSegmentFromCache(entry, keypath) { cancelEntryListeners(entry); segmentCacheMap.delete(keypath); segmentCacheLru.delete(entry); clearRevalidatingSegmentFromOwner(entry); } function clearRevalidatingSegmentFromOwner(owner) { // Revalidating segments are not stored in the cache directly; they're // stored as a field on the entry that they will (potentially) replace. So // to dispose of an existing revalidation, we just need to null out the field // on the owner. const revalidatingSegment = owner.revalidating; if (revalidatingSegment !== null) { cancelEntryListeners(revalidatingSegment); owner.revalidating = null; } } function resetRevalidatingSegmentEntry(owner) { clearRevalidatingSegmentFromOwner(owner); const emptyEntry = createDetachedSegmentCacheEntry(owner.staleAt); owner.revalidating = emptyEntry; return emptyEntry; } function onRouteLRUEviction(entry) { // The LRU evicted this entry. Remove it from the map. const keypath = entry.keypath; if (keypath !== null) { entry.keypath = null; pingBlockedTasks(entry); routeCacheMap.delete(keypath); } } function onSegmentLRUEviction(entry) { // The LRU evicted this entry. Remove it from the map. const keypath = entry.keypath; if (keypath !== null) { entry.keypath = null; cancelEntryListeners(entry); segmentCacheMap.delete(keypath); } } function cancelEntryListeners(entry) { if (entry.status === 1 && entry.promise !== null) { // There were listeners for this entry. Resolve them with `null` to indicate // that the prefetch failed. It's up to the listener to decide how to handle // this case. // NOTE: We don't currently propagate the reason the prefetch was canceled // but we could by accepting a `reason` argument. entry.promise.resolve(null); entry.promise = null; } } function pingBlockedTasks(entry) { const blockedTasks = entry.blockedTasks; if (blockedTasks !== null) { for (const task of blockedTasks){ (0, _scheduler.pingPrefetchTask)(task); } entry.blockedTasks = null; } } function fulfillRouteCacheEntry(entry, tree, head, isHeadPartial, staleAt, couldBeIntercepted, canonicalUrl, isPPREnabled) { const fulfilledEntry = entry; fulfilledEntry.status = 2; fulfilledEntry.tree = tree; fulfilledEntry.head = head; fulfilledEntry.isHeadPartial = isHeadPartial; fulfilledEntry.staleAt = staleAt; fulfilledEntry.couldBeIntercepted = couldBeIntercepted; fulfilledEntry.canonicalUrl = canonicalUrl; fulfilledEntry.isPPREnabled = isPPREnabled; pingBlockedTasks(entry); return fulfilledEntry; } function fulfillSegmentCacheEntry(segmentCacheEntry, rsc, loading, staleAt, isPartial) { const fulfilledEntry = segmentCacheEntry; fulfilledEntry.status = 2; fulfilledEntry.rsc = rsc; fulfilledEntry.loading = loading; fulfilledEntry.staleAt = staleAt; fulfilledEntry.isPartial = isPartial; // Resolve any listeners that were waiting for this data. if (segmentCacheEntry.promise !== null) { segmentCacheEntry.promise.resolve(fulfilledEntry); // Free the promise for garbage collection. fulfilledEntry.promise = null; } return fulfilledEntry; } function rejectRouteCacheEntry(entry, staleAt) { const rejectedEntry = entry; rejectedEntry.status = 3; rejectedEntry.staleAt = staleAt; pingBlockedTasks(entry); } function rejectSegmentCacheEntry(entry, staleAt) { const rejectedEntry = entry; rejectedEntry.status = 3; rejectedEntry.staleAt = staleAt; if (entry.promise !== null) { // NOTE: We don't currently propagate the reason the prefetch was canceled // but we could by accepting a `reason` argument. entry.promise.resolve(null); entry.promise = null; } } function convertRootTreePrefetchToRouteTree(rootTree) { return convertTreePrefetchToRouteTree(rootTree.tree, _segmentvalueencoding.ROOT_SEGMENT_KEY); } function convertTreePrefetchToRouteTree(prefetch, key) { // Converts the route tree sent by the server into the format used by the // cache. The cached version of the tree includes additional fields, such as a // cache key for each segment. Since this is frequently accessed, we compute // it once instead of on every access. This same cache key is also used to // request the segment from the server. let slots = null; const prefetchSlots = prefetch.slots; if (prefetchSlots !== null) { slots = {}; for(let parallelRouteKey in prefetchSlots){ const childPrefetch = prefetchSlots[parallelRouteKey]; const childSegment = childPrefetch.segment; // TODO: Eventually, the param values will not be included in the response // from the server. We'll instead fill them in on the client by parsing // the URL. This is where we'll do that. const childKey = (0, _segmentvalueencoding.encodeChildSegmentKey)(key, parallelRouteKey, (0, _segmentvalueencoding.encodeSegment)(childSegment)); slots[parallelRouteKey] = convertTreePrefetchToRouteTree(childPrefetch, childKey); } } return { key, segment: prefetch.segment, slots, isRootLayout: prefetch.isRootLayout }; } function convertRootFlightRouterStateToRouteTree(flightRouterState) { return convertFlightRouterStateToRouteTree(flightRouterState, _segmentvalueencoding.ROOT_SEGMENT_KEY); } function convertFlightRouterStateToRouteTree(flightRouterState, key) { let slots = null; const parallelRoutes = flightRouterState[1]; for(let parallelRouteKey in parallelRoutes){ const childRouterState = parallelRoutes[parallelRouteKey]; const childSegment = childRouterState[0]; // TODO: Eventually, the param values will not be included in the response // from the server. We'll instead fill them in on the client by parsing // the URL. This is where we'll do that. const childKey = (0, _segmentvalueencoding.encodeChildSegmentKey)(key, parallelRouteKey, (0, _segmentvalueencoding.encodeSegment)(childSegment)); const childTree = convertFlightRouterStateToRouteTree(childRouterState, childKey); if (slots === null) { slots = { [parallelRouteKey]: childTree }; } else { slots[parallelRouteKey] = childTree; } } // The navigation implementation expects the search params to be included // in the segment. However, in the case of a static response, the search // params are omitted. So the client needs to add them back in when reading // from the Segment Cache. // // For consistency, we'll do this for dynamic responses, too. // // TODO: We should move search params out of FlightRouterState and handle them // entirely on the client, similar to our plan for dynamic params. const originalSegment = flightRouterState[0]; const segmentWithoutSearchParams = typeof originalSegment === 'string' && originalSegment.startsWith(_segment.PAGE_SEGMENT_KEY) ? _segment.PAGE_SEGMENT_KEY : originalSegment; return { key, segment: segmentWithoutSearchParams, slots, isRootLayout: flightRouterState[4] === true }; } function convertRouteTreeToFlightRouterState(routeTree) { const parallelRoutes = {}; if (routeTree.slots !== null) { for(const parallelRouteKey in routeTree.slots){ parallelRoutes[parallelRouteKey] = convertRouteTreeToFlightRouterState(routeTree.slots[parallelRouteKey]); } } const flightRouterState = [ routeTree.segment, parallelRoutes, null, null, routeTree.isRootLayout ]; return flightRouterState; } async function fetchRouteOnCacheMiss(entry, task) { // This function is allowed to use async/await because it contains the actual // fetch that gets issued on a cache miss. Notice it writes the result to the // cache entry directly, rather than return data that is then written by // the caller. const key = task.key; const href = key.href; const nextUrl = key.nextUrl; const segmentPath = '/_tree'; const headers = { [_approuterheaders.RSC_HEADER]: '1', [_approuterheaders.NEXT_ROUTER_PREFETCH_HEADER]: '1', [_approuterheaders.NEXT_ROUTER_SEGMENT_PREFETCH_HEADER]: segmentPath }; if (nextUrl !== null) { headers[_approuterheaders.NEXT_URL] = nextUrl; } // In output: "export" mode, we need to add the segment path to the URL. const url = new URL(href); const requestUrl = isOutputExportMode ? addSegmentPathToUrlInOutputExportMode(url, segmentPath) : url; try { const response = await fetchPrefetchResponse(requestUrl, headers); if (!response || !response.ok || // 204 is a Cache miss. Though theoretically this shouldn't happen when // PPR is enabled, because we always respond to route tree requests, even // if it needs to be blockingly generated on demand. response.status === 204 || !response.body) { // Server responded with an error, or with a miss. We should still cache // the response, but we can try again after 10 seconds. rejectRouteCacheEntry(entry, Date.now() + 10 * 1000); return null; } // TODO: The canonical URL is the href without the origin. I think // historically the reason for this is because the initial canonical URL // gets passed as a prop to the top-level React component, which means it // needs to be computed during SSR. If it were to include the origin, it // would need to always be same as location.origin on the client, to prevent // a hydration mismatch. To sidestep this complexity, we omit the origin. // // However, since this is neither a native URL object nor a fully qualified // URL string, we need to be careful about how we use it. To prevent subtle // mistakes, we should create a special type for it, instead of just string. // Or, we should just use a (readonly) URL object instead. The type of the // prop that we pass to seed the initial state does not need to be the same // type as the state itself. const canonicalUrl = (0, _createhreffromurl.createHrefFromUrl)(new URL(response.redirected ? removeSegmentPathFromURLInOutputExportMode(href, requestUrl.href, response.url) : href)); // Check whether the response varies based on the Next-Url header. const varyHeader = response.headers.get('vary'); const couldBeIntercepted = varyHeader !== null && varyHeader.includes(_approuterheaders.NEXT_URL); // Track when the network connection closes. const closed = createPromiseWithResolvers(); // This checks whether the response was served from the per-segment cache, // rather than the old prefetching flow. If it fails, it implies that PPR // is disabled on this route. const routeIsPPREnabled = response.headers.get(_approuterheaders.NEXT_DID_POSTPONE_HEADER) === '2' || // In output: "export" mode, we can't rely on response headers. But if we // receive a well-formed response, we can assume it's a static response, // because all data is static in this mode. isOutputExportMode; if (routeIsPPREnabled) { const prefetchStream = createPrefetchResponseStream(response.body, closed.resolve, function onResponseSizeUpdate(size) { routeCacheLru.updateSize(entry, size); }); const serverData = await (0, _fetchserverresponse.createFromNextReadableStream)(prefetchStream); if (serverData.buildId !== (0, _appbuildid.getAppBuildId)()) { // The server build does not match the client. Treat as a 404. During // an actual navigation, the router will trigger an MPA navigation. // TODO: Consider moving the build ID to a response header so we can check // it before decoding the response, and so there's one way of checking // across all response types. rejectRouteCacheEntry(entry, Date.now() + 10 * 1000); return null; } const staleTimeMs = serverData.staleTime * 1000; fulfillRouteCacheEntry(entry, convertRootTreePrefetchToRouteTree(serverData), serverData.head, serverData.isHeadPartial, Date.now() + staleTimeMs, couldBeIntercepted, canonicalUrl, routeIsPPREnabled); } else { // PPR is not enabled for this route. The server responds with a // different format (FlightRouterState) that we need to convert. // TODO: We will unify the responses eventually. I'm keeping the types // separate for now because FlightRouterState has so many // overloaded concerns. const prefetchStream = createPrefetchResponseStream(response.body, closed.resolve, function onResponseSizeUpdate(size) { routeCacheLru.updateSize(entry, size); }); const serverData = await (0, _fetchserverresponse.createFromNextReadableStream)(prefetchStream); writeDynamicTreeResponseIntoCache(Date.now(), task, response, serverData, entry, couldBeIntercepted, canonicalUrl, routeIsPPREnabled); } if (!couldBeIntercepted && nextUrl !== null) { // This route will never be intercepted. So we can use this entry for all // requests to this route, regardless of the Next-Url header. This works // because when reading the cache we always check for a valid // non-intercepted entry first. // // Re-key the entry. Since we're in an async task, we must first confirm // that the entry hasn't been concurrently modified by a different task. const currentKeypath = [ href, nextUrl ]; const expectedEntry = routeCacheMap.get(currentKeypath); if (expectedEntry === entry) { routeCacheMap.delete(currentKeypath); const newKeypath = [ href ]; routeCacheMap.set(newKeypath, entry); // We don't need to update the LRU because the entry is already in it. // But since we changed the keypath, we do need to update that, so we // know how to remove it from the map if it gets evicted from the LRU. entry.keypath = newKeypath; } else { // Something else modified this entry already. Since the re-keying is // just a performance optimization, we can safely skip it. } } // Return a promise that resolves when the network connection closes, so // the scheduler can track the number of concurrent network connections. return { value: null, closed: closed.promise }; } catch (error) { // Either the connection itself failed, or something bad happened while // decoding the response. rejectRouteCacheEntry(entry, Date.now() + 10 * 1000); return null; } } async function fetchSegmentOnCacheMiss(route, segmentCacheEntry, routeKey, segmentPath) { // This function is allowed to use async/await because it contains the actual // fetch that gets issued on a cache miss. Notice it writes the result to the // cache entry directly, rather than return data that is then written by // the caller. // // Segment fetches are non-blocking so we don't need to ping the scheduler // on completion. // Use the canonical URL to request the segment, not the original URL. These // are usually the same, but the canonical URL will be different if the route // tree response was redirected. To avoid an extra waterfall on every segment // request, we pass the redirected URL instead of the original one. const url = new URL(route.canonicalUrl, routeKey.href); const nextUrl = routeKey.nextUrl; const normalizedSegmentPath = segmentPath === _segmentvalueencoding.ROOT_SEGMENT_KEY ? // handling of these requests, we encode the root segment path as // `_index` instead of as an empty string. This should be treated as // an implementation detail and not as a stable part of the protocol. // It just needs to match the equivalent logic that happens when // prerendering the responses. It should not leak outside of Next.js. '/_index' : segmentPath; const headers = { [_approuterheaders.RSC_HEADER]: '1', [_approuterheaders.NEXT_ROUTER_PREFETCH_HEADER]: '1', [_approuterheaders.NEXT_ROUTER_SEGMENT_PREFETCH_HEADER]: normalizedSegmentPath }; if (nextUrl !== null) { headers[_approuterheaders.NEXT_URL] = nextUrl; } const requestUrl = isOutputExportMode ? addSegmentPathToUrlInOutputExportMode(url, normalizedSegmentPath) : url; try { const response = await fetchPrefetchResponse(requestUrl, headers); if (!response || !response.ok || response.status === 204 || // Cache miss // This checks whether the response was served from the per-segment cache, // rather than the old prefetching flow. If it fails, it implies that PPR // is disabled on this route. Theoretically this should never happen // because we only issue requests for segments once we've verified that // the route supports PPR. response.headers.get(_approuterheaders.NEXT_DID_POSTPONE_HEADER) !== '2' && // In output: "export" mode, we can't rely on response headers. But if // we receive a well-formed response, we can assume it's a static // response, because all data is static in this mode. !isOutputExportMode || !response.body) { // Server responded with an error, or with a miss. We should still cache // the response, but we can try again after 10 seconds. rejectSegmentCacheEntry(segmentCacheEntry, Date.now() + 10 * 1000); return null; } // Track when the network connection closes. const closed = createPromiseWithResolvers(); // Wrap the original stream in a new stream that never closes. That way the // Flight client doesn't error if there's a hanging promise. const prefetchStream = createPrefetchResponseStream(response.body, closed.resolve, function onResponseSizeUpdate(size) { segmentCacheLru.updateSize(segmentCacheEntry, size); }); const serverData = await (0, _fetchserverresponse.createFromNextReadableStream)(prefetchStream); if (serverData.buildId !== (0, _appbuildid.getAppBuildId)()) { // The server build does not match the client. Treat as a 404. During // an actual navigation, the router will trigger an MPA navigation. // TODO: Consider moving the build ID to a response header so we can check // it before decoding the response, and so there's one way of checking // across all response types. rejectSegmentCacheEntry(segmentCacheEntry, Date.now() + 10 * 1000); return null; } return { value: fulfillSegmentCacheEntry(segmentCacheEntry, serverData.rsc, serverData.loading, // TODO: The server does not currently provide per-segment stale time. // So we use the stale time of the route. route.staleAt, serverData.isPartial), // Return a promise that resolves when the network connection closes, so // the scheduler can track the number of concurrent network connections. closed: closed.promise }; } catch (error) { // Either the connection itself failed, or something bad happened while // decoding the response. rejectSegmentCacheEntry(segmentCacheEntry, Date.now() + 10 * 1000); return null; } } async function fetchSegmentPrefetchesUsingDynamicRequest(task, route, fetchStrategy, dynamicRequestTree, spawnedEntries) { const url = new URL(route.canonicalUrl, task.key.href); const nextUrl = task.key.nextUrl; const headers = { [_approuterheaders.RSC_HEADER]: '1', [_approuterheaders.NEXT_ROUTER_STATE_TREE_HEADER]: encodeURIComponent(JSON.stringify(dynamicRequestTree)) }; if (nextUrl !== null) { headers[_approuterheaders.NEXT_URL] = nextUrl; } // Only set the prefetch header if we're not doing a "full" prefetch. We // omit the prefetch header from a full prefetch because it's essentially // just a navigation request that happens ahead of time — it should include // all the same data in the response. if (fetchStrategy !== 1) { headers[_approuterheaders.NEXT_ROUTER_PREFETCH_HEADER] = '1'; } try { const response = await fetchPrefetchResponse(url, headers); if (!response || !response.ok || !response.body) { // Server responded with an error, or with a miss. We should still cache // the response, but we can try again after 10 seconds. rejectSegmentEntriesIfStillPending(spawnedEntries, Date.now() + 10 * 1000); return null; } // Track when the network connection closes. const closed = createPromiseWithResolvers(); let fulfilledEntries = null; const prefetchStream = createPrefetchResponseStream(response.body, closed.resolve, function onResponseSizeUpdate(totalBytesReceivedSoFar) { // When processing a dynamic response, we don't know how large each // individual segment is, so approximate by assiging each segment // the average of the total response size. if (fulfilledEntries === null) { // Haven't received enough data yet to know which segments // were included. return; } const averageSize = totalBytesReceivedSoFar / fulfilledEntries.length; for (const entry of fulfilledEntries){ segmentCacheLru.updateSize(entry, averageSize); } }); const serverData = await (0, _fetchserverresponse.createFromNextReadableStream)(prefetchStream); // Since we did not set the prefetch header, the response from the server // will never contain dynamic holes. const isResponsePartial = false; // Aside from writing the data into the cache, this function also returns // the entries that were fulfilled, so we can streamingly update their sizes // in the LRU as more data comes in. fulfilledEntries = writeDynamicRenderResponseIntoCache(Date.now(), task, response, serverData, isResponsePartial, route, spawnedEntries); // Return a promise that resolves when the network connection closes, so // the scheduler can track the number of concurrent network connections. return { value: null, closed: closed.promise }; } catch (error) { rejectSegmentEntriesIfStillPending(spawnedEntries, Date.now() + 10 * 1000); return null; } } function writeDynamicTreeResponseIntoCache(now, task, response, serverData, entry, couldBeIntercepted, canonicalUrl, routeIsPPREnabled) { if (serverData.b !== (0, _appbuildid.getAppBuildId)()) { // The server build does not match the client. Treat as a 404. During // an actual navigation, the router will trigger an MPA navigation. // TODO: Consider moving the build ID to a response header so we can check // it before decoding the response, and so there's one way of checking // across all response types. rejectRouteCacheEntry(entry, now + 10 * 1000); return; } const normalizedFlightDataResult = (0, _flightdatahelpers.normalizeFlightData)(serverData.f); if (// A string result means navigating to this route will result in an // MPA navigation. typeof normalizedFlightDataResult === 'string' || normalizedFlightDataResult.length !== 1) { rejectRouteCacheEntry(entry, now + 10 * 1000); return; } const flightData = normalizedFlightDataResult[0]; if (!flightData.isRootRender) { // Unexpected response format. rejectRouteCacheEntry(entry, now + 10 * 1000); return; } const flightRouterState = flightData.tree; // TODO: Extract to function const staleTimeHeaderSeconds = response.headers.get(_approuterheaders.NEXT_ROUTER_STALE_TIME_HEADER); const staleTimeMs = staleTimeHeaderSeconds !== null ? parseInt(staleTimeHeaderSeconds, 10) * 1000 : _prefetchcacheutils.STATIC_STALETIME_MS; // If the response contains dynamic holes, then we must conservatively assume // that any individual segment might contain dynamic holes, and also the // head. If it did not contain dynamic holes, then we can assume every segment // and the head is completely static. const isResponsePartial = response.headers.get(_approuterheaders.NEXT_DID_POSTPONE_HEADER) === '1'; const fulfilledEntry = fulfillRouteCacheEntry(entry, convertRootFlightRouterStateToRouteTree(flightRouterState), flightData.head, isResponsePartial, now + staleTimeMs, couldBeIntercepted, canonicalUrl, routeIsPPREnabled); // If the server sent segment data as part of the response, we should write // it into the cache to prevent a second, redundant prefetch request. // // TODO: When `clientSegmentCache` is enabled, the server does not include // segment data when responding to a route tree prefetch request. However, // when `clientSegmentCache` is set to "client-only", and PPR is enabled (or // the page is fully static), the normal check is bypassed and the server // responds with the full page. This is a temporary situation until we can // remove the "client-only" option. Then, we can delete this function call. writeDynamicRenderResponseIntoCache(now, task, response, serverData, isResponsePartial, fulfilledEntry, null); } function rejectSegmentEntriesIfStillPending(entries, staleAt) { const fulfilledEntries = []; for (const entry of entries.values()){ if (entry.status === 1) { rejectSegmentCacheEntry(entry, staleAt); } else if (entry.status === 2) { fulfilledEntries.push(entry); } } return fulfilledEntries; } function writeDynamicRenderResponseIntoCache(now, task, response, serverData, isResponsePartial, route, spawnedEntries) { if (serverData.b !== (0, _appbuildid.getAppBuildId)()) { // The server build does not match the client. Treat as a 404. During // an actual navigation, the router will trigger an MPA navigation. // TODO: Consider moving the build ID to a response header so we can check // it before decoding the response, and so there's one way of checking // across all response types. if (spawnedEntries !== null) { rejectSegmentEntriesIfStillPending(spawnedEntries, now + 10 * 1000); } return null; } const flightDatas = (0, _flightdatahelpers.normalizeFlightData)(serverData.f); if (typeof flightDatas === 'string') { // This means navigating to this route will result in an MPA navigation. // TODO: We should cache this, too, so that the MPA navigation is immediate. return null; } for (const flightData of flightDatas){ const seedData = flightData.seedData; if (seedData !== null) { // The data sent by the server represents only a subtree of the app. We // need to find the part of the task tree that matches the response. // // segmentPath represents the parent path of subtree. It's a repeating // pattern of parallel route key and segment: // // [string, Segment, string, Segment, string, Segment, ...] const segmentPath = flightData.segmentPath; let segmentKey = _segmentvalueencoding.ROOT_SEGMENT_KEY; for(let i = 0; i < segmentPath.length; i += 2){ const parallelRouteKey = segmentPath[i]; const segment = segmentPath[i + 1]; segmentKey = (0, _segmentvalueencoding.encodeChildSegmentKey)(segmentKey, parallelRouteKey, (0, _segmentvalueencoding.encodeSegment)(segment)); } const staleTimeHeaderSeconds = response.headers.get(_approuterheaders.NEXT_ROUTER_STALE_TIME_HEADER); const staleTimeMs = staleTimeHeaderSeconds !== null ? parseInt(staleTimeHeaderSeconds, 10) * 1000 : _prefetchcacheutils.STATIC_STALETIME_MS; writeSeedDataIntoCache(now, task, route, now + staleTimeMs, seedData, isResponsePartial, segmentKey, spawnedEntries); } } // Any entry that's still pending was intentionally not rendered by the // server, because it was inside the loading boundary. Mark them as rejected // so we know not to fetch them again. // TODO: If PPR is enabled on some routes but not others, then it's possible // that a different page is able to do a per-segment prefetch of one of the // segments we're marking as rejected here. We should mark on the segment // somehow that the reason for the rejection is because of a non-PPR prefetch. // That way a per-segment prefetch knows to disregard the rejection. if (spawnedEntries !== null) { const fulfilledEntries = rejectSegmentEntriesIfStillPending(spawnedEntries, now + 10 * 1000); return fulfilledEntries; } return null; } function writeSeedDataIntoCache(now, task, route, staleAt, seedData, isResponsePartial, key, entriesOwnedByCurrentTask) { // This function is used to write the result of a dynamic server request // (CacheNodeSeedData) into the prefetch cache. It's used in cases where we // want to treat a dynamic response as if it were static. The two examples // where this happens are <Link prefetch={true}> (which implicitly opts // dynamic data into being static) and when prefetching a PPR-disabled route const rsc = seedData[1]; const loading = seedData[3]; const isPartial = rsc === null || isResponsePartial; // We should only write into cache entries that are owned by us. Or create // a new one and write into that. We must never write over an entry that was // created by a different task, because that causes data races. const ownedEntry = entriesOwnedByCurrentTask !== null ? entriesOwnedByCurrentTask.get(key) : undefined; if (ownedEntry !== undefined) { fulfillSegmentCacheEntry(ownedEntry, rsc, loading, staleAt, isPartial); } else { // There's no matching entry. Attempt to create a new one. const possiblyNewEntry = readOrCreateSegmentCacheEntry(now, task, route, key); if (possiblyNewEntry.status === 0) { // Confirmed this is a new entry. We can fulfill it. const newEntry = possiblyNewEntry; fulfillSegmentCacheEntry(newEntry, rsc, loading, staleAt, isPartial); } else { // There was already an entry in the cache. But we may be able to // replace it with the new one from the server. const newEntry = fulfillSegmentCacheEntry(createDetachedSegmentCacheEntry(staleAt), rsc, loading, staleAt, isPartial); upsertSegmentEntry(now, getSegmentKeypathForTask(task, route, key), newEntry); } } // Recursively write the child data into the cache. const seedDataChildren = seedData[2]; if (seedDataChildren !== null) { for(const parallelRouteKey in seedDataChildren){ const childSeedData = seedDataChildren[parallelRouteKey]; if (childSeedData !== null) { const childSegment = childSeedData[0]; writeSeedDataIntoCache(now, task, route, staleAt, childSeedData, isResponsePartial, (0, _segmentvalueencoding.encodeChildSegmentKey)(key, parallelRouteKey, (0, _segmentvalueencoding.encodeSegment)(childSegment)), entriesOwnedByCurrentTask); } } } } async function