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"use strict"; Object.defineProperty(exports, "__esModule", { value: true }); 0 && (module.exports = { EntryStatus: null, canNewFetchStrategyProvideMoreContent: null, convertRouteTreeToFlightRouterState: null, createDetachedSegmentCacheEntry: null, fetchRouteOnCacheMiss: null, fetchSegmentOnCacheMiss: null, fetchSegmentPrefetchesUsingDynamicRequest: null, getCanonicalSegmentKeypath: null, getCurrentCacheVersion: null, getGenericSegmentKeypathFromFetchStrategy: null, overwriteRevalidatingSegmentCacheEntry: null, pingInvalidationListeners: null, readOrCreateRevalidatingSegmentEntry: null, readOrCreateRouteCacheEntry: null, readOrCreateSegmentCacheEntry: null, readRouteCacheEntry: null, readSegmentCacheEntry: null, requestOptimisticRouteCacheEntry: 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; }, canNewFetchStrategyProvideMoreContent: function() { return canNewFetchStrategyProvideMoreContent; }, convertRouteTreeToFlightRouterState: function() { return convertRouteTreeToFlightRouterState; }, createDetachedSegmentCacheEntry: function() { return createDetachedSegmentCacheEntry; }, fetchRouteOnCacheMiss: function() { return fetchRouteOnCacheMiss; }, fetchSegmentOnCacheMiss: function() { return fetchSegmentOnCacheMiss; }, fetchSegmentPrefetchesUsingDynamicRequest: function() { return fetchSegmentPrefetchesUsingDynamicRequest; }, getCanonicalSegmentKeypath: function() { return getCanonicalSegmentKeypath; }, getCurrentCacheVersion: function() { return getCurrentCacheVersion; }, getGenericSegmentKeypathFromFetchStrategy: function() { return getGenericSegmentKeypathFromFetchStrategy; }, overwriteRevalidatingSegmentCacheEntry: function() { return overwriteRevalidatingSegmentCacheEntry; }, pingInvalidationListeners: function() { return pingInvalidationListeners; }, readOrCreateRevalidatingSegmentEntry: function() { return readOrCreateRevalidatingSegmentEntry; }, readOrCreateRouteCacheEntry: function() { return readOrCreateRouteCacheEntry; }, readOrCreateSegmentCacheEntry: function() { return readOrCreateSegmentCacheEntry; }, readRouteCacheEntry: function() { return readRouteCacheEntry; }, readSegmentCacheEntry: function() { return readSegmentCacheEntry; }, requestOptimisticRouteCacheEntry: function() { return requestOptimisticRouteCacheEntry; }, revalidateEntireCache: function() { return revalidateEntireCache; }, upgradeToPendingSegment: function() { return upgradeToPendingSegment; }, upsertSegmentEntry: function() { return upsertSegmentEntry; }, waitForSegmentCacheEntry: function() { return waitForSegmentCacheEntry; } }); const _approutertypes = require("../../../shared/lib/app-router-types"); 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 _cachekey = require("./cache-key"); const _routeparams = require("../../route-params"); const _cachemap = require("./cache-map"); const _segmentvalueencoding = require("../../../shared/lib/segment-cache/segment-value-encoding"); const _flightdatahelpers = require("../../flight-data-helpers"); const _navigatereducer = require("../router-reducer/reducers/navigate-reducer"); const _links = require("../links"); const _segment = require("../../../shared/lib/segment"); const _outputexportprefetchencoding = require("../../../shared/lib/segment-cache/output-export-prefetch-encoding"); const _segmentcache = require("../segment-cache"); const _promisewithresolvers = require("../../../shared/lib/promise-with-resolvers"); 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; }({}); const isOutputExportMode = process.env.NODE_ENV === 'production' && process.env.__NEXT_CONFIG_OUTPUT === 'export'; /** * Ensures a minimum stale time of 30s to avoid issues where the server sends a too * short-lived stale time, which would prevent anything from being prefetched. */ function getStaleTimeMs(staleTimeSeconds) { return Math.max(staleTimeSeconds, 30) * 1000; } let routeCacheMap = (0, _cachemap.createCacheMap)(); let segmentCacheMap = (0, _cachemap.createCacheMap)(); // All invalidation listeners for the whole cache are tracked in single set. // Since we don't yet support tag or path-based invalidation, there's no point // tracking them any more granularly than this. Once we add granular // invalidation, that may change, though generally the model is to just notify // the listeners and allow the caller to poll the prefetch cache with a new // prefetch task if desired. let invalidationListeners = null; // Incrementing counter used to track cache invalidations. let currentCacheVersion = 0; function getCurrentCacheVersion() { return currentCacheVersion; } function revalidateEntireCache(nextUrl, tree) { // Increment the current cache version. This does not eagerly evict anything // from the cache, but because all the entries are versioned, and we check // the version when reading from the cache, this effectively causes all // entries to be evicted lazily. We do it lazily because in the future, // actions like revalidateTag or refresh will not evict the entire cache, // but rather some subset of the entries. currentCacheVersion++; // Start a cooldown before re-prefetching to allow CDN cache propagation. (0, _scheduler.startRevalidationCooldown)(); // Prefetch all the currently visible links again, to re-fill the cache. (0, _links.pingVisibleLinks)(nextUrl, tree); // Similarly, notify all invalidation listeners (i.e. those passed to // `router.prefetch(onInvalidate)`), so they can trigger a new prefetch // if needed. pingInvalidationListeners(nextUrl, tree); } function attachInvalidationListener(task) { // This function is called whenever a prefetch task reads a cache entry. If // the task has an onInvalidate function associated with it — i.e. the one // optionally passed to router.prefetch(onInvalidate) — then we attach that // listener to the every cache entry that the task reads. Then, if an entry // is invalidated, we call the function. if (task.onInvalidate !== null) { if (invalidationListeners === null) { invalidationListeners = new Set([ task ]); } else { invalidationListeners.add(task); } } } function notifyInvalidationListener(task) { const onInvalidate = task.onInvalidate; if (onInvalidate !== null) { // Clear the callback from the task object to guarantee it's not called more // than once. task.onInvalidate = null; // This is a user-space function, so we must wrap in try/catch. try { onInvalidate(); } catch (error) { if (typeof reportError === 'function') { reportError(error); } else { console.error(error); } } } } function pingInvalidationListeners(nextUrl, tree) { // The rough equivalent of pingVisibleLinks, but for onInvalidate callbacks. // This is called when the Next-Url or the base tree changes, since those // may affect the result of a prefetch task. It's also called after a // cache invalidation. if (invalidationListeners !== null) { const tasks = invalidationListeners; invalidationListeners = null; for (const task of tasks){ if ((0, _scheduler.isPrefetchTaskDirty)(task, nextUrl, tree)) { notifyInvalidationListener(task); } } } } function readRouteCacheEntry(now, key) { const keypath = [ key.pathname, key.search, key.nextUrl ]; const isRevalidation = false; return (0, _cachemap.getFromCacheMap)(now, getCurrentCacheVersion(), routeCacheMap, keypath, isRevalidation); } function getCanonicalSegmentKeypath(route, cacheKey) { // Returns the actual keypath for a segment, without omitting any params. return [ cacheKey, cacheKey.endsWith('/' + _segment.PAGE_SEGMENT_KEY) ? route.renderedSearch : // to include it in the keypath. _cachemap.Fallback ]; } function getGenericSegmentKeypathFromFetchStrategy(fetchStrategy, route, cacheKey) { // Returns the most generic possible keypath for a segment, based on the // strategy used to fetch it, i.e. static/PPR versus runtime prefetching. // // This is used when _writing_ to the cache. We want to choose the most // generic keypath so that it can be reused as much as possible. // // We may be able to re-key the response to something even more generic once // we receive it — for example, if the server tells us that the response // doesn't vary on a particular param — but even before we send the request, // we know somethings based on the fetch strategy alone. const doesVaryOnSearchParams = // Non-page segments never include search params cacheKey.endsWith('/' + _segment.PAGE_SEGMENT_KEY) && // Only a runtime prefetch will include search params in the result. Static // prefetches never include search params, so they can be reused across all // possible search param values. (fetchStrategy === _segmentcache.FetchStrategy.Full || fetchStrategy === _segmentcache.FetchStrategy.PPRRuntime); const keypath = [ cacheKey, doesVaryOnSearchParams ? route.renderedSearch : _cachemap.Fallback ]; return keypath; } function readSegmentCacheEntry(now, keypath) { const isRevalidation = false; return (0, _cachemap.getFromCacheMap)(now, getCurrentCacheVersion(), segmentCacheMap, keypath, isRevalidation); } function readRevalidatingSegmentCacheEntry(now, keypath) { const isRevalidation = true; return (0, _cachemap.getFromCacheMap)(now, getCurrentCacheVersion(), segmentCacheMap, keypath, isRevalidation); } 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 = (0, _promisewithresolvers.createPromiseWithResolvers)(); } else { // There's already a promise we can use } return promiseWithResolvers.promise; } function readOrCreateRouteCacheEntry(now, task, key) { attachInvalidationListener(task); 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, // 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, renderedSearch: null, TODO_metadataStatus: 0, TODO_isHeadDynamic: false, // Map-related fields ref: null, size: 0, // 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, version: getCurrentCacheVersion() }; const keypath = [ key.pathname, key.search, key.nextUrl ]; const isRevalidation = false; (0, _cachemap.setInCacheMap)(routeCacheMap, keypath, pendingEntry, isRevalidation); return pendingEntry; } function requestOptimisticRouteCacheEntry(now, requestedUrl, nextUrl) { // This function is called during a navigation when there was no matching // route tree in the prefetch cache. Before de-opting to a blocking, // unprefetched navigation, we will first attempt to construct an "optimistic" // route tree by checking the cache for similar routes. // // Check if there's a route with the same pathname, but with different // search params. We can then base our optimistic route tree on this entry. // // Conceptually, we are simulating what would happen if we did perform a // prefetch the requested URL, under the assumption that the server will // not redirect or rewrite the request in a different manner than the // base route tree. This assumption might not hold, in which case we'll have // to recover when we perform the dynamic navigation request. However, this // is what would happen if a route were dynamically rewritten/redirected // in between the prefetch and the navigation. So the logic needs to exist // to handle this case regardless. // Look for a route with the same pathname, but with an empty search string. // TODO: There's nothing inherently special about the empty search string; // it's chosen somewhat arbitrarily, with the rationale that it's the most // likely one to exist. But we should update this to match _any_ search // string. The plan is to generalize this logic alongside other improvements // related to "fallback" cache entries. const requestedSearch = requestedUrl.search; if (requestedSearch === '') { // The caller would have already checked if a route with an empty search // string is in the cache. So we can bail out here. return null; } const urlWithoutSearchParams = new URL(requestedUrl); urlWithoutSearchParams.search = ''; const routeWithNoSearchParams = readRouteCacheEntry(now, (0, _cachekey.createCacheKey)(urlWithoutSearchParams.href, nextUrl)); if (routeWithNoSearchParams === null || routeWithNoSearchParams.status !== 2) { // Bail out of constructing an optimistic route tree. This will result in // a blocking, unprefetched navigation. return null; } // Now we have a base route tree we can "patch" with our optimistic values. const TODO_isHeadDynamic = routeWithNoSearchParams.TODO_isHeadDynamic; let head; let isHeadPartial; let TODO_metadataStatus; if (TODO_isHeadDynamic) { // If the head was fetched via dynamic request, then we don't know // whether it accessed search params. So we must be conservative — we // cannot reuse it. The head will stream in during the dynamic navigation. // TODO: When Cache Components is enabled, we should track whether the // head varied on search params. // TODO: Because we're rendering a `null` viewport as the partial state, the // viewport will not block the navigation; it will stream in later, // alongside the metadata. Viewport is supposed to be blocking. This is // a subtle bug in the old implementation that we've preserved here. It's // rare enough that we're not going to fix it for apps that don't enable // Cache Components; when Cache Components is enabled, though, we should // use an infinite promise here to block the navigation. But only if the // entry actually varies on search params. head = [ null, null ]; // Setting this to `true` ensures that on navigation, the head is requested. isHeadPartial = true; TODO_metadataStatus = 0; } else { // The head was fetched via a static/PPR request. So it's guaranteed to // not contain search params. We can reuse it. head = routeWithNoSearchParams.head; isHeadPartial = routeWithNoSearchParams.isHeadPartial; TODO_metadataStatus = 0; } // Optimistically assume that redirects for the requested pathname do // not vary on the search string. Therefore, if the base route was // redirected to a different search string, then the optimistic route // should be redirected to the same search string. Otherwise, we use // the requested search string. const canonicalUrlForRouteWithNoSearchParams = new URL(routeWithNoSearchParams.canonicalUrl, requestedUrl.origin); const optimisticCanonicalSearch = canonicalUrlForRouteWithNoSearchParams.search !== '' ? canonicalUrlForRouteWithNoSearchParams.search : requestedSearch; // Similarly, optimistically assume that rewrites for the requested // pathname do not vary on the search string. Therefore, if the base // route was rewritten to a different search string, then the optimistic // route should be rewritten to the same search string. Otherwise, we use // the requested search string. const optimisticRenderedSearch = routeWithNoSearchParams.renderedSearch !== '' ? routeWithNoSearchParams.renderedSearch : requestedSearch; const optimisticUrl = new URL(routeWithNoSearchParams.canonicalUrl, location.origin); optimisticUrl.search = optimisticCanonicalSearch; const optimisticCanonicalUrl = (0, _createhreffromurl.createHrefFromUrl)(optimisticUrl); // Clone the base route tree, and override the relevant fields with our // optimistic values. const optimisticEntry = { canonicalUrl: optimisticCanonicalUrl, status: 2, // This isn't cloned because it's instance-specific blockedTasks: null, tree: routeWithNoSearchParams.tree, head, isHeadPartial, couldBeIntercepted: routeWithNoSearchParams.couldBeIntercepted, isPPREnabled: routeWithNoSearchParams.isPPREnabled, // Override the rendered search with the optimistic value. renderedSearch: optimisticRenderedSearch, TODO_metadataStatus, TODO_isHeadDynamic, // Map-related fields ref: null, size: 0, staleAt: routeWithNoSearchParams.staleAt, version: routeWithNoSearchParams.version }; // Do not insert this entry into the cache. It only exists so we can // perform the current navigation. Just return it to the caller. return optimisticEntry; } function readOrCreateSegmentCacheEntry(now, fetchStrategy, route, cacheKey) { const canonicalKeypath = getCanonicalSegmentKeypath(route, cacheKey); const existingEntry = readSegmentCacheEntry(now, canonicalKeypath); if (existingEntry !== null) { return existingEntry; } // Create a pending entry and add it to the cache. const genericKeypath = getGenericSegmentKeypathFromFetchStrategy(fetchStrategy, route, cacheKey); const pendingEntry = createDetachedSegmentCacheEntry(route.staleAt); const isRevalidation = false; (0, _cachemap.setInCacheMap)(segmentCacheMap, genericKeypath, pendingEntry, isRevalidation); return pendingEntry; } function readOrCreateRevalidatingSegmentEntry(now, fetchStrategy, route, cacheKey) { // This function is called when we've already confirmed that a particular // segment is cached, but we want to perform another request anyway in case it // returns more complete and/or fresher data than we already have. The logic // for deciding whether to replace the existing entry is handled elsewhere; // this function just handles retrieving a cache entry that we can use to // track the revalidation. // // The reason revalidations are stored in the cache is because we need to be // able to dedupe multiple revalidation requests. The reason they have to be // handled specially is because we shouldn't overwrite a "normal" entry if // one exists at the same keypath. So, for each internal cache location, there // is a special "revalidation" slot that is used solely for this purpose. // // You can think of it as if all the revalidation entries were stored in a // separate cache map from the canonical entries, and then transfered to the // canonical cache map once the request is complete — this isn't how it's // actually implemented, since it's more efficient to store them in the same // data structure as the normal entries, but that's how it's modeled // conceptually. // TODO: Once we implement Fallback behavior for params, where an entry is // re-keyed based on response information, we'll need to account for the // possibility that the keypath of the previous entry is more generic than // the keypath of the revalidating entry. In other words, the server could // return a less generic entry upon revalidation. For now, though, this isn't // a concern because the keypath is based solely on the prefetch strategy, // not on data contained in the response. const canonicalKeypath = getCanonicalSegmentKeypath(route, cacheKey); const existingEntry = readRevalidatingSegmentCacheEntry(now, canonicalKeypath); if (existingEntry !== null) { return existingEntry; } // Create a pending entry and add it to the cache. const genericKeypath = getGenericSegmentKeypathFromFetchStrategy(fetchStrategy, route, cacheKey); const pendingEntry = createDetachedSegmentCacheEntry(route.staleAt); const isRevalidation = true; (0, _cachemap.setInCacheMap)(segmentCacheMap, genericKeypath, pendingEntry, isRevalidation); return pendingEntry; } function overwriteRevalidatingSegmentCacheEntry(fetchStrategy, route, cacheKey) { // This function is called when we've already decided to replace an existing // revalidation entry. Create a new entry and write it into the cache, // overwriting the previous value. const genericKeypath = getGenericSegmentKeypathFromFetchStrategy(fetchStrategy, route, cacheKey); const pendingEntry = createDetachedSegmentCacheEntry(route.staleAt); const isRevalidation = true; (0, _cachemap.setInCacheMap)(segmentCacheMap, genericKeypath, pendingEntry, isRevalidation); 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`. if ((0, _cachemap.isValueExpired)(now, getCurrentCacheVersion(), candidateEntry)) { // The entry is expired. We cannot upsert it. return null; } const existingEntry = readSegmentCacheEntry(now, keypath); if (existingEntry !== null) { // Don't replace a more specific segment with a less-specific one. A case where this // might happen is if the existing segment was fetched via // `<Link prefetch={true}>`. if (// We fetched the new segment using a different, less specific fetch strategy // than the segment we already have in the cache, so it can't have more content. candidateEntry.fetchStrategy !== existingEntry.fetchStrategy && !canNewFetchStrategyProvideMoreContent(existingEntry.fetchStrategy, candidateEntry.fetchStrategy) || // The existing entry isn't partial, but the new one is. // (TODO: can this be true if `candidateEntry.fetchStrategy >= existingEntry.fetchStrategy`?) !existingEntry.isPartial && candidateEntry.isPartial) { // We're going to leave revalidating entry in the cache 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. (0, _cachemap.deleteFromCacheMap)(existingEntry); } const isRevalidation = false; (0, _cachemap.setInCacheMap)(segmentCacheMap, keypath, candidateEntry, isRevalidation); 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: _segmentcache.FetchStrategy.PPR, rsc: null, loading: null, isPartial: true, promise: null, // Map-related fields ref: null, size: 0, staleAt, version: 0 }; return emptyEntry; } function upgradeToPendingSegment(emptyEntry, fetchStrategy) { const pendingEntry = emptyEntry; pendingEntry.status = 1; pendingEntry.fetchStrategy = fetchStrategy; // Set the version here, since this is right before the request is initiated. // The next time the global cache version is incremented, the entry will // effectively be evicted. This happens before initiating the request, rather // than when receiving the response, because it's guaranteed to happen // before the data is read on the server. pendingEntry.version = getCurrentCacheVersion(); return pendingEntry; } 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, renderedSearch, isPPREnabled, isHeadDynamic) { 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.renderedSearch = renderedSearch; fulfilledEntry.isPPREnabled = isPPREnabled; fulfilledEntry.TODO_isHeadDynamic = isHeadDynamic; 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, renderedPathname) { // Remove trailing and leading slashes const pathnameParts = renderedPathname.split('/').filter((p)=>p !== ''); const index = 0; const rootSegment = _segmentvalueencoding.ROOT_SEGMENT_CACHE_KEY; return convertTreePrefetchToRouteTree(rootTree.tree, rootSegment, null, _segmentvalueencoding.ROOT_SEGMENT_REQUEST_KEY, _segmentvalueencoding.ROOT_SEGMENT_CACHE_KEY, pathnameParts, index); } function convertTreePrefetchToRouteTree(prefetch, segment, param, requestKey, cacheKey, pathnameParts, pathnamePartsIndex) { // 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 childParamName = childPrefetch.name; const childParamType = childPrefetch.paramType; const childServerSentParamKey = childPrefetch.paramKey; let childDoesAppearInURL; let childParam = null; let childSegment; if (childParamType !== null) { // This segment is parameterized. Get the param from the pathname. const childParamValue = (0, _routeparams.parseDynamicParamFromURLPart)(childParamType, pathnameParts, pathnamePartsIndex); // Assign a cache key to the segment, based on the param value. In the // pre-Segment Cache implementation, the server computes this and sends // it in the body of the response. In the Segment Cache implementation, // the server sends an empty string and we fill it in here. // TODO: We're intentionally not adding the search param to page // segments here; it's tracked separately and added back during a read. // This would clearer if we waited to construct the segment until it's // read from the cache, since that's effectively what we're // doing anyway. const renderedSearch = ''; const childParamKey = // The server omits this field from the prefetch response when // cacheComponents is enabled. childServerSentParamKey !== null ? childServerSentParamKey : (0, _routeparams.getCacheKeyForDynamicParam)(childParamValue, renderedSearch); childParam = { name: childParamName, value: childParamValue, type: childParamType }; childSegment = [ childParamName, childParamKey, childParamType ]; childDoesAppearInURL = true; } else { childSegment = childParamName; childDoesAppearInURL = (0, _routeparams.doesStaticSegmentAppearInURL)(childParamName); } // Only increment the index if the segment appears in the URL. If it's a // "virtual" segment, like a route group, it remains the same. const childPathnamePartsIndex = childDoesAppearInURL ? pathnamePartsIndex + 1 : pathnamePartsIndex; const childRequestKeyPart = (0, _segmentvalueencoding.createSegmentRequestKeyPart)(childSegment); const childRequestKey = (0, _segmentvalueencoding.appendSegmentRequestKeyPart)(requestKey, parallelRouteKey, childRequestKeyPart); const childCacheKey = (0, _segmentvalueencoding.appendSegmentCacheKeyPart)(cacheKey, parallelRouteKey, (0, _segmentvalueencoding.createSegmentCacheKeyPart)(childRequestKeyPart, childSegment)); slots[parallelRouteKey] = convertTreePrefetchToRouteTree(childPrefetch, childSegment, childParam, childRequestKey, childCacheKey, pathnameParts, childPathnamePartsIndex); } } return { cacheKey, requestKey, segment, param, slots, isRootLayout: prefetch.isRootLayout, // This field is only relevant to dynamic routes. For a PPR/static route, // there's always some partial loading state we can fetch. hasLoadingBoundary: _approutertypes.HasLoadingBoundary.SegmentHasLoadingBoundary, hasRuntimePrefetch: prefetch.hasRuntimePrefetch }; } function convertRootFlightRouterStateToRouteTree(flightRouterState) { return convertFlightRouterStateToRouteTree(flightRouterState, _segmentvalueencoding.ROOT_SEGMENT_CACHE_KEY, _segmentvalueencoding.ROOT_SEGMENT_REQUEST_KEY); } function convertFlightRouterStateToRouteTree(flightRouterState, cacheKey, requestKey) { 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 childRequestKeyPart = (0, _segmentvalueencoding.createSegmentRequestKeyPart)(childSegment); const childRequestKey = (0, _segmentvalueencoding.appendSegmentRequestKeyPart)(requestKey, parallelRouteKey, childRequestKeyPart); const childCacheKey = (0, _segmentvalueencoding.appendSegmentCacheKeyPart)(cacheKey, parallelRouteKey, (0, _segmentvalueencoding.createSegmentCacheKeyPart)(childRequestKeyPart, childSegment)); const childTree = convertFlightRouterStateToRouteTree(childRouterState, childCacheKey, childRequestKey); if (slots === null) { slots = { [parallelRouteKey]: childTree }; } else { slots[parallelRouteKey] = childTree; } } const originalSegment = flightRouterState[0]; let segment; let param = null; if (Array.isArray(originalSegment)) { const paramCacheKey = originalSegment[1]; const paramType = originalSegment[2]; const paramValue = (0, _routeparams.getParamValueFromCacheKey)(paramCacheKey, paramType); param = { name: originalSegment[0], value: paramValue === undefined ? null : paramValue, type: originalSegment[2] }; segment = originalSegment; } else { // 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. segment = typeof originalSegment === 'string' && originalSegment.startsWith(_segment.PAGE_SEGMENT_KEY) ? _segment.PAGE_SEGMENT_KEY : originalSegment; } return { cacheKey, requestKey, segment, param, slots, isRootLayout: flightRouterState[4] === true, hasLoadingBoundary: flightRouterState[5] !== undefined ? flightRouterState[5] : _approutertypes.HasLoadingBoundary.SubtreeHasNoLoadingBoundary, // Non-static tree responses are only used by apps that haven't adopted // Cache Components. So this is always false. hasRuntimePrefetch: false }; } 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, key) { // 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 pathname = key.pathname; const search = key.search; 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; } try { const url = new URL(pathname + search, location.origin); let response; let urlAfterRedirects; if (isOutputExportMode) { // In output: "export" mode, we can't use headers to request a particular // segment. Instead, we encode the extra request information into the URL. // This is not part of the "public" interface of the app; it's an internal // Next.js implementation detail that the app developer should not need to // concern themselves with. // // For example, to request a segment: // // Path passed to <Link>: /path/to/page // Path passed to fetch: /path/to/page/__next-segments/_tree // // (This is not the exact protocol, just an illustration.) // // Before we do that, though, we need to account for redirects. Even in // output: "export" mode, a proxy might redirect the page to a different // location, but we shouldn't assume or expect that they also redirect all // the segment files, too. // // To check whether the page is redirected, we perform a range request of // the first N bytes of the HTML document. The canonical URL is determined // from the response. // // Then we can use the canonical URL to request the route tree. // // NOTE: We could embed the route tree into the HTML document, to avoid // a second request. We're not doing that currently because it would make // the HTML document larger and affect normal page loads. const htmlResponse = await fetch(url, { headers: { Range: _outputexportprefetchencoding.DOC_PREFETCH_RANGE_HEADER_VALUE } }); const partialHtml = await htmlResponse.text(); if (!(0, _outputexportprefetchencoding.doesExportedHtmlMatchBuildId)(partialHtml, (0, _appbuildid.getAppBuildId)())) { // The target page is not part of this app, or it belongs to a // different build. rejectRouteCacheEntry(entry, Date.now() + 10 * 1000); return null; } urlAfterRedirects = htmlResponse.redirected ? new URL(htmlResponse.url) : url; response = await fetchPrefetchResponse(addSegmentPathToUrlInOutputExportMode(urlAfterRedirects, segmentPath), headers); } else { // "Server" mode. We can use request headers instead of the pathname. // TODO: The eventual plan is to get rid of our custom request headers and // encode everything into the URL, using a similar strategy to the // "output: export" block above. response = await fetchPrefetchResponse(url, headers); urlAfterRedirects = response !== null && response.redirected ? new URL(response.url) : url; } 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)(urlAfterRedirects); // 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 = (0, _promisewithresolvers.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; // Regardless of the type of response, we will never receive dynamic // metadata as part of this prefetch request. const isHeadDynamic = false; if (routeIsPPREnabled) { const prefetchStream = createPrefetchResponseStream(response.body, closed.resolve, function onResponseSizeUpdate(size) { (0, _cachemap.setSizeInCacheMap)(entry, size); }); const serverData = await (0, _fetchserverresponse.createFromNextReadableStream)(prefetchStream, headers); 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. // TODO: We should cache the fact that this is an MPA navigation. rejectRouteCacheEntry(entry, Date.now() + 10 * 1000); return null; } // Get the params that were used to render the target page. These may // be different from the params in the request URL, if the page // was rewritten. const renderedPathname = (0, _routeparams.getRenderedPathname)(response); const renderedSearch = (0, _routeparams.getRenderedSearch)(response); const routeTree = convertRootTreePrefetchToRouteTree(serverData, renderedPathname); const staleTimeMs = getStaleTimeMs(serverData.staleTime); fulfillRouteCacheEntry(entry, routeTree, serverData.head, serverData.isHeadPartial, Date.now() + staleTimeMs, couldBeIntercepted, canonicalUrl, renderedSearch, routeIsPPREnabled, isHeadDynamic); } 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) { (0, _cachemap.setSizeInCacheMap)(entry, size); }); const serverData = await (0, _fetchserverresponse.createFromNextReadableStream)(prefetchStream, headers); 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. // TODO: We should cache the fact that this is an MPA navigation. rejectRouteCacheEntry(entry, Date.now() + 10 * 1000); return null; } writeDynamicTreeResponseIntoCache(Date.now(), task, // The non-PPR response format is what we'd get if we prefetched these segments // using the LoadingBoundary fetch strategy, so mark their cache entries accordingly. _segmentcache.FetchStrategy.LoadingBoundary, response, serverData, entry, couldBeIntercepted, canonicalUrl, routeIsPPREnabled); } if (!couldBeIntercepted) { // 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. The `set` implementation handles removing it from // its previous position in the cache. We don't need to do anything to // update the LRU, because the entry is already in it. // TODO: Treat this as an upsert — should check if an entry already // exists at the new keypath, and if so, whether we should keep that // one instead. const newKeypath = [ pathname, search, _cachemap.Fallback ]; const isRevalidation = false; (0, _cachemap.setInCacheMap)(routeCacheMap, newKeypath, entry, isRevalidation); } // 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, tree) { // 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, location.origin); const nextUrl = routeKey.nextUrl; const requestKey = tree.requestKey; const normalizedRequestKey = requestKey === _segmentvalueencoding.ROOT_SEGMENT_REQUEST_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. '