diff options
Diffstat (limited to 'internal/timeline/get.go')
| -rw-r--r-- | internal/timeline/get.go | 428 |
1 files changed, 0 insertions, 428 deletions
diff --git a/internal/timeline/get.go b/internal/timeline/get.go deleted file mode 100644 index 06ee8c174..000000000 --- a/internal/timeline/get.go +++ /dev/null @@ -1,428 +0,0 @@ -// GoToSocial -// Copyright (C) GoToSocial Authors admin@gotosocial.org -// SPDX-License-Identifier: AGPL-3.0-or-later -// -// This program is free software: you can redistribute it and/or modify -// it under the terms of the GNU Affero General Public License as published by -// the Free Software Foundation, either version 3 of the License, or -// (at your option) any later version. -// -// This program is distributed in the hope that it will be useful, -// but WITHOUT ANY WARRANTY; without even the implied warranty of -// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -// GNU Affero General Public License for more details. -// -// You should have received a copy of the GNU Affero General Public License -// along with this program. If not, see <http://www.gnu.org/licenses/>. - -package timeline - -import ( - "container/list" - "context" - "errors" - "time" - - "codeberg.org/gruf/go-kv" - "github.com/superseriousbusiness/gotosocial/internal/db" - statusfilter "github.com/superseriousbusiness/gotosocial/internal/filter/status" - "github.com/superseriousbusiness/gotosocial/internal/gtserror" - "github.com/superseriousbusiness/gotosocial/internal/id" - "github.com/superseriousbusiness/gotosocial/internal/log" -) - -func (t *timeline) LastGot() time.Time { - t.Lock() - defer t.Unlock() - return t.lastGot -} - -func (t *timeline) Get(ctx context.Context, amount int, maxID string, sinceID string, minID string, prepareNext bool) ([]Preparable, error) { - l := log.WithContext(ctx). - WithFields(kv.Fields{ - {"accountID", t.timelineID}, - {"amount", amount}, - {"maxID", maxID}, - {"sinceID", sinceID}, - {"minID", minID}, - }...) - l.Trace("entering get and updating t.lastGot") - - // Regardless of what happens below, update the - // last time Get was called for this timeline. - t.Lock() - t.lastGot = time.Now() - t.Unlock() - - var ( - items []Preparable - err error - ) - - switch { - case maxID == "" && sinceID == "" && minID == "": - // No params are defined so just fetch from the top. - // This is equivalent to a user starting to view - // their timeline from newest -> older posts. - items, err = t.getXBetweenIDs(ctx, amount, id.Highest, id.Lowest, true) - - // Cache expected next query to speed up scrolling. - // Assume the user will be scrolling downwards from - // the final ID in items. - if prepareNext && err == nil && len(items) != 0 { - nextMaxID := items[len(items)-1].GetID() - t.prepareNextQuery(amount, nextMaxID, "", "") - } - - case maxID != "" && sinceID == "" && minID == "": - // Only maxID is defined, so fetch from maxID onwards. - // This is equivalent to a user paging further down - // their timeline from newer -> older posts. - items, err = t.getXBetweenIDs(ctx, amount, maxID, id.Lowest, true) - - // Cache expected next query to speed up scrolling. - // Assume the user will be scrolling downwards from - // the final ID in items. - if prepareNext && err == nil && len(items) != 0 { - nextMaxID := items[len(items)-1].GetID() - t.prepareNextQuery(amount, nextMaxID, "", "") - } - - // In the next cases, maxID is defined, and so are - // either sinceID or minID. This is equivalent to - // a user opening an in-progress timeline and asking - // for a slice of posts somewhere in the middle, or - // trying to "fill in the blanks" between two points, - // paging either up or down. - case maxID != "" && sinceID != "": - items, err = t.getXBetweenIDs(ctx, amount, maxID, sinceID, true) - - // Cache expected next query to speed up scrolling. - // We can assume the caller is scrolling downwards. - // Guess id.Lowest as sinceID, since we don't actually - // know what the next sinceID would be. - if prepareNext && err == nil && len(items) != 0 { - nextMaxID := items[len(items)-1].GetID() - t.prepareNextQuery(amount, nextMaxID, id.Lowest, "") - } - - case maxID != "" && minID != "": - items, err = t.getXBetweenIDs(ctx, amount, maxID, minID, false) - - // Cache expected next query to speed up scrolling. - // We can assume the caller is scrolling upwards. - // Guess id.Highest as maxID, since we don't actually - // know what the next maxID would be. - if prepareNext && err == nil && len(items) != 0 { - prevMinID := items[0].GetID() - t.prepareNextQuery(amount, id.Highest, "", prevMinID) - } - - // In the final cases, maxID is not defined, but - // either sinceID or minID are. This is equivalent to - // a user either "pulling up" at the top of their timeline - // to refresh it and check if newer posts have come in, or - // trying to scroll upwards from an old post to see what - // they missed since then. - // - // In these calls, we use the highest possible ulid as - // behindID because we don't have a cap for newest that - // we're interested in. - case maxID == "" && sinceID != "": - items, err = t.getXBetweenIDs(ctx, amount, id.Highest, sinceID, true) - - // We can't cache an expected next query for this one, - // since presumably the caller is at the top of their - // timeline already. - - case maxID == "" && minID != "": - items, err = t.getXBetweenIDs(ctx, amount, id.Highest, minID, false) - - // Cache expected next query to speed up scrolling. - // We can assume the caller is scrolling upwards. - // Guess id.Highest as maxID, since we don't actually - // know what the next maxID would be. - if prepareNext && err == nil && len(items) != 0 { - prevMinID := items[0].GetID() - t.prepareNextQuery(amount, id.Highest, "", prevMinID) - } - - default: - err = gtserror.New("switch statement exhausted with no results") - } - - return items, err -} - -// getXBetweenIDs returns x amount of items somewhere between (not including) the given IDs. -// -// If frontToBack is true, items will be served paging down from behindID. -// This corresponds to an api call to /timelines/home?max_id=WHATEVER&since_id=WHATEVER -// -// If frontToBack is false, items will be served paging up from beforeID. -// This corresponds to an api call to /timelines/home?max_id=WHATEVER&min_id=WHATEVER -func (t *timeline) getXBetweenIDs(ctx context.Context, amount int, behindID string, beforeID string, frontToBack bool) ([]Preparable, error) { - l := log. - WithContext(ctx). - WithFields(kv.Fields{ - {"amount", amount}, - {"behindID", behindID}, - {"beforeID", beforeID}, - {"frontToBack", frontToBack}, - }...) - l.Trace("entering getXBetweenID") - - // Assume length we need to return. - items := make([]Preparable, 0, amount) - - if beforeID >= behindID { - // This is an impossible situation, we - // can't serve anything between these. - return items, nil - } - - // Try to ensure we have enough items prepared. - if err := t.prepareXBetweenIDs(ctx, amount, behindID, beforeID, frontToBack); err != nil { - // An error here doesn't necessarily mean we - // can't serve anything, so log + keep going. - l.Debugf("error calling prepareXBetweenIDs: %s", err) - } - - var ( - beforeIDMark *list.Element - served int - // Our behavior while ranging through the - // list changes depending on if we're - // going front-to-back or back-to-front. - // - // To avoid checking which one we're doing - // in each loop iteration, define our range - // function here outside the loop. - // - // The bool indicates to the caller whether - // iteration should continue (true) or stop - // (false). - rangeF func(e *list.Element) (bool, error) - // If we get certain errors on entries as we're - // looking through, we might want to cheekily - // remove their elements from the timeline. - // Everything added to this slice will be removed. - removeElements = []*list.Element{} - ) - - defer func() { - for _, e := range removeElements { - t.items.data.Remove(e) - } - }() - - if frontToBack { - // We're going front-to-back, which means we - // don't need to look for a mark per se, we - // just keep serving items until we've reached - // a point where the items are out of the range - // we're interested in. - rangeF = func(e *list.Element) (bool, error) { - entry := e.Value.(*indexedItemsEntry) - - if entry.itemID >= behindID { - // ID of this item is too high, - // just keep iterating. - l.Trace("item is too new, continuing") - return true, nil - } - - if entry.itemID <= beforeID { - // We've gone as far as we can through - // the list and reached entries that are - // now too old for us, stop here. - l.Trace("reached older items, breaking") - return false, nil - } - - l.Trace("entry is just right") - - if entry.prepared == nil { - // Whoops, this entry isn't prepared yet; some - // race condition? That's OK, we can do it now. - prepared, err := t.prepareFunction(ctx, t.timelineID, entry.itemID) - if err != nil { - if errors.Is(err, statusfilter.ErrHideStatus) { - // This item has been filtered out by the requesting user's filters. - // Remove it and skip past it. - removeElements = append(removeElements, e) - return true, nil - } - if errors.Is(err, db.ErrNoEntries) { - // ErrNoEntries means something has been deleted, - // so we'll likely not be able to ever prepare this. - // This means we can remove it and skip past it. - l.Debugf("db.ErrNoEntries while trying to prepare %s; will remove from timeline", entry.itemID) - removeElements = append(removeElements, e) - return true, nil - } - // We've got a proper db error. - err = gtserror.Newf("db error while trying to prepare %s: %w", entry.itemID, err) - return false, err - } - entry.prepared = prepared - } - - items = append(items, entry.prepared) - - served++ - return served < amount, nil - } - } else { - // Iterate through the list from the top, until - // we reach an item with id smaller than beforeID; - // ie., an item OLDER than beforeID. At that point, - // we can stop looking because we're not interested - // in older entries. - rangeF = func(e *list.Element) (bool, error) { - // Move the mark back one place each loop. - beforeIDMark = e - - if entry := e.Value.(*indexedItemsEntry); entry.itemID <= beforeID { - // We've gone as far as we can through - // the list and reached entries that are - // now too old for us, stop here. - l.Trace("reached older items, breaking") - return false, nil - } - - return true, nil - } - } - - // Iterate through the list until the function - // we defined above instructs us to stop. - for e := t.items.data.Front(); e != nil; e = e.Next() { - keepGoing, err := rangeF(e) - if err != nil { - return nil, err - } - - if !keepGoing { - break - } - } - - if frontToBack || beforeIDMark == nil { - // If we're serving front to back, then - // items should be populated by now. If - // we're serving back to front but didn't - // find any items newer than beforeID, - // we can just return empty items. - return items, nil - } - - // We're serving back to front, so iterate upwards - // towards the front of the list from the mark we found, - // until we either get to the front, serve enough - // items, or reach behindID. - // - // To preserve ordering, we need to reverse the slice - // when we're finished. - for e := beforeIDMark; e != nil; e = e.Prev() { - entry := e.Value.(*indexedItemsEntry) - - if entry.itemID == beforeID { - // Don't include the beforeID - // entry itself, just continue. - l.Trace("entry item ID is equal to beforeID, skipping") - continue - } - - if entry.itemID >= behindID { - // We've reached items that are - // newer than what we're looking - // for, just stop here. - l.Trace("reached newer items, breaking") - break - } - - if entry.prepared == nil { - // Whoops, this entry isn't prepared yet; some - // race condition? That's OK, we can do it now. - prepared, err := t.prepareFunction(ctx, t.timelineID, entry.itemID) - if err != nil { - if errors.Is(err, statusfilter.ErrHideStatus) { - // This item has been filtered out by the requesting user's filters. - // Remove it and skip past it. - removeElements = append(removeElements, e) - continue - } - if errors.Is(err, db.ErrNoEntries) { - // ErrNoEntries means something has been deleted, - // so we'll likely not be able to ever prepare this. - // This means we can remove it and skip past it. - l.Debugf("db.ErrNoEntries while trying to prepare %s; will remove from timeline", entry.itemID) - removeElements = append(removeElements, e) - continue - } - // We've got a proper db error. - err = gtserror.Newf("db error while trying to prepare %s: %w", entry.itemID, err) - return nil, err - } - entry.prepared = prepared - } - - items = append(items, entry.prepared) - - served++ - if served >= amount { - break - } - } - - // Reverse order of items. - // https://zchee.github.io/golang-wiki/SliceTricks/#reversing - for l, r := 0, len(items)-1; l < r; l, r = l+1, r-1 { - items[l], items[r] = items[r], items[l] - } - - return items, nil -} - -func (t *timeline) prepareNextQuery(amount int, maxID string, sinceID string, minID string) { - var ( - // We explicitly use context.Background() rather than - // accepting a context param because we don't want this - // to stop/break when the calling context finishes. - ctx = context.Background() - err error - ) - - // Always perform this async so caller doesn't have to wait. - go func() { - switch { - case maxID == "" && sinceID == "" && minID == "": - err = t.prepareXBetweenIDs(ctx, amount, id.Highest, id.Lowest, true) - case maxID != "" && sinceID == "" && minID == "": - err = t.prepareXBetweenIDs(ctx, amount, maxID, id.Lowest, true) - case maxID != "" && sinceID != "": - err = t.prepareXBetweenIDs(ctx, amount, maxID, sinceID, true) - case maxID != "" && minID != "": - err = t.prepareXBetweenIDs(ctx, amount, maxID, minID, false) - case maxID == "" && sinceID != "": - err = t.prepareXBetweenIDs(ctx, amount, id.Highest, sinceID, true) - case maxID == "" && minID != "": - err = t.prepareXBetweenIDs(ctx, amount, id.Highest, minID, false) - default: - err = gtserror.New("switch statement exhausted with no results") - } - - if err != nil { - log. - WithContext(ctx). - WithFields(kv.Fields{ - {"amount", amount}, - {"maxID", maxID}, - {"sinceID", sinceID}, - {"minID", minID}, - }...). - Warnf("error preparing next query: %s", err) - } - }() -} |