[performance] refactoring + add fave / follow / request / visibility caching (#1607)

* refactor visibility checking, add caching for visibility

* invalidate visibility cache items on account / status deletes

* fix requester ID passed to visibility cache nil ptr

* de-interface caches, fix home / public timeline caching + visibility

* finish adding code comments for visibility filter

* fix angry goconst linter warnings

* actually finish adding filter visibility code comments for timeline functions

* move home timeline status author check to after visibility

* remove now-unused code

* add more code comments

* add TODO code comment, update printed cache start names

* update printed cache names on stop

* start adding separate follow(request) delete db functions, add specific visibility cache tests

* add relationship type caching

* fix getting local account follows / followed-bys, other small codebase improvements

* simplify invalidation using cache hooks, add more GetAccountBy___() functions

* fix boosting to return 404 if not boostable but no error (to not leak status ID)

* remove dead code

* improved placement of cache invalidation

* update license headers

* add example follow, follow-request config entries

* add example visibility cache configuration to config file

* use specific PutFollowRequest() instead of just Put()

* add tests for all GetAccountBy()

* add GetBlockBy() tests

* update block to check primitive fields

* update and finish adding Get{Account,Block,Follow,FollowRequest}By() tests

* fix copy-pasted code

* update envparsing test

* whitespace

* fix bun struct tag

* add license header to gtscontext

* fix old license header

* improved error creation to not use fmt.Errorf() when not needed

* fix various rebase conflicts, fix account test

* remove commented-out code, fix-up mention caching

* fix mention select bun statement

* ensure mention target account populated, pass in context to customrenderer logging

* remove more uncommented code, fix typeutil test

* add statusfave database model caching

* add status fave cache configuration

* add status fave cache example config

* woops, catch missed error. nice catch linter!

* add back testrig panic on nil db

* update example configuration to match defaults, slight tweak to cache configuration defaults

* update envparsing test with new defaults

* fetch followingget to use the follow target account

* use accounnt.IsLocal() instead of empty domain check

* use constants for the cache visibility type check

* use bun.In() for notification type restriction in db query

* include replies when fetching PublicTimeline() (to account for single-author threads in Visibility{}.StatusPublicTimelineable())

* use bun query building for nested select statements to ensure working with postgres

* update public timeline future status checks to match visibility filter

* same as previous, for home timeline

* update public timeline tests to dynamically check for appropriate statuses

* migrate accounts to allow unique constraint on public_key

* provide minimal account with publicKey

---------

Signed-off-by: kim <grufwub@gmail.com>
Co-authored-by: tsmethurst <tobi.smethurst@protonmail.com>

internal/cache/util.go

@@ -17,7 +17,30 @@
 
 package cache
 
-import "github.com/superseriousbusiness/gotosocial/internal/log"
+import (
+	"context"
+	"errors"
+	"fmt"
+	"time"
+
+	"codeberg.org/gruf/go-cache/v3/result"
+	errorsv2 "codeberg.org/gruf/go-errors/v2"
+	"github.com/superseriousbusiness/gotosocial/internal/log"
+)
+
+// SentinelError is returned to indicate a non-permanent error return,
+// i.e. a situation in which we do not want a cache a negative result.
+var SentinelError = errors.New("BUG: error should not be returned") //nolint:revive
+
+// ignoreErrors is an error ignoring function capable of being passed to
+// caches, which specifically catches and ignores our sentinel error type.
+func ignoreErrors(err error) bool {
+	return errorsv2.Is(
+		SentinelError,
+		context.DeadlineExceeded,
+		context.Canceled,
+	)
+}
 
 // nocopy when embedded will signal linter to
 // error on pass-by-value of parent struct.
@@ -27,6 +50,26 @@ func (*nocopy) Lock() {}
 
 func (*nocopy) Unlock() {}
 
+// tryStart will attempt to start the given cache only if sweep duration > 0 (sweeping is enabled).
+func tryStart[ValueType any](cache *result.Cache[ValueType], sweep time.Duration) {
+	if sweep > 0 {
+		var z ValueType
+		msg := fmt.Sprintf("starting %T cache", z)
+		tryUntil(msg, 5, func() bool {
+			return cache.Start(sweep)
+		})
+	}
+}
+
+// tryStop will attempt to stop the given cache only if sweep duration > 0 (sweeping is enabled).
+func tryStop[ValueType any](cache *result.Cache[ValueType], sweep time.Duration) {
+	if sweep > 0 {
+		var z ValueType
+		msg := fmt.Sprintf("stopping %T cache", z)
+		tryUntil(msg, 5, cache.Stop)
+	}
+}
+
 // tryUntil will attempt to call 'do' for 'count' attempts, before panicking with 'msg'.
 func tryUntil(msg string, count int, do func() bool) {
 	for i := 0; i < count; i++ {