[performance] update remaining worker pools to use queues (#2865)

* start replacing client + federator + media workers with new worker + queue types

* refactor federatingDB.Delete(), drop queued messages when deleting account / status

* move all queue purging to the processor workers

* undo toolchain updates

* code comments, ensure dereferencer worker pool gets started

* update gruf libraries in readme

* start the job scheduler separately to the worker pools

* reshuffle ordering or server.go + remove duplicate worker start / stop

* update go-list version

* fix vendoring

* move queue invalidation to before wipeing / deletion, to ensure queued work not dropped

* add logging to worker processing functions in testrig, don't start workers in unexpected places

* update go-structr to add (+then rely on) QueueCtx{} type

* ensure more worker pools get started properly in tests

* fix remaining broken tests relying on worker queue logic

* fix account test suite queue popping logic, ensure noop workers do not pull from queue

* move back accidentally shuffled account deletion order

* ensure error (non nil!!) gets passed in refactored federatingDB{}.Delete()

* silently drop deletes from accounts not permitted to

* don't warn log on forwarded deletes

* make if else clauses easier to parse

* use getFederatorMsg()

* improved code comment

* improved code comment re: requesting account delete checks

* remove boolean result from worker start / stop since false = already running or already stopped

* remove optional passed-in http.client

* remove worker starting from the admin CLI commands (we don't need to handle side-effects)

* update prune cli to start scheduler but not all of the workers

* fix rebase issues

* remove redundant return statements

* i'm sorry sir linter

internal/transport/delivery/delivery.go

@@ -28,6 +28,7 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/httpclient"
 	"github.com/superseriousbusiness/gotosocial/internal/log"
 	"github.com/superseriousbusiness/gotosocial/internal/queue"
+	"github.com/superseriousbusiness/gotosocial/internal/util"
 )
 
 // Delivery wraps an httpclient.Request{}
@@ -99,29 +100,51 @@ func (p *WorkerPool) Init(client *httpclient.Client) {
 }
 
 // Start will attempt to start 'n' Worker{}s.
-func (p *WorkerPool) Start(n int) (ok bool) {
-	if ok = (len(p.workers) == 0); ok {
-		p.workers = make([]*Worker, n)
-		for i := range p.workers {
-			p.workers[i] = new(Worker)
-			p.workers[i].Client = p.Client
-			p.workers[i].Queue = &p.Queue
-			ok = p.workers[i].Start() && ok
-		}
+func (p *WorkerPool) Start(n int) {
+	// Check whether workers are
+	// set (is already running).
+	ok := (len(p.workers) > 0)
+	if ok {
+		return
+	}
+
+	// Allocate new workers slice.
+	p.workers = make([]*Worker, n)
+	for i := range p.workers {
+
+		// Allocate new Worker{}.
+		p.workers[i] = new(Worker)
+		p.workers[i].Client = p.Client
+		p.workers[i].Queue = &p.Queue
+
+		// Attempt to start worker.
+		// Return bool not useful
+		// here, as true = started,
+		// false = already running.
+		_ = p.workers[i].Start()
 	}
-	return
 }
 
 // Stop will attempt to stop contained Worker{}s.
-func (p *WorkerPool) Stop() (ok bool) {
-	if ok = (len(p.workers) > 0); ok {
-		for i := range p.workers {
-			ok = p.workers[i].Stop() && ok
-			p.workers[i] = nil
-		}
-		p.workers = p.workers[:0]
+func (p *WorkerPool) Stop() {
+	// Check whether workers are
+	// set (is currently running).
+	ok := (len(p.workers) == 0)
+	if ok {
+		return
 	}
-	return
+
+	// Stop all running workers.
+	for i := range p.workers {
+
+		// return bool not useful
+		// here, as true = stopped,
+		// false = never running.
+		_ = p.workers[i].Stop()
+	}
+
+	// Unset workers slice.
+	p.workers = p.workers[:0]
 }
 
 // Worker wraps an httpclient.Client{} to feed
@@ -158,23 +181,13 @@ func (w *Worker) run(ctx context.Context) {
 	if w.Client == nil || w.Queue == nil {
 		panic("not yet initialized")
 	}
-	log.Infof(ctx, "%p: started delivery worker", w)
-	defer log.Infof(ctx, "%p: stopped delivery worker", w)
-	for returned := false; !returned; {
-		func() {
-			defer func() {
-				if r := recover(); r != nil {
-					log.Errorf(ctx, "recovered panic: %v", r)
-				}
-			}()
-			w.process(ctx)
-			returned = true
-		}()
-	}
+	log.Infof(ctx, "%p: starting worker", w)
+	defer log.Infof(ctx, "%p: stopped worker", w)
+	util.Must(func() { w.process(ctx) })
 }
 
 // process is the main delivery worker processing routine.
-func (w *Worker) process(ctx context.Context) {
+func (w *Worker) process(ctx context.Context) bool {
 	if w.Client == nil || w.Queue == nil {
 		// we perform this check here just
 		// to ensure the compiler knows these
@@ -188,7 +201,7 @@ loop:
 		// Get next delivery.
 		dlv, ok := w.next(ctx)
 		if !ok {
-			return
+			return true
 		}
 
 		// Check whether backoff required.
@@ -203,7 +216,7 @@ loop:
 				// Main ctx
 				// cancelled.
 				backoff.Stop()
-				return
+				return true
 
 			case <-w.Queue.Wait():
 				// A new message was

internal/transport/delivery/delivery_test.go

@@ -32,9 +32,7 @@ func testDeliveryWorkerPool(t *testing.T, sz int, input []*testrequest) {
 			"127.0.0.0/8",
 		}),
 	}))
-	if !wp.Start(sz) {
-		t.Fatal("failed starting pool")
-	}
+	wp.Start(sz)
 	defer wp.Stop()
 	test(t, &wp.Queue, input)
 }