chore: migrate from wrapped sync.Pool to HashTrieMap

This should lower memory consumption because HashTrieMap doesn't use any and doesn't have double maps.

Signed-off-by: Dmitriy Matrenichev <dmitry.matrenichev@siderolabs.com>

.golangci.yml

@@ -1,6 +1,6 @@
 # THIS FILE WAS AUTOMATICALLY GENERATED, PLEASE DO NOT EDIT.
 #
-# Generated on 2024-05-19T19:39:10Z by kres dccd292.
+# Generated on 2024-05-28T08:54:28Z by kres a914cae.
 
 # options for analysis running
 run:
@@ -13,8 +13,8 @@ run:
 # output configuration options
 output:
   formats:
-  - format: colored-line-number
-    path: stdout
+    - format: colored-line-number
+      path: stdout
   print-issued-lines: true
   print-linter-name: true
   uniq-by-line: true
@@ -94,17 +94,21 @@ linters-settings:
   cyclop:
     # the maximal code complexity to report
     max-complexity: 20
-  #  depguard:
-  #    Main:
-  #      deny:
-  #        - github.com/OpenPeeDeeP/depguard # this is just an example
+  depguard:
+    rules:
+      prevent_unmaintained_packages:
+        list-mode: lax # allow unless explicitly denied
+        files:
+          - $all
+        deny:
+          - pkg: io/ioutil
+            desc: "replaced by io and os packages since Go 1.16: https://tip.golang.org/doc/go1.16#ioutil"
 
 linters:
   enable-all: true
   disable-all: false
   fast: false
   disable:
-    - exhaustivestruct
     - exhaustruct
     - err113
     - forbidigo
@@ -120,30 +124,17 @@ linters:
     - mnd
     - nestif
     - nonamedreturns
-    - nosnakecase
     - paralleltest
     - tagalign
     - tagliatelle
     - thelper
-    - typecheck
     - varnamelen
     - wrapcheck
-    - depguard # Disabled because starting with golangci-lint 1.53.0 it doesn't allow denylist alone anymore
     - testifylint # complains about our assert recorder and has a number of false positives for assert.Greater(t, thing, 1)
     - protogetter # complains about us using Value field on typed spec, instead of GetValue which has a different signature
     - perfsprint # complains about us using fmt.Sprintf in non-performance critical code, updating just kres took too long
-    # abandoned linters for which golangci shows the warning that the repo is archived by the owner
-    - deadcode
-    - golint
-    - ifshort
-    - interfacer
-    - maligned
-    - scopelint
-    - structcheck
-    - varcheck
-    # disabled as it seems to be broken - goes into imported libraries and reports issues there
-    - musttag
     - goimports # same as gci
+    - musttag # seems to be broken - goes into imported libraries and reports issues there
 
 issues:
   exclude: [ ]

internal/state/snapshot.go

@@ -6,6 +6,7 @@
 package state
 
 import (
+	"fmt"
 	"slices"
 
 	"github.com/siderolabs/gen/xslices"
@@ -23,7 +24,7 @@ func (state *State) ExportClusterSnapshots(f func(snapshot *storagepb.ClusterSna
 	// reuse the same snapshotin each iteration
 	clusterSnapshot := &storagepb.ClusterSnapshot{}
 
-	state.clusters.Range(func(_ string, cluster *Cluster) bool {
+	state.clusters.Enumerate(func(_ string, cluster *Cluster) bool {
 		snapshotCluster(cluster, clusterSnapshot)
 
 		err = f(clusterSnapshot)
@@ -50,7 +51,10 @@ func (state *State) ImportClusterSnapshots(f func() (*storagepb.ClusterSnapshot,
 
 		cluster := clusterFromSnapshot(clusterSnapshot)
 
-		state.clusters.Store(cluster.id, cluster)
+		_, loaded := state.clusters.LoadOrStore(cluster.id, cluster)
+		if loaded {
+			return fmt.Errorf("cluster %q already exists", cluster.id)
+		}
 	}
 
 	return nil

internal/state/state.go

@@ -11,13 +11,13 @@ import (
 	"time"
 
 	prom "github.com/prometheus/client_golang/prometheus"
-	"github.com/siderolabs/gen/containers"
+	"github.com/siderolabs/gen/concurrent"
 	"go.uber.org/zap"
 )
 
 // State keeps the discovery service state.
-type State struct { //nolint:govet
-	clusters containers.SyncMap[string, *Cluster]
+type State struct {
+	clusters *concurrent.HashTrieMap[string, *Cluster]
 	logger   *zap.Logger
 
 	mClustersDesc      *prom.Desc
@@ -32,7 +32,8 @@ type State struct { //nolint:govet
 // NewState create new instance of State.
 func NewState(logger *zap.Logger) *State {
 	return &State{
-		logger: logger,
+		clusters: concurrent.NewHashTrieMap[string, *Cluster](),
+		logger:   logger,
 		mClustersDesc: prom.NewDesc(
 			"discovery_state_clusters",
 			"The current number of clusters in the state.",
@@ -84,12 +85,12 @@ func (state *State) GetCluster(id string) *Cluster {
 
 // GarbageCollect recursively each cluster, and remove empty clusters.
 func (state *State) GarbageCollect(now time.Time) (removedClusters, removedAffiliates int) {
-	state.clusters.Range(func(key string, cluster *Cluster) bool {
+	state.clusters.Enumerate(func(key string, cluster *Cluster) bool {
 		ra, empty := cluster.GarbageCollect(now)
 		removedAffiliates += ra
 
 		if empty {
-			state.clusters.Delete(key)
+			state.clusters.CompareAndDelete(key, cluster)
 			state.logger.Debug("cluster removed", zap.String("cluster_id", key))
 
 			removedClusters++
@@ -137,7 +138,7 @@ func (state *State) RunGC(ctx context.Context, logger *zap.Logger, interval time
 }
 
 func (state *State) stats() (clusters, affiliates, endpoints, subscriptions int) {
-	state.clusters.Range(func(_ string, cluster *Cluster) bool {
+	state.clusters.Enumerate(func(_ string, cluster *Cluster) bool {
 		clusters++
 
 		a, e, s := cluster.stats()