Storage: Add new resource module and move some utilities (#89443)

.github/CODEOWNERS

@@ -107,6 +107,7 @@
 /pkg/apimachinery/identity/ @grafana/identity-squad
 /pkg/apimachinery/errutil/ @grafana/grafana-backend-group
 /pkg/promlib @grafana/observability-metrics
+/pkg/storage/ @grafana/grafana-search-and-storage
 /pkg/services/annotations/ @grafana/grafana-search-and-storage
 /pkg/services/apikey/ @grafana/identity-squad
 /pkg/services/cleanup/ @grafana/grafana-backend-group

go.work

@@ -7,6 +7,7 @@ use (
 	./pkg/build
 	./pkg/build/wire
 	./pkg/promlib
+	./pkg/storage/unified/resource
 	./pkg/util/xorm
 )
 

go.work.sum

@@ -942,6 +942,7 @@ github.com/grafana/grafana-plugin-sdk-go v0.228.0/go.mod h1:u4K9vVN6eU86loO68977
 github.com/grafana/grafana-plugin-sdk-go v0.229.0/go.mod h1:6V6ikT4ryva8MrAp7Bdz5fTJx3/ztzKvpMJFfpzr4CI=
 github.com/grafana/grafana-plugin-sdk-go v0.231.1-0.20240523124942-62dae9836284/go.mod h1:bNgmNmub1I7Mc8dzIncgNqHC5jTgSZPPHlZ3aG8HKJQ=
 github.com/grafana/grafana-plugin-sdk-go v0.234.0/go.mod h1:FlXjmBESxaD6Hoi8ojWLkH007nyjtJM3XC8SpwzF/YE=
+github.com/grafana/grafana/pkg/apimachinery v0.0.0-20240613114114-5e2f08de316d/go.mod h1:adT8O7k6ZSzUKjAC4WS6VfWlCE4G1VavPwSXVhvScCs=
 github.com/grafana/grafana/pkg/promlib v0.0.3/go.mod h1:3El4NlsfALz8QQCbEGHGFvJUG+538QLMuALRhZ3pcoo=
 github.com/gregjones/httpcache v0.0.0-20180305231024-9cad4c3443a7 h1:pdN6V1QBWetyv/0+wjACpqVH+eVULgEjkurDLq3goeM=
 github.com/grpc-ecosystem/go-grpc-middleware v1.0.0/go.mod h1:FiyG127CGDf3tlThmgyCl78X/SZQqEOJBCDaAfeWzPs=

pkg/services/store/entity/sqlstash/sql_storage_server.go

@@ -25,6 +25,7 @@ import (
 	"github.com/grafana/grafana/pkg/services/store/entity"
 	"github.com/grafana/grafana/pkg/services/store/entity/db"
 	"github.com/grafana/grafana/pkg/services/store/entity/sqlstash/sqltemplate"
+	"github.com/grafana/grafana/pkg/storage/unified/resource"
 )
 
 const entityTable = "entity"
@@ -75,7 +76,7 @@ type sqlEntityServer struct {
 	db          db.EntityDBInterface // needed to keep xorm engine in scope
 	sess        *session.SessionDB
 	dialect     migrator.Dialect
-	broadcaster Broadcaster[*entity.EntityWatchResponse]
+	broadcaster resource.Broadcaster[*entity.EntityWatchResponse]
 	ctx         context.Context // TODO: remove
 	cancel      context.CancelFunc
 	tracer      trace.Tracer
@@ -141,7 +142,7 @@ func (s *sqlEntityServer) init() error {
 	s.dialect = migrator.NewDialect(engine.DriverName())
 
 	// set up the broadcaster
-	s.broadcaster, err = NewBroadcaster(s.ctx, func(stream chan<- *entity.EntityWatchResponse) error {
+	s.broadcaster, err = resource.NewBroadcaster(s.ctx, func(stream chan<- *entity.EntityWatchResponse) error {
 		// start the poller
 		go s.poller(stream)
 

pkg/storage/unified/resource/broadcaster.go

@@ -1,4 +1,4 @@
-package sqlstash
+package resource
 
 import (
 	"context"
@@ -109,7 +109,7 @@ type broadcaster[T any] struct {
 
 	// subscription management
 
-	cache       Cache[T]
+	cache       channelCache[T]
 	subscribe   chan chan T
 	unsubscribe chan (<-chan T)
 	subs        map[<-chan T]chan T
@@ -166,7 +166,7 @@ func (b *broadcaster[T]) init(ctx context.Context, connect ConnectFunc[T]) error
 
 	// initialize our internal state
 	b.shouldTerminate = ctx.Done()
-	b.cache = NewCache[T](ctx, 100)
+	b.cache = newChannelCache[T](ctx, 100)
 	b.subscribe = make(chan chan T, 100)
 	b.unsubscribe = make(chan (<-chan T), 100)
 	b.subs = make(map[<-chan T]chan T)
@@ -239,9 +239,9 @@ func (b *broadcaster[T]) stream(input <-chan T) {
 	}
 }
 
-const DefaultCacheSize = 100
+const defaultCacheSize = 100
 
-type Cache[T any] interface {
+type channelCache[T any] interface {
 	Len() int
 	Add(item T)
 	Get(i int) T
@@ -260,12 +260,12 @@ type cache[T any] struct {
 	ctx       context.Context
 }
 
-func NewCache[T any](ctx context.Context, size int) Cache[T] {
+func newChannelCache[T any](ctx context.Context, size int) channelCache[T] {
 	c := &cache[T]{}
 
 	c.ctx = ctx
 	if size <= 0 {
-		size = DefaultCacheSize
+		size = defaultCacheSize
 	}
 	c.size = size
 	c.cache = make([]T, c.size)

pkg/storage/unified/resource/broadcaster_test.go

@@ -1,4 +1,4 @@
-package sqlstash
+package resource
 
 import (
 	"context"
@@ -8,7 +8,7 @@ import (
 )
 
 func TestCache(t *testing.T) {
-	c := NewCache[int](context.Background(), 10)
+	c := newChannelCache[int](context.Background(), 10)
 
 	e := []int{}
 	err := c.Range(func(i int) error {

pkg/storage/unified/resource/go.mod

@@ -0,0 +1,14 @@
+module github.com/grafana/grafana/pkg/storage/unified/resource
+
+go 1.21.10
+
+require github.com/stretchr/testify v1.9.0
+
+require (
+	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
+	github.com/kr/pretty v0.3.1 // indirect
+	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
+	github.com/rogpeppe/go-internal v1.12.0 // indirect
+	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

pkg/storage/unified/resource/go.sum

@@ -0,0 +1,8 @@
+github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
+github.com/rogpeppe/go-internal v1.12.0 h1:exVL4IDcn6na9z1rAb56Vxr+CgyK3nn3O+epU5NdKM8=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=