Replace fastrand with rand/v2 package

Signed-off-by: Amirali Amirifar <amirali.amirifar@gmail.com>

Author: Amirali-Amirifar

internal/fastrand/LICENSE

@@ -22,7 +22,7 @@ import (
 	"io"
 	"io/fs"
 	"math"
-	"math/rand"
+	"math/rand/v2"
 	"net/http"
 	"net/textproto"
 	"reflect"
@@ -34,7 +34,6 @@ import (
 	"time"
 
 	"github.com/nats-io/jwt/v2"
-	"github.com/nats-io/nats-server/v2/internal/fastrand"
 	"github.com/nats-io/nkeys"
 	"github.com/nats-io/nuid"
 )
@@ -802,7 +801,7 @@ func (a *Account) AddWeightedMappings(src string, dests ...*MapDest) error {
 	m := &mapping{src: src, wc: subjectHasWildcard(src), dests: make([]*destination, 0, len(dests)+1)}
 	seen := make(map[string]struct{})
 
-	var tw = make(map[string]uint8)
+	tw := make(map[string]uint8)
 	for _, d := range dests {
 		if _, ok := seen[d.Subject]; ok {
 			return fmt.Errorf("duplicate entry for %q", d.Subject)
@@ -1006,7 +1005,7 @@ func (a *Account) selectMappedSubject(dest string) (string, bool) {
 	if len(dests) == 1 && dests[0].weight == 100 {
 		d = dests[0]
 	} else {
-		w := uint8(fastrand.Uint32n(100))
+		w := uint8(rand.Uint32N(100))
 		for _, rm := range dests {
 			if w < rm.weight {
 				d = rm
@@ -1217,7 +1216,8 @@ func (a *Account) AddServiceExportWithResponse(subject string, respType ServiceR
 
 // AddServiceExportWithresponse will configure the account with the defined export and response type.
 func (a *Account) addServiceExportWithResponseAndAccountPos(
-	subject string, respType ServiceRespType, accounts []*Account, accountPos uint) error {
+	subject string, respType ServiceRespType, accounts []*Account, accountPos uint,
+) error {
 	if a == nil {
 		return ErrMissingAccount
 	}
@@ -2388,7 +2388,7 @@ func shouldSample(l *serviceLatency, c *client) (bool, http.Header) {
 	if l.sampling >= 100 {
 		return true, nil
 	}
-	if l.sampling > 0 && rand.Int31n(100) <= int32(l.sampling) {
+	if l.sampling > 0 && rand.Int32N(100) <= int32(l.sampling) {
 		return true, nil
 	}
 	h := c.parseState.getHeader()
@@ -2480,8 +2480,8 @@ func (a *Account) processServiceImportResponse(sub *subscription, c *client, _ *
 // for all service replies, unless we are bound to a leafnode.
 // Lock should be held.
 func (a *Account) createRespWildcard() {
-	var b = [baseServerLen]byte{'_', 'R', '_', '.'}
-	rn := fastrand.Uint64()
+	b := [baseServerLen]byte{'_', 'R', '_', '.'}
+	rn := rand.Uint64()
 	for i, l := replyPrefixLen, rn; i < len(b); i++ {
 		b[i] = digits[l%base]
 		l /= base
@@ -2500,7 +2500,7 @@ func isTrackedReply(reply []byte) bool {
 func (a *Account) newServiceReply(tracking bool) []byte {
 	a.mu.Lock()
 	s := a.srv
-	rn := fastrand.Uint64()
+	rn := rand.Uint64()
 
 	// Check if we need to create the reply here.
 	var createdSiReply bool
@@ -3609,7 +3609,8 @@ func (s *Server) updateAccountClaimsWithRefresh(a *Account, ac *jwt.AccountClaim
 		case jwt.Stream:
 			s.Debugf("Adding stream export %q for %s", e.Subject, tl)
 			if err := a.addStreamExportWithAccountPos(
-				string(e.Subject), authAccounts(e.TokenReq), e.AccountTokenPosition); err != nil {
+				string(e.Subject), authAccounts(e.TokenReq), e.AccountTokenPosition,
+			); err != nil {
 				s.Debugf("Error adding stream export to account [%s]: %v", tl, err.Error())
 			}
 		case jwt.Service:
@@ -3622,7 +3623,8 @@ func (s *Server) updateAccountClaimsWithRefresh(a *Account, ac *jwt.AccountClaim
 				rt = Chunked
 			}
 			if err := a.addServiceExportWithResponseAndAccountPos(
-				string(e.Subject), rt, authAccounts(e.TokenReq), e.AccountTokenPosition); err != nil {
+				string(e.Subject), rt, authAccounts(e.TokenReq), e.AccountTokenPosition,
+			); err != nil {
 				s.Debugf("Error adding service export to account [%s]: %v", tl, err)
 				continue
 			}
@@ -4133,7 +4135,7 @@ func buildInternalNkeyUser(uc *jwt.UserClaims, acts map[string]struct{}, acc *Ac
 	}
 
 	// Now check for permissions.
-	var p = buildPermissionsFromJwt(&uc.Permissions)
+	p := buildPermissionsFromJwt(&uc.Permissions)
 	if p == nil {
 		nu.defaultPerms = true
 		acc.mu.RLock()

internal/fastrand/fastrand.go

@@ -24,7 +24,7 @@ import (
 	"fmt"
 	"io"
 	"math"
-	"math/rand"
+	"math/rand/v2"
 	"net"
 	"net/http"
 	"net/url"
@@ -39,7 +39,6 @@ import (
 
 	"github.com/klauspost/compress/s2"
 	"github.com/nats-io/jwt/v2"
-	"github.com/nats-io/nats-server/v2/internal/fastrand"
 )
 
 // Type of client connection.
@@ -229,6 +228,7 @@ const (
 
 // Some flags passed to processMsgResults
 const pmrNoFlag int = 0
+
 const (
 	pmrCollectQueueNames int = 1 << iota
 	pmrIgnoreEmptyQueueFilter
@@ -362,9 +362,11 @@ type outbound struct {
 
 const nbMaxVectorSize = 1024 // == IOV_MAX on Linux/Darwin and most other Unices (except Solaris/AIX)
 
-const nbPoolSizeSmall = 512   // Underlying array size of small buffer
-const nbPoolSizeMedium = 4096 // Underlying array size of medium buffer
-const nbPoolSizeLarge = 65536 // Underlying array size of large buffer
+const (
+	nbPoolSizeSmall  = 512   // Underlying array size of small buffer
+	nbPoolSizeMedium = 4096  // Underlying array size of medium buffer
+	nbPoolSizeLarge  = 65536 // Underlying array size of large buffer
+)
 
 var nbPoolSmall = &sync.Pool{
 	New: func() any {
@@ -703,8 +705,10 @@ type ClientOpts struct {
 	ProxySig string `json:"proxy_sig,omitempty"`
 }
 
-var defaultOpts = ClientOpts{Verbose: true, Pedantic: true, Echo: true}
-var internalOpts = ClientOpts{Verbose: false, Pedantic: false, Echo: false}
+var (
+	defaultOpts  = ClientOpts{Verbose: true, Pedantic: true, Echo: true}
+	internalOpts = ClientOpts{Verbose: false, Pedantic: false, Echo: false}
+)
 
 func (c *client) setTraceLevel() {
 	if c.kind == SYSTEM && !(atomic.LoadInt32(&c.srv.logging.traceSysAcc) != 0) {
@@ -720,7 +724,7 @@ func (c *client) initClient() {
 	c.cid = atomic.AddUint64(&s.gcid, 1)
 
 	// Outbound data structure setup
-	c.out.sg = sync.NewCond(&(c.mu))
+	c.out.sg = sync.NewCond(&c.mu)
 	opts := s.getOpts()
 	// Snapshots to avoid mutex access in fast paths.
 	c.out.wdl = opts.WriteDeadline
@@ -1691,7 +1695,7 @@ func (c *client) readLoop(pre []byte) {
 			return
 		}
 
-		if cpacc && (c.in.start.Sub(lpacc)) >= closedSubsCheckInterval {
+		if cpacc && c.in.start.Sub(lpacc) >= closedSubsCheckInterval {
 			c.pruneClosedSubFromPerAccountCache()
 			lpacc = time.Now()
 		}
@@ -5239,7 +5243,7 @@ func (c *client) processMsgResults(acc *Account, r *SublistResult, msg, deliver,
 	}
 
 	var rplyHasGWPrefix bool
-	var creply = reply
+	creply := reply
 
 	// If the reply subject is a GW routed reply, we will perform some
 	// tracking in deliverMsg(). We also want to send to the user the
@@ -5513,7 +5517,7 @@ func (c *client) processMsgResults(acc *Account, r *SublistResult, msg, deliver,
 						// We already have a LEAF and this is another one.
 						// Flip a coin to see if we swap it or not.
 						// See https://github.com/nats-io/nats-server/issues/6040
-						if fastrand.Uint32()%2 == 1 {
+						if rand.Uint32()%2 == 1 {
 							rsub = sub
 						}
 					}
@@ -5527,7 +5531,7 @@ func (c *client) processMsgResults(acc *Account, r *SublistResult, msg, deliver,
 		sindex := 0
 		lqs := len(qsubs)
 		if lqs > 1 {
-			sindex = int(fastrand.Uint32() % uint32(lqs))
+			sindex = int(rand.Uint32() % uint32(lqs))
 		}
 
 		// Find a subscription that is able to deliver this message starting at a random index.
@@ -6326,12 +6330,12 @@ func (c *client) clearAccountSubs(close bool) {
 		// Process any qsubs here.
 		for _, esub := range qsubs {
 			if !spoke {
-				srv.updateRouteSubscriptionMap(acc, esub.sub, -(esub.n))
+				srv.updateRouteSubscriptionMap(acc, esub.sub, -esub.n)
 				if srv.gateway.enabled {
-					srv.gatewayUpdateSubInterest(acc.Name, esub.sub, -(esub.n))
+					srv.gatewayUpdateSubInterest(acc.Name, esub.sub, -esub.n)
 				}
 			}
-			acc.updateLeafNodes(esub.sub, -(esub.n))
+			acc.updateLeafNodes(esub.sub, -esub.n)
 		}
 	}
 
@@ -7030,7 +7034,7 @@ func (c *client) setFirstPingTimer() {
 		}
 	}
 	// We randomize the first one by an offset up to 20%, e.g. 2m ~= max 24s.
-	addDelay := rand.Int63n(int64(d / 5))
+	addDelay := rand.Int64N(int64(d / 5))
 	d += time.Duration(addDelay)
 	// In the case of ROUTER/LEAF and when compression is configured, it is possible
 	// that this timer was already set, but just to detect a stale connection