Revert "p2p: use slices package for sorting (ethereum#27494)"

This reverts commit 9bcadfb.

p2p/discover/ntp.go

@@ -22,17 +22,25 @@ package discover
 import (
 	"fmt"
 	"net"
+	"sort"
 	"time"
 
 	"github.com/ethereum/go-ethereum/log"
-	"golang.org/x/exp/slices"
 )
 
 const (
 	ntpPool   = "pool.ntp.org" // ntpPool is the NTP server to query for the current time
 	ntpChecks = 3              // Number of measurements to do against the NTP server
 )
 
+// durationSlice attaches the methods of sort.Interface to []time.Duration,
+// sorting in increasing order.
+type durationSlice []time.Duration
+
+func (s durationSlice) Len() int           { return len(s) }
+func (s durationSlice) Less(i, j int) bool { return s[i] < s[j] }
+func (s durationSlice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+
 // checkClockDrift queries an NTP server for clock drifts and warns the user if
 // one large enough is detected.
 func checkClockDrift() {
@@ -101,7 +109,7 @@ func sntpDrift(measurements int) (time.Duration, error) {
 		drifts = append(drifts, sent.Sub(t)+elapsed/2)
 	}
 	// Calculate average drift (drop two extremities to avoid outliers)
-	slices.Sort(drifts)
+	sort.Sort(durationSlice(drifts))
 
 	drift := time.Duration(0)
 	for i := 1; i < len(drifts)-1; i++ {

p2p/discover/table_util_test.go

@@ -24,12 +24,12 @@ import (
 	"fmt"
 	"math/rand"
 	"net"
+	"sort"
 	"sync"
 
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
-	"golang.org/x/exp/slices"
 )
 
 var nullNode *enode.Node
@@ -217,14 +217,14 @@ func nodeEqual(n1 *enode.Node, n2 *enode.Node) bool {
 }
 
 func sortByID(nodes []*enode.Node) {
-	slices.SortFunc(nodes, func(a, b *enode.Node) bool {
-		return string(a.ID().Bytes()) < string(b.ID().Bytes())
+	sort.Slice(nodes, func(i, j int) bool {
+		return string(nodes[i].ID().Bytes()) < string(nodes[j].ID().Bytes())
 	})
 }
 
 func sortedByDistanceTo(distbase enode.ID, slice []*node) bool {
-	return slices.IsSortedFunc(slice, func(a, b *node) bool {
-		return enode.DistCmp(distbase, a.ID(), b.ID()) < 0
+	return sort.SliceIsSorted(slice, func(i, j int) bool {
+		return enode.DistCmp(distbase, slice[i].ID(), slice[j].ID()) < 0
 	})
 }
 

p2p/discover/v4_lookup_test.go

@@ -20,13 +20,13 @@ import (
 	"crypto/ecdsa"
 	"fmt"
 	"net"
+	"sort"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/p2p/discover/v4wire"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
-	"golang.org/x/exp/slices"
 )
 
 func TestUDPv4_Lookup(t *testing.T) {
@@ -302,8 +302,8 @@ func (tn *preminedTestnet) closest(n int) (nodes []*enode.Node) {
 			nodes = append(nodes, tn.node(d, i))
 		}
 	}
-	slices.SortFunc(nodes, func(a, b *enode.Node) bool {
-		return enode.DistCmp(tn.target.id(), a.ID(), b.ID()) < 0
+	sort.Slice(nodes, func(i, j int) bool {
+		return enode.DistCmp(tn.target.id(), nodes[i].ID(), nodes[j].ID()) < 0
 	})
 	return nodes[:n]
 }

p2p/discover/v5_udp_test.go

@@ -24,6 +24,7 @@ import (
 	"math/rand"
 	"net"
 	"reflect"
+	"sort"
 	"testing"
 	"time"
 
@@ -34,7 +35,6 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/enr"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/stretchr/testify/require"
-	"golang.org/x/exp/slices"
 )
 
 // Real sockets, real crypto: this test checks end-to-end connectivity for UDPv5.
@@ -61,8 +61,8 @@ func TestUDPv5_lookupE2E(t *testing.T) {
 	for i := range nodes {
 		expectedResult[i] = nodes[i].Self()
 	}
-	slices.SortFunc(expectedResult, func(a, b *enode.Node) bool {
-		return enode.DistCmp(target.ID(), a.ID(), b.ID()) < 0
+	sort.Slice(expectedResult, func(i, j int) bool {
+		return enode.DistCmp(target.ID(), expectedResult[i].ID(), expectedResult[j].ID()) < 0
 	})
 
 	// Do the lookup.

p2p/dnsdisc/tree.go

@@ -23,14 +23,14 @@ import (
 	"encoding/base64"
 	"fmt"
 	"io"
+	"sort"
 	"strings"
 
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
 	"github.com/ethereum/go-ethereum/rlp"
 	"golang.org/x/crypto/sha3"
-	"golang.org/x/exp/slices"
 )
 
 // Tree is a merkle tree of node records.
@@ -214,8 +214,8 @@ func (t *Tree) build(entries []entry) entry {
 }
 
 func sortByID(nodes []*enode.Node) []*enode.Node {
-	slices.SortFunc(nodes, func(a, b *enode.Node) bool {
-		return bytes.Compare(a.ID().Bytes(), b.ID().Bytes()) < 0
+	sort.Slice(nodes, func(i, j int) bool {
+		return bytes.Compare(nodes[i].ID().Bytes(), nodes[j].ID().Bytes()) < 0
 	})
 	return nodes
 }

p2p/peer.go

@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"sort"
 	"sync"
 	"time"
 
@@ -31,7 +32,6 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
 	"github.com/ethereum/go-ethereum/rlp"
-	"golang.org/x/exp/slices"
 )
 
 var (
@@ -375,7 +375,7 @@ func countMatchingProtocols(protocols []Protocol, caps []Cap) int {
 
 // matchProtocols creates structures for matching named subprotocols.
 func matchProtocols(protocols []Protocol, caps []Cap, rw MsgReadWriter) map[string]*protoRW {
-	slices.SortFunc(caps, Cap.Less)
+	sort.Sort(capsByNameAndVersion(caps))
 	offset := baseProtocolLength
 	result := make(map[string]*protoRW)
 

p2p/protocol.go

@@ -77,10 +77,10 @@ func (cap Cap) String() string {
 	return fmt.Sprintf("%s/%d", cap.Name, cap.Version)
 }
 
-// Less defines the canonical sorting order of capabilities.
-func (cap Cap) Less(other Cap) bool {
-	if cap.Name == other.Name {
-		return cap.Version < other.Version
-	}
-	return cap.Name < other.Name
+type capsByNameAndVersion []Cap
+
+func (cs capsByNameAndVersion) Len() int      { return len(cs) }
+func (cs capsByNameAndVersion) Swap(i, j int) { cs[i], cs[j] = cs[j], cs[i] }
+func (cs capsByNameAndVersion) Less(i, j int) bool {
+	return cs[i].Name < cs[j].Name || (cs[i].Name == cs[j].Name && cs[i].Version < cs[j].Version)
 }

p2p/server.go

@@ -24,6 +24,7 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"sort"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -38,7 +39,6 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/enr"
 	"github.com/ethereum/go-ethereum/p2p/nat"
 	"github.com/ethereum/go-ethereum/p2p/netutil"
-	"golang.org/x/exp/slices"
 )
 
 const (
@@ -498,7 +498,7 @@ func (srv *Server) setupLocalNode() error {
 	for _, p := range srv.Protocols {
 		srv.ourHandshake.Caps = append(srv.ourHandshake.Caps, p.cap())
 	}
-	slices.SortFunc(srv.ourHandshake.Caps, Cap.Less)
+	sort.Sort(capsByNameAndVersion(srv.ourHandshake.Caps))
 
 	// Create the local node.
 	db, err := enode.OpenDB(srv.NodeDatabase)