GODRIVER-2689 (POC) Simplify the "readpref" API

event/description.go

@@ -11,7 +11,7 @@ import (
 
 	"go.mongodb.org/mongo-driver/v2/bson"
 	"go.mongodb.org/mongo-driver/v2/mongo/address"
-	"go.mongodb.org/mongo-driver/v2/tag"
+	"go.mongodb.org/mongo-driver/v2/mongo/readpref"
 )
 
 // ServerDescription contains information about a node in a cluster. This is
@@ -43,7 +43,7 @@ type ServerDescription struct {
 	SessionTimeoutMinutes    *int64
 	SetName                  string
 	SetVersion               uint32
-	Tags                     tag.Set
+	Tags                     readpref.TagSet
 	TopologyVersionProcessID bson.ObjectID
 	TopologyVersionCounter   int64
 }

internal/driverutil/description.go

@@ -16,7 +16,7 @@ import (
 	"go.mongodb.org/mongo-driver/v2/internal/handshake"
 	"go.mongodb.org/mongo-driver/v2/internal/ptrutil"
 	"go.mongodb.org/mongo-driver/v2/mongo/address"
-	"go.mongodb.org/mongo-driver/v2/tag"
+	"go.mongodb.org/mongo-driver/v2/mongo/readpref"
 	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/description"
 )
 
@@ -421,7 +421,7 @@ func NewServerDescription(addr address.Address, response bson.Raw) description.S
 				desc.LastError = err
 				return desc
 			}
-			desc.Tags = tag.NewTagSetFromMap(m)
+			desc.Tags = readpref.NewTagSetFromMap(m)
 		case "topologyVersion":
 			doc, ok := element.Value().DocumentOK()
 			if !ok {

internal/integration/database_test.go

@@ -75,7 +75,7 @@ func TestDatabase(t *testing.T) {
 			// layer, which should add a top-level $readPreference field to the command.
 
 			runCmdOpts := options.RunCmd().
-				SetReadPreference(readpref.SecondaryPreferred())
+				SetReadPreference(&readpref.ReadPref{Mode: readpref.SecondaryPreferredMode})
 			err := mt.DB.RunCommand(context.Background(), bson.D{{handshake.LegacyHello, 1}}, runCmdOpts).Err()
 			assert.Nil(mt, err, "RunCommand error: %v", err)
 

internal/integration/initial_dns_seedlist_discovery_test.go

@@ -87,7 +87,7 @@ func runSeedlistDiscoveryPingTest(mt *mtest.T, clientOpts *options.ClientOptions
 	defer cancel()
 
 	// Ping the server.
-	err = client.Ping(pingCtx, readpref.Nearest())
+	err = client.Ping(pingCtx, &readpref.ReadPref{Mode: readpref.NearestMode})
 	assert.Nil(mt, err, "Ping error: %v", err)
 }
 

internal/integration/json_helpers_test.go

@@ -420,13 +420,13 @@ func readPrefFromString(s string) *readpref.ReadPref {
 	case "primary":
 		return readpref.Primary()
 	case "primarypreferred":
-		return readpref.PrimaryPreferred()
+		return &readpref.ReadPref{Mode: readpref.PrimaryPreferredMode}
 	case "secondary":
-		return readpref.Secondary()
+		return &readpref.ReadPref{Mode: readpref.SecondaryMode}
 	case "secondarypreferred":
-		return readpref.SecondaryPreferred()
+		return &readpref.ReadPref{Mode: readpref.SecondaryPreferredMode}
 	case "nearest":
-		return readpref.Nearest()
+		return &readpref.ReadPref{Mode: readpref.NearestMode}
 	}
 	return readpref.Primary()
 }

internal/integration/mtest/mongotest.go

@@ -36,7 +36,7 @@ var (
 	// PrimaryRp is the primary read preference.
 	PrimaryRp = readpref.Primary()
 	// SecondaryRp is the secondary read preference.
-	SecondaryRp = readpref.Secondary()
+	SecondaryRp = &readpref.ReadPref{Mode: readpref.SecondaryMode}
 	// LocalRc is the local read concern
 	LocalRc = readconcern.Local()
 	// MajorityRc is the majority read concern

internal/integration/unified/common_options.go

@@ -14,7 +14,6 @@ import (
 	"go.mongodb.org/mongo-driver/v2/mongo/readconcern"
 	"go.mongodb.org/mongo-driver/v2/mongo/readpref"
 	"go.mongodb.org/mongo-driver/v2/mongo/writeconcern"
-	"go.mongodb.org/mongo-driver/v2/tag"
 )
 
 // This file defines helper types to convert BSON documents to ReadConcern, WriteConcern, and ReadPref objects.
@@ -70,32 +69,34 @@ func (rp *ReadPreference) ToReadPrefOption() (*readpref.ReadPref, error) {
 		return nil, fmt.Errorf("invalid read preference mode %q", rp.Mode)
 	}
 
-	var rpOptions []readpref.Option
+	rpOpts := readpref.Options()
+
 	if rp.TagSets != nil {
 		// Each item in the TagSets slice is a document that represents one set.
-		sets := make([]tag.Set, 0, len(rp.TagSets))
+		sets := make([]readpref.TagSet, 0, len(rp.TagSets))
 		for _, rawSet := range rp.TagSets {
-			parsed := make(tag.Set, 0, len(rawSet))
+			parsed := make(readpref.TagSet, 0, len(rawSet))
 			for k, v := range rawSet {
-				parsed = append(parsed, tag.Tag{Name: k, Value: v})
+				parsed = append(parsed, readpref.Tag{Name: k, Value: v})
 			}
 			sets = append(sets, parsed)
 		}
 
-		rpOptions = append(rpOptions, readpref.WithTagSets(sets...))
+		rpOpts.SetTagSets(sets)
 	}
 	if rp.MaxStalenessSeconds != nil {
 		maxStaleness := time.Duration(*rp.MaxStalenessSeconds) * time.Second
-		rpOptions = append(rpOptions, readpref.WithMaxStaleness(maxStaleness))
+		rpOpts.SetMaxStaleness(maxStaleness)
 	}
 	if rp.Hedge != nil {
 		if len(rp.Hedge) > 1 {
 			return nil, fmt.Errorf("invalid read preference hedge document: length cannot be greater than 1")
 		}
 		if enabled, ok := rp.Hedge["enabled"]; ok {
-			rpOptions = append(rpOptions, readpref.WithHedgeEnabled(enabled.(bool)))
+			hedgeEnabled := enabled.(bool)
+			rpOpts.SetHedgeEnabled(hedgeEnabled)
 		}
 	}
 
-	return readpref.New(mode, rpOptions...)
+	return readpref.New(mode, rpOpts)
 }

internal/serverselector/server_selector.go

@@ -12,7 +12,6 @@ import (
 	"time"
 
 	"go.mongodb.org/mongo-driver/v2/mongo/readpref"
-	"go.mongodb.org/mongo-driver/v2/tag"
 	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/description"
 )
 
@@ -190,12 +189,12 @@ func (ssf Func) SelectServer(
 }
 
 func verifyMaxStaleness(rp *readpref.ReadPref, topo description.Topology) error {
-	maxStaleness, set := rp.MaxStaleness()
-	if !set {
+	maxStaleness := rp.MaxStaleness()
+	if maxStaleness == nil {
 		return nil
 	}
 
-	if maxStaleness < 90*time.Second {
+	if *maxStaleness < 90*time.Second {
 		return fmt.Errorf("max staleness (%s) must be greater than or equal to 90s", maxStaleness)
 	}
 
@@ -208,7 +207,7 @@ func verifyMaxStaleness(rp *readpref.ReadPref, topo description.Topology) error
 	s := topo.Servers[0]
 	idleWritePeriod := 10 * time.Second
 
-	if maxStaleness < s.HeartbeatInterval+idleWritePeriod {
+	if *maxStaleness < s.HeartbeatInterval+idleWritePeriod {
 		return fmt.Errorf(
 			"max staleness (%s) must be greater than or equal to the heartbeat interval (%s) plus idle write period (%s)",
 			maxStaleness, s.HeartbeatInterval, idleWritePeriod,
@@ -242,7 +241,7 @@ func selectSecondaries(rp *readpref.ReadPref, candidates []description.Server) [
 	if len(secondaries) == 0 {
 		return secondaries
 	}
-	if maxStaleness, set := rp.MaxStaleness(); set {
+	if maxStaleness := rp.MaxStaleness(); maxStaleness != nil {
 		primaries := selectByKind(candidates, description.ServerKindRSPrimary)
 		if len(primaries) == 0 {
 			baseTime := secondaries[0].LastWriteTime
@@ -255,7 +254,7 @@ func selectSecondaries(rp *readpref.ReadPref, candidates []description.Server) [
 			var selected []description.Server
 			for _, secondary := range secondaries {
 				estimatedStaleness := baseTime.Sub(secondary.LastWriteTime) + secondary.HeartbeatInterval
-				if estimatedStaleness <= maxStaleness {
+				if estimatedStaleness <= *maxStaleness {
 					selected = append(selected, secondary)
 				}
 			}
@@ -269,7 +268,7 @@ func selectSecondaries(rp *readpref.ReadPref, candidates []description.Server) [
 		for _, secondary := range secondaries {
 			estimatedStaleness := secondary.LastUpdateTime.Sub(secondary.LastWriteTime) -
 				primary.LastUpdateTime.Sub(primary.LastWriteTime) + secondary.HeartbeatInterval
-			if estimatedStaleness <= maxStaleness {
+			if estimatedStaleness <= *maxStaleness {
 				selected = append(selected, secondary)
 			}
 		}
@@ -279,7 +278,7 @@ func selectSecondaries(rp *readpref.ReadPref, candidates []description.Server) [
 	return secondaries
 }
 
-func selectByTagSet(candidates []description.Server, tagSets []tag.Set) []description.Server {
+func selectByTagSet(candidates []description.Server, tagSets []readpref.TagSet) []description.Server {
 	if len(tagSets) == 0 {
 		return candidates
 	}
@@ -327,7 +326,7 @@ func selectForReplicaSet(
 		}
 	}
 
-	switch rp.Mode() {
+	switch rp.Mode {
 	case readpref.PrimaryMode:
 		return selectByKind(candidates, description.ServerKindRSPrimary), nil
 	case readpref.PrimaryPreferredMode:
@@ -355,5 +354,5 @@ func selectForReplicaSet(
 		return selectByTagSet(selected, rp.TagSets()), nil
 	}
 
-	return nil, fmt.Errorf("unsupported mode: %d", rp.Mode())
+	return nil, fmt.Errorf("unsupported mode: %d", rp.Mode)
 }