incorporate suggestions

spanner/client.go

@@ -28,7 +28,6 @@ import (
 	"cloud.google.com/go/internal/trace"
 	sppb "cloud.google.com/go/spanner/apiv1/spannerpb"
 	"github.com/googleapis/gax-go/v2"
-	jsoniter "github.com/json-iterator/go"
 	"google.golang.org/api/iterator"
 	"google.golang.org/api/option"
 	"google.golang.org/api/option/internaloption"
@@ -187,10 +186,6 @@ type ClientConfig struct {
 
 	// BatchTimeout specifies the timeout for a batch of sessions managed sessionClient.
 	BatchTimeout time.Duration
-
-	// UseNumber causes the Decoder to unmarshal a number into an interface{} as a
-	// Number instead of as a float64.
-	UseNumber bool
 }
 
 func contextWithOutgoingMetadata(ctx context.Context, md metadata.MD, disableRouteToLeader bool) context.Context {
@@ -270,14 +265,7 @@ func NewClientWithConfig(ctx context.Context, database string, config ClientConf
 	if config.BatchTimeout == 0 {
 		config.BatchTimeout = time.Minute
 	}
-	once.Do(func() {
-		// Initialize json provider.
-		jsonProvider = jsoniter.Config{
-			EscapeHTML:  true,
-			SortMapKeys: true, // Sort map keys to ensure deterministic output, to be consistent with encoding.
-			UseNumber:   config.UseNumber,
-		}.Froze()
-	})
+
 	md := metadata.Pairs(resourcePrefixHeader, database)
 	if config.Compression == gzip.Name {
 		md.Append(requestsCompressionHeader, gzip.Name)

spanner/integration_test.go

@@ -2000,6 +2000,8 @@ func TestIntegration_BasicTypes(t *testing.T) {
 					JSONArray	ARRAY<JSON>
 				) PRIMARY KEY (RowID)`,
 	}
+	client, _, cleanup := prepareIntegrationTest(ctx, t, DefaultSessionPoolConfig, stmts)
+	defer cleanup()
 
 	t1, _ := time.Parse(time.RFC3339Nano, "2016-11-15T15:04:05.999999999Z")
 	// Boundaries
@@ -2167,20 +2169,10 @@ func TestIntegration_BasicTypes(t *testing.T) {
 		}...)
 	}
 
-	var dbPath string
 	for idx := 0; idx < 2; idx++ {
-		var c *Client
-		if idx == 0 {
-			var cleanup func()
-			c, dbPath, cleanup = prepareIntegrationTest(ctx, t, DefaultSessionPoolConfig, stmts)
-			defer cleanup()
-		} else {
-			var err error
-			c, err = createClient(ctx, dbPath, ClientConfig{UseNumber: true, SessionPoolConfig: DefaultSessionPoolConfig})
-			require.NoError(t, err)
-			defer c.Close()
-			enableJSONProviderNumberConfig(true)
-			defer enableJSONProviderNumberConfig(false)
+		if idx == 1 {
+			UseNumberWithJSONDecoderEncoder()
+			defer testSetJSONProviderNumberConfig(false)
 		}
 		// Write rows into table first using DML.
 		statements := make([]Statement, 0)
@@ -2192,7 +2184,7 @@ func TestIntegration_BasicTypes(t *testing.T) {
 			stmt.Params["value"] = test.val
 			statements = append(statements, stmt)
 		}
-		_, err := c.ReadWriteTransaction(ctx, func(ctx context.Context, tx *ReadWriteTransaction) error {
+		_, err := client.ReadWriteTransaction(ctx, func(ctx context.Context, tx *ReadWriteTransaction) error {
 			rowCounts, err := tx.BatchUpdate(ctx, statements)
 			if err != nil {
 				return err
@@ -2211,7 +2203,7 @@ func TestIntegration_BasicTypes(t *testing.T) {
 			t.Fatalf("failed to insert values using DML: %v", err)
 		}
 		// Delete all the rows so we can insert them using mutations as well.
-		_, err = c.Apply(ctx, []*Mutation{Delete("Types", AllKeys())})
+		_, err = client.Apply(ctx, []*Mutation{Delete("Types", AllKeys())})
 		if err != nil {
 			t.Fatalf("failed to delete all rows: %v", err)
 		}
@@ -2221,12 +2213,12 @@ func TestIntegration_BasicTypes(t *testing.T) {
 		for i, test := range tests {
 			muts = append(muts, InsertOrUpdate("Types", []string{"RowID", test.col}, []interface{}{i, test.val}))
 		}
-		if _, err := c.Apply(ctx, muts, ApplyAtLeastOnce()); err != nil {
+		if _, err := client.Apply(ctx, muts, ApplyAtLeastOnce()); err != nil {
 			t.Fatal(err)
 		}
 
 		for i, test := range tests {
-			row, err := c.Single().ReadRow(ctx, "Types", []interface{}{i}, []string{test.col})
+			row, err := client.Single().ReadRow(ctx, "Types", []interface{}{i}, []string{test.col})
 			if err != nil {
 				t.Fatalf("Unable to fetch row %v: %v", i, err)
 			}
@@ -2258,10 +2250,9 @@ func TestIntegration_BasicTypes(t *testing.T) {
 			}
 		}
 		// cleanup
-		_, err = c.Apply(ctx, []*Mutation{Delete("Types", AllKeys())})
+		_, err = client.Apply(ctx, []*Mutation{Delete("Types", AllKeys())})
 		require.NoError(t, err)
 	}
-
 }
 
 // Test decoding Cloud Spanner STRUCT type.
@@ -5549,7 +5540,7 @@ func checkCommonTagsGFELatency(t *testing.T, m map[tag.Key]string) {
 }
 
 // helper method to enable json provider with useNumber flag, only for testing.
-func enableJSONProviderNumberConfig(useNumber bool) {
+func testSetJSONProviderNumberConfig(useNumber bool) {
 	jsonProvider = jsoniter.Config{
 		EscapeHTML:  true,
 		SortMapKeys: true, // Sort map keys to ensure deterministic output, to be consistent with encoding.

spanner/value.go

@@ -28,9 +28,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
-	"sync/atomic"
 	"time"
-	"unsafe"
 
 	"cloud.google.com/go/civil"
 	"cloud.google.com/go/internal/fields"
@@ -117,21 +115,22 @@ var (
 
 	jsonNullBytes = []byte("null")
 
-	jsonProvider jsoniter.API
+	jsonProvider = jsoniter.ConfigCompatibleWithStandardLibrary
 
 	once sync.Once
 )
 
-// UseNumber specifies whether number values inside a Cloud Spanner JSON value
-// should be decoded as a Number or a float64.
-// Decoding to a Number guarantees that the precision used by Cloud Spanner is preserved.
-// Decoding to a float64 can cause loss of precision.
-// The default JSON decode function in Go uses float64, This is therefore also the default used by this client library.
-// Change this value to true to prevent loss of precision.
+// UseNumberWithJSONDecoderEncoder specifies whether Cloud Spanner JSON numbers are decoded
+// as Number (preserving precision) or float64 (risking loss).
+// Defaults to float64, call this method for lossless precision.
+// NOTE: This change affects all clients created by this library, both existing and future ones.
 func UseNumberWithJSONDecoderEncoder() {
-	atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&jsonProvider)))
 	once.Do(func() {
-		jsonProvider = jsoniter.ConfigCompatibleWithStandardLibrary
+		jsonProvider = jsoniter.Config{
+			EscapeHTML:  true,
+			SortMapKeys: true, // Sort map keys to ensure deterministic output, to be consistent with encoding.
+			UseNumber:   true,
+		}.Froze()
 	})
 }