Merge pull request #255 from ydb-platform/grow_struct_slice

enhance struct value construction

Author: asmyasnikov

CHANGELOG.md

@@ -1,3 +1,5 @@
+* Refactor Struct value creation
+
 ## v3.25.2
 * Fixed repeater initial force timeout from 500 to 0.5 second
 
@@ -14,7 +16,7 @@
 * Enabled by default keep-in-cache policy for data queries
 * Removed from `ydb.Connection` embedding of `grpc.ClientConnInterface`
 * Fixed stopping of repeater
-* Added log backoff between force repeater wake up's (from 500ms to 32s) 
+* Added log backoff between force repeater wake up's (from 500ms to 32s)
 * Renamed `trace.DriverRepeaterTick{Start,Done}Info` to `trace.DriverRepeaterWakeUp{Start,Done}Info`
 * Fixed unexpected `NullFlag` while parse nil `JSONDocument` value
 * Removed `internal/conn/conn.streamUsages` and `internal/conn/conn.usages` (`internal/conn.conn` always touching last usage timestamp on API calls)
@@ -35,15 +37,15 @@
 * Fixed re-opening case after close lazy-initialized clients
 * Removed dependency of call context for initializing lazy table client
 * Added `config.AutoRetry()` flag with `true` value by default. `config.AutoRetry()` affects how to errors handle in sub-clients calls.
-* Added `config.WithNoAutoRetry` for disabling auto-retry on errors in sub-clients calls 
+* Added `config.WithNoAutoRetry` for disabling auto-retry on errors in sub-clients calls
 * Refactored `internal/lazy` package (supported check `config.AutoRetry()`, removed all error wrappings with stacktrace)
 
 ## v3.23.0
 * Added `WithTLSConfig` option for redefine TLS config
 * Added `sugar.LoadCertificatesFromFile` and `sugar.LoadCertificatesFromPem` helpers
 
 ## v3.22.0
-* Supported `json.Unmarshaler` type for scanning row to values 
+* Supported `json.Unmarshaler` type for scanning row to values
 * Reimplemented `sugar.DSN` with `net/url`
 
 ## v3.21.0

internal/value/value.go

@@ -502,6 +502,19 @@ type StructValueProto struct {
 	Values []*Ydb.Value
 }
 
+func (s *StructValueProto) Grow(size int) {
+	if cap(s.Fields) < size {
+		newFields := make([]StructField, 0, size)
+		newFields = append(newFields, s.Fields...)
+		s.Fields = newFields
+	}
+	if cap(s.Values) < size {
+		newValues := make([]*Ydb.Value, 0, size)
+		newValues = append(newValues, s.Values...)
+		s.Values = newValues
+	}
+}
+
 func (s *StructValueProto) Add(name string, value V) {
 	s.Fields = append(s.Fields, StructField{
 		Name: name,

table/types/value.go

@@ -147,18 +147,28 @@ func ListValue(vs ...Value) Value {
 
 type tStructValueProto value.StructValueProto
 
-type StructValueOption func(*tStructValueProto)
+type StructValueOption interface {
+	apply(*tStructValueProto)
+}
+
+type structField struct {
+	name  string
+	value Value
+}
+
+func (f structField) apply(p *tStructValueProto) {
+	(*value.StructValueProto)(p).Add(f.name, f.value)
+}
 
 func StructFieldValue(name string, v Value) StructValueOption {
-	return func(p *tStructValueProto) {
-		(*value.StructValueProto)(p).Add(name, v)
-	}
+	return structField{name: name, value: v}
 }
 
 func StructValue(opts ...StructValueOption) Value {
 	var p tStructValueProto
+	(*value.StructValueProto)(&p).Grow(len(opts))
 	for _, opt := range opts {
-		opt(&p)
+		opt.apply(&p)
 	}
 	return value.StructValue((*value.StructValueProto)(&p))
 }