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Merged
chaokunyang merged 3 commits into from
Apr 14, 2026
Merged

perf(dart): optimize struct deserialize with direct dispatch codegen #3563

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19d097b
perf(dart): optimize struct deserialize with direct dispatch codegen
yash-agarwa-l Apr 14, 2026
629945d
Merge branch 'main' into struct_perf
chaokunyang Apr 14, 2026
5c197cf
Merge branch 'main' into struct_perf
chaokunyang Apr 14, 2026
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2 changes: 1 addition & 1 deletion benchmarks/dart/lib/src/workloads.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -158,7 +158,7 @@ buildBenchmarkDefinitions() {
}

Fory newBenchmarkFory() {
final fory = Fory(config: const Config(compatible: true));
final fory = Fory(compatible: true);
registerBenchmarkTypes(fory);
return fory;
}
90 changes: 71 additions & 19 deletions dart/packages/fory/lib/src/codegen/fory_generator.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -501,6 +501,14 @@ final class ForyGenerator extends Generator {
output.writeln(
' value.${field.name} = ${_directGeneratedTypedContainerReadExpression(structSpec.name, field, 'fields[$index]')};',
);
} else if (_usesDirectGeneratedStructFieldFastPath(field)) {
output.writeln(
' value.${field.name} = $readerFunctionName(readGeneratedStructDirectValue(context, fields[$index]), value.${field.name});',
);
} else if (_usesDirectGeneratedDeclaredReadFastPath(field)) {
output.writeln(
' value.${field.name} = $readerFunctionName(readGeneratedStructDeclaredValue(context, fields[$index]), value.${field.name});',
);
} else {
output.writeln(
' value.${field.name} = $readerFunctionName(readGeneratedStructFieldInfoValue(context, fields[$index], value.${field.name}), value.${field.name});',
Expand Down Expand Up @@ -531,12 +539,6 @@ final class ForyGenerator extends Generator {
output.writeln(' return value;');
case _ConstructorMode.constructor:
output.writeln(' final slots = generatedStructReadSlots(context);');
for (var index = 0; index < structSpec.fields.length; index += 1) {
final field = structSpec.fields[index];
output.writeln(
' late final ${field.displayType} ${field.localName};',
);
}
output.writeln(' if (slots == null) {');
if (hasDirectPrimitiveFastPath || directCursorRuns.isNotEmpty) {
output.writeln(' final buffer = context.buffer;');
Expand All @@ -555,48 +557,73 @@ final class ForyGenerator extends Generator {
}
if (_usesReservedGeneratedFastPath(field)) {
output.writeln(
' ${field.localName} = ${_directGeneratedCursorReadExpression(field, 'cursor${directCursorStartByIndex[index]}')};',
' final ${field.displayType} ${field.localName} = ${_directGeneratedCursorReadExpression(field, 'cursor${directCursorStartByIndex[index]}')};',
);
} else if (_usesDirectGeneratedBasicFastPath(field)) {
output.writeln(
' ${field.localName} = ${_directGeneratedReadExpression(field)};',
' final ${field.displayType} ${field.localName} = ${_directGeneratedReadExpression(field)};',
);
} else if (_usesDirectGeneratedTypedContainerReadFastPath(field)) {
output.writeln(
' ${field.localName} = ${_directGeneratedTypedContainerReadExpression(structSpec.name, field, 'fields[$index]')};',
' final ${field.displayType} ${field.localName} = ${_directGeneratedTypedContainerReadExpression(structSpec.name, field, 'fields[$index]')};',
);
} else if (_usesDirectGeneratedStructFieldFastPath(field)) {
output.writeln(
' final ${field.displayType} ${field.localName} = $readerFunctionName(readGeneratedStructDirectValue(context, fields[$index]));',
);
} else if (_usesDirectGeneratedDeclaredReadFastPath(field)) {
output.writeln(
' final ${field.displayType} ${field.localName} = $readerFunctionName(readGeneratedStructDeclaredValue(context, fields[$index]));',
);
} else {
output.writeln(
' ${field.localName} = $readerFunctionName(readGeneratedStructFieldInfoValue(context, fields[$index]));',
' final ${field.displayType} ${field.localName} = $readerFunctionName(readGeneratedStructFieldInfoValue(context, fields[$index]));',
);
}
final directCursorEndRun = directCursorRunByEnd[index];
if (directCursorEndRun != null) {
output.writeln(' cursor${directCursorEndRun.start}.finish();');
}
}
output.writeln(' } else {');
final constructorInvocation = _constructorInvocation(structSpec);
output
..writeln(' final value = $constructorInvocation;')
..writeln(' context.reference(value);');
for (final fieldName
in structSpec.constructorPlan.postConstructionFieldNames) {
final field =
structSpec.fields.firstWhere((item) => item.name == fieldName);
output.writeln(' value.${field.name} = ${field.localName};');
}
output.writeln(' return value;');
// Slow path: schema-evolution slots present. Use `late final` so each
// field can be conditionally assigned from its slot or read fresh.
output.writeln(' }');
for (var index = 0; index < structSpec.fields.length; index += 1) {
final field = structSpec.fields[index];
output.writeln(
' late final ${field.displayType} ${field.localName};',
);
}
for (var index = 0; index < structSpec.fields.length; index += 1) {
final field = structSpec.fields[index];
final readerFunctionName = field.readerFunctionName(structSpec.name);
final rawValueName = 'raw${structSpec.name}$index';
output.writeln(
' if (slots.containsSlot($index)) {',
' if (slots.containsSlot($index)) {',
);
output.writeln(
' final $rawValueName = slots.valueForSlot($index);',
' final $rawValueName = slots.valueForSlot($index);',
);
output.writeln(
' ${field.localName} = $readerFunctionName(${_slotResolvedRawExpression(rawValueName)});',
' ${field.localName} = $readerFunctionName(${_slotResolvedRawExpression(rawValueName)});',
);
output.writeln(' } else {');
output.writeln(' } else {');
output.writeln(
' ${field.localName} = $readerFunctionName(null);',
' ${field.localName} = $readerFunctionName(null);',
);
output.writeln(' }');
output.writeln(' }');
}
output.writeln(' }');
final constructorInvocation = _constructorInvocation(structSpec);
output
..writeln(' final value = $constructorInvocation;')
..writeln(' context.reference(value);');
Expand Down Expand Up @@ -939,6 +966,31 @@ GeneratedFieldType(
field.fieldType.typeId == TypeIds.enumById;
}

bool _usesDirectGeneratedDeclaredReadFastPath(
_GeneratedFieldSpec field,
) {
if (field.fieldType.nullable ||
field.fieldType.ref ||
field.fieldType.dynamic == true) {
return false;
}
final typeId = field.fieldType.typeId;
return typeId == TypeIds.ext || typeId == TypeIds.namedExt;
}

bool _usesDirectGeneratedStructFieldFastPath(_GeneratedFieldSpec field) {
if (field.fieldType.nullable ||
field.fieldType.ref ||
field.fieldType.dynamic == true) {
return false;
}
final typeId = field.fieldType.typeId;
return typeId == TypeIds.struct ||
typeId == TypeIds.compatibleStruct ||
typeId == TypeIds.namedStruct ||
typeId == TypeIds.namedCompatibleStruct;
}

bool _usesDirectGeneratedTypedContainerReadFastPath(
_GeneratedFieldSpec field,
) {
Expand Down
42 changes: 36 additions & 6 deletions dart/packages/fory/lib/src/codegen/generated_support.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -559,16 +559,12 @@ void registerGeneratedStruct<T>(

@internal
StructWriteSlots? generatedStructWriteSlots(WriteContext context) {
return context.getContextObject<StructWriteSlots>(
structWriteSlotsKey,
);
return context.structWriteSlots;
}

@internal
StructReadSlots? generatedStructReadSlots(ReadContext context) {
return context.getContextObject<StructReadSlots>(
structReadSlotsKey,
);
return context.structReadSlots;
}

@internal
Expand Down Expand Up @@ -687,6 +683,40 @@ Object? readGeneratedStructFieldInfoValue(
return readFieldValue(context, field, fallback);
}

@internal
Object? readGeneratedStructDeclaredValue(
ReadContext context,
GeneratedStructFieldInfo field,
) {
final resolved = fieldDeclaredTypeInfo(context.typeResolver, field)!;
if (fieldUsesDeclaredType(context.typeResolver, field)) {
return context.readResolvedValue(resolved, field.fieldType);
}
final actualResolved = context.readTypeMetaValue(
resolved.isNamed ? resolved : null,
);
return context.readResolvedValue(actualResolved, field.fieldType);
}

@internal
Object readGeneratedStructDirectValue(
ReadContext context,
GeneratedStructFieldInfo field,
) {
final declared = fieldDeclaredTypeInfo(context.typeResolver, field)!;
final resolver.TypeInfo resolved;
if (fieldUsesDeclaredType(context.typeResolver, field)) {
resolved = declared;
} else {
resolved =
context.readTypeMetaValue(declared.isNamed ? declared : null);
}
context.increaseDepth();
final value = resolved.structSerializer!.readValue(context, resolved);
context.decreaseDepth();
return value;
}

@internal
List<T> readGeneratedDirectListValue<T>(
ReadContext context,
Expand Down
33 changes: 6 additions & 27 deletions dart/packages/fory/lib/src/context/read_context.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,7 @@ import 'package:fory/src/serializer/map_serializers.dart';
import 'package:fory/src/serializer/primitive_serializers.dart';
import 'package:fory/src/serializer/scalar_serializers.dart';
import 'package:fory/src/serializer/serializer.dart';
import 'package:fory/src/serializer/struct_slots.dart';
import 'package:fory/src/serializer/typed_array_serializers.dart';
import 'package:fory/src/types/float16.dart';

Expand All @@ -29,7 +30,7 @@ final class ReadContext {

late Buffer _buffer;
final List<TypeInfo> _sharedTypes = <TypeInfo>[];
final Map<Object, Object?> _contextObjects = <Object, Object?>{};
StructReadSlots? _structReadSlots;
int _depth = 0;

@internal
Expand All @@ -50,7 +51,7 @@ final class ReadContext {
_sharedTypes.clear();
_refReader.reset();
_metaStringReader.reset();
_contextObjects.clear();
_structReadSlots = null;
_depth = 0;
}

Expand All @@ -64,33 +65,11 @@ final class ReadContext {
RefReader get refReader => _refReader;

@internal
bool hasContextObject(Object key) {
return _contextObjects.containsKey(key);
}

@internal
T? getContextObject<T>(Object key) {
return _contextObjects[key] as T?;
}
StructReadSlots? get structReadSlots => _structReadSlots;

@internal
Object? replaceContextObject(Object key, Object? next) {
final previous = _contextObjects[key];
if (next == null) {
_contextObjects.remove(key);
} else {
_contextObjects[key] = next;
}
return previous;
}

@internal
void restoreContextObject(Object key, Object? previous) {
if (previous == null) {
_contextObjects.remove(key);
} else {
_contextObjects[key] = previous;
}
set structReadSlots(StructReadSlots? value) {
_structReadSlots = value;
}

@internal
Expand Down
34 changes: 6 additions & 28 deletions dart/packages/fory/lib/src/context/write_context.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@ import 'package:fory/src/serializer/collection_serializers.dart';
import 'package:fory/src/serializer/map_serializers.dart';
import 'package:fory/src/serializer/primitive_serializers.dart';
import 'package:fory/src/serializer/scalar_serializers.dart';
import 'package:fory/src/serializer/struct_slots.dart';
import 'package:fory/src/serializer/typed_array_serializers.dart';
import 'package:fory/src/types/float16.dart';
import 'package:fory/src/types/local_date.dart';
Expand All @@ -35,8 +36,7 @@ final class WriteContext {
late Buffer _buffer;
final LinkedHashMap<TypeDef, int> _typeDefIds =
LinkedHashMap<TypeDef, int>.identity();
final LinkedHashMap<Object, Object?> _contextObjects =
LinkedHashMap<Object, Object?>.identity();
StructWriteSlots? _structWriteSlots;
bool _rootTrackRef = false;
int _depth = 0;

Expand All @@ -59,7 +59,7 @@ final class WriteContext {
_typeDefIds.clear();
_refWriter.reset();
_metaStringWriter.reset();
_contextObjects.clear();
_structWriteSlots = null;
_rootTrackRef = false;
_depth = 0;
}
Expand All @@ -77,33 +77,11 @@ final class WriteContext {
bool get rootTrackRef => _rootTrackRef;

@internal
bool hasContextObject(Object key) {
return _contextObjects.containsKey(key);
}
StructWriteSlots? get structWriteSlots => _structWriteSlots;

@internal
T? getContextObject<T>(Object key) {
return _contextObjects[key] as T?;
}

@internal
Object? replaceContextObject(Object key, Object? next) {
final previous = _contextObjects[key];
if (next == null) {
_contextObjects.remove(key);
} else {
_contextObjects[key] = next;
}
return previous;
}

@internal
void restoreContextObject(Object key, Object? previous) {
if (previous == null) {
_contextObjects.remove(key);
} else {
_contextObjects[key] = previous;
}
set structWriteSlots(StructWriteSlots? value) {
_structWriteSlots = value;
}

/// Records entry into one more nested write frame.
Expand Down
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