Skip to content

Commit

Permalink
~30% deserialization speedup for long repeated fields by reducing box…
Browse files Browse the repository at this point in the history 
…ing overhead.

Also memoize storage lookup from previously deserialized field, though that seems to have only a minor impact since the lookup is fast already.
  • Loading branch information
@ignatz
ignatz committed Feb 1, 2024
1 parent a293fb9 commit a1c7bc5
Showing 1 changed file with 110 additions and 37 deletions.
147 changes: 110 additions & 37 deletions protobuf/lib/src/protobuf/coded_buffer.dart
View file
Original file line number Diff line number Diff line change
Expand Up @@ -33,8 +33,19 @@ void _mergeFromCodedBufferReader(BuilderInfo meta, _FieldSet fs,
CodedBufferReader input, ExtensionRegistry registry) {
ArgumentError.checkNotNull(registry);
fs._ensureWritable();

// Micro-optimization: cache the storage lookup for repeated fields.
var prevTag = -1;
List? cachedList;

while (true) {
final tag = input.readTag();
// If the current field's tag is different from previous, invalidate cache.
if (tag != prevTag) {
cachedList = null;
prevTag = tag;
}

if (tag == 0) return;
final wireType = tag & 0x7;
final tagNumber = tag >> 3;
Expand Down Expand Up @@ -128,63 +139,133 @@ void _mergeFromCodedBufferReader(BuilderInfo meta, _FieldSet fs,
}
break;
case PbFieldType._REPEATED_BOOL:
_readPackable(meta, fs, input, wireType, fi, input.readBool);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
if (wireType == WIRETYPE_LENGTH_DELIMITED) {
_readPacked(input, () => list.add(input.readBool()));
} else {
list.add(input.readBool());
}
break;
case PbFieldType._REPEATED_BYTES:
fs._ensureRepeatedField(meta, fi).add(input.readBytes());
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
list.add(input.readBytes());
break;
case PbFieldType._REPEATED_STRING:
fs._ensureRepeatedField(meta, fi).add(input.readString());
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
list.add(input.readString());
break;
case PbFieldType._REPEATED_FLOAT:
_readPackable(meta, fs, input, wireType, fi, input.readFloat);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
if (wireType == WIRETYPE_LENGTH_DELIMITED) {
_readPacked(input, () => list.add(input.readFloat()));
} else {
list.add(input.readFloat());
}
break;
case PbFieldType._REPEATED_DOUBLE:
_readPackable(meta, fs, input, wireType, fi, input.readDouble);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
if (wireType == WIRETYPE_LENGTH_DELIMITED) {
_readPacked(input, () => list.add(input.readDouble()));
} else {
list.add(input.readDouble());
}
break;
case PbFieldType._REPEATED_ENUM:
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
_readPackableToListEnum(
meta, fs, input, wireType, fi, tagNumber, registry);
list, meta, fs, input, wireType, fi, tagNumber, registry);
break;
case PbFieldType._REPEATED_GROUP:
final subMessage = meta._makeEmptyMessage(tagNumber, registry);
input.readGroup(tagNumber, subMessage, registry);
fs._ensureRepeatedField(meta, fi).add(subMessage);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
list.add(subMessage);
break;
case PbFieldType._REPEATED_INT32:
_readPackable(meta, fs, input, wireType, fi, input.readInt32);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
if (wireType == WIRETYPE_LENGTH_DELIMITED) {
_readPacked(input, () => list.add(input.readInt32()));
} else {
list.add(input.readInt32());
}
break;
case PbFieldType._REPEATED_INT64:
_readPackable(meta, fs, input, wireType, fi, input.readInt64);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
if (wireType == WIRETYPE_LENGTH_DELIMITED) {
_readPacked(input, () => list.add(input.readInt64()));
} else {
list.add(input.readInt64());
}
break;
case PbFieldType._REPEATED_SINT32:
_readPackable(meta, fs, input, wireType, fi, input.readSint32);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
if (wireType == WIRETYPE_LENGTH_DELIMITED) {
_readPacked(input, () => list.add(input.readSint32()));
} else {
list.add(input.readSint32());
}
break;
case PbFieldType._REPEATED_SINT64:
_readPackable(meta, fs, input, wireType, fi, input.readSint64);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
if (wireType == WIRETYPE_LENGTH_DELIMITED) {
_readPacked(input, () => list.add(input.readSint32()));
} else {
list.add(input.readSint32());
}
break;
case PbFieldType._REPEATED_UINT32:
_readPackable(meta, fs, input, wireType, fi, input.readUint32);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
if (wireType == WIRETYPE_LENGTH_DELIMITED) {
_readPacked(input, () => list.add(input.readUint32()));
} else {
list.add(input.readUint32());
}
break;
case PbFieldType._REPEATED_UINT64:
_readPackable(meta, fs, input, wireType, fi, input.readUint64);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
if (wireType == WIRETYPE_LENGTH_DELIMITED) {
_readPacked(input, () => list.add(input.readUint64()));
} else {
list.add(input.readUint64());
}
break;
case PbFieldType._REPEATED_FIXED32:
_readPackable(meta, fs, input, wireType, fi, input.readFixed32);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
if (wireType == WIRETYPE_LENGTH_DELIMITED) {
_readPacked(input, () => list.add(input.readFixed32()));
} else {
list.add(input.readFixed32());
}
break;
case PbFieldType._REPEATED_FIXED64:
_readPackable(meta, fs, input, wireType, fi, input.readFixed64);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
if (wireType == WIRETYPE_LENGTH_DELIMITED) {
_readPacked(input, () => list.add(input.readFixed64()));
} else {
list.add(input.readFixed64());
}
break;
case PbFieldType._REPEATED_SFIXED32:
_readPackable(meta, fs, input, wireType, fi, input.readSfixed32);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
if (wireType == WIRETYPE_LENGTH_DELIMITED) {
_readPacked(input, () => list.add(input.readSfixed32()));
} else {
list.add(input.readSfixed32());
}
break;
case PbFieldType._REPEATED_SFIXED64:
_readPackable(meta, fs, input, wireType, fi, input.readSfixed64);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
if (wireType == WIRETYPE_LENGTH_DELIMITED) {
_readPacked(input, () => list.add(input.readSfixed64()));
} else {
list.add(input.readSfixed64());
}
break;
case PbFieldType._REPEATED_MESSAGE:
final subMessage = meta._makeEmptyMessage(tagNumber, registry);
input.readMessage(subMessage, registry);
fs._ensureRepeatedField(meta, fi).add(subMessage);
final list = cachedList ??= fs._ensureRepeatedField(meta, fi);
list.add(subMessage);
break;
case PbFieldType._MAP:
final mapFieldInfo = fi as MapFieldInfo;
Expand All @@ -199,21 +280,25 @@ void _mergeFromCodedBufferReader(BuilderInfo meta, _FieldSet fs,
}
}

void _readPackable(BuilderInfo meta, _FieldSet fs, CodedBufferReader input,
int wireType, FieldInfo fi, Function() readFunc) {
void readToList(List list) => list.add(readFunc());
_readPackableToList(meta, fs, input, wireType, fi, readToList);
void _readPacked(CodedBufferReader input, void Function() readFunc) {
input._withLimit(input.readInt32(), () {
while (!input.isAtEnd()) {
readFunc();
}
});
}

void _readPackableToListEnum(
List list,
BuilderInfo meta,
_FieldSet fs,
CodedBufferReader input,
int wireType,
FieldInfo fi,
int tagNumber,
ExtensionRegistry registry) {
void readToList(List list) {
// final list = fs._ensureRepeatedField(meta, fi);
void readToList() {
final rawValue = input.readEnum();
final value = meta._decodeEnum(tagNumber, registry, rawValue);
if (value == null) {
Expand All @@ -224,27 +309,15 @@ void _readPackableToListEnum(
}
}

_readPackableToList(meta, fs, input, wireType, fi, readToList);
}

void _readPackableToList(
BuilderInfo meta,
_FieldSet fs,
CodedBufferReader input,
int wireType,
FieldInfo fi,
Function(List) readToList) {
final list = fs._ensureRepeatedField(meta, fi);

if (wireType == WIRETYPE_LENGTH_DELIMITED) {
// Packed.
input._withLimit(input.readInt32(), () {
while (!input.isAtEnd()) {
readToList(list);
readToList();
}
});
} else {
// Not packed.
readToList(list);
readToList();
}
}

0 comments on commit a1c7bc5

Please sign in to comment.