internal/impl: add fast-path marshal implementation
This is a port of the v1 table marshaler, with some substantial
cleanup and refactoring.
Benchstat results from the protobuf reference benchmark data comparing the
v1 package with v2, with AllowPartial:true set for the new package. This
is not an apples-to-apples comparison, since v1 doesn't have a way to
disable required field checks. Required field checks in v2 package
currently go through reflection, which performs terribly; my initial
experimentation indicates that fast-path required field checks will
not add a large amount of cost; these results are incomplete but not
wholly inaccurate.
name old time/op new time/op delta
/dataset.google_message3_1.pb/Marshal-12 219ms ± 1% 232ms ± 1% +5.85% (p=0.004 n=6+5)
/dataset.google_message2.pb/Marshal-12 261µs ± 3% 248µs ± 1% -5.14% (p=0.002 n=6+6)
/dataset.google_message1_proto2.pb/Marshal-12 681ns ± 2% 637ns ± 3% -6.53% (p=0.002 n=6+6)
/dataset.google_message1_proto3.pb/Marshal-12 1.10µs ± 8% 0.99µs ± 3% -9.63% (p=0.002 n=6+6)
/dataset.google_message3_3.pb/Marshal-12 44.2ms ± 3% 35.2ms ± 1% -20.28% (p=0.004 n=6+5)
/dataset.google_message4.pb/Marshal-12 91.4ms ± 2% 94.9ms ± 2% +3.78% (p=0.002 n=6+6)
/dataset.google_message3_2.pb/Marshal-12 78.7ms ± 6% 80.8ms ± 4% ~ (p=0.310 n=6+6)
/dataset.google_message3_4.pb/Marshal-12 10.6ms ± 3% 10.6ms ± 8% ~ (p=0.662 n=5+6)
/dataset.google_message3_5.pb/Marshal-12 675ms ± 4% 510ms ± 2% -24.40% (p=0.002 n=6+6)
/dataset.google_message3_1.pb/Marshal 219ms ± 1% 236ms ± 7% +8.06% (p=0.004 n=5+6)
/dataset.google_message2.pb/Marshal 257µs ± 1% 250µs ± 3% ~ (p=0.052 n=5+6)
/dataset.google_message1_proto2.pb/Marshal 685ns ± 1% 628ns ± 1% -8.41% (p=0.008 n=5+5)
/dataset.google_message1_proto3.pb/Marshal 1.08µs ± 1% 0.98µs ± 2% -9.31% (p=0.004 n=5+6)
/dataset.google_message3_3.pb/Marshal 43.7ms ± 1% 35.1ms ± 1% -19.76% (p=0.002 n=6+6)
/dataset.google_message4.pb/Marshal 93.4ms ± 4% 94.9ms ± 2% ~ (p=0.180 n=6+6)
/dataset.google_message3_2.pb/Marshal 105ms ± 2% 98ms ± 7% -6.81% (p=0.009 n=5+6)
/dataset.google_message3_4.pb/Marshal 16.3ms ± 6% 15.7ms ± 3% -3.44% (p=0.041 n=6+6)
/dataset.google_message3_5.pb/Marshal 676ms ± 4% 504ms ± 2% -25.50% (p=0.004 n=6+5)
Change-Id: I72cc4597117f4cf5d236ef505777d49dd4a5f75d
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/171020
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
diff --git a/internal/impl/message_field.go b/internal/impl/message_field.go
index 356ec78..72f4523 100644
--- a/internal/impl/message_field.go
+++ b/internal/impl/message_field.go
@@ -9,18 +9,26 @@
"math"
"reflect"
+ "google.golang.org/protobuf/internal/encoding/wire"
pvalue "google.golang.org/protobuf/internal/value"
pref "google.golang.org/protobuf/reflect/protoreflect"
)
type fieldInfo struct {
- // TODO: specialize marshal and unmarshal functions?
-
+ // These fields are used for protobuf reflection support.
has func(pointer) bool
get func(pointer) pref.Value
set func(pointer, pref.Value)
clear func(pointer)
newMessage func() pref.Message
+
+ // These fields are used for fast-path functions.
+ funcs pointerCoderFuncs // fast-path per-field functions
+ num pref.FieldNumber // field number
+ offset offset // struct field offset
+ wiretag uint64 // field tag (number + wire type)
+ tagsize int // size of the varint-encoded tag
+ isPointer bool // true if IsNil may be called on the struct field
}
func fieldInfoForOneof(fd pref.FieldDescriptor, fs reflect.StructField, ot reflect.Type) fieldInfo {
@@ -82,6 +90,8 @@
// This is only valid for messages and panics for other kinds.
return conv.MessageType.New()
},
+ offset: fieldOffset,
+ isPointer: true,
}
}
@@ -92,6 +102,7 @@
}
keyConv := pvalue.NewLegacyConverter(ft.Key(), fd.MapKey().Kind(), legacyWrapper)
valConv := pvalue.NewLegacyConverter(ft.Elem(), fd.MapValue().Kind(), legacyWrapper)
+ wiretag := wire.EncodeTag(fd.Number(), wireTypes[fd.Kind()])
fieldOffset := offsetOf(fs)
// TODO: Implement unsafe fast path?
return fieldInfo{
@@ -118,6 +129,11 @@
rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem()
rv.Set(reflect.Zero(rv.Type()))
},
+ funcs: encoderFuncsForMap(fd, ft),
+ offset: fieldOffset,
+ wiretag: wiretag,
+ tagsize: wire.SizeVarint(wiretag),
+ isPointer: true,
}
}
@@ -127,6 +143,12 @@
panic(fmt.Sprintf("invalid type: got %v, want slice kind", ft))
}
conv := pvalue.NewLegacyConverter(ft.Elem(), fd.Kind(), legacyWrapper)
+ var wiretag uint64
+ if !fd.IsPacked() {
+ wiretag = wire.EncodeTag(fd.Number(), wireTypes[fd.Kind()])
+ } else {
+ wiretag = wire.EncodeTag(fd.Number(), wire.BytesType)
+ }
fieldOffset := offsetOf(fs)
// TODO: Implement unsafe fast path?
return fieldInfo{
@@ -153,6 +175,11 @@
rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem()
rv.Set(reflect.Zero(rv.Type()))
},
+ funcs: fieldCoder(fd, ft),
+ offset: fieldOffset,
+ wiretag: wiretag,
+ tagsize: wire.SizeVarint(wiretag),
+ isPointer: true,
}
}
@@ -160,6 +187,7 @@
func fieldInfoForScalar(fd pref.FieldDescriptor, fs reflect.StructField) fieldInfo {
ft := fs.Type
+ funcs := fieldCoder(fd, ft)
nullable := fd.Syntax() == pref.Proto2
if nullable {
if ft.Kind() != reflect.Ptr && ft.Kind() != reflect.Slice {
@@ -171,6 +199,7 @@
}
conv := pvalue.NewLegacyConverter(ft, fd.Kind(), legacyWrapper)
fieldOffset := offsetOf(fs)
+ wiretag := wire.EncodeTag(fd.Number(), wireTypes[fd.Kind()])
// TODO: Implement unsafe fast path?
return fieldInfo{
has: func(p pointer) bool {
@@ -228,6 +257,11 @@
rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem()
rv.Set(reflect.Zero(rv.Type()))
},
+ funcs: funcs,
+ offset: fieldOffset,
+ isPointer: nullable,
+ wiretag: wiretag,
+ tagsize: wire.SizeVarint(wiretag),
}
}
@@ -236,6 +270,7 @@
conv := pvalue.NewLegacyConverter(ft, fd.Kind(), legacyWrapper)
fieldOffset := offsetOf(fs)
// TODO: Implement unsafe fast path?
+ wiretag := wire.EncodeTag(fd.Number(), wireTypes[fd.Kind()])
return fieldInfo{
has: func(p pointer) bool {
if p.IsNil() {
@@ -268,6 +303,11 @@
newMessage: func() pref.Message {
return conv.MessageType.New()
},
+ funcs: fieldCoder(fd, ft),
+ offset: fieldOffset,
+ isPointer: true,
+ wiretag: wiretag,
+ tagsize: wire.SizeVarint(wiretag),
}
}