internal/impl: add fast-path unmarshal
Benchmarks run with:
go test ./benchmarks/ -bench=Wire -benchtime=500ms -benchmem -count=8
Fast-path vs. parent commit:
name old time/op new time/op delta
Wire/Unmarshal/google_message1_proto2-12 1.35µs ± 2% 0.45µs ± 4% -67.01% (p=0.000 n=8+8)
Wire/Unmarshal/google_message1_proto3-12 1.07µs ± 1% 0.31µs ± 1% -71.04% (p=0.000 n=8+8)
Wire/Unmarshal/google_message2-12 691µs ± 2% 188µs ± 2% -72.78% (p=0.000 n=7+8)
name old allocs/op new allocs/op delta
Wire/Unmarshal/google_message1_proto2-12 60.0 ± 0% 25.0 ± 0% -58.33% (p=0.000 n=8+8)
Wire/Unmarshal/google_message1_proto3-12 42.0 ± 0% 7.0 ± 0% -83.33% (p=0.000 n=8+8)
Wire/Unmarshal/google_message2-12 28.6k ± 0% 8.5k ± 0% -70.34% (p=0.000 n=8+8)
Fast-path vs. -v1:
name old time/op new time/op delta
Wire/Unmarshal/google_message1_proto2-12 702ns ± 1% 445ns ± 4% -36.58% (p=0.000 n=8+8)
Wire/Unmarshal/google_message1_proto3-12 604ns ± 1% 311ns ± 1% -48.54% (p=0.000 n=8+8)
Wire/Unmarshal/google_message2-12 179µs ± 3% 188µs ± 2% +5.30% (p=0.000 n=7+8)
name old allocs/op new allocs/op delta
Wire/Unmarshal/google_message1_proto2-12 26.0 ± 0% 25.0 ± 0% -3.85% (p=0.000 n=8+8)
Wire/Unmarshal/google_message1_proto3-12 8.00 ± 0% 7.00 ± 0% -12.50% (p=0.000 n=8+8)
Wire/Unmarshal/google_message2-12 8.49k ± 0% 8.49k ± 0% -0.01% (p=0.000 n=8+8)
Change-Id: I6247ac3fd66a63d9acb902cbd192094ee3d151c3
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/185147
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
diff --git a/internal/impl/pointer_unsafe.go b/internal/impl/pointer_unsafe.go
index bd5ab4b..ceca3b2 100644
--- a/internal/impl/pointer_unsafe.go
+++ b/internal/impl/pointer_unsafe.go
@@ -115,3 +115,13 @@
// message type. We load it as []pointer.
return *(*[]pointer)(p.p)
}
+
+// AppendPointerSlice appends v to p, which must be a []*T.
+func (p pointer) AppendPointerSlice(v pointer) {
+ *(*[]pointer)(p.p) = append(*(*[]pointer)(p.p), v)
+}
+
+// SetPointer sets *p to v.
+func (p pointer) SetPointer(v pointer) {
+ *(*unsafe.Pointer)(p.p) = (unsafe.Pointer)(v.p)
+}