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flatbuffers
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Go: CreateString now needs zero allocs. 

Big speed boost for the typical use case of building with strings.
This commit is contained in:
rw 2015-05-20 12:00:44 -07:00
parent 6fffa2a14d
commit c127cf78c2
2 changed files with 25 additions and 10 deletions
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10
go/builder.go
View File

@ -281,7 +281,15 @@ func (b *Builder) EndVector(vectorNumElems int) UOffsetT {
// CreateString writes a null-terminated string as a vector.
func (b *Builder) CreateString(s string) UOffsetT {
return b.CreateByteString([]byte(s))
b.Prep(int(SizeUOffsetT), (len(s)+1)*SizeByte)
b.PlaceByte(0)
l := UOffsetT(len(s))
b.head -= l
copy(b.Bytes[b.head:b.head+l], s)
return b.EndVector(len(s))
}
// CreateByteString writes a byte slice as a string (null-terminated).

25
tests/go_test.go
View File

@ -533,7 +533,14 @@ func CheckByteLayout(fail func(string, ...interface{})) {
check([]byte{4, 0, 0, 0, 'm', 'o', 'o', 'p', 0, 0, 0, 0, // 0-terminated, 3-byte pad
3, 0, 0, 0, 'f', 'o', 'o', 0})
// test 6b: CreateByteString
// test 6b: CreateString unicode
b = flatbuffers.NewBuilder(0)
b.CreateString("日本語")
check([]byte{9, 0, 0, 0, 230, 151, 165, 230, 156, 172, 232, 170, 158, 0, // null-terminated, 2-byte pad
0, 0})
// test 6c: CreateByteString
b = flatbuffers.NewBuilder(0)
b.CreateByteString([]byte("foo"))
@ -1263,10 +1270,10 @@ func BenchmarkBuildGold(b *testing.B) {
buf, offset := CheckGeneratedBuild(b.Fatalf)
bytes_length := int64(len(buf[offset:]))
reuse_str := []byte("MyMonster")
reuse_test1 := []byte("test1")
reuse_test2 := []byte("test2")
reuse_fred := []byte("Fred")
reuse_str := "MyMonster"
reuse_test1 := "test1"
reuse_test2 := "test2"
reuse_fred := "Fred"
b.SetBytes(bytes_length)
bldr := flatbuffers.NewBuilder(0)
@ -1275,10 +1282,10 @@ func BenchmarkBuildGold(b *testing.B) {
for i := 0; i < b.N; i++ {
bldr.Reset()
str := bldr.CreateByteString(reuse_str)
test1 := bldr.CreateByteString(reuse_test1)
test2 := bldr.CreateByteString(reuse_test2)
fred := bldr.CreateByteString(reuse_fred)
str := bldr.CreateString(reuse_str)
test1 := bldr.CreateString(reuse_test1)
test2 := bldr.CreateString(reuse_test2)
fred := bldr.CreateString(reuse_fred)
example.MonsterStartInventoryVector(bldr, 5)
bldr.PrependByte(4)