gotosocial/vendor/github.com/bytedance/sonic/internal/rt/fastmem.go

125 lines
3.2 KiB
Go

/*
* Copyright 2021 ByteDance Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package rt
import (
`unsafe`
`reflect`
)
//go:nosplit
func Get16(v []byte) int16 {
return *(*int16)((*GoSlice)(unsafe.Pointer(&v)).Ptr)
}
//go:nosplit
func Get32(v []byte) int32 {
return *(*int32)((*GoSlice)(unsafe.Pointer(&v)).Ptr)
}
//go:nosplit
func Get64(v []byte) int64 {
return *(*int64)((*GoSlice)(unsafe.Pointer(&v)).Ptr)
}
//go:nosplit
func Mem2Str(v []byte) (s string) {
(*GoString)(unsafe.Pointer(&s)).Len = (*GoSlice)(unsafe.Pointer(&v)).Len
(*GoString)(unsafe.Pointer(&s)).Ptr = (*GoSlice)(unsafe.Pointer(&v)).Ptr
return
}
//go:nosplit
func Str2Mem(s string) (v []byte) {
(*GoSlice)(unsafe.Pointer(&v)).Cap = (*GoString)(unsafe.Pointer(&s)).Len
(*GoSlice)(unsafe.Pointer(&v)).Len = (*GoString)(unsafe.Pointer(&s)).Len
(*GoSlice)(unsafe.Pointer(&v)).Ptr = (*GoString)(unsafe.Pointer(&s)).Ptr
return
}
func BytesFrom(p unsafe.Pointer, n int, c int) (r []byte) {
(*GoSlice)(unsafe.Pointer(&r)).Ptr = p
(*GoSlice)(unsafe.Pointer(&r)).Len = n
(*GoSlice)(unsafe.Pointer(&r)).Cap = c
return
}
func FuncAddr(f interface{}) unsafe.Pointer {
if vv := UnpackEface(f); vv.Type.Kind() != reflect.Func {
panic("f is not a function")
} else {
return *(*unsafe.Pointer)(vv.Value)
}
}
//go:nocheckptr
func IndexChar(src string, index int) unsafe.Pointer {
return unsafe.Pointer(uintptr((*GoString)(unsafe.Pointer(&src)).Ptr) + uintptr(index))
}
//go:nocheckptr
func IndexByte(ptr []byte, index int) unsafe.Pointer {
return unsafe.Pointer(uintptr((*GoSlice)(unsafe.Pointer(&ptr)).Ptr) + uintptr(index))
}
func GuardSlice(buf *[]byte, n int) {
c := cap(*buf)
l := len(*buf)
if c-l < n {
c = c>>1 + n + l
if c < 32 {
c = 32
}
tmp := make([]byte, l, c)
copy(tmp, *buf)
*buf = tmp
}
}
//go:nosplit
func Ptr2SlicePtr(s unsafe.Pointer, l int, c int) unsafe.Pointer {
slice := &GoSlice{
Ptr: s,
Len: l,
Cap: c,
}
return unsafe.Pointer(slice)
}
//go:nosplit
func StrPtr(s string) unsafe.Pointer {
return (*GoString)(unsafe.Pointer(&s)).Ptr
}
//go:nosplit
func StrFrom(p unsafe.Pointer, n int64) (s string) {
(*GoString)(unsafe.Pointer(&s)).Ptr = p
(*GoString)(unsafe.Pointer(&s)).Len = int(n)
return
}
// NoEscape hides a pointer from escape analysis. NoEscape is
// the identity function but escape analysis doesn't think the
// output depends on the input. NoEscape is inlined and currently
// compiles down to zero instructions.
// USE CAREFULLY!
//go:nosplit
//goland:noinspection GoVetUnsafePointer
func NoEscape(p unsafe.Pointer) unsafe.Pointer {
x := uintptr(p)
return unsafe.Pointer(x ^ 0)
}