syncthing/vendor/github.com/gogo/protobuf/proto/pointer_unsafe_gogo.go

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// Protocol Buffers for Go with Gadgets
//
// Copyright (c) 2013, The GoGo Authors. All rights reserved.
// http://github.com/gogo/protobuf
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// +build !appengine,!js
// This file contains the implementation of the proto field accesses using package unsafe.
package proto
import (
"reflect"
"unsafe"
)
func structPointer_InterfaceAt(p structPointer, f field, t reflect.Type) interface{} {
point := unsafe.Pointer(uintptr(p) + uintptr(f))
r := reflect.NewAt(t, point)
return r.Interface()
}
func structPointer_InterfaceRef(p structPointer, f field, t reflect.Type) interface{} {
point := unsafe.Pointer(uintptr(p) + uintptr(f))
r := reflect.NewAt(t, point)
if r.Elem().IsNil() {
return nil
}
return r.Elem().Interface()
}
func copyUintPtr(oldptr, newptr uintptr, size int) {
oldbytes := make([]byte, 0)
oldslice := (*reflect.SliceHeader)(unsafe.Pointer(&oldbytes))
oldslice.Data = oldptr
oldslice.Len = size
oldslice.Cap = size
newbytes := make([]byte, 0)
newslice := (*reflect.SliceHeader)(unsafe.Pointer(&newbytes))
newslice.Data = newptr
newslice.Len = size
newslice.Cap = size
copy(newbytes, oldbytes)
}
func structPointer_Copy(oldptr structPointer, newptr structPointer, size int) {
copyUintPtr(uintptr(oldptr), uintptr(newptr), size)
}
func appendStructPointer(base structPointer, f field, typ reflect.Type) structPointer {
size := typ.Elem().Size()
oldHeader := structPointer_GetSliceHeader(base, f)
oldSlice := reflect.NewAt(typ, unsafe.Pointer(oldHeader)).Elem()
newLen := oldHeader.Len + 1
newSlice := reflect.MakeSlice(typ, newLen, newLen)
reflect.Copy(newSlice, oldSlice)
bas := toStructPointer(newSlice)
oldHeader.Data = uintptr(bas)
oldHeader.Len = newLen
oldHeader.Cap = newLen
return structPointer(unsafe.Pointer(uintptr(unsafe.Pointer(bas)) + uintptr(uintptr(newLen-1)*size)))
}
func structPointer_FieldPointer(p structPointer, f field) structPointer {
return structPointer(unsafe.Pointer(uintptr(p) + uintptr(f)))
}
func structPointer_GetRefStructPointer(p structPointer, f field) structPointer {
return structPointer((*structPointer)(unsafe.Pointer(uintptr(p) + uintptr(f))))
}
func structPointer_GetSliceHeader(p structPointer, f field) *reflect.SliceHeader {
return (*reflect.SliceHeader)(unsafe.Pointer(uintptr(p) + uintptr(f)))
}
func structPointer_Add(p structPointer, size field) structPointer {
return structPointer(unsafe.Pointer(uintptr(p) + uintptr(size)))
}
func structPointer_Len(p structPointer, f field) int {
return len(*(*[]interface{})(unsafe.Pointer(structPointer_GetRefStructPointer(p, f))))
}
func structPointer_StructRefSlice(p structPointer, f field, size uintptr) *structRefSlice {
return &structRefSlice{p: p, f: f, size: size}
}
// A structRefSlice represents a slice of structs (themselves submessages or groups).
type structRefSlice struct {
p structPointer
f field
size uintptr
}
func (v *structRefSlice) Len() int {
return structPointer_Len(v.p, v.f)
}
func (v *structRefSlice) Index(i int) structPointer {
ss := structPointer_GetStructPointer(v.p, v.f)
ss1 := structPointer_GetRefStructPointer(ss, 0)
return structPointer_Add(ss1, field(uintptr(i)*v.size))
}