github.com/segmentio/kafka-go@v0.4.48-0.20240318174348-3f6244eb34fd/protocol/reflect_unsafe.go (about)

     1  //go:build unsafe
     2  // +build unsafe
     3  
     4  package protocol
     5  
     6  import (
     7  	"reflect"
     8  	"unsafe"
     9  )
    10  
    11  type iface struct {
    12  	typ unsafe.Pointer
    13  	ptr unsafe.Pointer
    14  }
    15  
    16  type slice struct {
    17  	ptr unsafe.Pointer
    18  	len int
    19  	cap int
    20  }
    21  
    22  type index uintptr
    23  
    24  type _type struct {
    25  	ptr unsafe.Pointer
    26  }
    27  
    28  func typeOf(x interface{}) _type {
    29  	return _type{ptr: ((*iface)(unsafe.Pointer(&x))).typ}
    30  }
    31  
    32  func elemTypeOf(x interface{}) _type {
    33  	return makeType(reflect.TypeOf(x).Elem())
    34  }
    35  
    36  func makeType(t reflect.Type) _type {
    37  	return _type{ptr: ((*iface)(unsafe.Pointer(&t))).ptr}
    38  }
    39  
    40  type value struct {
    41  	ptr unsafe.Pointer
    42  }
    43  
    44  func nonAddressableValueOf(x interface{}) value {
    45  	return valueOf(x)
    46  }
    47  
    48  func valueOf(x interface{}) value {
    49  	return value{ptr: ((*iface)(unsafe.Pointer(&x))).ptr}
    50  }
    51  
    52  func makeValue(t reflect.Type) value {
    53  	return value{ptr: unsafe.Pointer(reflect.New(t).Pointer())}
    54  }
    55  
    56  func (v value) bool() bool { return *(*bool)(v.ptr) }
    57  
    58  func (v value) int8() int8 { return *(*int8)(v.ptr) }
    59  
    60  func (v value) int16() int16 { return *(*int16)(v.ptr) }
    61  
    62  func (v value) int32() int32 { return *(*int32)(v.ptr) }
    63  
    64  func (v value) int64() int64 { return *(*int64)(v.ptr) }
    65  
    66  func (v value) float64() float64 { return *(*float64)(v.ptr) }
    67  
    68  func (v value) string() string { return *(*string)(v.ptr) }
    69  
    70  func (v value) bytes() []byte { return *(*[]byte)(v.ptr) }
    71  
    72  func (v value) iface(t reflect.Type) interface{} {
    73  	return *(*interface{})(unsafe.Pointer(&iface{
    74  		typ: ((*iface)(unsafe.Pointer(&t))).ptr,
    75  		ptr: v.ptr,
    76  	}))
    77  }
    78  
    79  func (v value) array(t reflect.Type) array {
    80  	return array{
    81  		size: uintptr(t.Size()),
    82  		elem: ((*slice)(v.ptr)).ptr,
    83  		len:  ((*slice)(v.ptr)).len,
    84  	}
    85  }
    86  
    87  func (v value) setBool(b bool) { *(*bool)(v.ptr) = b }
    88  
    89  func (v value) setInt8(i int8) { *(*int8)(v.ptr) = i }
    90  
    91  func (v value) setInt16(i int16) { *(*int16)(v.ptr) = i }
    92  
    93  func (v value) setInt32(i int32) { *(*int32)(v.ptr) = i }
    94  
    95  func (v value) setInt64(i int64) { *(*int64)(v.ptr) = i }
    96  
    97  func (v value) setFloat64(f float64) { *(*float64)(v.ptr) = f }
    98  
    99  func (v value) setString(s string) { *(*string)(v.ptr) = s }
   100  
   101  func (v value) setBytes(b []byte) { *(*[]byte)(v.ptr) = b }
   102  
   103  func (v value) setArray(a array) { *(*slice)(v.ptr) = slice{ptr: a.elem, len: a.len, cap: a.len} }
   104  
   105  func (v value) fieldByIndex(i index) value {
   106  	return value{ptr: unsafe.Pointer(uintptr(v.ptr) + uintptr(i))}
   107  }
   108  
   109  type array struct {
   110  	elem unsafe.Pointer
   111  	size uintptr
   112  	len  int
   113  }
   114  
   115  var (
   116  	emptyArray struct{}
   117  )
   118  
   119  func makeArray(t reflect.Type, n int) array {
   120  	var elem unsafe.Pointer
   121  	var size = uintptr(t.Size())
   122  	if n == 0 {
   123  		elem = unsafe.Pointer(&emptyArray)
   124  	} else {
   125  		elem = unsafe_NewArray(((*iface)(unsafe.Pointer(&t))).ptr, n)
   126  	}
   127  	return array{elem: elem, size: size, len: n}
   128  }
   129  
   130  func (a array) index(i int) value {
   131  	return value{ptr: unsafe.Pointer(uintptr(a.elem) + (uintptr(i) * a.size))}
   132  }
   133  
   134  func (a array) length() int { return a.len }
   135  
   136  func (a array) isNil() bool { return a.elem == nil }
   137  
   138  func indexOf(s reflect.StructField) index { return index(s.Offset) }
   139  
   140  func bytesToString(b []byte) string { return *(*string)(unsafe.Pointer(&b)) }
   141  
   142  //go:linkname unsafe_NewArray reflect.unsafe_NewArray
   143  func unsafe_NewArray(rtype unsafe.Pointer, length int) unsafe.Pointer