gtsocial-umbx

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helpers.go (2850B)


      1 package mangler
      2 
      3 import (
      4 	"reflect"
      5 	"unsafe"
      6 )
      7 
      8 type (
      9 	// serializing interfacing types.
     10 	stringer        interface{ String() string }
     11 	binarymarshaler interface{ MarshalBinary() ([]byte, error) }
     12 	textmarshaler   interface{ MarshalText() ([]byte, error) }
     13 	jsonmarshaler   interface{ MarshalJSON() ([]byte, error) }
     14 )
     15 
     16 func append_uint16(b []byte, u uint16) []byte {
     17 	return append(b, // LE
     18 		byte(u),
     19 		byte(u>>8),
     20 	)
     21 }
     22 
     23 func append_uint32(b []byte, u uint32) []byte {
     24 	return append(b, // LE
     25 		byte(u),
     26 		byte(u>>8),
     27 		byte(u>>16),
     28 		byte(u>>24),
     29 	)
     30 }
     31 
     32 func append_uint64(b []byte, u uint64) []byte {
     33 	return append(b, // LE
     34 		byte(u),
     35 		byte(u>>8),
     36 		byte(u>>16),
     37 		byte(u>>24),
     38 		byte(u>>32),
     39 		byte(u>>40),
     40 		byte(u>>48),
     41 		byte(u>>56),
     42 	)
     43 }
     44 
     45 func deref_ptr_mangler(mangle Mangler, count int) rMangler {
     46 	return func(buf []byte, v reflect.Value) []byte {
     47 		for i := 0; i < count; i++ {
     48 			// Check for nil
     49 			if v.IsNil() {
     50 				buf = append(buf, '0')
     51 				return buf
     52 			}
     53 
     54 			// Further deref ptr
     55 			buf = append(buf, '1')
     56 			v = v.Elem()
     57 		}
     58 
     59 		// Mangle fully deref'd ptr
     60 		return mangle(buf, v.Interface())
     61 	}
     62 }
     63 
     64 func deref_ptr_rmangler(mangle rMangler, count int) rMangler {
     65 	return func(buf []byte, v reflect.Value) []byte {
     66 		for i := 0; i < count; i++ {
     67 			// Check for nil
     68 			if v.IsNil() {
     69 				buf = append(buf, '0')
     70 				return buf
     71 			}
     72 
     73 			// Further deref ptr
     74 			buf = append(buf, '1')
     75 			v = v.Elem()
     76 		}
     77 
     78 		// Mangle fully deref'd ptr
     79 		return mangle(buf, v)
     80 	}
     81 }
     82 
     83 func array_to_slice_mangler(mangle Mangler) rMangler {
     84 	return func(buf []byte, v reflect.Value) []byte {
     85 		// Get slice of whole array
     86 		v = v.Slice(0, v.Len())
     87 
     88 		// Mangle as known slice type
     89 		return mangle(buf, v.Interface())
     90 	}
     91 }
     92 
     93 func iter_array_mangler(mangle Mangler) rMangler {
     94 	return func(buf []byte, v reflect.Value) []byte {
     95 		n := v.Len()
     96 		for i := 0; i < n; i++ {
     97 			buf = mangle(buf, v.Index(i).Interface())
     98 			buf = append(buf, ',')
     99 		}
    100 		if n > 0 {
    101 			buf = buf[:len(buf)-1]
    102 		}
    103 		return buf
    104 	}
    105 }
    106 
    107 func iter_array_rmangler(mangle rMangler) rMangler {
    108 	return func(buf []byte, v reflect.Value) []byte {
    109 		n := v.Len()
    110 		for i := 0; i < n; i++ {
    111 			buf = mangle(buf, v.Index(i))
    112 			buf = append(buf, ',')
    113 		}
    114 		if n > 0 {
    115 			buf = buf[:len(buf)-1]
    116 		}
    117 		return buf
    118 	}
    119 }
    120 
    121 func iter_map_rmangler(kMangle, vMangle rMangler) rMangler {
    122 	return func(buf []byte, v reflect.Value) []byte {
    123 		r := v.MapRange()
    124 		for r.Next() {
    125 			buf = kMangle(buf, r.Key())
    126 			buf = append(buf, ':')
    127 			buf = vMangle(buf, r.Value())
    128 			buf = append(buf, ',')
    129 		}
    130 		if v.Len() > 0 {
    131 			buf = buf[:len(buf)-1]
    132 		}
    133 		return buf
    134 	}
    135 }
    136 
    137 // iface_value returns the raw value ptr for input boxed within interface{} type.
    138 func iface_value(a any) unsafe.Pointer {
    139 	type eface struct {
    140 		Type  unsafe.Pointer
    141 		Value unsafe.Pointer
    142 	}
    143 	return (*eface)(unsafe.Pointer(&a)).Value
    144 }