github.com/segmentio/encoding@v0.4.0/proto/int32.go (about)

     1  package proto
     2  
     3  import (
     4  	"fmt"
     5  	"math"
     6  	"unsafe"
     7  )
     8  
     9  var int32Codec = codec{
    10  	wire:   varint,
    11  	size:   sizeOfInt32,
    12  	encode: encodeInt32,
    13  	decode: decodeInt32,
    14  }
    15  
    16  func sizeOfInt32(p unsafe.Pointer, flags flags) int {
    17  	if p != nil {
    18  		if v := *(*int32)(p); v != 0 || flags.has(wantzero) {
    19  			return sizeOfVarint(flags.uint64(int64(v)))
    20  		}
    21  	}
    22  	return 0
    23  }
    24  
    25  func encodeInt32(b []byte, p unsafe.Pointer, flags flags) (int, error) {
    26  	if p != nil {
    27  		if v := *(*int32)(p); v != 0 || flags.has(wantzero) {
    28  			return encodeVarint(b, flags.uint64(int64(v)))
    29  		}
    30  	}
    31  	return 0, nil
    32  }
    33  
    34  func decodeInt32(b []byte, p unsafe.Pointer, flags flags) (int, error) {
    35  	u, n, err := decodeVarint(b)
    36  	v := flags.int64(u)
    37  	if v < math.MinInt32 || v > math.MaxInt32 {
    38  		return n, fmt.Errorf("integer overflow decoding %v into int32", v)
    39  	}
    40  	*(*int32)(p) = int32(v)
    41  	return n, err
    42  }