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

     1  package proto
     2  
     3  import (
     4  	"io"
     5  	"unsafe"
     6  )
     7  
     8  var stringCodec = codec{
     9  	wire:   varlen,
    10  	size:   sizeOfString,
    11  	encode: encodeString,
    12  	decode: decodeString,
    13  }
    14  
    15  func sizeOfString(p unsafe.Pointer, flags flags) int {
    16  	if p != nil {
    17  		if v := *(*string)(p); v != "" || flags.has(wantzero) {
    18  			return sizeOfVarlen(len(v))
    19  		}
    20  	}
    21  	return 0
    22  }
    23  
    24  func encodeString(b []byte, p unsafe.Pointer, flags flags) (int, error) {
    25  	if p != nil {
    26  		if v := *(*string)(p); v != "" || flags.has(wantzero) {
    27  			n, err := encodeVarint(b, uint64(len(v)))
    28  			if err != nil {
    29  				return n, err
    30  			}
    31  			c := copy(b[n:], v)
    32  			n += c
    33  			if c < len(v) {
    34  				err = io.ErrShortBuffer
    35  			}
    36  			return n, err
    37  		}
    38  	}
    39  	return 0, nil
    40  }
    41  
    42  func decodeString(b []byte, p unsafe.Pointer, _ flags) (int, error) {
    43  	v, n, err := decodeVarlen(b)
    44  	*(*string)(p) = string(v)
    45  	return n, err
    46  }