diff options
Diffstat (limited to 'src/net/ip.go')
| -rw-r--r-- | src/net/ip.go | 40 |
1 files changed, 36 insertions, 4 deletions
diff --git a/src/net/ip.go b/src/net/ip.go index 6b7ba4c23e..a94ff73130 100644 --- a/src/net/ip.go +++ b/src/net/ip.go @@ -260,6 +260,25 @@ func (ip IP) Mask(mask IPMask) IP { return out } +// ubtoa encodes the string form of the integer v to dst[start:] and +// returns the number of bytes written to dst. The caller must ensure +// that dst has sufficient length. +func ubtoa(dst []byte, start int, v byte) int { + if v < 10 { + dst[start] = byte(v + '0') + return 1 + } else if v < 100 { + dst[start+1] = byte(v%10 + '0') + dst[start] = byte(v/10 + '0') + return 2 + } + + dst[start+2] = byte(v%10 + '0') + dst[start+1] = byte((v/10)%10 + '0') + dst[start] = byte(v/100 + '0') + return 3 +} + // String returns the string form of the IP address ip. // It returns one of 4 forms: // - "<nil>", if ip has length 0 @@ -275,10 +294,23 @@ func (ip IP) String() string { // If IPv4, use dotted notation. if p4 := p.To4(); len(p4) == IPv4len { - return uitoa(uint(p4[0])) + "." + - uitoa(uint(p4[1])) + "." + - uitoa(uint(p4[2])) + "." + - uitoa(uint(p4[3])) + const maxIPv4StringLen = len("255.255.255.255") + b := make([]byte, maxIPv4StringLen) + + n := ubtoa(b, 0, p4[0]) + b[n] = '.' + n++ + + n += ubtoa(b, n, p4[1]) + b[n] = '.' + n++ + + n += ubtoa(b, n, p4[2]) + b[n] = '.' + n++ + + n += ubtoa(b, n, p4[3]) + return string(b[:n]) } if len(p) != IPv6len { return "?" + hexString(ip) |