utils

Documentation

Index

• Constants
• func GetIPFromAddr(addr net.Addr) (ip net.IP)
• func GetMsgBuf(size int) []byte
• func GetMsgBufFor(m *dns.Msg) ([]byte, error)
• func GetTimer(t time.Duration) *time.Timer
• func ParseAddr(addr string) (protocol, host string)
• func ReadMsgFromTCP(c io.Reader) (m *dns.Msg, n int, err error)
• func ReadMsgFromUDP(c io.Reader, bufSize int) (m *dns.Msg, n int, err error)
• func ReadUDPMsgFrom(c net.PacketConn, bufSize int) (m *dns.Msg, from net.Addr, n int, err error)
• func ReleaseMsgBuf(buf []byte)
• func ReleaseTimer(timer *time.Timer)
• func ResetAndDrainTimer(timer *time.Timer, d time.Duration)
• func TryAddPort(host string, port uint16) string
• func WriteMsgToTCP(c io.Writer, m *dns.Msg) (n int, err error)
• func WriteMsgToUDP(c io.Writer, m *dns.Msg) (n int, err error)
• func WriteRawMsgToTCP(c io.Writer, b []byte) (n int, err error)
• func WriteRawMsgToUDP(c io.Writer, b []byte) (n int, err error)
• func WriteUDPMsgTo(m *dns.Msg, c net.PacketConn, to net.Addr) (n int, err error)
• type Allocator
  • func NewAllocator() *Allocator
  • func (alloc *Allocator) Get(size int) []byte
  • func (alloc *Allocator) Put(buf []byte)
• type LoadOnceCache
  • func NewCache() *LoadOnceCache
  • func (c *LoadOnceCache) Load(key string) (interface{}, bool)
  • func (c *LoadOnceCache) LoadFromCacheOrRawDisk(file string) (interface{}, []byte, error)
  • func (c *LoadOnceCache) Put(key string, data interface{}, ttl time.Duration)
  • func (c *LoadOnceCache) Remove(key string)

Constants

const (
	IPv4UdpMaxPayload = 1472 // MTU 1500 - 20 IPv4 header - 8 udp header
	IPv6UdpMaxPayload = 1452 // MTU 1500 - 40 IPv6 header - 8 udp header
)

Functions

func GetIPFromAddr

func GetIPFromAddr(addr net.Addr) (ip net.IP)

GetIPFromAddr returns net.IP from net.Addr. Will return nil if no ip address can be parsed.

func GetMsgBuf

func GetMsgBuf(size int) []byte

func GetMsgBufFor

func GetMsgBufFor(m *dns.Msg) ([]byte, error)

func GetTimer

func GetTimer(t time.Duration) *time.Timer

func ParseAddr

func ParseAddr(addr string) (protocol, host string)

ParseAddr splits addr to protocol and host.

func ReadMsgFromTCP

func ReadMsgFromTCP(c io.Reader) (m *dns.Msg, n int, err error)

ReadMsgFromTCP reads msg from a tcp connection. n represents how many bytes are read from c.

func ReadMsgFromUDP

func ReadMsgFromUDP(c io.Reader, bufSize int) (m *dns.Msg, n int, err error)

func ReadUDPMsgFrom

func ReadUDPMsgFrom(c net.PacketConn, bufSize int) (m *dns.Msg, from net.Addr, n int, err error)

func ReleaseMsgBuf

func ReleaseMsgBuf(buf []byte)

func ReleaseTimer

func ReleaseTimer(timer *time.Timer)

func ResetAndDrainTimer

func ResetAndDrainTimer(timer *time.Timer, d time.Duration)

func TryAddPort

func TryAddPort(host string, port uint16) string

TryAddPort add port to host if host does not has an port suffix.

func WriteMsgToTCP

func WriteMsgToTCP(c io.Writer, m *dns.Msg) (n int, err error)

WriteMsgToTCP writes m to c. n represents how many bytes are wrote to c. This includes 2 bytes tcp header.

func WriteMsgToUDP

func WriteMsgToUDP(c io.Writer, m *dns.Msg) (n int, err error)

func WriteRawMsgToTCP

func WriteRawMsgToTCP(c io.Writer, b []byte) (n int, err error)

WriteRawMsgToTCP writes b to c. n represents how many bytes are wrote to c. This includes 2 bytes tcp header.

func WriteRawMsgToUDP

func WriteRawMsgToUDP(c io.Writer, b []byte) (n int, err error)

func WriteUDPMsgTo

func WriteUDPMsgTo(m *dns.Msg, c net.PacketConn, to net.Addr) (n int, err error)

Types

type Allocator

type Allocator struct {
	// contains filtered or unexported fields
}

func NewAllocator

func NewAllocator() *Allocator

NewAllocator initiates a []byte allocator for dns.Msg less than 65536 bytes, the waste(memory fragmentation) of space allocation is guaranteed to be no more than 50%.

func (*Allocator) Get

func (alloc *Allocator) Get(size int) []byte

Get a []byte from pool with most appropriate cap

func (*Allocator) Put

func (alloc *Allocator) Put(buf []byte)

Put returns a []byte to pool for future use, which the cap must be exactly 2^n

type LoadOnceCache

type LoadOnceCache struct {
	// contains filtered or unexported fields
}

func NewCache

func NewCache() *LoadOnceCache

func (*LoadOnceCache) Load

func (c *LoadOnceCache) Load(key string) (interface{}, bool)

func (*LoadOnceCache) LoadFromCacheOrRawDisk

func (c *LoadOnceCache) LoadFromCacheOrRawDisk(file string) (interface{}, []byte, error)

func (*LoadOnceCache) Put

func (c *LoadOnceCache) Put(key string, data interface{}, ttl time.Duration)

func (*LoadOnceCache) Remove

func (c *LoadOnceCache) Remove(key string)