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add documentation

This commit is contained in:
Miek Gieben 2011-03-23 17:41:52 +01:00
parent 3af023bda9
commit ee88f57c1b
1 changed files with 27 additions and 6 deletions
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33
dns.go
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@ -46,8 +46,8 @@ func (e *Error) String() string {
}
// A Conn is the lowest primative in this DNS library
// A hold both the UDP and TCP connection, but only one
// can be active at any one time.
// A Conn holds both the UDP and TCP connection, but only one
// at any given time.
type Conn struct {
// The current UDP connection.
UDP *net.UDPConn
@ -61,17 +61,20 @@ type Conn struct {
// The remote port number of the connection.
Port int
// If TSIG is used, this holds all the information
// If TSIG is used, this holds all the information.
Tsig *Tsig
// Timeout in sec
// Timeout in sec before giving up on a connection.
Timeout int
// Number of attempts to try
// Number of attempts to try to Read/Write from/to a
// connection.
Attempts int
}
// Create a new buffer of the appropiate size.
// Create a new buffer of the appropiate size. With
// TCP the buffer is 64K, with UDP the returned buffer
// has a length of 4K bytes.
func (d *Conn) NewBuffer() []byte {
if d.TCP != nil {
b := make([]byte, MaxMsgSize)
@ -84,6 +87,8 @@ func (d *Conn) NewBuffer() []byte {
return nil
}
// ReadMsg reads a dns message m from d.
// Any errors of the underlaying Read call are returned.
func (d *Conn) ReadMsg(m *Msg) os.Error {
in := d.NewBuffer()
n, err := d.Read(in)
@ -98,6 +103,8 @@ func (d *Conn) ReadMsg(m *Msg) os.Error {
return nil
}
// WriteMsg writes dns message m to d.
// Any errors of the underlaying Write call are returned.
func (d *Conn) WriteMsg(m *Msg) os.Error {
out, ok := m.Pack()
if !ok {
@ -113,6 +120,9 @@ func (d *Conn) WriteMsg(m *Msg) os.Error {
return nil
}
// Read implements the standard Read interface:
// it reads from d. If there was an error
// reading that error is returned; otherwise err is nil.
func (d *Conn) Read(p []byte) (n int, err os.Error) {
if d.UDP != nil && d.TCP != nil {
return 0, &Error{Error: "UDP and TCP or both non-nil"}
@ -167,6 +177,9 @@ func (d *Conn) Read(p []byte) (n int, err os.Error) {
return
}
// Write implements the standard Write interface:
// It write data to d. If there was an error writing
// that error is returned; otherwise err is nil
func (d *Conn) Write(p []byte) (n int, err os.Error) {
if d.UDP != nil && d.TCP != nil {
return 0, &Error{Error: "UDP and TCP or both non-nil"}
@ -240,6 +253,8 @@ func (d *Conn) Write(p []byte) (n int, err os.Error) {
return
}
// Close closes the connection in d. Possible
// errors are returned in err; otherwise it is nil.
func (d *Conn) Close() (err os.Error) {
if d.UDP != nil && d.TCP != nil {
return &Error{Error: "UDP and TCP or both non-nil"}
@ -253,6 +268,8 @@ func (d *Conn) Close() (err os.Error) {
return
}
// SetTimeout sets the timeout of the socket
// that is contained in d.
func (d *Conn) SetTimeout() (err os.Error) {
var sec int64
if d.UDP != nil && d.TCP != nil {
@ -271,6 +288,10 @@ func (d *Conn) SetTimeout() (err os.Error) {
return
}
// Exchange combines a Write and a Read.
// First request is written to d and then it waits
// for a reply with Read.
// If nosend is true, the write is skipped.
func (d *Conn) Exchange(request []byte, nosend bool) (reply []byte, err os.Error) {
var n int
if !nosend {