BNetEndpoint¶
Constructor and Destructor¶
BNetEndpoint()
BNetEndpoint::BNetEndpoint(int protocol = SOCK_STREAM)
BNetEndpoint::BNetEndpoint(const BNetEndpoint &from)
BNetEndpoint::BNetEndpoint(BMessage *archive)
Creates a BNetEndpoint representing a network connection endpoint
on the local system. After construction, you must call
InitCheck()
to ensure that no errors occurred
during setup.
The protocol argument lets you specify whether the
BNetEndpoint will use a stream socket
(SOCK_STREAM
) or a datagram socket
(SOCK_DGRAM
).
By default, I/O is blocking and address reusing is off. You can change
these by calling SetNonBlocking()
and
SetReuseAddr()
.
~BNetEndpoint()
virtual BNetEndpoint::~BNetEndpoint()
A typical destructor.
Member Functions¶
Bind()
virtual status_t BNetEndpoint::Bind(const BNetAddress &address)
virtual status_t BNetEndpoint::Bind(int port = 0)
Binds the BNetEndpoint to a specific local address. That address
can be specified by using a BNetAddress
or a simple
port number. This selects the port that will handle the local end
of the connection.
If your BNetEndpoint is using a stream protocol and is going to be listening for connections, you must call Bind().
If your stream BNetEndpoint is a client, it doesn’t have to call Bind() but you can if you want to. There aren’t any significant benefits to doing so, however.
A stream accept BNetEndpoints must not be bound.
Datagram BNetEndpoints that are going to receive data must be bound; datagram BNetEndpoints that will only be sending data don’t have to be. However, if an endpoint will both send and receive, it must be bound.
If you don’t specify an address or port number, or
specify a port number of 0, Bind() will bind the
BNetEndpoint to a random local port. You can determine which one
by calling LocalAddr()
.
The only way to unbind a BNetEndpoint from an address or port is to close the endpoint.
Return Code |
Description |
---|---|
|
The address was successfully bound to. |
|
An error occurred. |
Close()
virtual void BNetEndpoint::Close()
Closes the connection, if there is one. If there’s unread data buffered up, it’s disposed of.
Connect()
virtual status_t BNetEndpoint::Connect(const BNetAddress &address)
virtual status_t BNetEndpoint::Connect(const char *address, unsigned short port)
Opens a connection to the specified remote system. The system’s address can be specified by either using a BNetAddress or by specifying the IP address or domain name and port number. For example, to connect to the Megaburger, Inc. web server, your software would call:
status_t err = myEndpoint->Connect("www.megaburger.com", 80);
if (err != B_OK) {
/* error occurred */
}
else {
/* all is well, connection is open */
}
Return Code |
Description |
---|---|
|
The connection was opened. |
|
An error occurred. |
Error(), ErrorStr()
int BNetEndpoint::Error() const
char *BNetEndpoint::ErrorStr() const
Error() returns the integer error code for the last send or
receive error. If you receive a B_ERROR
result from a
send or receive function, you can find out the specific error using this
function.
ErrorStr() returns a pointer to a text string describing the error; this string isn’t yours, so don’t try to free() it.
InitCheck()
status_t BNetEndpoint::InitCheck() const
Returns a status_t indicating whether or not the object was successfully instantiated.
Return Code |
Description |
---|---|
|
The BNetEndpoint was constructed without error. |
|
An error occurred during construction. |
IsDataPending()
virtual bool BNetEndpoint::IsDataPending(bigtime_t timeout = 0)
Returns true if there’s data waiting to be received, otherwise returns false. If you specify a timeout other than 0, the function will block until either data is available or the timeout period elapses.
Listen(), Accept()
virtual status_t BNetEndpoint::Listen(int backlog = 5)
virtual BNetEndpoint *BNetEndpoint::Accept(int32 timeout = -1)
Listen() tells the BNetEndpoint to begin listening for incoming connection attempts on its local port. These attempts are queued; up to backlog attempts can be in the queue at any time. If more attempts are backlogged than that, the later attempts will be rejected until there’s room in the queue.
You can accept an incoming connection attempt by calling Accept(). If there are no connection attempts queued up, this function returns NULL. If there are connection attempts in the queue, a new BNetEndpoint object is created with the connection between your local port and the remote system opened, and that BNetEndpoint is returned to you.
The new connection is yours to do with as you please. When you’re finished with the connection, you must delete the returned BNetEndpoint. Typically your listener thread will look something like this:
long MyListener(void* data) {
BNetEndpoint endpoint;
if (endpoint.InitCheck() < B_OK) {
return -1;
}
/* bind to the desired port */
endpoint.Bind(portNumber);
/* listen for connections */
endpoint.Listen();
while (keepListening) {
BNetEndpoint* connect = NULL;
connect = endpoint.Accept();
if (connect) {
/* call a function do the work */
handle_connection(connect, data);
delete connect;
}
}
endpoint.Close();
}
Return Code |
Description |
---|---|
|
Success. |
|
Failure. |
LocalAddr(), RemoteAddr()
const BNetAddress &BNetEndpoint::LocalAddr()
const BNetAddress &BNetEndpoint::RemoteAddr()
These functions return a BNetAddress
representing the local or
remote system on the connection. LocalAddr() returns the address
of the local machine, and RemoteAddr() (amazingly enough)
returns the address of the remote system.
If there isn’t a remote connection, RemoteAddr() will return a
BNetAddress
indicating an IP address of 0.0.0.0.
Receive(), ReceiveFrom()
virtual int32 BNetEndpoint::Receive(const void *buffer, size_t size, int flags = 0)
virtual int32 BNetEndpoint::Receive(BNetBuffer &buffer, size_t size, int flags = 0)
virtual int32 BNetEndpoint::ReceiveFrom(const void *buffer, size_t size, const BNetAddress &from, int flags = 0)
virtual int32 BNetEndpoint::ReceiveFrom(BNetBuffer &buffer, size_t size, const BNetAddress &from, int flags = 0)
Receive() receives a buffer of data from the remote end of the
connection. If there’s no connection established, B_ERROR
is returned immediately. Up to size bytes of data are received.
ReceiveFrom() receives the buffer from the remote system
specified by the from BNetAddress
. ReceiveFrom()
only works if the connection is using a datagram protocol.
The first form of each function function sends an arbitrary buffer of the
specified size, and the second form sends the contents of a
BNetBuffer
. When using a BNetBuffer
, incoming
data is appended to the end of the buffer, so you can use the same buffer
in a loop to buffer incoming data in chunks until the desired number of
bytes have been read.
The flags argument, which is passed on to the socket.h
recv()
or recvfrom()
function, is currently unused
and must be 0.
When you call these functions in blocking mode (which is the default), they
block until there’s data available to receive or a timeout occurs. The
timeout period is set by calling SetTimeout()
.
You can turn on or off blocking by calling
SetNonBlocking()
. If you’re in nonblocking mode
and there’s no data waiting, these functions return 0 immediately,
indicating that there’s no data.
These functions return the number of bytes actually received, or -1 if an
error occurred. You can call Error()
to get the
specific error that occurred.
Send(), SendTo()
virtual int32 BNetEndpoint::Send(const void *buffer, size_t size, int flags = 0)
virtual int32 BNetEndpoint::Send(BNetBuffer &buffer, int flags = 0)
virtual int32 BNetEndpoint::SendTo(const void *buffer, size_t size, const BNetAddress &to, int flags = 0)
virtual int32 BNetEndpoint::SendTo(BNetBuffer &buffer, const BNetAddress &to, int flags = 0)
Send() sends a buffer of data to the remote end of the
connection. If there’s no connection established, B_ERROR
is returned immediately. In addition, if the BNetEndpoint is
configured to use a datagram protocol, this function fails unless
Connect()
has been called, since that function
caches the destination address.
SendTo() sends the buffer to the remote system specified by the
to BNetAddress
. SendTo() only works if the
connection is using a datagram protocol.
The first form of each function function sends an arbitrary buffer of the
specified size, and the second form sends the contents of a
BNetBuffer
.
The flags argument, which is passed on to the the socket.h
send()
or sendto()
function, is currently unused
and must be 0.
These functions return the number of bytes actually sent, or -1 if an error
occurred. You can call Error()
to get the
specific error that occurred.
SetOption(), SetNonBlocking(), SetReuseAddr()
int BNetEndpoint::SetOption(int32 option, int32 level, const void *data, unsigned int dataSize)
int BNetEndpoint::SetNonBlocking(bool enable = true)
int BNetEndpoint::SetReuseAddr(bool enable = true)
SetOption() lets you set any option for the BNetEndpoint. This provides access to the setsockopt() function of the underlying socket.
SetNonBlocking() controls whether I/O should block or not. If enable is true, the connection will be nonblocking. If enable is false, the connection will block on I/O calls until the transmission is completed.
SetReuseAddr() controls whether addresses should be reused or not. If enable is true, addresses will be reused. If enable is false, the connection won’t reuse addresses.
These functions return 0 if successful; otherwise they return -1.
SetProtocol()
status_t BNetEndpoint::SetProtocol(int protocol)
Sets the protocol type for the connection. Possible values for the protocol
argument are SOCK_STREAM
(to use the stream protocol) or
SOCK_DGRAM
(for datagram protocol).
Return Code |
Description |
---|---|
|
The protocol was set successfully. |
|
An error occurred setting the protocol. |
SetTimeout()
void BNetEndpoint::SetTimeout(bigtime_t timeout)
Sets the timeout for calls to Receive()
and
ReceiveFrom()
. If blocking I/O is in use, and
timeout microseconds pass, the function will abort with an error.
By default, there’s no timeout. You can specify that you want no timeout by
specifying -1.
Socket()
int BNetEndpoint::Socket() const
Returns the actual socket used by the BNetEndpoint for data communications.
Operators¶
BNetEndpoint &operator=(const BNetEndpoint &from)
Copies the BNetEndpoint specified by from into the left-side object, thereby duplicating that object. If from is connected, the left-side object will duplicate and open the same connection.