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The extended socket class.
This class should be used instead of KSocket whenever the user needs fine-grained control over the socket being created. Unlike KSocket, which does everything at once, without much intervention, KExtendedSocket allows intervention at every step of the process and the setting of parameters.
This class allows for the creation of both server and client sockets. The only difference is that the passiveSocket flag must be passed either to the constructor or to setSocketFlags(). If passiveSocket is used, the class will enable functions listen() and accept() and related signals, and will also disable readBlock() and writeBlock().
To create a Unix socket, one would pass flag unixSocket to the constructor or setSocketFlags(). The hostname and service/port can be set to whatever is necessary. If no hostname is given, but a service/port is, the socket created will be implementation dependant (usually in /tmp). In any other case, the fields will be concatenated.
To create an Internet socket, inetSocket flag can be used. If, on the other hand a specific IP protocol is desired, ipv4Socket and/or ipv6Socket can be used.
Note that the socket type selection flags are cumulative. One could select Unix and Internet sockets by using unixSocket | inetSocket. Or, for instance, to make sure only IPv4 and IPv6 sockets are selected, even if future implementations support newer IP protocols, ipv4Socket | ipv6Socket is your guy.
| enum Flags { anySocket = 0x00, knownSocket = 0x01, unixSocket = knownSocket | 0x02, inetSocket = knownSocket | 0x04, ipv4Socket = inetSocket | 0x100, ipv6Socket = inetSocket | 0x200, passiveSocket = 0x1000, canonName = 0x2000, noResolve = 0x4000, streamSocket = 0x8000, datagramSocket = 0x10000, rawSocket = 0x20000, inputBufferedSocket = 0x200000, outputBufferedSocket = 0x400000, bufferedSocket = 0x600000 } | Flags |
flags that can be passed down to the member functions
| enum SockStatus { error = -1, nothing = 0, lookupInProgress = 50, lookupDone = 70, created = 100, bound = 140, connecting = 200, connected = 220, listening = 200, accepting = 220, closing = 350, done = 400 } | SockStatus |
status of the class The status are sequential. If a change to one status is requested, all the prior status will be passed and their actions, performed
| KExtendedSocket ()
| KExtendedSocket |
Creates an empty KExtendedSocket.
| KExtendedSocket (const QString& host, int port, int flags = 0)
| KExtendedSocket |
Creates a socket with the given hostname and port.
Parameters:
| host | the hostname |
| port | the port number |
| flags | flags |
| KExtendedSocket (const QString& host, const QString& service, int flags = 0)
| KExtendedSocket |
Creates a socket with the given hostname and service.
Parameters:
| host | the hostname |
| serv | the service |
| flags | flags |
| ~KExtendedSocket ()
| ~KExtendedSocket |
[virtual]
Destroys the socket, disconnecting if still connected and freeing any related resources still being kept.
| void reset ()
| reset |
Resets the socket, disconnecting if still connected and freeing any related resources still being kept.
| int socketStatus ()
| socketStatus |
[const]
Returns the class status.
Returns: the class status
See also: SockStatus
| int systemError ()
| systemError |
[const]
Returns the related system error code Except for IO_LookupError errors, these are codes found in errno
Returns: the system error code
| int setSocketFlags (int flags)
| setSocketFlags |
Sets the given flags.
Parameters:
| flags | the flags to be set |
Returns: the new flags status, or -1 if flags can no longer be set
| int socketFlags ()
| socketFlags |
[const]
Returns the current flags
Returns: the current flags
See also: Flags
| bool setHost (const QString& host)
| setHost |
Sets the hostname to the given value.
Parameters:
| host | the hostname |
Returns: true on success, false on error
| QString host ()
| host |
[const]
Returns the hostname.
Returns: the hostname or QString::null if no host has been set
| bool setPort (int port)
| setPort |
Sets the port/service.
Parameters:
| port | the port |
| bool setPort (const QString& service)
| setPort |
Sets the port/service.
Parameters:
| port | the port |
Returns: true if successful, false on error (e.g. connection already established)
| QString port ()
| port |
[const]
Returns the port/service. If it is a port, the string contains a number.
Returns: the port or QString::null if it has not been set.
| bool setAddress (const QString& host, int port)
| setAddress |
Sets the address where we will connect to.
Parameters:
| host | the hostname |
| port | port number |
Returns: true if successful, false on error (e.g. connection already established)
| bool setAddress (const QString& host, const QString& serv)
| setAddress |
Sets the address where we will connect to.
Parameters:
| host | the hostname |
| serv | the service |
Returns: true if successful, false on error (e.g. connection already established)
| bool setBindHost (const QString& host)
| setBindHost |
Sets the hostname to which we will bind locally before connecting.
Parameters:
| host | the hostname |
Returns: false if this is a passiveSocket, otherwise true.
| bool unsetBindHost ()
| unsetBindHost |
Unsets the bind hostname. That is, don't request a binding host.
Returns: true if successful, false on error (e.g. connection already established)
| QString bindHost ()
| bindHost |
[const]
Returns the hostname to which the socket will be/is bound.
Returns: the host or QString::null if it has not been set.
| bool setBindPort (int port)
| setBindPort |
Sets the port/service to which we will bind before connecting
Parameters:
| port | the port number |
Returns: true if successful, false on error (e.g. connection already established)
| bool setBindPort (const QString& service)
| setBindPort |
Sets the port/service to which we will bind before connecting.
Parameters:
| service | the port number or service name |
Returns: true if successful, false on error (e.g. connection already established)
| bool unsetBindPort ()
| unsetBindPort |
Unsets the bind port/service.
Returns: true if successful, false on error (e.g. connection already established)
| QString bindPort ()
| bindPort |
[const]
Returns the service to which the socket will be/is bound.
Returns: the host or QString::null if it has not been set.
| bool setBindAddress (const QString& host, int port)
| setBindAddress |
Sets both host and port to which we will bind the socket. Will return false if this is a passiveSocket.
Parameters:
| host | the hostname |
| port | the port number |
Returns: true if successful, false on error (e.g. connection already established)
| bool setBindAddress (const QString& host, const QString& service)
| setBindAddress |
Sets both host and service to which we will bind the socket. Will return false if this is a passiveSocket.
Parameters:
| host | the hostname |
| serv | the service |
Returns: true if successful, false on error (e.g. connection already established)
| bool unsetBindAddress ()
| unsetBindAddress |
Unsets the bind address for the socket. That means that we won't attempt to bind to an address before connecting.
Returns: true if successful, false on error (e.g. connection already established)
| bool setTimeout (int secs, int usecs = 0)
| setTimeout |
Sets the timeout value for the connection (if this is not passiveSocket) or acception (if it is). In the event the given function (connect or accept) returns due to time out, it's possible to call it again.
Setting the timeout to 0 disables the timeout feature.
Parameters:
| secs | the timeout length, in seconds |
| usecs | the timeout complement, in microseconds |
Returns: false if setting timeout makes no sense in the context.
| timeval timeout ()
| timeout |
[const]
Returns the timeout value for the connection.
Returns: the timeout value. 0 if there is no timeout.
| bool setBlockingMode (bool enable)
| setBlockingMode |
Sets/unsets blocking mode for the socket. When non-blocking mode is enabled, I/O operations might return error and set errno to EWOULDBLOCK. Also, it's not recommended to use this when using the class signals.
Parameters:
| enable | if true, set blocking mode. False, non-blocking mode. |
Returns: false on error.
| bool blockingMode ()
| blockingMode |
Returns the current blocking mode for this socket.
Returns: true if in blocking mode
| bool setAddressReusable (bool enable)
| setAddressReusable |
Sets/unsets address reusing flag for this socket.
This function returns true if the value was set correctly. That is NOT the result of the set.
Parameters:
| enable | if true, set address reusable |
Returns: true on success, false on failure. If the socket was not yet created, the value is only remembered. In this case the return value is always true.
| bool addressReusable ()
| addressReusable |
Returns whether this socket's address can be reused
Returns: true if the address can be reused
| bool setBufferSize (int rsize, int wsize = -2)
| setBufferSize |
[virtual]
Sets the buffer sizes for this socket.
This implementation allows any size for both parameters. The value given will be interpreted as the maximum size allowed for the buffers, after which the I/O functions will stop buffering. The value of -1 will be interpreted as "unlimited" size. The value of -2 means "no change".
Note: changing the buffer size to 0 for any buffer will cause the given buffer's to be discarded. Likewise, setting the size to a value less than the current size will cause the buffer to be shrunk to the wanted value, as if the data had been read.
Note 2: The closed() signal will only be emitted for a connection closed by the remote end if we are doing input buffering. That happens because if we aren't reading from the connection, we don't know when it closed.
Parameters:
| rsize | read buffer size |
| wsize | write buffer size |
Returns: true on success, false if this is not possible in this state (e.g. connection not established yet)
Reimplemented from KBufferedIO.
| const KSocketAddress * localAddress ()
| localAddress |
Returns the local socket address
Returns: the local socket address, can be 0 if the connection has not been established yet
| const KSocketAddress * peerAddress ()
| peerAddress |
Returns the peer socket address. Use KExtendedSocket::resolve() to resolve this to a human-readable hostname/service or port.
Returns: the peer address, can be 0 if the connection has not been established yet or the socket is passive
| inline int fd ()
| fd |
[const]
Returns the file descriptor
Returns: the file descriptor. -1 if there is no fd yet.
| int lookup ()
| lookup |
[virtual]
Performs lookup on the addresses we were given before.
This will perform lookups on the bind addresses if they were given.
Returns: 0 or an error. Do not rely on the values returned by lookup as of now. They are not specified.
| int startAsyncLookup ()
| startAsyncLookup |
[virtual]
Starts an asynchronous lookup for the addresses given.
When the lookup is done, the lookupReady signal will be emitted.
Note that, depending on the parameters for the lookup, this function might know the results without the need for blocking or queueing an asynchronous lookup. That means that the lookupReady signal might be emitted by this function, so your code should be prepared for that.
One such case is when noResolve flag is set. If this function is able to determine the results without queueing and the lookup failed, this function will return -1.
Returns: 0 on success or -1 on error. Note that returning 0 means that either we are in the process of doing lookup or that it has finished already.
| void cancelAsyncLookup ()
| cancelAsyncLookup |
[virtual]
Cancels any on-going asynchronous lookups
| int listen (int N = 5)
| listen |
[virtual]
Place the socket in listen mode. The parameters are the same as for the system listen() call.
Parameters:
| N | the queue length for pending connections |
Returns: 0 on success, -1 on system error (errno available) and -2 if this is not a passiveSocket.
| int accept (KExtendedSocket *&sock)
| accept |
[virtual]
Accepts an incoming connection from the socket. If this socket is in blocking mode, this function will block until a connection is received. Otherwise, it might return with error. The sock parameter will be initialised with the newly created socket.
Upon successful acception (i.e., this function returns 0), the newly created socket will be already connected. The socket will be unbuffered and readyRead() and readyWrite() signals will be disabled.
Parameters:
| sock | a pointer to an KExtendedSocket variable |
Returns: 0 on success, -1 on system error (errno set) and -2 if this is not a passiveSocket and -3 if this took too long (time out)
| int connect ()
| connect |
[virtual]
Attempts to connect to the remote host. After successful connection (return value 0), the socket will be ready for I/O operations. Note, however, that not all signals may be enabled for emission by this socket:
Note that, in general, functions inherited/overriden from KBufferedIO will only work on buffered sockets, like bytesAvailable and bytesToWrite.
Returns: The return values are:
| int startAsyncConnect ()
| startAsyncConnect |
[virtual]
Starts an asynchronous connect. This works exactly the same as #connect, except that the connection result won't be returned.
Note that those signals might be emitted before this function returns, so your code should be prepared for that condition.
Returns: 0 on successful queueing of the connect or -1 on error. If this function returns 0, then the connectionSuccess() or the connectionFailed() signals will be emitted.
| void cancelAsyncConnect ()
| cancelAsyncConnect |
[virtual]
Cancels any on-going asynchronous connection attempt.
| bool open (int mode = IO_Raw | IO_ReadWrite)
| open |
[virtual]
Implementation of QIODevice::open() pure virtual function. This depends on the target host address already being there. If this is a passiveSocket, this is identical to call listen(); else, if this is not a passiveSocket and no connection attempt is in progress, this is like connect(). If one is in progress, this function will fail.
Parameters:
| mode | the open mode. Must be IO_Raw | IO_ReadWrite |
Returns: true if successful, false when an error occurred or the most was not correct
| void close ()
| close |
[virtual]
Closes the socket. If we have data still in the write buffer yet to be sent, the socket won't be closed right now. It'll be closed after we managed to send everything out. If you want to close the socket now, you may want to call flush() first, and then closeNow().
| void closeNow ()
| closeNow |
[virtual]
Closes the socket now, discarding the contents of the write buffer, if any. The read buffer's contents are kept until they are emptied by read operations or the class is destroyed.
Reimplemented from KBufferedIO.
| void release ()
| release |
[virtual]
Releases the socket and anything we have holding on it. The class cannot be used anymore. In other words, this is just like closeNow(), but it does not actually close the socket.
This is useful if you just want to connect and don't need the rest of the class.
Note that the buffers' contents will be discarded.
Use of this method is discouraged, because the socket created might be such that normal library routines can't handle (read, write, close, etc.)
| void flush ()
| flush |
[virtual]
Flushes the socket buffer. You need not call this method during normal operation as we will try and send everything as soon as possible. However, if you want to make sure that data in the buffer is being sent at this moment, you can call this function. It will try to send as much data as possible, but it will stop as soon as the kernel cannot receive any more data, and would possibly block.
By repeatedly calling this function, the behaviour will be like that of a blocking socket. Indeed, if this function is called with the kernel not ready to receive data, it will block, unless this is a non-blocking socket.
This function does not touch the read buffer. You can empty it by calling readBlock() with a null destination buffer.
| inline Q_ULONG size ()
| size |
[const virtual]
Returns length of this socket. This call is not supported on sockets.
Returns: the length of this socket, or 0 if unsupported
| inline Q_ULONG at ()
| at |
[const virtual]
Returns relative position from start. This call is not supported on sockets.
Returns: the relative position from the start, or 0 if unsupported
| inline bool at (int i)
| at |
[virtual]
Returns true if we are at position. This is not supported on sockets.
Parameters:
| i | the position to check |
Returns: true if we art at the given position, or always true if unsupported.
| inline bool atEnd ()
| atEnd |
[const virtual]
Returns true if we are at the end. This is not supported on sockets, but we always are at the end in a socket...
Returns: true if we are at the end. Always false if unsupported.
| Q_LONG readBlock (char *data, Q_ULONG maxlen)
| readBlock |
[virtual]
Reads a block of data from the socket.
If the socket is not buffered, this function will simply call the underlying read method. This function will block if the socket is not on non-blocking mode (see setBlockingMode) and there is not enough data to be read in the Operating System yet. If we are in non-blocking operation, the call will fail in this case.
However, if we are buffering, this function will instead read from the buffer while there is available data. This function will never block in buffering mode, which means that if you try to read while the buffers are empty, this function will always return -1 and set the system error to EWOULDBLOCK (aka EAGAIN), so as to mimic non-blocking operation.
Parameters:
| data | where we will write the read data to |
| maxlen | maximum length of data to be read |
Returns: the number of bytes effectively read, or a negative number in case
or an error. If the data param is not null, then this is also the number
of bytes copied into that buffer. If the return value is different than
maxlen, then this function encountered a situation in which no more
bytes were available. Subsequent calls might cause this function to one
of these behaviours:
| Q_LONG writeBlock (const char *data, Q_ULONG len)
| writeBlock |
[virtual]
Writes a block of data to the socket.
If the socket is not buffered, this function will simply call the underlying write method. This means that the function might block if that method blocks as well. That situation is possible if we are not in non-blocking mode and the operating system buffers are full for this socket. If we are in non-blocking mode and the operating system buffers are full, this function will return -1 and the system error will be set to EWOULDBLOCK.
If we are buffering, this function will simply transfer the data into the write buffer. This function will then always succeed, as long as there is enough room in the buffer. If the buffer size was limited and that limit is reached, this function will copy no more bytes than that limit. Trying to write with a full buffer will return -1 and set system error to EWOULDBLOCK.
Parameters:
| data | the data to write |
| len | the length of data to write |
Returns: the number of bytes written from data buffer.
The return value might be less than len if the output buffers cannot
accommodate that many bytes and -1 in the case of an errro.
| int peekBlock (char *data, uint maxlen)
| peekBlock |
[virtual]
Peeks at a block of data from the socket.
This is exactly like read, except that the data won't be flushed from the read buffer.
If this socket is not buffered, this function will always return with 0 bytes copied.
Parameters:
| data | where to store the data |
| maxlen | how many bytes to copy, at most |
Returns: the number of bytes copied. 0 does not mean end-of-file condition.
Reimplemented from KBufferedIO.
| int unreadBlock (const char *data, uint len)
| unreadBlock |
[virtual]
Reimplementation of unreadBlock() method. This is so because unreading in sockets doesn't make sense, so this function will always return -1 (error) and set the system error to ENOSYS.
Returns: always -1 (error)
Reimplemented from KBufferedIO.
| int bytesAvailable ()
| bytesAvailable |
[const virtual]
Returns the number of available bytes yet to be read via readBlock and family of functions.
Note: as of now, this only works on input-buffered sockets. This will change in the future
Returns: The number of available bytes, or -1 on error or -2 if this call is invalid in the current state.
Reimplemented from KBufferedIO.
| int waitForMore (int msec)
| waitForMore |
[virtual]
Waits msec milliseconds for more data to be available (use 0 to
wait forever). The return value is the amount of data available for
read in the read buffer.
Parameters:
| msec | milliseconds to wait |
Returns: -1 in case of system error and -2 in case of invalid socket state
Reimplemented from KBufferedIO.
| int getch ()
| getch |
[virtual]
Gets a single character (unsigned char) from the stream.
Returns: the value of the character. Negative if there was an error.
| int putch (int ch)
| putch |
[virtual]
Writes a single character (unsigned char) to the stream. All other bits will be ignored.
Parameters:
| ch | character to write, converted to char |
| int ungetch (int)
| ungetch |
[virtual]
Unreads one character from the stream. This is not possible on sockets.
Returns: always returns -1 on sockets.
| void enableRead (bool enable)
| enableRead |
[virtual]
Toggles the emission of the readyRead signal.
Note that this signal is emitted every time more data is available to be read, so you might get flooded with it being emitted every time, when in non-buffered mode. However, in buffered mode, this signal will be emitted only when there is data coming in from the wire. By default, this flag is set to false, i.e., signal not being emitted.
Parameters:
| enable | if true, the signal will be emitted |
Reimplemented from KAsyncIO.
| void enableWrite (bool enable)
| enableWrite |
[virtual]
Toggles the emission of the readyWrite signal.
Note that this signal is emitted only when the OS is ready to receive more data, which means that the write buffer is empty. And when that is reached, this signal will possibly be emitted on every loop, so you might want to disable it. By default, this flag is set to false.
Parameters:
| enable | if true, the signal will be emitted |
Reimplemented from KAsyncIO.
| void lookupFinished (int count)
| lookupFinished |
[signal]
This signal is emitted whenever an asynchronous lookup process is done.
The parameter count tells
Parameters:
| count | the number of results |
| void connectionSuccess ()
| connectionSuccess |
[signal]
This signal is emitted whenever we connected asynchronously to a host.
| void connectionFailed (int error)
| connectionFailed |
[signal]
This signal is emitted whenever our asynchronous connection attempt failed to all hosts listed.
Parameters:
| error | the errno code of the last connection attempt |
| void readyAccept ()
| readyAccept |
[signal]
This signal is emitted whenever this socket is ready to accept another socket.
See also: accept()
| int sockfd | sockfd |
[protected]
| void socketActivityRead ()
| socketActivityRead |
[protected slots slot]
| void socketActivityWrite ()
| socketActivityWrite |
[protected slots slot]
| void dnsResultsReady ()
| dnsResultsReady |
[protected slots slot]
| void startAsyncConnectSlot ()
| startAsyncConnectSlot |
[protected slots slot]
| void connectionEvent ()
| connectionEvent |
[protected slots slot]
| QSocketNotifier * readNotifier ()
| readNotifier |
[protected]
| QSocketNotifier * writeNotifier ()
| writeNotifier |
[protected]
| void setError (int errorkind, int error)
| setError |
[protected]
Sets the error code
| inline void cleanError ()
| cleanError |
[protected]
| void setSocketStatus (int status)
| setSocketStatus |
[protected]
Sets the socket status. For derived classes only.
| int resolve (sockaddr* sock, ksocklen_t len, QString& host, QString& port, int flags = 0)
| resolve |
[static]
Performs resolution on the given socket address.
That is, tries to resolve the raw form of the socket address into a textual representation.
Parameters:
| sockaddr | the socket address |
| host | where the hostname will be written |
| port | where the service-port will be written |
| flags | the same flags as getnameinfo() |
Returns: 0 on success, nonzero otherwise.
| int resolve (KSocketAddress* sock, QString& host, QString& port, int flags = 0)
| resolve |
[static]
Performs resolution on the given socket address.
That is, tries to resolve the raw form of the socket address into a textual representation.
Parameters:
| sockaddr | the socket address |
| host | where the hostname will be written |
| port | where the service-port will be written |
| flags | the same flags as getnameinfo() |
Returns: 0 on success, nonzero otherwise.
| QPtrList<KAddressInfo> lookup (const QString& host, const QString& port, int flags = 0, int *error = 0)
| lookup |
[static]
Performs lookup on the given hostname/port combination and returns a list of matching addresses. The error code can be transformed into string by KExtendedSocket::strError() with code of IO_LookupError.
IMPORTANT: the result values of the QPtrList must be deleted after use. So, if you don't copy the KAddressInfo objects, the best way to assure that is to call setAutoDelete(true) on the list right after this function returns. If you do copy the results out, you must assure that the objects get deleted when they are not needed any more.
Parameters:
| host | the hostname to look up |
| port | the port/service to look up |
| flags | flags to be used when looking up, Flags |
| error | pointer to a variable holding the error code |
Returns: a list of KAddressInfos
| KSocketAddress * localAddress (int fd)
| localAddress |
[static]
Returns the local socket address Remember to delete the returned object when it is no longer needed.
Parameters:
| fd | the file descriptor |
Returns: the local socket address or 0 if an error occurred. Delete after use.
| KSocketAddress * peerAddress (int fd)
| peerAddress |
[static]
Returns the peer socket address. Use KExtendedSocket::resolve() to resolve this to a human-readable hostname/service or port. Remember to delete the returned object when it is no longer needed.
Parameters:
| fd | the file descriptor |
Returns: the peer socket address or 0 if an error occurred. Delete after use.
| QString strError (int code, int syserr)
| strError |
[static]
Returns the representing text of this error code
Parameters:
| code | the error code, as seen in status() |
| syserr | the system error, as from systemError() |
Returns: the text for the given error code
| bool setAddressReusable (int fd, bool enable)
| setAddressReusable |
[static]
Sets/unsets address reusing flag for this socket.
This function returns true if the value was set correctly. That is NOT the result of the set.
Parameters:
| fd | the file descriptor |
| enable | if true, set address reusable |
Returns: true on success, false on failure.
| void virtual_hook ( int id, void* data )
| virtual_hook |
[protected virtual]
Reimplemented from KBufferedIO.