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/* +------------------------------------+
* | Inspire Internet Relay Chat Daemon |
* +------------------------------------+
*
* InspIRCd: (C) 2002-2007 InspIRCd Development Team
* See: http://www.inspircd.org/wiki/index.php/Credits
*
* This program is free but copyrighted software; see
* the file COPYING for details.
*
* ---------------------------------------------------
*/
#ifndef __SOCKETENGINE__
#define __SOCKETENGINE__
#include <vector>
#include <string>
#include <map>
#include "inspircd_config.h"
#include "base.h"
/** Types of event an EventHandler may receive.
* EVENT_READ is a readable file descriptor,
* and EVENT_WRITE is a writeable file descriptor.
* EVENT_ERROR can always occur, and indicates
* a write error or read error on the socket,
* e.g. EOF condition or broken pipe.
*/
enum EventType
{
/** Read event */
EVENT_READ = 0,
/** Write event */
EVENT_WRITE = 1,
/** Error event */
EVENT_ERROR = 2
};
class InspIRCd;
/** This class is a basic I/O handler class.
* Any object which wishes to receive basic I/O events
* from the socketengine must derive from this class and
* implement the HandleEvent() method. The derived class
* must then be added to SocketEngine using the method
* SocketEngine::AddFd(), after which point the derived
* class will receive events to its HandleEvent() method.
* The derived class should also implement one of Readable()
* and Writeable(). In the current implementation, only
* Readable() is used. If this returns true, the socketengine
* inserts a readable socket. If it is false, the socketengine
* inserts a writeable socket. The derived class should never
* change the value this function returns without first
* deleting the socket from the socket engine. The only
* requirement beyond this for an event handler is that it
* must have a file descriptor. What this file descriptor
* is actually attached to is completely up to you.
*/
class CoreExport EventHandler : public Extensible
{
protected:
/** File descriptor.
* All events which can be handled
* must have a file descriptor.
* This allows you to add events for
* sockets, fifo's, pipes, and various
* other forms of IPC.
*/
int fd;
public:
/** Get the current file descriptor
* @return The file descriptor of this handler
*/
int GetFd();
/** Set a new file desciptor
* @param FD The new file descriptor. Do not
* call this method without first deleting the
* object from the SocketEngine if you have
* added it to a SocketEngine instance.
*/
void SetFd(int FD);
/** Constructor
*/
EventHandler() {}
/** Destructor
*/
virtual ~EventHandler() {}
/** Override this function to indicate readability.
* @return This should return true if the function
* wishes to receive EVENT_READ events. Do not change
* what this function returns while the event handler
* is still added to a SocketEngine instance!
* If this function is unimplemented, the base class
* will return true.
*
* NOTE: You cannot set both Readable() and
* Writeable() to true. If you wish to receive
* a write event for your object, you must call
* SocketEngine::WantWrite() instead. This will
* trigger your objects next EVENT_WRITE type event.
*/
virtual bool Readable();
/** Override this function to indicate writeability.
* @return This should return true if the function
* wishes to receive EVENT_WRITE events. Do not change
* what this function returns while the event handler
* is still added to a SocketEngine instance!
* If this function is unimplemented, the base class
* will return false.
*
* NOTE: You cannot set both Readable() and
* Writeable() to true. If you wish to receive
* a write event for your object, you must call
* SocketEngine::WantWrite() instead. This will
* trigger your objects next EVENT_WRITE type event.
*/
virtual bool Writeable();
/** Process an I/O event.
* You MUST implement this function in your derived
* class, and it will be called whenever read or write
* events are received, depending on what your functions
* Readable() and Writeable() returns and wether you
* previously made a call to SocketEngine::WantWrite().
* @param et either one of EVENT_READ for read events,
* and EVENT_WRITE for write events.
*/
virtual void HandleEvent(EventType et, int errornum = 0) = 0;
#ifdef WINDOWS
/** "Fake" file descriptor. This is windows-specific.
*/
int m_internalFd;
/** Pointer to read event. We delete this so the buffer can't be used
* after the socket is deleted, and so it doesn't leak memory
*/
void* m_readEvent;
/** Pointer to a write event.
*/
void* m_writeEvent;
/** Pointer to an accept event.
*/
void* m_acceptEvent;
#endif
};
/** Provides basic file-descriptor-based I/O support.
* The actual socketengine class presents the
* same interface on all operating systems, but
* its private members and internal behaviour
* should be treated as blackboxed, and vary
* from system to system and upon the config
* settings chosen by the server admin. The current
* version supports select, epoll and kqueue.
* The configure script will enable a socket engine
* based upon what OS is detected, and will derive
* a class from SocketEngine based upon what it finds.
* The derived classes file will also implement a
* classfactory, SocketEngineFactory, which will
* create a derived instance of SocketEngine using
* polymorphism so that the core and modules do not
* have to be aware of which SocketEngine derived
* class they are using.
*/
class CoreExport SocketEngine : public Extensible
{
protected:
/** Owner/Creator
*/
InspIRCd* ServerInstance;
/** Handle to socket engine, where needed.
*/
int EngineHandle;
/** Current number of descriptors in the engine
*/
int CurrentSetSize;
/** Reference table, contains all current handlers
*/
EventHandler* ref[MAX_DESCRIPTORS];
public:
/** Constructor.
* The constructor transparently initializes
* the socket engine which the ircd is using.
* Please note that if there is a catastrophic
* failure (for example, you try and enable
* epoll on a 2.4 linux kernel) then this
* function may bail back to the shell.
* @param Instance The creator/owner of this object
*/
SocketEngine(InspIRCd* Instance);
/** Destructor.
* The destructor transparently tidies up
* any resources used by the socket engine.
*/
virtual ~SocketEngine();
/** Add an EventHandler object to the engine.
* Use AddFd to add a file descriptor to the
* engine and have the socket engine monitor
* it. You must provide an object derived from
* EventHandler which implements HandleEvent()
* and optionally Readable() and Writeable().
* @param eh An event handling object to add
*/
virtual bool AddFd(EventHandler* eh);
/** If you call this function and pass it an
* event handler, that event handler will
* receive the next available write event,
* even if the socket is a readable socket only.
* Developers should avoid constantly keeping
* an eventhandler in the writeable state,
* as this will consume large amounts of
* CPU time.
* @param eh An event handler which wants to
* receive the next writeability event.
*/
virtual void WantWrite(EventHandler* eh);
/** Returns the maximum number of file descriptors
* you may store in the socket engine at any one time.
* @return The maximum fd value
*/
virtual int GetMaxFds();
/** Returns the number of file descriptor slots
* which are available for storing fds.
* @return The number of remaining fd's
*/
virtual int GetRemainingFds();
/** Delete an event handler from the engine.
* This function call deletes an EventHandler
* from the engine, returning true if it succeeded
* and false if it failed. This does not free the
* EventHandler pointer using delete, if this is
* required you must do this yourself.
* Note on forcing deletes. DO NOT DO THIS! This is
* extremely dangerous and will most likely render the
* socketengine dead. This was added only for handling
* very rare cases where broken 3rd party libs destroys
* the OS socket beyond our control. If you can't explain
* in minute details why forcing is absolutely necessary
* then you don't need it. That was a NO!
* @param eh The event handler object to remove
* @param force *DANGEROUS* See method description!
* @return True if the event handler was removed
*/
virtual bool DelFd(EventHandler* eh, bool force = false);
/** Returns true if a file descriptor exists in
* the socket engine's list.
* @param fd The event handler to look for
* @return True if this fd has an event handler
*/
virtual bool HasFd(int fd);
/** Returns the EventHandler attached to a specific fd.
* If the fd isnt in the socketengine, returns NULL.
* @param fd The event handler to look for
* @return A pointer to the event handler, or NULL
*/
virtual EventHandler* GetRef(int fd);
/** Waits for events and dispatches them to handlers.
* Please note that this doesnt wait long, only
* a couple of milliseconds. It returns the number of
* events which occured during this call.
* This method will dispatch events to their handlers
* by calling their EventHandler::HandleEvent()
* methods with the neccessary EventType value.
* @return The number of events which have occured.
*/
virtual int DispatchEvents();
/** Returns the socket engines name.
* This returns the name of the engine for use
* in /VERSION responses.
* @return The socket engine name
*/
virtual std::string GetName();
};
#endif
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