include/wx/private/fdiodispatcher.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/private/fdiodispatcher.h
   3 // Purpose:     classes for dispatching IO notifications for file descriptors
   4 // Authors:     Lukasz Michalski
   5 // Created:     December 2006
   6 // Copyright:   (c) Lukasz Michalski
   7 // Licence:     wxWindows licence
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10 #ifndef _WX_PRIVATE_FDIODISPATCHER_H_
  11 #define _WX_PRIVATE_FDIODISPATCHER_H_
  12
  13 #include "wx/hashmap.h"
  14 #include "wx/private/fdiohandler.h"
  15
  16 // those flags describes sets where descriptor should be added
  17 enum wxFDIODispatcherEntryFlags
  18 {
  19     wxFDIO_INPUT = 1,
  20     wxFDIO_OUTPUT = 2,
  21     wxFDIO_EXCEPTION = 4,
  22     wxFDIO_ALL = wxFDIO_INPUT | wxFDIO_OUTPUT | wxFDIO_EXCEPTION
  23 };
  24
  25 // base class for wxSelectDispatcher and wxEpollDispatcher
  26 class WXDLLIMPEXP_BASE wxFDIODispatcher
  27 {
  28 public:
  29     enum { TIMEOUT_INFINITE = -1 };
  30
  31     // return the global dispatcher to be used for IO events, can be NULL only
  32     // if wxSelectDispatcher wasn't compiled into the library at all as
  33     // creating it never fails
  34     //
  35     // don't delete the returned pointer
  36     static wxFDIODispatcher *Get();
  37
  38     // if we have any registered handlers, check for any pending events to them
  39     // and dispatch them -- this is used from wxX11 and wxDFB event loops
  40     // implementation
  41     static void DispatchPending();
  42
  43     // register handler for the given descriptor with the dispatcher, return
  44     // true on success or false on error
  45     virtual bool RegisterFD(int fd, wxFDIOHandler *handler, int flags) = 0;
  46
  47     // modify descriptor flags or handler, return true on success
  48     virtual bool ModifyFD(int fd, wxFDIOHandler *handler, int flags) = 0;
  49
  50     // unregister descriptor previously registered with RegisterFD()
  51     virtual bool UnregisterFD(int fd) = 0;
  52
  53     // check if any events are currently available without dispatching them
  54     virtual bool HasPending() const = 0;
  55
  56     // wait for an event for at most timeout milliseconds and process it;
  57     // return the number of events processed (possibly 0 if timeout expired) or
  58     // -1 if an error occurred
  59     virtual int Dispatch(int timeout = TIMEOUT_INFINITE) = 0;
  60
  61     virtual ~wxFDIODispatcher() { }
  62 };
  63
  64 //entry for wxFDIOHandlerMap
  65 struct wxFDIOHandlerEntry
  66 {
  67     wxFDIOHandlerEntry()
  68     {
  69     }
  70
  71     wxFDIOHandlerEntry(wxFDIOHandler *handler_, int flags_)
  72         : handler(handler_),
  73           flags(flags_)
  74     {
  75     }
  76
  77     wxFDIOHandler *handler;
  78     int flags;
  79 };
  80
  81 // this hash is used to map file descriptors to their handlers
  82 WX_DECLARE_HASH_MAP(
  83   int,
  84   wxFDIOHandlerEntry,
  85   wxIntegerHash,
  86   wxIntegerEqual,
  87   wxFDIOHandlerMap
  88 );
  89
  90 // FDIODispatcher that holds map fd <-> FDIOHandler, this should be used if
  91 // this map isn't maintained elsewhere already as it is usually needed anyhow
  92 //
  93 // notice that all functions for FD management have implementation
  94 // in the base class and should be called from the derived classes
  95 class WXDLLIMPEXP_BASE wxMappedFDIODispatcher : public wxFDIODispatcher
  96 {
  97 public:
  98     // find the handler for the given fd, return NULL if none
  99     wxFDIOHandler *FindHandler(int fd) const;
 100
 101     // register handler for the given descriptor with the dispatcher, return
 102     // true on success or false on error
 103     virtual bool RegisterFD(int fd, wxFDIOHandler *handler, int flags);
 104
 105     // modify descriptor flags or handler, return true on success
 106     virtual bool ModifyFD(int fd, wxFDIOHandler *handler, int flags);
 107
 108     // unregister descriptor previously registered with RegisterFD()
 109     virtual bool UnregisterFD(int fd);
 110
 111     virtual ~wxMappedFDIODispatcher() { }
 112
 113 protected:
 114     // the fd -> handler map containing all the registered handlers
 115     wxFDIOHandlerMap m_handlers;
 116 };
 117
 118 #endif // _WX_PRIVATE_FDIODISPATCHER_H_