1 /****************************************************************************
2 ** $Id: qt/qasyncio.h   3.3.8   edited Jan 11 14:38 $
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4 ** Definition of asynchronous I/O classes
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6 ** Created : 970617
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37 
38 #ifndef QASYNCIO_H
39 #define QASYNCIO_H
40 
41 #ifndef QT_H
42 #include "qobject.h"
43 #include "qsignal.h"
44 #include "qtimer.h"
45 #endif // QT_H
46 
47 #ifndef QT_NO_ASYNC_IO
48 
49 class QIODevice;
50 
51 class Q_EXPORT QAsyncIO {
52 public:
53     virtual ~QAsyncIO();
54     void connect(QObject*, const char *member);
55 
56 protected:
57     void ready();
58 
59 private:
60     QSignal signal;
61 };
62 
63 class Q_EXPORT QDataSink : public QAsyncIO {
64 public:
65     // Call this to know how much I can take.
66     virtual int readyToReceive()=0;
67     virtual void receive(const uchar*, int count)=0;
68     virtual void eof()=0;
69     void maybeReady();
70 };
71 
72 class Q_EXPORT QDataSource : public QAsyncIO {
73 public:
74     virtual int readyToSend()=0; // returns -1 when never any more ready
75     virtual void sendTo(QDataSink*, int count)=0;
76     void maybeReady();
77 
78     virtual bool rewindable() const;
79     virtual void enableRewind(bool);
80     virtual void rewind();
81 };
82 
83 class Q_EXPORT QIODeviceSource : public QDataSource {
84     const int buf_size;
85     uchar *buffer;
86     QIODevice* iod;
87     bool rew;
88 
89 public:
90     QIODeviceSource(QIODevice*, int bufsize=4096);
91    ~QIODeviceSource();
92 
93     int readyToSend();
94     void sendTo(QDataSink* sink, int n);
95     bool rewindable() const;
96     void enableRewind(bool on);
97     void rewind();
98 };
99 
100 class Q_EXPORT QDataPump : public QObject {
101     Q_OBJECT
102     int interval;
103     QTimer timer;
104     QDataSource* source;
105     QDataSink* sink;
106 
107 public:
108     QDataPump(QDataSource*, QDataSink*);
109 
110 private slots:
111     void kickStart();
112     void tryToPump();
113 };
114 
115 #endif	// QT_NO_ASYNC_IO
116 
117 #endif
118