add

+/*
+ * Copyright 2007 Stephen Liu
+ * For license terms, see the file COPYING along with this library.
+ */
+
+#ifndef __spiochannel_hpp__
+#define __spiochannel_hpp__
+
+class SP_Session;
+class SP_Buffer;
+
+#ifdef WIN32
+typedef struct spwin32buffer sp_evbuffer_t;
+#else
+typedef struct evbuffer sp_evbuffer_t;
+#endif
+
+struct iovec;
+
+class SP_IOChannel {
+public:
+	virtual ~SP_IOChannel();
+
+	// call by an independence thread, can block
+	// return -1 : terminate session, 0 : continue
+	virtual int init( int fd ) = 0;
+
+	// run in event-loop thread, cannot block
+	// return the number of bytes received, or -1 if an error occurred.
+	virtual int receive( SP_Session * session ) = 0;
+
+	// run in event-loop thread, cannot block
+	// return the number of bytes sent, or -1 if an error occurred.
+	virtual int transmit( SP_Session * session );
+
+protected:
+	static sp_evbuffer_t * getEvBuffer( SP_Buffer * buffer );
+
+	// returns the number of bytes written, or -1 if an error occurred.
+	virtual int write_vec( struct iovec * iovArray, int iovSize ) = 0;
+};
+
+class SP_IOChannelFactory {
+public:
+	virtual ~SP_IOChannelFactory();
+
+	virtual SP_IOChannel * create() const = 0;
+};
+
+class SP_DefaultIOChannelFactory : public SP_IOChannelFactory {
+public:
+	SP_DefaultIOChannelFactory();
+	virtual ~SP_DefaultIOChannelFactory();
+
+	virtual SP_IOChannel * create() const;
+};
+
+class SP_DefaultIOChannel : public SP_IOChannel {
+public:
+	SP_DefaultIOChannel();
+	~SP_DefaultIOChannel();
+
+	virtual int init( int fd );
+	virtual int receive( SP_Session * session );
+
+protected:
+	virtual int write_vec( struct iovec * iovArray, int iovSize );
+	int mFd;
+};
+
+#endif
+