zeek/src/iosource/IOSource.h
2014-09-09 16:28:04 -05:00

140 lines
3.3 KiB
C++

// See the file "COPYING" in the main distribution directory for copyright.
#ifndef IOSOURCE_IOSOURCE_H
#define IOSOURCE_IOSOURCE_H
extern "C" {
#include <pcap.h>
}
#include <string>
#include "FD_Set.h"
#include "Timer.h"
namespace iosource {
/**
* Interface class for components providing/consuming data inside Bro's main
* loop.
*/
class IOSource {
public:
/**
* Constructor.
*/
IOSource() { idle = false; closed = false; }
/**
* Destructor.
*/
virtual ~IOSource() {}
/**
* Returns true if source has nothing ready to process.
*/
bool IsIdle() const { return idle; }
/**
* Returns true if more data is to be expected in the future.
* Otherwise, source may be removed.
*/
bool IsOpen() const { return ! closed; }
/**
* Initializes the source. Can be overwritten by derived classes.
*/
virtual void Init() { }
/**
* Finalizes the source when it's being closed. Can be overwritten by
* derived classes.
*/
virtual void Done() { }
/**
* Returns select'able file descriptors for this source. Leaves the
* passed values untouched if not available.
*
* @param read Pointer to container where to insert a read descriptor.
*
* @param write Pointer to container where to insert a write descriptor.
*
* @param except Pointer to container where to insert a except descriptor.
*/
virtual void GetFds(FD_Set* read, FD_Set* write, FD_Set* except) = 0;
/**
* Returns the timestamp (in \a global network time) associated with
* next data item from this source. If the source wants the data
* item to be processed with a local network time, it sets the
* argument accordingly.
*
* This method will be called only when either IsIdle() returns
* false, or select() on one of the fds returned by GetFDs()
* indicates that there's data to process.
*
* Must be overridden by derived classes.
*
* @param network_time A pointer to store the \a local network time
* associated with the next item (as opposed to global network time).
*
* @return The global network time of the next entry, or a value
* smaller than zero if none is available currently.
*/
virtual double NextTimestamp(double* network_time) = 0;
/**
* Processes and consumes next data item.
*
* This method will be called only when either IsIdle() returns
* false, or select() on one of the fds returned by GetFDs()
* indicates that there's data to process.
*
* Must be overridden by derived classes.
*/
virtual void Process() = 0;
/**
* Returns the tag of the timer manafger associated with the last
* procesees data item.
*
* Can be overridden by derived classes.
*
* @return The tag, or null for the global timer manager.
*
*/
virtual TimerMgr::Tag* GetCurrentTag() { return 0; }
/**
* Returns a descriptual tag representing the source for debugging.
*
* Can be overridden by derived classes.
*
* @return The debugging name.
*/
virtual const char* Tag() = 0;
protected:
/*
* Callback for derived classes to call when they have gone dry
* temporarily.
*
* @param is_idle True if the source is idle currently.
*/
void SetIdle(bool is_idle) { idle = is_idle; }
/*
* Callback for derived class to call when they have shutdown.
*
* @param is_closed True if the source is now closed.
*/
void SetClosed(bool is_closed) { closed = is_closed; }
private:
bool idle;
bool closed;
};
}
#endif