vdr/filter.h

/*
 * filter.h: Section filter
 *
 * See the main source file 'vdr.c' for copyright information and
 * how to reach the author.
 *
 * $Id: filter.h 5.1 2021/03/16 15:10:54 kls Exp $
 */

#ifndef __FILTER_H
#define __FILTER_H

#include <sys/types.h>
#include "tools.h"

#define DEPRECATED_SECTIONSYNCER_SYNC_REPEAT 1

class cSectionSyncer {
private:
  int currentVersion;
  int currentSection;
  bool random;
  bool synced;
  bool complete;
  uint32_t segments;  // bit flags for the 32 segments
  uchar sections[32]; // holds 32 * 8 = 256 bits, as flags for the sections
  void SetSectionFlag(uchar Section, bool On) { if (On) sections[Section / 8] |= (1 << (Section % 8)); else sections[Section / 8] &= ~(1 << (Section % 8)); }
  bool GetSectionFlag(uchar Section) { return sections[Section / 8] & (1 << (Section % 8)); }
public:
  cSectionSyncer(bool Random = false);
       ///< Sets up a new section syncer.
       ///< Call Check() to see whether a given section needs processing. Once the section
       ///< has been processed, call Processed() to mark it as such. If, for any reason,
       ///< processing is not completed after calling Check(), nothing special needs to be
       ///< done. Just don't call Processed() and a later call to Check() with the same
       ///< SectionNumber will return true again.
       ///< If Random is true, sections can be processed in random order, not necessarily
       ///< starting with section 0.
  void Reset(void);
  bool Check(uchar Version, int SectionNumber);
       ///< Returns true if Version is not the current version, or the given SectionNumber has not
       ///< been marked as processed, yet. Sections are handled in ascending order, starting at 0,
       ///< unless Random is true in the constructor call.
  bool Processed(int SectionNumber, int LastSectionNumber, int SegmentLastSectionNumber = -1);
       ///< Marks the given SectionNumber as processed.
       ///< LastSectionNumber is used to determine whether all sections have been processed.
       ///< SegmentLastSectionNumber can be given to handle partially filled segments (like,
       ///< for instance in the EIT).
       ///< Returns true if all sections have been processed.
  bool Complete(void) { return complete; }
       ///< Returns true if all sections have been processed.
#if DEPRECATED_SECTIONSYNCER_SYNC_REPEAT
  void Repeat(void);
  bool Sync(uchar Version, int Number, int LastNumber);
#endif
  };

class cSectionSyncerRandom : public cSectionSyncer {
  ///< Helper class for having an array of random section syncers.
public:
  cSectionSyncerRandom(void): cSectionSyncer(true) {}
  };

class cFilterData : public cListObject {
public:
  u_short pid;
  u_char tid;
  u_char mask;
  bool sticky;
  cFilterData(void);
  cFilterData(u_short Pid, u_char Tid, u_char Mask, bool Sticky);
  cFilterData& operator= (const cFilterData &FilterData);
  bool Is(u_short Pid, u_char Tid, u_char Mask);
  bool Matches(u_short Pid, u_char Tid);
  };

class cChannel;
class cSectionHandler;

class cFilter : public cListObject {
  friend class cSectionHandler;
private:
  cSectionHandler *sectionHandler;
  cList<cFilterData> data;
  bool on;
protected:
  cFilter(void);
  cFilter(u_short Pid, u_char Tid, u_char Mask = 0xFF);
  virtual ~cFilter();
  virtual void SetStatus(bool On);
       ///< Turns this filter on or off, depending on the value of On.
       ///< If the filter is turned off, any filter data that has been
       ///< added without the Sticky parameter set to 'true' will be
       ///< automatically deleted. Those parameters that have been added
       ///< with Sticky set to 'true' will be automatically reused when
       ///< SetStatus(true) is called.
  virtual void Process(u_short Pid, u_char Tid, const u_char *Data, int Length) = 0;
       ///< Processes the data delivered to this filter.
       ///< Pid and Tid is one of the combinations added to this filter by
       ///< a previous call to Add(), Data is a pointer to Length bytes of
       ///< data. This function will be called from the section handler's
       ///< thread, so it has to use proper locking mechanisms in case it
       ///< accesses any global data. It is guaranteed that if several cFilters
       ///< are attached to the same cSectionHandler, only _one_ of them has
       ///< its Process() function called at any given time. It is allowed
       ///< that more than one cFilter are set up to receive the same Pid/Tid.
       ///< The Process() function must return as soon as possible.
  int Source(void);
       ///< Returns the source of the data delivered to this filter.
  int Transponder(void);
       ///< Returns the transponder of the data delivered to this filter.
  const cChannel *Channel(void);
       ///< Returns the channel of the data delivered to this filter.
  bool Matches(u_short Pid, u_char Tid);
       ///< Indicates whether this filter wants to receive data from the given Pid/Tid.
  void Set(u_short Pid, u_char Tid, u_char Mask = 0xFF);
       ///< Sets the given filter data by calling Add() with Sticky = true.
  void Add(u_short Pid, u_char Tid, u_char Mask = 0xFF, bool Sticky = false);
       ///< Adds the given filter data to this filter.
       ///< If Sticky is true, this will survive a status change, otherwise
       ///< it will be automatically deleted.
  void Del(u_short Pid, u_char Tid, u_char Mask = 0xFF);
       ///< Deletes the given filter data from this filter.
  };

#endif //__FILTER_H