readingQueue.hh

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#ifndef READING_QUEUE
#define READING_QUEUE

#include <vector>
#include <map>
#include <queue>
#include "readingQueue.hh"

class DbEntry;

typedef std::map<int, std::queue<DbEntry*>*> QueueMap;

class ReadingQueue {
 private:
  /// nodes from Data
  const std::vector<DbEntry*>& nodes_arr;

  /// nodes delayed, map: thread_id -> queue
  QueueMap delayed_treads;
  QueueMap::iterator it;

  unsigned last_read = 0;    /// node id from nodes_arr currently read
  int delayed_count = 0;     /// how many nodes delayed
  int delayed_cd_count = 0;  /// if zero, read delayed again
  const int DELAYED_CD = 1;  /// delayed cooldown

  /// how many nodes tried until success;
  /// increment if failed
  /// refresh on success
  int node_misses = 0;

  bool read_delayed = false;

  inline QueueMap::iterator nextNonemptyIt(QueueMap::iterator it);

 public:
  explicit ReadingQueue(const std::vector<DbEntry*>& nodes);

  DbEntry* next(bool& delayed);

  /// whether nodes_arr is processed and all queues are empty
  bool canRead();

  /// notify regarding last processed entry
  void update(bool success);

  /// put into delayed queue
  void readLater(DbEntry* delayed);
};

#endif