name_cache.h

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#ifndef NAME_CACHE_CLASS
#define NAME_CACHE_CLASS

/*****************************************************************************\
*                                                                             *
*  Name   : name_cache                                                        *
*  Author : Chris Koeritz                                                     *
*                                                                             *
*  Purpose:                                                                   *
*                                                                             *
*    Stores resolved hostnames to avoid repeatedly calling upon the DNS.      *
*                                                                             *
*******************************************************************************
* Copyright (c) 1992-$now By Author.  This program is free software; you can  *
* redistribute it and/or modify it under the terms of the GNU General Public  *
* License as published by the Free Software Foundation; either version 2 of   *
* the License or (at your option) any later version.  This is online at:      *
*     http://www.fsf.org/copyleft/gpl.html                                    *
* Please send any updates to: fred@gruntose.com                               *
\*****************************************************************************/

#include "resolver_dll.h"

// forward.
class dns_entry;
class dns_entry_table;

class RESOLVER_CLASS_STYLE name_cache
{
public:
  name_cache(int maximum_entries);
    // the "maximum_entries" specifies how many names can exist before old
    // names start dropping out of the list.

  ~name_cache();

  void add(const istring &name, const dns_entry &info);
    // enters a network name listing for the readable "name".  if the
    // "resolved" field in "info" is true, then the "info" is considered
    // completely valid and any existing information is updated.  otherwise,
    // only provisional records will be kept.

  bool remove(const istring &name);
    // eliminates the data for "name", if possible.

  dns_entry lookup(const istring &name) const;
    // finds the name information held for the "name" specified.  if the entry
    // could not be found, then the returned item will have an uninitialized
    // address member.

  void show_names(istring &to_fill);
    // returns the full status of the name_cache in the string "to_fill".

private:
  int _max_cache;  // maximum number of entries in the cache.
  mutex *_lock;  // synchronizes access to list.
  dns_entry_table *_name_list;  // the list of names.
};

#endif

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