include/unireplicategen.h

   1 /* -*- Mode: C++ -*-
   2  * Worldvisions Weaver Software:
   3  *   Copyright (C) 2002 Net Integration Technologies, Inc.
   4  *
   5  * A UniConf generator that caches keys/values in memory.
   6  */
   7 #ifndef __UNIREPLICATEGEN_H
   8 #define __UNIREPLICATEGEN_H
   9
  10 #include "uniconftree.h"
  11 #include "wvlog.h"
  12
  13 /**
  14  * A UniConf generator that replicates generators between an ordered list
  15  * of inner generators, with the priority given by the list.
  16  *
  17  * Replication of the data occurs when the generator is contructed, whenever
  18  * prepend() or append() is called, or whenever any of the generators in the
  19  * list goes from !isok() to isok().  If two inner generators contain different
  20  * values for the same before replication, then they will both have the value
  21  * of the earlier generator (as ordered in the moniker) after replication.
  22  *
  23  * If an asynchronous change occurs in any of the inner generators, the
  24  * new value will be set in all generators irrespective of priority.
  25  */
  26 class UniReplicateGen : public UniConfGen
  27 {
  28 private:
  29     struct Gen
  30     {
  31         IUniConfGen *gen;
  32         bool was_ok;
  33         bool auto_free;
  34
  35         Gen(IUniConfGen *_gen, bool _auto_free)
  36                 : gen(_gen), was_ok(gen->isok()), auto_free(_auto_free) {}
  37         ~Gen() { if (auto_free) WVRELEASE(gen); }
  38
  39         bool isok() { return was_ok = gen->isok(); }
  40     };
  41     DeclareWvList(Gen);
  42     GenList gens;
  43
  44     bool processing_callback;
  45
  46     Gen *first_ok() const;
  47
  48     void replicate_if_any_have_become_ok();
  49
  50 protected:
  51     void replicate(const UniConfKey &key = "/");
  52     void deltacallback(Gen *src_gen, const UniConfKey &key,
  53                        WvStringParm value);
  54
  55 public:
  56     UniReplicateGen();
  57     UniReplicateGen(const IUniConfGenList &_gens, bool autofree = true);
  58     virtual ~UniReplicateGen();
  59
  60     void prepend(IUniConfGen *gen, bool autofree = true);
  61     void append(IUniConfGen *gen, bool autofree = true);
  62
  63     /***** Overridden members *****/
  64     virtual bool isok();
  65     virtual void commit();
  66     virtual bool refresh();
  67     virtual void flush_buffers() { }
  68     virtual void set(const UniConfKey &key, WvStringParm value);
  69     virtual void setv(const UniConfPairList &pairs);
  70     virtual WvString get(const UniConfKey &key);
  71     virtual Iter *iterator(const UniConfKey &key);
  72 };
  73
  74 #endif // __UNIREPLICATEGEN_H