include/unimountgen.h

   1 /* -*- Mode: C++ -*-
   2  * Worldvisions Weaver Software:
   3  *   Copyright (C) 1997-2002 Net Integration Technologies, Inc.
   4  *
   5  * Defines a UniConfGen that manages a tree of UniConfGen instances.
   6  */
   7 #ifndef __UNIMOUNTGEN_H
   8 #define __UNIMOUNTGEN_H
   9
  10 #include "uniconfgen.h"
  11 #include "wvmoniker.h"
  12 #include "wvstringlist.h"
  13 #include "wvtr1.h"
  14
  15
  16 /** The UniMountTree implementation realized as a UniConfGen. */
  17 class UniMountGen : public UniConfGen
  18 {
  19 protected:
  20
  21     // Class to hold the generator with its mountpoint
  22     class UniGenMount
  23     {
  24     public:
  25         UniGenMount(IUniConfGen *gen, const UniConfKey &key)
  26             : gen(gen), key(key)
  27             { }
  28
  29         xplc_ptr<IUniConfGen> gen;
  30         UniConfKey key;
  31     };
  32
  33     typedef class WvList<UniGenMount> MountList;
  34     MountList mounts;
  35
  36     /** undefined. */
  37     UniMountGen(const UniMountGen &other);
  38
  39 public:
  40     /** Creates an empty UniConf tree with no mounted stores. */
  41     UniMountGen();
  42
  43     /** Destroys the UniConf tree along with all uncommitted data. */
  44     virtual ~UniMountGen();
  45
  46     void zap();
  47
  48     /**
  49      * Mounts a generator at a key using a moniker.
  50
  51      * Returns the generator instance pointer, or NULL on failure.
  52      */
  53     virtual IUniConfGen *mount(const UniConfKey &key,
  54                                WvStringParm moniker,
  55                                bool refresh);
  56
  57     /**
  58      * Mounts a generator at a key.
  59      * Takes ownership of the supplied generator instance.
  60      *
  61      * "key" is the key
  62      * "gen" is the generator instance
  63      * "refresh" is if true, refreshes the generator after mount
  64      * Returns: the generator instance pointer, or NULL on failure
  65      */
  66     virtual IUniConfGen *mountgen(const UniConfKey &key,
  67                                   IUniConfGen *gen,
  68                                   bool refresh);
  69
  70     /**
  71      * Unmounts the generator at a key and releases it.
  72      *
  73      * "gen" is the generator instance
  74      * "commit" is if true, commits the generator before unmount
  75      */
  76     virtual void unmount(IUniConfGen *gen, bool commit);
  77
  78     /**
  79      * Finds the generator that owns a key.
  80      *
  81      * If the key exists, returns the generator that provides its
  82      * contents.  Otherwise returns the generator that would be
  83      * updated if a value were set.
  84      *
  85      * "key" is the key
  86      * "mountpoint" is if not NULL, replaced with the mountpoint
  87      *        path on success
  88      * Returns: the handle, or a null handle if none
  89      */
  90     virtual IUniConfGen *whichmount(const UniConfKey &key,
  91                                    UniConfKey *mountpoint);
  92
  93     /** Determines if a key is a mountpoint. */
  94     virtual bool ismountpoint(const UniConfKey &key);
  95
  96     /***** Overridden members *****/
  97
  98     virtual bool exists(const UniConfKey &key);
  99     virtual bool haschildren(const UniConfKey &key);
 100     virtual WvString get(const UniConfKey &key);
 101     virtual void set(const UniConfKey &key, WvStringParm value);
 102     virtual void setv(const UniConfPairList &pairs);
 103     virtual void commit();
 104     virtual bool refresh();
 105     virtual void flush_buffers() { }
 106     virtual Iter *iterator(const UniConfKey &key);
 107     virtual Iter *recursiveiterator(const UniConfKey &key);
 108
 109 private:
 110     /** Find the active generator for a given key. */
 111     UniGenMount *findmount(const UniConfKey &key);
 112     /** Find a unique active generator a given key, will return NULL if
 113      *  there are other generators beneath that key. */
 114     UniGenMount *findmountunder(const UniConfKey &key);
 115
 116     // Trim the key so it matches the generator starting point
 117     UniConfKey trimkey(const UniConfKey &foundkey, const UniConfKey &key)
 118         { return key.removefirst(foundkey.numsegments()); }
 119
 120     /** Called by generators when a key changes. */
 121     void gencallback(const UniConfKey &base, const UniConfKey &key,
 122                      WvStringParm value);
 123
 124     void makemount(const UniConfKey &key);
 125
 126     /** Return true if the given key has a subkey
 127      *  if you used findmount first, give the result as a parameter to
 128      *  improve efficiency*/
 129     bool has_subkey(const UniConfKey &key, UniGenMount *found = NULL);
 130
 131     struct UniGenMountPairs;
 132     DeclareWvDict(UniGenMountPairs, WvFastString, key);
 133
 134 };
 135
 136 #endif //__UNIMOUNTGEN_H