utils/wvmoniker.cc

   1 /*
   2  * Worldvisions Weaver Software:
   3  *   Copyright (C) 1997-2002 Net Integration Technologies, Inc.
   4  *
   5  * Support for monikers, which are strings that you can pass to a magic
   6  * factory to get objects supporting a particular interface.  See wvmoniker.h.
   7  */
   8 #include "wvmonikerregistry.h"
   9 #include "strutils.h"
  10 #include <wvassert.h>
  11 #include <stdio.h>
  12
  13 #if 0
  14 # define DEBUGLOG(fmt, args...) fprintf(stderr, fmt, ## args)
  15 #else
  16 #ifndef _MSC_VER
  17 # define DEBUGLOG(fmt, args...)
  18 #else  // MS Visual C++ doesn't support varags preproc macros
  19 # define DEBUGLOG
  20 #endif
  21 #endif
  22
  23
  24 static unsigned WvHash(const UUID &_uuid)
  25 {
  26     unsigned val = 0;
  27     unsigned int *uuid = (unsigned int *)&_uuid;
  28     int max = sizeof(UUID)/sizeof(*uuid);
  29
  30     for (int count = 0; count < max; count++)
  31         val += uuid[count];
  32
  33     return val;
  34 }
  35
  36
  37 DeclareWvScatterDict(WvMonikerRegistry, UUID, reg_iid);
  38 static WvMonikerRegistryDict *regs;
  39
  40
  41
  42 WvMonikerRegistry::WvMonikerRegistry(const UUID &iid)
  43     : reg_iid(iid), dict(10)
  44 {
  45     DEBUGLOG("WvMonikerRegistry creating.\n");
  46     refcount = 0;
  47 }
  48
  49
  50 WvMonikerRegistry::~WvMonikerRegistry()
  51 {
  52     DEBUGLOG("WvMonikerRegistry destroying.\n");
  53 }
  54
  55
  56 void WvMonikerRegistry::add(WvStringParm id, WvMonikerCreateFunc *func)
  57 {
  58     DEBUGLOG("WvMonikerRegistry register(%s).\n", id.cstr());
  59     wvassert(!dict[id], id);
  60     dict.add(new Registration(id, func), true);
  61 }
  62
  63
  64 void WvMonikerRegistry::del(WvStringParm id)
  65 {
  66     DEBUGLOG("WvMonikerRegistry unregister(%s).\n", id.cstr());
  67     assert(dict[id]);
  68     dict.remove(dict[id]);
  69 }
  70
  71
  72 void *WvMonikerRegistry::create(WvStringParm _s, IObject *obj)
  73 {
  74     WvString t(_s);
  75     WvString s(trim_string(t.edit()));
  76
  77     char *cptr = strchr(s.edit(), ':');
  78     if (cptr)
  79         *cptr++ = 0;
  80     else
  81         cptr = (char*)"";
  82
  83     DEBUGLOG("WvMonikerRegistry create object ('%s' '%s').\n", s.cstr(), cptr);
  84
  85     Registration *r = dict[s];
  86     if (r)
  87         return r->func(cptr, obj);
  88     else
  89         return NULL;
  90 }
  91
  92
  93 WvMonikerRegistry *WvMonikerRegistry::find_reg(const UUID &iid)
  94 {
  95     DEBUGLOG("WvMonikerRegistry find_reg.\n");
  96
  97     if (!regs)
  98         regs = new WvMonikerRegistryDict(10);
  99
 100     WvMonikerRegistry *reg = (*regs)[iid];
 101
 102     if (!reg)
 103     {
 104         // we have to make one!
 105         reg = new WvMonikerRegistry(iid);
 106         regs->add(reg, true);
 107         reg->addRef(); // one reference for being in the list at all
 108     }
 109
 110     reg->addRef();
 111     return reg;
 112 }
 113
 114
 115 IObject *WvMonikerRegistry::getInterface(const UUID &uuid)
 116 {
 117 #if 0
 118     if (uuid.equals(IObject_IID))
 119     {
 120         addRef();
 121         return this;
 122     }
 123 #endif
 124
 125     // we don't really support any interfaces for now.
 126
 127     return 0;
 128 }
 129
 130
 131 unsigned int WvMonikerRegistry::addRef()
 132 {
 133     DEBUGLOG("WvMonikerRegistry addRef.\n");
 134     return ++refcount;
 135 }
 136
 137
 138 unsigned int WvMonikerRegistry::release()
 139 {
 140     DEBUGLOG("WvMonikerRegistry release.\n");
 141
 142     if (--refcount > 1)
 143         return refcount;
 144
 145     if (refcount == 1)
 146     {
 147         // the list has one reference to us, but it's no longer needed.
 148         // Note: remove() will delete this object!
 149         regs->remove(this);
 150         if (regs->isempty())
 151         {
 152             delete regs;
 153             regs = NULL;
 154         }
 155         return 0;
 156     }
 157
 158     /* protect against re-entering the destructor */
 159     refcount = 1;
 160     delete this;
 161     return 0;
 162 }
 163
 164
 165 WvMonikerBase::WvMonikerBase(const UUID &iid, WvStringParm _id,
 166                              WvMonikerCreateFunc *func)
 167     : id(_id)
 168 {
 169     DEBUGLOG("WvMoniker creating(%s).\n", id.cstr());
 170     reg = WvMonikerRegistry::find_reg(iid);
 171     if (reg)
 172         reg->add(id, func);
 173 }
 174
 175
 176 WvMonikerBase::~WvMonikerBase()
 177 {
 178     DEBUGLOG("WvMoniker destroying(%s).\n", id.cstr());
 179     if (reg)
 180     {
 181         reg->del(id);
 182         WVRELEASE(reg);
 183     }
 184 }
 185
 186
 187 void *wvcreate(const UUID &iid, WvStringParm moniker, IObject *obj)
 188 {
 189     assert(!moniker.isnull());
 190     // fprintf(stderr, "wvcreate: Looking for '%s'\n", moniker.cstr());
 191     WvMonikerRegistry *reg = WvMonikerRegistry::find_reg(iid);
 192     if (reg)
 193     {
 194         void *ret = reg->create(moniker, obj);
 195         WVRELEASE(reg);
 196         return ret;
 197     }
 198     else
 199         return NULL;
 200 }