uniconf/unidefgen.cc

   1 /*
   2  * Worldvisions Weaver Software:
   3  *   Copyright (C) 2002 Net Integration Technologies, Inc.
   4  *
   5  * UniDefGen is a UniConfGen for retrieving data with defaults
   6  */
   7 #include "unidefgen.h"
   8 #include "wvmoniker.h"
   9 //#include "wvstream.h"
  10 #include <ctype.h>
  11 #include <stdlib.h>
  12
  13 #include "wvlinkerhack.h"
  14
  15 WV_LINK(UniDefGen);
  16
  17
  18 // if 'obj' is non-NULL and is a UniConfGen, wrap that; otherwise wrap the
  19 // given moniker.
  20 static IUniConfGen *creator(WvStringParm s, IObject *_obj)
  21 {
  22     return new UniDefGen(wvcreate<IUniConfGen>(s, _obj));
  23 }
  24
  25 // this name is too confusing.  We should deprecate it.
  26 static WvMoniker<IUniConfGen> reg("default", creator);
  27
  28 // a better name for the same thing.
  29 static WvMoniker<IUniConfGen> reg2("wildcard", creator);
  30
  31
  32 UniConfKey UniDefGen::finddefault(const UniConfKey &key, char *p, char *q)
  33 {
  34     UniConfKey result;
  35
  36     if (!p)
  37     {
  38         q++;
  39         if (inner() && inner()->exists(q))
  40             return q;
  41         else
  42             return UniConfKey();
  43     }
  44
  45     // pop the first segment of p to r
  46     char *r = strchr(p, '/');
  47     if (r)
  48         *r++ = '\0';
  49
  50     // append p to q
  51     char *s = strchr(q, '\0');
  52     *s++ = '/';
  53     *s = 0;
  54     q = strcat(q, p);
  55
  56     // try this literal path
  57     result = finddefault(key, r, q);
  58     if (result.numsegments())
  59         return result;
  60
  61     // replace what used to be p with a *
  62     *s++ = '*';
  63     *s = '\0';
  64     result = finddefault(key, r, q);
  65
  66     if (r)
  67         *--r = '/';
  68
  69     return result;
  70 }
  71
  72
  73 WvString UniDefGen::replacewildcard(const UniConfKey &key,
  74                             const UniConfKey &defkey, WvStringParm in)
  75 {
  76     // check if the result wants a wildcard ('*n')
  77     if (in.len() < 2 || in[0] != '*')
  78         return in;
  79
  80     const char *s = in.cstr();
  81     int idx = atoi(s+1);
  82     if (idx == 0)
  83         return in;
  84
  85     // search backwards for segment num of the n'th wildcard
  86     UniConfKey k(defkey);
  87     int loc = key.numsegments();
  88     for (int i = 0; i < idx; i++)
  89     {
  90         if (i != 0)
  91         {
  92             k = k.removelast();
  93             loc--;
  94         }
  95         while (!k.last().iswild())
  96         {
  97             k = k.removelast();
  98             loc--;
  99             if (k.isempty())
 100             {
 101                 // oops, ran out of segments!
 102                 return WvString();
 103             }
 104         }
 105     }
 106
 107
 108     // pull the literal from that segment num of the key
 109     return key.segment(loc-1);
 110 }
 111
 112
 113 bool UniDefGen::keymap(const UniConfKey &unmapped_key, UniConfKey &mapped_key)
 114 {
 115     WvString tmp_key(unmapped_key), tmp("");
 116     char *p = tmp_key.edit();
 117
 118     tmp.setsize(strlen(tmp_key) * 2);
 119     char *q = tmp.edit();
 120     *q = '\0';
 121
 122     mapped_key = finddefault(unmapped_key, p, q);
 123     if (!mapped_key.numsegments())
 124         mapped_key = unmapped_key;
 125     // fprintf(stderr, "mapping '%s' -> '%s'\n", key.cstr(), result.cstr());
 126
 127     return true;
 128 }
 129
 130
 131 WvString UniDefGen::get(const UniConfKey &key)
 132 {
 133     UniConfKey mapped_key;
 134     if (keymap(key, mapped_key))
 135         return replacewildcard(key, mapped_key,
 136                             inner() ? inner()->get(mapped_key) : WvString());
 137     else
 138         return WvString::null;
 139 }
 140
 141
 142 void UniDefGen::set(const UniConfKey &key, WvStringParm value)
 143 {
 144     // no keymap() on set()
 145     if (inner())
 146         inner()->set(key, value);
 147 }