cdsa/cdsa_utilities/cssmlist.h

   1 /*
   2  * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please obtain
   7  * a copy of the License at http://www.apple.com/publicsource and read it before
   8  * using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
  12  * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
  13  * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  14  * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
  15  * specific language governing rights and limitations under the License.
  16  */
  17
  18
  19 //
  20 // cssmlist - CSSM_LIST operational utilities
  21 //
  22 #ifndef _H_CSSMLIST
  23 #define _H_CSSMLIST
  24
  25 #include <Security/utilities.h>
  26 #include <Security/cssmalloc.h>
  27 #include <Security/walkers.h>
  28
  29 #ifdef _CPP_CSSMLIST
  30 #pragma export on
  31 #endif
  32
  33 namespace Security
  34 {
  35
  36 class CssmList;
  37 class TypedList;
  38
  39
  40 //
  41 // A POD Wrapper for CSSM_LIST_ELEMENTs.
  42 // List elements are pseudo-polymorphic, so we provide ways to get and
  43 // set their three personalities. It's up to the caller to get this right;
  44 // you mustn't (for example) call the data() method on a list element that
  45 // is not of (element) type CSSM_LIST_ELEMENT_DATUM. To violate this rule
  46 // will get you an assertion (not exception).
  47 //
  48 class ListElement : public PodWrapper<ListElement, CSSM_LIST_ELEMENT> {
  49 public:
  50     // list element chaining
  51         CSSM_LIST_ELEMENT_TYPE type() const { return ElementType; }
  52         ListElement * &next() { return ListElement::overlayVar(NextElement); }
  53         ListElement *next() const { return ListElement::overlay(NextElement); }
  54         ListElement *last();
  55
  56     // CssmData personality
  57         ListElement(const CssmData &data);
  58     ListElement(CssmAllocator &alloc, string stringData);
  59         CssmData &data();
  60         const CssmData &data() const;
  61         ListElement &operator = (const CssmData &data);
  62         operator CssmData &() { return data(); }
  63         operator string () const { return data(); }
  64         bool operator == (const CssmData &other) const  { return data() == other; }
  65         bool operator != (const CssmData &other) const  { return data() != other; }
  66
  67     template <class T>
  68     void extract(T &destination, CSSM_RETURN error = CSSM_ERRCODE_INVALID_DATA)
  69     { data().extract(destination, error); }
  70
  71     // CssmList (sublist) personality
  72         ListElement(const CssmList &list);
  73         CssmList &list();
  74         const CssmList &list() const;
  75         ListElement &operator = (const CssmList &list);
  76         operator CssmList &() { return list(); }
  77         operator const CssmList &() const { return list(); }
  78     operator TypedList &();
  79     operator const TypedList &() const;
  80
  81     // WORDID (number) personality
  82         ListElement(CSSM_WORDID_TYPE word);
  83         CSSM_WORDID_TYPE word() const;
  84         ListElement &operator = (CSSM_WORDID_TYPE word);
  85     operator CSSM_WORDID_TYPE () const { return word(); }
  86         bool operator == (CSSM_WORDID_TYPE other) const { return word() == other; }
  87         bool operator != (CSSM_WORDID_TYPE other) const { return word() != other; }
  88
  89 public:
  90         void *operator new (size_t size, CssmAllocator &alloc)
  91         { return alloc.malloc(size); }
  92
  93         void clear(CssmAllocator &alloc);               // free my contents
  94 };
  95
  96 } // end namespace Security
  97
  98 // specialize destroy() to call clear() for cleanup
  99 inline void destroy(ListElement *elem, CssmAllocator &alloc)
 100 {
 101         elem->clear(alloc);
 102         alloc.free(elem);
 103 }
 104
 105 namespace Security
 106 {
 107
 108 //
 109 // A POD Wrapper for CSSM_LIST.
 110 // CssmList does no memory allocations. Retrieval functions return pointers or
 111 // references into existing content, and modifiers modify in-place without any
 112 // attempt to release previous dynamic content. May the Leaking God be with You.
 113 //
 114 class CssmList : public PodWrapper<CssmList, CSSM_LIST> {
 115 public:
 116         CssmList() { ListType = CSSM_LIST_TYPE_UNKNOWN; Head = Tail = NULL; }
 117         CssmList(const CssmList &list)  { *(CssmList *)this = list; }
 118
 119 public:
 120         CSSM_LIST_TYPE kind() const { return ListType; }        // type() reserved for TypedList
 121
 122         ListElement &operator [] (unsigned ix) const;
 123         unsigned int length() const;
 124         ListElement * &first() { return ListElement::overlayVar(Head); }
 125         ListElement *first() const { return ListElement::overlay(Head); }
 126         ListElement *last() const { return ListElement::overlay(Tail); }
 127         bool empty() const { return first() == NULL; }
 128
 129         CssmList &append(ListElement *elem);
 130         CssmList &insert(ListElement *elem, ListElement *before);
 131         CssmList &remove(ListElement *elem);
 132         CssmList &operator += (ListElement *elem) { return append(elem); }
 133         CssmList &operator -= (ListElement *elem) { return remove(elem); }
 134
 135     // logically remove the first element (skip it)
 136     void snip();
 137
 138 public:
 139         void clear(CssmAllocator &alloc);               // free my contents
 140 };
 141
 142 } // end namespace Security
 143
 144 inline void destroy(CssmList *list, CssmAllocator &alloc)
 145 {
 146         list->clear(alloc);
 147         alloc.free(list);
 148 }
 149
 150 namespace Security
 151 {
 152
 153 //
 154 // Enhanced overlay for CssmLists whose first element is known to be a wordid.
 155 //
 156 class TypedList : public CssmList {
 157 public:
 158     TypedList(const CSSM_LIST &list) { *(CSSM_LIST *)this = list; }
 159         TypedList(CssmAllocator &alloc, CSSM_WORDID_TYPE type);
 160         TypedList(CssmAllocator &alloc, CSSM_WORDID_TYPE type, ListElement *elem1);
 161         TypedList(CssmAllocator &alloc, CSSM_WORDID_TYPE type, ListElement *elem1, ListElement *elem2);
 162
 163         bool isProper() const;  // format check (does not throw)
 164         static TypedList &overlay(CSSM_LIST &list)
 165         { return static_cast<TypedList &>(list); }
 166         static const TypedList &overlay(const CSSM_LIST &list)
 167         { return static_cast<const TypedList &>(list); }
 168
 169         CSSM_WORDID_TYPE type() const
 170         { assert(isProper()); return first()->word(); }
 171 };
 172
 173 inline ListElement::operator TypedList &()
 174 { return TypedList::overlay(operator CssmList &()); }
 175
 176 inline ListElement::operator const TypedList &() const
 177 { return TypedList::overlay(operator const CssmList &()); }
 178
 179
 180 //
 181 // Data walkers to parse list elements and lists.
 182 // @@@ Walking lists by recursing over next() is stack intensive. Do this in CssmList walker by loop?
 183 //
 184 namespace DataWalkers
 185 {
 186
 187 template <class Action>
 188 ListElement *walk(Action &operate, ListElement * &elem)
 189 {
 190         operate(elem);
 191         switch (elem->type()) {
 192         case CSSM_LIST_ELEMENT_DATUM:
 193                 walk(operate, elem->data());
 194                 break;
 195         case CSSM_LIST_ELEMENT_SUBLIST:
 196                 walk(operate, elem->list());
 197                 break;
 198         case CSSM_LIST_ELEMENT_WORDID:
 199                 break;
 200         default:
 201                 assert(false);
 202         }
 203         if (elem->next())
 204                 walk(operate, elem->next());
 205         return elem;
 206 }
 207
 208 template <class Action>
 209 ListElement *walk(Action &operate, CSSM_LIST_ELEMENT * &elem)
 210 { walk(operate, ListElement::overlay(elem)); }
 211
 212 template <class Action>
 213 void walk(Action &operate, CssmList &list)
 214 {
 215         if (!list.empty()) {
 216                 walk(operate, list.first());
 217                 if (operate.needsRelinking)
 218                         list.Tail = list.first()->last();       // re-establish "tail" link
 219         }
 220 }
 221
 222 template <class Action>
 223 void walk(Action &operate, CSSM_LIST &list)
 224 { walk(operate, CssmList::overlay(list)); }
 225
 226 template <class Action>
 227 void walk(Action &operate, const CSSM_LIST &list)
 228 { walk(operate, const_cast<CSSM_LIST &>(list)); }
 229
 230 template <class Action>
 231 void walk(Action &operate, const CssmList &list)
 232 { walk(operate, const_cast<CssmList &>(list)); }
 233
 234
 235 template <class Action>
 236 CSSM_LIST *walk(Action &operate, CSSM_LIST * &list)
 237 {
 238         operate(list);
 239         walk(operate, *list);
 240         return list;
 241 }
 242
 243 } // end namespace DataWalkers
 244
 245 };      // end namespace Security
 246
 247 #ifdef _CPP_CSSMLIST
 248 #pragma export off
 249 #endif
 250
 251 #endif //_H_CSSMLIST