netwerk/cache/src/nsCacheMetaData.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  *
   3  * ***** BEGIN LICENSE BLOCK *****
   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
   8  * the License. You may obtain a copy of the License at
   9  * http://www.mozilla.org/MPL/
  10  *
  11  * Software distributed under the License is distributed on an "AS IS" basis,
  12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  13  * for the specific language governing rights and limitations under the
  14  * License.
  15  *
  16  * The Original Code is nsCacheMetaData.h, released
  17  * February 22, 2001.
  18  *
  19  * The Initial Developer of the Original Code is
  20  * Netscape Communications Corporation.
  21  * Portions created by the Initial Developer are Copyright (C) 2001
  22  * the Initial Developer. All Rights Reserved.
  23  *
  24  * Contributor(s):
  25  *   Gordon Sheridan <gordon@netscape.com>
  26  *
  27  * Alternatively, the contents of this file may be used under the terms of
  28  * either the GNU General Public License Version 2 or later (the "GPL"), or
  29  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  30  * in which case the provisions of the GPL or the LGPL are applicable instead
  31  * of those above. If you wish to allow use of your version of this file only
  32  * under the terms of either the GPL or the LGPL, and not to allow others to
  33  * use your version of this file under the terms of the MPL, indicate your
  34  * decision by deleting the provisions above and replace them with the notice
  35  * and other provisions required by the GPL or the LGPL. If you do not delete
  36  * the provisions above, a recipient may use your version of this file under
  37  * the terms of any one of the MPL, the GPL or the LGPL.
  38  *
  39  * ***** END LICENSE BLOCK ***** */
  40
  41 #ifndef _nsCacheMetaData_h_
  42 #define _nsCacheMetaData_h_
  43
  44 #include "nspr.h"
  45 #include "pldhash.h"
  46 #include "nscore.h"
  47 #include "nsString.h"
  48
  49 class nsICacheMetaDataVisitor;
  50
  51 class nsCacheMetaData {
  52 public:
  53     nsCacheMetaData();
  54     ~nsCacheMetaData()  { Clear(); }
  55
  56     void                  Clear();
  57     PRBool                IsEmpty() { return (mData == nsnull); }
  58
  59     const char *          GetElement(const char * key);
  60
  61     nsresult              SetElement(const char * key,
  62                                      const char * value);
  63
  64     PRUint32              Size(void) { return mMetaSize; }
  65
  66     nsresult              FlattenMetaData(char * buffer, PRUint32 bufSize);
  67
  68     nsresult              UnflattenMetaData(const char * buffer, PRUint32 bufSize);
  69
  70     nsresult              VisitElements(nsICacheMetaDataVisitor * visitor);
  71
  72 private:
  73
  74     struct MetaElement
  75     {
  76         struct MetaElement * mNext;
  77         nsCString            mKey;
  78         char                 mValue[1]; // actually, bigger than 1
  79
  80         // MetaElement and mValue are allocated together via:
  81         void *operator new(size_t size,
  82                            const char *value,
  83                            PRUint32 valueSize) CPP_THROW_NEW;
  84     };
  85
  86     MetaElement * mData;
  87     PRUint32      mMetaSize;
  88 };
  89
  90 #endif // _nsCacheMetaData_h