netwerk/cache/src/nsCacheEntryDescriptor.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 nsCacheEntryDescriptor.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, 22-February-2001
  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
  42 #ifndef _nsCacheEntryDescriptor_h_
  43 #define _nsCacheEntryDescriptor_h_
  44
  45 #include "nsICacheEntryDescriptor.h"
  46 #include "nsCacheEntry.h"
  47 #include "nsIInputStream.h"
  48 #include "nsIOutputStream.h"
  49
  50 /******************************************************************************
  51 * nsCacheEntryDescriptor
  52 *******************************************************************************/
  53 class nsCacheEntryDescriptor :
  54     public PRCList,
  55     public nsICacheEntryDescriptor
  56 {
  57 public:
  58     NS_DECL_ISUPPORTS
  59     NS_DECL_NSICACHEENTRYDESCRIPTOR
  60     NS_DECL_NSICACHEENTRYINFO
  61
  62     nsCacheEntryDescriptor(nsCacheEntry * entry, nsCacheAccessMode  mode);
  63     virtual ~nsCacheEntryDescriptor();
  64
  65     /**
  66      * utility method to attempt changing data size of associated entry
  67      */
  68     nsresult  RequestDataSizeChange(PRInt32 deltaSize);
  69
  70     /**
  71      * methods callbacks for nsCacheService
  72      */
  73     nsCacheEntry * CacheEntry(void)      { return mCacheEntry; }
  74     void           ClearCacheEntry(void) { mCacheEntry = nsnull; }
  75
  76 private:
  77
  78
  79      /*************************************************************************
  80       * input stream wrapper class -
  81       *
  82       * The input stream wrapper references the descriptor, but the descriptor
  83       * doesn't need any references to the stream wrapper.
  84       *************************************************************************/
  85      class nsInputStreamWrapper : public nsIInputStream {
  86      private:
  87          nsCacheEntryDescriptor    * mDescriptor;
  88          nsCOMPtr<nsIInputStream>    mInput;
  89          PRUint32                    mStartOffset;
  90          PRBool                      mInitialized;
  91      public:
  92          NS_DECL_ISUPPORTS
  93          NS_DECL_NSIINPUTSTREAM
  94
  95          nsInputStreamWrapper(nsCacheEntryDescriptor * desc, PRUint32 off)
  96              : mDescriptor(desc)
  97              , mStartOffset(off)
  98              , mInitialized(PR_FALSE)
  99          {
 100              NS_ADDREF(mDescriptor);
 101          }
 102          virtual ~nsInputStreamWrapper()
 103          {
 104              NS_RELEASE(mDescriptor);
 105          }
 106
 107      private:
 108          nsresult LazyInit();
 109          nsresult EnsureInit() { return mInitialized ? NS_OK : LazyInit(); }
 110      };
 111      friend class nsInputStreamWrapper;
 112
 113
 114      /*************************************************************************
 115       * output stream wrapper class -
 116       *
 117       * The output stream wrapper references the descriptor, but the descriptor
 118       * doesn't need any references to the stream wrapper.
 119       *************************************************************************/
 120      class nsOutputStreamWrapper : public nsIOutputStream {
 121      private:
 122          nsCacheEntryDescriptor *    mDescriptor;
 123          nsCOMPtr<nsIOutputStream>   mOutput;
 124          PRUint32                    mStartOffset;
 125          PRBool                      mInitialized;
 126      public:
 127          NS_DECL_ISUPPORTS
 128          NS_DECL_NSIOUTPUTSTREAM
 129
 130          nsOutputStreamWrapper(nsCacheEntryDescriptor * desc, PRUint32 off)
 131              : mDescriptor(desc)
 132              , mStartOffset(off)
 133              , mInitialized(PR_FALSE)
 134          {
 135              NS_ADDREF(mDescriptor); // owning ref
 136          }
 137          virtual ~nsOutputStreamWrapper()
 138          {
 139              // XXX _HACK_ the storage stream needs this!
 140              Close();
 141              NS_RELEASE(mDescriptor);
 142          }
 143
 144      private:
 145          nsresult LazyInit();
 146          nsresult EnsureInit() { return mInitialized ? NS_OK : LazyInit(); }
 147          nsresult OnWrite(PRUint32 count);
 148      };
 149      friend class nsOutputStreamWrapper;
 150
 151  private:
 152      /**
 153       * nsCacheEntryDescriptor data members
 154       */
 155      nsCacheEntry          * mCacheEntry; // we are a child of the entry
 156      nsCacheAccessMode       mAccessGranted;
 157 };
 158
 159
 160 #endif // _nsCacheEntryDescriptor_h_