netwerk/cache/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 #include "nsCacheService.h"
  50 #include "nsIDiskCacheStreamInternal.h"
  51
  52 /******************************************************************************
  53 * nsCacheEntryDescriptor
  54 *******************************************************************************/
  55 class nsCacheEntryDescriptor :
  56     public PRCList,
  57     public nsICacheEntryDescriptor
  58 {
  59 public:
  60     NS_DECL_ISUPPORTS
  61     NS_DECL_NSICACHEENTRYDESCRIPTOR
  62     NS_DECL_NSICACHEENTRYINFO
  63
  64     nsCacheEntryDescriptor(nsCacheEntry * entry, nsCacheAccessMode  mode);
  65     virtual ~nsCacheEntryDescriptor();
  66
  67     /**
  68      * utility method to attempt changing data size of associated entry
  69      */
  70     nsresult  RequestDataSizeChange(PRInt32 deltaSize);
  71
  72     /**
  73      * methods callbacks for nsCacheService
  74      */
  75     nsCacheEntry * CacheEntry(void)      { return mCacheEntry; }
  76     void           ClearCacheEntry(void) { mCacheEntry = nsnull; }
  77
  78     void           CloseOutput(void)
  79     {
  80       if (mOutput) {
  81         nsCOMPtr<nsIDiskCacheStreamInternal> tmp (do_QueryInterface(mOutput));
  82         if (tmp)
  83           tmp->CloseInternal();
  84         else
  85           mOutput->Close();
  86
  87         mOutput = nsnull;
  88       }
  89     }
  90
  91 private:
  92
  93
  94      /*************************************************************************
  95       * input stream wrapper class -
  96       *
  97       * The input stream wrapper references the descriptor, but the descriptor
  98       * doesn't need any references to the stream wrapper.
  99       *************************************************************************/
 100      class nsInputStreamWrapper : public nsIInputStream {
 101      private:
 102          nsCacheEntryDescriptor    * mDescriptor;
 103          nsCOMPtr<nsIInputStream>    mInput;
 104          PRUint32                    mStartOffset;
 105          PRBool                      mInitialized;
 106      public:
 107          NS_DECL_ISUPPORTS
 108          NS_DECL_NSIINPUTSTREAM
 109
 110          nsInputStreamWrapper(nsCacheEntryDescriptor * desc, PRUint32 off)
 111              : mDescriptor(desc)
 112              , mStartOffset(off)
 113              , mInitialized(PR_FALSE)
 114          {
 115              NS_ADDREF(mDescriptor);
 116          }
 117          virtual ~nsInputStreamWrapper()
 118          {
 119              NS_RELEASE(mDescriptor);
 120          }
 121
 122      private:
 123          nsresult LazyInit();
 124          nsresult EnsureInit() { return mInitialized ? NS_OK : LazyInit(); }
 125      };
 126      friend class nsInputStreamWrapper;
 127
 128
 129      /*************************************************************************
 130       * output stream wrapper class -
 131       *
 132       * The output stream wrapper references the descriptor, but the descriptor
 133       * doesn't need any references to the stream wrapper.
 134       *************************************************************************/
 135      class nsOutputStreamWrapper : public nsIOutputStream {
 136      private:
 137          nsCacheEntryDescriptor *    mDescriptor;
 138          nsCOMPtr<nsIOutputStream>   mOutput;
 139          PRUint32                    mStartOffset;
 140          PRBool                      mInitialized;
 141      public:
 142          NS_DECL_ISUPPORTS
 143          NS_DECL_NSIOUTPUTSTREAM
 144
 145          nsOutputStreamWrapper(nsCacheEntryDescriptor * desc, PRUint32 off)
 146              : mDescriptor(desc)
 147              , mStartOffset(off)
 148              , mInitialized(PR_FALSE)
 149          {
 150              NS_ADDREF(mDescriptor); // owning ref
 151          }
 152          virtual ~nsOutputStreamWrapper()
 153          {
 154              // XXX _HACK_ the storage stream needs this!
 155              Close();
 156              {
 157              nsCacheServiceAutoLock lock;
 158              mDescriptor->mOutput = nsnull;
 159              }
 160              NS_RELEASE(mDescriptor);
 161          }
 162
 163      private:
 164          nsresult LazyInit();
 165          nsresult EnsureInit() { return mInitialized ? NS_OK : LazyInit(); }
 166          nsresult OnWrite(PRUint32 count);
 167      };
 168      friend class nsOutputStreamWrapper;
 169
 170  private:
 171      /**
 172       * nsCacheEntryDescriptor data members
 173       */
 174      nsCacheEntry          * mCacheEntry; // we are a child of the entry
 175      nsCacheAccessMode       mAccessGranted;
 176      nsIOutputStream       * mOutput;
 177 };
 178
 179
 180 #endif // _nsCacheEntryDescriptor_h_