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nsCacheEntryDescriptor.h
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00001 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
00002  *
00003  * ***** BEGIN LICENSE BLOCK *****
00004  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
00005  *
00006  * The contents of this file are subject to the Mozilla Public License Version
00007  * 1.1 (the "License"); you may not use this file except in compliance with
00008  * the License. You may obtain a copy of the License at
00009  * http://www.mozilla.org/MPL/
00010  *
00011  * Software distributed under the License is distributed on an "AS IS" basis,
00012  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
00013  * for the specific language governing rights and limitations under the
00014  * License.
00015  *
00016  * The Original Code is nsCacheEntryDescriptor.h, released
00017  * February 22, 2001.
00018  *
00019  * The Initial Developer of the Original Code is
00020  * Netscape Communications Corporation.
00021  * Portions created by the Initial Developer are Copyright (C) 2001
00022  * the Initial Developer. All Rights Reserved.
00023  *
00024  * Contributor(s):
00025  *   Gordon Sheridan, 22-February-2001
00026  *
00027  * Alternatively, the contents of this file may be used under the terms of
00028  * either the GNU General Public License Version 2 or later (the "GPL"), or
00029  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
00030  * in which case the provisions of the GPL or the LGPL are applicable instead
00031  * of those above. If you wish to allow use of your version of this file only
00032  * under the terms of either the GPL or the LGPL, and not to allow others to
00033  * use your version of this file under the terms of the MPL, indicate your
00034  * decision by deleting the provisions above and replace them with the notice
00035  * and other provisions required by the GPL or the LGPL. If you do not delete
00036  * the provisions above, a recipient may use your version of this file under
00037  * the terms of any one of the MPL, the GPL or the LGPL.
00038  *
00039  * ***** END LICENSE BLOCK ***** */
00040 
00041 
00042 #ifndef _nsCacheEntryDescriptor_h_
00043 #define _nsCacheEntryDescriptor_h_
00044 
00045 #include "nsICacheEntryDescriptor.h"
00046 #include "nsCacheEntry.h"
00047 #include "nsIInputStream.h"
00048 #include "nsIOutputStream.h"
00049 
00050 /******************************************************************************
00051 * nsCacheEntryDescriptor
00052 *******************************************************************************/
00053 class nsCacheEntryDescriptor :
00054     public PRCList,
00055     public nsICacheEntryDescriptor
00056 {
00057 public:
00058     NS_DECL_ISUPPORTS
00059     NS_DECL_NSICACHEENTRYDESCRIPTOR
00060     NS_DECL_NSICACHEENTRYINFO
00061     
00062     nsCacheEntryDescriptor(nsCacheEntry * entry, nsCacheAccessMode  mode);
00063     virtual ~nsCacheEntryDescriptor();
00064     
00068     nsresult  RequestDataSizeChange(PRInt32 deltaSize);
00069     
00073     nsCacheEntry * CacheEntry(void)      { return mCacheEntry; }
00074     void           ClearCacheEntry(void) { mCacheEntry = nsnull; }
00075 
00076 private:
00077 
00078 
00079      /*************************************************************************
00080       * input stream wrapper class -
00081       *
00082       * The input stream wrapper references the descriptor, but the descriptor
00083       * doesn't need any references to the stream wrapper.
00084       *************************************************************************/
00085      class nsInputStreamWrapper : public nsIInputStream {
00086      private:
00087          nsCacheEntryDescriptor    * mDescriptor;
00088          nsCOMPtr<nsIInputStream>    mInput;
00089          PRUint32                    mStartOffset;
00090          PRBool                      mInitialized;
00091      public:
00092          NS_DECL_ISUPPORTS
00093          NS_DECL_NSIINPUTSTREAM
00094 
00095          nsInputStreamWrapper(nsCacheEntryDescriptor * desc, PRUint32 off)
00096              : mDescriptor(desc)
00097              , mStartOffset(off)
00098              , mInitialized(PR_FALSE)
00099          {
00100              NS_ADDREF(mDescriptor);
00101          }
00102          virtual ~nsInputStreamWrapper()
00103          {
00104              NS_RELEASE(mDescriptor);
00105          }
00106 
00107      private:
00108          nsresult LazyInit();
00109          nsresult EnsureInit() { return mInitialized ? NS_OK : LazyInit(); }
00110      };
00111      friend class nsInputStreamWrapper;
00112 
00113 
00114      /*************************************************************************
00115       * output stream wrapper class -
00116       *
00117       * The output stream wrapper references the descriptor, but the descriptor
00118       * doesn't need any references to the stream wrapper.
00119       *************************************************************************/
00120      class nsOutputStreamWrapper : public nsIOutputStream {
00121      private:
00122          nsCacheEntryDescriptor *    mDescriptor;
00123          nsCOMPtr<nsIOutputStream>   mOutput;
00124          PRUint32                    mStartOffset;
00125          PRBool                      mInitialized;
00126      public:
00127          NS_DECL_ISUPPORTS
00128          NS_DECL_NSIOUTPUTSTREAM
00129 
00130          nsOutputStreamWrapper(nsCacheEntryDescriptor * desc, PRUint32 off)
00131              : mDescriptor(desc)
00132              , mStartOffset(off)
00133              , mInitialized(PR_FALSE)
00134          {
00135              NS_ADDREF(mDescriptor); // owning ref
00136          }
00137          virtual ~nsOutputStreamWrapper()
00138          { 
00139              // XXX _HACK_ the storage stream needs this!
00140              Close();
00141              NS_RELEASE(mDescriptor);
00142          }
00143 
00144      private:
00145          nsresult LazyInit();
00146          nsresult EnsureInit() { return mInitialized ? NS_OK : LazyInit(); }
00147          nsresult OnWrite(PRUint32 count);
00148      };
00149      friend class nsOutputStreamWrapper;
00150 
00151  private:
00155      nsCacheEntry          * mCacheEntry; // we are a child of the entry
00156      nsCacheAccessMode       mAccessGranted;
00157 };
00158 
00159 
00160 #endif // _nsCacheEntryDescriptor_h_