Back to index

lightning-sunbird  0.9+nobinonly
nsDiskCacheStreams.h
Go to the documentation of this file.
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 nsDiskCacheStreams.h, released
00017  * June 13, 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 <gordon@netscape.com>
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 _nsDiskCacheStreams_h_
00043 #define _nsDiskCacheStreams_h_
00044 
00045 #include "nsDiskCacheBinding.h"
00046 
00047 #include "nsCache.h"
00048 
00049 #include "nsIInputStream.h"
00050 #include "nsIOutputStream.h"
00051 
00052 #include "pratom.h"
00053 
00054 class nsDiskCacheInputStream;
00055 class nsDiskCacheOutputStream;
00056 class nsDiskCacheDevice;
00057 
00058 class nsDiskCacheStreamIO : public nsISupports {
00059 public:
00060              nsDiskCacheStreamIO(nsDiskCacheBinding *   binding);
00061     virtual ~nsDiskCacheStreamIO();
00062     
00063     NS_DECL_ISUPPORTS
00064 
00065     nsresult    GetInputStream(PRUint32 offset, nsIInputStream ** inputStream);
00066     nsresult    GetOutputStream(PRUint32 offset, nsIOutputStream ** outputStream);
00067 
00068     nsresult    CloseOutputStream(nsDiskCacheOutputStream * outputStream);
00069         
00070     nsresult    Write( const char * buffer,
00071                        PRUint32     count,
00072                        PRUint32 *   bytesWritten);
00073 
00074     nsresult    Seek(PRInt32 whence, PRInt32 offset);
00075     nsresult    Tell(PRUint32 * position);    
00076     nsresult    SetEOF();
00077 
00078     void        ClearBinding();
00079     
00080     void        IncrementInputStreamCount() { PR_AtomicIncrement(&mInStreamCount); }
00081     void        DecrementInputStreamCount()
00082                 {
00083                     PR_AtomicDecrement(&mInStreamCount);
00084                     NS_ASSERTION(mInStreamCount >= 0, "mInStreamCount has gone negative");
00085                 }
00086 
00087     // GCC 2.95.2 requires this to be defined, although we never call it.
00088     // and OS/2 requires that it not be private
00089     nsDiskCacheStreamIO() { NS_NOTREACHED("oops"); }
00090 private:
00091 
00092 
00093     void        Close();
00094     nsresult    OpenCacheFile(PRIntn flags, PRFileDesc ** fd);
00095     nsresult    ReadCacheBlocks();
00096     nsresult    FlushBufferToFile(PRBool  clearBuffer); // XXX clearBuffer is always PR_TRUE
00097     PRUint32    WriteToBuffer(const char * buffer, PRUint32 count);
00098     nsresult    UpdateFileSize();
00099     void        DeleteBuffer();
00100     nsresult    Flush();
00101 
00102 
00103     nsDiskCacheBinding *        mBinding;
00104     nsDiskCacheDevice *         mDevice;
00105     nsDiskCacheOutputStream *   mOutStream;     // not an owning reference
00106     PRInt32                     mInStreamCount;
00107     nsCOMPtr<nsILocalFile>      mLocalFile;
00108     PRFileDesc *                mFD;
00109 
00110     PRUint32                    mStreamPos;     // for Output Streams
00111     PRUint32                    mStreamEnd;
00112     PRUint32                    mBufPos;        // current mark in buffer
00113     PRUint32                    mBufEnd;        // current end of data in buffer
00114     PRUint32                    mBufSize;       // current end of buffer
00115     PRBool                      mBufDirty;
00116     char *                      mBuffer;
00117     
00118 };
00119 
00120 #endif // _nsDiskCacheStreams_h_