netwerk/cache/src/nsDiskCacheStreams.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 nsDiskCacheStreams.h, released
  17  * June 13, 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
  42 #ifndef _nsDiskCacheStreams_h_
  43 #define _nsDiskCacheStreams_h_
  44
  45 #include "nsDiskCacheBinding.h"
  46
  47 #include "nsCache.h"
  48
  49 #include "nsIInputStream.h"
  50 #include "nsIOutputStream.h"
  51
  52 #include "pratom.h"
  53
  54 class nsDiskCacheInputStream;
  55 class nsDiskCacheOutputStream;
  56 class nsDiskCacheDevice;
  57
  58 class nsDiskCacheStreamIO : public nsISupports {
  59 public:
  60              nsDiskCacheStreamIO(nsDiskCacheBinding *   binding);
  61     virtual ~nsDiskCacheStreamIO();
  62
  63     NS_DECL_ISUPPORTS
  64
  65     nsresult    GetInputStream(PRUint32 offset, nsIInputStream ** inputStream);
  66     nsresult    GetOutputStream(PRUint32 offset, nsIOutputStream ** outputStream);
  67
  68     nsresult    CloseOutputStream(nsDiskCacheOutputStream * outputStream);
  69
  70     nsresult    Write( const char * buffer,
  71                        PRUint32     count,
  72                        PRUint32 *   bytesWritten);
  73
  74     nsresult    Seek(PRInt32 whence, PRInt32 offset);
  75     nsresult    Tell(PRUint32 * position);
  76     nsresult    SetEOF();
  77
  78     void        ClearBinding();
  79
  80     void        IncrementInputStreamCount() { PR_AtomicIncrement(&mInStreamCount); }
  81     void        DecrementInputStreamCount()
  82                 {
  83                     PR_AtomicDecrement(&mInStreamCount);
  84                     NS_ASSERTION(mInStreamCount >= 0, "mInStreamCount has gone negative");
  85                 }
  86
  87     // GCC 2.95.2 requires this to be defined, although we never call it.
  88     // and OS/2 requires that it not be private
  89     nsDiskCacheStreamIO() { NS_NOTREACHED("oops"); }
  90 private:
  91
  92
  93     void        Close();
  94     nsresult    OpenCacheFile(PRIntn flags, PRFileDesc ** fd);
  95     nsresult    ReadCacheBlocks();
  96     nsresult    FlushBufferToFile();
  97     void        UpdateFileSize();
  98     void        DeleteBuffer();
  99     nsresult    Flush();
 100
 101
 102     nsDiskCacheBinding *        mBinding;       // not an owning reference
 103     nsDiskCacheDevice *         mDevice;
 104     nsDiskCacheOutputStream *   mOutStream;     // not an owning reference
 105     PRInt32                     mInStreamCount;
 106     nsCOMPtr<nsILocalFile>      mLocalFile;
 107     PRFileDesc *                mFD;
 108
 109     PRUint32                    mStreamPos;     // for Output Streams
 110     PRUint32                    mStreamEnd;
 111     PRUint32                    mBufPos;        // current mark in buffer
 112     PRUint32                    mBufEnd;        // current end of data in buffer
 113     PRUint32                    mBufSize;       // current end of buffer
 114     PRBool                      mBufDirty;
 115     char *                      mBuffer;
 116
 117 };
 118
 119 #endif // _nsDiskCacheStreams_h_