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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998-1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
* The storage stream provides an internal buffer that can be filled by a
* client using a single output stream. One or more independent input streams
* can be created to read the data out non-destructively. The implementation
* uses a segmented buffer internally to avoid realloc'ing of large buffers,
* with the attendant performance loss and heap fragmentation.
*/
#ifndef _nsStorageStream_h_
#define _nsStorageStream_h_
#include "nsIStorageStream.h"
#include "nsIOutputStream.h"
#include "nsMemory.h"
#define NS_STORAGESTREAM_CID \
{ /* 669a9795-6ff7-4ed4-9150-c34ce2971b63 */ \
0x669a9795, \
0x6ff7, \
0x4ed4, \
{0x91, 0x50, 0xc3, 0x4c, 0xe2, 0x97, 0x1b, 0x63} \
}
#define NS_STORAGESTREAM_CONTRACTID "@mozilla.org/storagestream;1"
#define NS_STORAGESTREAM_CLASSNAME "Storage Stream"
class nsSegmentedBuffer;
class nsStorageStream : public nsIStorageStream,
public nsIOutputStream
{
public:
nsStorageStream();
NS_DECL_ISUPPORTS
NS_DECL_NSISTORAGESTREAM
NS_DECL_NSIOUTPUTSTREAM
friend class nsStorageInputStream;
private:
~nsStorageStream();
nsSegmentedBuffer* mSegmentedBuffer;
PRUint32 mSegmentSize; // All segments, except possibly the last, are of this size
// Must be power-of-2
PRUint32 mSegmentSizeLog2; // log2(mSegmentSize)
PRBool mWriteInProgress; // true, if an un-Close'ed output stream exists
PRInt32 mLastSegmentNum; // Last segment # in use, -1 initially
char* mWriteCursor; // Pointer to next byte to be written
char* mSegmentEnd; // Pointer to one byte after end of segment
// containing the write cursor
PRUint32 mLogicalLength; // Number of bytes written to stream
NS_METHOD Seek(PRInt32 aPosition);
PRUint32 SegNum(PRUint32 aPosition) {return aPosition >> mSegmentSizeLog2;}
PRUint32 SegOffset(PRUint32 aPosition) {return aPosition & (mSegmentSize - 1);}
};
#endif // _nsStorageStream_h_
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