зеркало из https://github.com/mozilla/pjs.git
72 строки
2.8 KiB
C++
72 строки
2.8 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
|
|
* The contents of this file are subject to the Netscape 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/NPL/
|
|
*
|
|
* 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 Netscape are
|
|
* Copyright (C) 1998-1999 Netscape Communications Corporation. All
|
|
* Rights Reserved.
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* 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"
|
|
|
|
class nsSegmentedBuffer;
|
|
|
|
class nsStorageStream : public nsIStorageStream,
|
|
public nsIOutputStream
|
|
{
|
|
public:
|
|
nsStorageStream();
|
|
virtual ~nsStorageStream();
|
|
|
|
NS_METHOD Init(PRUint32 segmentSize, PRUint32 maxSize, nsIMemory *segmentAllocator = 0);
|
|
|
|
NS_DECL_ISUPPORTS
|
|
NS_DECL_NSISTORAGESTREAM
|
|
NS_DECL_NSIOUTPUTSTREAM
|
|
|
|
friend class nsStorageInputStream;
|
|
|
|
private:
|
|
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_
|