gecko-dev/xpcom/io/nsByteArrayInputStream.cpp

148 строки
3.8 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.
*
*/
#include "nsByteArrayInputStream.h"
#include "nsMemory.h"
NS_IMPL_THREADSAFE_ISUPPORTS2(nsByteArrayInputStream, nsIInputStream, nsIByteArrayInputStream)
nsByteArrayInputStream::nsByteArrayInputStream (char *buffer, PRUint32 bytes)
: _buffer (buffer), _nbytes (bytes), _pos (0)
{
NS_INIT_REFCNT ();
}
nsByteArrayInputStream::~nsByteArrayInputStream ()
{
if (_buffer != NULL)
nsMemory::Free (_buffer);
}
NS_IMETHODIMP
nsByteArrayInputStream::Available (PRUint32* aResult)
{
if (aResult == NULL)
return NS_ERROR_NULL_POINTER;
if (_nbytes == 0 || _buffer == NULL)
*aResult = 0;
else
*aResult = _nbytes - _pos;
return NS_OK;
}
NS_IMETHODIMP
nsByteArrayInputStream::Read (char* aBuffer, PRUint32 aCount, PRUint32 *aNumRead)
{
if (aBuffer == NULL || aNumRead == NULL)
return NS_ERROR_NULL_POINTER;
if (_nbytes == 0)
return NS_ERROR_FAILURE;
if (aCount == 0 || _pos == _nbytes)
*aNumRead = 0;
else
{
NS_ASSERTION (_buffer != NULL, "Stream buffer has been released - there's an ownership problem somewhere!");
if (_buffer == NULL)
*aNumRead = 0;
else
if (aCount > _nbytes - _pos)
{
memcpy (aBuffer, &_buffer[_pos], *aNumRead = _nbytes - _pos);
_pos = _nbytes;
}
else
{
memcpy (aBuffer, &_buffer[_pos], *aNumRead = aCount);
_pos += aCount;
}
}
return NS_OK;
}
NS_IMETHODIMP
nsByteArrayInputStream::ReadSegments(nsWriteSegmentFun writer, void * aClosure, PRUint32 aCount, PRUint32 *aNumRead)
{
nsresult rv = NS_OK;
if (aNumRead == NULL)
return NS_ERROR_NULL_POINTER;
if (_nbytes == 0)
return NS_ERROR_FAILURE;
if (aCount == 0 || _pos == _nbytes)
*aNumRead = 0;
else {
NS_ASSERTION (_buffer != NULL, "Stream buffer has been released - there's an ownership problem somewhere!");
PRUint32 readCount = PR_MIN(aCount, (_nbytes - _pos));
if (_buffer == NULL)
*aNumRead = 0;
else
rv = writer (this, aClosure, &_buffer[_pos],
_pos, readCount, aNumRead);
_pos += *aNumRead;
}
return rv;
}
NS_IMETHODIMP
nsByteArrayInputStream::IsNonBlocking(PRBool *aNonBlocking)
{
*aNonBlocking = PR_TRUE;
return NS_OK;
}
NS_IMETHODIMP
nsByteArrayInputStream::Close ()
{
if (_buffer != NULL)
{
nsMemory::Free (_buffer);
_buffer = NULL;
_nbytes = 0;
}
else
return NS_ERROR_FAILURE;
return NS_OK;
}
NS_COM nsresult
NS_NewByteArrayInputStream (nsIByteArrayInputStream* *aResult, char * buffer, unsigned long bytes)
{
if (aResult == NULL)
return NS_ERROR_NULL_POINTER;
nsIByteArrayInputStream * stream = new nsByteArrayInputStream (buffer, bytes);
if (!stream)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF (stream);
*aResult = stream;
return NS_OK;
}