gecko-dev/xpcom/ds/nsByteBuffer.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: NPL 1.1/GPL 2.0/LGPL 2.1
*
* 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.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Pierre Phaneuf <pp@ludusdesign.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either 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 NPL, 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 NPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "nsByteBuffer.h"
#include "nsIInputStream.h"
#include "nsCRT.h"
#define MIN_BUFFER_SIZE 32
ByteBufferImpl::ByteBufferImpl(void)
: mBuffer(NULL), mSpace(0), mLength(0)
{
}
NS_IMETHODIMP
ByteBufferImpl::Init(PRUint32 aBufferSize)
{
if (aBufferSize < MIN_BUFFER_SIZE) {
aBufferSize = MIN_BUFFER_SIZE;
}
mSpace = aBufferSize;
mLength = 0;
mBuffer = new char[aBufferSize];
return mBuffer ? NS_OK : NS_ERROR_OUT_OF_MEMORY;
}
NS_IMPL_ISUPPORTS1(ByteBufferImpl,nsIByteBuffer)
ByteBufferImpl::~ByteBufferImpl()
{
if (nsnull != mBuffer) {
delete[] mBuffer;
mBuffer = nsnull;
}
mLength = 0;
}
NS_METHOD
ByteBufferImpl::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult)
{
if (aOuter)
return NS_ERROR_NO_AGGREGATION;
ByteBufferImpl* it = new ByteBufferImpl();
if (nsnull == it)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(it);
nsresult rv = it->QueryInterface(aIID, (void**)aResult);
NS_RELEASE(it);
return rv;
}
NS_IMETHODIMP_(PRUint32)
ByteBufferImpl::GetLength(void) const
{
return mLength;
}
NS_IMETHODIMP_(PRUint32)
ByteBufferImpl::GetBufferSize(void) const
{
return mSpace;
}
NS_IMETHODIMP_(char*)
ByteBufferImpl::GetBuffer(void) const
{
return mBuffer;
}
NS_IMETHODIMP_(PRBool)
ByteBufferImpl::Grow(PRUint32 aNewSize)
{
if (aNewSize < MIN_BUFFER_SIZE) {
aNewSize = MIN_BUFFER_SIZE;
}
char* newbuf = new char[aNewSize];
if (nsnull != newbuf) {
if (0 != mLength) {
memcpy(newbuf, mBuffer, mLength);
}
delete[] mBuffer;
mBuffer = newbuf;
return PR_TRUE;
}
return PR_FALSE;
}
NS_IMETHODIMP_(PRInt32)
ByteBufferImpl::Fill(nsresult* aErrorCode, nsIInputStream* aStream,
PRUint32 aKeep)
{
NS_PRECONDITION(nsnull != aStream, "null stream");
NS_PRECONDITION(aKeep <= mLength, "illegal keep count");
if ((nsnull == aStream) || (PRUint32(aKeep) > PRUint32(mLength))) {
// whoops
*aErrorCode = NS_BASE_STREAM_ILLEGAL_ARGS;
return -1;
}
if (0 != aKeep) {
// Slide over kept data
memmove(mBuffer, mBuffer + (mLength - aKeep), aKeep);
}
// Read in some new data
mLength = aKeep;
PRUint32 nb;
*aErrorCode = aStream->Read(mBuffer + aKeep, mSpace - aKeep, &nb);
if (NS_SUCCEEDED(*aErrorCode)) {
mLength += nb;
}
else
nb = 0;
return nb;
}
NS_COM nsresult NS_NewByteBuffer(nsIByteBuffer** aInstancePtrResult,
nsISupports* aOuter,
PRUint32 aBufferSize)
{
nsresult rv;
nsIByteBuffer* buf;
rv = ByteBufferImpl::Create(aOuter, NS_GET_IID(nsIByteBuffer), (void**)&buf);
if (NS_FAILED(rv)) return rv;
rv = buf->Init(aBufferSize);
if (NS_FAILED(rv)) {
NS_RELEASE(buf);
return rv;
}
*aInstancePtrResult = buf;
return rv;
}