gecko-dev/xpcom/io/nsScriptableInputStream.cpp

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4.4 KiB
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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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* 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
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*
* 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):
*
* 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
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#include "nsScriptableInputStream.h"
#include "nsMemory.h"
#include "nsString.h"
NS_IMPL_ISUPPORTS1(nsScriptableInputStream, nsIScriptableInputStream)
// nsIScriptableInputStream methods
NS_IMETHODIMP
nsScriptableInputStream::Close(void) {
if (!mInputStream) return NS_ERROR_NOT_INITIALIZED;
return mInputStream->Close();
}
NS_IMETHODIMP
nsScriptableInputStream::Init(nsIInputStream *aInputStream) {
if (!aInputStream) return NS_ERROR_NULL_POINTER;
mInputStream = aInputStream;
return NS_OK;
}
NS_IMETHODIMP
nsScriptableInputStream::Available(PRUint32 *_retval) {
if (!mInputStream) return NS_ERROR_NOT_INITIALIZED;
return mInputStream->Available(_retval);
}
NS_IMETHODIMP
nsScriptableInputStream::Read(PRUint32 aCount, char **_retval) {
nsresult rv = NS_OK;
PRUint32 count = 0;
char *buffer = nsnull;
if (!mInputStream) return NS_ERROR_NOT_INITIALIZED;
rv = mInputStream->Available(&count);
if (NS_FAILED(rv)) return rv;
// bug716556 - Ensure count+1 doesn't overflow
count = NS_MIN(NS_MIN(count, aCount), PR_UINT32_MAX - 1);
buffer = (char*)nsMemory::Alloc(count+1); // make room for '\0'
if (!buffer) return NS_ERROR_OUT_OF_MEMORY;
PRUint32 amtRead = 0;
rv = mInputStream->Read(buffer, count, &amtRead);
if (NS_FAILED(rv)) {
nsMemory::Free(buffer);
return rv;
}
buffer[amtRead] = '\0';
*_retval = buffer;
return NS_OK;
}
NS_IMETHODIMP
nsScriptableInputStream::ReadBytes(PRUint32 aCount, nsACString &_retval) {
if (!mInputStream) {
return NS_ERROR_NOT_INITIALIZED;
}
_retval.SetLength(aCount);
if (_retval.Length() != aCount) {
return NS_ERROR_OUT_OF_MEMORY;
}
char *ptr = _retval.BeginWriting();
PRUint32 totalBytesRead = 0;
while (1) {
PRUint32 bytesRead;
nsresult rv = mInputStream->Read(ptr + totalBytesRead,
aCount - totalBytesRead,
&bytesRead);
if (NS_FAILED(rv)) {
return rv;
}
totalBytesRead += bytesRead;
if (totalBytesRead == aCount) {
break;
}
// If we have read zero bytes, we have hit EOF.
if (bytesRead == 0) {
_retval.Truncate();
return NS_ERROR_FAILURE;
}
}
return NS_OK;
}
nsresult
nsScriptableInputStream::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult) {
if (aOuter) return NS_ERROR_NO_AGGREGATION;
nsScriptableInputStream *sis = new nsScriptableInputStream();
if (!sis) return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(sis);
nsresult rv = sis->QueryInterface(aIID, aResult);
NS_RELEASE(sis);
return rv;
}