gecko-dev/xpcom/io/nsStringStream.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** 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):
* mcmullen@netscape.com (original author)
* warren@netscape.com
* alecf@netscape.com
* scc@mozilla.org
* david.gardiner@unisa.edu.au
* fur@netscape.com
* norris@netscape.com
* pinkerton@netscape.com
* davidm@netscape.com
* sfraser@netscape.com
* darin@netscape.com
* bzbarsky@mit.edu
*
* 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 ***** */
/**
* Based on original code from nsIStringStream.cpp
*/
#include "nsStringStream.h"
#include "prerror.h"
#include "plstr.h"
#include "nsReadableUtils.h"
#include "nsCRT.h"
#include "nsISeekableStream.h"
#define NS_FILE_RESULT(x) ns_file_convert_result((PRInt32)x)
#define NS_FILE_FAILURE NS_FILE_RESULT(-1)
static nsresult ns_file_convert_result(PRInt32 nativeErr)
{
return nativeErr ?
NS_ERROR_GENERATE_FAILURE(NS_ERROR_MODULE_FILES,((nativeErr)&0xFFFF))
: NS_OK;
}
//-----------------------------------------------------------------------------
// nsIStringInputStream implementation
//-----------------------------------------------------------------------------
class nsStringInputStream : public nsIStringInputStream
, public nsIRandomAccessStore
{
public:
nsStringInputStream()
: mOffset(0)
, mLastResult(NS_OK)
, mEOF(PR_FALSE)
, mOwned(PR_FALSE)
, mConstString(nsnull)
, mLength(0)
{}
virtual ~nsStringInputStream()
{
if (mOwned)
nsMemory::Free((char*)mConstString);
}
NS_DECL_ISUPPORTS
NS_DECL_NSISTRINGINPUTSTREAM
NS_DECL_NSIINPUTSTREAM
// nsIRandomAccessStore interface
NS_IMETHOD GetAtEOF(PRBool* outAtEOF);
NS_IMETHOD SetAtEOF(PRBool inAtEOF);
NS_DECL_NSISEEKABLESTREAM
protected:
PRInt32 LengthRemaining() const
{
return mLength - mOffset;
}
void Clear()
{
NS_ASSERTION(mConstString || !mOwned,
"Can't have mOwned set and have a null string!");
if (mOwned)
nsMemory::Free((char*)mConstString);
// We're about to get a new string; clear the members that
// would no longer have valid values.
mOffset = 0;
mLastResult = NS_OK;
mEOF = PR_FALSE;
}
PRInt32 mOffset;
nsresult mLastResult;
PRPackedBool mEOF;
PRPackedBool mOwned;
const char* mConstString;
PRInt32 mLength;
};
NS_IMPL_THREADSAFE_ISUPPORTS4(nsStringInputStream,
nsIStringInputStream,
nsIInputStream,
nsIRandomAccessStore,
nsISeekableStream)
/////////
// nsIStringInputStream implementation
/////////
NS_IMETHODIMP
nsStringInputStream::SetData(const char *data, PRInt32 dataLen)
{
if (dataLen < 0)
dataLen = strlen(data);
return AdoptData(nsCRT::strndup(data, dataLen), dataLen);
}
NS_IMETHODIMP
nsStringInputStream::AdoptData(char *data, PRInt32 dataLen)
{
NS_ENSURE_ARG_POINTER(data);
if (dataLen < 0)
dataLen = strlen(data);
Clear();
mConstString = (const char *) data;
mLength = dataLen;
mOwned = PR_TRUE;
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::ShareData(const char *data, PRInt32 dataLen)
{
NS_ENSURE_ARG_POINTER(data);
if (dataLen < 0)
dataLen = strlen(data);
Clear();
mConstString = data;
mLength = dataLen;
mOwned = PR_FALSE;
return NS_OK;
}
/////////
// nsIInputStream implementation
/////////
NS_IMETHODIMP nsStringInputStream::Close()
{
return NS_OK;
}
NS_IMETHODIMP nsStringInputStream::Available(PRUint32 *aLength)
{
NS_PRECONDITION(aLength != nsnull, "null ptr");
if (!aLength)
return NS_ERROR_NULL_POINTER;
*aLength = LengthRemaining();
return NS_OK;
}
NS_IMETHODIMP nsStringInputStream::Read(char* aBuf, PRUint32 aCount,
PRUint32 *aReadCount)
{
NS_PRECONDITION(aBuf != nsnull, "null ptr");
if (!aBuf)
return NS_ERROR_NULL_POINTER;
NS_PRECONDITION(aReadCount != nsnull, "null ptr");
if (!aReadCount)
return NS_ERROR_NULL_POINTER;
if (NS_FAILED(mLastResult))
return mLastResult;
PRInt32 bytesRead;
PRInt32 maxCount = mLength - mOffset;
if ((PRInt32)aCount > maxCount)
bytesRead = maxCount;
else
bytesRead = aCount;
memcpy(aBuf, mConstString + mOffset, bytesRead);
mOffset += bytesRead;
*aReadCount = bytesRead;
if (bytesRead < (PRInt32)aCount)
SetAtEOF(PR_TRUE);
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::ReadSegments(nsWriteSegmentFun writer, void * closure,
PRUint32 aCount, PRUint32 * result)
{
nsresult rv;
PRInt32 maxCount = mLength - mOffset;
if (maxCount == 0) {
*result = 0;
return NS_OK;
}
if ((PRInt32)aCount > maxCount)
aCount = maxCount;
rv = writer(this, closure, mConstString + mOffset,
0, aCount, result);
if (NS_SUCCEEDED(rv))
mOffset += *result;
// errors returned from the writer end here!
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::IsNonBlocking(PRBool *aNonBlocking)
{
*aNonBlocking = PR_TRUE;
return NS_OK;
}
/////////
// nsISeekableStream implementation
/////////
NS_IMETHODIMP nsStringInputStream::Seek(PRInt32 whence, PRInt32 offset)
{
mLastResult = NS_OK; // reset on a seek.
mEOF = PR_FALSE; // reset on a seek.
PRInt32 fileSize = LengthRemaining();
PRInt32 newPosition=-1;
switch (whence)
{
case NS_SEEK_CUR: newPosition = mOffset + offset; break;
case NS_SEEK_SET: newPosition = offset; break;
case NS_SEEK_END: newPosition = fileSize + offset; break;
}
if (newPosition < 0)
{
newPosition = 0;
mLastResult = NS_FILE_RESULT(PR_FILE_SEEK_ERROR);
}
if (newPosition >= fileSize)
{
newPosition = fileSize;
mEOF = PR_TRUE;
}
mOffset = newPosition;
return NS_OK;
}
NS_IMETHODIMP nsStringInputStream::Tell(PRUint32* outWhere)
{
*outWhere = mOffset;
return NS_OK;
}
NS_IMETHODIMP nsStringInputStream::SetEOF()
{
NS_NOTYETIMPLEMENTED("nsStringInputStream::SetEOF");
return NS_ERROR_NOT_IMPLEMENTED;
}
/////////
// nsIRandomAccessStore implementation
/////////
NS_IMETHODIMP nsStringInputStream::GetAtEOF(PRBool* outAtEOF)
{
*outAtEOF = mEOF;
return NS_OK;
}
NS_IMETHODIMP nsStringInputStream::SetAtEOF(PRBool inAtEOF)
{
mEOF = inAtEOF;
return NS_OK;
}
// Factory method to get an nsInputStream from an nsAString. Result will
// implement nsIStringInputStream and nsIRandomAccessStore
extern "C" NS_COM nsresult
NS_NewStringInputStream(nsIInputStream** aStreamResult,
const nsAString& aStringToRead)
{
NS_PRECONDITION(aStreamResult, "null out ptr");
char* data = ToNewCString(aStringToRead);
if (!data)
return NS_ERROR_OUT_OF_MEMORY;
nsStringInputStream* stream = new nsStringInputStream();
if (! stream) {
nsMemory::Free(data);
return NS_ERROR_OUT_OF_MEMORY;
}
nsresult rv = stream->AdoptData(data, aStringToRead.Length());
if (NS_FAILED(rv)) {
nsMemory::Free(data);
delete stream;
return rv;
}
NS_ADDREF(*aStreamResult = stream);
return NS_OK;
}
// Factory method to get an nsInputStream from an nsAString. Result will
// implement nsIStringInputStream and nsIRandomAccessStore
extern "C" NS_COM nsresult
NS_NewCStringInputStream(nsIInputStream** aStreamResult,
const nsACString& aStringToRead)
{
NS_PRECONDITION(aStreamResult, "null out ptr");
char* data = ToNewCString(aStringToRead);
if (!data)
return NS_ERROR_OUT_OF_MEMORY;
nsStringInputStream* stream = new nsStringInputStream();
if (! stream) {
nsMemory::Free(data);
return NS_ERROR_OUT_OF_MEMORY;
}
nsresult rv = stream->AdoptData(data, aStringToRead.Length());
if (NS_FAILED(rv)) {
nsMemory::Free(data);
delete stream;
return rv;
}
NS_ADDREF(*aStreamResult = stream);
return NS_OK;
}
// Factory method to get an nsInputStream from an nsAString. Result will
// implement nsIStringInputStream and nsIRandomAccessStore
extern "C" NS_COM nsresult
NS_NewCharInputStream(nsIInputStream** aStreamResult,
const char* aStringToRead)
{
NS_PRECONDITION(aStreamResult, "null out ptr");
nsStringInputStream* stream = new nsStringInputStream();
if (! stream)
return NS_ERROR_OUT_OF_MEMORY;
nsresult rv = stream->ShareData(aStringToRead, -1);
if (NS_FAILED(rv)) {
delete stream;
return rv;
}
NS_ADDREF(*aStreamResult = stream);
return NS_OK;
}
// Factory method to get an nsInputStream from an nsAString. Result will
// implement nsIStringInputStream and nsIRandomAccessStore
extern "C" NS_COM nsresult
NS_NewByteInputStream(nsIInputStream** aStreamResult,
const char* aStringToRead,
PRInt32 aLength)
{
NS_PRECONDITION(aStreamResult, "null out ptr");
nsStringInputStream* stream = new nsStringInputStream();
if (! stream)
return NS_ERROR_OUT_OF_MEMORY;
nsresult rv = stream->ShareData(aStringToRead, aLength);
if (NS_FAILED(rv)) {
delete stream;
return rv;
}
NS_ADDREF(*aStreamResult = stream);
return NS_OK;
}
// factory method for constructing a nsStringInputStream object
NS_METHOD
nsStringInputStreamConstructor(nsISupports *outer, REFNSIID iid, void **result)
{
*result = nsnull;
if (outer)
return NS_ERROR_NO_AGGREGATION;
nsStringInputStream *inst;
NS_NEWXPCOM(inst, nsStringInputStream);
if (!inst)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(inst);
nsresult rv = inst->QueryInterface(iid, result);
NS_RELEASE(inst);
return rv;
}