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gecko-dev/xpcom/io/nsStringStream.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim:set ts=4 sts=4 sw=4 cin et: */
/* ***** BEGIN LICENSE BLOCK *****
* 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
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* 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 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
* 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 MPL, 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 MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/**
* Based on original code from nsIStringStream.cpp
*/
#include "nsStringStream.h"
#include "nsStreamUtils.h"
#include "nsReadableUtils.h"
#include "nsISeekableStream.h"
#include "nsISupportsPrimitives.h"
#include "nsInt64.h"
#include "nsCRT.h"
#include "prerror.h"
#include "plstr.h"
#include "nsIClassInfoImpl.h"
//-----------------------------------------------------------------------------
// nsIStringInputStream implementation
//-----------------------------------------------------------------------------
class nsStringInputStream : public nsIStringInputStream
, public nsISeekableStream
, public nsISupportsCString
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIINPUTSTREAM
NS_DECL_NSISTRINGINPUTSTREAM
NS_DECL_NSISEEKABLESTREAM
NS_DECL_NSISUPPORTSPRIMITIVE
NS_DECL_NSISUPPORTSCSTRING
nsStringInputStream()
: mData(nsnull)
, mOffset(0)
, mLength(0)
, mOwned(PR_FALSE)
{}
private:
~nsStringInputStream()
{
if (mData)
Clear();
}
PRInt32 LengthRemaining() const
{
return mLength - mOffset;
}
void Clear()
{
NS_ASSERTION(mData || !mOwned, "bad state");
if (mOwned)
NS_Free(NS_CONST_CAST(char*, mData));
// We're about to get a new string; reset the offset.
mOffset = 0;
}
const char* mData;
PRUint32 mOffset;
PRUint32 mLength;
PRPackedBool mOwned;
};
// This class needs to support threadsafe refcounting since people often
// allocate a string stream, and then read it from a background thread.
NS_IMPL_THREADSAFE_ADDREF(nsStringInputStream)
NS_IMPL_THREADSAFE_RELEASE(nsStringInputStream)
NS_IMPL_QUERY_INTERFACE4_CI(nsStringInputStream,
nsIStringInputStream,
nsIInputStream,
nsISupportsCString,
nsISeekableStream)
NS_IMPL_CI_INTERFACE_GETTER4(nsStringInputStream,
nsIStringInputStream,
nsIInputStream,
nsISupportsCString,
nsISeekableStream)
/////////
// nsISupportsCString implementation
/////////
NS_IMETHODIMP
nsStringInputStream::GetType(PRUint16 *type)
{
*type = TYPE_CSTRING;
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::GetData(nsACString &data)
{
// The stream doesn't have any data when it is closed. We could fake it
// and return an empty string here, but it seems better to keep this return
// value consistent with the behavior of the other 'getter' methods.
NS_ENSURE_TRUE(mData, NS_BASE_STREAM_CLOSED);
data.Assign(mData, mLength);
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::SetData(const nsACString &data)
{
nsACString::const_iterator iter;
data.BeginReading(iter);
return SetData(iter.get(), iter.size_forward());
}
NS_IMETHODIMP
nsStringInputStream::ToString(char **result)
{
// NOTE: This method may result in data loss, so we do not implement it.
return NS_ERROR_NOT_IMPLEMENTED;
}
/////////
// nsIStringInputStream implementation
/////////
NS_IMETHODIMP
nsStringInputStream::SetData(const char *data, PRInt32 dataLen)
{
NS_ENSURE_ARG_POINTER(data);
if (dataLen < 0)
dataLen = strlen(data);
// NOTE: We do not use nsCRT::strndup here because that does not handle
// null bytes in the middle of the given data.
char *copy = NS_STATIC_CAST(char *, NS_Alloc(dataLen));
if (!copy)
return NS_ERROR_OUT_OF_MEMORY;
memcpy(copy, data, dataLen);
return AdoptData(copy, dataLen);
}
NS_IMETHODIMP
nsStringInputStream::AdoptData(char *data, PRInt32 dataLen)
{
NS_ENSURE_ARG_POINTER(data);
if (dataLen < 0)
dataLen = strlen(data);
Clear();
mData = 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();
mData = data;
mLength = dataLen;
mOwned = PR_FALSE;
return NS_OK;
}
/////////
// nsIInputStream implementation
/////////
NS_IMETHODIMP
nsStringInputStream::Close()
{
Clear();
mData = nsnull;
mLength = 0;
mOwned = PR_FALSE;
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::Available(PRUint32 *aLength)
{
NS_ASSERTION(aLength, "null ptr");
if (!mData)
return NS_BASE_STREAM_CLOSED;
*aLength = LengthRemaining();
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::Read(char* aBuf, PRUint32 aCount, PRUint32 *aReadCount)
{
NS_ASSERTION(aBuf, "null ptr");
return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, aReadCount);
}
NS_IMETHODIMP
nsStringInputStream::ReadSegments(nsWriteSegmentFun writer, void *closure,
PRUint32 aCount, PRUint32 *result)
{
NS_ASSERTION(result, "null ptr");
NS_ASSERTION(mLength >= mOffset, "bad stream state");
// We may be at end-of-file
PRUint32 maxCount = mLength - mOffset;
if (maxCount == 0) {
*result = 0;
return NS_OK;
}
NS_ASSERTION(mData, "must have data if maxCount != 0");
if (aCount > maxCount)
aCount = maxCount;
nsresult rv = writer(this, closure, mData + mOffset, 0, aCount, result);
if (NS_SUCCEEDED(rv)) {
NS_ASSERTION(*result <= aCount,
"writer should not write more than we asked it to write");
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, PRInt64 offset)
{
if (!mData)
return NS_BASE_STREAM_CLOSED;
// Compute new stream position. The given offset may be a negative value.
PRInt64 newPos = offset;
switch (whence) {
case NS_SEEK_SET:
break;
case NS_SEEK_CUR:
newPos += (PRInt32) mOffset;
break;
case NS_SEEK_END:
newPos += (PRInt32) mLength;
break;
default:
NS_ERROR("invalid whence");
return NS_ERROR_INVALID_ARG;
}
// mLength is never larger than PR_INT32_MAX due to the way it is assigned.
NS_ENSURE_ARG(newPos >= 0);
NS_ENSURE_ARG(newPos <= (PRInt32) mLength);
mOffset = (PRInt32) newPos;
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::Tell(PRInt64* outWhere)
{
if (!mData)
return NS_BASE_STREAM_CLOSED;
*outWhere = mOffset;
return NS_OK;
}
NS_IMETHODIMP
nsStringInputStream::SetEOF()
{
if (!mData)
return NS_BASE_STREAM_CLOSED;
mLength = mOffset;
return NS_OK;
}
NS_COM nsresult
NS_NewByteInputStream(nsIInputStream** aStreamResult,
const char* aStringToRead, PRInt32 aLength,
nsAssignmentType aAssignment)
{
NS_PRECONDITION(aStreamResult, "null out ptr");
nsStringInputStream* stream = new nsStringInputStream();
if (! stream)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(stream);
nsresult rv;
switch (aAssignment) {
case NS_ASSIGNMENT_COPY:
rv = stream->SetData(aStringToRead, aLength);
break;
case NS_ASSIGNMENT_DEPEND:
rv = stream->ShareData(aStringToRead, aLength);
break;
case NS_ASSIGNMENT_ADOPT:
rv = stream->AdoptData(NS_CONST_CAST(char*, aStringToRead), aLength);
break;
default:
NS_ERROR("invalid assignment type");
rv = NS_ERROR_INVALID_ARG;
}
if (NS_FAILED(rv)) {
NS_RELEASE(stream);
return rv;
}
*aStreamResult = stream;
return NS_OK;
}
NS_COM nsresult
NS_NewStringInputStream(nsIInputStream** aStreamResult,
const nsAString& aStringToRead)
{
char* data = ToNewCString(aStringToRead); // truncates high-order bytes
if (!data)
return NS_ERROR_OUT_OF_MEMORY;
nsresult rv = NS_NewByteInputStream(aStreamResult, data,
aStringToRead.Length(),
NS_ASSIGNMENT_ADOPT);
if (NS_FAILED(rv))
NS_Free(data);
return rv;
}
NS_COM nsresult
NS_NewCStringInputStream(nsIInputStream** aStreamResult,
const nsACString& aStringToRead)
{
nsACString::const_iterator data;
aStringToRead.BeginReading(data);
return NS_NewByteInputStream(aStreamResult, data.get(), data.size_forward(),
NS_ASSIGNMENT_COPY);
}
// factory method for constructing a nsStringInputStream object
NS_METHOD
nsStringInputStreamConstructor(nsISupports *outer, REFNSIID iid, void **result)
{
*result = nsnull;
NS_ENSURE_TRUE(!outer, NS_ERROR_NO_AGGREGATION);
nsStringInputStream *inst = new nsStringInputStream();
if (!inst)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(inst);
nsresult rv = inst->QueryInterface(iid, result);
NS_RELEASE(inst);
return rv;
}
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