gecko-dev/xpcom/ds/nsUnicharBuffer.cpp

143 lines
3.8 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#include "nsIUnicharBuffer.h"
#include "nsIUnicharInputStream.h"
#include "nsCRT.h"
#define MIN_BUFFER_SIZE 32
class UnicharBufferImpl : public nsIUnicharBuffer {
public:
UnicharBufferImpl(PRUint32 aBufferSize);
virtual ~UnicharBufferImpl();
NS_DECL_ISUPPORTS
virtual PRInt32 GetLength() const;
virtual PRInt32 GetBufferSize() const;
virtual PRUnichar* GetBuffer() const;
virtual PRBool Grow(PRInt32 aNewSize);
virtual PRInt32 Fill(nsresult* aErrorCode, nsIUnicharInputStream* aStream,
PRInt32 aKeep);
PRUnichar* mBuffer;
PRUint32 mSpace;
PRUint32 mLength;
};
UnicharBufferImpl::UnicharBufferImpl(PRUint32 aBufferSize)
{
if (aBufferSize < MIN_BUFFER_SIZE) {
aBufferSize = MIN_BUFFER_SIZE;
}
mSpace = aBufferSize;
mBuffer = new PRUnichar[aBufferSize];
mLength = 0;
NS_INIT_REFCNT();
}
NS_DEFINE_IID(kUnicharBufferIID, NS_IUNICHAR_BUFFER_IID);
NS_IMPL_ISUPPORTS(UnicharBufferImpl,kUnicharBufferIID)
UnicharBufferImpl::~UnicharBufferImpl()
{
if (nsnull != mBuffer) {
delete[] mBuffer;
mBuffer = nsnull;
}
mLength = 0;
}
PRInt32 UnicharBufferImpl::GetLength() const
{
return mLength;
}
PRInt32 UnicharBufferImpl::GetBufferSize() const
{
return mSpace;
}
PRUnichar* UnicharBufferImpl::GetBuffer() const
{
return mBuffer;
}
PRBool UnicharBufferImpl::Grow(PRInt32 aNewSize)
{
if (PRUint32(aNewSize) < MIN_BUFFER_SIZE) {
aNewSize = MIN_BUFFER_SIZE;
}
PRUnichar* newbuf = new PRUnichar[aNewSize];
if (nsnull != newbuf) {
if (0 != mLength) {
nsCRT::memcpy(newbuf, mBuffer, mLength * sizeof(PRUnichar));
}
delete[] mBuffer;
mBuffer = newbuf;
return PR_TRUE;
}
return PR_FALSE;
}
PRInt32 UnicharBufferImpl::Fill(nsresult* aErrorCode,
nsIUnicharInputStream* aStream,
PRInt32 aKeep)
{
NS_PRECONDITION(nsnull != aStream, "null stream");
NS_PRECONDITION(PRUint32(aKeep) < PRUint32(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
nsCRT::memmove(mBuffer, mBuffer + (mLength - aKeep),
aKeep * sizeof(PRUnichar));
}
// Read in some new data
mLength = aKeep;
PRInt32 amount = mSpace - aKeep;
PRUint32 nb;
NS_ASSERTION(aKeep >= 0, "unsigned madness");
NS_ASSERTION(amount >= 0, "unsigned madness");
*aErrorCode = aStream->Read(mBuffer, (PRUint32)aKeep, (PRUint32)amount, &nb);
if (NS_SUCCEEDED(*aErrorCode)) {
mLength += nb;
}
else
nb = 0;
return nb;
}
NS_BASE nsresult NS_NewUnicharBuffer(nsIUnicharBuffer** aInstancePtrResult,
nsISupports* aOuter,
PRUint32 aBufferSize)
{
if (nsnull != aOuter) {
return NS_ERROR_NO_AGGREGATION;
}
UnicharBufferImpl* it = new UnicharBufferImpl(aBufferSize);
if (nsnull == it) {
return NS_ERROR_OUT_OF_MEMORY;
}
return it->QueryInterface(kUnicharBufferIID, (void **) aInstancePtrResult);
}