gecko-dev/xpcom/io/nsByteBufferInputStream.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* 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.
*/
#ifndef nsByteBufferInputStream_h__
#define nsByteBufferInputStream_h__
#include "nsIByteBufferInputStream.h"
#include "nsCRT.h"
class nsByteBufferInputStream;
////////////////////////////////////////////////////////////////////////////////
class nsByteBufferOutputStream : public nsIOutputStream
{
public:
NS_DECL_ISUPPORTS
// nsIBaseStream methods:
NS_IMETHOD Close(void);
// nsIOutputStream methods:
NS_IMETHOD Write(const char* aBuf, PRUint32 aCount,
PRUint32 *aWriteCount);
NS_IMETHOD WriteFrom(nsIInputStream* fromStream, PRUint32 aCount,
PRUint32 *aWriteCount);
NS_IMETHOD Flush(void);
// nsByteBufferOutputStream methods:
nsByteBufferOutputStream(nsByteBufferInputStream* in);
virtual ~nsByteBufferOutputStream();
protected:
nsByteBufferInputStream* mInputStream;
};
////////////////////////////////////////////////////////////////////////////////
class nsByteBufferInputStream : public nsIByteBufferInputStream
{
public:
NS_DECL_ISUPPORTS
// nsIBaseStream methods:
NS_IMETHOD Close(void);
// nsIInputStream methods:
NS_IMETHOD GetLength(PRUint32 *aLength);
NS_IMETHOD Read(char* aBuf, PRUint32 aCount, PRUint32 *aReadCount);
// nsIByteBufferInputStream methods:
NS_IMETHOD Fill(nsIInputStream* stream, PRUint32 aCount, PRUint32 *aWriteCount);
NS_IMETHOD Fill(const char* aBuf, PRUint32 aCount, PRUint32 *aWriteCount);
// nsByteBufferInputStream methods:
nsByteBufferInputStream(PRBool blocking, PRUint32 size);
virtual ~nsByteBufferInputStream();
friend class nsByteBufferOutputStream;
nsresult Init(void);
nsresult SetEOF(void);
nsresult Drain(void);
PRBool AtEOF() { return mEOF && (mReadCursor == mWriteCursor) && !mFull; }
PRUint32 ReadableAmount() {
if (mReadCursor < mWriteCursor)
return mWriteCursor - mReadCursor;
else if (mReadCursor == mWriteCursor && !mFull)
return 0;
else
return (mLength - mReadCursor) + mWriteCursor;
}
PRUint32 WritableAmount() {
if (mWriteCursor < mReadCursor)
return mWriteCursor - mReadCursor;
else if (mReadCursor == mWriteCursor && mFull)
return 0;
else
return (mLength - mWriteCursor) + mReadCursor;
}
void ReadChunk(char* toBuf, PRUint32 max,
PRUint32 end, PRUint32 *totalRef)
{
NS_ASSERTION(mReadCursor <= end, "bad range");
PRUint32 diff = end - mReadCursor;
PRInt32 amt = PR_MIN(max, diff);
if (amt > 0) {
nsCRT::memcpy(toBuf, &mBuffer[mReadCursor], amt);
#ifdef DEBUG_warren
// nsCRT::memset(&mBuffer[mReadCursor], 0xDD, amt);
#endif
mReadCursor += amt;
*totalRef += amt;
}
}
nsresult WriteChunk(nsIInputStream* in,
PRUint32 end, PRUint32 *totalRef)
{
NS_ASSERTION(mWriteCursor <= end, "bad range");
PRUint32 amt = end - mWriteCursor;
if (amt > 0) {
PRUint32 readAmt;
nsresult rv = in->Read(&mBuffer[mWriteCursor], amt, &readAmt);
if (NS_FAILED(rv)) return rv;
mWriteCursor += readAmt;
*totalRef += readAmt;
}
return NS_OK;
}
protected:
char* mBuffer;
PRUint32 mLength;
PRUint32 mReadCursor;
PRUint32 mWriteCursor;
PRBool mFull;
PRBool mClosed;
PRBool mEOF;
PRBool mBlocking;
};
////////////////////////////////////////////////////////////////////////////////
class nsDummyBufferStream : public nsIInputStream
{
public:
NS_DECL_ISUPPORTS
// nsIBaseStream methods:
NS_IMETHOD Close(void) {
NS_NOTREACHED("nsDummyBufferStream::Close");
return NS_ERROR_FAILURE;
}
// nsIInputStream methods:
NS_IMETHOD GetLength(PRUint32 *aLength) {
*aLength = mLength;
return NS_OK;
}
NS_IMETHOD Read(char* aBuf, PRUint32 aCount, PRUint32 *aReadCount) {
PRUint32 amt = PR_MIN(aCount, mLength);
if (amt > 0) {
nsCRT::memcpy(aBuf, mBuffer, amt);
mBuffer += amt;
mLength -= amt;
}
*aReadCount = amt;
return NS_OK;
}
// nsDummyBufferStream methods:
nsDummyBufferStream(const char* buffer, PRUint32 length)
: mBuffer(buffer), mLength(length) {}
virtual ~nsDummyBufferStream() {}
protected:
const char* mBuffer;
PRUint32 mLength;
};
#endif // nsByteBufferInputStream_h__