gecko-dev/xpcom/io/nsIStringStream.cpp

486 строки
20 KiB
C++

/* -*- Mode: C++; tab-width: 4; 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.
*/
#include "nsIStringStream.h"
#include "nsIFileStream.h"
#include "prerror.h"
#include "nsFileSpec.h"
#include "plstr.h"
//========================================================================================
class BasicStringImpl
: public nsIOutputStream
, public nsIInputStream
, public nsIRandomAccessStore
//========================================================================================
{
public:
BasicStringImpl()
: mOffset(0)
, mLastResult(NS_OK)
, mEOF(PR_FALSE)
{
NS_INIT_REFCNT();
}
virtual ~BasicStringImpl()
{
}
NS_IMETHOD Seek(PRSeekWhence whence, PRInt32 offset);
NS_IMETHOD Tell(PRIntn* outWhere)
{
*outWhere = mOffset;
return NS_OK;
}
NS_IMETHOD GetAtEOF(PRBool* outAtEOF)
{
*outAtEOF = mEOF;
return NS_OK;
}
NS_IMETHOD SetAtEOF(PRBool inAtEOF)
{
mEOF = inAtEOF;
return NS_OK;
}
NS_IMETHOD GetLength(PRUint32 *aLength)
{
NS_PRECONDITION(aLength != nsnull, "null ptr");
if (!aLength)
return NS_ERROR_NULL_POINTER;
*aLength = length();
return NS_OK;
}
NS_IMETHOD 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 = read(aBuf, aCount);
if (NS_FAILED(mLastResult))
{
*aReadCount = 0;
return mLastResult;
}
*aReadCount = bytesRead;
if (bytesRead < (PRInt32)aCount)
SetAtEOF(PR_TRUE);
return NS_OK;
}
// nsIOutputStream interface
NS_IMETHOD Write(const char* aBuf,
PRUint32 aCount,
PRUint32 *aWriteCount)
{
NS_PRECONDITION(aBuf != nsnull, "null ptr");
NS_PRECONDITION(aWriteCount != nsnull, "null ptr");
if (NS_FAILED(mLastResult))
return mLastResult;
PRInt32 bytesWrit = write(aBuf, aCount);
if (NS_FAILED(mLastResult))
{
*aWriteCount = 0;
return mLastResult;
}
*aWriteCount = bytesWrit;
return NS_OK;
}
NS_IMETHOD Write(nsIInputStream* fromStream, PRUint32 *aWriteCount)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
public:
// nsISupports interface
NS_DECL_ISUPPORTS
NS_IMETHOD Close() { return NS_OK; }
// nsIInputStream interface
NS_IMETHOD Flush() { return NS_OK; }
public:
nsresult get_result() const { return mLastResult; }
protected:
virtual PRInt32 length() const = 0;
virtual PRInt32 read(char* buf, PRUint32 count) = 0;
virtual PRInt32 write(const char*, PRUint32)
{
NS_ASSERTION(PR_FALSE, "Write to a const string");
mLastResult = NS_FILE_RESULT(PR_ILLEGAL_ACCESS_ERROR);
return -1;
}
protected:
PRUint32 mOffset;
nsresult mLastResult;
PRBool mEOF;
}; // class BasicStringImpl
//========================================================================================
class ConstCharImpl
: public BasicStringImpl
//========================================================================================
{
public:
ConstCharImpl(const char* inString)
: mConstString(inString)
, mLength(inString ? strlen(inString) : 0)
{
}
protected:
virtual PRInt32 length() const
{
return mLength;
}
virtual PRInt32 read(char* buf, PRUint32 aCount)
{
PRInt32 maxCount = mLength - mOffset;
if ((PRInt32)aCount > maxCount)
aCount = maxCount;
memcpy(buf, mConstString + mOffset, aCount);
mOffset += aCount;
return aCount;
}
protected:
const char* mConstString;
size_t mLength;
}; // class ConstCharImpl
//========================================================================================
class CharImpl
: public ConstCharImpl
//========================================================================================
{
enum { kAllocQuantum = 256 };
public:
CharImpl(char** inString)
: ConstCharImpl(*inString)
, mString(*inString)
, mAllocLength(mLength + 1)
, mOriginalLength(mLength)
{
if (!mString)
{
mAllocLength += kAllocQuantum;
mString = new char[mAllocLength];
if (!mString)
{
mLastResult = NS_ERROR_OUT_OF_MEMORY;
return;
}
mConstString = mString;
*mString = '\0';
}
}
virtual PRInt32 write(const char* buf, PRUint32 aCount)
{
PRInt32 maxCount = mAllocLength - 1 - mOffset;
if ((PRInt32)aCount > maxCount)
{
do {
maxCount += kAllocQuantum;
} while ((PRInt32)aCount > maxCount);
mAllocLength = maxCount + 1 + mOffset;
char* newString = new char[mAllocLength];
if (!newString)
{
mLastResult = NS_ERROR_OUT_OF_MEMORY;
return 0;
}
strcpy(newString, mString);
delete [] mString;
mString = newString;
mConstString = newString;
}
memcpy(mString + mOffset, buf, aCount);
mOffset += aCount;
if (mOffset > mOriginalLength)
mString[mOffset] = 0;
return aCount;
}
protected:
char*& mString;
size_t mAllocLength;
size_t mOriginalLength;
}; // class CharImpl
//========================================================================================
class ConstStringImpl
: public ConstCharImpl
//========================================================================================
{
public:
ConstStringImpl(const nsString& inString)
: ConstCharImpl(inString.ToNewCString())
{
}
~ConstStringImpl()
{
delete [] (char*)mConstString;
}
protected:
protected:
}; // class ConstStringImpl
//========================================================================================
class StringImpl
: public ConstStringImpl
//========================================================================================
{
public:
StringImpl(nsString& inString)
: ConstStringImpl(inString)
, mString(inString)
{
}
protected:
virtual PRInt32 write(const char* buf, PRUint32 count)
{
// Clone our string as chars
char* cstring = mString.ToNewCString();
// Make a CharImpl and do the write
CharImpl chars(&cstring);
chars.Seek(PR_SEEK_SET, mOffset);
// Get the bytecount and result from the CharImpl
PRInt32 result = chars.write(buf,count);
mLastResult = chars.get_result();
// Set our string to match the new chars
mString = cstring;
// Set our const string also...
delete [] (char*)mConstString;
mConstString = cstring;
return result;
}
protected:
nsString& mString;
}; // class StringImpl
#define SAY_I_IMPLEMENT(classname) \
if (aIID.Equals(classname::GetIID())) \
{ \
*aInstancePtr = (void*)((classname*)this); \
NS_ADDREF_THIS(); \
return NS_OK; \
}
NS_IMPL_RELEASE(BasicStringImpl)
NS_IMPL_ADDREF(BasicStringImpl)
//----------------------------------------------------------------------------------------
NS_IMETHODIMP BasicStringImpl::QueryInterface(REFNSIID aIID, void** aInstancePtr)
//----------------------------------------------------------------------------------------
{
if (!aInstancePtr)
return NS_ERROR_NULL_POINTER;
*aInstancePtr = nsnull;
SAY_I_IMPLEMENT(nsIRandomAccessStore)
SAY_I_IMPLEMENT(nsIOutputStream)
SAY_I_IMPLEMENT(nsIInputStream)
// Note that we derive from two copies of nsIBaseStream (and hence
// of nsISupports), one through
// nsIOutputStream, the other through nsIInputStream. Resolve this
// by giving them a specific one
if (aIID.Equals(((nsIBaseStream*)(nsIOutputStream*)this)->GetIID()))
{
*aInstancePtr = (void*)((nsIBaseStream*)(nsIOutputStream*)this);
NS_ADDREF_THIS();
return NS_OK;
}
if (aIID.Equals(((nsISupports*)(nsIOutputStream*)this)->GetIID()))
{
*aInstancePtr = (void*)((nsISupports*)(nsIOutputStream*)this);
NS_ADDREF_THIS();
return NS_OK;
}
return NS_NOINTERFACE;
} // StringImpl::QueryInterface
//----------------------------------------------------------------------------------------
NS_IMETHODIMP BasicStringImpl::Seek(PRSeekWhence whence, PRInt32 offset)
//----------------------------------------------------------------------------------------
{
mLastResult = NS_OK; // reset on a seek.
mEOF = PR_FALSE; // reset on a seek.
PRInt32 fileSize = length();
PRInt32 newPosition=-1;
switch (whence)
{
case PR_SEEK_CUR: newPosition = mOffset + offset; break;
case PR_SEEK_SET: newPosition = offset; break;
case PR_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;
} // StringImpl::Seek
//----------------------------------------------------------------------------------------
extern "C" NS_COM nsresult NS_NewStringInputStream(
nsISupports** aStreamResult,
const nsString& aStringToRead)
// Factory method to get an nsInputStream from a string. Result will implement all the
// file stream interfaces in nsIFileStream.h
//----------------------------------------------------------------------------------------
{
NS_PRECONDITION(aStreamResult != nsnull, "null ptr");
if (! aStreamResult)
return NS_ERROR_NULL_POINTER;
ConstStringImpl* stream = new ConstStringImpl(aStringToRead);
if (! stream)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(stream);
*aStreamResult = (nsISupports*)(void*)stream;
return NS_OK;
}
//----------------------------------------------------------------------------------------
extern "C" NS_COM nsresult NS_NewStringOutputStream(
nsISupports** aStreamResult,
nsString& aStringToChange)
// Factory method to get an nsOutputStream from a string. Result will implement all the
// file stream interfaces in nsIFileStream.h
//----------------------------------------------------------------------------------------
{
NS_PRECONDITION(aStreamResult != nsnull, "null ptr");
if (! aStreamResult)
return NS_ERROR_NULL_POINTER;
StringImpl* stream = new StringImpl(aStringToChange);
if (! stream)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(stream);
*aStreamResult = (nsISupports*)(void*)stream;
return NS_OK;
}
//----------------------------------------------------------------------------------------
extern "C" NS_COM nsresult NS_NewCharInputStream(
nsISupports** aStreamResult,
const char* aStringToRead)
// Factory method to get an nsInputStream from a string. Result will implement all the
// file stream interfaces in nsIFileStream.h
//----------------------------------------------------------------------------------------
{
NS_PRECONDITION(aStreamResult != nsnull, "null ptr");
if (! aStreamResult)
return NS_ERROR_NULL_POINTER;
ConstCharImpl* stream = new ConstCharImpl(aStringToRead);
if (! stream)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(stream);
*aStreamResult = (nsISupports*)(void*)stream;
return NS_OK;
}
//----------------------------------------------------------------------------------------
extern "C" NS_COM nsresult NS_NewCharOutputStream(
nsISupports** aStreamResult,
char** aStringToChange)
// Factory method to get an nsOutputStream to a string. Result will implement all the
// file stream interfaces in nsIFileStream.h
//----------------------------------------------------------------------------------------
{
NS_PRECONDITION(aStreamResult != nsnull, "null ptr");
NS_PRECONDITION(aStringToChange != nsnull, "null ptr");
if (!aStreamResult || !aStringToChange)
return NS_ERROR_NULL_POINTER;
CharImpl* stream = new CharImpl(aStringToChange);
if (! stream)
return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(stream);
*aStreamResult = (nsISupports*)(void*)stream;
return NS_OK;
}
//----------------------------------------------------------------------------------------
extern "C" NS_COM nsresult NS_NewStringIOStream(
nsISupports** aStreamResult,
nsString& aStringToChange)
// Factory method to get an nsOutputStream to a string. Result will implement all the
// file stream interfaces in nsIFileStream.h
//----------------------------------------------------------------------------------------
{
return NS_NewStringOutputStream(aStreamResult, aStringToChange);
}
//----------------------------------------------------------------------------------------
extern "C" NS_COM nsresult NS_NewCharIOStream(
nsISupports** aStreamResult,
char** aStringToChange)
// Factory method to get an nsOutputStream to a string. Result will implement all the
// file stream interfaces in nsIFileStream.h
//----------------------------------------------------------------------------------------
{
return NS_NewCharOutputStream(aStreamResult, aStringToChange);
}