Source code of Windows XP (NT5)
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/*
* @(#)EncodingStream.cxx 1.0 6/10/97
*
* Copyright (c) 1997 - 1999 Microsoft Corporation. All rights reserved. *
*/
#include "stdinc.h"
#include "core.hxx"
#include "xmlhelper.hxx"
#include "encodingstream.hxx"
#pragma hdrstop
const int EncodingStream::BUFFERSIZE = 4096*sizeof(WCHAR);
//////////////////////////////////////////////////////////////////////////////////
EncodingStream::EncodingStream(IStream * pStream): stream(pStream), encoding(NULL), buf(NULL)
{
#ifdef FUSION_USE_OLD_XML_PARSER_SOURCE
// These objects are sometimes handed out to external clients.
::IncrementComponents();
#endif
pfnWideCharFromMultiByte = NULL;
#ifdef FUSION_USE_OLD_XML_PARSER_SOURCE
pfnWideCharToMultiByte = NULL;
#endif
btotal = bnext = startAt = 0;
lastBuffer = false;
bufsize = 0;
_fEOF = false;
_fReadStream = true;
_fUTF8BOM = false;
//_fTextXML = false;
//_fSetCharset = false;
_dwMode = 0;
codepage = CP_UNDEFINED;
}
//////////////////////////////////////////////////////////////////////////////////
/**
* Builds the EncodingStream for input.
* Reads the first two bytes of the InputStream * in order to make a guess
* as to the character encoding of the file.
*/
IStream * EncodingStream::newEncodingStream(IStream * pStream)
{
EncodingStream * es = NEW (EncodingStream(pStream));
if (es == NULL)
return NULL;
es->AddRef(); // xwu@@ : check this addRef()!
es->isInput = true;
es->buf = NULL;
return es;
}
//////////////////////////////////////////////////////////////////////////////////
EncodingStream::~EncodingStream()
{
if (buf)
delete [] buf;
if (encoding != NULL)
delete encoding;
stream = NULL; // smart pointer
}
//////////////////////////////////////////////////////////////////////////////////
/**
* Reads characters from stream and encode it to Unicode
*/
HRESULT STDMETHODCALLTYPE EncodingStream::Read(void * pv, ULONG cb, ULONG * pcbRead)
{
HRESULT hr;
ULONG num = 0;
if (pcbRead != NULL)
*pcbRead = 0;
if (btotal == 0 && _fEOF) // we already hit EOF - so return right away.
return S_OK;
// Calculate how many UNICODE chars we are allowed to return,
// xiaoyu : which is the same as the number of BYTES read from the file
cb /= sizeof(WCHAR);
checkhr2(prepareForInput(cb));
if (stream && _fReadStream)
{
// btotal = number of bytes already in start of buffer.
if (cb > btotal)
{
hr = stream->Read(buf + btotal, cb - btotal, &num);
// Let's show what we've seen in the debugger so that we can diagnose bad manifests
// more easily. mgrier 12/28/2000
if (::FusionpDbgWouldPrintAtFilterLevel(FUSION_DBG_LEVEL_XMLSTREAM))
{
::FusionpDbgPrintEx(
FUSION_DBG_LEVEL_XMLSTREAM,
"SXS.DLL: Read %lu bytes from XML stream; HRESULT returned = 0x%08lx\n", num, hr);
if (num > 0)
{
::FusionpDbgPrintBlob(
FUSION_DBG_LEVEL_XMLSTREAM,
buf + btotal,
num,
L" ");
}
}
if (hr == E_PENDING && num > 0)
{
// in which case we ignore the error, and continue on !!.
// BUGBUG - this may be a problem.since we are changing the
// return code returned from the stream. This may mean we
// should not ever hand out this stream outside of MSXML.
hr = 0;
}
if (FAILED(hr))
{
return hr;
}
if (btotal == 0 && num == 0)
{
_fEOF = true;
return hr;
}
}
else
{
hr = S_OK;
}
}
else if (btotal == 0)
{
return (lastBuffer) ? S_FALSE : E_PENDING;
}
btotal += num;
UINT b = btotal, utotal = cb;
if (b > cb)
{
// If we have more bytes in our buffer than the caller has
// room for, then only return the number of bytes the caller
// asked for -- otherwise pfnWideCharFromMultiByte will write
// off the end of the caller's buffer.
b = cb;
}
if (pfnWideCharFromMultiByte == NULL) // first read() call
{
checkhr2(autoDetect());
if (pfnWideCharFromMultiByte == NULL) // failed to fully determine encoding
return (lastBuffer) ? S_FALSE : E_PENDING;
b -= bnext;
startAt -= bnext;
}
hr = (this->pfnWideCharFromMultiByte)(&_dwMode, codepage, buf + bnext, &b, (WCHAR *)pv, &utotal);
if (hr != S_OK)
return hr;
if (b == 0 && num == 0 && (stream || lastBuffer))
{
// stream says we're at the end, but pfnWideCharFromMultiByte
// disagrees !!
::FusionpDbgPrintEx(
FUSION_DBG_LEVEL_ERROR,
"SXS.DLL: XML Parser found incomplete encoding\n");
return XML_E_INCOMPLETE_ENCODING;
}
bnext += b;
if (pcbRead != NULL)
*pcbRead = utotal*sizeof(WCHAR);
return (utotal == 0) ? E_PENDING : S_OK;
}
//////////////////////////////////////////////////////////////////////////////////
/**
* Checks the first two/four bytes of the input Stream in order to
* detect UTF-16/UCS-4 or UTF-8 encoding;
* otherwise assume it is UTF-8
* xiaoyu : since only UCS-2 and UTF-8 are support, we do not deal with others...
*/
HRESULT EncodingStream::autoDetect()
{
// wait until we have enough to be sure.
if (btotal < 2)
return S_OK;
unsigned int guess = (((unsigned char)buf[0]) << 8) + ((unsigned char)buf[1]);
HRESULT hr;
if (guess == 0xFEFF || guess == 0xFFFE) // BOM found
{
// wait until we have enough to be sure.
if (btotal < 4)
return S_OK;
unsigned int guess1 = (((unsigned char)buf[2]) << 8) + ((unsigned char)buf[3]);
if (guess == guess1)
{
/*
if (!encoding)
{
static const WCHAR* wchUCS4 = TEXT("UCS-4");
encoding = Encoding::newEncoding(wchUCS4, 5, (0xFFFE == guess), true);
}
bnext = 4;
*/
// FUSION_XML_PARSER does not support UCS4
return XML_E_INVALIDENCODING;
}
else
{
if (!encoding)
{
static const WCHAR* wchUCS2 = L"UCS-2";
encoding = Encoding::newEncoding(wchUCS2, 5, (0xFFFE == guess), true);
}
bnext = 2;
}
if (NULL == encoding)
return E_OUTOFMEMORY;
encoding->littleendian = (0xFFFE == guess);
}
else
{
if (!encoding)
{
encoding = Encoding::newEncoding(); // default encoding : UTF-8
if (NULL == encoding)
return E_OUTOFMEMORY;
}
// In some system, such as win2k, there is BOM 0xEF BB BF for UTF8
if (guess == 0xEFBB)
{
if (btotal < 3)
return S_OK;
if (buf[2] == 0xBF)
_fUTF8BOM = true;
bnext = 3;
}
else
{
encoding->byteOrderMark = false;
}
}
checkhr2(CharEncoder::getWideCharFromMultiByteInfo(encoding, &codepage, &pfnWideCharFromMultiByte, &maxCharSize));
return S_OK;
}
/////////////////////////////////////////////////////////////////////////////////////////
/**
* Switchs the character encoding of the input stream
* Returns:
* S_OK: succeeded, and do not need re-read
* S_FALSE: succeeded, needs to re-read from <code> newPosition </code>
* Otherwise: error code
* Notice:
* This method only works for input stream, newPosition starts with 1
*/
HRESULT EncodingStream::switchEncodingAt(Encoding * newEncoding, int newPosition)
{
// Ignore encoding information in the document when charset information is set from outside
// xwu: fusion xml parsed does not use Charset
//if (_fSetCharset)
// return S_OK;
int l = newPosition - startAt;
if (l < 0 || l > (int)bnext)
{
// out of range
delete newEncoding;
return E_INVALIDARG;
}
UINT newcodepage;
UINT newCharSize;
//
// get and check charset information
//
WideCharFromMultiByteFunc * pfn;
HRESULT hr = CharEncoder::getWideCharFromMultiByteInfo(newEncoding, &newcodepage, &pfn, &newCharSize);
if (hr != S_OK)
{
delete newEncoding;
return E_INVALIDARG;
}
if (codepage == newcodepage)
{
delete newEncoding;
return S_OK;
}
// Now if we are in UCS-2/UCS-4 we cannot switch out of UCS-2/UCS-4 and if we are
// not in UCS-2/UCS-4 we cannot switch into UCS-2/UCS-4.
// Also if UTF-8 BOM is presented, we cannot switch away
if ((codepage != CP_UCS_2 && newcodepage == CP_UCS_2) ||
(codepage == CP_UCS_2 && newcodepage != CP_UCS_2) ||
/* xuw: fusion xml parser only support UTF-8 and UCS-2
(codepage != CP_UCS_4 && newcodepage == CP_UCS_4) ||
(codepage == CP_UCS_4 && newcodepage != CP_UCS_4) ||
*/
(codepage == CP_UTF_8 && newcodepage != CP_UTF_8 && _fUTF8BOM))
{
delete newEncoding;
return E_FAIL;
}
// Ok, then, let's make the switch.
delete encoding;
encoding = newEncoding;
maxCharSize = newCharSize;
codepage = newcodepage;
pfnWideCharFromMultiByte = pfn;
// Because the XML declaration is encoded in UTF-8,
// Mapping input characters to wide characters is one-to-one mapping
if ((int)bnext != l)
{
bnext = l;
return S_FALSE;
}
return S_OK;
}
//////////////////////////////////////////////////////////////////////////////////
// minlen is the number of UNICODE, which is the same number of byte we read from the file
HRESULT EncodingStream::prepareForInput(ULONG minlen)
{
Assert(btotal >= bnext);
btotal -= bnext;
if (bufsize < minlen)
{
BYTE* newbuf = NEW (BYTE[minlen]);
if (newbuf == NULL) {
return E_OUTOFMEMORY;
}
if (buf){
::memcpy(newbuf, buf+bnext, btotal);
delete[] buf;
}
buf = newbuf;
bufsize = minlen;
}
else if (bnext > 0 && btotal > 0)
{
// Shift remaining bytes down to beginning of buffer.
::memmove(buf, buf + bnext, btotal);
}
startAt += bnext;
bnext = 0;
return S_OK;
}
//////////////////////////////////////////////////////////////////////////////////
// xiaoyu : here it assumes that it is a BYTE buffer, not a WCHAR byte, so it can be copied directly
HRESULT EncodingStream::AppendData( const BYTE* buffer, ULONG length, BOOL fLastBuffer)
{
Assert(btotal >= bnext);
lastBuffer = (fLastBuffer != FALSE);
HRESULT hr;
ULONG minlen = length + (btotal - bnext); // make sure we don't loose any data
if (minlen < BUFFERSIZE)
minlen = BUFFERSIZE;
checkhr2( prepareForInput(minlen)); // guarantee enough space in the array
if (length > 0 && buffer != NULL){
// Copy raw data into new buffer.
::memcpy(buf + btotal, buffer, length);
btotal += length;
}
if (pfnWideCharFromMultiByte == NULL) // first AppendData call
{
checkhr2(autoDetect());
}
return hr;
}
//////////////////////////////////////////////////////////////////////////////////
HRESULT EncodingStream::BufferData()
{
HRESULT hr = S_OK;
checkhr2(prepareForInput(0)); // 0 is used just for shift down (so bnext=0).
if (_fEOF) // already hit the end of the stream.
return S_FALSE;
const DWORD BUFSIZE = 4096;
DWORD dwRead = 1;
while (S_OK == hr && dwRead > 0)
{
// if we cannot fit another buffer full, then re-allocate.
DWORD minsize = (btotal+BUFSIZE > bufsize) ? bufsize + BUFSIZE : bufsize;
checkhr2( prepareForInput(minsize)); // make space available.
dwRead = 0;
hr = stream->Read(buf + btotal, BUFSIZE, &dwRead);
btotal += dwRead;
}
if (SUCCEEDED(hr) && dwRead == 0)
{
_fEOF = true;
hr = S_FALSE; // return S_FALSE when at eof.
}
return hr;
}