// Find
COpcBrowseElement* COpcBrowseElement::Find(const COpcString& cPath)
{
// remove leading separator - if it exists.
COpcString cPrefix = GetSeparator();
COpcString cLocalPath = cPath;
while (cLocalPath.Find(GetSeparator()) == 0)
{
cLocalPath = cLocalPath.SubStr(cPrefix.GetLength());
}
// recursively search children.
OPC_POS pos = m_cChildren.GetHeadPosition();
while (pos != NULL)
{
COpcBrowseElement* pChild = m_cChildren.GetNext(pos);
// check for a child with an exact name match.
if (cLocalPath == pChild->m_cName)
{
return pChild;
}
// check if the path starts with the child name.
COpcString cPrefix = pChild->m_cName + pChild->GetSeparator();
// check for a child with an exact name match plus trailing separator.
if (cLocalPath == cPrefix)
{
return pChild;
}
UINT uIndex = cLocalPath.Find(cPrefix);
// search the child node if there is a match.
if (uIndex == 0)
{
cLocalPath = cLocalPath.SubStr(cPrefix.GetLength());
return pChild->Find(cLocalPath);
}
}
return NULL;
}
// ToTime
static bool ToTime(
const COpcString& cString,
WORD& wHour,
WORD& wMinute,
WORD& wSeconds,
WORD& wFraction
)
{
bool bResult = true;
TRY
{
COpcText cText;
COpcTextReader cReader(cString);
ULong uValue = 0;
// parse hour field.
cText.SetType(COpcText::Delimited);
cText.SetDelims(L":");
if (!cReader.GetNext(cText)) THROW_(bResult, false);
if (!ToUnsigned(cText, uValue, MAX_HOUR, MIN_HOUR, 10)) THROW_(bResult, false);
wHour = (WORD)uValue;
// parse month field.
cText.SetType(COpcText::Delimited);
cText.SetDelims(L":");
if (!cReader.GetNext(cText)) THROW_(bResult, false);
if (!ToUnsigned(cText, uValue, MAX_MINUTE, MIN_MINUTE, 10)) THROW_(bResult, false);
wMinute = (WORD)uValue;
// parse seconds field.
cText.SetType(COpcText::Delimited);
cText.SetDelims(L".");
cText.SetEofDelim();
if (!cReader.GetNext(cText)) THROW_(bResult, false);
if (!ToUnsigned(cText, uValue, MAX_SECOND, MIN_SECOND, 10)) THROW_(bResult, false);
wSeconds = (WORD)uValue;
// parse seconds fraction field.
wFraction = 0;
if (cText.GetDelimChar() == L'.')
{
cText.SetType(COpcText::Delimited);
cText.SetEofDelim();
if (!cReader.GetNext(cText)) THROW_(bResult, false);
// preprocess text.
COpcString cFraction = cText;
// add trailing zeros.
while (cFraction.GetLength() < 3) cFraction += _T("0");
// truncate extra digits.
if (cFraction.GetLength() > 3) cFraction = cFraction.SubStr(0,3);
if (!ToUnsigned(cFraction, uValue, MAX_ULONG, 0, 10))
{
THROW_(bResult, false);
}
// result is in milliseconds.
wFraction = (WORD)uValue;
}
}
CATCH
{
wHour = 0;
wMinute = 0;
wSeconds = 0;
wFraction = 0;
}
return bResult;
}
// ToUnsigned
static bool ToUnsigned(
const COpcString& cString,
ULong& nValue,
ULong nMax,
ULong nMin,
UINT uBase
)
{
bool bResult = true;
TRY
{
COpcText cText;
COpcTextReader cReader(cString);
// extract non-whitespace.
cText.SetType(COpcText::NonWhitespace);
cText.SetEofDelim();
if (!cReader.GetNext(cText))
{
THROW_(bResult, false);
}
COpcString cValue = cText;
nValue = 0;
for (UINT ii = 0; ii < cValue.GetLength(); ii++)
{
UINT uDigit = CharToValue(cValue[ii], uBase);
// invalid digit found.
if (uDigit == -1)
{
bResult = false;
break;
}
// detect overflow
if (nValue > nMax/uBase) THROW_(bResult, false);
// shift result up by base.
nValue *= uBase;
// detect overflow
if (nValue > nMax - uDigit) THROW_(bResult, false);
// add digit.
nValue += uDigit;
}
// detect underflow
if (nMin > nValue) THROW_(bResult, false);
}
CATCH
{
nValue = 0;
}
return bResult;
}
