xercesxpath.cpp

来自「IBM的解析xml的工具Xerces的源代码」· C++ 代码 · 共 1,455 行 · 第 1/4 页

// ---------------------------------------------------------------------------
XPathScanner::XPathScanner(XMLStringPool* const stringPool)
    : fAndSymbol (0)
    , fOrSymbol(0)
    , fModSymbol(0)
    , fDivSymbol(0)
    , fCommentSymbol(0)
    , fTextSymbol(0)
    , fPISymbol(0)
    , fNodeSymbol(0)
    , fAncestorSymbol(0)
    , fAncestorOrSelfSymbol(0)
    , fAttributeSymbol(0)
    , fChildSymbol(0)
    , fDescendantSymbol(0)
    , fDescendantOrSelfSymbol(0)
    , fFollowingSymbol(0)
    , fFollowingSiblingSymbol(0)
    , fNamespaceSymbol(0)
    , fParentSymbol(0)
    , fPrecedingSymbol(0)
    , fPrecedingSiblingSymbol(0)
    , fSelfSymbol(0)
    , fStringPool(stringPool)
{
    init();
}

// ---------------------------------------------------------------------------
//  XPathScanner: Helper methods
// ---------------------------------------------------------------------------
void XPathScanner::init() {

    fAndSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_AND);
    fOrSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_OR);
    fModSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_MOD);
    fDivSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_DIV);
    fCommentSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_COMMENT);
    fTextSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_TEXT);
    fPISymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_PI);
    fNodeSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_NODE);
    fAncestorSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_ANCESTOR);
    fAncestorOrSelfSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_ANCESTOR_OR_SELF);
    fAttributeSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_ATTRIBUTE);
    fChildSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_CHILD);
    fDescendantSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_DESCENDANT);
    fDescendantOrSelfSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_DESCENDANT_OR_SELF);
    fFollowingSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_FOLLOWING);
    fFollowingSiblingSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_FOLLOWING_SIBLING);
    fNamespaceSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_NAMESPACE);
    fParentSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_PARENT);
    fPrecedingSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_PRECEDING);
    fPrecedingSiblingSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_PRECEDING_SIBLING);
    fSelfSymbol = fStringPool->addOrFind(XPathSymbols::fgSYMBOL_SELF);
}


// ---------------------------------------------------------------------------
//  XPathScanner: Scan methods
// ---------------------------------------------------------------------------
bool XPathScanner::scanExpression(const XMLCh* const data,
                                  int currentOffset,
                                  const int endOffset,
                                  ValueVectorOf<int>* const tokens) {

    bool      starIsMultiplyOperator = false;
    int       nameOffset = -1;
    int       nameHandle = -1;
    int       prefixHandle = -1;
    XMLCh     ch;
    XMLBuffer dataBuffer(128, tokens->getMemoryManager());

    while (true) {

        if (currentOffset == endOffset) {
            break;
        }

        ch = data[currentOffset];

        while (XMLChar1_0::isWhitespace(ch)) {

            if (++currentOffset == endOffset) {
                break;
            }

            ch = data[currentOffset];
        }

        if (currentOffset == endOffset) {
            break;
        }
        //
        // [28] ExprToken ::= '(' | ')' | '[' | ']' | '.' | '..' | '@' | ',' | '::'
        //                  | NameTest | NodeType | Operator | FunctionName
        //                  | AxisName | Literal | Number | VariableReference
        //
        XMLByte chartype = (ch >= 0x80) ? CHARTYPE_NONASCII : fASCIICharMap[ch];

        switch (chartype) {
        case CHARTYPE_OPEN_PAREN:       // '('
            addToken(tokens, XercesXPath::EXPRTOKEN_OPEN_PAREN);
            starIsMultiplyOperator = false;
            ++currentOffset;
            break;
        case CHARTYPE_CLOSE_PAREN:      // ')'
            addToken(tokens, XercesXPath::EXPRTOKEN_CLOSE_PAREN);
            starIsMultiplyOperator = true;
            ++currentOffset;
            break;
        case CHARTYPE_OPEN_BRACKET:     // '['
            addToken(tokens, XercesXPath::EXPRTOKEN_OPEN_BRACKET);
            starIsMultiplyOperator = false;
            ++currentOffset;
            break;
        case CHARTYPE_CLOSE_BRACKET:    // ']'
            addToken(tokens, XercesXPath::EXPRTOKEN_CLOSE_BRACKET);
            starIsMultiplyOperator = true;
            ++currentOffset;
            break;
                //
                // [30] Number ::= Digits ('.' Digits?)? | '.' Digits
                //                                         ^^^^^^^^^^
                //
        case CHARTYPE_PERIOD:           // '.', '..' or '.' Digits
            if (currentOffset + 1 == endOffset) {
                addToken(tokens, XercesXPath::EXPRTOKEN_PERIOD);
                starIsMultiplyOperator = true;
                currentOffset++;
                break;
            }

            ch = data[currentOffset + 1];

            if (ch == chPeriod) {            // '..'
                addToken(tokens, XercesXPath::EXPRTOKEN_DOUBLE_PERIOD);
                starIsMultiplyOperator = true;
                currentOffset += 2;
            } else if (ch >= chDigit_0 && ch <= chDigit_9) {
                addToken(tokens, XercesXPath::EXPRTOKEN_NUMBER);
                starIsMultiplyOperator = true;
                currentOffset = scanNumber(data, endOffset, currentOffset, tokens);
            } else if (ch == chForwardSlash) {
                addToken(tokens, XercesXPath::EXPRTOKEN_PERIOD);
                starIsMultiplyOperator = true;
                currentOffset++;
            } else if (ch == chPipe) { // '|'
                addToken(tokens, XercesXPath::EXPRTOKEN_PERIOD);
                starIsMultiplyOperator = true;
                currentOffset++;
            } else if (XMLChar1_0::isWhitespace(ch)) {
                do {
                    if (++currentOffset == endOffset)
                        break;

                    ch = data[currentOffset];
                } while (XMLChar1_0::isWhitespace(ch));

                if (currentOffset == endOffset || ch == chPipe) {
				    addToken(tokens, XercesXPath::EXPRTOKEN_PERIOD);
                    starIsMultiplyOperator = true;
                    break;
                }
            } else {
                ThrowXMLwithMemMgr(XPathException, XMLExcepts::XPath_InvalidChar, tokens->getMemoryManager());
            }

            break;
        case CHARTYPE_ATSIGN:           // '@'
            addToken(tokens, XercesXPath::EXPRTOKEN_ATSIGN);
            starIsMultiplyOperator = false;
            ++currentOffset;
            break;
        case CHARTYPE_COMMA:            // ','
            addToken(tokens, XercesXPath::EXPRTOKEN_COMMA);
            starIsMultiplyOperator = false;
            ++currentOffset;
            break;
        case CHARTYPE_COLON:            // '::'
            if (++currentOffset == endOffset) {
                return false; // REVISIT
            }
            ch = data[currentOffset];

            if (ch != chColon) {
                return false; // REVISIT
            }
            addToken(tokens, XercesXPath::EXPRTOKEN_DOUBLE_COLON);
            starIsMultiplyOperator = false;
            ++currentOffset;
            break;
        case CHARTYPE_SLASH:            // '/' and '//'
            if (++currentOffset == endOffset) {
                addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_SLASH);
                starIsMultiplyOperator = false;
                break;
            }

            ch = data[currentOffset];

            if (ch == chForwardSlash) { // '//'
                addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_DOUBLE_SLASH);
                starIsMultiplyOperator = false;
                ++currentOffset;
            } else {
                addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_SLASH);
                starIsMultiplyOperator = false;
            }
            break;
        case CHARTYPE_UNION:            // '|'
            addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_UNION);
            starIsMultiplyOperator = false;
            ++currentOffset;
            break;
        case CHARTYPE_PLUS:             // '+'
            addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_PLUS);
            starIsMultiplyOperator = false;
            ++currentOffset;
            break;
        case CHARTYPE_MINUS:            // '-'
            addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_MINUS);
            starIsMultiplyOperator = false;
            ++currentOffset;
            break;
        case CHARTYPE_EQUAL:            // '='
            addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_EQUAL);
            starIsMultiplyOperator = false;
            ++currentOffset;
            break;
        case CHARTYPE_EXCLAMATION:      // '!='
            if (++currentOffset == endOffset) {
                return false; // REVISIT
            }

            ch = data[currentOffset];

            if (ch != chEqual) {
                return false; // REVISIT
            }

            addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_NOT_EQUAL);
            starIsMultiplyOperator = false;
            ++currentOffset;
            break;
        case CHARTYPE_LESS: // '<' and '<='
            if (++currentOffset == endOffset) {
                addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_LESS);
                starIsMultiplyOperator = false;
                break;
            }

            ch = data[currentOffset];

            if (ch == chEqual) { // '<='
                addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_LESS_EQUAL);
                starIsMultiplyOperator = false;
                ++currentOffset;
            } else {
                addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_LESS);
                starIsMultiplyOperator = false;
            }
            break;
        case CHARTYPE_GREATER: // '>' and '>='
            if (++currentOffset == endOffset) {
                addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_GREATER);
                starIsMultiplyOperator = false;
                break;
            }

            ch = data[currentOffset];

            if (ch == chEqual) { // '>='
                addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_GREATER_EQUAL);
                starIsMultiplyOperator = false;
                ++currentOffset;
            } else {
                addToken(tokens, XercesXPath::EXPRTOKEN_OPERATOR_GREATER);
                starIsMultiplyOperator = false;
            }
            break;
        //
        // [29] Literal ::= '"' [^"]* '"' | "'" [^']* "'"
        //
        case CHARTYPE_QUOTE:            // '\"' or '\''
            {
                XMLCh qchar = ch;
                if (++currentOffset == endOffset) {
                    return false; // REVISIT
                }

                ch = data[currentOffset];

                int litOffset = currentOffset;
                while (ch != qchar) {
                    if (++currentOffset == endOffset) {
                        return false; // REVISIT
                    }

                    ch = data[currentOffset];
                }

                addToken(tokens, XercesXPath::EXPRTOKEN_LITERAL);
                starIsMultiplyOperator = true;

                dataBuffer.set(data + litOffset, currentOffset - litOffset);
                tokens->addElement(fStringPool->addOrFind(dataBuffer.getRawBuffer()));
                ++currentOffset;
                break;
            }
        //
        // [30] Number ::= Digits ('.' Digits?)? | '.' Digits
        // [31] Digits ::= [0-9]+
        //
        case CHARTYPE_DIGIT:
            addToken(tokens, XercesXPath::EXPRTOKEN_NUMBER);
            starIsMultiplyOperator = true;
            currentOffset = scanNumber(data, endOffset, currentOffset, tokens);
            break;
        //
        // [36] VariableReference ::= '$' QName
        //
        case CHARTYPE_DOLLAR:
            if (++currentOffset == endOffset) {
                return false; // REVISIT
            }
            nameOffset = currentOffset;
            currentOffset = scanNCName(data, endOffset, currentOffset);

            if (currentOffset == nameOffset) {
                return false; // REVISIT
            }

            if (currentOffset < endOffset) {
                ch = data[currentOffset];
            }
            else {
                ch = 0;
            }

            dataBuffer.set(data + nameOffset, currentOffset - nameOffset);
            nameHandle = fStringPool->addOrFind(dataBuffer.getRawBuffer());
            prefixHandle = -1;

            if (ch == chColon) {

                prefixHandle = nameHandle;
                if (++currentOffset == endOffset) {
                    return false; // REVISIT
                }
                nameOffset = currentOffset;
                currentOffset = scanNCName(data, endOffset, currentOffset);

                if (currentOffset == nameOffset) {
                    return false; // REVISIT
                }

                dataBuffer.set(data + nameOffset, currentOffset - nameOffset);
                nameHandle = fStringPool->addOrFind(dataBuffer.getRawBuffer());
            }
            addToken(tokens, XercesXPath::EXPRTOKEN_VARIABLE_REFERENCE);
            starIsMultiplyOperator = true;
            tokens->addElement(prefixHandle);
            tokens->addElement(nameHandle);
            break;