public void scanComment()

in core/src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlLexer.java [698:914]

• 178 lines of code
• 67 McCabe index (conditional complexity)

    public void scanComment() {
        Token lastToken = this.token;

        if (ch == '-') {
            boolean supportStandardComment = (features & SQLParserFeature.MySQLSupportStandardComment.mask) != 0;
            /*
             * just for tddl test case;
             * test case : MySqlSelectTest_plus_sub_comment.java
             */
            char before_1 = pos == 0 ? ' ' : charAt(pos - 1);
            char next_2 = charAt(pos + 2);
            if (isDigit(next_2)) {
                scanChar();
                token = Token.SUB;
                return;
            } else if (supportStandardComment
                    || ((before_1 == ' ' || (before_1 != '-' && before_1 != '+'))
                    && (next_2 == ' ' || next_2 == EOI || next_2 == '\n'))
            ) {
                // it is comments
            } else if ((before_1 == '-' || before_1 == '+') && next_2 == ' ') {
                throw new ParserException("illegal state. " + info());
            } else {
                if (ch == '-') {
                    scanChar();
                    token = Token.SUB;
                    return;
                } else if (ch == '+') {
                    scanChar();
                    token = Token.PLUS;
                    return;
                }
            }
        } else if (ch != '/') {
            throw new ParserException("illegal state. " + info());
        }

        mark = pos;
        bufPos = 0;
        scanChar();

        // /*+ */
        if (ch == '*') {
            scanChar();
            bufPos++;

            while (ch == ' ') {
                scanChar();
                bufPos++;
            }

            boolean isHint = false;
            int startHintSp = bufPos + 1;
            if (ch == '!' //
                    || ch == '+' // oceanbase hints

                    || ((ch == 'T' && //TDDL hint
                    charAt(pos + 1) == 'D' //
                    && charAt(pos + 2) == 'D' //
                    && charAt(pos + 3) == 'L')
                    && isEnabled(SQLParserFeature.TDDLHint))
            ) {
                isHint = true;
                scanChar();
                bufPos++;
            }

            int starIndex = pos;

            // Dealing with nesting hint.
            int depth = 1;
            while (true) {
                char ch = charAt(starIndex);
                if (ch == '/' && charAt(starIndex + 1) == '*') {
                    starIndex += 2;
                    ch = charAt(starIndex);
                    if (ch == '!' || ch == '+') {
                        ++depth;
                        ++starIndex;
                        continue;
                    }
                } else if (ch == '*' && charAt(starIndex + 1) == '/') {
                    if (0 == --depth) {
                        break;
                    }
                    starIndex += 2;
                    continue;
                }

                if (ch == EOI) {
                    this.token = Token.ERROR;
                    return;
                }
                ++starIndex;
            }

            if (isHint) {
                stringVal = this.subString(mark + startHintSp, starIndex - startHintSp - mark);
                token = Token.HINT;
            } else {
                if (!optimizedForParameterized) {
                    stringVal = this.subString(mark, starIndex + 2 - mark);
                }
                token = Token.MULTI_LINE_COMMENT;
                commentCount++;
                if (keepComments) {
                    stringVal = this.subString(mark, starIndex + 2 - mark);
                    addComment(stringVal);
                }
            }
            pos = starIndex + 2;
            ch = charAt(pos);

            endOfComment = isEOF();

            if (commentHandler != null
                    && commentHandler.handle(lastToken, stringVal)) {
                return;
            }

            if (!isHint && !isAllowComment() && !isSafeComment(stringVal)) {
                throw new NotAllowCommentException();
            }

            return;
        }

        if (ch == '!' && isEnabled(SQLParserFeature.TDDLHint)) { // TDDL HINT
            scanChar();
            bufPos++;

            while (ch == ' ') {
                scanChar();
                bufPos++;
            }

            int startHintSp = bufPos + 1;

            int starIndex = pos;

            for (; ; ) {
                starIndex = text.indexOf('*', starIndex);
                if (starIndex == -1 || starIndex == text.length() - 1) {
                    this.token = Token.ERROR;
                    return;
                }
                if (charAt(starIndex + 1) == '/') {
                    stringVal = this.subString(mark + startHintSp, starIndex - startHintSp - mark);
                    token = Token.HINT;
                    pos = starIndex + 2;
                    ch = charAt(pos);
                    break;
                }
                starIndex++;
            }

            endOfComment = isEOF();

            if (commentHandler != null
                    && commentHandler.handle(lastToken, stringVal)) {
                return;
            }

            if (!isAllowComment() && !isSafeComment(stringVal)) {
                throw new NotAllowCommentException();
            }

            return;
        }

        if (ch == '/' || ch == '-') {
            bufPos++;
            scanChar();

            for (; ; ) {
                if (ch == '\r') {
                    bufPos++;
                    scanChar();
                    if (ch == '\n') {
                        scanChar();
                    }
                    break;
                } else if (ch == EOI) {
                    bufPos++;
                    break;
                }

                if (ch == '\n') {
                    bufPos++;
                    scanChar();
                    break;
                }

                bufPos++;
                scanChar();
            }

            stringVal = subString(mark, bufPos);
            token = Token.LINE_COMMENT;
            commentCount++;
            if (keepComments) {
                addComment(stringVal);
            }

            if (commentHandler != null && commentHandler.handle(lastToken, stringVal)) {
                return;
            }

            endOfComment = isEOF();

            if (!isAllowComment() && (endOfComment || !isSafeComment(stringVal))) {
                throw new NotAllowCommentException();
            }

            return;
        }
    }