private void processTableElement()

in parse/src/main/java/com/alibaba/otter/canal/parse/inbound/mysql/tsdb/MemoryTableMeta.java [190:286]
85 lines of code
25 McCabe index (conditional complexity)

    private void processTableElement(SQLTableElement element, TableMeta tableMeta) {
        if (element instanceof SQLColumnDefinition) {
            FieldMeta fieldMeta = new FieldMeta();
            SQLColumnDefinition column = (SQLColumnDefinition) element;
            String name = getSqlName(column.getName());
            // String charset = getSqlName(column.getCharsetExpr());
            SQLDataType dataType = column.getDataType();
            String dataTypStr = dataType.getName();
            if (StringUtils.equalsIgnoreCase(dataTypStr, "float")) {
                if (dataType.getArguments().size() == 1) {
                    int num = Integer.valueOf(dataType.getArguments().get(0).toString());
                    if (num > 24) {
                        dataTypStr = "double";
                    }
                }
            }

            if (dataType.getArguments().size() > 0) {
                dataTypStr += "(";
                for (int i = 0; i < column.getDataType().getArguments().size(); i++) {
                    if (i != 0) {
                        dataTypStr += ",";
                    }
                    SQLExpr arg = column.getDataType().getArguments().get(i);
                    dataTypStr += arg.toString();
                }
                dataTypStr += ")";
            }

            if (dataType instanceof SQLDataTypeImpl) {
                SQLDataTypeImpl dataTypeImpl = (SQLDataTypeImpl) dataType;
                if (dataTypeImpl.isUnsigned()) {
                    dataTypStr += " unsigned";
                }

                if (dataTypeImpl.isZerofill()) {
                    // mysql default behaiver
                    // 如果设置了zerofill，自动给列添加unsigned属性
                    if (!dataTypeImpl.isUnsigned()) {
                        dataTypStr += " unsigned";
                    }

                    dataTypStr += " zerofill";
                }
            }

            if (column.getDefaultExpr() == null || column.getDefaultExpr() instanceof SQLNullExpr) {
                fieldMeta.setDefaultValue(null);
            } else {
                fieldMeta.setDefaultValue(DruidDdlParser.unescapeQuotaName(getSqlName(column.getDefaultExpr())));
            }

            fieldMeta.setColumnName(name);
            fieldMeta.setColumnType(dataTypStr);
            fieldMeta.setNullable(true);
            List<SQLColumnConstraint> constraints = column.getConstraints();
            for (SQLColumnConstraint constraint : constraints) {
                if (constraint instanceof SQLNotNullConstraint) {
                    fieldMeta.setNullable(false);
                } else if (constraint instanceof SQLNullConstraint) {
                    fieldMeta.setNullable(true);
                } else if (constraint instanceof SQLColumnPrimaryKey) {
                    fieldMeta.setKey(true);
                    fieldMeta.setNullable(false);
                } else if (constraint instanceof SQLColumnUniqueKey) {
                    fieldMeta.setUnique(true);
                }
            }
            tableMeta.addFieldMeta(fieldMeta);
        } else if (element instanceof MySqlPrimaryKey) {
            MySqlPrimaryKey column = (MySqlPrimaryKey) element;
            List<SQLSelectOrderByItem> pks = column.getColumns();
            for (SQLSelectOrderByItem pk : pks) {
                String name = getSqlName(pk.getExpr());
                FieldMeta field = tableMeta.getFieldMetaByName(name);
                field.setKey(true);
                field.setNullable(false);
            }
        } else if (element instanceof MySqlUnique) {
            MySqlUnique column = (MySqlUnique) element;
            List<SQLSelectOrderByItem> uks = column.getColumns();
            // https://github.com/alibaba/canal/issues/5094
            // 处理一下函数索引
            List<String> columnNames = new ArrayList<String>();
            for (SQLSelectOrderByItem uk : uks) {
                SQLExpr sqlName = uk.getExpr();
                columnNames.addAll(getIndexColumnNames(sqlName));
            }
            // uniqe打标
            for (String name : columnNames) {
                FieldMeta field = tableMeta.tryGetFieldMetaByName(name);
                if (field != null) {
                    field.setUnique(true);
                }
            }
        }
    }