private void delete()

in client-adapter/escore/src/main/java/com/alibaba/otter/canal/client/adapter/es/core/service/ESSyncService.java [323:423]
80 lines of code
23 McCabe index (conditional complexity)

    private void delete(ESSyncConfig config, Dml dml) {
        List<Map<String, Object>> dataList = dml.getData();
        if (dataList == null || dataList.isEmpty()) {
            return;
        }
        SchemaItem schemaItem = config.getEsMapping().getSchemaItem();

        for (Map<String, Object> data : dataList) {
            if (data == null || data.isEmpty()) {
                continue;
            }

            ESMapping mapping = config.getEsMapping();

            // ------是主表------
            if (schemaItem.getMainTable().getTableName().equalsIgnoreCase(dml.getTable())) {
                if (mapping.getId() != null) {
                    FieldItem idFieldItem = schemaItem.getIdFieldItem(mapping);
                    // 主键为简单字段
                    if (!idFieldItem.isMethod() && !idFieldItem.isBinaryOp()) {
                        Object idVal = esTemplate.getValFromData(mapping,
                            data,
                            idFieldItem.getFieldName(),
                            idFieldItem.getColumn().getColumnName());

                        if (logger.isTraceEnabled()) {
                            logger.trace("Main table delete es index, destination:{}, table: {}, index: {}, id: {}",
                                config.getDestination(),
                                dml.getTable(),
                                mapping.getIndex(),
                                idVal);
                        }
                        esTemplate.delete(mapping, idVal, null);
                    } else {
                        // ------主键带函数, 查询sql获取主键删除------
                        // FIXME 删除时反查sql为空记录, 无法获获取 id field 值
                        mainTableDelete(config, dml, data);
                    }
                } else {
                    FieldItem pkFieldItem = schemaItem.getIdFieldItem(mapping);
                    if (!pkFieldItem.isMethod() && !pkFieldItem.isBinaryOp()) {
                        Map<String, Object> esFieldData = new LinkedHashMap<>();
                        Object pkVal = esTemplate.getESDataFromDmlData(mapping, data, esFieldData);

                        if (logger.isTraceEnabled()) {
                            logger.trace("Main table delete es index, destination:{}, table: {}, index: {}, pk: {}",
                                config.getDestination(),
                                dml.getTable(),
                                mapping.getIndex(),
                                pkVal);
                        }
                        esFieldData.remove(pkFieldItem.getFieldName());
                        esFieldData.keySet().forEach(key -> esFieldData.put(key, null));
                        esTemplate.delete(mapping, pkVal, esFieldData);
                    } else {
                        // ------主键带函数, 查询sql获取主键删除------
                        mainTableDelete(config, dml, data);
                    }
                }

            }

            // 从表的操作
            for (TableItem tableItem : schemaItem.getAliasTableItems().values()) {
                if (tableItem.isMain()) {
                    continue;
                }
                if (!tableItem.getTableName().equals(dml.getTable())) {
                    continue;
                }

                // 关联条件出现在主表查询条件是否为简单字段
                boolean allFieldsSimple = true;
                for (FieldItem fieldItem : tableItem.getRelationSelectFieldItems()) {
                    if (fieldItem.isMethod() || fieldItem.isBinaryOp()) {
                        allFieldsSimple = false;
                        break;
                    }
                }

                // 所有查询字段均为简单字段
                if (allFieldsSimple) {
                    // 不是子查询
                    if (!tableItem.isSubQuery()) {
                        // ------关联表简单字段更新为null------
                        Map<String, Object> esFieldData = new LinkedHashMap<>();
                        for (FieldItem fieldItem : tableItem.getRelationSelectFieldItems()) {
                            esFieldData.put(Util.cleanColumn(fieldItem.getFieldName()), null);
                        }
                        joinTableSimpleFieldOperation(config, dml, data, tableItem, esFieldData);
                    } else {
                        // ------关联子表简单字段更新------
                        subTableSimpleFieldOperation(config, dml, data, null, tableItem);
                    }
                } else {
                    // ------关联子表复杂字段更新 执行全sql更新es------
                    wholeSqlOperation(config, dml, data, null, tableItem);
                }
            }
        }
    }