/**
* Relational pipes (library)
* Copyright © 2022 František Kučera (Frantovo.cz, GlobalCode.info)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the:
* - GNU Lesser General Public License as published by the Free Software Foundation;
* version 3 of the License or (at your option)
* - GNU General Public License as published by the Free Software Foundation;
* version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
namespace relpipe {
namespace writer {
/**
* Relational output might be – and usually is – buffered
* i.e. relational data are written to a buffer and flushed later and sent to the actual output stream.
*
* Through these modes we can control when the flush is done.
*
* Recommendation:
* - batch processing: AUTO
* - interactive processing: RECORD
* - tools should not set the mode explicitly unless asked by the user or unles specific mode is obvious for given task;
* then ENVIRONMENT mode is the initial one and it defaults to AUTO when user has not set the environmental variable
*/
enum class BufferingMode {
/**
* Output buffer is not explicitly flushed, it is written when full.
*/
AUTO,
/**
* Mode is determined by the environmental variable RELPIPE_WRITER_BUFFERING_MODE.
* If value is missing or has invalid value, AUTO is used as default.
*/
ENVIRONMENT,
/**
* Output buffer is flushed at least at the end of each relation.
*/
RELATION,
/**
* Output buffer is flushed at least at the end of each record.
*/
RECORD,
/**
* Output buffer is flushed at least at the end of each attribute.
*/
ATTRIBUTE
};
}
}