/*
* Copyright (c) 2020 Red Hat, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* $Id: //eng/uds-releases/jasper/src/uds/bufferedWriter.h#5 $
*/
#ifndef BUFFERED_WRITER_H
#define BUFFERED_WRITER_H 1
#include "common.h"
#ifdef __KERNEL__
struct dm_bufio_client;
struct ioFactory;
#else
struct ioRegion;
#endif
typedef struct bufferedWriter BufferedWriter;
#ifdef __KERNEL__
/**
* Make a new buffered writer.
*
* @param factory The IOFactory creating the buffered writer
* @param client The dm_bufio_client to write to.
* @param blockLimit The number of blocks that may be written to.
* @param writerPtr The new buffered writer goes here.
*
* @return UDS_SUCCESS or an error code.
**/
int makeBufferedWriter(struct ioFactory *factory,
struct dm_bufio_client *client,
sector_t blockLimit,
BufferedWriter **writerPtr)
__attribute__((warn_unused_result));
#else
/**
* Make a new buffered writer.
*
* @param region The IOregion to write to.
* @param writerPtr The new buffered writer goes here.
*
* @return UDS_SUCCESS or an error code.
**/
int makeBufferedWriter(struct ioRegion *region, BufferedWriter **writerPtr)
__attribute__((warn_unused_result));
#endif
/**
* Free a buffered writer, without flushing.
*
* @param [in] buffer The buffered writer object.
**/
void freeBufferedWriter(BufferedWriter *buffer);
/**
* Append data to buffer, writing as needed.
*
* @param buffer The buffered writer object.
* @param data The data to write.
* @param len The length of the data written.
*
* @return UDS_SUCCESS or an error code.
* The error may reflect previous attempts to write
* or flush the buffer. Once a write or flush error
* occurs it is sticky.
**/
int writeToBufferedWriter(BufferedWriter *buffer, const void *data, size_t len)
__attribute__((warn_unused_result));
/**
* Zero data in the buffer, writing as needed.
*
* @param buffer The buffered writer object.
* @param len The number of zero bytes to write.
*
* @return UDS_SUCCESS or an error code.
* The error may reflect previous attempts to write
* or flush the buffer. Once a write or flush error
* occurs it is sticky.
**/
int writeZerosToBufferedWriter(BufferedWriter *bw, size_t len)
__attribute__((warn_unused_result));
/**
* Flush any partial data from the buffer.
*
* @param buffer The buffered writer object.
*
* @return UDS_SUCCESS or an error code.
* The error may reflect previous attempts to write
* or flush the buffer. Once a write or flush error
* occurs it is sticky.
**/
int flushBufferedWriter(BufferedWriter *buffer)
__attribute__((warn_unused_result));
/**
* Return the size of the remaining space in the buffer (for testing)
*
* @param [in] buffer The buffered writer object.
*
* @return The number of available bytes in the buffer.
**/
size_t spaceRemainingInWriteBuffer(BufferedWriter *buffer)
__attribute__((warn_unused_result));
/**
* Return whether the buffer was ever written to.
*
* @param buffer The buffered writer object.
*
* @return True if at least one call to writeToBufferedWriter
* was made.
**/
bool wasBufferedWriterUsed(const BufferedWriter *buffer)
__attribute__((warn_unused_result));
/**
* Note the buffer has been used.
*
* @param buffer The buffered writer object.
**/
void noteBufferedWriterUsed(BufferedWriter *buffer);
#endif // BUFFERED_WRITER_H