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/*-------------------------------------------------------------------------
*
* sync.h
* File synchronization management code.
*
* Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/storage/sync.h
*
*-------------------------------------------------------------------------
*/
#ifndef SYNC_H
#define SYNC_H
#include "storage/relfilenode.h"
/*
* Type of sync request. These are used to manage the set of pending
* requests to call a sync handler's sync or unlink functions at the next
* checkpoint.
*/
typedef enum SyncRequestType
{
SYNC_REQUEST, /* schedule a call of sync function */
SYNC_UNLINK_REQUEST, /* schedule a call of unlink function */
SYNC_FORGET_REQUEST, /* forget all calls for a tag */
SYNC_FILTER_REQUEST /* forget all calls satisfying match fn */
} SyncRequestType;
/*
* Which set of functions to use to handle a given request. The values of
* the enumerators must match the indexes of the function table in sync.c.
*/
typedef enum SyncRequestHandler
{
SYNC_HANDLER_MD = 0,
SYNC_HANDLER_CLOG,
SYNC_HANDLER_COMMIT_TS,
SYNC_HANDLER_MULTIXACT_OFFSET,
SYNC_HANDLER_MULTIXACT_MEMBER,
SYNC_HANDLER_NONE
} SyncRequestHandler;
/*
* A tag identifying a file. Currently it has the members required for md.c's
* usage, but sync.c has no knowledge of the internal structure, and it is
* liable to change as required by future handlers.
*/
typedef struct FileTag
{
int16 handler; /* SyncRequestHandler value, saving space */
int16 forknum; /* ForkNumber, saving space */
RelFileNode rnode;
uint32 segno;
} FileTag;
extern void InitSync(void);
extern void SyncPreCheckpoint(void);
extern void SyncPostCheckpoint(void);
extern void ProcessSyncRequests(void);
extern void RememberSyncRequest(const FileTag *ftag, SyncRequestType type);
extern void EnableSyncRequestForwarding(void);
extern bool RegisterSyncRequest(const FileTag *ftag, SyncRequestType type,
bool retryOnError);
#endif /* SYNC_H */
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