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/*-------------------------------------------------------------------------
*
* buffile.h
* Management of large buffered temporary files.
*
* The BufFile routines provide a partial replacement for stdio atop
* virtual file descriptors managed by fd.c. Currently they only support
* buffered access to a virtual file, without any of stdio's formatting
* features. That's enough for immediate needs, but the set of facilities
* could be expanded if necessary.
*
* BufFile also supports working with temporary files that exceed the OS
* file size limit and/or the largest offset representable in an int.
* It might be better to split that out as a separately accessible module,
* but currently we have no need for oversize temp files without buffered
* access.
*
* Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/storage/buffile.h
*
*-------------------------------------------------------------------------
*/
#ifndef BUFFILE_H
#define BUFFILE_H
#include "storage/sharedfileset.h"
/* BufFile is an opaque type whose details are not known outside buffile.c. */
typedef struct BufFile BufFile;
/*
* prototypes for functions in buffile.c
*/
extern BufFile *BufFileCreateTemp(bool interXact);
extern void BufFileClose(BufFile *file);
extern size_t BufFileRead(BufFile *file, void *ptr, size_t size);
extern size_t BufFileWrite(BufFile *file, void *ptr, size_t size);
extern int BufFileSeek(BufFile *file, int fileno, off_t offset, int whence);
extern void BufFileTell(BufFile *file, int *fileno, off_t *offset);
extern int BufFileSeekBlock(BufFile *file, long blknum);
extern int64 BufFileSize(BufFile *file);
extern long BufFileAppend(BufFile *target, BufFile *source);
extern BufFile *BufFileCreateShared(SharedFileSet *fileset, const char *name);
extern void BufFileExportShared(BufFile *file);
extern BufFile *BufFileOpenShared(SharedFileSet *fileset, const char *name);
extern void BufFileDeleteShared(SharedFileSet *fileset, const char *name);
#endif /* BUFFILE_H */
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