/* -------------------------------------------------------------------------
 *
 * buffile.h
 *	  Management of large buffered files, primarily 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) 1996-2012, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/storage/buf/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);
extern long BufFileAppend(BufFile *target, BufFile *source);
#endif /* BUFFILE_H */