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buffile.h
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1 /*-------------------------------------------------------------------------
2  *
3  * buffile.h
4  * Management of large buffered temporary files.
5  *
6  * The BufFile routines provide a partial replacement for stdio atop
7  * virtual file descriptors managed by fd.c. Currently they only support
8  * buffered access to a virtual file, without any of stdio's formatting
9  * features. That's enough for immediate needs, but the set of facilities
10  * could be expanded if necessary.
11  *
12  * BufFile also supports working with temporary files that exceed the OS
13  * file size limit and/or the largest offset representable in an int.
14  * It might be better to split that out as a separately accessible module,
15  * but currently we have no need for oversize temp files without buffered
16  * access.
17  *
18  * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
19  * Portions Copyright (c) 1994, Regents of the University of California
20  *
21  * src/include/storage/buffile.h
22  *
23  *-------------------------------------------------------------------------
24  */
25 
26 #ifndef BUFFILE_H
27 #define BUFFILE_H
28 
29 #include "storage/sharedfileset.h"
30 
31 /* BufFile is an opaque type whose details are not known outside buffile.c. */
32 
33 typedef struct BufFile BufFile;
34 
35 /*
36  * prototypes for functions in buffile.c
37  */
38 
39 extern BufFile *BufFileCreateTemp(bool interXact);
40 extern void BufFileClose(BufFile *file);
41 extern size_t BufFileRead(BufFile *file, void *ptr, size_t size);
42 extern size_t BufFileWrite(BufFile *file, void *ptr, size_t size);
43 extern int BufFileSeek(BufFile *file, int fileno, off_t offset, int whence);
44 extern void BufFileTell(BufFile *file, int *fileno, off_t *offset);
45 extern int BufFileSeekBlock(BufFile *file, long blknum);
46 extern off_t BufFileSize(BufFile *file);
47 extern long BufFileAppend(BufFile *target, BufFile *source);
48 
50 extern void BufFileExportShared(BufFile *file);
51 extern BufFile *BufFileOpenShared(SharedFileSet *fileset, const char *name);
52 extern void BufFileDeleteShared(SharedFileSet *fileset, const char *name);
53 
54 #endif /* BUFFILE_H */
SharedFileSet * fileset
Definition: buffile.c:81
void BufFileClose(BufFile *file)
Definition: buffile.c:397
int BufFileSeek(BufFile *file, int fileno, off_t offset, int whence)
Definition: buffile.c:676
off_t BufFileSize(BufFile *file)
Definition: buffile.c:811
void BufFileDeleteShared(SharedFileSet *fileset, const char *name)
Definition: buffile.c:349
BufFile * BufFileCreateTemp(bool interXact)
Definition: buffile.c:182
BufFile * BufFileOpenShared(SharedFileSet *fileset, const char *name)
Definition: buffile.c:278
void BufFileExportShared(BufFile *file)
Definition: buffile.c:379
size_t BufFileRead(BufFile *file, void *ptr, size_t size)
Definition: buffile.c:554
long BufFileAppend(BufFile *target, BufFile *source)
Definition: buffile.c:845
const char * name
Definition: encode.c:521
int BufFileSeekBlock(BufFile *file, long blknum)
Definition: buffile.c:778
BufFile * BufFileCreateShared(SharedFileSet *fileset, const char *name)
Definition: buffile.c:245
size_t BufFileWrite(BufFile *file, void *ptr, size_t size)
Definition: buffile.c:601
void BufFileTell(BufFile *file, int *fileno, off_t *offset)
Definition: buffile.c:760