1 files changed, 56 insertions, 0 deletions
diff --git a/src/include/storage/buffile.h b/src/include/storage/buffile.h
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+++ b/src/include/storage/buffile.h
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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) 1996-2021, 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 void 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,
+								  int mode);
+extern void BufFileDeleteShared(SharedFileSet *fileset, const char *name);
+extern void BufFileTruncateShared(BufFile *file, int fileno, off_t offset);
+
+#endif							/* BUFFILE_H */