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db_include/storage/sharedfileset.h

@@ -0,0 +1,47 @@
+/*-------------------------------------------------------------------------
+ *
+ * sharedfileset.h
+ *	  Shared temporary file management.
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/storage/sharedfileset.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SHAREDFILESET_H
+#define SHAREDFILESET_H
+
+#include "storage/dsm.h"
+#include "storage/fd.h"
+#include "storage/spin.h"
+
+/*
+ * A set of temporary files that can be shared by multiple backends.
+ */
+typedef struct SharedFileSet
+{
+	pid_t		creator_pid;	/* PID of the creating process */
+	uint32		number;			/* per-PID identifier */
+	slock_t		mutex;			/* mutex protecting the reference count */
+	int			refcnt;			/* number of attached backends */
+	int			ntablespaces;	/* number of tablespaces to use */
+	Oid			tablespaces[8]; /* OIDs of tablespaces to use. Assumes that
+								 * it's rare that there more than temp
+								 * tablespaces. */
+} SharedFileSet;
+
+extern void SharedFileSetInit(SharedFileSet *fileset, dsm_segment *seg);
+extern void SharedFileSetAttach(SharedFileSet *fileset, dsm_segment *seg);
+extern File SharedFileSetCreate(SharedFileSet *fileset, const char *name);
+extern File SharedFileSetOpen(SharedFileSet *fileset, const char *name,
+							  int mode);
+extern bool SharedFileSetDelete(SharedFileSet *fileset, const char *name,
+								bool error_on_failure);
+extern void SharedFileSetDeleteAll(SharedFileSet *fileset);
+extern void SharedFileSetUnregister(SharedFileSet *input_fileset);
+
+#endif