/*------------------------------------------------------------------------- * * be-fsstubs.c *	  support for filesystem operations on large objects * * Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION *	  $Header: /usr/local/cvsroot/pgsql/src/backend/libpq/be-fsstubs.c,v 1.35 1999/06/04 21:13:38 tgl Exp $ * * NOTES *	  This should be moved to a more appropriate place.  It is here *	  for lack of a better place. * *	  Builtin functions for open/close/read/write operations on large objects. * *	  These functions operate in a private GlobalMemoryContext, which means *	  that large object descriptors hang around until we destroy the context. *	  That happens in lo_commit().  It'd be possible to prolong the lifetime *	  of the context so that LO FDs are good across transactions (for example, *	  we could release the context only if we see that no FDs remain open). *	  But we'd need additional state in order to do the right thing at the *	  end of an aborted transaction.  FDs opened during an aborted xact would *	  still need to be closed, since they might not be pointing at valid *	  relations at all.  For now, we'll stick with the existing documented *	  semantics of LO FDs: they're only good within a transaction. * *------------------------------------------------------------------------- */#include <fcntl.h>#include <sys/types.h>#include <sys/stat.h>#include <unistd.h>#include <string.h>#include <postgres.h>#include <lib/dllist.h>#include <libpq/libpq.h>#include <libpq/libpq-fs.h>#include <nodes/nodes.h>#include <utils/memutils.h>#include <lib/fstack.h>#include <utils/mcxt.h>#include <catalog/pg_shadow.h>	/* for superuser() */#include <storage/fd.h>			/* for O_ */#include <storage/large_object.h>#include <libpq/be-fsstubs.h>/* [PA] is Pascal Andr