netcdf-c/include/ncrc.h
Dennis Heimbigner 4636584d5b Revert/Improve nc_create + NC_DISKLESS behavior
re: https://github.com/Unidata/netcdf-c/issues/1154

Inadvertently, the behavior of NC_DISKLESS with nc_create() was
changed in release 4.6.1. Previously, the NC_WRITE flag needed
to be explicitly used with NC_DISKLESS in order to cause the
created file to be persisted to disk.

Additional analyis indicated that the current NC_DISKLESS
implementation was seriously flawed.

This PR attempts to clean up and regularize the situation with
respect to NC_DISKLESS control. One important aspect of diskless
operation is that there are two different notions of write.

1. The file is read-write vs read-only when using the netcdf API.
2. The file is persisted or not to disk at nc_close().

Previously, these two were conflated. The rules now are
as follows.

1. NC_DISKLESS + NC_WRITE means that the file is read/write using the netcdf API
2. NC_DISKLESS + NC_PERSIST means that the file is persisted to a disk file at nc_close.
3. NC_DISKLESS + NC_PERSIST + NC_WRITE means both 1 and 2.

The NC_PERSIST flag is new and takes over the obsolete NC_MPIPOSIX flag.
NC_MPIPOSIX is still defined, but is now an alias for the NC_MPIIO flag.

It is also now the case that for netcdf-4, NC_DISKLESS is independent
of NC_INMEMORY and in fact it is an error to specify both flags
simultaneously.

Finally, the MMAP code was fixed to use NC_PERSIST as well.
Also marked MMAP as deprecated.

Also added a test case to test various combinations of NC_DISKLESS,
NC_PERSIST, and NC_WRITE.

This PR affects a number of files and especially test cases
that used NC_DISKLESS.

Misc. Unrelated fixes
1. fixed some warnings in ncdump/dumplib.c
2018-10-10 13:32:17 -06:00

62 lines
1.9 KiB
C

/*
Copyright (c) 1998-2017 University Corporation for Atmospheric Research/Unidata
See LICENSE.txt for license information.
*/
/*
Common functionality for reading
and accessing rc files (e.g. .daprc).
*/
#ifndef NCRC_H
#define NCRC_H
/* Need these support includes */
#include "ncuri.h"
#include "nclist.h"
#include "ncbytes.h"
typedef struct NCTriple {
char* host; /* combined host:port */
char* key;
char* value;
} NCTriple;
/* collect all the relevant info around the rc file */
typedef struct NCRCinfo {
int ignore; /* if 1, then do not use any rc file */
int loaded; /* 1 => already loaded */
NClist* triples; /* the rc file triple store fields*/
char* rcfile; /* specified rcfile; overrides anything else */
} NCRCinfo;
/* Collect global state info in one place */
typedef struct NCRCglobalstate {
int initialized;
char* tempdir; /* track a usable temp dir */
char* home; /* track $HOME for use in creating $HOME/.oc dir */
NCRCinfo rcinfo; /* Currently only one rc file per session */
} NCRCglobalstate;
extern NCRCglobalstate ncrc_globalstate; /* singleton instance */
/* From drc.c */
/* read and compile the rc file, if any */
extern int NC_rcload(void);
extern char* NC_rclookup(const char* key, const char* hostport);
extern void NC_rcclear(NCRCinfo* info);
extern int NC_set_rcfile(const char* rcfile);
extern int NC_rcfile_insert(const char* key, const char* value, const char* hostport);
/* From dutil.c (Might later move to e.g. nc.h */
extern int NC__testurl(const char* path, char** basenamep);
extern int NC_isLittleEndian(void);
extern char* NC_backslashEscape(const char* s);
extern char* NC_backslashUnescape(const char* esc);
extern char* NC_entityescape(const char* s);
extern int NC_readfile(const char* filename, NCbytes* content);
extern int NC_writefile(const char* filename, size_t size, void* content);
extern char* NC_mktmp(const char* base);
#endif /*NCRC_H*/