ncx.h

一个用来实现偏微分方程中网格的计算库

/*
 *	Copyright 1996, University Corporation for Atmospheric Research
 *	See netcdf/COPYRIGHT file for copying and redistribution conditions.
 */
/* "$Id: ncx.h 2501 2007-11-20 02:33:29Z benkirk $" */

#ifndef _NCX_H_
#define _NCX_H_

/*
 * An external data representation interface.
 *
 * This started out as a general replacement for ONC XDR,
 * specifically, the xdrmem family of functions.
 * 
 * We eventually realized that we could write more portable
 * code if we decoupled any association between the 'C' types
 * and the external types. (XDR has this association between the 'C'
 * types and the external representations, like xdr_int() takes
 * an int argument and goes to an external int representation.) 
 * So, now there is a matrix of functions.
 * 
 */

#include <config.h> /* output of 'configure' */
#include "rnd.h"
#include <stddef.h> /* size_t */
#include <errno.h>
#include <sys/types.h> /* off_t */

/* Define uchar if it is not defined on this system. */
#ifndef HAVE_UCHAR
typedef unsigned char uchar;
#endif

#if defined(_CRAY) && !defined(_CRAYIEEE) && !defined(__crayx1)
#define CRAYFLOAT 1 /* CRAY Floating point */
#elif defined(_SX) && defined(_FLOAT2)	/* NEC SUPER-UX in CRAY mode */
#define CRAYFLOAT 1 /* CRAY Floating point */
#endif


#if defined(DLL_NETCDF) /* define when library is a DLL */
#include <io.h>
#define lseek _lseeki64
#define off_t __int64
#endif	/* defined(DLL_NETCDF) */

/*
 * The integer return code for the conversion routines
 * is 0 (ENOERR) when no error occured, or NC_ERANGE as appropriate
 * for an overflow conversion.
 */
#ifndef ENOERR
#define ENOERR 0
#endif
#ifndef NC_ERANGE
#define NC_ERANGE (-60) /* N.B. must match value in netcdf.h */
#endif
#ifndef NC_ENOMEM
#define NC_ENOMEM (-61) /* N.B. must match value in netcdf.h */
#endif


/*
 * External sizes of the primitive elements.
 */
#define X_SIZEOF_CHAR		1
#define X_SIZEOF_SHORT		2
#define X_SIZEOF_INT		4	/* xdr_int */
#if 0
#define X_SIZEOF_LONG		8 */	/* xdr_long_long */
#endif
#define X_SIZEOF_FLOAT		4
#define X_SIZEOF_DOUBLE		8

/*
 * For now, netcdf is limited to 32 bit sizes,
 * If compiled with support for "large files", then
 * netcdf will use a 64 bit off_t and it can then write a file
 * using 64 bit offsets. 
 *  see also X_SIZE_MAX, X_OFF_MAX below
 */
#define X_SIZEOF_OFF_T		(sizeof(off_t))
#define X_SIZEOF_SIZE_T		X_SIZEOF_INT

/*
 * limits of the external representation
 */
#define X_SCHAR_MIN	(-128)
#define X_SCHAR_MAX	127
#define X_UCHAR_MAX	255U
#define X_SHORT_MIN	(-32768)
#define X_SHRT_MIN	X_SHORT_MIN	/* alias compatible with limits.h */
#define X_SHORT_MAX	32767
#define X_SHRT_MAX	X_SHORT_MAX	/* alias compatible with limits.h */
#define X_USHORT_MAX	65535U
#define X_USHRT_MAX	X_USHORT_MAX	/* alias compatible with limits.h */
#define X_INT_MIN	(-2147483647-1)
#define X_INT_MAX	2147483647
#define X_UINT_MAX	4294967295U
#define X_FLOAT_MAX	3.402823466e+38f
#define X_FLOAT_MIN	(-X_FLOAT_MAX)
#define X_FLT_MAX	X_FLOAT_MAX	/* alias compatible with limits.h */
#if CRAYFLOAT
/* ldexp(1. - ldexp(.5 , -46), 1024) */
#define X_DOUBLE_MAX    1.79769313486230e+308
#else
/* scalb(1. - scalb(.5 , -52), 1024) */
#define X_DOUBLE_MAX	1.7976931348623157e+308 
#endif
#define X_DOUBLE_MIN	(-X_DOUBLE_MAX)
#define X_DBL_MAX	X_DOUBLE_MAX	/* alias compatible with limits.h */

#define X_SIZE_MAX	X_UINT_MAX
#define X_OFF_MAX	X_INT_MAX


/* Begin ncx_len */

/*
 * ncx_len_xxx() interfaces are defined as macros below, 
 * These give the length of an array of nelems of the type.
 * N.B. The 'char' and 'short' interfaces give the X_ALIGNED length.
 */
#define X_ALIGN			4	/* a.k.a. BYTES_PER_XDR_UNIT */

#define ncx_len_char(nelems) \
	_RNDUP((nelems), X_ALIGN)

#define ncx_len_short(nelems) \
	(((nelems) + (nelems)%2)  * X_SIZEOF_SHORT)

#define ncx_len_int(nelems) \
	((nelems) * X_SIZEOF_INT)

#define ncx_len_long(nelems) \
	((nelems) * X_SIZEOF_LONG)

#define ncx_len_float(nelems) \
	((nelems) * X_SIZEOF_FLOAT)

#define ncx_len_double(nelems) \
	((nelems) * X_SIZEOF_DOUBLE)

/* End ncx_len */

#if __CHAR_UNSIGNED__
	/* 'char' is unsigned, declare ncbyte as 'signed char' */
typedef signed char schar;

#else
	/* 'char' is signed */
typedef signed char schar;

#endif	/* __CHAR_UNSIGNED__ */

/*
 * Primitive numeric conversion functions.
 * The `put' functions convert from native internal
 * type to the external type, while the `get' functions
 * convert from the external to the internal.
 *
 * These take the form
 *	int ncx_get_{external_type}_{internal_type}(
 *		const void *xp,
 *		internal_type *ip
 *	);
 *	int ncx_put_{external_type}_{internal_type}(
 *		void *xp,
 *		const internal_type *ip
 *	);
 * where
 *	`external_type' and `internal_type' chosen from
		schar
		uchar
		short
		ushort
		int
		uint
		long
		ulong
		float
		double
 *
 * Not all combinations make sense.
 * We may not implement all combinations that make sense.
 * The netcdf functions that use this ncx interface don't
 * use these primitive conversion functions. They use the
 * aggregate conversion functions declared below.
 *
 * Storage for a single element of external type is at the `void * xp'
 * argument.
 *
 * Storage for a single element of internal type is at `ip' argument.
 *
 * These functions return 0 (ENOERR) when no error occured,
 * or NC_ERANGE when the value being converted is too large.
 * When NC_ERANGE occurs, an undefined (implementation dependent)
 * conversion may have occured.
 *
 * Note that loss of precision may occur silently.
 *
 */

#if 0
extern int
ncx_get_schar_schar(const void *xp, schar *ip);
extern int
ncx_get_schar_uchar(const void *xp, uchar *ip);
extern int
ncx_get_schar_short(const void *xp, short *ip);
extern int
ncx_get_schar_int(const void *xp, int *ip);
extern int
ncx_get_schar_long(const void *xp, long *ip);
extern int
ncx_get_schar_float(const void *xp, float *ip);
extern int
ncx_get_schar_double(const void *xp, double *ip);

extern int
ncx_put_schar_schar(void *xp, const schar *ip);
extern int
ncx_put_schar_uchar(void *xp, const uchar *ip);
extern int
ncx_put_schar_short(void *xp, const short *ip);
extern int
ncx_put_schar_int(void *xp, const int *ip);
extern int
ncx_put_schar_long(void *xp, const long *ip);
extern int
ncx_put_schar_float(void *xp, const float *ip);
extern int
ncx_put_schar_double(void *xp, const double *ip);
#endif
 

extern int
ncx_get_short_schar(const void *xp, schar *ip);
extern int
ncx_get_short_uchar(const void *xp, uchar *ip);
extern int
ncx_get_short_short(const void *xp, short *ip);
extern int
ncx_get_short_int(const void *xp, int *ip);
extern int
ncx_get_short_long(const void *xp, long *ip);
extern int
ncx_get_short_float(const void *xp, float *ip);
extern int
ncx_get_short_double(const void *xp, double *ip);

extern int
ncx_put_short_schar(void *xp, const schar *ip);
extern int
ncx_put_short_uchar(void *xp, const uchar *ip);
extern int
ncx_put_short_short(void *xp, const short *ip);
extern int
ncx_put_short_int(void *xp, const int *ip);
extern int
ncx_put_short_long(void *xp, const long *ip);
extern int
ncx_put_short_float(void *xp, const float *ip);
extern int
ncx_put_short_double(void *xp, const double *ip);
 

extern int
ncx_get_int_schar(const void *xp, schar *ip);
extern int
ncx_get_int_uchar(const void *xp, uchar *ip);
extern int
ncx_get_int_short(const void *xp, short *ip);
extern int
ncx_get_int_int(const void *xp, int *ip);
extern int
ncx_get_int_long(const void *xp, long *ip);
extern int
ncx_get_int_float(const void *xp, float *ip);
extern int
ncx_get_int_double(const void *xp, double *ip);

extern int
ncx_put_int_schar(void *xp, const schar *ip);
extern int
ncx_put_int_uchar(void *xp, const uchar *ip);
extern int
ncx_put_int_short(void *xp, const short *ip);
extern int
ncx_put_int_int(void *xp, const int *ip);
extern int
ncx_put_int_long(void *xp, const long *ip);
extern int
ncx_put_int_float(void *xp, const float *ip);
extern int
ncx_put_int_double(void *xp, const double *ip);
 

extern int
ncx_get_float_schar(const void *xp, schar *ip);
extern int
ncx_get_float_uchar(const void *xp, uchar *ip);
extern int
ncx_get_float_short(const void *xp, short *ip);
extern int
ncx_get_float_int(const void *xp, int *ip);
extern int
ncx_get_float_long(const void *xp, long *ip);
extern int
ncx_get_float_float(const void *xp, float *ip);
extern int
ncx_get_float_double(const void *xp, double *ip);

extern int
ncx_put_float_schar(void *xp, const schar *ip);
extern int
ncx_put_float_uchar(void *xp, const uchar *ip);
extern int
ncx_put_float_short(void *xp, const short *ip);
extern int
ncx_put_float_int(void *xp, const int *ip);
extern int
ncx_put_float_long(void *xp, const long *ip);
extern int
ncx_put_float_float(void *xp, const float *ip);
extern int
ncx_put_float_double(void *xp, const double *ip);
 

extern int
ncx_get_double_schar(const void *xp, schar *ip);
extern int
ncx_get_double_uchar(const void *xp, uchar *ip);
extern int