scuffed-code/icu4c/source/common/putilimp.h
2004-11-12 01:11:27 +00:00

279 lines
9.2 KiB
C

/*
******************************************************************************
*
* Copyright (C) 1997-2004, International Business Machines
* Corporation and others. All Rights Reserved.
*
******************************************************************************
*
* FILE NAME : putilimp.h
*
* Date Name Description
* 10/17/04 grhoten Move internal functions from putil.h to this file.
******************************************************************************
*/
#ifndef PUTILIMP_H
#define PUTILIMP_H
#include "unicode/utypes.h"
#include "unicode/putil.h"
/*==========================================================================*/
/* Platform utilities */
/*==========================================================================*/
/**
* Platform utilities isolates the platform dependencies of the
* libarary. For each platform which this code is ported to, these
* functions may have to be re-implemented.
*/
/**
* Floating point utility to determine if a double is Not a Number (NaN).
* @internal
*/
U_INTERNAL UBool U_EXPORT2 uprv_isNaN(double d);
/**
* Floating point utility to determine if a double has an infinite value.
* @internal
*/
U_INTERNAL UBool U_EXPORT2 uprv_isInfinite(double d);
/**
* Floating point utility to determine if a double has a positive infinite value.
* @internal
*/
U_INTERNAL UBool U_EXPORT2 uprv_isPositiveInfinity(double d);
/**
* Floating point utility to determine if a double has a negative infinite value.
* @internal
*/
U_INTERNAL UBool U_EXPORT2 uprv_isNegativeInfinity(double d);
/**
* Floating point utility that returns a Not a Number (NaN) value.
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_getNaN(void);
/**
* Floating point utility that returns an infinite value.
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_getInfinity(void);
/**
* Floating point utility to truncate a double.
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_trunc(double d);
/**
* Floating point utility to calculate the floor of a double.
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_floor(double d);
/**
* Floating point utility to calculate the ceiling of a double.
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_ceil(double d);
/**
* Floating point utility to calculate the absolute value of a double.
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_fabs(double d);
/**
* Floating point utility to calculate the fractional and integer parts of a double.
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_modf(double d, double* pinteger);
/**
* Floating point utility to calculate the remainder of a double divided by another double.
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_fmod(double d, double y);
/**
* Floating point utility to calculate d to the power of exponent (d^exponent).
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_pow(double d, double exponent);
/**
* Floating point utility to calculate 10 to the power of exponent (10^exponent).
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_pow10(int32_t exponent);
/**
* Floating point utility to calculate the maximum value of two doubles.
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_fmax(double d, double y);
/**
* Floating point utility to calculate the minimum value of two doubles.
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_fmin(double d, double y);
/**
* Private utility to calculate the maximum value of two integers.
* @internal
*/
U_INTERNAL int32_t U_EXPORT2 uprv_max(int32_t d, int32_t y);
/**
* Private utility to calculate the minimum value of two integers.
* @internal
*/
U_INTERNAL int32_t U_EXPORT2 uprv_min(int32_t d, int32_t y);
#if U_IS_BIG_ENDIAN
# define uprv_isNegative(number) (*((signed char *)&(number))<0)
#else
# define uprv_isNegative(number) (*((signed char *)&(number)+sizeof(number)-1)<0)
#endif
/**
* Return the largest positive number that can be represented by an integer
* type of arbitrary bit length.
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_maxMantissa(void);
/**
* Return the floor of the log base 10 of a given double.
* This method compensates for inaccuracies which arise naturally when
* computing logs, and always gives the correct value. The parameter
* must be positive and finite.
* (Thanks to Alan Liu for supplying this function.)
*
* @param d the double value to apply the common log function for.
* @return the log of value d.
* @internal
*/
U_INTERNAL int16_t U_EXPORT2 uprv_log10(double d);
/**
* Floating point utility to calculate the logarithm of a double.
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_log(double d);
/**
* Does common notion of rounding e.g. uprv_floor(x + 0.5);
* @param x the double number
* @return the rounded double
* @internal
*/
U_INTERNAL double U_EXPORT2 uprv_round(double x);
#if 0
/**
* Returns the number of digits after the decimal point in a double number x.
*
* @param x the double number
* @return the number of digits after the decimal point in a double number x.
* @internal
*/
/*U_INTERNAL int32_t U_EXPORT2 uprv_digitsAfterDecimal(double x);*/
#endif
/**
* Time zone utilities
*
* Wrappers for C runtime library functions relating to timezones.
* The t_tzset() function (similar to tzset) uses the current setting
* of the environment variable TZ to assign values to three global
* variables: daylight, timezone, and tzname. These variables have the
* following meanings, and are declared in &lt;time.h&gt;.
*
* daylight Nonzero if daylight-saving-time zone (DST) is specified
* in TZ; otherwise, 0. Default value is 1.
* timezone Difference in seconds between coordinated universal
* time and local time. E.g., -28,800 for PST (GMT-8hrs)
* tzname(0) Three-letter time-zone name derived from TZ environment
* variable. E.g., "PST".
* tzname(1) Three-letter DST zone name derived from TZ environment
* variable. E.g., "PDT". If DST zone is omitted from TZ,
* tzname(1) is an empty string.
*
* Notes: For example, to set the TZ environment variable to correspond
* to the current time zone in Germany, you can use one of the
* following statements:
*
* set TZ=GST1GDT
* set TZ=GST+1GDT
*
* If the TZ value is not set, t_tzset() attempts to use the time zone
* information specified by the operating system. Under Windows NT
* and Windows 95, this information is specified in the Control Panel's
* Date/Time application.
* @internal
*/
U_INTERNAL void U_EXPORT2 uprv_tzset(void);
/**
* Difference in seconds between coordinated universal
* time and local time. E.g., -28,800 for PST (GMT-8hrs)
* @return the difference in seconds between coordinated universal time and local time.
* @internal
*/
U_INTERNAL int32_t U_EXPORT2 uprv_timezone(void);
/**
* tzname(0) Three-letter time-zone name derived from TZ environment
* variable. E.g., "PST".
* tzname(1) Three-letter DST zone name derived from TZ environment
* variable. E.g., "PDT". If DST zone is omitted from TZ,
* tzname(1) is an empty string.
* @internal
*/
U_INTERNAL const char* U_EXPORT2 uprv_tzname(int n);
/**
* Get UTC (GMT) time measured in milliseconds since 0:00 on 1/1/1970.
* @return the UTC time measured in milliseconds
* @internal
*/
U_INTERNAL UDate U_EXPORT2 uprv_getUTCtime(void);
/**
* Determine whether a pathname is absolute or not, as defined by the platform.
* @param path Pathname to test
* @return TRUE if the path is absolute
* @internal (ICU 3.0)
*/
U_INTERNAL UBool U_EXPORT2 uprv_pathIsAbsolute(const char *path);
/**
* Maximum value of a (void*) - use to indicate the limit of an 'infinite' buffer.
* In fact, buffer sizes must not exceed 2GB so that the difference between
* the buffer limit and the buffer start can be expressed in an int32_t.
*
* The definition of U_MAX_PTR must fulfill the following conditions:
* - return the largest possible pointer greater than base
* - return a valid pointer according to the machine architecture (AS/400, 64-bit, etc.)
* - avoid wrapping around at high addresses
* - make sure that the returned pointer is not farther from base than 0x7fffffff
*
* @param base The beginning of a buffer to find the maximum offset from
* @internal
*/
#ifndef U_MAX_PTR
# ifdef OS390
# define U_MAX_PTR(base) ((void *)0x7fffffff)
# elif defined(OS400)
/*
* With the provided macro we should never be out of range of a given segment
* (a traditional/typical segment that is). Our segments have 5 bytes for the id
* and 3 bytes for the offset. The key is that the casting takes care of only
* retrieving the offset portion minus x1000. Hence, the smallest offset seen in
* a program is x001000 and when casted to an int would be 0. That's why we can
* only add 0xffefff. Otherwise, we would exceed the segment.
*
* Currently, 16MB is the current addressing limitation on as/400. This macro
* may eventually be changed to use 2GB addressability for the newer version of
* as/400 machines.
*/
# define U_MAX_PTR(base) ((void *)(((char *)base)-((int32_t)(base))+((int32_t)0xffefff)))
# else
# define U_MAX_PTR(base) ((void *)(((char *)(base)+0x7fffffffu) > (char *)(base) ? ((char *)(base)+0x7fffffffu) : (char *)-1))
# endif
#endif
#endif