/*

******************************************************************************

*

*   Copyright (C) 1997-2005, 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 <time.h>.

 *

 *   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

#  if defined(OS390) && !defined(_LP64)

    /* We have 31-bit pointers. */

#    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