1 /*

     2 ******************************************************************************

     3 *

     4 *   Copyright (C) 1997-2005, International Business Machines

     5 *   Corporation and others.  All Rights Reserved.

     6 *

     7 ******************************************************************************

     8 *

     9 *  FILE NAME : putilimp.h

    10 *

    11 *   Date        Name        Description

    12 *   10/17/04    grhoten     Move internal functions from putil.h to this file.

    13 ******************************************************************************

    14 */

    15 

    16 #ifndef PUTILIMP_H

    17 #define PUTILIMP_H

    18 

    19 #include "unicode/utypes.h"

    20 #include "unicode/putil.h"

    21 

    22 /*==========================================================================*/

    23 /* Platform utilities                                                       */

    24 /*==========================================================================*/

    25 

    26 /**

    27  * Platform utilities isolates the platform dependencies of the

    28  * libarary.  For each platform which this code is ported to, these

    29  * functions may have to be re-implemented.

    30  */

    31 

    32 /**

    33  * Floating point utility to determine if a double is Not a Number (NaN).

    34  * @internal

    35  */

    36 U_INTERNAL UBool   U_EXPORT2 uprv_isNaN(double d);

    37 /**

    38  * Floating point utility to determine if a double has an infinite value.

    39  * @internal

    40  */

    41 U_INTERNAL UBool   U_EXPORT2 uprv_isInfinite(double d);

    42 /**

    43  * Floating point utility to determine if a double has a positive infinite value.

    44  * @internal

    45  */

    46 U_INTERNAL UBool   U_EXPORT2 uprv_isPositiveInfinity(double d);

    47 /**

    48  * Floating point utility to determine if a double has a negative infinite value.

    49  * @internal

    50  */

    51 U_INTERNAL UBool   U_EXPORT2 uprv_isNegativeInfinity(double d);

    52 /**

    53  * Floating point utility that returns a Not a Number (NaN) value.

    54  * @internal

    55  */

    56 U_INTERNAL double  U_EXPORT2 uprv_getNaN(void);

    57 /**

    58  * Floating point utility that returns an infinite value.

    59  * @internal

    60  */

    61 U_INTERNAL double  U_EXPORT2 uprv_getInfinity(void);

    62 

    63 /**

    64  * Floating point utility to truncate a double.

    65  * @internal

    66  */

    67 U_INTERNAL double  U_EXPORT2 uprv_trunc(double d);

    68 /**

    69  * Floating point utility to calculate the floor of a double.

    70  * @internal

    71  */

    72 U_INTERNAL double  U_EXPORT2 uprv_floor(double d);

    73 /**

    74  * Floating point utility to calculate the ceiling of a double.

    75  * @internal

    76  */

    77 U_INTERNAL double  U_EXPORT2 uprv_ceil(double d);

    78 /**

    79  * Floating point utility to calculate the absolute value of a double.

    80  * @internal

    81  */

    82 U_INTERNAL double  U_EXPORT2 uprv_fabs(double d);

    83 /**

    84  * Floating point utility to calculate the fractional and integer parts of a double.

    85  * @internal

    86  */

    87 U_INTERNAL double  U_EXPORT2 uprv_modf(double d, double* pinteger);

    88 /**

    89  * Floating point utility to calculate the remainder of a double divided by another double.

    90  * @internal

    91  */

    92 U_INTERNAL double  U_EXPORT2 uprv_fmod(double d, double y);

    93 /**

    94  * Floating point utility to calculate d to the power of exponent (d^exponent).

    95  * @internal

    96  */

    97 U_INTERNAL double  U_EXPORT2 uprv_pow(double d, double exponent);

    98 /**

    99  * Floating point utility to calculate 10 to the power of exponent (10^exponent).

   100  * @internal

   101  */

   102 U_INTERNAL double  U_EXPORT2 uprv_pow10(int32_t exponent);

   103 /**

   104  * Floating point utility to calculate the maximum value of two doubles.

   105  * @internal

   106  */

   107 U_INTERNAL double  U_EXPORT2 uprv_fmax(double d, double y);

   108 /**

   109  * Floating point utility to calculate the minimum value of two doubles.

   110  * @internal

   111  */

   112 U_INTERNAL double  U_EXPORT2 uprv_fmin(double d, double y);

   113 /**

   114  * Private utility to calculate the maximum value of two integers.

   115  * @internal

   116  */

   117 U_INTERNAL int32_t U_EXPORT2 uprv_max(int32_t d, int32_t y);

   118 /**

   119  * Private utility to calculate the minimum value of two integers.

   120  * @internal

   121  */

   122 U_INTERNAL int32_t U_EXPORT2 uprv_min(int32_t d, int32_t y);

   123 

   124 #if U_IS_BIG_ENDIAN

   125 #   define uprv_isNegative(number) (*((signed char *)&(number))<0)

   126 #else

   127 #   define uprv_isNegative(number) (*((signed char *)&(number)+sizeof(number)-1)<0)

   128 #endif

   129 

   130 /**

   131  * Return the largest positive number that can be represented by an integer

   132  * type of arbitrary bit length.

   133  * @internal

   134  */

   135 U_INTERNAL double  U_EXPORT2 uprv_maxMantissa(void);

   136 

   137 /**

   138  * Return the floor of the log base 10 of a given double.

   139  * This method compensates for inaccuracies which arise naturally when

   140  * computing logs, and always gives the correct value.  The parameter

   141  * must be positive and finite.

   142  * (Thanks to Alan Liu for supplying this function.)

   143  *

   144  * @param d the double value to apply the common log function for.

   145  * @return the log of value d.

   146  * @internal

   147  */

   148 U_INTERNAL int16_t  U_EXPORT2 uprv_log10(double d);

   149 

   150 /**

   151  * Floating point utility to calculate the logarithm of a double.

   152  * @internal

   153  */

   154 U_INTERNAL double  U_EXPORT2 uprv_log(double d);

   155 

   156 /**

   157  * Does common notion of rounding e.g. uprv_floor(x + 0.5);

   158  * @param x the double number

   159  * @return the rounded double

   160  * @internal

   161  */

   162 U_INTERNAL double  U_EXPORT2 uprv_round(double x);

   163 

   164 #if 0

   165 /**

   166  * Returns the number of digits after the decimal point in a double number x.

   167  *

   168  * @param x the double number

   169  * @return the number of digits after the decimal point in a double number x.

   170  * @internal

   171  */

   172 /*U_INTERNAL int32_t  U_EXPORT2 uprv_digitsAfterDecimal(double x);*/

   173 #endif

   174 

   175 /**

   176  * Time zone utilities

   177  *

   178  * Wrappers for C runtime library functions relating to timezones.

   179  * The t_tzset() function (similar to tzset) uses the current setting 

   180  * of the environment variable TZ to assign values to three global 

   181  * variables: daylight, timezone, and tzname. These variables have the 

   182  * following meanings, and are declared in <time.h>.

   183  *

   184  *   daylight   Nonzero if daylight-saving-time zone (DST) is specified

   185  *              in TZ; otherwise, 0. Default value is 1.

   186  *   timezone   Difference in seconds between coordinated universal

   187  *              time and local time. E.g., -28,800 for PST (GMT-8hrs)

   188  *   tzname(0)  Three-letter time-zone name derived from TZ environment

   189  *              variable. E.g., "PST".

   190  *   tzname(1)  Three-letter DST zone name derived from TZ environment

   191  *              variable.  E.g., "PDT". If DST zone is omitted from TZ,

   192  *              tzname(1) is an empty string.

   193  *

   194  * Notes: For example, to set the TZ environment variable to correspond

   195  * to the current time zone in Germany, you can use one of the

   196  * following statements:

   197  *

   198  *   set TZ=GST1GDT

   199  *   set TZ=GST+1GDT

   200  *

   201  * If the TZ value is not set, t_tzset() attempts to use the time zone

   202  * information specified by the operating system. Under Windows NT

   203  * and Windows 95, this information is specified in the Control Panel's

   204  * Date/Time application.

   205  * @internal

   206  */

   207 U_INTERNAL void     U_EXPORT2 uprv_tzset(void);

   208 

   209 /**

   210  * Difference in seconds between coordinated universal

   211  * time and local time. E.g., -28,800 for PST (GMT-8hrs)

   212  * @return the difference in seconds between coordinated universal time and local time.

   213  * @internal

   214  */

   215 U_INTERNAL int32_t  U_EXPORT2 uprv_timezone(void);

   216 

   217 /**

   218  *   tzname(0)  Three-letter time-zone name derived from TZ environment

   219  *              variable. E.g., "PST".

   220  *   tzname(1)  Three-letter DST zone name derived from TZ environment

   221  *              variable.  E.g., "PDT". If DST zone is omitted from TZ,

   222  *              tzname(1) is an empty string.

   223  * @internal

   224  */

   225 U_INTERNAL const char* U_EXPORT2 uprv_tzname(int n);

   226 

   227 /**

   228  * Get UTC (GMT) time measured in milliseconds since 0:00 on 1/1/1970.

   229  * @return the UTC time measured in milliseconds 

   230  * @internal

   231  */

   232 U_INTERNAL UDate U_EXPORT2 uprv_getUTCtime(void);

   233 

   234 /**

   235  * Determine whether a pathname is absolute or not, as defined by the platform.

   236  * @param path Pathname to test

   237  * @return TRUE if the path is absolute

   238  * @internal (ICU 3.0)

   239  */

   240 U_INTERNAL UBool U_EXPORT2 uprv_pathIsAbsolute(const char *path);

   241 

   242 /**

   243  * Maximum value of a (void*) - use to indicate the limit of an 'infinite' buffer.

   244  * In fact, buffer sizes must not exceed 2GB so that the difference between

   245  * the buffer limit and the buffer start can be expressed in an int32_t.

   246  *

   247  * The definition of U_MAX_PTR must fulfill the following conditions:

   248  * - return the largest possible pointer greater than base

   249  * - return a valid pointer according to the machine architecture (AS/400, 64-bit, etc.)

   250  * - avoid wrapping around at high addresses

   251  * - make sure that the returned pointer is not farther from base than 0x7fffffff

   252  *

   253  * @param base The beginning of a buffer to find the maximum offset from

   254  * @internal

   255  */

   256 #ifndef U_MAX_PTR

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

   258     /* We have 31-bit pointers. */

   259 #    define U_MAX_PTR(base) ((void *)0x7fffffff)

   260 #  elif defined(OS400)

   261 /*

   262  * With the provided macro we should never be out of range of a given segment

   263  * (a traditional/typical segment that is).  Our segments have 5 bytes for the id

   264  * and 3 bytes for the offset.  The key is that the casting takes care of only

   265  * retrieving the offset portion minus x1000.  Hence, the smallest offset seen in

   266  * a program is x001000 and when casted to an int would be 0.  That's why we can

   267  * only add 0xffefff.  Otherwise, we would exceed the segment.

   268  *

   269  * Currently, 16MB is the current addressing limitation on as/400.  This macro

   270  * may eventually be changed to use 2GB addressability for the newer version of

   271  * as/400 machines.

   272  */

   273 #    define U_MAX_PTR(base) ((void *)(((char *)base)-((int32_t)(base))+((int32_t)0xffefff)))

   274 #  else

   275 #    define U_MAX_PTR(base) ((void *)(((char *)(base)+0x7fffffffu) > (char *)(base) ? ((char *)(base)+0x7fffffffu) : (char *)-1))

   276 #  endif

   277 #endif

   278 

   279 #endif