icuSources/common/putilimp.h

   1 /*
   2 ******************************************************************************
   3 *
   4 *   Copyright (C) 1997-2010, 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  * Floating point utility to calculate the logarithm of a double.
 139  * @internal
 140  */
 141 U_INTERNAL double  U_EXPORT2 uprv_log(double d);
 142
 143 /**
 144  * Does common notion of rounding e.g. uprv_floor(x + 0.5);
 145  * @param x the double number
 146  * @return the rounded double
 147  * @internal
 148  */
 149 U_INTERNAL double  U_EXPORT2 uprv_round(double x);
 150
 151 #if 0
 152 /**
 153  * Returns the number of digits after the decimal point in a double number x.
 154  *
 155  * @param x the double number
 156  * @return the number of digits after the decimal point in a double number x.
 157  * @internal
 158  */
 159 /*U_INTERNAL int32_t  U_EXPORT2 uprv_digitsAfterDecimal(double x);*/
 160 #endif
 161
 162 /**
 163  * Time zone utilities
 164  *
 165  * Wrappers for C runtime library functions relating to timezones.
 166  * The t_tzset() function (similar to tzset) uses the current setting
 167  * of the environment variable TZ to assign values to three global
 168  * variables: daylight, timezone, and tzname. These variables have the
 169  * following meanings, and are declared in &lt;time.h&gt;.
 170  *
 171  *   daylight   Nonzero if daylight-saving-time zone (DST) is specified
 172  *              in TZ; otherwise, 0. Default value is 1.
 173  *   timezone   Difference in seconds between coordinated universal
 174  *              time and local time. E.g., -28,800 for PST (GMT-8hrs)
 175  *   tzname(0)  Three-letter time-zone name derived from TZ environment
 176  *              variable. E.g., "PST".
 177  *   tzname(1)  Three-letter DST zone name derived from TZ environment
 178  *              variable.  E.g., "PDT". If DST zone is omitted from TZ,
 179  *              tzname(1) is an empty string.
 180  *
 181  * Notes: For example, to set the TZ environment variable to correspond
 182  * to the current time zone in Germany, you can use one of the
 183  * following statements:
 184  *
 185  *   set TZ=GST1GDT
 186  *   set TZ=GST+1GDT
 187  *
 188  * If the TZ value is not set, t_tzset() attempts to use the time zone
 189  * information specified by the operating system. Under Windows NT
 190  * and Windows 95, this information is specified in the Control Panel's
 191  * Date/Time application.
 192  * @internal
 193  */
 194 U_INTERNAL void     U_EXPORT2 uprv_tzset(void);
 195
 196 /**
 197  * Difference in seconds between coordinated universal
 198  * time and local time. E.g., -28,800 for PST (GMT-8hrs)
 199  * @return the difference in seconds between coordinated universal time and local time.
 200  * @internal
 201  */
 202 U_INTERNAL int32_t  U_EXPORT2 uprv_timezone(void);
 203
 204 /**
 205  *   tzname(0)  Three-letter time-zone name derived from TZ environment
 206  *              variable. E.g., "PST".
 207  *   tzname(1)  Three-letter DST zone name derived from TZ environment
 208  *              variable.  E.g., "PDT". If DST zone is omitted from TZ,
 209  *              tzname(1) is an empty string.
 210  * @internal
 211  */
 212 U_INTERNAL const char* U_EXPORT2 uprv_tzname(int n);
 213
 214 /**
 215  * Get UTC (GMT) time measured in milliseconds since 0:00 on 1/1/1970.
 216  * This function is affected by 'faketime' and should be the bottleneck for all user-visible ICU time functions.
 217  * @return the UTC time measured in milliseconds
 218  * @internal
 219  */
 220 U_INTERNAL UDate U_EXPORT2 uprv_getUTCtime(void);
 221
 222 /**
 223  * Get UTC (GMT) time measured in milliseconds since 0:00 on 1/1/1970.
 224  * This function is not affected by 'faketime', so it should only be used by low level test functions- not by anything that
 225  * exposes time to the end user.
 226  * @return the UTC time measured in milliseconds
 227  * @internal
 228  */
 229 U_INTERNAL UDate U_EXPORT2 uprv_getRawUTCtime(void);
 230
 231 /**
 232  * Determine whether a pathname is absolute or not, as defined by the platform.
 233  * @param path Pathname to test
 234  * @return TRUE if the path is absolute
 235  * @internal (ICU 3.0)
 236  */
 237 U_INTERNAL UBool U_EXPORT2 uprv_pathIsAbsolute(const char *path);
 238
 239 /**
 240  * Use U_MAX_PTR instead of this function.
 241  * @param void pointer to test
 242  * @return the largest possible pointer greater than the base
 243  * @internal (ICU 3.8)
 244  */
 245 U_INTERNAL void * U_EXPORT2 uprv_maximumPtr(void *base);
 246
 247 /**
 248  * Maximum value of a (void*) - use to indicate the limit of an 'infinite' buffer.
 249  * In fact, buffer sizes must not exceed 2GB so that the difference between
 250  * the buffer limit and the buffer start can be expressed in an int32_t.
 251  *
 252  * The definition of U_MAX_PTR must fulfill the following conditions:
 253  * - return the largest possible pointer greater than base
 254  * - return a valid pointer according to the machine architecture (AS/400, 64-bit, etc.)
 255  * - avoid wrapping around at high addresses
 256  * - make sure that the returned pointer is not farther from base than 0x7fffffff
 257  *
 258  * @param base The beginning of a buffer to find the maximum offset from
 259  * @internal
 260  */
 261 #ifndef U_MAX_PTR
 262 #  if defined(OS390) && !defined(_LP64)
 263     /* We have 31-bit pointers. */
 264 #    define U_MAX_PTR(base) ((void *)0x7fffffff)
 265 #  elif defined(OS400)
 266 #    define U_MAX_PTR(base) uprv_maximumPtr((void *)base)
 267 #  elif defined(__GNUC__) && __GNUC__ >= 4
 268 /*
 269  * Due to a compiler optimization bug, gcc 4 causes test failures when doing
 270  * this math arithmetic on pointers on some platforms. It seems like the
 271  * pointers are considered signed instead of unsigned. The uintptr_t type
 272  * isn't available on all platforms (i.e MSVC 6) and pointers aren't always
 273  * a scalar value (i.e. i5/OS see uprv_maximumPtr function).
 274  */
 275 #    define U_MAX_PTR(base) \
 276     ((void *)(((uintptr_t)(base)+0x7fffffffu) > (uintptr_t)(base) \
 277         ? ((uintptr_t)(base)+0x7fffffffu) \
 278         : (uintptr_t)-1))
 279 #  else
 280 #    define U_MAX_PTR(base) \
 281     ((char *)(((char *)(base)+0x7fffffffu) > (char *)(base) \
 282         ? ((char *)(base)+0x7fffffffu) \
 283         : (char *)-1))
 284 #  endif
 285 #endif
 286
 287 #if U_ENABLE_DYLOAD
 288 /*  Dynamic Library Functions */
 289
 290 /**
 291  * Load a library
 292  * @internal (ICU 4.4)
 293  */
 294 U_INTERNAL void * U_EXPORT2 uprv_dl_open(const char *libName, UErrorCode *status);
 295
 296 /**
 297  * Close a library
 298  * @internal (ICU 4.4)
 299  */
 300 U_INTERNAL void U_EXPORT2 uprv_dl_close( void *lib, UErrorCode *status);
 301
 302 /**
 303  * Extract a symbol from a library
 304  * @internal (ICU 4.4)
 305  */
 306 U_INTERNAL void * U_EXPORT2 uprv_dl_sym( void *lib, const char *symbolName, UErrorCode *status);
 307
 308 #endif
 309
 310 #endif