icuSources/common/ustrcase_locale.cpp

   1 /*
   2 *******************************************************************************
   3 *   Copyright (C) 2011, International Business Machines
   4 *   Corporation and others.  All Rights Reserved.
   5 *******************************************************************************
   6 *   file name:  ustrcase_locale.cpp
   7 *   encoding:   US-ASCII
   8 *   tab size:   8 (not used)
   9 *   indentation:4
  10 *
  11 *   created on: 2011may31
  12 *   created by: Markus W. Scherer
  13 *
  14 *   Locale-sensitive case mapping functions (ones that call uloc_getDefault())
  15 *   were moved here to break dependency cycles among parts of the common library.
  16 */
  17
  18 #include "unicode/utypes.h"
  19 #include "unicode/ucasemap.h"
  20 #include "unicode/uloc.h"
  21 #include "unicode/ustring.h"
  22 #include "ucase.h"
  23 #include "ustr_imp.h"
  24
  25 U_CFUNC void
  26 ustrcase_setTempCaseMapLocale(UCaseMap *csm, const char *locale) {
  27     /*
  28      * We could call ucasemap_setLocale(), but here we really only care about
  29      * the initial language subtag, we need not return the real string via
  30      * ucasemap_getLocale(), and we don't care about only getting "x" from
  31      * "x-some-thing" etc.
  32      *
  33      * We ignore locales with a longer-than-3 initial subtag.
  34      *
  35      * We also do not fill in the locCache because it is rarely used,
  36      * and not worth setting unless we reuse it for many case mapping operations.
  37      * (That's why UCaseMap was created.)
  38      */
  39     int i;
  40     char c;
  41
  42     /* the internal functions require locale!=NULL */
  43     if(locale==NULL) {
  44         // Do not call uprv_getDefaultLocaleID() because that does not see
  45         // changes to the default locale via uloc_setDefault().
  46         // It would also be inefficient if used frequently because uprv_getDefaultLocaleID()
  47         // does not cache the locale ID.
  48         //
  49         // Unfortunately, uloc_getDefault() has many dependencies.
  50         // We only care about a small set of language subtags,
  51         // and we do not need the locale ID to be canonicalized.
  52         //
  53         // Best is to not call case mapping functions with a NULL locale ID.
  54         locale=uloc_getDefault();
  55     }
  56     for(i=0; i<4 && (c=locale[i])!=0 && c!='-' && c!='_'; ++i) {
  57         csm->locale[i]=c;
  58     }
  59     if(i<=3) {
  60         csm->locale[i]=0;  /* Up to 3 non-separator characters. */
  61     } else {
  62         csm->locale[0]=0;  /* Longer-than-3 initial subtag: Ignore. */
  63     }
  64 }
  65
  66 /*
  67  * Set parameters on an empty UCaseMap, for UCaseMap-less API functions.
  68  * Do this fast because it is called with every function call.
  69  */
  70 static inline void
  71 setTempCaseMap(UCaseMap *csm, const char *locale) {
  72     if(csm->csp==NULL) {
  73         csm->csp=ucase_getSingleton();
  74     }
  75     if(locale!=NULL && locale[0]==0) {
  76         csm->locale[0]=0;
  77     } else {
  78         ustrcase_setTempCaseMapLocale(csm, locale);
  79     }
  80 }
  81
  82 /* public API functions */
  83
  84 U_CAPI int32_t U_EXPORT2
  85 u_strToLower(UChar *dest, int32_t destCapacity,
  86              const UChar *src, int32_t srcLength,
  87              const char *locale,
  88              UErrorCode *pErrorCode) {
  89     UCaseMap csm=UCASEMAP_INITIALIZER;
  90     setTempCaseMap(&csm, locale);
  91     return ustrcase_map(
  92         &csm,
  93         dest, destCapacity,
  94         src, srcLength,
  95         ustrcase_internalToLower, pErrorCode);
  96 }
  97
  98 U_CAPI int32_t U_EXPORT2
  99 u_strToUpper(UChar *dest, int32_t destCapacity,
 100              const UChar *src, int32_t srcLength,
 101              const char *locale,
 102              UErrorCode *pErrorCode) {
 103     UCaseMap csm=UCASEMAP_INITIALIZER;
 104     setTempCaseMap(&csm, locale);
 105     return ustrcase_map(
 106         &csm,
 107         dest, destCapacity,
 108         src, srcLength,
 109         ustrcase_internalToUpper, pErrorCode);
 110 }