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      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 }
    111