ustrcase_locale.cpp revision c73f511526464f8e56c242df80552e9b0d94ae3d 
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
25U_CFUNC void
26ustrcase_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 */
70static inline void
71setTempCaseMap(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
84U_CAPI int32_t U_EXPORT2
85u_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
98U_CAPI int32_t U_EXPORT2
99u_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