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1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 **********************************************************************
5 *   Copyright (C) 1999-2014, International Business Machines
6 *   Corporation and others.  All Rights Reserved.
7 **********************************************************************
8  *  ucnv.h:
9  *  External APIs for the ICU's codeset conversion library
10  *  Bertrand A. Damiba
11  *
12  * Modification History:
13  *
14  *   Date        Name        Description
15  *   04/04/99    helena      Fixed internal header inclusion.
16  *   05/11/00    helena      Added setFallback and usesFallback APIs.
17  *   06/29/2000  helena      Major rewrite of the callback APIs.
18  *   12/07/2000  srl         Update of documentation
19  */
20 
21 /**
22  * \file
23  * \brief C API: Character conversion
24  *
25  * <h2>Character Conversion C API</h2>
26  *
27  * <p>This API is used to convert codepage or character encoded data to and
28  * from UTF-16. You can open a converter with {@link ucnv_open() }. With that
29  * converter, you can get its properties, set options, convert your data and
30  * close the converter.</p>
31  *
32  * <p>Since many software programs recognize different converter names for
33  * different types of converters, there are other functions in this API to
34  * iterate over the converter aliases. The functions {@link ucnv_getAvailableName() },
35  * {@link ucnv_getAlias() } and {@link ucnv_getStandardName() } are some of the
36  * more frequently used alias functions to get this information.</p>
37  *
38  * <p>When a converter encounters an illegal, irregular, invalid or unmappable character
39  * its default behavior is to use a substitution character to replace the
40  * bad byte sequence. This behavior can be changed by using {@link ucnv_setFromUCallBack() }
41  * or {@link ucnv_setToUCallBack() } on the converter. The header ucnv_err.h defines
42  * many other callback actions that can be used instead of a character substitution.</p>
43  *
44  * <p>More information about this API can be found in our
45  * <a href="https://unicode-org.github.io/icu/userguide/conversion/">User Guide</a>.</p>
46  */
47 
48 #ifndef UCNV_H
49 #define UCNV_H
50 
51 #include "unicode/ucnv_err.h"
52 #include "unicode/uenum.h"
53 
54 #if U_SHOW_CPLUSPLUS_API
55 #include "unicode/localpointer.h"
56 #endif   // U_SHOW_CPLUSPLUS_API
57 
58 #if !defined(USET_DEFINED) && !defined(U_IN_DOXYGEN)
59 
60 #define USET_DEFINED
61 
62 /**
63  * USet is the C API type corresponding to C++ class UnicodeSet.
64  * It is forward-declared here to avoid including unicode/uset.h file if related
65  * conversion APIs are not used.
66  *
67  * @see ucnv_getUnicodeSet
68  * @stable ICU 2.4
69  */
70 typedef struct USet USet;
71 
72 #endif
73 
74 #if !UCONFIG_NO_CONVERSION
75 
76 U_CDECL_BEGIN
77 
78 /** Maximum length of a converter name including the terminating NULL @stable ICU 2.0 */
79 #define UCNV_MAX_CONVERTER_NAME_LENGTH 60
80 /** Maximum length of a converter name including path and terminating NULL @stable ICU 2.0 */
81 #define UCNV_MAX_FULL_FILE_NAME_LENGTH (600+UCNV_MAX_CONVERTER_NAME_LENGTH)
82 
83 /** Shift in for EBDCDIC_STATEFUL and iso2022 states @stable ICU 2.0 */
84 #define  UCNV_SI 0x0F
85 /** Shift out for EBDCDIC_STATEFUL and iso2022 states @stable ICU 2.0 */
86 #define  UCNV_SO 0x0E
87 
88 /**
89  * Enum for specifying basic types of converters
90  * @see ucnv_getType
91  * @stable ICU 2.0
92  */
93 typedef enum {
94     /** @stable ICU 2.0 */
95     UCNV_UNSUPPORTED_CONVERTER = -1,
96     /** @stable ICU 2.0 */
97     UCNV_SBCS = 0,
98     /** @stable ICU 2.0 */
99     UCNV_DBCS = 1,
100     /** @stable ICU 2.0 */
101     UCNV_MBCS = 2,
102     /** @stable ICU 2.0 */
103     UCNV_LATIN_1 = 3,
104     /** @stable ICU 2.0 */
105     UCNV_UTF8 = 4,
106     /** @stable ICU 2.0 */
107     UCNV_UTF16_BigEndian = 5,
108     /** @stable ICU 2.0 */
109     UCNV_UTF16_LittleEndian = 6,
110     /** @stable ICU 2.0 */
111     UCNV_UTF32_BigEndian = 7,
112     /** @stable ICU 2.0 */
113     UCNV_UTF32_LittleEndian = 8,
114     /** @stable ICU 2.0 */
115     UCNV_EBCDIC_STATEFUL = 9,
116     /** @stable ICU 2.0 */
117     UCNV_ISO_2022 = 10,
118 
119     /** @stable ICU 2.0 */
120     UCNV_LMBCS_1 = 11,
121     /** @stable ICU 2.0 */
122     UCNV_LMBCS_2,
123     /** @stable ICU 2.0 */
124     UCNV_LMBCS_3,
125     /** @stable ICU 2.0 */
126     UCNV_LMBCS_4,
127     /** @stable ICU 2.0 */
128     UCNV_LMBCS_5,
129     /** @stable ICU 2.0 */
130     UCNV_LMBCS_6,
131     /** @stable ICU 2.0 */
132     UCNV_LMBCS_8,
133     /** @stable ICU 2.0 */
134     UCNV_LMBCS_11,
135     /** @stable ICU 2.0 */
136     UCNV_LMBCS_16,
137     /** @stable ICU 2.0 */
138     UCNV_LMBCS_17,
139     /** @stable ICU 2.0 */
140     UCNV_LMBCS_18,
141     /** @stable ICU 2.0 */
142     UCNV_LMBCS_19,
143     /** @stable ICU 2.0 */
144     UCNV_LMBCS_LAST = UCNV_LMBCS_19,
145     /** @stable ICU 2.0 */
146     UCNV_HZ,
147     /** @stable ICU 2.0 */
148     UCNV_SCSU,
149     /** @stable ICU 2.0 */
150     UCNV_ISCII,
151     /** @stable ICU 2.0 */
152     UCNV_US_ASCII,
153     /** @stable ICU 2.0 */
154     UCNV_UTF7,
155     /** @stable ICU 2.2 */
156     UCNV_BOCU1,
157     /** @stable ICU 2.2 */
158     UCNV_UTF16,
159     /** @stable ICU 2.2 */
160     UCNV_UTF32,
161     /** @stable ICU 2.2 */
162     UCNV_CESU8,
163     /** @stable ICU 2.4 */
164     UCNV_IMAP_MAILBOX,
165     /** @stable ICU 4.8 */
166     UCNV_COMPOUND_TEXT,
167 
168     /* Number of converter types for which we have conversion routines. */
169     UCNV_NUMBER_OF_SUPPORTED_CONVERTER_TYPES
170 } UConverterType;
171 
172 /**
173  * Enum for specifying which platform a converter ID refers to.
174  * The use of platform/CCSID is not recommended. See ucnv_openCCSID().
175  *
176  * @see ucnv_getPlatform
177  * @see ucnv_openCCSID
178  * @see ucnv_getCCSID
179  * @stable ICU 2.0
180  */
181 typedef enum {
182     UCNV_UNKNOWN = -1,
183     UCNV_IBM = 0
184 } UConverterPlatform;
185 
186 /**
187  * Function pointer for error callback in the codepage to unicode direction.
188  * Called when an error has occurred in conversion to unicode, or on open/close of the callback (see reason).
189  * @param context Pointer to the callback's private data
190  * @param args Information about the conversion in progress
191  * @param codeUnits Points to 'length' bytes of the concerned codepage sequence
192  * @param length Size (in bytes) of the concerned codepage sequence
193  * @param reason Defines the reason the callback was invoked
194  * @param pErrorCode    ICU error code in/out parameter.
195  *                      For converter callback functions, set to a conversion error
196  *                      before the call, and the callback may reset it to U_ZERO_ERROR.
197  * @see ucnv_setToUCallBack
198  * @see UConverterToUnicodeArgs
199  * @stable ICU 2.0
200  */
201 typedef void (U_EXPORT2 *UConverterToUCallback) (
202                   const void* context,
203                   UConverterToUnicodeArgs *args,
204                   const char *codeUnits,
205                   int32_t length,
206                   UConverterCallbackReason reason,
207                   UErrorCode *pErrorCode);
208 
209 /**
210  * Function pointer for error callback in the unicode to codepage direction.
211  * Called when an error has occurred in conversion from unicode, or on open/close of the callback (see reason).
212  * @param context Pointer to the callback's private data
213  * @param args Information about the conversion in progress
214  * @param codeUnits Points to 'length' UChars of the concerned Unicode sequence
215  * @param length Size (in bytes) of the concerned codepage sequence
216  * @param codePoint Single UChar32 (UTF-32) containing the concerend Unicode codepoint.
217  * @param reason Defines the reason the callback was invoked
218  * @param pErrorCode    ICU error code in/out parameter.
219  *                      For converter callback functions, set to a conversion error
220  *                      before the call, and the callback may reset it to U_ZERO_ERROR.
221  * @see ucnv_setFromUCallBack
222  * @stable ICU 2.0
223  */
224 typedef void (U_EXPORT2 *UConverterFromUCallback) (
225                     const void* context,
226                     UConverterFromUnicodeArgs *args,
227                     const UChar* codeUnits,
228                     int32_t length,
229                     UChar32 codePoint,
230                     UConverterCallbackReason reason,
231                     UErrorCode *pErrorCode);
232 
233 U_CDECL_END
234 
235 /**
236  * Character that separates converter names from options and options from each other.
237  * @see ucnv_open
238  * @stable ICU 2.0
239  */
240 #define UCNV_OPTION_SEP_CHAR ','
241 
242 /**
243  * String version of UCNV_OPTION_SEP_CHAR.
244  * @see ucnv_open
245  * @stable ICU 2.0
246  */
247 #define UCNV_OPTION_SEP_STRING ","
248 
249 /**
250  * Character that separates a converter option from its value.
251  * @see ucnv_open
252  * @stable ICU 2.0
253  */
254 #define UCNV_VALUE_SEP_CHAR '='
255 
256 /**
257  * String version of UCNV_VALUE_SEP_CHAR.
258  * @see ucnv_open
259  * @stable ICU 2.0
260  */
261 #define UCNV_VALUE_SEP_STRING "="
262 
263 /**
264  * Converter option for specifying a locale.
265  * For example, ucnv_open("SCSU,locale=ja", &errorCode);
266  * See convrtrs.txt.
267  *
268  * @see ucnv_open
269  * @stable ICU 2.0
270  */
271 #define UCNV_LOCALE_OPTION_STRING ",locale="
272 
273 /**
274  * Converter option for specifying a version selector (0..9) for some converters.
275  * For example,
276  * \code
277  *   ucnv_open("UTF-7,version=1", &errorCode);
278  * \endcode
279  * See convrtrs.txt.
280  *
281  * @see ucnv_open
282  * @stable ICU 2.4
283  */
284 #define UCNV_VERSION_OPTION_STRING ",version="
285 
286 /**
287  * Converter option for EBCDIC SBCS or mixed-SBCS/DBCS (stateful) codepages.
288  * Swaps Unicode mappings for EBCDIC LF and NL codes, as used on
289  * S/390 (z/OS) Unix System Services (Open Edition).
290  * For example, ucnv_open("ibm-1047,swaplfnl", &errorCode);
291  * See convrtrs.txt.
292  *
293  * @see ucnv_open
294  * @stable ICU 2.4
295  */
296 #define UCNV_SWAP_LFNL_OPTION_STRING ",swaplfnl"
297 
298 /**
299  * Do a fuzzy compare of two converter/alias names.
300  * The comparison is case-insensitive, ignores leading zeroes if they are not
301  * followed by further digits, and ignores all but letters and digits.
302  * Thus the strings "UTF-8", "utf_8", "u*T@f08" and "Utf 8" are exactly equivalent.
303  * See section 1.4, Charset Alias Matching in Unicode Technical Standard #22
304  * at http://www.unicode.org/reports/tr22/
305  *
306  * @param name1 a converter name or alias, zero-terminated
307  * @param name2 a converter name or alias, zero-terminated
308  * @return 0 if the names match, or a negative value if the name1
309  * lexically precedes name2, or a positive value if the name1
310  * lexically follows name2.
311  * @stable ICU 2.0
312  */
313 U_CAPI int U_EXPORT2
314 ucnv_compareNames(const char *name1, const char *name2);
315 
316 
317 /**
318  * Creates a UConverter object with the name of a coded character set specified as a C string.
319  * The actual name will be resolved with the alias file
320  * using a case-insensitive string comparison that ignores
321  * leading zeroes and all non-alphanumeric characters.
322  * E.g., the names "UTF8", "utf-8", "u*T@f08" and "Utf 8" are all equivalent.
323  * (See also ucnv_compareNames().)
324  * If <code>NULL</code> is passed for the converter name, it will create one with the
325  * getDefaultName return value.
326  *
327  * <p>A converter name for ICU 1.5 and above may contain options
328  * like a locale specification to control the specific behavior of
329  * the newly instantiated converter.
330  * The meaning of the options depends on the particular converter.
331  * If an option is not defined for or recognized by a given converter, then it is ignored.</p>
332  *
333  * <p>Options are appended to the converter name string, with a
334  * <code>UCNV_OPTION_SEP_CHAR</code> between the name and the first option and
335  * also between adjacent options.</p>
336  *
337  * <p>If the alias is ambiguous, then the preferred converter is used
338  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.</p>
339  *
340  * <p>The conversion behavior and names can vary between platforms. ICU may
341  * convert some characters differently from other platforms. Details on this topic
342  * are in the <a href="https://unicode-org.github.io/icu/userguide/conversion/">User
343  * Guide</a>. Aliases starting with a "cp" prefix have no specific meaning
344  * other than its an alias starting with the letters "cp". Please do not
345  * associate any meaning to these aliases.</p>
346  *
347  * \snippet samples/ucnv/convsamp.cpp ucnv_open
348  *
349  * @param converterName Name of the coded character set table.
350  *          This may have options appended to the string.
351  *          IANA alias character set names, IBM CCSIDs starting with "ibm-",
352  *          Windows codepage numbers starting with "windows-" are frequently
353  *          used for this parameter. See ucnv_getAvailableName and
354  *          ucnv_getAlias for a complete list that is available.
355  *          If this parameter is NULL, the default converter will be used.
356  * @param err outgoing error status <TT>U_MEMORY_ALLOCATION_ERROR, U_FILE_ACCESS_ERROR</TT>
357  * @return the created Unicode converter object, or <TT>NULL</TT> if an error occurred
358  * @see ucnv_openU
359  * @see ucnv_openCCSID
360  * @see ucnv_getAvailableName
361  * @see ucnv_getAlias
362  * @see ucnv_getDefaultName
363  * @see ucnv_close
364  * @see ucnv_compareNames
365  * @stable ICU 2.0
366  */
367 U_CAPI UConverter* U_EXPORT2
368 ucnv_open(const char *converterName, UErrorCode *err);
369 
370 
371 /**
372  * Creates a Unicode converter with the names specified as unicode string.
373  * The name should be limited to the ASCII-7 alphanumerics range.
374  * The actual name will be resolved with the alias file
375  * using a case-insensitive string comparison that ignores
376  * leading zeroes and all non-alphanumeric characters.
377  * E.g., the names "UTF8", "utf-8", "u*T@f08" and "Utf 8" are all equivalent.
378  * (See also ucnv_compareNames().)
379  * If <TT>NULL</TT> is passed for the converter name, it will create
380  * one with the ucnv_getDefaultName() return value.
381  * If the alias is ambiguous, then the preferred converter is used
382  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
383  *
384  * <p>See ucnv_open for the complete details</p>
385  * @param name Name of the UConverter table in a zero terminated
386  *        Unicode string
387  * @param err outgoing error status <TT>U_MEMORY_ALLOCATION_ERROR,
388  *        U_FILE_ACCESS_ERROR</TT>
389  * @return the created Unicode converter object, or <TT>NULL</TT> if an
390  *        error occurred
391  * @see ucnv_open
392  * @see ucnv_openCCSID
393  * @see ucnv_close
394  * @see ucnv_compareNames
395  * @stable ICU 2.0
396  */
397 U_CAPI UConverter* U_EXPORT2
398 ucnv_openU(const UChar *name,
399            UErrorCode *err);
400 
401 /**
402  * Creates a UConverter object from a CCSID number and platform pair.
403  * Note that the usefulness of this function is limited to platforms with numeric
404  * encoding IDs. Only IBM and Microsoft platforms use numeric (16-bit) identifiers for
405  * encodings.
406  *
407  * In addition, IBM CCSIDs and Unicode conversion tables are not 1:1 related.
408  * For many IBM CCSIDs there are multiple (up to six) Unicode conversion tables, and
409  * for some Unicode conversion tables there are multiple CCSIDs.
410  * Some "alternate" Unicode conversion tables are provided by the
411  * IBM CDRA conversion table registry.
412  * The most prominent example of a systematic modification of conversion tables that is
413  * not provided in the form of conversion table files in the repository is
414  * that S/390 Unix System Services swaps the codes for Line Feed and New Line in all
415  * EBCDIC codepages, which requires such a swap in the Unicode conversion tables as well.
416  *
417  * Only IBM default conversion tables are accessible with ucnv_openCCSID().
418  * ucnv_getCCSID() will return the same CCSID for all conversion tables that are associated
419  * with that CCSID.
420  *
421  * Currently, the only "platform" supported in the ICU converter API is UCNV_IBM.
422  *
423  * In summary, the use of CCSIDs and the associated API functions is not recommended.
424  *
425  * In order to open a converter with the default IBM CDRA Unicode conversion table,
426  * you can use this function or use the prefix "ibm-":
427  * \code
428  *     char name[20];
429  *     sprintf(name, "ibm-%hu", ccsid);
430  *     cnv=ucnv_open(name, &errorCode);
431  * \endcode
432  *
433  * In order to open a converter with the IBM S/390 Unix System Services variant
434  * of a Unicode/EBCDIC conversion table,
435  * you can use the prefix "ibm-" together with the option string UCNV_SWAP_LFNL_OPTION_STRING:
436  * \code
437  *     char name[20];
438  *     sprintf(name, "ibm-%hu" UCNV_SWAP_LFNL_OPTION_STRING, ccsid);
439  *     cnv=ucnv_open(name, &errorCode);
440  * \endcode
441  *
442  * In order to open a converter from a Microsoft codepage number, use the prefix "cp":
443  * \code
444  *     char name[20];
445  *     sprintf(name, "cp%hu", codepageID);
446  *     cnv=ucnv_open(name, &errorCode);
447  * \endcode
448  *
449  * If the alias is ambiguous, then the preferred converter is used
450  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
451  *
452  * @param codepage codepage number to create
453  * @param platform the platform in which the codepage number exists
454  * @param err error status <TT>U_MEMORY_ALLOCATION_ERROR, U_FILE_ACCESS_ERROR</TT>
455  * @return the created Unicode converter object, or <TT>NULL</TT> if an error
456  *   occurred.
457  * @see ucnv_open
458  * @see ucnv_openU
459  * @see ucnv_close
460  * @see ucnv_getCCSID
461  * @see ucnv_getPlatform
462  * @see UConverterPlatform
463  * @stable ICU 2.0
464  */
465 U_CAPI UConverter* U_EXPORT2
466 ucnv_openCCSID(int32_t codepage,
467                UConverterPlatform platform,
468                UErrorCode * err);
469 
470 /**
471  * <p>Creates a UConverter object specified from a packageName and a converterName.</p>
472  *
473  * <p>The packageName and converterName must point to an ICU udata object, as defined by
474  *   <code> udata_open( packageName, "cnv", converterName, err) </code> or equivalent.
475  * Typically, packageName will refer to a (.dat) file, or to a package registered with
476  * udata_setAppData(). Using a full file or directory pathname for packageName is deprecated.</p>
477  *
478  * <p>The name will NOT be looked up in the alias mechanism, nor will the converter be
479  * stored in the converter cache or the alias table. The only way to open further converters
480  * is call this function multiple times, or use the ucnv_safeClone() function to clone a
481  * 'primary' converter.</p>
482  *
483  * <p>A future version of ICU may add alias table lookups and/or caching
484  * to this function.</p>
485  *
486  * <p>Example Use:
487  *      <code>cnv = ucnv_openPackage("myapp", "myconverter", &err);</code>
488  * </p>
489  *
490  * @param packageName name of the package (equivalent to 'path' in udata_open() call)
491  * @param converterName name of the data item to be used, without suffix.
492  * @param err outgoing error status <TT>U_MEMORY_ALLOCATION_ERROR, U_FILE_ACCESS_ERROR</TT>
493  * @return the created Unicode converter object, or <TT>NULL</TT> if an error occurred
494  * @see udata_open
495  * @see ucnv_open
496  * @see ucnv_safeClone
497  * @see ucnv_close
498  * @stable ICU 2.2
499  */
500 U_CAPI UConverter* U_EXPORT2
501 ucnv_openPackage(const char *packageName, const char *converterName, UErrorCode *err);
502 
503 /**
504  * Thread safe converter cloning operation.
505  * For most efficient operation, pass in a stackBuffer (and a *pBufferSize)
506  * with at least U_CNV_SAFECLONE_BUFFERSIZE bytes of space.
507  * If the buffer size is sufficient, then the clone will use the stack buffer;
508  * otherwise, it will be allocated, and *pBufferSize will indicate
509  * the actual size. (This should not occur with U_CNV_SAFECLONE_BUFFERSIZE.)
510  *
511  * You must ucnv_close() the clone in any case.
512  *
513  * If *pBufferSize==0, (regardless of whether stackBuffer==NULL or not)
514  * then *pBufferSize will be changed to a sufficient size
515  * for cloning this converter,
516  * without actually cloning the converter ("pure pre-flighting").
517  *
518  * If *pBufferSize is greater than zero but not large enough for a stack-based
519  * clone, then the converter is cloned using newly allocated memory
520  * and *pBufferSize is changed to the necessary size.
521  *
522  * If the converter clone fits into the stack buffer but the stack buffer is not
523  * sufficiently aligned for the clone, then the clone will use an
524  * adjusted pointer and use an accordingly smaller buffer size.
525  *
526  * @param cnv converter to be cloned
527  * @param stackBuffer <em>Deprecated functionality as of ICU 52, use NULL.</em><br>
528  *  user allocated space for the new clone. If NULL new memory will be allocated.
529  *  If buffer is not large enough, new memory will be allocated.
530  *  Clients can use the U_CNV_SAFECLONE_BUFFERSIZE. This will probably be enough to avoid memory allocations.
531  * @param pBufferSize <em>Deprecated functionality as of ICU 52, use NULL or 1.</em><br>
532  *  pointer to size of allocated space.
533  * @param status to indicate whether the operation went on smoothly or there were errors
534  *  An informational status value, U_SAFECLONE_ALLOCATED_WARNING,
535  *  is used if any allocations were necessary.
536  *  However, it is better to check if *pBufferSize grew for checking for
537  *  allocations because warning codes can be overridden by subsequent
538  *  function calls.
539  * @return pointer to the new clone
540  * @stable ICU 2.0
541  */
542 U_CAPI UConverter * U_EXPORT2
543 ucnv_safeClone(const UConverter *cnv,
544                void             *stackBuffer,
545                int32_t          *pBufferSize,
546                UErrorCode       *status);
547 
548 #ifndef U_HIDE_DEPRECATED_API
549 
550 /**
551  * \def U_CNV_SAFECLONE_BUFFERSIZE
552  * Definition of a buffer size that is designed to be large enough for
553  * converters to be cloned with ucnv_safeClone().
554  * @deprecated ICU 52. Do not rely on ucnv_safeClone() cloning into any provided buffer.
555  */
556 #define U_CNV_SAFECLONE_BUFFERSIZE  1024
557 
558 #endif /* U_HIDE_DEPRECATED_API */
559 
560 /**
561  * Deletes the unicode converter and releases resources associated
562  * with just this instance.
563  * Does not free up shared converter tables.
564  *
565  * @param converter the converter object to be deleted
566  * @see ucnv_open
567  * @see ucnv_openU
568  * @see ucnv_openCCSID
569  * @stable ICU 2.0
570  */
571 U_CAPI void  U_EXPORT2
572 ucnv_close(UConverter * converter);
573 
574 #if U_SHOW_CPLUSPLUS_API
575 
576 U_NAMESPACE_BEGIN
577 
578 /**
579  * \class LocalUConverterPointer
580  * "Smart pointer" class, closes a UConverter via ucnv_close().
581  * For most methods see the LocalPointerBase base class.
582  *
583  * @see LocalPointerBase
584  * @see LocalPointer
585  * @stable ICU 4.4
586  */
587 U_DEFINE_LOCAL_OPEN_POINTER(LocalUConverterPointer, UConverter, ucnv_close);
588 
589 U_NAMESPACE_END
590 
591 #endif
592 
593 /**
594  * Fills in the output parameter, subChars, with the substitution characters
595  * as multiple bytes.
596  * If ucnv_setSubstString() set a Unicode string because the converter is
597  * stateful, then subChars will be an empty string.
598  *
599  * @param converter the Unicode converter
600  * @param subChars the substitution characters
601  * @param len on input the capacity of subChars, on output the number
602  * of bytes copied to it
603  * @param  err the outgoing error status code.
604  * If the substitution character array is too small, an
605  * <TT>U_INDEX_OUTOFBOUNDS_ERROR</TT> will be returned.
606  * @see ucnv_setSubstString
607  * @see ucnv_setSubstChars
608  * @stable ICU 2.0
609  */
610 U_CAPI void U_EXPORT2
611 ucnv_getSubstChars(const UConverter *converter,
612                    char *subChars,
613                    int8_t *len,
614                    UErrorCode *err);
615 
616 /**
617  * Sets the substitution chars when converting from unicode to a codepage. The
618  * substitution is specified as a string of 1-4 bytes, and may contain
619  * <TT>NULL</TT> bytes.
620  * The subChars must represent a single character. The caller needs to know the
621  * byte sequence of a valid character in the converter's charset.
622  * For some converters, for example some ISO 2022 variants, only single-byte
623  * substitution characters may be supported.
624  * The newer ucnv_setSubstString() function relaxes these limitations.
625  *
626  * @param converter the Unicode converter
627  * @param subChars the substitution character byte sequence we want set
628  * @param len the number of bytes in subChars
629  * @param err the error status code.  <TT>U_INDEX_OUTOFBOUNDS_ERROR </TT> if
630  * len is bigger than the maximum number of bytes allowed in subchars
631  * @see ucnv_setSubstString
632  * @see ucnv_getSubstChars
633  * @stable ICU 2.0
634  */
635 U_CAPI void U_EXPORT2
636 ucnv_setSubstChars(UConverter *converter,
637                    const char *subChars,
638                    int8_t len,
639                    UErrorCode *err);
640 
641 /**
642  * Set a substitution string for converting from Unicode to a charset.
643  * The caller need not know the charset byte sequence for each charset.
644  *
645  * Unlike ucnv_setSubstChars() which is designed to set a charset byte sequence
646  * for a single character, this function takes a Unicode string with
647  * zero, one or more characters, and immediately verifies that the string can be
648  * converted to the charset.
649  * If not, or if the result is too long (more than 32 bytes as of ICU 3.6),
650  * then the function returns with an error accordingly.
651  *
652  * Also unlike ucnv_setSubstChars(), this function works for stateful charsets
653  * by converting on the fly at the point of substitution rather than setting
654  * a fixed byte sequence.
655  *
656  * @param cnv The UConverter object.
657  * @param s The Unicode string.
658  * @param length The number of UChars in s, or -1 for a NUL-terminated string.
659  * @param err Pointer to a standard ICU error code. Its input value must
660  *            pass the U_SUCCESS() test, or else the function returns
661  *            immediately. Check for U_FAILURE() on output or use with
662  *            function chaining. (See User Guide for details.)
663  *
664  * @see ucnv_setSubstChars
665  * @see ucnv_getSubstChars
666  * @stable ICU 3.6
667  */
668 U_CAPI void U_EXPORT2
669 ucnv_setSubstString(UConverter *cnv,
670                     const UChar *s,
671                     int32_t length,
672                     UErrorCode *err);
673 
674 /**
675  * Fills in the output parameter, errBytes, with the error characters from the
676  * last failing conversion.
677  *
678  * @param converter the Unicode converter
679  * @param errBytes the codepage bytes which were in error
680  * @param len on input the capacity of errBytes, on output the number of
681  *  bytes which were copied to it
682  * @param err the error status code.
683  * If the substitution character array is too small, an
684  * <TT>U_INDEX_OUTOFBOUNDS_ERROR</TT> will be returned.
685  * @stable ICU 2.0
686  */
687 U_CAPI void U_EXPORT2
688 ucnv_getInvalidChars(const UConverter *converter,
689                      char *errBytes,
690                      int8_t *len,
691                      UErrorCode *err);
692 
693 /**
694  * Fills in the output parameter, errChars, with the error characters from the
695  * last failing conversion.
696  *
697  * @param converter the Unicode converter
698  * @param errUChars the UChars which were in error
699  * @param len on input the capacity of errUChars, on output the number of
700  *  UChars which were copied to it
701  * @param err the error status code.
702  * If the substitution character array is too small, an
703  * <TT>U_INDEX_OUTOFBOUNDS_ERROR</TT> will be returned.
704  * @stable ICU 2.0
705  */
706 U_CAPI void U_EXPORT2
707 ucnv_getInvalidUChars(const UConverter *converter,
708                       UChar *errUChars,
709                       int8_t *len,
710                       UErrorCode *err);
711 
712 /**
713  * Resets the state of a converter to the default state. This is used
714  * in the case of an error, to restart a conversion from a known default state.
715  * It will also empty the internal output buffers.
716  * @param converter the Unicode converter
717  * @stable ICU 2.0
718  */
719 U_CAPI void U_EXPORT2
720 ucnv_reset(UConverter *converter);
721 
722 /**
723  * Resets the to-Unicode part of a converter state to the default state.
724  * This is used in the case of an error to restart a conversion to
725  * Unicode to a known default state. It will also empty the internal
726  * output buffers used for the conversion to Unicode codepoints.
727  * @param converter the Unicode converter
728  * @stable ICU 2.0
729  */
730 U_CAPI void U_EXPORT2
731 ucnv_resetToUnicode(UConverter *converter);
732 
733 /**
734  * Resets the from-Unicode part of a converter state to the default state.
735  * This is used in the case of an error to restart a conversion from
736  * Unicode to a known default state. It will also empty the internal output
737  * buffers used for the conversion from Unicode codepoints.
738  * @param converter the Unicode converter
739  * @stable ICU 2.0
740  */
741 U_CAPI void U_EXPORT2
742 ucnv_resetFromUnicode(UConverter *converter);
743 
744 /**
745  * Returns the maximum number of bytes that are output per UChar in conversion
746  * from Unicode using this converter.
747  * The returned number can be used with UCNV_GET_MAX_BYTES_FOR_STRING
748  * to calculate the size of a target buffer for conversion from Unicode.
749  *
750  * Note: Before ICU 2.8, this function did not return reliable numbers for
751  * some stateful converters (EBCDIC_STATEFUL, ISO-2022) and LMBCS.
752  *
753  * This number may not be the same as the maximum number of bytes per
754  * "conversion unit". In other words, it may not be the intuitively expected
755  * number of bytes per character that would be published for a charset,
756  * and may not fulfill any other purpose than the allocation of an output
757  * buffer of guaranteed sufficient size for a given input length and converter.
758  *
759  * Examples for special cases that are taken into account:
760  * - Supplementary code points may convert to more bytes than BMP code points.
761  *   This function returns bytes per UChar (UTF-16 code unit), not per
762  *   Unicode code point, for efficient buffer allocation.
763  * - State-shifting output (SI/SO, escapes, etc.) from stateful converters.
764  * - When m input UChars are converted to n output bytes, then the maximum m/n
765  *   is taken into account.
766  *
767  * The number returned here does not take into account
768  * (see UCNV_GET_MAX_BYTES_FOR_STRING):
769  * - callbacks which output more than one charset character sequence per call,
770  *   like escape callbacks
771  * - initial and final non-character bytes that are output by some converters
772  *   (automatic BOMs, initial escape sequence, final SI, etc.)
773  *
774  * Examples for returned values:
775  * - SBCS charsets: 1
776  * - Shift-JIS: 2
777  * - UTF-16: 2 (2 per BMP, 4 per surrogate _pair_, BOM not counted)
778  * - UTF-8: 3 (3 per BMP, 4 per surrogate _pair_)
779  * - EBCDIC_STATEFUL (EBCDIC mixed SBCS/DBCS): 3 (SO + DBCS)
780  * - ISO-2022: 3 (always outputs UTF-8)
781  * - ISO-2022-JP: 6 (4-byte escape sequences + DBCS)
782  * - ISO-2022-CN: 8 (4-byte designator sequences + 2-byte SS2/SS3 + DBCS)
783  *
784  * @param converter The Unicode converter.
785  * @return The maximum number of bytes per UChar (16 bit code unit)
786  *    that are output by ucnv_fromUnicode(),
787  *    to be used together with UCNV_GET_MAX_BYTES_FOR_STRING
788  *    for buffer allocation.
789  *
790  * @see UCNV_GET_MAX_BYTES_FOR_STRING
791  * @see ucnv_getMinCharSize
792  * @stable ICU 2.0
793  */
794 U_CAPI int8_t U_EXPORT2
795 ucnv_getMaxCharSize(const UConverter *converter);
796 
797 /**
798  * Calculates the size of a buffer for conversion from Unicode to a charset.
799  * The calculated size is guaranteed to be sufficient for this conversion.
800  *
801  * It takes into account initial and final non-character bytes that are output
802  * by some converters.
803  * It does not take into account callbacks which output more than one charset
804  * character sequence per call, like escape callbacks.
805  * The default (substitution) callback only outputs one charset character sequence.
806  *
807  * @param length Number of UChars to be converted.
808  * @param maxCharSize Return value from ucnv_getMaxCharSize() for the converter
809  *                    that will be used.
810  * @return Size of a buffer that will be large enough to hold the output bytes of
811  *         converting length UChars with the converter that returned the maxCharSize.
812  *
813  * @see ucnv_getMaxCharSize
814  * @stable ICU 2.8
815  */
816 #define UCNV_GET_MAX_BYTES_FOR_STRING(length, maxCharSize) \
817      (((int32_t)(length)+10)*(int32_t)(maxCharSize))
818 
819 /**
820  * Returns the minimum byte length (per codepoint) for characters in this codepage.
821  * This is usually either 1 or 2.
822  * @param converter the Unicode converter
823  * @return the minimum number of bytes per codepoint allowed by this particular converter
824  * @see ucnv_getMaxCharSize
825  * @stable ICU 2.0
826  */
827 U_CAPI int8_t U_EXPORT2
828 ucnv_getMinCharSize(const UConverter *converter);
829 
830 /**
831  * Returns the display name of the converter passed in based on the Locale
832  * passed in. If the locale contains no display name, the internal ASCII
833  * name will be filled in.
834  *
835  * @param converter the Unicode converter.
836  * @param displayLocale is the specific Locale we want to localized for
837  * @param displayName user provided buffer to be filled in
838  * @param displayNameCapacity size of displayName Buffer
839  * @param err error status code
840  * @return displayNameLength number of UChar needed in displayName
841  * @see ucnv_getName
842  * @stable ICU 2.0
843  */
844 U_CAPI int32_t U_EXPORT2
845 ucnv_getDisplayName(const UConverter *converter,
846                     const char *displayLocale,
847                     UChar *displayName,
848                     int32_t displayNameCapacity,
849                     UErrorCode *err);
850 
851 /**
852  * Gets the internal, canonical name of the converter (zero-terminated).
853  * The lifetime of the returned string will be that of the converter
854  * passed to this function.
855  * @param converter the Unicode converter
856  * @param err UErrorCode status
857  * @return the internal name of the converter
858  * @see ucnv_getDisplayName
859  * @stable ICU 2.0
860  */
861 U_CAPI const char * U_EXPORT2
862 ucnv_getName(const UConverter *converter, UErrorCode *err);
863 
864 /**
865  * Gets a codepage number associated with the converter. This is not guaranteed
866  * to be the one used to create the converter. Some converters do not represent
867  * platform registered codepages and return zero for the codepage number.
868  * The error code fill-in parameter indicates if the codepage number
869  * is available.
870  * Does not check if the converter is <TT>NULL</TT> or if converter's data
871  * table is <TT>NULL</TT>.
872  *
873  * Important: The use of CCSIDs is not recommended because it is limited
874  * to only two platforms in principle and only one (UCNV_IBM) in the current
875  * ICU converter API.
876  * Also, CCSIDs are insufficient to identify IBM Unicode conversion tables precisely.
877  * For more details see ucnv_openCCSID().
878  *
879  * @param converter the Unicode converter
880  * @param err the error status code.
881  * @return If any error occurs, -1 will be returned otherwise, the codepage number
882  * will be returned
883  * @see ucnv_openCCSID
884  * @see ucnv_getPlatform
885  * @stable ICU 2.0
886  */
887 U_CAPI int32_t U_EXPORT2
888 ucnv_getCCSID(const UConverter *converter,
889               UErrorCode *err);
890 
891 /**
892  * Gets a codepage platform associated with the converter. Currently,
893  * only <TT>UCNV_IBM</TT> will be returned.
894  * Does not test if the converter is <TT>NULL</TT> or if converter's data
895  * table is <TT>NULL</TT>.
896  * @param converter the Unicode converter
897  * @param err the error status code.
898  * @return The codepage platform
899  * @stable ICU 2.0
900  */
901 U_CAPI UConverterPlatform U_EXPORT2
902 ucnv_getPlatform(const UConverter *converter,
903                  UErrorCode *err);
904 
905 /**
906  * Gets the type of the converter
907  * e.g. SBCS, MBCS, DBCS, UTF8, UTF16_BE, UTF16_LE, ISO_2022,
908  * EBCDIC_STATEFUL, LATIN_1
909  * @param converter a valid, opened converter
910  * @return the type of the converter
911  * @stable ICU 2.0
912  */
913 U_CAPI UConverterType U_EXPORT2
914 ucnv_getType(const UConverter * converter);
915 
916 /**
917  * Gets the "starter" (lead) bytes for converters of type MBCS.
918  * Will fill in an <TT>U_ILLEGAL_ARGUMENT_ERROR</TT> if converter passed in
919  * is not MBCS. Fills in an array of type UBool, with the value of the byte
920  * as offset to the array. For example, if (starters[0x20] == true) at return,
921  * it means that the byte 0x20 is a starter byte in this converter.
922  * Context pointers are always owned by the caller.
923  *
924  * @param converter a valid, opened converter of type MBCS
925  * @param starters an array of size 256 to be filled in
926  * @param err error status, <TT>U_ILLEGAL_ARGUMENT_ERROR</TT> if the
927  * converter is not a type which can return starters.
928  * @see ucnv_getType
929  * @stable ICU 2.0
930  */
931 U_CAPI void U_EXPORT2
932 ucnv_getStarters(const UConverter* converter,
933                  UBool starters[256],
934                  UErrorCode* err);
935 
936 
937 /**
938  * Selectors for Unicode sets that can be returned by ucnv_getUnicodeSet().
939  * @see ucnv_getUnicodeSet
940  * @stable ICU 2.6
941  */
942 typedef enum UConverterUnicodeSet {
943     /** Select the set of roundtrippable Unicode code points. @stable ICU 2.6 */
944     UCNV_ROUNDTRIP_SET,
945     /** Select the set of Unicode code points with roundtrip or fallback mappings. @stable ICU 4.0 */
946     UCNV_ROUNDTRIP_AND_FALLBACK_SET,
947 #ifndef U_HIDE_DEPRECATED_API
948     /**
949      * Number of UConverterUnicodeSet selectors.
950      * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
951      */
952     UCNV_SET_COUNT
953 #endif  // U_HIDE_DEPRECATED_API
954 } UConverterUnicodeSet;
955 
956 
957 /**
958  * Returns the set of Unicode code points that can be converted by an ICU converter.
959  *
960  * Returns one of several kinds of set:
961  *
962  * 1. UCNV_ROUNDTRIP_SET
963  *
964  * The set of all Unicode code points that can be roundtrip-converted
965  * (converted without any data loss) with the converter (ucnv_fromUnicode()).
966  * This set will not include code points that have fallback mappings
967  * or are only the result of reverse fallback mappings.
968  * This set will also not include PUA code points with fallbacks, although
969  * ucnv_fromUnicode() will always uses those mappings despite ucnv_setFallback().
970  * See UTR #22 "Character Mapping Markup Language"
971  * at http://www.unicode.org/reports/tr22/
972  *
973  * This is useful for example for
974  * - checking that a string or document can be roundtrip-converted with a converter,
975  *   without/before actually performing the conversion
976  * - testing if a converter can be used for text for typical text for a certain locale,
977  *   by comparing its roundtrip set with the set of ExemplarCharacters from
978  *   ICU's locale data or other sources
979  *
980  * 2. UCNV_ROUNDTRIP_AND_FALLBACK_SET
981  *
982  * The set of all Unicode code points that can be converted with the converter (ucnv_fromUnicode())
983  * when fallbacks are turned on (see ucnv_setFallback()).
984  * This set includes all code points with roundtrips and fallbacks (but not reverse fallbacks).
985  *
986  * In the future, there may be more UConverterUnicodeSet choices to select
987  * sets with different properties.
988  *
989  * @param cnv The converter for which a set is requested.
990  * @param setFillIn A valid USet *. It will be cleared by this function before
991  *            the converter's specific set is filled into the USet.
992  * @param whichSet A UConverterUnicodeSet selector;
993  *              currently UCNV_ROUNDTRIP_SET is the only supported value.
994  * @param pErrorCode ICU error code in/out parameter.
995  *                   Must fulfill U_SUCCESS before the function call.
996  *
997  * @see UConverterUnicodeSet
998  * @see uset_open
999  * @see uset_close
1000  * @stable ICU 2.6
1001  */
1002 U_CAPI void U_EXPORT2
1003 ucnv_getUnicodeSet(const UConverter *cnv,
1004                    USet *setFillIn,
1005                    UConverterUnicodeSet whichSet,
1006                    UErrorCode *pErrorCode);
1007 
1008 /**
1009  * Gets the current callback function used by the converter when an illegal
1010  *  or invalid codepage sequence is found.
1011  * Context pointers are always owned by the caller.
1012  *
1013  * @param converter the unicode converter
1014  * @param action fillin: returns the callback function pointer
1015  * @param context fillin: returns the callback's private void* context
1016  * @see ucnv_setToUCallBack
1017  * @stable ICU 2.0
1018  */
1019 U_CAPI void U_EXPORT2
1020 ucnv_getToUCallBack (const UConverter * converter,
1021                      UConverterToUCallback *action,
1022                      const void **context);
1023 
1024 /**
1025  * Gets the current callback function used by the converter when illegal
1026  * or invalid Unicode sequence is found.
1027  * Context pointers are always owned by the caller.
1028  *
1029  * @param converter the unicode converter
1030  * @param action fillin: returns the callback function pointer
1031  * @param context fillin: returns the callback's private void* context
1032  * @see ucnv_setFromUCallBack
1033  * @stable ICU 2.0
1034  */
1035 U_CAPI void U_EXPORT2
1036 ucnv_getFromUCallBack (const UConverter * converter,
1037                        UConverterFromUCallback *action,
1038                        const void **context);
1039 
1040 /**
1041  * Changes the callback function used by the converter when
1042  * an illegal or invalid sequence is found.
1043  * Context pointers are always owned by the caller.
1044  * Predefined actions and contexts can be found in the ucnv_err.h header.
1045  *
1046  * @param converter the unicode converter
1047  * @param newAction the new callback function
1048  * @param newContext the new toUnicode callback context pointer. This can be NULL.
1049  * @param oldAction fillin: returns the old callback function pointer. This can be NULL.
1050  * @param oldContext fillin: returns the old callback's private void* context. This can be NULL.
1051  * @param err The error code status
1052  * @see ucnv_getToUCallBack
1053  * @stable ICU 2.0
1054  */
1055 U_CAPI void U_EXPORT2
1056 ucnv_setToUCallBack (UConverter * converter,
1057                      UConverterToUCallback newAction,
1058                      const void* newContext,
1059                      UConverterToUCallback *oldAction,
1060                      const void** oldContext,
1061                      UErrorCode * err);
1062 
1063 /**
1064  * Changes the current callback function used by the converter when
1065  * an illegal or invalid sequence is found.
1066  * Context pointers are always owned by the caller.
1067  * Predefined actions and contexts can be found in the ucnv_err.h header.
1068  *
1069  * @param converter the unicode converter
1070  * @param newAction the new callback function
1071  * @param newContext the new fromUnicode callback context pointer. This can be NULL.
1072  * @param oldAction fillin: returns the old callback function pointer. This can be NULL.
1073  * @param oldContext fillin: returns the old callback's private void* context. This can be NULL.
1074  * @param err The error code status
1075  * @see ucnv_getFromUCallBack
1076  * @stable ICU 2.0
1077  */
1078 U_CAPI void U_EXPORT2
1079 ucnv_setFromUCallBack (UConverter * converter,
1080                        UConverterFromUCallback newAction,
1081                        const void *newContext,
1082                        UConverterFromUCallback *oldAction,
1083                        const void **oldContext,
1084                        UErrorCode * err);
1085 
1086 /**
1087  * Converts an array of unicode characters to an array of codepage
1088  * characters. This function is optimized for converting a continuous
1089  * stream of data in buffer-sized chunks, where the entire source and
1090  * target does not fit in available buffers.
1091  *
1092  * The source pointer is an in/out parameter. It starts out pointing where the
1093  * conversion is to begin, and ends up pointing after the last UChar consumed.
1094  *
1095  * Target similarly starts out pointer at the first available byte in the output
1096  * buffer, and ends up pointing after the last byte written to the output.
1097  *
1098  * The converter always attempts to consume the entire source buffer, unless
1099  * (1.) the target buffer is full, or (2.) a failing error is returned from the
1100  * current callback function.  When a successful error status has been
1101  * returned, it means that all of the source buffer has been
1102  *  consumed. At that point, the caller should reset the source and
1103  *  sourceLimit pointers to point to the next chunk.
1104  *
1105  * At the end of the stream (flush==true), the input is completely consumed
1106  * when *source==sourceLimit and no error code is set.
1107  * The converter object is then automatically reset by this function.
1108  * (This means that a converter need not be reset explicitly between data
1109  * streams if it finishes the previous stream without errors.)
1110  *
1111  * This is a <I>stateful</I> conversion. Additionally, even when all source data has
1112  * been consumed, some data may be in the converters' internal state.
1113  * Call this function repeatedly, updating the target pointers with
1114  * the next empty chunk of target in case of a
1115  * <TT>U_BUFFER_OVERFLOW_ERROR</TT>, and updating the source  pointers
1116  *  with the next chunk of source when a successful error status is
1117  * returned, until there are no more chunks of source data.
1118  * @param converter the Unicode converter
1119  * @param target I/O parameter. Input : Points to the beginning of the buffer to copy
1120  *  codepage characters to. Output : points to after the last codepage character copied
1121  *  to <TT>target</TT>.
1122  * @param targetLimit the pointer just after last of the <TT>target</TT> buffer
1123  * @param source I/O parameter, pointer to pointer to the source Unicode character buffer.
1124  * @param sourceLimit the pointer just after the last of the source buffer
1125  * @param offsets if NULL is passed, nothing will happen to it, otherwise it needs to have the same number
1126  * of allocated cells as <TT>target</TT>. Will fill in offsets from target to source pointer
1127  * e.g: <TT>offsets[3]</TT> is equal to 6, it means that the <TT>target[3]</TT> was a result of transcoding <TT>source[6]</TT>
1128  * For output data carried across calls, and other data without a specific source character
1129  * (such as from escape sequences or callbacks)  -1 will be placed for offsets.
1130  * @param flush set to <TT>true</TT> if the current source buffer is the last available
1131  * chunk of the source, <TT>false</TT> otherwise. Note that if a failing status is returned,
1132  * this function may have to be called multiple times with flush set to <TT>true</TT> until
1133  * the source buffer is consumed.
1134  * @param err the error status.  <TT>U_ILLEGAL_ARGUMENT_ERROR</TT> will be set if the
1135  * converter is <TT>NULL</TT>.
1136  * <code>U_BUFFER_OVERFLOW_ERROR</code> will be set if the target is full and there is
1137  * still data to be written to the target.
1138  * @see ucnv_fromUChars
1139  * @see ucnv_convert
1140  * @see ucnv_getMinCharSize
1141  * @see ucnv_setToUCallBack
1142  * @stable ICU 2.0
1143  */
1144 U_CAPI void U_EXPORT2
1145 ucnv_fromUnicode (UConverter * converter,
1146                   char **target,
1147                   const char *targetLimit,
1148                   const UChar ** source,
1149                   const UChar * sourceLimit,
1150                   int32_t* offsets,
1151                   UBool flush,
1152                   UErrorCode * err);
1153 
1154 /**
1155  * Converts a buffer of codepage bytes into an array of unicode UChars
1156  * characters. This function is optimized for converting a continuous
1157  * stream of data in buffer-sized chunks, where the entire source and
1158  * target does not fit in available buffers.
1159  *
1160  * The source pointer is an in/out parameter. It starts out pointing where the
1161  * conversion is to begin, and ends up pointing after the last byte of source consumed.
1162  *
1163  * Target similarly starts out pointer at the first available UChar in the output
1164  * buffer, and ends up pointing after the last UChar written to the output.
1165  * It does NOT necessarily keep UChar sequences together.
1166  *
1167  * The converter always attempts to consume the entire source buffer, unless
1168  * (1.) the target buffer is full, or (2.) a failing error is returned from the
1169  * current callback function.  When a successful error status has been
1170  * returned, it means that all of the source buffer has been
1171  *  consumed. At that point, the caller should reset the source and
1172  *  sourceLimit pointers to point to the next chunk.
1173  *
1174  * At the end of the stream (flush==true), the input is completely consumed
1175  * when *source==sourceLimit and no error code is set
1176  * The converter object is then automatically reset by this function.
1177  * (This means that a converter need not be reset explicitly between data
1178  * streams if it finishes the previous stream without errors.)
1179  *
1180  * This is a <I>stateful</I> conversion. Additionally, even when all source data has
1181  * been consumed, some data may be in the converters' internal state.
1182  * Call this function repeatedly, updating the target pointers with
1183  * the next empty chunk of target in case of a
1184  * <TT>U_BUFFER_OVERFLOW_ERROR</TT>, and updating the source  pointers
1185  *  with the next chunk of source when a successful error status is
1186  * returned, until there are no more chunks of source data.
1187  * @param converter the Unicode converter
1188  * @param target I/O parameter. Input : Points to the beginning of the buffer to copy
1189  *  UChars into. Output : points to after the last UChar copied.
1190  * @param targetLimit the pointer just after the end of the <TT>target</TT> buffer
1191  * @param source I/O parameter, pointer to pointer to the source codepage buffer.
1192  * @param sourceLimit the pointer to the byte after the end of the source buffer
1193  * @param offsets if NULL is passed, nothing will happen to it, otherwise it needs to have the same number
1194  * of allocated cells as <TT>target</TT>. Will fill in offsets from target to source pointer
1195  * e.g: <TT>offsets[3]</TT> is equal to 6, it means that the <TT>target[3]</TT> was a result of transcoding <TT>source[6]</TT>
1196  * For output data carried across calls, and other data without a specific source character
1197  * (such as from escape sequences or callbacks)  -1 will be placed for offsets.
1198  * @param flush set to <TT>true</TT> if the current source buffer is the last available
1199  * chunk of the source, <TT>false</TT> otherwise. Note that if a failing status is returned,
1200  * this function may have to be called multiple times with flush set to <TT>true</TT> until
1201  * the source buffer is consumed.
1202  * @param err the error status.  <TT>U_ILLEGAL_ARGUMENT_ERROR</TT> will be set if the
1203  * converter is <TT>NULL</TT>.
1204  * <code>U_BUFFER_OVERFLOW_ERROR</code> will be set if the target is full and there is
1205  * still data to be written to the target.
1206  * @see ucnv_fromUChars
1207  * @see ucnv_convert
1208  * @see ucnv_getMinCharSize
1209  * @see ucnv_setFromUCallBack
1210  * @see ucnv_getNextUChar
1211  * @stable ICU 2.0
1212  */
1213 U_CAPI void U_EXPORT2
1214 ucnv_toUnicode(UConverter *converter,
1215                UChar **target,
1216                const UChar *targetLimit,
1217                const char **source,
1218                const char *sourceLimit,
1219                int32_t *offsets,
1220                UBool flush,
1221                UErrorCode *err);
1222 
1223 /**
1224  * Convert the Unicode string into a codepage string using an existing UConverter.
1225  * The output string is NUL-terminated if possible.
1226  *
1227  * This function is a more convenient but less powerful version of ucnv_fromUnicode().
1228  * It is only useful for whole strings, not for streaming conversion.
1229  *
1230  * The maximum output buffer capacity required (barring output from callbacks) will be
1231  * UCNV_GET_MAX_BYTES_FOR_STRING(srcLength, ucnv_getMaxCharSize(cnv)).
1232  *
1233  * @param cnv the converter object to be used (ucnv_resetFromUnicode() will be called)
1234  * @param src the input Unicode string
1235  * @param srcLength the input string length, or -1 if NUL-terminated
1236  * @param dest destination string buffer, can be NULL if destCapacity==0
1237  * @param destCapacity the number of chars available at dest
1238  * @param pErrorCode normal ICU error code;
1239  *                  common error codes that may be set by this function include
1240  *                  U_BUFFER_OVERFLOW_ERROR, U_STRING_NOT_TERMINATED_WARNING,
1241  *                  U_ILLEGAL_ARGUMENT_ERROR, and conversion errors
1242  * @return the length of the output string, not counting the terminating NUL;
1243  *         if the length is greater than destCapacity, then the string will not fit
1244  *         and a buffer of the indicated length would need to be passed in
1245  * @see ucnv_fromUnicode
1246  * @see ucnv_convert
1247  * @see UCNV_GET_MAX_BYTES_FOR_STRING
1248  * @stable ICU 2.0
1249  */
1250 U_CAPI int32_t U_EXPORT2
1251 ucnv_fromUChars(UConverter *cnv,
1252                 char *dest, int32_t destCapacity,
1253                 const UChar *src, int32_t srcLength,
1254                 UErrorCode *pErrorCode);
1255 
1256 /**
1257  * Convert the codepage string into a Unicode string using an existing UConverter.
1258  * The output string is NUL-terminated if possible.
1259  *
1260  * This function is a more convenient but less powerful version of ucnv_toUnicode().
1261  * It is only useful for whole strings, not for streaming conversion.
1262  *
1263  * The maximum output buffer capacity required (barring output from callbacks) will be
1264  * 2*srcLength (each char may be converted into a surrogate pair).
1265  *
1266  * @param cnv the converter object to be used (ucnv_resetToUnicode() will be called)
1267  * @param src the input codepage string
1268  * @param srcLength the input string length, or -1 if NUL-terminated
1269  * @param dest destination string buffer, can be NULL if destCapacity==0
1270  * @param destCapacity the number of UChars available at dest
1271  * @param pErrorCode normal ICU error code;
1272  *                  common error codes that may be set by this function include
1273  *                  U_BUFFER_OVERFLOW_ERROR, U_STRING_NOT_TERMINATED_WARNING,
1274  *                  U_ILLEGAL_ARGUMENT_ERROR, and conversion errors
1275  * @return the length of the output string, not counting the terminating NUL;
1276  *         if the length is greater than destCapacity, then the string will not fit
1277  *         and a buffer of the indicated length would need to be passed in
1278  * @see ucnv_toUnicode
1279  * @see ucnv_convert
1280  * @stable ICU 2.0
1281  */
1282 U_CAPI int32_t U_EXPORT2
1283 ucnv_toUChars(UConverter *cnv,
1284               UChar *dest, int32_t destCapacity,
1285               const char *src, int32_t srcLength,
1286               UErrorCode *pErrorCode);
1287 
1288 /**
1289  * Convert a codepage buffer into Unicode one character at a time.
1290  * The input is completely consumed when the U_INDEX_OUTOFBOUNDS_ERROR is set.
1291  *
1292  * Advantage compared to ucnv_toUnicode() or ucnv_toUChars():
1293  * - Faster for small amounts of data, for most converters, e.g.,
1294  *   US-ASCII, ISO-8859-1, UTF-8/16/32, and most "normal" charsets.
1295  *   (For complex converters, e.g., SCSU, UTF-7 and ISO 2022 variants,
1296  *    it uses ucnv_toUnicode() internally.)
1297  * - Convenient.
1298  *
1299  * Limitations compared to ucnv_toUnicode():
1300  * - Always assumes flush=true.
1301  *   This makes ucnv_getNextUChar() unsuitable for "streaming" conversion,
1302  *   that is, for where the input is supplied in multiple buffers,
1303  *   because ucnv_getNextUChar() will assume the end of the input at the end
1304  *   of the first buffer.
1305  * - Does not provide offset output.
1306  *
1307  * It is possible to "mix" ucnv_getNextUChar() and ucnv_toUnicode() because
1308  * ucnv_getNextUChar() uses the current state of the converter
1309  * (unlike ucnv_toUChars() which always resets first).
1310  * However, if ucnv_getNextUChar() is called after ucnv_toUnicode()
1311  * stopped in the middle of a character sequence (with flush=false),
1312  * then ucnv_getNextUChar() will always use the slower ucnv_toUnicode()
1313  * internally until the next character boundary.
1314  * (This is new in ICU 2.6. In earlier releases, ucnv_getNextUChar() had to
1315  * start at a character boundary.)
1316  *
1317  * Instead of using ucnv_getNextUChar(), it is recommended
1318  * to convert using ucnv_toUnicode() or ucnv_toUChars()
1319  * and then iterate over the text using U16_NEXT() or a UCharIterator (uiter.h)
1320  * or a C++ CharacterIterator or similar.
1321  * This allows streaming conversion and offset output, for example.
1322  *
1323  * <p>Handling of surrogate pairs and supplementary-plane code points:<br>
1324  * There are two different kinds of codepages that provide mappings for surrogate characters:
1325  * <ul>
1326  *   <li>Codepages like UTF-8, UTF-32, and GB 18030 provide direct representations for Unicode
1327  *       code points U+10000-U+10ffff as well as for single surrogates U+d800-U+dfff.
1328  *       Each valid sequence will result in exactly one returned code point.
1329  *       If a sequence results in a single surrogate, then that will be returned
1330  *       by itself, even if a neighboring sequence encodes the matching surrogate.</li>
1331  *   <li>Codepages like SCSU and LMBCS (and UTF-16) provide direct representations only for BMP code points
1332  *       including surrogates. Code points in supplementary planes are represented with
1333  *       two sequences, each encoding a surrogate.
1334  *       For these codepages, matching pairs of surrogates will be combined into single
1335  *       code points for returning from this function.
1336  *       (Note that SCSU is actually a mix of these codepage types.)</li>
1337  * </ul></p>
1338  *
1339  * @param converter an open UConverter
1340  * @param source the address of a pointer to the codepage buffer, will be
1341  *  updated to point after the bytes consumed in the conversion call.
1342  * @param sourceLimit points to the end of the input buffer
1343  * @param err fills in error status (see ucnv_toUnicode)
1344  * <code>U_INDEX_OUTOFBOUNDS_ERROR</code> will be set if the input
1345  * is empty or does not convert to any output (e.g.: pure state-change
1346  * codes SI/SO, escape sequences for ISO 2022,
1347  * or if the callback did not output anything, ...).
1348  * This function will not set a <code>U_BUFFER_OVERFLOW_ERROR</code> because
1349  *  the "buffer" is the return code. However, there might be subsequent output
1350  *  stored in the converter object
1351  * that will be returned in following calls to this function.
1352  * @return a UChar32 resulting from the partial conversion of source
1353  * @see ucnv_toUnicode
1354  * @see ucnv_toUChars
1355  * @see ucnv_convert
1356  * @stable ICU 2.0
1357  */
1358 U_CAPI UChar32 U_EXPORT2
1359 ucnv_getNextUChar(UConverter * converter,
1360                   const char **source,
1361                   const char * sourceLimit,
1362                   UErrorCode * err);
1363 
1364 /**
1365  * Convert from one external charset to another using two existing UConverters.
1366  * Internally, two conversions - ucnv_toUnicode() and ucnv_fromUnicode() -
1367  * are used, "pivoting" through 16-bit Unicode.
1368  *
1369  * Important: For streaming conversion (multiple function calls for successive
1370  * parts of a text stream), the caller must provide a pivot buffer explicitly,
1371  * and must preserve the pivot buffer and associated pointers from one
1372  * call to another. (The buffer may be moved if its contents and the relative
1373  * pointer positions are preserved.)
1374  *
1375  * There is a similar function, ucnv_convert(),
1376  * which has the following limitations:
1377  * - it takes charset names, not converter objects, so that
1378  *   - two converters are opened for each call
1379  *   - only single-string conversion is possible, not streaming operation
1380  * - it does not provide enough information to find out,
1381  *   in case of failure, whether the toUnicode or
1382  *   the fromUnicode conversion failed
1383  *
1384  * By contrast, ucnv_convertEx()
1385  * - takes UConverter parameters instead of charset names
1386  * - fully exposes the pivot buffer for streaming conversion and complete error handling
1387  *
1388  * ucnv_convertEx() also provides further convenience:
1389  * - an option to reset the converters at the beginning
1390  *   (if reset==true, see parameters;
1391  *    also sets *pivotTarget=*pivotSource=pivotStart)
1392  * - allow NUL-terminated input
1393  *   (only a single NUL byte, will not work for charsets with multi-byte NULs)
1394  *   (if sourceLimit==NULL, see parameters)
1395  * - terminate with a NUL on output
1396  *   (only a single NUL byte, not useful for charsets with multi-byte NULs),
1397  *   or set U_STRING_NOT_TERMINATED_WARNING if the output exactly fills
1398  *   the target buffer
1399  * - the pivot buffer can be provided internally;
1400  *   possible only for whole-string conversion, not streaming conversion;
1401  *   in this case, the caller will not be able to get details about where an
1402  *   error occurred
1403  *   (if pivotStart==NULL, see below)
1404  *
1405  * The function returns when one of the following is true:
1406  * - the entire source text has been converted successfully to the target buffer
1407  * - a target buffer overflow occurred (U_BUFFER_OVERFLOW_ERROR)
1408  * - a conversion error occurred
1409  *   (other U_FAILURE(), see description of pErrorCode)
1410  *
1411  * Limitation compared to the direct use of
1412  * ucnv_fromUnicode() and ucnv_toUnicode():
1413  * ucnv_convertEx() does not provide offset information.
1414  *
1415  * Limitation compared to ucnv_fromUChars() and ucnv_toUChars():
1416  * ucnv_convertEx() does not support preflighting directly.
1417  *
1418  * Sample code for converting a single string from
1419  * one external charset to UTF-8, ignoring the location of errors:
1420  *
1421  * \code
1422  * int32_t
1423  * myToUTF8(UConverter *cnv,
1424  *          const char *s, int32_t length,
1425  *          char *u8, int32_t capacity,
1426  *          UErrorCode *pErrorCode) {
1427  *     UConverter *utf8Cnv;
1428  *     char *target;
1429  *
1430  *     if(U_FAILURE(*pErrorCode)) {
1431  *         return 0;
1432  *     }
1433  *
1434  *     utf8Cnv=myGetCachedUTF8Converter(pErrorCode);
1435  *     if(U_FAILURE(*pErrorCode)) {
1436  *         return 0;
1437  *     }
1438  *
1439  *     if(length<0) {
1440  *         length=strlen(s);
1441  *     }
1442  *     target=u8;
1443  *     ucnv_convertEx(utf8Cnv, cnv,
1444  *                    &target, u8+capacity,
1445  *                    &s, s+length,
1446  *                    NULL, NULL, NULL, NULL,
1447  *                    true, true,
1448  *                    pErrorCode);
1449  *
1450  *     myReleaseCachedUTF8Converter(utf8Cnv);
1451  *
1452  *     // return the output string length, but without preflighting
1453  *     return (int32_t)(target-u8);
1454  * }
1455  * \endcode
1456  *
1457  * @param targetCnv     Output converter, used to convert from the UTF-16 pivot
1458  *                      to the target using ucnv_fromUnicode().
1459  * @param sourceCnv     Input converter, used to convert from the source to
1460  *                      the UTF-16 pivot using ucnv_toUnicode().
1461  * @param target        I/O parameter, same as for ucnv_fromUChars().
1462  *                      Input: *target points to the beginning of the target buffer.
1463  *                      Output: *target points to the first unit after the last char written.
1464  * @param targetLimit   Pointer to the first unit after the target buffer.
1465  * @param source        I/O parameter, same as for ucnv_toUChars().
1466  *                      Input: *source points to the beginning of the source buffer.
1467  *                      Output: *source points to the first unit after the last char read.
1468  * @param sourceLimit   Pointer to the first unit after the source buffer.
1469  * @param pivotStart    Pointer to the UTF-16 pivot buffer. If pivotStart==NULL,
1470  *                      then an internal buffer is used and the other pivot
1471  *                      arguments are ignored and can be NULL as well.
1472  * @param pivotSource   I/O parameter, same as source in ucnv_fromUChars() for
1473  *                      conversion from the pivot buffer to the target buffer.
1474  * @param pivotTarget   I/O parameter, same as target in ucnv_toUChars() for
1475  *                      conversion from the source buffer to the pivot buffer.
1476  *                      It must be pivotStart<=*pivotSource<=*pivotTarget<=pivotLimit
1477  *                      and pivotStart<pivotLimit (unless pivotStart==NULL).
1478  * @param pivotLimit    Pointer to the first unit after the pivot buffer.
1479  * @param reset         If true, then ucnv_resetToUnicode(sourceCnv) and
1480  *                      ucnv_resetFromUnicode(targetCnv) are called, and the
1481  *                      pivot pointers are reset (*pivotTarget=*pivotSource=pivotStart).
1482  * @param flush         If true, indicates the end of the input.
1483  *                      Passed directly to ucnv_toUnicode(), and carried over to
1484  *                      ucnv_fromUnicode() when the source is empty as well.
1485  * @param pErrorCode    ICU error code in/out parameter.
1486  *                      Must fulfill U_SUCCESS before the function call.
1487  *                      U_BUFFER_OVERFLOW_ERROR always refers to the target buffer
1488  *                      because overflows into the pivot buffer are handled internally.
1489  *                      Other conversion errors are from the source-to-pivot
1490  *                      conversion if *pivotSource==pivotStart, otherwise from
1491  *                      the pivot-to-target conversion.
1492  *
1493  * @see ucnv_convert
1494  * @see ucnv_fromAlgorithmic
1495  * @see ucnv_toAlgorithmic
1496  * @see ucnv_fromUnicode
1497  * @see ucnv_toUnicode
1498  * @see ucnv_fromUChars
1499  * @see ucnv_toUChars
1500  * @stable ICU 2.6
1501  */
1502 U_CAPI void U_EXPORT2
1503 ucnv_convertEx(UConverter *targetCnv, UConverter *sourceCnv,
1504                char **target, const char *targetLimit,
1505                const char **source, const char *sourceLimit,
1506                UChar *pivotStart, UChar **pivotSource,
1507                UChar **pivotTarget, const UChar *pivotLimit,
1508                UBool reset, UBool flush,
1509                UErrorCode *pErrorCode);
1510 
1511 /**
1512  * Convert from one external charset to another.
1513  * Internally, two converters are opened according to the name arguments,
1514  * then the text is converted to and from the 16-bit Unicode "pivot"
1515  * using ucnv_convertEx(), then the converters are closed again.
1516  *
1517  * This is a convenience function, not an efficient way to convert a lot of text:
1518  * ucnv_convert()
1519  * - takes charset names, not converter objects, so that
1520  *   - two converters are opened for each call
1521  *   - only single-string conversion is possible, not streaming operation
1522  * - does not provide enough information to find out,
1523  *   in case of failure, whether the toUnicode or
1524  *   the fromUnicode conversion failed
1525  * - allows NUL-terminated input
1526  *   (only a single NUL byte, will not work for charsets with multi-byte NULs)
1527  *   (if sourceLength==-1, see parameters)
1528  * - terminate with a NUL on output
1529  *   (only a single NUL byte, not useful for charsets with multi-byte NULs),
1530  *   or set U_STRING_NOT_TERMINATED_WARNING if the output exactly fills
1531  *   the target buffer
1532  * - a pivot buffer is provided internally
1533  *
1534  * The function returns when one of the following is true:
1535  * - the entire source text has been converted successfully to the target buffer
1536  *   and either the target buffer is terminated with a single NUL byte
1537  *   or the error code is set to U_STRING_NOT_TERMINATED_WARNING
1538  * - a target buffer overflow occurred (U_BUFFER_OVERFLOW_ERROR)
1539  *   and the full output string length is returned ("preflighting")
1540  * - a conversion error occurred
1541  *   (other U_FAILURE(), see description of pErrorCode)
1542  *
1543  * @param toConverterName   The name of the converter that is used to convert
1544  *                          from the UTF-16 pivot buffer to the target.
1545  * @param fromConverterName The name of the converter that is used to convert
1546  *                          from the source to the UTF-16 pivot buffer.
1547  * @param target            Pointer to the output buffer.
1548  * @param targetCapacity    Capacity of the target, in bytes.
1549  * @param source            Pointer to the input buffer.
1550  * @param sourceLength      Length of the input text, in bytes, or -1 for NUL-terminated input.
1551  * @param pErrorCode        ICU error code in/out parameter.
1552  *                          Must fulfill U_SUCCESS before the function call.
1553  * @return Length of the complete output text in bytes, even if it exceeds the targetCapacity
1554  *         and a U_BUFFER_OVERFLOW_ERROR is set.
1555  *
1556  * @see ucnv_convertEx
1557  * @see ucnv_fromAlgorithmic
1558  * @see ucnv_toAlgorithmic
1559  * @see ucnv_fromUnicode
1560  * @see ucnv_toUnicode
1561  * @see ucnv_fromUChars
1562  * @see ucnv_toUChars
1563  * @see ucnv_getNextUChar
1564  * @stable ICU 2.0
1565  */
1566 U_CAPI int32_t U_EXPORT2
1567 ucnv_convert(const char *toConverterName,
1568              const char *fromConverterName,
1569              char *target,
1570              int32_t targetCapacity,
1571              const char *source,
1572              int32_t sourceLength,
1573              UErrorCode *pErrorCode);
1574 
1575 /**
1576  * Convert from one external charset to another.
1577  * Internally, the text is converted to and from the 16-bit Unicode "pivot"
1578  * using ucnv_convertEx(). ucnv_toAlgorithmic() works exactly like ucnv_convert()
1579  * except that the two converters need not be looked up and opened completely.
1580  *
1581  * The source-to-pivot conversion uses the cnv converter parameter.
1582  * The pivot-to-target conversion uses a purely algorithmic converter
1583  * according to the specified type, e.g., UCNV_UTF8 for a UTF-8 converter.
1584  *
1585  * Internally, the algorithmic converter is opened and closed for each
1586  * function call, which is more efficient than using the public ucnv_open()
1587  * but somewhat less efficient than only resetting an existing converter
1588  * and using ucnv_convertEx().
1589  *
1590  * This function is more convenient than ucnv_convertEx() for single-string
1591  * conversions, especially when "preflighting" is desired (returning the length
1592  * of the complete output even if it does not fit into the target buffer;
1593  * see the User Guide Strings chapter). See ucnv_convert() for details.
1594  *
1595  * @param algorithmicType   UConverterType constant identifying the desired target
1596  *                          charset as a purely algorithmic converter.
1597  *                          Those are converters for Unicode charsets like
1598  *                          UTF-8, BOCU-1, SCSU, UTF-7, IMAP-mailbox-name, etc.,
1599  *                          as well as US-ASCII and ISO-8859-1.
1600  * @param cnv               The converter that is used to convert
1601  *                          from the source to the UTF-16 pivot buffer.
1602  * @param target            Pointer to the output buffer.
1603  * @param targetCapacity    Capacity of the target, in bytes.
1604  * @param source            Pointer to the input buffer.
1605  * @param sourceLength      Length of the input text, in bytes
1606  * @param pErrorCode        ICU error code in/out parameter.
1607  *                          Must fulfill U_SUCCESS before the function call.
1608  * @return Length of the complete output text in bytes, even if it exceeds the targetCapacity
1609  *         and a U_BUFFER_OVERFLOW_ERROR is set.
1610  *
1611  * @see ucnv_fromAlgorithmic
1612  * @see ucnv_convert
1613  * @see ucnv_convertEx
1614  * @see ucnv_fromUnicode
1615  * @see ucnv_toUnicode
1616  * @see ucnv_fromUChars
1617  * @see ucnv_toUChars
1618  * @stable ICU 2.6
1619  */
1620 U_CAPI int32_t U_EXPORT2
1621 ucnv_toAlgorithmic(UConverterType algorithmicType,
1622                    UConverter *cnv,
1623                    char *target, int32_t targetCapacity,
1624                    const char *source, int32_t sourceLength,
1625                    UErrorCode *pErrorCode);
1626 
1627 /**
1628  * Convert from one external charset to another.
1629  * Internally, the text is converted to and from the 16-bit Unicode "pivot"
1630  * using ucnv_convertEx(). ucnv_fromAlgorithmic() works exactly like ucnv_convert()
1631  * except that the two converters need not be looked up and opened completely.
1632  *
1633  * The source-to-pivot conversion uses a purely algorithmic converter
1634  * according to the specified type, e.g., UCNV_UTF8 for a UTF-8 converter.
1635  * The pivot-to-target conversion uses the cnv converter parameter.
1636  *
1637  * Internally, the algorithmic converter is opened and closed for each
1638  * function call, which is more efficient than using the public ucnv_open()
1639  * but somewhat less efficient than only resetting an existing converter
1640  * and using ucnv_convertEx().
1641  *
1642  * This function is more convenient than ucnv_convertEx() for single-string
1643  * conversions, especially when "preflighting" is desired (returning the length
1644  * of the complete output even if it does not fit into the target buffer;
1645  * see the User Guide Strings chapter). See ucnv_convert() for details.
1646  *
1647  * @param cnv               The converter that is used to convert
1648  *                          from the UTF-16 pivot buffer to the target.
1649  * @param algorithmicType   UConverterType constant identifying the desired source
1650  *                          charset as a purely algorithmic converter.
1651  *                          Those are converters for Unicode charsets like
1652  *                          UTF-8, BOCU-1, SCSU, UTF-7, IMAP-mailbox-name, etc.,
1653  *                          as well as US-ASCII and ISO-8859-1.
1654  * @param target            Pointer to the output buffer.
1655  * @param targetCapacity    Capacity of the target, in bytes.
1656  * @param source            Pointer to the input buffer.
1657  * @param sourceLength      Length of the input text, in bytes
1658  * @param pErrorCode        ICU error code in/out parameter.
1659  *                          Must fulfill U_SUCCESS before the function call.
1660  * @return Length of the complete output text in bytes, even if it exceeds the targetCapacity
1661  *         and a U_BUFFER_OVERFLOW_ERROR is set.
1662  *
1663  * @see ucnv_fromAlgorithmic
1664  * @see ucnv_convert
1665  * @see ucnv_convertEx
1666  * @see ucnv_fromUnicode
1667  * @see ucnv_toUnicode
1668  * @see ucnv_fromUChars
1669  * @see ucnv_toUChars
1670  * @stable ICU 2.6
1671  */
1672 U_CAPI int32_t U_EXPORT2
1673 ucnv_fromAlgorithmic(UConverter *cnv,
1674                      UConverterType algorithmicType,
1675                      char *target, int32_t targetCapacity,
1676                      const char *source, int32_t sourceLength,
1677                      UErrorCode *pErrorCode);
1678 
1679 /**
1680  * Frees up memory occupied by unused, cached converter shared data.
1681  *
1682  * @return the number of cached converters successfully deleted
1683  * @see ucnv_close
1684  * @stable ICU 2.0
1685  */
1686 U_CAPI int32_t U_EXPORT2
1687 ucnv_flushCache(void);
1688 
1689 /**
1690  * Returns the number of available converters, as per the alias file.
1691  *
1692  * @return the number of available converters
1693  * @see ucnv_getAvailableName
1694  * @stable ICU 2.0
1695  */
1696 U_CAPI int32_t U_EXPORT2
1697 ucnv_countAvailable(void);
1698 
1699 /**
1700  * Gets the canonical converter name of the specified converter from a list of
1701  * all available converters contained in the alias file. All converters
1702  * in this list can be opened.
1703  *
1704  * @param n the index to a converter available on the system (in the range <TT>[0..ucnv_countAvailable()]</TT>)
1705  * @return a pointer a string (library owned), or <TT>NULL</TT> if the index is out of bounds.
1706  * @see ucnv_countAvailable
1707  * @stable ICU 2.0
1708  */
1709 U_CAPI const char* U_EXPORT2
1710 ucnv_getAvailableName(int32_t n);
1711 
1712 /**
1713  * Returns a UEnumeration to enumerate all of the canonical converter
1714  * names, as per the alias file, regardless of the ability to open each
1715  * converter.
1716  *
1717  * @return A UEnumeration object for getting all the recognized canonical
1718  *   converter names.
1719  * @see ucnv_getAvailableName
1720  * @see uenum_close
1721  * @see uenum_next
1722  * @stable ICU 2.4
1723  */
1724 U_CAPI UEnumeration * U_EXPORT2
1725 ucnv_openAllNames(UErrorCode *pErrorCode);
1726 
1727 /**
1728  * Gives the number of aliases for a given converter or alias name.
1729  * If the alias is ambiguous, then the preferred converter is used
1730  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
1731  * This method only enumerates the listed entries in the alias file.
1732  * @param alias alias name
1733  * @param pErrorCode error status
1734  * @return number of names on alias list for given alias
1735  * @stable ICU 2.0
1736  */
1737 U_CAPI uint16_t U_EXPORT2
1738 ucnv_countAliases(const char *alias, UErrorCode *pErrorCode);
1739 
1740 /**
1741  * Gives the name of the alias at given index of alias list.
1742  * This method only enumerates the listed entries in the alias file.
1743  * If the alias is ambiguous, then the preferred converter is used
1744  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
1745  * @param alias alias name
1746  * @param n index in alias list
1747  * @param pErrorCode result of operation
1748  * @return returns the name of the alias at given index
1749  * @see ucnv_countAliases
1750  * @stable ICU 2.0
1751  */
1752 U_CAPI const char * U_EXPORT2
1753 ucnv_getAlias(const char *alias, uint16_t n, UErrorCode *pErrorCode);
1754 
1755 /**
1756  * Fill-up the list of alias names for the given alias.
1757  * This method only enumerates the listed entries in the alias file.
1758  * If the alias is ambiguous, then the preferred converter is used
1759  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
1760  * @param alias alias name
1761  * @param aliases fill-in list, aliases is a pointer to an array of
1762  *        <code>ucnv_countAliases()</code> string-pointers
1763  *        (<code>const char *</code>) that will be filled in.
1764  *        The strings themselves are owned by the library.
1765  * @param pErrorCode result of operation
1766  * @stable ICU 2.0
1767  */
1768 U_CAPI void U_EXPORT2
1769 ucnv_getAliases(const char *alias, const char **aliases, UErrorCode *pErrorCode);
1770 
1771 /**
1772  * Return a new UEnumeration object for enumerating all the
1773  * alias names for a given converter that are recognized by a standard.
1774  * This method only enumerates the listed entries in the alias file.
1775  * The convrtrs.txt file can be modified to change the results of
1776  * this function.
1777  * The first result in this list is the same result given by
1778  * <code>ucnv_getStandardName</code>, which is the default alias for
1779  * the specified standard name. The returned object must be closed with
1780  * <code>uenum_close</code> when you are done with the object.
1781  *
1782  * @param convName original converter name
1783  * @param standard name of the standard governing the names; MIME and IANA
1784  *      are such standards
1785  * @param pErrorCode The error code
1786  * @return A UEnumeration object for getting all aliases that are recognized
1787  *      by a standard. If any of the parameters are invalid, NULL
1788  *      is returned.
1789  * @see ucnv_getStandardName
1790  * @see uenum_close
1791  * @see uenum_next
1792  * @stable ICU 2.2
1793  */
1794 U_CAPI UEnumeration * U_EXPORT2
1795 ucnv_openStandardNames(const char *convName,
1796                        const char *standard,
1797                        UErrorCode *pErrorCode);
1798 
1799 /**
1800  * Gives the number of standards associated to converter names.
1801  * @return number of standards
1802  * @stable ICU 2.0
1803  */
1804 U_CAPI uint16_t U_EXPORT2
1805 ucnv_countStandards(void);
1806 
1807 /**
1808  * Gives the name of the standard at given index of standard list.
1809  * @param n index in standard list
1810  * @param pErrorCode result of operation
1811  * @return returns the name of the standard at given index. Owned by the library.
1812  * @stable ICU 2.0
1813  */
1814 U_CAPI const char * U_EXPORT2
1815 ucnv_getStandard(uint16_t n, UErrorCode *pErrorCode);
1816 
1817 /**
1818  * Returns a standard name for a given converter name.
1819  * <p>
1820  * Example alias table:<br>
1821  * conv alias1 { STANDARD1 } alias2 { STANDARD1* }
1822  * <p>
1823  * Result of ucnv_getStandardName("conv", "STANDARD1") from example
1824  * alias table:<br>
1825  * <b>"alias2"</b>
1826  *
1827  * @param name original converter name
1828  * @param standard name of the standard governing the names; MIME and IANA
1829  *        are such standards
1830  * @param pErrorCode result of operation
1831  * @return returns the standard converter name;
1832  *         if a standard converter name cannot be determined,
1833  *         then <code>NULL</code> is returned. Owned by the library.
1834  * @stable ICU 2.0
1835  */
1836 U_CAPI const char * U_EXPORT2
1837 ucnv_getStandardName(const char *name, const char *standard, UErrorCode *pErrorCode);
1838 
1839 /**
1840  * This function will return the internal canonical converter name of the
1841  * tagged alias. This is the opposite of ucnv_openStandardNames, which
1842  * returns the tagged alias given the canonical name.
1843  * <p>
1844  * Example alias table:<br>
1845  * conv alias1 { STANDARD1 } alias2 { STANDARD1* }
1846  * <p>
1847  * Result of ucnv_getStandardName("alias1", "STANDARD1") from example
1848  * alias table:<br>
1849  * <b>"conv"</b>
1850  *
1851  * @return returns the canonical converter name;
1852  *         if a standard or alias name cannot be determined,
1853  *         then <code>NULL</code> is returned. The returned string is
1854  *         owned by the library.
1855  * @see ucnv_getStandardName
1856  * @stable ICU 2.4
1857  */
1858 U_CAPI const char * U_EXPORT2
1859 ucnv_getCanonicalName(const char *alias, const char *standard, UErrorCode *pErrorCode);
1860 
1861 /**
1862  * Returns the current default converter name. If you want to open
1863  * a default converter, you do not need to use this function.
1864  * It is faster if you pass a NULL argument to ucnv_open the
1865  * default converter.
1866  *
1867  * If U_CHARSET_IS_UTF8 is defined to 1 in utypes.h then this function
1868  * always returns "UTF-8".
1869  *
1870  * @return returns the current default converter name.
1871  *         Storage owned by the library
1872  * @see ucnv_setDefaultName
1873  * @stable ICU 2.0
1874  */
1875 U_CAPI const char * U_EXPORT2
1876 ucnv_getDefaultName(void);
1877 
1878 #ifndef U_HIDE_SYSTEM_API
1879 /**
1880  * This function is not thread safe. DO NOT call this function when ANY ICU
1881  * function is being used from more than one thread! This function sets the
1882  * current default converter name. If this function needs to be called, it
1883  * should be called during application initialization. Most of the time, the
1884  * results from ucnv_getDefaultName() or ucnv_open with a NULL string argument
1885  * is sufficient for your application.
1886  *
1887  * If U_CHARSET_IS_UTF8 is defined to 1 in utypes.h then this function
1888  * does nothing.
1889  *
1890  * @param name the converter name to be the default (must be known by ICU).
1891  * @see ucnv_getDefaultName
1892  * @system
1893  * @stable ICU 2.0
1894  */
1895 U_CAPI void U_EXPORT2
1896 ucnv_setDefaultName(const char *name);
1897 #endif  /* U_HIDE_SYSTEM_API */
1898 
1899 /**
1900  * Fixes the backslash character mismapping.  For example, in SJIS, the backslash
1901  * character in the ASCII portion is also used to represent the yen currency sign.
1902  * When mapping from Unicode character 0x005C, it's unclear whether to map the
1903  * character back to yen or backslash in SJIS.  This function will take the input
1904  * buffer and replace all the yen sign characters with backslash.  This is necessary
1905  * when the user tries to open a file with the input buffer on Windows.
1906  * This function will test the converter to see whether such mapping is
1907  * required.  You can sometimes avoid using this function by using the correct version
1908  * of Shift-JIS.
1909  *
1910  * @param cnv The converter representing the target codepage.
1911  * @param source the input buffer to be fixed
1912  * @param sourceLen the length of the input buffer
1913  * @see ucnv_isAmbiguous
1914  * @stable ICU 2.0
1915  */
1916 U_CAPI void U_EXPORT2
1917 ucnv_fixFileSeparator(const UConverter *cnv, UChar *source, int32_t sourceLen);
1918 
1919 /**
1920  * Determines if the converter contains ambiguous mappings of the same
1921  * character or not.
1922  * @param cnv the converter to be tested
1923  * @return true if the converter contains ambiguous mapping of the same
1924  * character, false otherwise.
1925  * @stable ICU 2.0
1926  */
1927 U_CAPI UBool U_EXPORT2
1928 ucnv_isAmbiguous(const UConverter *cnv);
1929 
1930 /**
1931  * Sets the converter to use fallback mappings or not.
1932  * Regardless of this flag, the converter will always use
1933  * fallbacks from Unicode Private Use code points, as well as
1934  * reverse fallbacks (to Unicode).
1935  * For details see ".ucm File Format"
1936  * in the Conversion Data chapter of the ICU User Guide:
1937  * https://unicode-org.github.io/icu/userguide/conversion/data.html#ucm-file-format
1938  *
1939  * @param cnv The converter to set the fallback mapping usage on.
1940  * @param usesFallback true if the user wants the converter to take advantage of the fallback
1941  * mapping, false otherwise.
1942  * @stable ICU 2.0
1943  * @see ucnv_usesFallback
1944  */
1945 U_CAPI void U_EXPORT2
1946 ucnv_setFallback(UConverter *cnv, UBool usesFallback);
1947 
1948 /**
1949  * Determines if the converter uses fallback mappings or not.
1950  * This flag has restrictions, see ucnv_setFallback().
1951  *
1952  * @param cnv The converter to be tested
1953  * @return true if the converter uses fallback, false otherwise.
1954  * @stable ICU 2.0
1955  * @see ucnv_setFallback
1956  */
1957 U_CAPI UBool U_EXPORT2
1958 ucnv_usesFallback(const UConverter *cnv);
1959 
1960 /**
1961  * Detects Unicode signature byte sequences at the start of the byte stream
1962  * and returns the charset name of the indicated Unicode charset.
1963  * NULL is returned when no Unicode signature is recognized.
1964  * The number of bytes in the signature is output as well.
1965  *
1966  * The caller can ucnv_open() a converter using the charset name.
1967  * The first code unit (UChar) from the start of the stream will be U+FEFF
1968  * (the Unicode BOM/signature character) and can usually be ignored.
1969  *
1970  * For most Unicode charsets it is also possible to ignore the indicated
1971  * number of initial stream bytes and start converting after them.
1972  * However, there are stateful Unicode charsets (UTF-7 and BOCU-1) for which
1973  * this will not work. Therefore, it is best to ignore the first output UChar
1974  * instead of the input signature bytes.
1975  * <p>
1976  * Usage:
1977  * \snippet samples/ucnv/convsamp.cpp ucnv_detectUnicodeSignature
1978  *
1979  * @param source            The source string in which the signature should be detected.
1980  * @param sourceLength      Length of the input string, or -1 if terminated with a NUL byte.
1981  * @param signatureLength   A pointer to int32_t to receive the number of bytes that make up the signature
1982  *                          of the detected UTF. 0 if not detected.
1983  *                          Can be a NULL pointer.
1984  * @param pErrorCode        ICU error code in/out parameter.
1985  *                          Must fulfill U_SUCCESS before the function call.
1986  * @return The name of the encoding detected. NULL if encoding is not detected.
1987  * @stable ICU 2.4
1988  */
1989 U_CAPI const char* U_EXPORT2
1990 ucnv_detectUnicodeSignature(const char* source,
1991                             int32_t sourceLength,
1992                             int32_t *signatureLength,
1993                             UErrorCode *pErrorCode);
1994 
1995 /**
1996  * Returns the number of UChars held in the converter's internal state
1997  * because more input is needed for completing the conversion. This function is
1998  * useful for mapping semantics of ICU's converter interface to those of iconv,
1999  * and this information is not needed for normal conversion.
2000  * @param cnv       The converter in which the input is held
2001  * @param status    ICU error code in/out parameter.
2002  *                  Must fulfill U_SUCCESS before the function call.
2003  * @return The number of UChars in the state. -1 if an error is encountered.
2004  * @stable ICU 3.4
2005  */
2006 U_CAPI int32_t U_EXPORT2
2007 ucnv_fromUCountPending(const UConverter* cnv, UErrorCode* status);
2008 
2009 /**
2010  * Returns the number of chars held in the converter's internal state
2011  * because more input is needed for completing the conversion. This function is
2012  * useful for mapping semantics of ICU's converter interface to those of iconv,
2013  * and this information is not needed for normal conversion.
2014  * @param cnv       The converter in which the input is held as internal state
2015  * @param status    ICU error code in/out parameter.
2016  *                  Must fulfill U_SUCCESS before the function call.
2017  * @return The number of chars in the state. -1 if an error is encountered.
2018  * @stable ICU 3.4
2019  */
2020 U_CAPI int32_t U_EXPORT2
2021 ucnv_toUCountPending(const UConverter* cnv, UErrorCode* status);
2022 
2023 /**
2024  * Returns whether or not the charset of the converter has a fixed number of bytes
2025  * per charset character.
2026  * An example of this are converters that are of the type UCNV_SBCS or UCNV_DBCS.
2027  * Another example is UTF-32 which is always 4 bytes per character.
2028  * A Unicode code point may be represented by more than one UTF-8 or UTF-16 code unit
2029  * but a UTF-32 converter encodes each code point with 4 bytes.
2030  * Note: This method is not intended to be used to determine whether the charset has a
2031  * fixed ratio of bytes to Unicode codes <i>units</i> for any particular Unicode encoding form.
2032  * false is returned with the UErrorCode if error occurs or cnv is NULL.
2033  * @param cnv       The converter to be tested
2034  * @param status    ICU error code in/out parameter
2035  * @return true if the converter is fixed-width
2036  * @stable ICU 4.8
2037  */
2038 U_CAPI UBool U_EXPORT2
2039 ucnv_isFixedWidth(UConverter *cnv, UErrorCode *status);
2040 
2041 #endif
2042 
2043 #endif
2044 /*_UCNV*/
2045