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