Home | History | Annotate | Download | only in unicode
      1 /*
      2 **********************************************************************
      3 *   Copyright (C) 1999-2010, International Business Machines
      4 *   Corporation and others.  All Rights Reserved.
      5 **********************************************************************
      6  *  ucnv.h:
      7  *  External APIs for the ICU's codeset conversion library
      8  *  Bertrand A. Damiba
      9  *
     10  * Modification History:
     11  *
     12  *   Date        Name        Description
     13  *   04/04/99    helena      Fixed internal header inclusion.
     14  *   05/11/00    helena      Added setFallback and usesFallback APIs.
     15  *   06/29/2000  helena      Major rewrite of the callback APIs.
     16  *   12/07/2000  srl         Update of documentation
     17  */
     18 
     19 /**
     20  * \file
     21  * \brief C API: Character conversion
     22  *
     23  * <h2>Character Conversion C API</h2>
     24  *
     25  * <p>This API is used to convert codepage or character encoded data to and
     26  * from UTF-16. You can open a converter with {@link ucnv_open() }. With that
     27  * converter, you can get its properties, set options, convert your data and
     28  * close the converter.</p>
     29  *
     30  * <p>Since many software programs recogize different converter names for
     31  * different types of converters, there are other functions in this API to
     32  * iterate over the converter aliases. The functions {@link ucnv_getAvailableName() },
     33  * {@link ucnv_getAlias() } and {@link ucnv_getStandardName() } are some of the
     34  * more frequently used alias functions to get this information.</p>
     35  *
     36  * <p>When a converter encounters an illegal, irregular, invalid or unmappable character
     37  * its default behavior is to use a substitution character to replace the
     38  * bad byte sequence. This behavior can be changed by using {@link ucnv_setFromUCallBack() }
     39  * or {@link ucnv_setToUCallBack() } on the converter. The header ucnv_err.h defines
     40  * many other callback actions that can be used instead of a character substitution.</p>
     41  *
     42  * <p>More information about this API can be found in our
     43  * <a href="http://icu-project.org/userguide/conversion.html">User's
     44  * Guide</a>.</p>
     45  */
     46 
     47 #ifndef UCNV_H
     48 #define UCNV_H
     49 
     50 #include "unicode/ucnv_err.h"
     51 #include "unicode/uenum.h"
     52 #include "unicode/localpointer.h"
     53 
     54 #ifndef __USET_H__
     55 
     56 /**
     57  * USet is the C API type for Unicode sets.
     58  * It is forward-declared here to avoid including the header file if related
     59  * conversion APIs are not used.
     60  * See unicode/uset.h
     61  *
     62  * @see ucnv_getUnicodeSet
     63  * @stable ICU 2.6
     64  */
     65 struct USet;
     66 /** @stable ICU 2.6 */
     67 typedef struct USet USet;
     68 
     69 #endif
     70 
     71 #if !UCONFIG_NO_CONVERSION
     72 
     73 U_CDECL_BEGIN
     74 
     75 /** Maximum length of a converter name including the terminating NULL @stable ICU 2.0 */
     76 #define UCNV_MAX_CONVERTER_NAME_LENGTH 60
     77 /** Maximum length of a converter name including path and terminating NULL @stable ICU 2.0 */
     78 #define UCNV_MAX_FULL_FILE_NAME_LENGTH (600+UCNV_MAX_CONVERTER_NAME_LENGTH)
     79 
     80 /** Shift in for EBDCDIC_STATEFUL and iso2022 states @stable ICU 2.0 */
     81 #define  UCNV_SI 0x0F
     82 /** Shift out for EBDCDIC_STATEFUL and iso2022 states @stable ICU 2.0 */
     83 #define  UCNV_SO 0x0E
     84 
     85 /**
     86  * Enum for specifying basic types of converters
     87  * @see ucnv_getType
     88  * @stable ICU 2.0
     89  */
     90 typedef enum {
     91     UCNV_UNSUPPORTED_CONVERTER = -1,
     92     UCNV_SBCS = 0,
     93     UCNV_DBCS = 1,
     94     UCNV_MBCS = 2,
     95     UCNV_LATIN_1 = 3,
     96     UCNV_UTF8 = 4,
     97     UCNV_UTF16_BigEndian = 5,
     98     UCNV_UTF16_LittleEndian = 6,
     99     UCNV_UTF32_BigEndian = 7,
    100     UCNV_UTF32_LittleEndian = 8,
    101     UCNV_EBCDIC_STATEFUL = 9,
    102     UCNV_ISO_2022 = 10,
    103 
    104     UCNV_LMBCS_1 = 11,
    105     UCNV_LMBCS_2,
    106     UCNV_LMBCS_3,
    107     UCNV_LMBCS_4,
    108     UCNV_LMBCS_5,
    109     UCNV_LMBCS_6,
    110     UCNV_LMBCS_8,
    111     UCNV_LMBCS_11,
    112     UCNV_LMBCS_16,
    113     UCNV_LMBCS_17,
    114     UCNV_LMBCS_18,
    115     UCNV_LMBCS_19,
    116     UCNV_LMBCS_LAST = UCNV_LMBCS_19,
    117     UCNV_HZ,
    118     UCNV_SCSU,
    119     UCNV_ISCII,
    120     UCNV_US_ASCII,
    121     UCNV_UTF7,
    122     UCNV_BOCU1,
    123     UCNV_UTF16,
    124     UCNV_UTF32,
    125     UCNV_CESU8,
    126     UCNV_IMAP_MAILBOX,
    127 
    128     /* Number of converter types for which we have conversion routines. */
    129     UCNV_NUMBER_OF_SUPPORTED_CONVERTER_TYPES
    130 
    131 } UConverterType;
    132 
    133 /**
    134  * Enum for specifying which platform a converter ID refers to.
    135  * The use of platform/CCSID is not recommended. See ucnv_openCCSID().
    136  *
    137  * @see ucnv_getPlatform
    138  * @see ucnv_openCCSID
    139  * @see ucnv_getCCSID
    140  * @stable ICU 2.0
    141  */
    142 typedef enum {
    143     UCNV_UNKNOWN = -1,
    144     UCNV_IBM = 0
    145 } UConverterPlatform;
    146 
    147 /**
    148  * Function pointer for error callback in the codepage to unicode direction.
    149  * Called when an error has occured in conversion to unicode, or on open/close of the callback (see reason).
    150  * @param context Pointer to the callback's private data
    151  * @param args Information about the conversion in progress
    152  * @param codeUnits Points to 'length' bytes of the concerned codepage sequence
    153  * @param length Size (in bytes) of the concerned codepage sequence
    154  * @param reason Defines the reason the callback was invoked
    155  * @param pErrorCode    ICU error code in/out parameter.
    156  *                      For converter callback functions, set to a conversion error
    157  *                      before the call, and the callback may reset it to U_ZERO_ERROR.
    158  * @see ucnv_setToUCallBack
    159  * @see UConverterToUnicodeArgs
    160  * @stable ICU 2.0
    161  */
    162 typedef void (U_EXPORT2 *UConverterToUCallback) (
    163                   const void* context,
    164                   UConverterToUnicodeArgs *args,
    165                   const char *codeUnits,
    166                   int32_t length,
    167                   UConverterCallbackReason reason,
    168                   UErrorCode *pErrorCode);
    169 
    170 /**
    171  * Function pointer for error callback in the unicode to codepage direction.
    172  * Called when an error has occured in conversion from unicode, or on open/close of the callback (see reason).
    173  * @param context Pointer to the callback's private data
    174  * @param args Information about the conversion in progress
    175  * @param codeUnits Points to 'length' UChars of the concerned Unicode sequence
    176  * @param length Size (in bytes) of the concerned codepage sequence
    177  * @param codePoint Single UChar32 (UTF-32) containing the concerend Unicode codepoint.
    178  * @param reason Defines the reason the callback was invoked
    179  * @param pErrorCode    ICU error code in/out parameter.
    180  *                      For converter callback functions, set to a conversion error
    181  *                      before the call, and the callback may reset it to U_ZERO_ERROR.
    182  * @see ucnv_setFromUCallBack
    183  * @stable ICU 2.0
    184  */
    185 typedef void (U_EXPORT2 *UConverterFromUCallback) (
    186                     const void* context,
    187                     UConverterFromUnicodeArgs *args,
    188                     const UChar* codeUnits,
    189                     int32_t length,
    190                     UChar32 codePoint,
    191                     UConverterCallbackReason reason,
    192                     UErrorCode *pErrorCode);
    193 
    194 U_CDECL_END
    195 
    196 /**
    197  * Character that separates converter names from options and options from each other.
    198  * @see ucnv_open
    199  * @stable ICU 2.0
    200  */
    201 #define UCNV_OPTION_SEP_CHAR ','
    202 
    203 /**
    204  * String version of UCNV_OPTION_SEP_CHAR.
    205  * @see ucnv_open
    206  * @stable ICU 2.0
    207  */
    208 #define UCNV_OPTION_SEP_STRING ","
    209 
    210 /**
    211  * Character that separates a converter option from its value.
    212  * @see ucnv_open
    213  * @stable ICU 2.0
    214  */
    215 #define UCNV_VALUE_SEP_CHAR '='
    216 
    217 /**
    218  * String version of UCNV_VALUE_SEP_CHAR.
    219  * @see ucnv_open
    220  * @stable ICU 2.0
    221  */
    222 #define UCNV_VALUE_SEP_STRING "="
    223 
    224 /**
    225  * Converter option for specifying a locale.
    226  * For example, ucnv_open("SCSU,locale=ja", &errorCode);
    227  * See convrtrs.txt.
    228  *
    229  * @see ucnv_open
    230  * @stable ICU 2.0
    231  */
    232 #define UCNV_LOCALE_OPTION_STRING ",locale="
    233 
    234 /**
    235  * Converter option for specifying a version selector (0..9) for some converters.
    236  * For example,
    237  * \code
    238  *   ucnv_open("UTF-7,version=1", &errorCode);
    239  * \endcode
    240  * See convrtrs.txt.
    241  *
    242  * @see ucnv_open
    243  * @stable ICU 2.4
    244  */
    245 #define UCNV_VERSION_OPTION_STRING ",version="
    246 
    247 /**
    248  * Converter option for EBCDIC SBCS or mixed-SBCS/DBCS (stateful) codepages.
    249  * Swaps Unicode mappings for EBCDIC LF and NL codes, as used on
    250  * S/390 (z/OS) Unix System Services (Open Edition).
    251  * For example, ucnv_open("ibm-1047,swaplfnl", &errorCode);
    252  * See convrtrs.txt.
    253  *
    254  * @see ucnv_open
    255  * @stable ICU 2.4
    256  */
    257 #define UCNV_SWAP_LFNL_OPTION_STRING ",swaplfnl"
    258 
    259 /**
    260  * Do a fuzzy compare of two converter/alias names.
    261  * The comparison is case-insensitive, ignores leading zeroes if they are not
    262  * followed by further digits, and ignores all but letters and digits.
    263  * Thus the strings "UTF-8", "utf_8", "u*T@f08" and "Utf 8" are exactly equivalent.
    264  * See section 1.4, Charset Alias Matching in Unicode Technical Standard #22
    265  * at http://www.unicode.org/reports/tr22/
    266  *
    267  * @param name1 a converter name or alias, zero-terminated
    268  * @param name2 a converter name or alias, zero-terminated
    269  * @return 0 if the names match, or a negative value if the name1
    270  * lexically precedes name2, or a positive value if the name1
    271  * lexically follows name2.
    272  * @stable ICU 2.0
    273  */
    274 U_STABLE int U_EXPORT2
    275 ucnv_compareNames(const char *name1, const char *name2);
    276 
    277 
    278 /**
    279  * Creates a UConverter object with the name of a coded character set specified as a C string.
    280  * The actual name will be resolved with the alias file
    281  * using a case-insensitive string comparison that ignores
    282  * leading zeroes and all non-alphanumeric characters.
    283  * E.g., the names "UTF8", "utf-8", "u*T@f08" and "Utf 8" are all equivalent.
    284  * (See also ucnv_compareNames().)
    285  * If <code>NULL</code> is passed for the converter name, it will create one with the
    286  * getDefaultName return value.
    287  *
    288  * <p>A converter name for ICU 1.5 and above may contain options
    289  * like a locale specification to control the specific behavior of
    290  * the newly instantiated converter.
    291  * The meaning of the options depends on the particular converter.
    292  * If an option is not defined for or recognized by a given converter, then it is ignored.</p>
    293  *
    294  * <p>Options are appended to the converter name string, with a
    295  * <code>UCNV_OPTION_SEP_CHAR</code> between the name and the first option and
    296  * also between adjacent options.</p>
    297  *
    298  * <p>If the alias is ambiguous, then the preferred converter is used
    299  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.</p>
    300  *
    301  * <p>The conversion behavior and names can vary between platforms. ICU may
    302  * convert some characters differently from other platforms. Details on this topic
    303  * are in the <a href="http://icu-project.org/userguide/conversion.html">User's
    304  * Guide</a>. Aliases starting with a "cp" prefix have no specific meaning
    305  * other than its an alias starting with the letters "cp". Please do not
    306  * associate any meaning to these aliases.</p>
    307  *
    308  * @param converterName Name of the coded character set table.
    309  *          This may have options appended to the string.
    310  *          IANA alias character set names, IBM CCSIDs starting with "ibm-",
    311  *          Windows codepage numbers starting with "windows-" are frequently
    312  *          used for this parameter. See ucnv_getAvailableName and
    313  *          ucnv_getAlias for a complete list that is available.
    314  *          If this parameter is NULL, the default converter will be used.
    315  * @param err outgoing error status <TT>U_MEMORY_ALLOCATION_ERROR, U_FILE_ACCESS_ERROR</TT>
    316  * @return the created Unicode converter object, or <TT>NULL</TT> if an error occured
    317  * @see ucnv_openU
    318  * @see ucnv_openCCSID
    319  * @see ucnv_getAvailableName
    320  * @see ucnv_getAlias
    321  * @see ucnv_getDefaultName
    322  * @see ucnv_close
    323  * @see ucnv_compareNames
    324  * @stable ICU 2.0
    325  */
    326 U_STABLE UConverter* U_EXPORT2
    327 ucnv_open(const char *converterName, UErrorCode *err);
    328 
    329 
    330 /**
    331  * Creates a Unicode converter with the names specified as unicode string.
    332  * The name should be limited to the ASCII-7 alphanumerics range.
    333  * The actual name will be resolved with the alias file
    334  * using a case-insensitive string comparison that ignores
    335  * leading zeroes and all non-alphanumeric characters.
    336  * E.g., the names "UTF8", "utf-8", "u*T@f08" and "Utf 8" are all equivalent.
    337  * (See also ucnv_compareNames().)
    338  * If <TT>NULL</TT> is passed for the converter name, it will create
    339  * one with the ucnv_getDefaultName() return value.
    340  * If the alias is ambiguous, then the preferred converter is used
    341  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
    342  *
    343  * <p>See ucnv_open for the complete details</p>
    344  * @param name Name of the UConverter table in a zero terminated
    345  *        Unicode string
    346  * @param err outgoing error status <TT>U_MEMORY_ALLOCATION_ERROR,
    347  *        U_FILE_ACCESS_ERROR</TT>
    348  * @return the created Unicode converter object, or <TT>NULL</TT> if an
    349  *        error occured
    350  * @see ucnv_open
    351  * @see ucnv_openCCSID
    352  * @see ucnv_close
    353  * @see ucnv_compareNames
    354  * @stable ICU 2.0
    355  */
    356 U_STABLE UConverter* U_EXPORT2
    357 ucnv_openU(const UChar *name,
    358            UErrorCode *err);
    359 
    360 /**
    361  * Creates a UConverter object from a CCSID number and platform pair.
    362  * Note that the usefulness of this function is limited to platforms with numeric
    363  * encoding IDs. Only IBM and Microsoft platforms use numeric (16-bit) identifiers for
    364  * encodings.
    365  *
    366  * In addition, IBM CCSIDs and Unicode conversion tables are not 1:1 related.
    367  * For many IBM CCSIDs there are multiple (up to six) Unicode conversion tables, and
    368  * for some Unicode conversion tables there are multiple CCSIDs.
    369  * Some "alternate" Unicode conversion tables are provided by the
    370  * IBM CDRA conversion table registry.
    371  * The most prominent example of a systematic modification of conversion tables that is
    372  * not provided in the form of conversion table files in the repository is
    373  * that S/390 Unix System Services swaps the codes for Line Feed and New Line in all
    374  * EBCDIC codepages, which requires such a swap in the Unicode conversion tables as well.
    375  *
    376  * Only IBM default conversion tables are accessible with ucnv_openCCSID().
    377  * ucnv_getCCSID() will return the same CCSID for all conversion tables that are associated
    378  * with that CCSID.
    379  *
    380  * Currently, the only "platform" supported in the ICU converter API is UCNV_IBM.
    381  *
    382  * In summary, the use of CCSIDs and the associated API functions is not recommended.
    383  *
    384  * In order to open a converter with the default IBM CDRA Unicode conversion table,
    385  * you can use this function or use the prefix "ibm-":
    386  * \code
    387  *     char name[20];
    388  *     sprintf(name, "ibm-%hu", ccsid);
    389  *     cnv=ucnv_open(name, &errorCode);
    390  * \endcode
    391  *
    392  * In order to open a converter with the IBM S/390 Unix System Services variant
    393  * of a Unicode/EBCDIC conversion table,
    394  * you can use the prefix "ibm-" together with the option string UCNV_SWAP_LFNL_OPTION_STRING:
    395  * \code
    396  *     char name[20];
    397  *     sprintf(name, "ibm-%hu" UCNV_SWAP_LFNL_OPTION_STRING, ccsid);
    398  *     cnv=ucnv_open(name, &errorCode);
    399  * \endcode
    400  *
    401  * In order to open a converter from a Microsoft codepage number, use the prefix "cp":
    402  * \code
    403  *     char name[20];
    404  *     sprintf(name, "cp%hu", codepageID);
    405  *     cnv=ucnv_open(name, &errorCode);
    406  * \endcode
    407  *
    408  * If the alias is ambiguous, then the preferred converter is used
    409  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
    410  *
    411  * @param codepage codepage number to create
    412  * @param platform the platform in which the codepage number exists
    413  * @param err error status <TT>U_MEMORY_ALLOCATION_ERROR, U_FILE_ACCESS_ERROR</TT>
    414  * @return the created Unicode converter object, or <TT>NULL</TT> if an error
    415  *   occured.
    416  * @see ucnv_open
    417  * @see ucnv_openU
    418  * @see ucnv_close
    419  * @see ucnv_getCCSID
    420  * @see ucnv_getPlatform
    421  * @see UConverterPlatform
    422  * @stable ICU 2.0
    423  */
    424 U_STABLE UConverter* U_EXPORT2
    425 ucnv_openCCSID(int32_t codepage,
    426                UConverterPlatform platform,
    427                UErrorCode * err);
    428 
    429 /**
    430  * <p>Creates a UConverter object specified from a packageName and a converterName.</p>
    431  *
    432  * <p>The packageName and converterName must point to an ICU udata object, as defined by
    433  *   <code> udata_open( packageName, "cnv", converterName, err) </code> or equivalent.
    434  * Typically, packageName will refer to a (.dat) file, or to a package registered with
    435  * udata_setAppData(). Using a full file or directory pathname for packageName is deprecated.</p>
    436  *
    437  * <p>The name will NOT be looked up in the alias mechanism, nor will the converter be
    438  * stored in the converter cache or the alias table. The only way to open further converters
    439  * is call this function multiple times, or use the ucnv_safeClone() function to clone a
    440  * 'master' converter.</p>
    441  *
    442  * <p>A future version of ICU may add alias table lookups and/or caching
    443  * to this function.</p>
    444  *
    445  * <p>Example Use:
    446  *      <code>cnv = ucnv_openPackage("myapp", "myconverter", &err);</code>
    447  * </p>
    448  *
    449  * @param packageName name of the package (equivalent to 'path' in udata_open() call)
    450  * @param converterName name of the data item to be used, without suffix.
    451  * @param err outgoing error status <TT>U_MEMORY_ALLOCATION_ERROR, U_FILE_ACCESS_ERROR</TT>
    452  * @return the created Unicode converter object, or <TT>NULL</TT> if an error occured
    453  * @see udata_open
    454  * @see ucnv_open
    455  * @see ucnv_safeClone
    456  * @see ucnv_close
    457  * @stable ICU 2.2
    458  */
    459 U_STABLE UConverter* U_EXPORT2
    460 ucnv_openPackage(const char *packageName, const char *converterName, UErrorCode *err);
    461 
    462 /**
    463  * Thread safe converter cloning operation.
    464  * For most efficient operation, pass in a stackBuffer (and a *pBufferSize)
    465  * with at least U_CNV_SAFECLONE_BUFFERSIZE bytes of space.
    466  * If the buffer size is sufficient, then the clone will use the stack buffer;
    467  * otherwise, it will be allocated, and *pBufferSize will indicate
    468  * the actual size. (This should not occur with U_CNV_SAFECLONE_BUFFERSIZE.)
    469  *
    470  * You must ucnv_close() the clone in any case.
    471  *
    472  * If *pBufferSize==0, (regardless of whether stackBuffer==NULL or not)
    473  * then *pBufferSize will be changed to a sufficient size
    474  * for cloning this converter,
    475  * without actually cloning the converter ("pure pre-flighting").
    476  *
    477  * If *pBufferSize is greater than zero but not large enough for a stack-based
    478  * clone, then the converter is cloned using newly allocated memory
    479  * and *pBufferSize is changed to the necessary size.
    480  *
    481  * If the converter clone fits into the stack buffer but the stack buffer is not
    482  * sufficiently aligned for the clone, then the clone will use an
    483  * adjusted pointer and use an accordingly smaller buffer size.
    484  *
    485  * @param cnv converter to be cloned
    486  * @param stackBuffer user allocated space for the new clone. If NULL new memory will be allocated.
    487  *  If buffer is not large enough, new memory will be allocated.
    488  *  Clients can use the U_CNV_SAFECLONE_BUFFERSIZE. This will probably be enough to avoid memory allocations.
    489  * @param pBufferSize pointer to size of allocated space. pBufferSize must not be NULL.
    490  * @param status to indicate whether the operation went on smoothly or there were errors
    491  *  An informational status value, U_SAFECLONE_ALLOCATED_WARNING,
    492  *  is used if any allocations were necessary.
    493  *  However, it is better to check if *pBufferSize grew for checking for
    494  *  allocations because warning codes can be overridden by subsequent
    495  *  function calls.
    496  * @return pointer to the new clone
    497  * @stable ICU 2.0
    498  */
    499 U_STABLE UConverter * U_EXPORT2
    500 ucnv_safeClone(const UConverter *cnv,
    501                void             *stackBuffer,
    502                int32_t          *pBufferSize,
    503                UErrorCode       *status);
    504 
    505 /**
    506  * \def U_CNV_SAFECLONE_BUFFERSIZE
    507  * Definition of a buffer size that is designed to be large enough for
    508  * converters to be cloned with ucnv_safeClone().
    509  * @stable ICU 2.0
    510  */
    511 #define U_CNV_SAFECLONE_BUFFERSIZE  1024
    512 
    513 /**
    514  * Deletes the unicode converter and releases resources associated
    515  * with just this instance.
    516  * Does not free up shared converter tables.
    517  *
    518  * @param converter the converter object to be deleted
    519  * @see ucnv_open
    520  * @see ucnv_openU
    521  * @see ucnv_openCCSID
    522  * @stable ICU 2.0
    523  */
    524 U_STABLE void  U_EXPORT2
    525 ucnv_close(UConverter * converter);
    526 
    527 #if U_SHOW_CPLUSPLUS_API
    528 
    529 U_NAMESPACE_BEGIN
    530 
    531 /**
    532  * \class LocalUConverterPointer
    533  * "Smart pointer" class, closes a UConverter via ucnv_close().
    534  * For most methods see the LocalPointerBase base class.
    535  *
    536  * @see LocalPointerBase
    537  * @see LocalPointer
    538  * @stable ICU 4.4
    539  */
    540 U_DEFINE_LOCAL_OPEN_POINTER(LocalUConverterPointer, UConverter, ucnv_close);
    541 
    542 U_NAMESPACE_END
    543 
    544 #endif
    545 
    546 /**
    547  * Fills in the output parameter, subChars, with the substitution characters
    548  * as multiple bytes.
    549  * If ucnv_setSubstString() set a Unicode string because the converter is
    550  * stateful, then subChars will be an empty string.
    551  *
    552  * @param converter the Unicode converter
    553  * @param subChars the subsitution characters
    554  * @param len on input the capacity of subChars, on output the number
    555  * of bytes copied to it
    556  * @param  err the outgoing error status code.
    557  * If the substitution character array is too small, an
    558  * <TT>U_INDEX_OUTOFBOUNDS_ERROR</TT> will be returned.
    559  * @see ucnv_setSubstString
    560  * @see ucnv_setSubstChars
    561  * @stable ICU 2.0
    562  */
    563 U_STABLE void U_EXPORT2
    564 ucnv_getSubstChars(const UConverter *converter,
    565                    char *subChars,
    566                    int8_t *len,
    567                    UErrorCode *err);
    568 
    569 /**
    570  * Sets the substitution chars when converting from unicode to a codepage. The
    571  * substitution is specified as a string of 1-4 bytes, and may contain
    572  * <TT>NULL</TT> bytes.
    573  * The subChars must represent a single character. The caller needs to know the
    574  * byte sequence of a valid character in the converter's charset.
    575  * For some converters, for example some ISO 2022 variants, only single-byte
    576  * substitution characters may be supported.
    577  * The newer ucnv_setSubstString() function relaxes these limitations.
    578  *
    579  * @param converter the Unicode converter
    580  * @param subChars the substitution character byte sequence we want set
    581  * @param len the number of bytes in subChars
    582  * @param err the error status code.  <TT>U_INDEX_OUTOFBOUNDS_ERROR </TT> if
    583  * len is bigger than the maximum number of bytes allowed in subchars
    584  * @see ucnv_setSubstString
    585  * @see ucnv_getSubstChars
    586  * @stable ICU 2.0
    587  */
    588 U_STABLE void U_EXPORT2
    589 ucnv_setSubstChars(UConverter *converter,
    590                    const char *subChars,
    591                    int8_t len,
    592                    UErrorCode *err);
    593 
    594 /**
    595  * Set a substitution string for converting from Unicode to a charset.
    596  * The caller need not know the charset byte sequence for each charset.
    597  *
    598  * Unlike ucnv_setSubstChars() which is designed to set a charset byte sequence
    599  * for a single character, this function takes a Unicode string with
    600  * zero, one or more characters, and immediately verifies that the string can be
    601  * converted to the charset.
    602  * If not, or if the result is too long (more than 32 bytes as of ICU 3.6),
    603  * then the function returns with an error accordingly.
    604  *
    605  * Also unlike ucnv_setSubstChars(), this function works for stateful charsets
    606  * by converting on the fly at the point of substitution rather than setting
    607  * a fixed byte sequence.
    608  *
    609  * @param cnv The UConverter object.
    610  * @param s The Unicode string.
    611  * @param length The number of UChars in s, or -1 for a NUL-terminated string.
    612  * @param err Pointer to a standard ICU error code. Its input value must
    613  *            pass the U_SUCCESS() test, or else the function returns
    614  *            immediately. Check for U_FAILURE() on output or use with
    615  *            function chaining. (See User Guide for details.)
    616  *
    617  * @see ucnv_setSubstChars
    618  * @see ucnv_getSubstChars
    619  * @stable ICU 3.6
    620  */
    621 U_STABLE void U_EXPORT2
    622 ucnv_setSubstString(UConverter *cnv,
    623                     const UChar *s,
    624                     int32_t length,
    625                     UErrorCode *err);
    626 
    627 /**
    628  * Fills in the output parameter, errBytes, with the error characters from the
    629  * last failing conversion.
    630  *
    631  * @param converter the Unicode converter
    632  * @param errBytes the codepage bytes which were in error
    633  * @param len on input the capacity of errBytes, on output the number of
    634  *  bytes which were copied to it
    635  * @param err the error status code.
    636  * If the substitution character array is too small, an
    637  * <TT>U_INDEX_OUTOFBOUNDS_ERROR</TT> will be returned.
    638  * @stable ICU 2.0
    639  */
    640 U_STABLE void U_EXPORT2
    641 ucnv_getInvalidChars(const UConverter *converter,
    642                      char *errBytes,
    643                      int8_t *len,
    644                      UErrorCode *err);
    645 
    646 /**
    647  * Fills in the output parameter, errChars, with the error characters from the
    648  * last failing conversion.
    649  *
    650  * @param converter the Unicode converter
    651  * @param errUChars the UChars which were in error
    652  * @param len on input the capacity of errUChars, on output the number of
    653  *  UChars which were copied to it
    654  * @param err the error status code.
    655  * If the substitution character array is too small, an
    656  * <TT>U_INDEX_OUTOFBOUNDS_ERROR</TT> will be returned.
    657  * @stable ICU 2.0
    658  */
    659 U_STABLE void U_EXPORT2
    660 ucnv_getInvalidUChars(const UConverter *converter,
    661                       UChar *errUChars,
    662                       int8_t *len,
    663                       UErrorCode *err);
    664 
    665 /**
    666  * Resets the state of a converter to the default state. This is used
    667  * in the case of an error, to restart a conversion from a known default state.
    668  * It will also empty the internal output buffers.
    669  * @param converter the Unicode converter
    670  * @stable ICU 2.0
    671  */
    672 U_STABLE void U_EXPORT2
    673 ucnv_reset(UConverter *converter);
    674 
    675 /**
    676  * Resets the to-Unicode part of a converter state to the default state.
    677  * This is used in the case of an error to restart a conversion to
    678  * Unicode to a known default state. It will also empty the internal
    679  * output buffers used for the conversion to Unicode codepoints.
    680  * @param converter the Unicode converter
    681  * @stable ICU 2.0
    682  */
    683 U_STABLE void U_EXPORT2
    684 ucnv_resetToUnicode(UConverter *converter);
    685 
    686 /**
    687  * Resets the from-Unicode part of a converter state to the default state.
    688  * This is used in the case of an error to restart a conversion from
    689  * Unicode to a known default state. It will also empty the internal output
    690  * buffers used for the conversion from Unicode codepoints.
    691  * @param converter the Unicode converter
    692  * @stable ICU 2.0
    693  */
    694 U_STABLE void U_EXPORT2
    695 ucnv_resetFromUnicode(UConverter *converter);
    696 
    697 /**
    698  * Returns the maximum number of bytes that are output per UChar in conversion
    699  * from Unicode using this converter.
    700  * The returned number can be used with UCNV_GET_MAX_BYTES_FOR_STRING
    701  * to calculate the size of a target buffer for conversion from Unicode.
    702  *
    703  * Note: Before ICU 2.8, this function did not return reliable numbers for
    704  * some stateful converters (EBCDIC_STATEFUL, ISO-2022) and LMBCS.
    705  *
    706  * This number may not be the same as the maximum number of bytes per
    707  * "conversion unit". In other words, it may not be the intuitively expected
    708  * number of bytes per character that would be published for a charset,
    709  * and may not fulfill any other purpose than the allocation of an output
    710  * buffer of guaranteed sufficient size for a given input length and converter.
    711  *
    712  * Examples for special cases that are taken into account:
    713  * - Supplementary code points may convert to more bytes than BMP code points.
    714  *   This function returns bytes per UChar (UTF-16 code unit), not per
    715  *   Unicode code point, for efficient buffer allocation.
    716  * - State-shifting output (SI/SO, escapes, etc.) from stateful converters.
    717  * - When m input UChars are converted to n output bytes, then the maximum m/n
    718  *   is taken into account.
    719  *
    720  * The number returned here does not take into account
    721  * (see UCNV_GET_MAX_BYTES_FOR_STRING):
    722  * - callbacks which output more than one charset character sequence per call,
    723  *   like escape callbacks
    724  * - initial and final non-character bytes that are output by some converters
    725  *   (automatic BOMs, initial escape sequence, final SI, etc.)
    726  *
    727  * Examples for returned values:
    728  * - SBCS charsets: 1
    729  * - Shift-JIS: 2
    730  * - UTF-16: 2 (2 per BMP, 4 per surrogate _pair_, BOM not counted)
    731  * - UTF-8: 3 (3 per BMP, 4 per surrogate _pair_)
    732  * - EBCDIC_STATEFUL (EBCDIC mixed SBCS/DBCS): 3 (SO + DBCS)
    733  * - ISO-2022: 3 (always outputs UTF-8)
    734  * - ISO-2022-JP: 6 (4-byte escape sequences + DBCS)
    735  * - ISO-2022-CN: 8 (4-byte designator sequences + 2-byte SS2/SS3 + DBCS)
    736  *
    737  * @param converter The Unicode converter.
    738  * @return The maximum number of bytes per UChar that are output by ucnv_fromUnicode(),
    739  *         to be used together with UCNV_GET_MAX_BYTES_FOR_STRING for buffer allocation.
    740  *
    741  * @see UCNV_GET_MAX_BYTES_FOR_STRING
    742  * @see ucnv_getMinCharSize
    743  * @stable ICU 2.0
    744  */
    745 U_STABLE int8_t U_EXPORT2
    746 ucnv_getMaxCharSize(const UConverter *converter);
    747 
    748 /**
    749  * Calculates the size of a buffer for conversion from Unicode to a charset.
    750  * The calculated size is guaranteed to be sufficient for this conversion.
    751  *
    752  * It takes into account initial and final non-character bytes that are output
    753  * by some converters.
    754  * It does not take into account callbacks which output more than one charset
    755  * character sequence per call, like escape callbacks.
    756  * The default (substitution) callback only outputs one charset character sequence.
    757  *
    758  * @param length Number of UChars to be converted.
    759  * @param maxCharSize Return value from ucnv_getMaxCharSize() for the converter
    760  *                    that will be used.
    761  * @return Size of a buffer that will be large enough to hold the output bytes of
    762  *         converting length UChars with the converter that returned the maxCharSize.
    763  *
    764  * @see ucnv_getMaxCharSize
    765  * @stable ICU 2.8
    766  */
    767 #define UCNV_GET_MAX_BYTES_FOR_STRING(length, maxCharSize) \
    768      (((int32_t)(length)+10)*(int32_t)(maxCharSize))
    769 
    770 /**
    771  * Returns the minimum byte length for characters in this codepage.
    772  * This is usually either 1 or 2.
    773  * @param converter the Unicode converter
    774  * @return the minimum number of bytes allowed by this particular converter
    775  * @see ucnv_getMaxCharSize
    776  * @stable ICU 2.0
    777  */
    778 U_STABLE int8_t U_EXPORT2
    779 ucnv_getMinCharSize(const UConverter *converter);
    780 
    781 /**
    782  * Returns the display name of the converter passed in based on the Locale
    783  * passed in. If the locale contains no display name, the internal ASCII
    784  * name will be filled in.
    785  *
    786  * @param converter the Unicode converter.
    787  * @param displayLocale is the specific Locale we want to localised for
    788  * @param displayName user provided buffer to be filled in
    789  * @param displayNameCapacity size of displayName Buffer
    790  * @param err error status code
    791  * @return displayNameLength number of UChar needed in displayName
    792  * @see ucnv_getName
    793  * @stable ICU 2.0
    794  */
    795 U_STABLE int32_t U_EXPORT2
    796 ucnv_getDisplayName(const UConverter *converter,
    797                     const char *displayLocale,
    798                     UChar *displayName,
    799                     int32_t displayNameCapacity,
    800                     UErrorCode *err);
    801 
    802 /**
    803  * Gets the internal, canonical name of the converter (zero-terminated).
    804  * The lifetime of the returned string will be that of the converter
    805  * passed to this function.
    806  * @param converter the Unicode converter
    807  * @param err UErrorCode status
    808  * @return the internal name of the converter
    809  * @see ucnv_getDisplayName
    810  * @stable ICU 2.0
    811  */
    812 U_STABLE const char * U_EXPORT2
    813 ucnv_getName(const UConverter *converter, UErrorCode *err);
    814 
    815 /**
    816  * Gets a codepage number associated with the converter. This is not guaranteed
    817  * to be the one used to create the converter. Some converters do not represent
    818  * platform registered codepages and return zero for the codepage number.
    819  * The error code fill-in parameter indicates if the codepage number
    820  * is available.
    821  * Does not check if the converter is <TT>NULL</TT> or if converter's data
    822  * table is <TT>NULL</TT>.
    823  *
    824  * Important: The use of CCSIDs is not recommended because it is limited
    825  * to only two platforms in principle and only one (UCNV_IBM) in the current
    826  * ICU converter API.
    827  * Also, CCSIDs are insufficient to identify IBM Unicode conversion tables precisely.
    828  * For more details see ucnv_openCCSID().
    829  *
    830  * @param converter the Unicode converter
    831  * @param err the error status code.
    832  * @return If any error occurrs, -1 will be returned otherwise, the codepage number
    833  * will be returned
    834  * @see ucnv_openCCSID
    835  * @see ucnv_getPlatform
    836  * @stable ICU 2.0
    837  */
    838 U_STABLE int32_t U_EXPORT2
    839 ucnv_getCCSID(const UConverter *converter,
    840               UErrorCode *err);
    841 
    842 /**
    843  * Gets a codepage platform associated with the converter. Currently,
    844  * only <TT>UCNV_IBM</TT> will be returned.
    845  * Does not test if the converter is <TT>NULL</TT> or if converter's data
    846  * table is <TT>NULL</TT>.
    847  * @param converter the Unicode converter
    848  * @param err the error status code.
    849  * @return The codepage platform
    850  * @stable ICU 2.0
    851  */
    852 U_STABLE UConverterPlatform U_EXPORT2
    853 ucnv_getPlatform(const UConverter *converter,
    854                  UErrorCode *err);
    855 
    856 /**
    857  * Gets the type of the converter
    858  * e.g. SBCS, MBCS, DBCS, UTF8, UTF16_BE, UTF16_LE, ISO_2022,
    859  * EBCDIC_STATEFUL, LATIN_1
    860  * @param converter a valid, opened converter
    861  * @return the type of the converter
    862  * @stable ICU 2.0
    863  */
    864 U_STABLE UConverterType U_EXPORT2
    865 ucnv_getType(const UConverter * converter);
    866 
    867 /**
    868  * Gets the "starter" (lead) bytes for converters of type MBCS.
    869  * Will fill in an <TT>U_ILLEGAL_ARGUMENT_ERROR</TT> if converter passed in
    870  * is not MBCS. Fills in an array of type UBool, with the value of the byte
    871  * as offset to the array. For example, if (starters[0x20] == TRUE) at return,
    872  * it means that the byte 0x20 is a starter byte in this converter.
    873  * Context pointers are always owned by the caller.
    874  *
    875  * @param converter a valid, opened converter of type MBCS
    876  * @param starters an array of size 256 to be filled in
    877  * @param err error status, <TT>U_ILLEGAL_ARGUMENT_ERROR</TT> if the
    878  * converter is not a type which can return starters.
    879  * @see ucnv_getType
    880  * @stable ICU 2.0
    881  */
    882 U_STABLE void U_EXPORT2
    883 ucnv_getStarters(const UConverter* converter,
    884                  UBool starters[256],
    885                  UErrorCode* err);
    886 
    887 
    888 /**
    889  * Selectors for Unicode sets that can be returned by ucnv_getUnicodeSet().
    890  * @see ucnv_getUnicodeSet
    891  * @stable ICU 2.6
    892  */
    893 typedef enum UConverterUnicodeSet {
    894     /** Select the set of roundtrippable Unicode code points. @stable ICU 2.6 */
    895     UCNV_ROUNDTRIP_SET,
    896     /** Select the set of Unicode code points with roundtrip or fallback mappings. @stable ICU 4.0 */
    897     UCNV_ROUNDTRIP_AND_FALLBACK_SET,
    898     /** Number of UConverterUnicodeSet selectors. @stable ICU 2.6 */
    899     UCNV_SET_COUNT
    900 } UConverterUnicodeSet;
    901 
    902 
    903 /**
    904  * Returns the set of Unicode code points that can be converted by an ICU converter.
    905  *
    906  * Returns one of several kinds of set:
    907  *
    908  * 1. UCNV_ROUNDTRIP_SET
    909  *
    910  * The set of all Unicode code points that can be roundtrip-converted
    911  * (converted without any data loss) with the converter (ucnv_fromUnicode()).
    912  * This set will not include code points that have fallback mappings
    913  * or are only the result of reverse fallback mappings.
    914  * This set will also not include PUA code points with fallbacks, although
    915  * ucnv_fromUnicode() will always uses those mappings despite ucnv_setFallback().
    916  * See UTR #22 "Character Mapping Markup Language"
    917  * at http://www.unicode.org/reports/tr22/
    918  *
    919  * This is useful for example for
    920  * - checking that a string or document can be roundtrip-converted with a converter,
    921  *   without/before actually performing the conversion
    922  * - testing if a converter can be used for text for typical text for a certain locale,
    923  *   by comparing its roundtrip set with the set of ExemplarCharacters from
    924  *   ICU's locale data or other sources
    925  *
    926  * 2. UCNV_ROUNDTRIP_AND_FALLBACK_SET
    927  *
    928  * The set of all Unicode code points that can be converted with the converter (ucnv_fromUnicode())
    929  * when fallbacks are turned on (see ucnv_setFallback()).
    930  * This set includes all code points with roundtrips and fallbacks (but not reverse fallbacks).
    931  *
    932  * In the future, there may be more UConverterUnicodeSet choices to select
    933  * sets with different properties.
    934  *
    935  * @param cnv The converter for which a set is requested.
    936  * @param setFillIn A valid USet *. It will be cleared by this function before
    937  *            the converter's specific set is filled into the USet.
    938  * @param whichSet A UConverterUnicodeSet selector;
    939  *              currently UCNV_ROUNDTRIP_SET is the only supported value.
    940  * @param pErrorCode ICU error code in/out parameter.
    941  *                   Must fulfill U_SUCCESS before the function call.
    942  *
    943  * @see UConverterUnicodeSet
    944  * @see uset_open
    945  * @see uset_close
    946  * @stable ICU 2.6
    947  */
    948 U_STABLE void U_EXPORT2
    949 ucnv_getUnicodeSet(const UConverter *cnv,
    950                    USet *setFillIn,
    951                    UConverterUnicodeSet whichSet,
    952                    UErrorCode *pErrorCode);
    953 
    954 /**
    955  * Gets the current calback function used by the converter when an illegal
    956  *  or invalid codepage sequence is found.
    957  * Context pointers are always owned by the caller.
    958  *
    959  * @param converter the unicode converter
    960  * @param action fillin: returns the callback function pointer
    961  * @param context fillin: returns the callback's private void* context
    962  * @see ucnv_setToUCallBack
    963  * @stable ICU 2.0
    964  */
    965 U_STABLE void U_EXPORT2
    966 ucnv_getToUCallBack (const UConverter * converter,
    967                      UConverterToUCallback *action,
    968                      const void **context);
    969 
    970 /**
    971  * Gets the current callback function used by the converter when illegal
    972  * or invalid Unicode sequence is found.
    973  * Context pointers are always owned by the caller.
    974  *
    975  * @param converter the unicode converter
    976  * @param action fillin: returns the callback function pointer
    977  * @param context fillin: returns the callback's private void* context
    978  * @see ucnv_setFromUCallBack
    979  * @stable ICU 2.0
    980  */
    981 U_STABLE void U_EXPORT2
    982 ucnv_getFromUCallBack (const UConverter * converter,
    983                        UConverterFromUCallback *action,
    984                        const void **context);
    985 
    986 /**
    987  * Changes the callback function used by the converter when
    988  * an illegal or invalid sequence is found.
    989  * Context pointers are always owned by the caller.
    990  * Predefined actions and contexts can be found in the ucnv_err.h header.
    991  *
    992  * @param converter the unicode converter
    993  * @param newAction the new callback function
    994  * @param newContext the new toUnicode callback context pointer. This can be NULL.
    995  * @param oldAction fillin: returns the old callback function pointer. This can be NULL.
    996  * @param oldContext fillin: returns the old callback's private void* context. This can be NULL.
    997  * @param err The error code status
    998  * @see ucnv_getToUCallBack
    999  * @stable ICU 2.0
   1000  */
   1001 U_STABLE void U_EXPORT2
   1002 ucnv_setToUCallBack (UConverter * converter,
   1003                      UConverterToUCallback newAction,
   1004                      const void* newContext,
   1005                      UConverterToUCallback *oldAction,
   1006                      const void** oldContext,
   1007                      UErrorCode * err);
   1008 
   1009 /**
   1010  * Changes the current callback function used by the converter when
   1011  * an illegal or invalid sequence is found.
   1012  * Context pointers are always owned by the caller.
   1013  * Predefined actions and contexts can be found in the ucnv_err.h header.
   1014  *
   1015  * @param converter the unicode converter
   1016  * @param newAction the new callback function
   1017  * @param newContext the new fromUnicode callback context pointer. This can be NULL.
   1018  * @param oldAction fillin: returns the old callback function pointer. This can be NULL.
   1019  * @param oldContext fillin: returns the old callback's private void* context. This can be NULL.
   1020  * @param err The error code status
   1021  * @see ucnv_getFromUCallBack
   1022  * @stable ICU 2.0
   1023  */
   1024 U_STABLE void U_EXPORT2
   1025 ucnv_setFromUCallBack (UConverter * converter,
   1026                        UConverterFromUCallback newAction,
   1027                        const void *newContext,
   1028                        UConverterFromUCallback *oldAction,
   1029                        const void **oldContext,
   1030                        UErrorCode * err);
   1031 
   1032 /**
   1033  * Converts an array of unicode characters to an array of codepage
   1034  * characters. This function is optimized for converting a continuous
   1035  * stream of data in buffer-sized chunks, where the entire source and
   1036  * target does not fit in available buffers.
   1037  *
   1038  * The source pointer is an in/out parameter. It starts out pointing where the
   1039  * conversion is to begin, and ends up pointing after the last UChar consumed.
   1040  *
   1041  * Target similarly starts out pointer at the first available byte in the output
   1042  * buffer, and ends up pointing after the last byte written to the output.
   1043  *
   1044  * The converter always attempts to consume the entire source buffer, unless
   1045  * (1.) the target buffer is full, or (2.) a failing error is returned from the
   1046  * current callback function.  When a successful error status has been
   1047  * returned, it means that all of the source buffer has been
   1048  *  consumed. At that point, the caller should reset the source and
   1049  *  sourceLimit pointers to point to the next chunk.
   1050  *
   1051  * At the end of the stream (flush==TRUE), the input is completely consumed
   1052  * when *source==sourceLimit and no error code is set.
   1053  * The converter object is then automatically reset by this function.
   1054  * (This means that a converter need not be reset explicitly between data
   1055  * streams if it finishes the previous stream without errors.)
   1056  *
   1057  * This is a <I>stateful</I> conversion. Additionally, even when all source data has
   1058  * been consumed, some data may be in the converters' internal state.
   1059  * Call this function repeatedly, updating the target pointers with
   1060  * the next empty chunk of target in case of a
   1061  * <TT>U_BUFFER_OVERFLOW_ERROR</TT>, and updating the source  pointers
   1062  *  with the next chunk of source when a successful error status is
   1063  * returned, until there are no more chunks of source data.
   1064  * @param converter the Unicode converter
   1065  * @param target I/O parameter. Input : Points to the beginning of the buffer to copy
   1066  *  codepage characters to. Output : points to after the last codepage character copied
   1067  *  to <TT>target</TT>.
   1068  * @param targetLimit the pointer just after last of the <TT>target</TT> buffer
   1069  * @param source I/O parameter, pointer to pointer to the source Unicode character buffer.
   1070  * @param sourceLimit the pointer just after the last of the source buffer
   1071  * @param offsets if NULL is passed, nothing will happen to it, otherwise it needs to have the same number
   1072  * of allocated cells as <TT>target</TT>. Will fill in offsets from target to source pointer
   1073  * 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>
   1074  * For output data carried across calls, and other data without a specific source character
   1075  * (such as from escape sequences or callbacks)  -1 will be placed for offsets.
   1076  * @param flush set to <TT>TRUE</TT> if the current source buffer is the last available
   1077  * chunk of the source, <TT>FALSE</TT> otherwise. Note that if a failing status is returned,
   1078  * this function may have to be called multiple times with flush set to <TT>TRUE</TT> until
   1079  * the source buffer is consumed.
   1080  * @param err the error status.  <TT>U_ILLEGAL_ARGUMENT_ERROR</TT> will be set if the
   1081  * converter is <TT>NULL</TT>.
   1082  * <code>U_BUFFER_OVERFLOW_ERROR</code> will be set if the target is full and there is
   1083  * still data to be written to the target.
   1084  * @see ucnv_fromUChars
   1085  * @see ucnv_convert
   1086  * @see ucnv_getMinCharSize
   1087  * @see ucnv_setToUCallBack
   1088  * @stable ICU 2.0
   1089  */
   1090 U_STABLE void U_EXPORT2
   1091 ucnv_fromUnicode (UConverter * converter,
   1092                   char **target,
   1093                   const char *targetLimit,
   1094                   const UChar ** source,
   1095                   const UChar * sourceLimit,
   1096                   int32_t* offsets,
   1097                   UBool flush,
   1098                   UErrorCode * err);
   1099 
   1100 /**
   1101  * Converts a buffer of codepage bytes into an array of unicode UChars
   1102  * characters. This function is optimized for converting a continuous
   1103  * stream of data in buffer-sized chunks, where the entire source and
   1104  * target does not fit in available buffers.
   1105  *
   1106  * The source pointer is an in/out parameter. It starts out pointing where the
   1107  * conversion is to begin, and ends up pointing after the last byte of source consumed.
   1108  *
   1109  * Target similarly starts out pointer at the first available UChar in the output
   1110  * buffer, and ends up pointing after the last UChar written to the output.
   1111  * It does NOT necessarily keep UChar sequences together.
   1112  *
   1113  * The converter always attempts to consume the entire source buffer, unless
   1114  * (1.) the target buffer is full, or (2.) a failing error is returned from the
   1115  * current callback function.  When a successful error status has been
   1116  * returned, it means that all of the source buffer has been
   1117  *  consumed. At that point, the caller should reset the source and
   1118  *  sourceLimit pointers to point to the next chunk.
   1119  *
   1120  * At the end of the stream (flush==TRUE), the input is completely consumed
   1121  * when *source==sourceLimit and no error code is set
   1122  * The converter object is then automatically reset by this function.
   1123  * (This means that a converter need not be reset explicitly between data
   1124  * streams if it finishes the previous stream without errors.)
   1125  *
   1126  * This is a <I>stateful</I> conversion. Additionally, even when all source data has
   1127  * been consumed, some data may be in the converters' internal state.
   1128  * Call this function repeatedly, updating the target pointers with
   1129  * the next empty chunk of target in case of a
   1130  * <TT>U_BUFFER_OVERFLOW_ERROR</TT>, and updating the source  pointers
   1131  *  with the next chunk of source when a successful error status is
   1132  * returned, until there are no more chunks of source data.
   1133  * @param converter the Unicode converter
   1134  * @param target I/O parameter. Input : Points to the beginning of the buffer to copy
   1135  *  UChars into. Output : points to after the last UChar copied.
   1136  * @param targetLimit the pointer just after the end of the <TT>target</TT> buffer
   1137  * @param source I/O parameter, pointer to pointer to the source codepage buffer.
   1138  * @param sourceLimit the pointer to the byte after the end of the source buffer
   1139  * @param offsets if NULL is passed, nothing will happen to it, otherwise it needs to have the same number
   1140  * of allocated cells as <TT>target</TT>. Will fill in offsets from target to source pointer
   1141  * 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>
   1142  * For output data carried across calls, and other data without a specific source character
   1143  * (such as from escape sequences or callbacks)  -1 will be placed for offsets.
   1144  * @param flush set to <TT>TRUE</TT> if the current source buffer is the last available
   1145  * chunk of the source, <TT>FALSE</TT> otherwise. Note that if a failing status is returned,
   1146  * this function may have to be called multiple times with flush set to <TT>TRUE</TT> until
   1147  * the source buffer is consumed.
   1148  * @param err the error status.  <TT>U_ILLEGAL_ARGUMENT_ERROR</TT> will be set if the
   1149  * converter is <TT>NULL</TT>.
   1150  * <code>U_BUFFER_OVERFLOW_ERROR</code> will be set if the target is full and there is
   1151  * still data to be written to the target.
   1152  * @see ucnv_fromUChars
   1153  * @see ucnv_convert
   1154  * @see ucnv_getMinCharSize
   1155  * @see ucnv_setFromUCallBack
   1156  * @see ucnv_getNextUChar
   1157  * @stable ICU 2.0
   1158  */
   1159 U_STABLE void U_EXPORT2
   1160 ucnv_toUnicode(UConverter *converter,
   1161                UChar **target,
   1162                const UChar *targetLimit,
   1163                const char **source,
   1164                const char *sourceLimit,
   1165                int32_t *offsets,
   1166                UBool flush,
   1167                UErrorCode *err);
   1168 
   1169 /**
   1170  * Convert the Unicode string into a codepage string using an existing UConverter.
   1171  * The output string is NUL-terminated if possible.
   1172  *
   1173  * This function is a more convenient but less powerful version of ucnv_fromUnicode().
   1174  * It is only useful for whole strings, not for streaming conversion.
   1175  *
   1176  * The maximum output buffer capacity required (barring output from callbacks) will be
   1177  * UCNV_GET_MAX_BYTES_FOR_STRING(srcLength, ucnv_getMaxCharSize(cnv)).
   1178  *
   1179  * @param cnv the converter object to be used (ucnv_resetFromUnicode() will be called)
   1180  * @param src the input Unicode string
   1181  * @param srcLength the input string length, or -1 if NUL-terminated
   1182  * @param dest destination string buffer, can be NULL if destCapacity==0
   1183  * @param destCapacity the number of chars available at dest
   1184  * @param pErrorCode normal ICU error code;
   1185  *                  common error codes that may be set by this function include
   1186  *                  U_BUFFER_OVERFLOW_ERROR, U_STRING_NOT_TERMINATED_WARNING,
   1187  *                  U_ILLEGAL_ARGUMENT_ERROR, and conversion errors
   1188  * @return the length of the output string, not counting the terminating NUL;
   1189  *         if the length is greater than destCapacity, then the string will not fit
   1190  *         and a buffer of the indicated length would need to be passed in
   1191  * @see ucnv_fromUnicode
   1192  * @see ucnv_convert
   1193  * @see UCNV_GET_MAX_BYTES_FOR_STRING
   1194  * @stable ICU 2.0
   1195  */
   1196 U_STABLE int32_t U_EXPORT2
   1197 ucnv_fromUChars(UConverter *cnv,
   1198                 char *dest, int32_t destCapacity,
   1199                 const UChar *src, int32_t srcLength,
   1200                 UErrorCode *pErrorCode);
   1201 
   1202 /**
   1203  * Convert the codepage string into a Unicode string using an existing UConverter.
   1204  * The output string is NUL-terminated if possible.
   1205  *
   1206  * This function is a more convenient but less powerful version of ucnv_toUnicode().
   1207  * It is only useful for whole strings, not for streaming conversion.
   1208  *
   1209  * The maximum output buffer capacity required (barring output from callbacks) will be
   1210  * 2*srcLength (each char may be converted into a surrogate pair).
   1211  *
   1212  * @param cnv the converter object to be used (ucnv_resetToUnicode() will be called)
   1213  * @param src the input codepage string
   1214  * @param srcLength the input string length, or -1 if NUL-terminated
   1215  * @param dest destination string buffer, can be NULL if destCapacity==0
   1216  * @param destCapacity the number of UChars available at dest
   1217  * @param pErrorCode normal ICU error code;
   1218  *                  common error codes that may be set by this function include
   1219  *                  U_BUFFER_OVERFLOW_ERROR, U_STRING_NOT_TERMINATED_WARNING,
   1220  *                  U_ILLEGAL_ARGUMENT_ERROR, and conversion errors
   1221  * @return the length of the output string, not counting the terminating NUL;
   1222  *         if the length is greater than destCapacity, then the string will not fit
   1223  *         and a buffer of the indicated length would need to be passed in
   1224  * @see ucnv_toUnicode
   1225  * @see ucnv_convert
   1226  * @stable ICU 2.0
   1227  */
   1228 U_STABLE int32_t U_EXPORT2
   1229 ucnv_toUChars(UConverter *cnv,
   1230               UChar *dest, int32_t destCapacity,
   1231               const char *src, int32_t srcLength,
   1232               UErrorCode *pErrorCode);
   1233 
   1234 /**
   1235  * Convert a codepage buffer into Unicode one character at a time.
   1236  * The input is completely consumed when the U_INDEX_OUTOFBOUNDS_ERROR is set.
   1237  *
   1238  * Advantage compared to ucnv_toUnicode() or ucnv_toUChars():
   1239  * - Faster for small amounts of data, for most converters, e.g.,
   1240  *   US-ASCII, ISO-8859-1, UTF-8/16/32, and most "normal" charsets.
   1241  *   (For complex converters, e.g., SCSU, UTF-7 and ISO 2022 variants,
   1242  *    it uses ucnv_toUnicode() internally.)
   1243  * - Convenient.
   1244  *
   1245  * Limitations compared to ucnv_toUnicode():
   1246  * - Always assumes flush=TRUE.
   1247  *   This makes ucnv_getNextUChar() unsuitable for "streaming" conversion,
   1248  *   that is, for where the input is supplied in multiple buffers,
   1249  *   because ucnv_getNextUChar() will assume the end of the input at the end
   1250  *   of the first buffer.
   1251  * - Does not provide offset output.
   1252  *
   1253  * It is possible to "mix" ucnv_getNextUChar() and ucnv_toUnicode() because
   1254  * ucnv_getNextUChar() uses the current state of the converter
   1255  * (unlike ucnv_toUChars() which always resets first).
   1256  * However, if ucnv_getNextUChar() is called after ucnv_toUnicode()
   1257  * stopped in the middle of a character sequence (with flush=FALSE),
   1258  * then ucnv_getNextUChar() will always use the slower ucnv_toUnicode()
   1259  * internally until the next character boundary.
   1260  * (This is new in ICU 2.6. In earlier releases, ucnv_getNextUChar() had to
   1261  * start at a character boundary.)
   1262  *
   1263  * Instead of using ucnv_getNextUChar(), it is recommended
   1264  * to convert using ucnv_toUnicode() or ucnv_toUChars()
   1265  * and then iterate over the text using U16_NEXT() or a UCharIterator (uiter.h)
   1266  * or a C++ CharacterIterator or similar.
   1267  * This allows streaming conversion and offset output, for example.
   1268  *
   1269  * <p>Handling of surrogate pairs and supplementary-plane code points:<br>
   1270  * There are two different kinds of codepages that provide mappings for surrogate characters:
   1271  * <ul>
   1272  *   <li>Codepages like UTF-8, UTF-32, and GB 18030 provide direct representations for Unicode
   1273  *       code points U+10000-U+10ffff as well as for single surrogates U+d800-U+dfff.
   1274  *       Each valid sequence will result in exactly one returned code point.
   1275  *       If a sequence results in a single surrogate, then that will be returned
   1276  *       by itself, even if a neighboring sequence encodes the matching surrogate.</li>
   1277  *   <li>Codepages like SCSU and LMBCS (and UTF-16) provide direct representations only for BMP code points
   1278  *       including surrogates. Code points in supplementary planes are represented with
   1279  *       two sequences, each encoding a surrogate.
   1280  *       For these codepages, matching pairs of surrogates will be combined into single
   1281  *       code points for returning from this function.
   1282  *       (Note that SCSU is actually a mix of these codepage types.)</li>
   1283  * </ul></p>
   1284  *
   1285  * @param converter an open UConverter
   1286  * @param source the address of a pointer to the codepage buffer, will be
   1287  *  updated to point after the bytes consumed in the conversion call.
   1288  * @param sourceLimit points to the end of the input buffer
   1289  * @param err fills in error status (see ucnv_toUnicode)
   1290  * <code>U_INDEX_OUTOFBOUNDS_ERROR</code> will be set if the input
   1291  * is empty or does not convert to any output (e.g.: pure state-change
   1292  * codes SI/SO, escape sequences for ISO 2022,
   1293  * or if the callback did not output anything, ...).
   1294  * This function will not set a <code>U_BUFFER_OVERFLOW_ERROR</code> because
   1295  *  the "buffer" is the return code. However, there might be subsequent output
   1296  *  stored in the converter object
   1297  * that will be returned in following calls to this function.
   1298  * @return a UChar32 resulting from the partial conversion of source
   1299  * @see ucnv_toUnicode
   1300  * @see ucnv_toUChars
   1301  * @see ucnv_convert
   1302  * @stable ICU 2.0
   1303  */
   1304 U_STABLE UChar32 U_EXPORT2
   1305 ucnv_getNextUChar(UConverter * converter,
   1306                   const char **source,
   1307                   const char * sourceLimit,
   1308                   UErrorCode * err);
   1309 
   1310 /**
   1311  * Convert from one external charset to another using two existing UConverters.
   1312  * Internally, two conversions - ucnv_toUnicode() and ucnv_fromUnicode() -
   1313  * are used, "pivoting" through 16-bit Unicode.
   1314  *
   1315  * Important: For streaming conversion (multiple function calls for successive
   1316  * parts of a text stream), the caller must provide a pivot buffer explicitly,
   1317  * and must preserve the pivot buffer and associated pointers from one
   1318  * call to another. (The buffer may be moved if its contents and the relative
   1319  * pointer positions are preserved.)
   1320  *
   1321  * There is a similar function, ucnv_convert(),
   1322  * which has the following limitations:
   1323  * - it takes charset names, not converter objects, so that
   1324  *   - two converters are opened for each call
   1325  *   - only single-string conversion is possible, not streaming operation
   1326  * - it does not provide enough information to find out,
   1327  *   in case of failure, whether the toUnicode or
   1328  *   the fromUnicode conversion failed
   1329  *
   1330  * By contrast, ucnv_convertEx()
   1331  * - takes UConverter parameters instead of charset names
   1332  * - fully exposes the pivot buffer for streaming conversion and complete error handling
   1333  *
   1334  * ucnv_convertEx() also provides further convenience:
   1335  * - an option to reset the converters at the beginning
   1336  *   (if reset==TRUE, see parameters;
   1337  *    also sets *pivotTarget=*pivotSource=pivotStart)
   1338  * - allow NUL-terminated input
   1339  *   (only a single NUL byte, will not work for charsets with multi-byte NULs)
   1340  *   (if sourceLimit==NULL, see parameters)
   1341  * - terminate with a NUL on output
   1342  *   (only a single NUL byte, not useful for charsets with multi-byte NULs),
   1343  *   or set U_STRING_NOT_TERMINATED_WARNING if the output exactly fills
   1344  *   the target buffer
   1345  * - the pivot buffer can be provided internally;
   1346  *   possible only for whole-string conversion, not streaming conversion;
   1347  *   in this case, the caller will not be able to get details about where an
   1348  *   error occurred
   1349  *   (if pivotStart==NULL, see below)
   1350  *
   1351  * The function returns when one of the following is true:
   1352  * - the entire source text has been converted successfully to the target buffer
   1353  * - a target buffer overflow occurred (U_BUFFER_OVERFLOW_ERROR)
   1354  * - a conversion error occurred
   1355  *   (other U_FAILURE(), see description of pErrorCode)
   1356  *
   1357  * Limitation compared to the direct use of
   1358  * ucnv_fromUnicode() and ucnv_toUnicode():
   1359  * ucnv_convertEx() does not provide offset information.
   1360  *
   1361  * Limitation compared to ucnv_fromUChars() and ucnv_toUChars():
   1362  * ucnv_convertEx() does not support preflighting directly.
   1363  *
   1364  * Sample code for converting a single string from
   1365  * one external charset to UTF-8, ignoring the location of errors:
   1366  *
   1367  * \code
   1368  * int32_t
   1369  * myToUTF8(UConverter *cnv,
   1370  *          const char *s, int32_t length,
   1371  *          char *u8, int32_t capacity,
   1372  *          UErrorCode *pErrorCode) {
   1373  *     UConverter *utf8Cnv;
   1374  *     char *target;
   1375  *
   1376  *     if(U_FAILURE(*pErrorCode)) {
   1377  *         return 0;
   1378  *     }
   1379  *
   1380  *     utf8Cnv=myGetCachedUTF8Converter(pErrorCode);
   1381  *     if(U_FAILURE(*pErrorCode)) {
   1382  *         return 0;
   1383  *     }
   1384  *
   1385  *     if(length<0) {
   1386  *         length=strlen(s);
   1387  *     }
   1388  *     target=u8;
   1389  *     ucnv_convertEx(utf8Cnv, cnv,
   1390  *                    &target, u8+capacity,
   1391  *                    &s, s+length,
   1392  *                    NULL, NULL, NULL, NULL,
   1393  *                    TRUE, TRUE,
   1394  *                    pErrorCode);
   1395  *
   1396  *     myReleaseCachedUTF8Converter(utf8Cnv);
   1397  *
   1398  *     // return the output string length, but without preflighting
   1399  *     return (int32_t)(target-u8);
   1400  * }
   1401  * \endcode
   1402  *
   1403  * @param targetCnv     Output converter, used to convert from the UTF-16 pivot
   1404  *                      to the target using ucnv_fromUnicode().
   1405  * @param sourceCnv     Input converter, used to convert from the source to
   1406  *                      the UTF-16 pivot using ucnv_toUnicode().
   1407  * @param target        I/O parameter, same as for ucnv_fromUChars().
   1408  *                      Input: *target points to the beginning of the target buffer.
   1409  *                      Output: *target points to the first unit after the last char written.
   1410  * @param targetLimit   Pointer to the first unit after the target buffer.
   1411  * @param source        I/O parameter, same as for ucnv_toUChars().
   1412  *                      Input: *source points to the beginning of the source buffer.
   1413  *                      Output: *source points to the first unit after the last char read.
   1414  * @param sourceLimit   Pointer to the first unit after the source buffer.
   1415  * @param pivotStart    Pointer to the UTF-16 pivot buffer. If pivotStart==NULL,
   1416  *                      then an internal buffer is used and the other pivot
   1417  *                      arguments are ignored and can be NULL as well.
   1418  * @param pivotSource   I/O parameter, same as source in ucnv_fromUChars() for
   1419  *                      conversion from the pivot buffer to the target buffer.
   1420  * @param pivotTarget   I/O parameter, same as target in ucnv_toUChars() for
   1421  *                      conversion from the source buffer to the pivot buffer.
   1422  *                      It must be pivotStart<=*pivotSource<=*pivotTarget<=pivotLimit
   1423  *                      and pivotStart<pivotLimit (unless pivotStart==NULL).
   1424  * @param pivotLimit    Pointer to the first unit after the pivot buffer.
   1425  * @param reset         If TRUE, then ucnv_resetToUnicode(sourceCnv) and
   1426  *                      ucnv_resetFromUnicode(targetCnv) are called, and the
   1427  *                      pivot pointers are reset (*pivotTarget=*pivotSource=pivotStart).
   1428  * @param flush         If true, indicates the end of the input.
   1429  *                      Passed directly to ucnv_toUnicode(), and carried over to
   1430  *                      ucnv_fromUnicode() when the source is empty as well.
   1431  * @param pErrorCode    ICU error code in/out parameter.
   1432  *                      Must fulfill U_SUCCESS before the function call.
   1433  *                      U_BUFFER_OVERFLOW_ERROR always refers to the target buffer
   1434  *                      because overflows into the pivot buffer are handled internally.
   1435  *                      Other conversion errors are from the source-to-pivot
   1436  *                      conversion if *pivotSource==pivotStart, otherwise from
   1437  *                      the pivot-to-target conversion.
   1438  *
   1439  * @see ucnv_convert
   1440  * @see ucnv_fromAlgorithmic
   1441  * @see ucnv_toAlgorithmic
   1442  * @see ucnv_fromUnicode
   1443  * @see ucnv_toUnicode
   1444  * @see ucnv_fromUChars
   1445  * @see ucnv_toUChars
   1446  * @stable ICU 2.6
   1447  */
   1448 U_STABLE void U_EXPORT2
   1449 ucnv_convertEx(UConverter *targetCnv, UConverter *sourceCnv,
   1450                char **target, const char *targetLimit,
   1451                const char **source, const char *sourceLimit,
   1452                UChar *pivotStart, UChar **pivotSource,
   1453                UChar **pivotTarget, const UChar *pivotLimit,
   1454                UBool reset, UBool flush,
   1455                UErrorCode *pErrorCode);
   1456 
   1457 /**
   1458  * Convert from one external charset to another.
   1459  * Internally, two converters are opened according to the name arguments,
   1460  * then the text is converted to and from the 16-bit Unicode "pivot"
   1461  * using ucnv_convertEx(), then the converters are closed again.
   1462  *
   1463  * This is a convenience function, not an efficient way to convert a lot of text:
   1464  * ucnv_convert()
   1465  * - takes charset names, not converter objects, so that
   1466  *   - two converters are opened for each call
   1467  *   - only single-string conversion is possible, not streaming operation
   1468  * - does not provide enough information to find out,
   1469  *   in case of failure, whether the toUnicode or
   1470  *   the fromUnicode conversion failed
   1471  * - allows NUL-terminated input
   1472  *   (only a single NUL byte, will not work for charsets with multi-byte NULs)
   1473  *   (if sourceLength==-1, see parameters)
   1474  * - terminate with a NUL on output
   1475  *   (only a single NUL byte, not useful for charsets with multi-byte NULs),
   1476  *   or set U_STRING_NOT_TERMINATED_WARNING if the output exactly fills
   1477  *   the target buffer
   1478  * - a pivot buffer is provided internally
   1479  *
   1480  * The function returns when one of the following is true:
   1481  * - the entire source text has been converted successfully to the target buffer
   1482  *   and either the target buffer is terminated with a single NUL byte
   1483  *   or the error code is set to U_STRING_NOT_TERMINATED_WARNING
   1484  * - a target buffer overflow occurred (U_BUFFER_OVERFLOW_ERROR)
   1485  *   and the full output string length is returned ("preflighting")
   1486  * - a conversion error occurred
   1487  *   (other U_FAILURE(), see description of pErrorCode)
   1488  *
   1489  * @param toConverterName   The name of the converter that is used to convert
   1490  *                          from the UTF-16 pivot buffer to the target.
   1491  * @param fromConverterName The name of the converter that is used to convert
   1492  *                          from the source to the UTF-16 pivot buffer.
   1493  * @param target            Pointer to the output buffer.
   1494  * @param targetCapacity    Capacity of the target, in bytes.
   1495  * @param source            Pointer to the input buffer.
   1496  * @param sourceLength      Length of the input text, in bytes, or -1 for NUL-terminated input.
   1497  * @param pErrorCode        ICU error code in/out parameter.
   1498  *                          Must fulfill U_SUCCESS before the function call.
   1499  * @return Length of the complete output text in bytes, even if it exceeds the targetCapacity
   1500  *         and a U_BUFFER_OVERFLOW_ERROR is set.
   1501  *
   1502  * @see ucnv_convertEx
   1503  * @see ucnv_fromAlgorithmic
   1504  * @see ucnv_toAlgorithmic
   1505  * @see ucnv_fromUnicode
   1506  * @see ucnv_toUnicode
   1507  * @see ucnv_fromUChars
   1508  * @see ucnv_toUChars
   1509  * @see ucnv_getNextUChar
   1510  * @stable ICU 2.0
   1511  */
   1512 U_STABLE int32_t U_EXPORT2
   1513 ucnv_convert(const char *toConverterName,
   1514              const char *fromConverterName,
   1515              char *target,
   1516              int32_t targetCapacity,
   1517              const char *source,
   1518              int32_t sourceLength,
   1519              UErrorCode *pErrorCode);
   1520 
   1521 /**
   1522  * Convert from one external charset to another.
   1523  * Internally, the text is converted to and from the 16-bit Unicode "pivot"
   1524  * using ucnv_convertEx(). ucnv_toAlgorithmic() works exactly like ucnv_convert()
   1525  * except that the two converters need not be looked up and opened completely.
   1526  *
   1527  * The source-to-pivot conversion uses the cnv converter parameter.
   1528  * The pivot-to-target conversion uses a purely algorithmic converter
   1529  * according to the specified type, e.g., UCNV_UTF8 for a UTF-8 converter.
   1530  *
   1531  * Internally, the algorithmic converter is opened and closed for each
   1532  * function call, which is more efficient than using the public ucnv_open()
   1533  * but somewhat less efficient than only resetting an existing converter
   1534  * and using ucnv_convertEx().
   1535  *
   1536  * This function is more convenient than ucnv_convertEx() for single-string
   1537  * conversions, especially when "preflighting" is desired (returning the length
   1538  * of the complete output even if it does not fit into the target buffer;
   1539  * see the User Guide Strings chapter). See ucnv_convert() for details.
   1540  *
   1541  * @param algorithmicType   UConverterType constant identifying the desired target
   1542  *                          charset as a purely algorithmic converter.
   1543  *                          Those are converters for Unicode charsets like
   1544  *                          UTF-8, BOCU-1, SCSU, UTF-7, IMAP-mailbox-name, etc.,
   1545  *                          as well as US-ASCII and ISO-8859-1.
   1546  * @param cnv               The converter that is used to convert
   1547  *                          from the source to the UTF-16 pivot buffer.
   1548  * @param target            Pointer to the output buffer.
   1549  * @param targetCapacity    Capacity of the target, in bytes.
   1550  * @param source            Pointer to the input buffer.
   1551  * @param sourceLength      Length of the input text, in bytes
   1552  * @param pErrorCode        ICU error code in/out parameter.
   1553  *                          Must fulfill U_SUCCESS before the function call.
   1554  * @return Length of the complete output text in bytes, even if it exceeds the targetCapacity
   1555  *         and a U_BUFFER_OVERFLOW_ERROR is set.
   1556  *
   1557  * @see ucnv_fromAlgorithmic
   1558  * @see ucnv_convert
   1559  * @see ucnv_convertEx
   1560  * @see ucnv_fromUnicode
   1561  * @see ucnv_toUnicode
   1562  * @see ucnv_fromUChars
   1563  * @see ucnv_toUChars
   1564  * @stable ICU 2.6
   1565  */
   1566 U_STABLE int32_t U_EXPORT2
   1567 ucnv_toAlgorithmic(UConverterType algorithmicType,
   1568                    UConverter *cnv,
   1569                    char *target, int32_t targetCapacity,
   1570                    const char *source, int32_t sourceLength,
   1571                    UErrorCode *pErrorCode);
   1572 
   1573 /**
   1574  * Convert from one external charset to another.
   1575  * Internally, the text is converted to and from the 16-bit Unicode "pivot"
   1576  * using ucnv_convertEx(). ucnv_fromAlgorithmic() works exactly like ucnv_convert()
   1577  * except that the two converters need not be looked up and opened completely.
   1578  *
   1579  * The source-to-pivot conversion uses a purely algorithmic converter
   1580  * according to the specified type, e.g., UCNV_UTF8 for a UTF-8 converter.
   1581  * The pivot-to-target conversion uses the cnv converter parameter.
   1582  *
   1583  * Internally, the algorithmic converter is opened and closed for each
   1584  * function call, which is more efficient than using the public ucnv_open()
   1585  * but somewhat less efficient than only resetting an existing converter
   1586  * and using ucnv_convertEx().
   1587  *
   1588  * This function is more convenient than ucnv_convertEx() for single-string
   1589  * conversions, especially when "preflighting" is desired (returning the length
   1590  * of the complete output even if it does not fit into the target buffer;
   1591  * see the User Guide Strings chapter). See ucnv_convert() for details.
   1592  *
   1593  * @param cnv               The converter that is used to convert
   1594  *                          from the UTF-16 pivot buffer to the target.
   1595  * @param algorithmicType   UConverterType constant identifying the desired source
   1596  *                          charset as a purely algorithmic converter.
   1597  *                          Those are converters for Unicode charsets like
   1598  *                          UTF-8, BOCU-1, SCSU, UTF-7, IMAP-mailbox-name, etc.,
   1599  *                          as well as US-ASCII and ISO-8859-1.
   1600  * @param target            Pointer to the output buffer.
   1601  * @param targetCapacity    Capacity of the target, in bytes.
   1602  * @param source            Pointer to the input buffer.
   1603  * @param sourceLength      Length of the input text, in bytes
   1604  * @param pErrorCode        ICU error code in/out parameter.
   1605  *                          Must fulfill U_SUCCESS before the function call.
   1606  * @return Length of the complete output text in bytes, even if it exceeds the targetCapacity
   1607  *         and a U_BUFFER_OVERFLOW_ERROR is set.
   1608  *
   1609  * @see ucnv_fromAlgorithmic
   1610  * @see ucnv_convert
   1611  * @see ucnv_convertEx
   1612  * @see ucnv_fromUnicode
   1613  * @see ucnv_toUnicode
   1614  * @see ucnv_fromUChars
   1615  * @see ucnv_toUChars
   1616  * @stable ICU 2.6
   1617  */
   1618 U_STABLE int32_t U_EXPORT2
   1619 ucnv_fromAlgorithmic(UConverter *cnv,
   1620                      UConverterType algorithmicType,
   1621                      char *target, int32_t targetCapacity,
   1622                      const char *source, int32_t sourceLength,
   1623                      UErrorCode *pErrorCode);
   1624 
   1625 /**
   1626  * Frees up memory occupied by unused, cached converter shared data.
   1627  *
   1628  * @return the number of cached converters successfully deleted
   1629  * @see ucnv_close
   1630  * @stable ICU 2.0
   1631  */
   1632 U_STABLE int32_t U_EXPORT2
   1633 ucnv_flushCache(void);
   1634 
   1635 /**
   1636  * Returns the number of available converters, as per the alias file.
   1637  *
   1638  * @return the number of available converters
   1639  * @see ucnv_getAvailableName
   1640  * @stable ICU 2.0
   1641  */
   1642 U_STABLE int32_t U_EXPORT2
   1643 ucnv_countAvailable(void);
   1644 
   1645 /**
   1646  * Gets the canonical converter name of the specified converter from a list of
   1647  * all available converters contaied in the alias file. All converters
   1648  * in this list can be opened.
   1649  *
   1650  * @param n the index to a converter available on the system (in the range <TT>[0..ucnv_countAvaiable()]</TT>)
   1651  * @return a pointer a string (library owned), or <TT>NULL</TT> if the index is out of bounds.
   1652  * @see ucnv_countAvailable
   1653  * @stable ICU 2.0
   1654  */
   1655 U_STABLE const char* U_EXPORT2
   1656 ucnv_getAvailableName(int32_t n);
   1657 
   1658 /**
   1659  * Returns a UEnumeration to enumerate all of the canonical converter
   1660  * names, as per the alias file, regardless of the ability to open each
   1661  * converter.
   1662  *
   1663  * @return A UEnumeration object for getting all the recognized canonical
   1664  *   converter names.
   1665  * @see ucnv_getAvailableName
   1666  * @see uenum_close
   1667  * @see uenum_next
   1668  * @stable ICU 2.4
   1669  */
   1670 U_STABLE UEnumeration * U_EXPORT2
   1671 ucnv_openAllNames(UErrorCode *pErrorCode);
   1672 
   1673 /**
   1674  * Gives the number of aliases for a given converter or alias name.
   1675  * If the alias is ambiguous, then the preferred converter is used
   1676  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
   1677  * This method only enumerates the listed entries in the alias file.
   1678  * @param alias alias name
   1679  * @param pErrorCode error status
   1680  * @return number of names on alias list for given alias
   1681  * @stable ICU 2.0
   1682  */
   1683 U_STABLE uint16_t U_EXPORT2
   1684 ucnv_countAliases(const char *alias, UErrorCode *pErrorCode);
   1685 
   1686 /**
   1687  * Gives the name of the alias at given index of alias list.
   1688  * This method only enumerates the listed entries in the alias file.
   1689  * If the alias is ambiguous, then the preferred converter is used
   1690  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
   1691  * @param alias alias name
   1692  * @param n index in alias list
   1693  * @param pErrorCode result of operation
   1694  * @return returns the name of the alias at given index
   1695  * @see ucnv_countAliases
   1696  * @stable ICU 2.0
   1697  */
   1698 U_STABLE const char * U_EXPORT2
   1699 ucnv_getAlias(const char *alias, uint16_t n, UErrorCode *pErrorCode);
   1700 
   1701 /**
   1702  * Fill-up the list of alias names for the given alias.
   1703  * This method only enumerates the listed entries in the alias file.
   1704  * If the alias is ambiguous, then the preferred converter is used
   1705  * and the status is set to U_AMBIGUOUS_ALIAS_WARNING.
   1706  * @param alias alias name
   1707  * @param aliases fill-in list, aliases is a pointer to an array of
   1708  *        <code>ucnv_countAliases()</code> string-pointers
   1709  *        (<code>const char *</code>) that will be filled in.
   1710  *        The strings themselves are owned by the library.
   1711  * @param pErrorCode result of operation
   1712  * @stable ICU 2.0
   1713  */
   1714 U_STABLE void U_EXPORT2
   1715 ucnv_getAliases(const char *alias, const char **aliases, UErrorCode *pErrorCode);
   1716 
   1717 /**
   1718  * Return a new UEnumeration object for enumerating all the
   1719  * alias names for a given converter that are recognized by a standard.
   1720  * This method only enumerates the listed entries in the alias file.
   1721  * The convrtrs.txt file can be modified to change the results of
   1722  * this function.
   1723  * The first result in this list is the same result given by
   1724  * <code>ucnv_getStandardName</code>, which is the default alias for
   1725  * the specified standard name. The returned object must be closed with
   1726  * <code>uenum_close</code> when you are done with the object.
   1727  *
   1728  * @param convName original converter name
   1729  * @param standard name of the standard governing the names; MIME and IANA
   1730  *      are such standards
   1731  * @param pErrorCode The error code
   1732  * @return A UEnumeration object for getting all aliases that are recognized
   1733  *      by a standard. If any of the parameters are invalid, NULL
   1734  *      is returned.
   1735  * @see ucnv_getStandardName
   1736  * @see uenum_close
   1737  * @see uenum_next
   1738  * @stable ICU 2.2
   1739  */
   1740 U_STABLE UEnumeration * U_EXPORT2
   1741 ucnv_openStandardNames(const char *convName,
   1742                        const char *standard,
   1743                        UErrorCode *pErrorCode);
   1744 
   1745 /**
   1746  * Gives the number of standards associated to converter names.
   1747  * @return number of standards
   1748  * @stable ICU 2.0
   1749  */
   1750 U_STABLE uint16_t U_EXPORT2
   1751 ucnv_countStandards(void);
   1752 
   1753 /**
   1754  * Gives the name of the standard at given index of standard list.
   1755  * @param n index in standard list
   1756  * @param pErrorCode result of operation
   1757  * @return returns the name of the standard at given index. Owned by the library.
   1758  * @stable ICU 2.0
   1759  */
   1760 U_STABLE const char * U_EXPORT2
   1761 ucnv_getStandard(uint16_t n, UErrorCode *pErrorCode);
   1762 
   1763 /**
   1764  * Returns a standard name for a given converter name.
   1765  * <p>
   1766  * Example alias table:<br>
   1767  * conv alias1 { STANDARD1 } alias2 { STANDARD1* }
   1768  * <p>
   1769  * Result of ucnv_getStandardName("conv", "STANDARD1") from example
   1770  * alias table:<br>
   1771  * <b>"alias2"</b>
   1772  *
   1773  * @param name original converter name
   1774  * @param standard name of the standard governing the names; MIME and IANA
   1775  *        are such standards
   1776  * @param pErrorCode result of operation
   1777  * @return returns the standard converter name;
   1778  *         if a standard converter name cannot be determined,
   1779  *         then <code>NULL</code> is returned. Owned by the library.
   1780  * @stable ICU 2.0
   1781  */
   1782 U_STABLE const char * U_EXPORT2
   1783 ucnv_getStandardName(const char *name, const char *standard, UErrorCode *pErrorCode);
   1784 
   1785 /**
   1786  * This function will return the internal canonical converter name of the
   1787  * tagged alias. This is the opposite of ucnv_openStandardNames, which
   1788  * returns the tagged alias given the canonical name.
   1789  * <p>
   1790  * Example alias table:<br>
   1791  * conv alias1 { STANDARD1 } alias2 { STANDARD1* }
   1792  * <p>
   1793  * Result of ucnv_getStandardName("alias1", "STANDARD1") from example
   1794  * alias table:<br>
   1795  * <b>"conv"</b>
   1796  *
   1797  * @return returns the canonical converter name;
   1798  *         if a standard or alias name cannot be determined,
   1799  *         then <code>NULL</code> is returned. The returned string is
   1800  *         owned by the library.
   1801  * @see ucnv_getStandardName
   1802  * @stable ICU 2.4
   1803  */
   1804 U_STABLE const char * U_EXPORT2
   1805 ucnv_getCanonicalName(const char *alias, const char *standard, UErrorCode *pErrorCode);
   1806 
   1807 /**
   1808  * Returns the current default converter name. If you want to open
   1809  * a default converter, you do not need to use this function.
   1810  * It is faster if you pass a NULL argument to ucnv_open the
   1811  * default converter.
   1812  *
   1813  * If U_CHARSET_IS_UTF8 is defined to 1 in utypes.h then this function
   1814  * always returns "UTF-8".
   1815  *
   1816  * @return returns the current default converter name.
   1817  *         Storage owned by the library
   1818  * @see ucnv_setDefaultName
   1819  * @stable ICU 2.0
   1820  */
   1821 U_STABLE const char * U_EXPORT2
   1822 ucnv_getDefaultName(void);
   1823 
   1824 /**
   1825  * This function is not thread safe. DO NOT call this function when ANY ICU
   1826  * function is being used from more than one thread! This function sets the
   1827  * current default converter name. If this function needs to be called, it
   1828  * should be called during application initialization. Most of the time, the
   1829  * results from ucnv_getDefaultName() or ucnv_open with a NULL string argument
   1830  * is sufficient for your application.
   1831  *
   1832  * If U_CHARSET_IS_UTF8 is defined to 1 in utypes.h then this function
   1833  * does nothing.
   1834  *
   1835  * @param name the converter name to be the default (must be known by ICU).
   1836  * @see ucnv_getDefaultName
   1837  * @system
   1838  * @stable ICU 2.0
   1839  */
   1840 U_STABLE void U_EXPORT2
   1841 ucnv_setDefaultName(const char *name);
   1842 
   1843 /**
   1844  * Fixes the backslash character mismapping.  For example, in SJIS, the backslash
   1845  * character in the ASCII portion is also used to represent the yen currency sign.
   1846  * When mapping from Unicode character 0x005C, it's unclear whether to map the
   1847  * character back to yen or backslash in SJIS.  This function will take the input
   1848  * buffer and replace all the yen sign characters with backslash.  This is necessary
   1849  * when the user tries to open a file with the input buffer on Windows.
   1850  * This function will test the converter to see whether such mapping is
   1851  * required.  You can sometimes avoid using this function by using the correct version
   1852  * of Shift-JIS.
   1853  *
   1854  * @param cnv The converter representing the target codepage.
   1855  * @param source the input buffer to be fixed
   1856  * @param sourceLen the length of the input buffer
   1857  * @see ucnv_isAmbiguous
   1858  * @stable ICU 2.0
   1859  */
   1860 U_STABLE void U_EXPORT2
   1861 ucnv_fixFileSeparator(const UConverter *cnv, UChar *source, int32_t sourceLen);
   1862 
   1863 /**
   1864  * Determines if the converter contains ambiguous mappings of the same
   1865  * character or not.
   1866  * @param cnv the converter to be tested
   1867  * @return TRUE if the converter contains ambiguous mapping of the same
   1868  * character, FALSE otherwise.
   1869  * @stable ICU 2.0
   1870  */
   1871 U_STABLE UBool U_EXPORT2
   1872 ucnv_isAmbiguous(const UConverter *cnv);
   1873 
   1874 /**
   1875  * Sets the converter to use fallback mappings or not.
   1876  * Regardless of this flag, the converter will always use
   1877  * fallbacks from Unicode Private Use code points, as well as
   1878  * reverse fallbacks (to Unicode).
   1879  * For details see ".ucm File Format"
   1880  * in the Conversion Data chapter of the ICU User Guide:
   1881  * http://www.icu-project.org/userguide/conversion-data.html#ucmformat
   1882  *
   1883  * @param cnv The converter to set the fallback mapping usage on.
   1884  * @param usesFallback TRUE if the user wants the converter to take advantage of the fallback
   1885  * mapping, FALSE otherwise.
   1886  * @stable ICU 2.0
   1887  * @see ucnv_usesFallback
   1888  */
   1889 U_STABLE void U_EXPORT2
   1890 ucnv_setFallback(UConverter *cnv, UBool usesFallback);
   1891 
   1892 /**
   1893  * Determines if the converter uses fallback mappings or not.
   1894  * This flag has restrictions, see ucnv_setFallback().
   1895  *
   1896  * @param cnv The converter to be tested
   1897  * @return TRUE if the converter uses fallback, FALSE otherwise.
   1898  * @stable ICU 2.0
   1899  * @see ucnv_setFallback
   1900  */
   1901 U_STABLE UBool U_EXPORT2
   1902 ucnv_usesFallback(const UConverter *cnv);
   1903 
   1904 /**
   1905  * Detects Unicode signature byte sequences at the start of the byte stream
   1906  * and returns the charset name of the indicated Unicode charset.
   1907  * NULL is returned when no Unicode signature is recognized.
   1908  * The number of bytes in the signature is output as well.
   1909  *
   1910  * The caller can ucnv_open() a converter using the charset name.
   1911  * The first code unit (UChar) from the start of the stream will be U+FEFF
   1912  * (the Unicode BOM/signature character) and can usually be ignored.
   1913  *
   1914  * For most Unicode charsets it is also possible to ignore the indicated
   1915  * number of initial stream bytes and start converting after them.
   1916  * However, there are stateful Unicode charsets (UTF-7 and BOCU-1) for which
   1917  * this will not work. Therefore, it is best to ignore the first output UChar
   1918  * instead of the input signature bytes.
   1919  * <p>
   1920  * Usage:
   1921  * @code
   1922  *      UErrorCode err = U_ZERO_ERROR;
   1923  *      char input[] = { '\xEF','\xBB', '\xBF','\x41','\x42','\x43' };
   1924  *      int32_t signatureLength = 0;
   1925  *      char *encoding = ucnv_detectUnicodeSignature(input,sizeof(input),&signatureLength,&err);
   1926  *      UConverter *conv = NULL;
   1927  *      UChar output[100];
   1928  *      UChar *target = output, *out;
   1929  *      char *source = input;
   1930  *      if(encoding!=NULL && U_SUCCESS(err)){
   1931  *          // should signature be discarded ?
   1932  *          conv = ucnv_open(encoding, &err);
   1933  *          // do the conversion
   1934  *          ucnv_toUnicode(conv,
   1935  *                         target, output + sizeof(output)/U_SIZEOF_UCHAR,
   1936  *                         source, input + sizeof(input),
   1937  *                         NULL, TRUE, &err);
   1938  *          out = output;
   1939  *          if (discardSignature){
   1940  *              ++out; // ignore initial U+FEFF
   1941  *          }
   1942  *          while(out != target) {
   1943  *              printf("%04x ", *out++);
   1944  *          }
   1945  *          puts("");
   1946  *      }
   1947  *
   1948  * @endcode
   1949  *
   1950  * @param source            The source string in which the signature should be detected.
   1951  * @param sourceLength      Length of the input string, or -1 if terminated with a NUL byte.
   1952  * @param signatureLength   A pointer to int32_t to receive the number of bytes that make up the signature
   1953  *                          of the detected UTF. 0 if not detected.
   1954  *                          Can be a NULL pointer.
   1955  * @param pErrorCode        ICU error code in/out parameter.
   1956  *                          Must fulfill U_SUCCESS before the function call.
   1957  * @return The name of the encoding detected. NULL if encoding is not detected.
   1958  * @stable ICU 2.4
   1959  */
   1960 U_STABLE const char* U_EXPORT2
   1961 ucnv_detectUnicodeSignature(const char* source,
   1962                             int32_t sourceLength,
   1963                             int32_t *signatureLength,
   1964                             UErrorCode *pErrorCode);
   1965 
   1966 /**
   1967  * Returns the number of UChars held in the converter's internal state
   1968  * because more input is needed for completing the conversion. This function is
   1969  * useful for mapping semantics of ICU's converter interface to those of iconv,
   1970  * and this information is not needed for normal conversion.
   1971  * @param cnv       The converter in which the input is held
   1972  * @param status    ICU error code in/out parameter.
   1973  *                  Must fulfill U_SUCCESS before the function call.
   1974  * @return The number of UChars in the state. -1 if an error is encountered.
   1975  * @stable ICU 3.4
   1976  */
   1977 U_STABLE int32_t U_EXPORT2
   1978 ucnv_fromUCountPending(const UConverter* cnv, UErrorCode* status);
   1979 
   1980 /**
   1981  * Returns the number of chars held in the converter's internal state
   1982  * because more input is needed for completing the conversion. This function is
   1983  * useful for mapping semantics of ICU's converter interface to those of iconv,
   1984  * and this information is not needed for normal conversion.
   1985  * @param cnv       The converter in which the input is held as internal state
   1986  * @param status    ICU error code in/out parameter.
   1987  *                  Must fulfill U_SUCCESS before the function call.
   1988  * @return The number of chars in the state. -1 if an error is encountered.
   1989  * @stable ICU 3.4
   1990  */
   1991 U_STABLE int32_t U_EXPORT2
   1992 ucnv_toUCountPending(const UConverter* cnv, UErrorCode* status);
   1993 
   1994 #endif
   1995 
   1996 #endif
   1997 /*_UCNV*/
   1998