Check in the pristine copy of ICU 4.6...

icu46/source/common/ucnv_cnv.h

+/*
+**********************************************************************
+*   Copyright (C) 1999-2009, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+**********************************************************************
+*
+*   ucnv_cnv.h:
+*   Definitions for converter implementations.
+*
+* Modification History:
+*
+*   Date        Name        Description
+*   05/09/00    helena      Added implementation to handle fallback mappings.
+*   06/29/2000  helena      Major rewrite of the callback APIs.
+*/
+
+#ifndef UCNV_CNV_H
+#define UCNV_CNV_H
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_CONVERSION
+
+#include "unicode/ucnv.h"
+#include "unicode/ucnv_err.h"
+#include "unicode/uset.h"
+#include "uset_imp.h"
+
+U_CDECL_BEGIN
+
+/* this is used in fromUnicode DBCS tables as an "unassigned" marker */
+#define missingCharMarker 0xFFFF
+
+/*
+ * #define missingUCharMarker 0xfffe
+ *
+ * commented out because there are actually two values used in toUnicode tables:
+ * U+fffe "unassigned"
+ * U+ffff "illegal"
+ */
+
+/** Forward declaration, see ucnv_bld.h */
+struct UConverterSharedData;
+typedef struct UConverterSharedData UConverterSharedData;
+
+/* function types for UConverterImpl ---------------------------------------- */
+
+/* struct with arguments for UConverterLoad and ucnv_load() */
+typedef struct {
+    int32_t size;               /* sizeof(UConverterLoadArgs) */
+    int32_t nestedLoads;        /* count nested ucnv_load() calls */
+    UBool onlyTestIsLoadable;   /* input: don't actually load */
+    UBool reserved0;            /* reserved - for good alignment of the pointers */
+    int16_t reserved;           /* reserved - for good alignment of the pointers */
+    uint32_t options;
+    const char *pkg, *name, *locale;
+} UConverterLoadArgs;
+
+typedef void (*UConverterLoad) (UConverterSharedData *sharedData,
+                                UConverterLoadArgs *pArgs,
+                                const uint8_t *raw, UErrorCode *pErrorCode);
+typedef void (*UConverterUnload) (UConverterSharedData *sharedData);
+
+typedef void (*UConverterOpen) (UConverter *cnv, UConverterLoadArgs *pArgs, UErrorCode *pErrorCode);
+typedef void (*UConverterClose) (UConverter *cnv);
+
+typedef enum UConverterResetChoice {
+    UCNV_RESET_BOTH,
+    UCNV_RESET_TO_UNICODE,
+    UCNV_RESET_FROM_UNICODE
+} UConverterResetChoice;
+
+typedef void (*UConverterReset) (UConverter *cnv, UConverterResetChoice choice);
+
+/*
+ * Converter implementation function(s) for ucnv_toUnicode().
+ * If the toUnicodeWithOffsets function pointer is NULL,
+ * then the toUnicode function will be used and the offsets will be set to -1.
+ *
+ * Must maintain state across buffers. Use toUBytes[toULength] for partial input
+ * sequences; it will be checked in ucnv.c at the end of the input stream
+ * to detect truncated input.
+ * Some converters may need additional detection and may then set U_TRUNCATED_CHAR_FOUND.
+ *
+ * The toUnicodeWithOffsets must write exactly as many offset values as target
+ * units. Write offset values of -1 for when the source index corresponding to
+ * the output unit is not known (e.g., the character started in an earlier buffer).
+ * The pArgs->offsets pointer need not be moved forward.
+ *
+ * At function return, either one of the following conditions must be true:
+ * - U_BUFFER_OVERFLOW_ERROR and the target is full: target==targetLimit
+ * - another error code with toUBytes[toULength] set to the offending input
+ * - no error, and the source is consumed: source==sourceLimit
+ *
+ * The ucnv.c code will handle the end of the input (reset)
+ * (reset, and truncation detection) and callbacks.
+ */
+typedef void (*UConverterToUnicode) (UConverterToUnicodeArgs *, UErrorCode *);
+
+/*
+ * Same rules as for UConverterToUnicode.
+ * A lead surrogate is kept in fromUChar32 across buffers, and if an error
+ * occurs, then the offending input code point must be put into fromUChar32
+ * as well.
+ */
+typedef void (*UConverterFromUnicode) (UConverterFromUnicodeArgs *, UErrorCode *);
+
+/*
+ * Converter implementation function for ucnv_convertEx(), for direct conversion
+ * between two charsets without pivoting through UTF-16.
+ * The rules are the same as for UConverterToUnicode and UConverterFromUnicode.
+ * In addition,
+ * - The toUnicode side must behave and keep state exactly like the
+ *   UConverterToUnicode implementation for the same source charset.
+ * - A U_USING_DEFAULT_WARNING can be set to request to temporarily fall back
+ *   to pivoting. When this function is called, the conversion framework makes
+ *   sure that this warning is not set on input.
+ * - Continuing a partial match and flushing the toUnicode replay buffer
+ *   are handled by pivoting, using the toUnicode and fromUnicode functions.
+ */
+typedef void (*UConverterConvert) (UConverterFromUnicodeArgs *pFromUArgs,
+                                   UConverterToUnicodeArgs *pToUArgs,
+                                   UErrorCode *pErrorCode);
+
+/*
+ * Converter implementation function for ucnv_getNextUChar().
+ * If the function pointer is NULL, then the toUnicode function will be used.
+ *
+ * Will be called at a character boundary (toULength==0).
+ * May return with
+ * - U_INDEX_OUTOFBOUNDS_ERROR if there was no output for the input
+ *   (the return value will be ignored)
+ * - U_TRUNCATED_CHAR_FOUND or another error code (never U_BUFFER_OVERFLOW_ERROR!)
+ *   with toUBytes[toULength] set to the offending input
+ *   (the return value will be ignored)
+ * - return UCNV_GET_NEXT_UCHAR_USE_TO_U, without moving the source pointer,
+ *   to indicate that the ucnv.c code shall call the toUnicode function instead
+ * - return a real code point result
+ *
+ * Unless UCNV_GET_NEXT_UCHAR_USE_TO_U is returned, the source bytes must be consumed.
+ *
+ * The ucnv.c code will handle the end of the input (reset)
+ * (except for truncation detection!) and callbacks.
+ */
+typedef UChar32 (*UConverterGetNextUChar) (UConverterToUnicodeArgs *, UErrorCode *);
+
+typedef void (*UConverterGetStarters)(const UConverter* converter,
+                                      UBool starters[256],
+                                      UErrorCode *pErrorCode);
+
+/* If this function pointer is null or if the function returns null
+ * the name field in static data struct should be returned by 
+ * ucnv_getName() API function
+ */
+typedef const char * (*UConverterGetName) (const UConverter *cnv);
+
+/**
+ * Write the codepage substitution character.
+ * If this function is not set, then ucnv_cbFromUWriteSub() writes
+ * the substitution character from UConverter.
+ * For stateful converters, it is typically necessary to handle this
+ * specificially for the converter in order to properly maintain the state.
+ */
+typedef void (*UConverterWriteSub) (UConverterFromUnicodeArgs *pArgs, int32_t offsetIndex, UErrorCode *pErrorCode);
+
+/**
+ * For converter-specific safeClone processing
+ * If this function is not set, then ucnv_safeClone assumes that the converter has no private data that changes
+ * after the converter is done opening.
+ * If this function is set, then it is called just after a memcpy() of
+ * converter data to the new, empty converter, and is expected to set up
+ * the initial state of the converter.  It is not expected to increment the
+ * reference counts of the standard data types such as the shared data.
+ */
+typedef UConverter * (*UConverterSafeClone) (const UConverter   *cnv, 
+                                             void               *stackBuffer,
+                                             int32_t            *pBufferSize, 
+                                             UErrorCode         *status);
+
+/**
+ * Filters for some ucnv_getUnicodeSet() implementation code.
+ */
+typedef enum UConverterSetFilter {
+    UCNV_SET_FILTER_NONE,
+    UCNV_SET_FILTER_DBCS_ONLY,
+    UCNV_SET_FILTER_2022_CN,
+    UCNV_SET_FILTER_SJIS,
+    UCNV_SET_FILTER_GR94DBCS,
+    UCNV_SET_FILTER_HZ,
+    UCNV_SET_FILTER_COUNT
+} UConverterSetFilter;
+
+/**
+ * Fills the set of Unicode code points that can be converted by an ICU converter.
+ * The API function ucnv_getUnicodeSet() clears the USet before calling
+ * the converter's getUnicodeSet() implementation; the converter should only
+ * add the appropriate code points to allow recursive use.
+ * For example, the ISO-2022-JP converter will call each subconverter's
+ * getUnicodeSet() implementation to consecutively add code points to
+ * the same USet, which will result in a union of the sets of all subconverters.
+ *
+ * For more documentation, see ucnv_getUnicodeSet() in ucnv.h.
+ */
+typedef void (*UConverterGetUnicodeSet) (const UConverter *cnv,
+                                         const USetAdder *sa,
+                                         UConverterUnicodeSet which,
+                                         UErrorCode *pErrorCode);
+
+UBool CONVERSION_U_SUCCESS (UErrorCode err);
+
+/**
+ * UConverterImpl contains all the data and functions for a converter type.
+ * Its function pointers work much like a C++ vtable.
+ * Many converter types need to define only a subset of the functions;
+ * when a function pointer is NULL, then a default action will be performed.
+ *
+ * Every converter type must implement toUnicode, fromUnicode, and getNextUChar,
+ * otherwise the converter may crash.
+ * Every converter type that has variable-length codepage sequences should
+ * also implement toUnicodeWithOffsets and fromUnicodeWithOffsets for
+ * correct offset handling.
+ * All other functions may or may not be implemented - it depends only on
+ * whether the converter type needs them.
+ *
+ * When open() fails, then close() will be called, if present.
+ */
+struct UConverterImpl {
+    UConverterType type;
+
+    UConverterLoad load;
+    UConverterUnload unload;
+
+    UConverterOpen open;
+    UConverterClose close;
+    UConverterReset reset;
+
+    UConverterToUnicode toUnicode;
+    UConverterToUnicode toUnicodeWithOffsets;
+    UConverterFromUnicode fromUnicode;
+    UConverterFromUnicode fromUnicodeWithOffsets;
+    UConverterGetNextUChar getNextUChar;
+
+    UConverterGetStarters getStarters;
+    UConverterGetName getName;
+    UConverterWriteSub writeSub;
+    UConverterSafeClone safeClone;
+    UConverterGetUnicodeSet getUnicodeSet;
+
+    UConverterConvert toUTF8;
+    UConverterConvert fromUTF8;
+};
+
+extern const UConverterSharedData
+    _MBCSData, _Latin1Data,
+    _UTF8Data, _UTF16BEData, _UTF16LEData, _UTF32BEData, _UTF32LEData,
+    _ISO2022Data, 
+    _LMBCSData1,_LMBCSData2, _LMBCSData3, _LMBCSData4, _LMBCSData5, _LMBCSData6,
+    _LMBCSData8,_LMBCSData11,_LMBCSData16,_LMBCSData17,_LMBCSData18,_LMBCSData19,
+    _HZData,_ISCIIData, _SCSUData, _ASCIIData,
+    _UTF7Data, _Bocu1Data, _UTF16Data, _UTF32Data, _CESU8Data, _IMAPData;
+
+U_CDECL_END
+
+/** Always use fallbacks from codepage to Unicode */
+#define TO_U_USE_FALLBACK(useFallback) TRUE
+#define UCNV_TO_U_USE_FALLBACK(cnv) TRUE
+
+/** Use fallbacks from Unicode to codepage when cnv->useFallback or for private-use code points */
+#define IS_PRIVATE_USE(c) ((uint32_t)((c)-0xe000)<0x1900 || (uint32_t)((c)-0xf0000)<0x20000)
+#define FROM_U_USE_FALLBACK(useFallback, c) ((useFallback) || IS_PRIVATE_USE(c))
+#define UCNV_FROM_U_USE_FALLBACK(cnv, c) FROM_U_USE_FALLBACK((cnv)->useFallback, c)
+
+/**
+ * Magic number for ucnv_getNextUChar(), returned by a
+ * getNextUChar() implementation to indicate to use the converter's toUnicode()
+ * instead of the native function.
+ * @internal
+ */
+#define UCNV_GET_NEXT_UCHAR_USE_TO_U -9
+
+U_CFUNC void
+ucnv_getCompleteUnicodeSet(const UConverter *cnv,
+                   const USetAdder *sa,
+                   UConverterUnicodeSet which,
+                   UErrorCode *pErrorCode);
+
+U_CFUNC void
+ucnv_getNonSurrogateUnicodeSet(const UConverter *cnv,
+                               const USetAdder *sa,
+                               UConverterUnicodeSet which,
+                               UErrorCode *pErrorCode);
+
+U_CFUNC void
+ucnv_fromUWriteBytes(UConverter *cnv,
+                     const char *bytes, int32_t length,
+                     char **target, const char *targetLimit,
+                     int32_t **offsets,
+                     int32_t sourceIndex,
+                     UErrorCode *pErrorCode);
+U_CFUNC void
+ucnv_toUWriteUChars(UConverter *cnv,
+                    const UChar *uchars, int32_t length,
+                    UChar **target, const UChar *targetLimit,
+                    int32_t **offsets,
+                    int32_t sourceIndex,
+                    UErrorCode *pErrorCode);
+
+U_CFUNC void
+ucnv_toUWriteCodePoint(UConverter *cnv,
+                       UChar32 c,
+                       UChar **target, const UChar *targetLimit,
+                       int32_t **offsets,
+                       int32_t sourceIndex,
+                       UErrorCode *pErrorCode);
+
+#endif
+
+#endif /* UCNV_CNV */