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      1 /*
      2 ******************************************************************************
      3 *
      4 *   Copyright (C) 1999-2007, International Business Machines
      5 *   Corporation and others.  All Rights Reserved.
      6 *
      7 ******************************************************************************
      8 *   file name:  ubidiimp.h
      9 *   encoding:   US-ASCII
     10 *   tab size:   8 (not used)
     11 *   indentation:4
     12 *
     13 *   created on: 1999aug06
     14 *   created by: Markus W. Scherer, updated by Matitiahu Allouche
     15 */
     16 
     17 #ifndef UBIDIIMP_H
     18 #define UBIDIIMP_H
     19 
     20 /* set import/export definitions */
     21 #ifdef U_COMMON_IMPLEMENTATION
     22 
     23 #include "unicode/utypes.h"
     24 #include "unicode/uchar.h"
     25 #include "ubidi_props.h"
     26 
     27 /* miscellaneous definitions ---------------------------------------------- */
     28 
     29 typedef uint8_t DirProp;
     30 typedef uint32_t Flags;
     31 
     32 /*  Comparing the description of the BiDi algorithm with this implementation
     33     is easier with the same names for the BiDi types in the code as there.
     34     See UCharDirection in uchar.h .
     35 */
     36 enum {
     37     L=  U_LEFT_TO_RIGHT,
     38     R=  U_RIGHT_TO_LEFT,
     39     EN= U_EUROPEAN_NUMBER,
     40     ES= U_EUROPEAN_NUMBER_SEPARATOR,
     41     ET= U_EUROPEAN_NUMBER_TERMINATOR,
     42     AN= U_ARABIC_NUMBER,
     43     CS= U_COMMON_NUMBER_SEPARATOR,
     44     B=  U_BLOCK_SEPARATOR,
     45     S=  U_SEGMENT_SEPARATOR,
     46     WS= U_WHITE_SPACE_NEUTRAL,
     47     ON= U_OTHER_NEUTRAL,
     48     LRE=U_LEFT_TO_RIGHT_EMBEDDING,
     49     LRO=U_LEFT_TO_RIGHT_OVERRIDE,
     50     AL= U_RIGHT_TO_LEFT_ARABIC,
     51     RLE=U_RIGHT_TO_LEFT_EMBEDDING,
     52     RLO=U_RIGHT_TO_LEFT_OVERRIDE,
     53     PDF=U_POP_DIRECTIONAL_FORMAT,
     54     NSM=U_DIR_NON_SPACING_MARK,
     55     BN= U_BOUNDARY_NEUTRAL,
     56     dirPropCount
     57 };
     58 
     59 /*
     60  * Sometimes, bit values are more appropriate
     61  * to deal with directionality properties.
     62  * Abbreviations in these macro names refer to names
     63  * used in the BiDi algorithm.
     64  */
     65 #define DIRPROP_FLAG(dir) (1UL<<(dir))
     66 
     67 /* special flag for multiple runs from explicit embedding codes */
     68 #define DIRPROP_FLAG_MULTI_RUNS (1UL<<31)
     69 
     70 /* are there any characters that are LTR or RTL? */
     71 #define MASK_LTR (DIRPROP_FLAG(L)|DIRPROP_FLAG(EN)|DIRPROP_FLAG(AN)|DIRPROP_FLAG(LRE)|DIRPROP_FLAG(LRO))
     72 #define MASK_RTL (DIRPROP_FLAG(R)|DIRPROP_FLAG(AL)|DIRPROP_FLAG(RLE)|DIRPROP_FLAG(RLO))
     73 #define MASK_R_AL (DIRPROP_FLAG(R)|DIRPROP_FLAG(AL))
     74 
     75 /* explicit embedding codes */
     76 #define MASK_LRX (DIRPROP_FLAG(LRE)|DIRPROP_FLAG(LRO))
     77 #define MASK_RLX (DIRPROP_FLAG(RLE)|DIRPROP_FLAG(RLO))
     78 #define MASK_OVERRIDE (DIRPROP_FLAG(LRO)|DIRPROP_FLAG(RLO))
     79 
     80 #define MASK_EXPLICIT (MASK_LRX|MASK_RLX|DIRPROP_FLAG(PDF))
     81 #define MASK_BN_EXPLICIT (DIRPROP_FLAG(BN)|MASK_EXPLICIT)
     82 
     83 /* paragraph and segment separators */
     84 #define MASK_B_S (DIRPROP_FLAG(B)|DIRPROP_FLAG(S))
     85 
     86 /* all types that are counted as White Space or Neutral in some steps */
     87 #define MASK_WS (MASK_B_S|DIRPROP_FLAG(WS)|MASK_BN_EXPLICIT)
     88 #define MASK_N (DIRPROP_FLAG(ON)|MASK_WS)
     89 
     90 /* all types that are included in a sequence of European Terminators for (W5) */
     91 #define MASK_ET_NSM_BN (DIRPROP_FLAG(ET)|DIRPROP_FLAG(NSM)|MASK_BN_EXPLICIT)
     92 
     93 /* types that are neutrals or could becomes neutrals in (Wn) */
     94 #define MASK_POSSIBLE_N (DIRPROP_FLAG(CS)|DIRPROP_FLAG(ES)|DIRPROP_FLAG(ET)|MASK_N)
     95 
     96 /*
     97  * These types may be changed to "e",
     98  * the embedding type (L or R) of the run,
     99  * in the BiDi algorithm (N2)
    100  */
    101 #define MASK_EMBEDDING (DIRPROP_FLAG(NSM)|MASK_POSSIBLE_N)
    102 
    103 /* the dirProp's L and R are defined to 0 and 1 values in UCharDirection */
    104 #define GET_LR_FROM_LEVEL(level) ((DirProp)((level)&1))
    105 
    106 #define IS_DEFAULT_LEVEL(level) ((level)>=0xfe)
    107 
    108 /*
    109  * The following bit is ORed to the property of characters in paragraphs
    110  * with contextual RTL direction when paraLevel is contextual.
    111  */
    112 #define CONTEXT_RTL 0x80
    113 #define NO_CONTEXT_RTL(dir) ((dir)&~CONTEXT_RTL)
    114 /*
    115  * The following is a variant of DIRPROP_FLAG which ignores the CONTEXT_RTL bit.
    116  */
    117 #define DIRPROP_FLAG_NC(dir) (1UL<<(NO_CONTEXT_RTL(dir)))
    118 
    119 #define GET_PARALEVEL(ubidi, index) \
    120             (UBiDiLevel)((ubidi)->defaultParaLevel ? (ubidi)->dirProps[index]>>7 \
    121                                                    : (ubidi)->paraLevel)
    122 
    123 /* Paragraph type for multiple paragraph support ---------------------------- */
    124 typedef int32_t Para;
    125 
    126 #define CR  0x000D
    127 #define LF  0x000A
    128 
    129 /* Run structure for reordering --------------------------------------------- */
    130 enum {
    131     LRM_BEFORE=1,
    132     LRM_AFTER=2,
    133     RLM_BEFORE=4,
    134     RLM_AFTER=8
    135 };
    136 
    137 typedef struct Run {
    138     int32_t logicalStart,   /* first character of the run; b31 indicates even/odd level */
    139             visualLimit,    /* last visual position of the run +1 */
    140             insertRemove;   /* if >0, flags for inserting LRM/RLM before/after run,
    141                                if <0, count of bidi controls within run            */
    142 } Run;
    143 
    144 /* in a Run, logicalStart will get this bit set if the run level is odd */
    145 #define INDEX_ODD_BIT (1UL<<31)
    146 
    147 #define MAKE_INDEX_ODD_PAIR(index, level) ((index)|((int32_t)(level)<<31))
    148 #define ADD_ODD_BIT_FROM_LEVEL(x, level)  ((x)|=((int32_t)(level)<<31))
    149 #define REMOVE_ODD_BIT(x)                 ((x)&=~INDEX_ODD_BIT)
    150 
    151 #define GET_INDEX(x)   ((x)&~INDEX_ODD_BIT)
    152 #define GET_ODD_BIT(x) ((uint32_t)(x)>>31)
    153 #define IS_ODD_RUN(x)  ((UBool)(((x)&INDEX_ODD_BIT)!=0))
    154 #define IS_EVEN_RUN(x) ((UBool)(((x)&INDEX_ODD_BIT)==0))
    155 
    156 U_CFUNC UBool
    157 ubidi_getRuns(UBiDi *pBiDi, UErrorCode *pErrorCode);
    158 
    159 /** BiDi control code points */
    160 enum {
    161     ZWNJ_CHAR=0x200c,
    162     ZWJ_CHAR,
    163     LRM_CHAR,
    164     RLM_CHAR,
    165     LRE_CHAR=0x202a,
    166     RLE_CHAR,
    167     PDF_CHAR,
    168     LRO_CHAR,
    169     RLO_CHAR
    170 };
    171 
    172 #define IS_BIDI_CONTROL_CHAR(c) (((uint32_t)(c)&0xfffffffc)==ZWNJ_CHAR || (uint32_t)((c)-LRE_CHAR)<5)
    173 
    174 /* InsertPoints structure for noting where to put BiDi marks ---------------- */
    175 
    176 typedef struct Point {
    177     int32_t pos;            /* position in text */
    178     int32_t flag;           /* flag for LRM/RLM, before/after */
    179 } Point;
    180 
    181 typedef struct InsertPoints {
    182     int32_t capacity;       /* number of points allocated */
    183     int32_t size;           /* number of points used */
    184     int32_t confirmed;      /* number of points confirmed */
    185     UErrorCode errorCode;   /* for eventual memory shortage */
    186     Point *points;          /* pointer to array of points */
    187 } InsertPoints;
    188 
    189 
    190 /* UBiDi structure ----------------------------------------------------------- */
    191 
    192 struct UBiDi {
    193     /* pointer to parent paragraph object (pointer to self if this object is
    194      * a paragraph object); set to NULL in a newly opened object; set to a
    195      * real value after a successful execution of ubidi_setPara or ubidi_setLine
    196      */
    197     const UBiDi * pParaBiDi;
    198 
    199     const UBiDiProps *bdp;
    200 
    201     /* alias pointer to the current text */
    202     const UChar *text;
    203 
    204     /* length of the current text */
    205     int32_t originalLength;
    206 
    207     /* if the UBIDI_OPTION_STREAMING option is set, this is the length
    208      * of text actually processed by ubidi_setPara, which may be shorter than
    209      * the original length.
    210      * Otherwise, it is identical to the original length.
    211      */
    212     int32_t length;
    213 
    214     /* if the UBIDI_OPTION_REMOVE_CONTROLS option is set, and/or
    215      * marks are allowed to be inserted in one of the reordering mode, the
    216      * length of the result string may be different from the processed length.
    217      */
    218     int32_t resultLength;
    219 
    220     /* memory sizes in bytes */
    221     int32_t dirPropsSize, levelsSize, parasSize, runsSize;
    222 
    223     /* allocated memory */
    224     DirProp *dirPropsMemory;
    225     UBiDiLevel *levelsMemory;
    226     Para *parasMemory;
    227     Run *runsMemory;
    228 
    229     /* indicators for whether memory may be allocated after ubidi_open() */
    230     UBool mayAllocateText, mayAllocateRuns;
    231 
    232     /* arrays with one value per text-character */
    233     const DirProp *dirProps;
    234     UBiDiLevel *levels;
    235 
    236     /* are we performing an approximation of the "inverse BiDi" algorithm? */
    237     UBool isInverse;
    238 
    239     /* are we using the basic algorithm or its variation? */
    240     UBiDiReorderingMode reorderingMode;
    241 
    242     /* UBIDI_REORDER_xxx values must be ordered so that all the regular
    243      * logical to visual modes come first, and all inverse BiDi modes
    244      * come last.
    245      */
    246     #define UBIDI_REORDER_LAST_LOGICAL_TO_VISUAL    UBIDI_REORDER_NUMBERS_SPECIAL
    247 
    248     /* bitmask for reordering options */
    249     uint32_t reorderingOptions;
    250 
    251     /* must block separators receive level 0? */
    252     UBool orderParagraphsLTR;
    253 
    254     /* the paragraph level */
    255     UBiDiLevel paraLevel;
    256     /* original paraLevel when contextual */
    257     /* must be one of UBIDI_DEFAULT_xxx or 0 if not contextual */
    258     UBiDiLevel defaultParaLevel;
    259 
    260     /* the following is set in ubidi_setPara, used in processPropertySeq */
    261     const struct ImpTabPair * pImpTabPair;  /* pointer to levels state table pair */
    262 
    263     /* the overall paragraph or line directionality - see UBiDiDirection */
    264     UBiDiDirection direction;
    265 
    266     /* flags is a bit set for which directional properties are in the text */
    267     Flags flags;
    268 
    269     /* lastArabicPos is index to the last AL in the text, -1 if none */
    270     int32_t lastArabicPos;
    271 
    272     /* characters after trailingWSStart are WS and are */
    273     /* implicitly at the paraLevel (rule (L1)) - levels may not reflect that */
    274     int32_t trailingWSStart;
    275 
    276     /* fields for paragraph handling */
    277     int32_t paraCount;                  /* set in getDirProps() */
    278     Para *paras;                        /* limits of paragraphs, filled in
    279                             ResolveExplicitLevels() or CheckExplicitLevels() */
    280 
    281     /* for single paragraph text, we only need a tiny array of paras (no malloc()) */
    282     Para simpleParas[1];
    283 
    284     /* fields for line reordering */
    285     int32_t runCount;     /* ==-1: runs not set up yet */
    286     Run *runs;
    287 
    288     /* for non-mixed text, we only need a tiny array of runs (no malloc()) */
    289     Run simpleRuns[1];
    290 
    291     /* for inverse Bidi with insertion of directional marks */
    292     InsertPoints insertPoints;
    293 
    294     /* for option UBIDI_OPTION_REMOVE_CONTROLS */
    295     int32_t controlCount;
    296 
    297     /* for Bidi class callback */
    298     UBiDiClassCallback *fnClassCallback;    /* action pointer */
    299     const void *coClassCallback;            /* context pointer */
    300 };
    301 
    302 #define IS_VALID_PARA(x) ((x) && ((x)->pParaBiDi==(x)))
    303 #define IS_VALID_PARA_OR_LINE(x) ((x) && ((x)->pParaBiDi==(x) || (((x)->pParaBiDi) && (x)->pParaBiDi->pParaBiDi==(x)->pParaBiDi)))
    304 
    305 typedef union {
    306     DirProp *dirPropsMemory;
    307     UBiDiLevel *levelsMemory;
    308     Para *parasMemory;
    309     Run *runsMemory;
    310 } BidiMemoryForAllocation;
    311 
    312 /* Macros for initial checks at function entry */
    313 #define RETURN_IF_NULL_OR_FAILING_ERRCODE(pErrcode, retvalue)   \
    314         if((pErrcode)==NULL || U_FAILURE(*pErrcode)) return retvalue
    315 #define RETURN_IF_NOT_VALID_PARA(bidi, errcode, retvalue)   \
    316         if(!IS_VALID_PARA(bidi)) {  \
    317             errcode=U_INVALID_STATE_ERROR;  \
    318             return retvalue;                \
    319         }
    320 #define RETURN_IF_NOT_VALID_PARA_OR_LINE(bidi, errcode, retvalue)   \
    321         if(!IS_VALID_PARA_OR_LINE(bidi)) {  \
    322             errcode=U_INVALID_STATE_ERROR;  \
    323             return retvalue;                \
    324         }
    325 #define RETURN_IF_BAD_RANGE(arg, start, limit, errcode, retvalue)   \
    326         if((arg)<(start) || (arg)>=(limit)) {       \
    327             (errcode)=U_ILLEGAL_ARGUMENT_ERROR;     \
    328             return retvalue;                        \
    329         }
    330 
    331 #define RETURN_VOID_IF_NULL_OR_FAILING_ERRCODE(pErrcode)   \
    332         if((pErrcode)==NULL || U_FAILURE(*pErrcode)) return
    333 #define RETURN_VOID_IF_NOT_VALID_PARA(bidi, errcode)   \
    334         if(!IS_VALID_PARA(bidi)) {  \
    335             errcode=U_INVALID_STATE_ERROR;  \
    336             return;                \
    337         }
    338 #define RETURN_VOID_IF_NOT_VALID_PARA_OR_LINE(bidi, errcode)   \
    339         if(!IS_VALID_PARA_OR_LINE(bidi)) {  \
    340             errcode=U_INVALID_STATE_ERROR;  \
    341             return;                \
    342         }
    343 #define RETURN_VOID_IF_BAD_RANGE(arg, start, limit, errcode)   \
    344         if((arg)<(start) || (arg)>=(limit)) {       \
    345             (errcode)=U_ILLEGAL_ARGUMENT_ERROR;     \
    346             return;                        \
    347         }
    348 
    349 /* helper function to (re)allocate memory if allowed */
    350 U_CFUNC UBool
    351 ubidi_getMemory(BidiMemoryForAllocation *pMemory, int32_t *pSize, UBool mayAllocate, int32_t sizeNeeded);
    352 
    353 /* helper macros for each allocated array in UBiDi */
    354 #define getDirPropsMemory(pBiDi, length) \
    355         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->dirPropsMemory, &(pBiDi)->dirPropsSize, \
    356                         (pBiDi)->mayAllocateText, (length))
    357 
    358 #define getLevelsMemory(pBiDi, length) \
    359         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->levelsMemory, &(pBiDi)->levelsSize, \
    360                         (pBiDi)->mayAllocateText, (length))
    361 
    362 #define getRunsMemory(pBiDi, length) \
    363         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->runsMemory, &(pBiDi)->runsSize, \
    364                         (pBiDi)->mayAllocateRuns, (length)*sizeof(Run))
    365 
    366 /* additional macros used by ubidi_open() - always allow allocation */
    367 #define getInitialDirPropsMemory(pBiDi, length) \
    368         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->dirPropsMemory, &(pBiDi)->dirPropsSize, \
    369                         TRUE, (length))
    370 
    371 #define getInitialLevelsMemory(pBiDi, length) \
    372         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->levelsMemory, &(pBiDi)->levelsSize, \
    373                         TRUE, (length))
    374 
    375 #define getInitialParasMemory(pBiDi, length) \
    376         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->parasMemory, &(pBiDi)->parasSize, \
    377                         TRUE, (length)*sizeof(Para))
    378 
    379 #define getInitialRunsMemory(pBiDi, length) \
    380         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->runsMemory, &(pBiDi)->runsSize, \
    381                         TRUE, (length)*sizeof(Run))
    382 
    383 #endif
    384 
    385 #endif
    386