icuSources/i18n/rbt_set.cpp

   1 /*
   2  **********************************************************************
   3  *   Copyright (C) 1999-2008, International Business Machines
   4  *   Corporation and others.  All Rights Reserved.
   5  **********************************************************************
   6  *   Date        Name        Description
   7  *   11/17/99    aliu        Creation.
   8  **********************************************************************
   9  */
  10
  11 #include "unicode/utypes.h"
  12
  13 #if !UCONFIG_NO_TRANSLITERATION
  14
  15 #include "unicode/unistr.h"
  16 #include "unicode/uniset.h"
  17 #include "rbt_set.h"
  18 #include "rbt_rule.h"
  19 #include "cmemory.h"
  20 #include "putilimp.h"
  21
  22 U_CDECL_BEGIN
  23 static void U_CALLCONV _deleteRule(void *rule) {
  24     delete (U_NAMESPACE_QUALIFIER TransliterationRule *)rule;
  25 }
  26 U_CDECL_END
  27
  28 //----------------------------------------------------------------------
  29 // BEGIN Debugging support
  30 //----------------------------------------------------------------------
  31
  32 // #define DEBUG_RBT
  33
  34 #ifdef DEBUG_RBT
  35 #include <stdio.h>
  36 #include "charstr.h"
  37
  38 /**
  39  * @param appendTo result is appended to this param.
  40  * @param input the string being transliterated
  41  * @param pos the index struct
  42  */
  43 static UnicodeString& _formatInput(UnicodeString &appendTo,
  44                                    const UnicodeString& input,
  45                                    const UTransPosition& pos) {
  46     // Output a string of the form aaa{bbb|ccc|ddd}eee, where
  47     // the {} indicate the context start and limit, and the ||
  48     // indicate the start and limit.
  49     if (0 <= pos.contextStart &&
  50         pos.contextStart <= pos.start &&
  51         pos.start <= pos.limit &&
  52         pos.limit <= pos.contextLimit &&
  53         pos.contextLimit <= input.length()) {
  54
  55         UnicodeString a, b, c, d, e;
  56         input.extractBetween(0, pos.contextStart, a);
  57         input.extractBetween(pos.contextStart, pos.start, b);
  58         input.extractBetween(pos.start, pos.limit, c);
  59         input.extractBetween(pos.limit, pos.contextLimit, d);
  60         input.extractBetween(pos.contextLimit, input.length(), e);
  61         appendTo.append(a).append((UChar)123/*{*/).append(b).
  62             append((UChar)124/*|*/).append(c).append((UChar)124/*|*/).append(d).
  63             append((UChar)125/*}*/).append(e);
  64     } else {
  65         appendTo.append("INVALID UTransPosition");
  66         //appendTo.append((UnicodeString)"INVALID UTransPosition {cs=" +
  67         //                pos.contextStart + ", s=" + pos.start + ", l=" +
  68         //                pos.limit + ", cl=" + pos.contextLimit + "} on " +
  69         //                input);
  70     }
  71     return appendTo;
  72 }
  73
  74 // Append a hex string to the target
  75 UnicodeString& _appendHex(uint32_t number,
  76                           int32_t digits,
  77                           UnicodeString& target) {
  78     static const UChar digitString[] = {
  79         0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
  80         0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0
  81     };
  82     while (digits--) {
  83         target += digitString[(number >> (digits*4)) & 0xF];
  84     }
  85     return target;
  86 }
  87
  88 // Replace nonprintable characters with unicode escapes
  89 UnicodeString& _escape(const UnicodeString &source,
  90                        UnicodeString &target) {
  91     for (int32_t i = 0; i < source.length(); ) {
  92         UChar32 ch = source.char32At(i);
  93         i += UTF_CHAR_LENGTH(ch);
  94         if (ch < 0x09 || (ch > 0x0A && ch < 0x20)|| ch > 0x7E) {
  95             if (ch <= 0xFFFF) {
  96                 target += "\\u";
  97                 _appendHex(ch, 4, target);
  98             } else {
  99                 target += "\\U";
 100                 _appendHex(ch, 8, target);
 101             }
 102         } else {
 103             target += ch;
 104         }
 105     }
 106     return target;
 107 }
 108
 109 inline void _debugOut(const char* msg, TransliterationRule* rule,
 110                       const Replaceable& theText, UTransPosition& pos) {
 111     UnicodeString buf(msg, "");
 112     if (rule) {
 113         UnicodeString r;
 114         rule->toRule(r, TRUE);
 115         buf.append((UChar)32).append(r);
 116     }
 117     buf.append(UnicodeString(" => ", ""));
 118     UnicodeString* text = (UnicodeString*)&theText;
 119     _formatInput(buf, *text, pos);
 120     UnicodeString esc;
 121     _escape(buf, esc);
 122     CharString cbuf(esc);
 123     printf("%s\n", (const char*) cbuf);
 124 }
 125
 126 #else
 127 #define _debugOut(msg, rule, theText, pos)
 128 #endif
 129
 130 //----------------------------------------------------------------------
 131 // END Debugging support
 132 //----------------------------------------------------------------------
 133
 134 // Fill the precontext and postcontext with the patterns of the rules
 135 // that are masking one another.
 136 static void maskingError(const U_NAMESPACE_QUALIFIER TransliterationRule& rule1,
 137                          const U_NAMESPACE_QUALIFIER TransliterationRule& rule2,
 138                          UParseError& parseError) {
 139     U_NAMESPACE_QUALIFIER UnicodeString r;
 140     int32_t len;
 141
 142     parseError.line = parseError.offset = -1;
 143
 144     // for pre-context
 145     rule1.toRule(r, FALSE);
 146     len = uprv_min(r.length(), U_PARSE_CONTEXT_LEN-1);
 147     r.extract(0, len, parseError.preContext);
 148     parseError.preContext[len] = 0;
 149
 150     //for post-context
 151     r.truncate(0);
 152     rule2.toRule(r, FALSE);
 153     len = uprv_min(r.length(), U_PARSE_CONTEXT_LEN-1);
 154     r.extract(0, len, parseError.postContext);
 155     parseError.postContext[len] = 0;
 156 }
 157
 158 U_NAMESPACE_BEGIN
 159
 160 /**
 161  * Construct a new empty rule set.
 162  */
 163 TransliterationRuleSet::TransliterationRuleSet(UErrorCode& status) : UMemory() {
 164     ruleVector = new UVector(&_deleteRule, NULL, status);
 165     if (U_FAILURE(status)) {
 166         return;
 167     }
 168     if (ruleVector == NULL) {
 169         status = U_MEMORY_ALLOCATION_ERROR;
 170     }
 171     rules = NULL;
 172     maxContextLength = 0;
 173 }
 174
 175 /**
 176  * Copy constructor.
 177  */
 178 TransliterationRuleSet::TransliterationRuleSet(const TransliterationRuleSet& other) :
 179     UMemory(other),
 180     ruleVector(0),
 181     rules(0),
 182     maxContextLength(other.maxContextLength) {
 183
 184     int32_t i, len;
 185     uprv_memcpy(index, other.index, sizeof(index));
 186     UErrorCode status = U_ZERO_ERROR;
 187     ruleVector = new UVector(&_deleteRule, NULL, status);
 188     if (other.ruleVector != 0 && ruleVector != 0 && U_SUCCESS(status)) {
 189         len = other.ruleVector->size();
 190         for (i=0; i<len && U_SUCCESS(status); ++i) {
 191             TransliterationRule *tempTranslitRule = new TransliterationRule(*(TransliterationRule*)other.ruleVector->elementAt(i));
 192             // Null pointer test
 193             if (tempTranslitRule == NULL) {
 194                 status = U_MEMORY_ALLOCATION_ERROR;
 195                 break;
 196             }
 197             ruleVector->addElement(tempTranslitRule, status);
 198             if (U_FAILURE(status)) {
 199                 break;
 200             }
 201         }
 202     }
 203     if (other.rules != 0 && U_SUCCESS(status)) {
 204         UParseError p;
 205         freeze(p, status);
 206     }
 207 }
 208
 209 /**
 210  * Destructor.
 211  */
 212 TransliterationRuleSet::~TransliterationRuleSet() {
 213     delete ruleVector; // This deletes the contained rules
 214     uprv_free(rules);
 215 }
 216
 217 void TransliterationRuleSet::setData(const TransliterationRuleData* d) {
 218     /**
 219      * We assume that the ruleset has already been frozen.
 220      */
 221     int32_t len = index[256]; // see freeze()
 222     for (int32_t i=0; i<len; ++i) {
 223         rules[i]->setData(d);
 224     }
 225 }
 226
 227 /**
 228  * Return the maximum context length.
 229  * @return the length of the longest preceding context.
 230  */
 231 int32_t TransliterationRuleSet::getMaximumContextLength(void) const {
 232     return maxContextLength;
 233 }
 234
 235 /**
 236  * Add a rule to this set.  Rules are added in order, and order is
 237  * significant.  The last call to this method must be followed by
 238  * a call to <code>freeze()</code> before the rule set is used.
 239  *
 240  * <p>If freeze() has already been called, calling addRule()
 241  * unfreezes the rules, and freeze() must be called again.
 242  *
 243  * @param adoptedRule the rule to add
 244  */
 245 void TransliterationRuleSet::addRule(TransliterationRule* adoptedRule,
 246                                      UErrorCode& status) {
 247     if (U_FAILURE(status)) {
 248         delete adoptedRule;
 249         return;
 250     }
 251     ruleVector->addElement(adoptedRule, status);
 252
 253     int32_t len;
 254     if ((len = adoptedRule->getContextLength()) > maxContextLength) {
 255         maxContextLength = len;
 256     }
 257
 258     uprv_free(rules);
 259     rules = 0;
 260 }
 261
 262 /**
 263  * Check this for masked rules and index it to optimize performance.
 264  * The sequence of operations is: (1) add rules to a set using
 265  * <code>addRule()</code>; (2) freeze the set using
 266  * <code>freeze()</code>; (3) use the rule set.  If
 267  * <code>addRule()</code> is called after calling this method, it
 268  * invalidates this object, and this method must be called again.
 269  * That is, <code>freeze()</code> may be called multiple times,
 270  * although for optimal performance it shouldn't be.
 271  */
 272 void TransliterationRuleSet::freeze(UParseError& parseError,UErrorCode& status) {
 273     /* Construct the rule array and index table.  We reorder the
 274      * rules by sorting them into 256 bins.  Each bin contains all
 275      * rules matching the index value for that bin.  A rule
 276      * matches an index value if string whose first key character
 277      * has a low byte equal to the index value can match the rule.
 278      *
 279      * Each bin contains zero or more rules, in the same order
 280      * they were found originally.  However, the total rules in
 281      * the bins may exceed the number in the original vector,
 282      * since rules that have a variable as their first key
 283      * character will generally fall into more than one bin.
 284      *
 285      * That is, each bin contains all rules that either have that
 286      * first index value as their first key character, or have
 287      * a set containing the index value as their first character.
 288      */
 289     int32_t n = ruleVector->size();
 290     int32_t j;
 291     int16_t x;
 292     UVector v(2*n, status); // heuristic; adjust as needed
 293
 294     if (U_FAILURE(status)) {
 295         return;
 296     }
 297
 298     /* Precompute the index values.  This saves a LOT of time.
 299      * Be careful not to call malloc(0).
 300      */
 301     int16_t* indexValue = (int16_t*) uprv_malloc( sizeof(int16_t) * (n > 0 ? n : 1) );
 302     /* test for NULL */
 303     if (indexValue == 0) {
 304         status = U_MEMORY_ALLOCATION_ERROR;
 305         return;
 306     }
 307     for (j=0; j<n; ++j) {
 308         TransliterationRule* r = (TransliterationRule*) ruleVector->elementAt(j);
 309         indexValue[j] = r->getIndexValue();
 310     }
 311     for (x=0; x<256; ++x) {
 312         index[x] = v.size();
 313         for (j=0; j<n; ++j) {
 314             if (indexValue[j] >= 0) {
 315                 if (indexValue[j] == x) {
 316                     v.addElement(ruleVector->elementAt(j), status);
 317                 }
 318             } else {
 319                 // If the indexValue is < 0, then the first key character is
 320                 // a set, and we must use the more time-consuming
 321                 // matchesIndexValue check.  In practice this happens
 322                 // rarely, so we seldom tread this code path.
 323                 TransliterationRule* r = (TransliterationRule*) ruleVector->elementAt(j);
 324                 if (r->matchesIndexValue((uint8_t)x)) {
 325                     v.addElement(r, status);
 326                 }
 327             }
 328         }
 329     }
 330     uprv_free(indexValue);
 331     index[256] = v.size();
 332
 333     /* Freeze things into an array.
 334      */
 335     uprv_free(rules); // Contains alias pointers
 336
 337     /* You can't do malloc(0)! */
 338     if (v.size() == 0) {
 339         rules = NULL;
 340         return;
 341     }
 342     rules = (TransliterationRule **)uprv_malloc(v.size() * sizeof(TransliterationRule *));
 343     /* test for NULL */
 344     if (rules == 0) {
 345         status = U_MEMORY_ALLOCATION_ERROR;
 346         return;
 347     }
 348     for (j=0; j<v.size(); ++j) {
 349         rules[j] = (TransliterationRule*) v.elementAt(j);
 350     }
 351
 352     // TODO Add error reporting that indicates the rules that
 353     //      are being masked.
 354     //UnicodeString errors;
 355
 356     /* Check for masking.  This is MUCH faster than our old check,
 357      * which was each rule against each following rule, since we
 358      * only have to check for masking within each bin now.  It's
 359      * 256*O(n2^2) instead of O(n1^2), where n1 is the total rule
 360      * count, and n2 is the per-bin rule count.  But n2<<n1, so
 361      * it's a big win.
 362      */
 363     for (x=0; x<256; ++x) {
 364         for (j=index[x]; j<index[x+1]-1; ++j) {
 365             TransliterationRule* r1 = rules[j];
 366             for (int32_t k=j+1; k<index[x+1]; ++k) {
 367                 TransliterationRule* r2 = rules[k];
 368                 if (r1->masks(*r2)) {
 369 //|                 if (errors == null) {
 370 //|                     errors = new StringBuffer();
 371 //|                 } else {
 372 //|                     errors.append("\n");
 373 //|                 }
 374 //|                 errors.append("Rule " + r1 + " masks " + r2);
 375                     status = U_RULE_MASK_ERROR;
 376                     maskingError(*r1, *r2, parseError);
 377                     return;
 378                 }
 379             }
 380         }
 381     }
 382
 383     //if (errors != null) {
 384     //    throw new IllegalArgumentException(errors.toString());
 385     //}
 386 }
 387
 388 /**
 389  * Transliterate the given text with the given UTransPosition
 390  * indices.  Return TRUE if the transliteration should continue
 391  * or FALSE if it should halt (because of a U_PARTIAL_MATCH match).
 392  * Note that FALSE is only ever returned if isIncremental is TRUE.
 393  * @param text the text to be transliterated
 394  * @param pos the position indices, which will be updated
 395  * @param incremental if TRUE, assume new text may be inserted
 396  * at index.limit, and return FALSE if thre is a partial match.
 397  * @return TRUE unless a U_PARTIAL_MATCH has been obtained,
 398  * indicating that transliteration should stop until more text
 399  * arrives.
 400  */
 401 UBool TransliterationRuleSet::transliterate(Replaceable& text,
 402                                             UTransPosition& pos,
 403                                             UBool incremental) {
 404     int16_t indexByte = (int16_t) (text.char32At(pos.start) & 0xFF);
 405     for (int32_t i=index[indexByte]; i<index[indexByte+1]; ++i) {
 406         UMatchDegree m = rules[i]->matchAndReplace(text, pos, incremental);
 407         switch (m) {
 408         case U_MATCH:
 409             _debugOut("match", rules[i], text, pos);
 410             return TRUE;
 411         case U_PARTIAL_MATCH:
 412             _debugOut("partial match", rules[i], text, pos);
 413             return FALSE;
 414         default: /* Ram: added default to make GCC happy */
 415             break;
 416         }
 417     }
 418     // No match or partial match from any rule
 419     pos.start += UTF_CHAR_LENGTH(text.char32At(pos.start));
 420     _debugOut("no match", NULL, text, pos);
 421     return TRUE;
 422 }
 423
 424 /**
 425  * Create rule strings that represents this rule set.
 426  */
 427 UnicodeString& TransliterationRuleSet::toRules(UnicodeString& ruleSource,
 428                                                UBool escapeUnprintable) const {
 429     int32_t i;
 430     int32_t count = ruleVector->size();
 431     ruleSource.truncate(0);
 432     for (i=0; i<count; ++i) {
 433         if (i != 0) {
 434             ruleSource.append((UChar) 0x000A /*\n*/);
 435         }
 436         TransliterationRule *r =
 437             (TransliterationRule*) ruleVector->elementAt(i);
 438         r->toRule(ruleSource, escapeUnprintable);
 439     }
 440     return ruleSource;
 441 }
 442
 443 /**
 444  * Return the set of all characters that may be modified
 445  * (getTarget=false) or emitted (getTarget=true) by this set.
 446  */
 447 UnicodeSet& TransliterationRuleSet::getSourceTargetSet(UnicodeSet& result,
 448                                UBool getTarget) const
 449 {
 450     result.clear();
 451     int32_t count = ruleVector->size();
 452     for (int32_t i=0; i<count; ++i) {
 453         TransliterationRule* r =
 454             (TransliterationRule*) ruleVector->elementAt(i);
 455         if (getTarget) {
 456             r->addTargetSetTo(result);
 457         } else {
 458             r->addSourceSetTo(result);
 459         }
 460     }
 461     return result;
 462 }
 463
 464 U_NAMESPACE_END
 465
 466 #endif /* #if !UCONFIG_NO_TRANSLITERATION */