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1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4  **********************************************************************
5  *   Copyright (C) 1999-2011, International Business Machines
6  *   Corporation and others.  All Rights Reserved.
7  **********************************************************************
8  *   Date        Name        Description
9  *   11/17/99    aliu        Creation.
10  **********************************************************************
11  */
12 
13 #include "unicode/utypes.h"
14 
15 #if !UCONFIG_NO_TRANSLITERATION
16 
17 #include "unicode/unistr.h"
18 #include "unicode/uniset.h"
19 #include "unicode/utf16.h"
20 #include "rbt_set.h"
21 #include "rbt_rule.h"
22 #include "cmemory.h"
23 #include "putilimp.h"
24 
25 U_CDECL_BEGIN
_deleteRule(void * rule)26 static void U_CALLCONV _deleteRule(void *rule) {
27     delete (icu::TransliterationRule *)rule;
28 }
29 U_CDECL_END
30 
31 //----------------------------------------------------------------------
32 // BEGIN Debugging support
33 //----------------------------------------------------------------------
34 
35 // #define DEBUG_RBT
36 
37 #ifdef DEBUG_RBT
38 #include <stdio.h>
39 #include "charstr.h"
40 
41 /**
42  * @param appendTo result is appended to this param.
43  * @param input the string being transliterated
44  * @param pos the index struct
45  */
_formatInput(UnicodeString & appendTo,const UnicodeString & input,const UTransPosition & pos)46 static UnicodeString& _formatInput(UnicodeString &appendTo,
47                                    const UnicodeString& input,
48                                    const UTransPosition& pos) {
49     // Output a string of the form aaa{bbb|ccc|ddd}eee, where
50     // the {} indicate the context start and limit, and the ||
51     // indicate the start and limit.
52     if (0 <= pos.contextStart &&
53         pos.contextStart <= pos.start &&
54         pos.start <= pos.limit &&
55         pos.limit <= pos.contextLimit &&
56         pos.contextLimit <= input.length()) {
57 
58         UnicodeString a, b, c, d, e;
59         input.extractBetween(0, pos.contextStart, a);
60         input.extractBetween(pos.contextStart, pos.start, b);
61         input.extractBetween(pos.start, pos.limit, c);
62         input.extractBetween(pos.limit, pos.contextLimit, d);
63         input.extractBetween(pos.contextLimit, input.length(), e);
64         appendTo.append(a).append((UChar)123/*{*/).append(b).
65             append((UChar)124/*|*/).append(c).append((UChar)124/*|*/).append(d).
66             append((UChar)125/*}*/).append(e);
67     } else {
68         appendTo.append("INVALID UTransPosition");
69         //appendTo.append((UnicodeString)"INVALID UTransPosition {cs=" +
70         //                pos.contextStart + ", s=" + pos.start + ", l=" +
71         //                pos.limit + ", cl=" + pos.contextLimit + "} on " +
72         //                input);
73     }
74     return appendTo;
75 }
76 
77 // Append a hex string to the target
_appendHex(uint32_t number,int32_t digits,UnicodeString & target)78 UnicodeString& _appendHex(uint32_t number,
79                           int32_t digits,
80                           UnicodeString& target) {
81     static const UChar digitString[] = {
82         0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
83         0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0
84     };
85     while (digits--) {
86         target += digitString[(number >> (digits*4)) & 0xF];
87     }
88     return target;
89 }
90 
91 // Replace nonprintable characters with unicode escapes
_escape(const UnicodeString & source,UnicodeString & target)92 UnicodeString& _escape(const UnicodeString &source,
93                        UnicodeString &target) {
94     for (int32_t i = 0; i < source.length(); ) {
95         UChar32 ch = source.char32At(i);
96         i += U16_LENGTH(ch);
97         if (ch < 0x09 || (ch > 0x0A && ch < 0x20)|| ch > 0x7E) {
98             if (ch <= 0xFFFF) {
99                 target += "\\u";
100                 _appendHex(ch, 4, target);
101             } else {
102                 target += "\\U";
103                 _appendHex(ch, 8, target);
104             }
105         } else {
106             target += ch;
107         }
108     }
109     return target;
110 }
111 
_debugOut(const char * msg,TransliterationRule * rule,const Replaceable & theText,UTransPosition & pos)112 inline void _debugOut(const char* msg, TransliterationRule* rule,
113                       const Replaceable& theText, UTransPosition& pos) {
114     UnicodeString buf(msg, "");
115     if (rule) {
116         UnicodeString r;
117         rule->toRule(r, TRUE);
118         buf.append((UChar)32).append(r);
119     }
120     buf.append(UnicodeString(" => ", ""));
121     UnicodeString* text = (UnicodeString*)&theText;
122     _formatInput(buf, *text, pos);
123     UnicodeString esc;
124     _escape(buf, esc);
125     CharString cbuf(esc);
126     printf("%s\n", (const char*) cbuf);
127 }
128 
129 #else
130 #define _debugOut(msg, rule, theText, pos)
131 #endif
132 
133 //----------------------------------------------------------------------
134 // END Debugging support
135 //----------------------------------------------------------------------
136 
137 // Fill the precontext and postcontext with the patterns of the rules
138 // that are masking one another.
maskingError(const icu::TransliterationRule & rule1,const icu::TransliterationRule & rule2,UParseError & parseError)139 static void maskingError(const icu::TransliterationRule& rule1,
140                          const icu::TransliterationRule& rule2,
141                          UParseError& parseError) {
142     icu::UnicodeString r;
143     int32_t len;
144 
145     parseError.line = parseError.offset = -1;
146 
147     // for pre-context
148     rule1.toRule(r, FALSE);
149     len = uprv_min(r.length(), U_PARSE_CONTEXT_LEN-1);
150     r.extract(0, len, parseError.preContext);
151     parseError.preContext[len] = 0;
152 
153     //for post-context
154     r.truncate(0);
155     rule2.toRule(r, FALSE);
156     len = uprv_min(r.length(), U_PARSE_CONTEXT_LEN-1);
157     r.extract(0, len, parseError.postContext);
158     parseError.postContext[len] = 0;
159 }
160 
161 U_NAMESPACE_BEGIN
162 
163 /**
164  * Construct a new empty rule set.
165  */
TransliterationRuleSet(UErrorCode & status)166 TransliterationRuleSet::TransliterationRuleSet(UErrorCode& status) : UMemory() {
167     ruleVector = new UVector(&_deleteRule, NULL, status);
168     if (U_FAILURE(status)) {
169         return;
170     }
171     if (ruleVector == NULL) {
172         status = U_MEMORY_ALLOCATION_ERROR;
173     }
174     rules = NULL;
175     maxContextLength = 0;
176 }
177 
178 /**
179  * Copy constructor.
180  */
TransliterationRuleSet(const TransliterationRuleSet & other)181 TransliterationRuleSet::TransliterationRuleSet(const TransliterationRuleSet& other) :
182     UMemory(other),
183     ruleVector(0),
184     rules(0),
185     maxContextLength(other.maxContextLength) {
186 
187     int32_t i, len;
188     uprv_memcpy(index, other.index, sizeof(index));
189     UErrorCode status = U_ZERO_ERROR;
190     ruleVector = new UVector(&_deleteRule, NULL, status);
191     if (other.ruleVector != 0 && ruleVector != 0 && U_SUCCESS(status)) {
192         len = other.ruleVector->size();
193         for (i=0; i<len && U_SUCCESS(status); ++i) {
194             TransliterationRule *tempTranslitRule = new TransliterationRule(*(TransliterationRule*)other.ruleVector->elementAt(i));
195             // Null pointer test
196             if (tempTranslitRule == NULL) {
197                 status = U_MEMORY_ALLOCATION_ERROR;
198                 break;
199             }
200             ruleVector->addElement(tempTranslitRule, status);
201             if (U_FAILURE(status)) {
202                 break;
203             }
204         }
205     }
206     if (other.rules != 0 && U_SUCCESS(status)) {
207         UParseError p;
208         freeze(p, status);
209     }
210 }
211 
212 /**
213  * Destructor.
214  */
~TransliterationRuleSet()215 TransliterationRuleSet::~TransliterationRuleSet() {
216     delete ruleVector; // This deletes the contained rules
217     uprv_free(rules);
218 }
219 
setData(const TransliterationRuleData * d)220 void TransliterationRuleSet::setData(const TransliterationRuleData* d) {
221     /**
222      * We assume that the ruleset has already been frozen.
223      */
224     int32_t len = index[256]; // see freeze()
225     for (int32_t i=0; i<len; ++i) {
226         rules[i]->setData(d);
227     }
228 }
229 
230 /**
231  * Return the maximum context length.
232  * @return the length of the longest preceding context.
233  */
getMaximumContextLength(void) const234 int32_t TransliterationRuleSet::getMaximumContextLength(void) const {
235     return maxContextLength;
236 }
237 
238 /**
239  * Add a rule to this set.  Rules are added in order, and order is
240  * significant.  The last call to this method must be followed by
241  * a call to <code>freeze()</code> before the rule set is used.
242  *
243  * <p>If freeze() has already been called, calling addRule()
244  * unfreezes the rules, and freeze() must be called again.
245  *
246  * @param adoptedRule the rule to add
247  */
addRule(TransliterationRule * adoptedRule,UErrorCode & status)248 void TransliterationRuleSet::addRule(TransliterationRule* adoptedRule,
249                                      UErrorCode& status) {
250     if (U_FAILURE(status)) {
251         delete adoptedRule;
252         return;
253     }
254     ruleVector->addElement(adoptedRule, status);
255 
256     int32_t len;
257     if ((len = adoptedRule->getContextLength()) > maxContextLength) {
258         maxContextLength = len;
259     }
260 
261     uprv_free(rules);
262     rules = 0;
263 }
264 
265 /**
266  * Check this for masked rules and index it to optimize performance.
267  * The sequence of operations is: (1) add rules to a set using
268  * <code>addRule()</code>; (2) freeze the set using
269  * <code>freeze()</code>; (3) use the rule set.  If
270  * <code>addRule()</code> is called after calling this method, it
271  * invalidates this object, and this method must be called again.
272  * That is, <code>freeze()</code> may be called multiple times,
273  * although for optimal performance it shouldn't be.
274  */
freeze(UParseError & parseError,UErrorCode & status)275 void TransliterationRuleSet::freeze(UParseError& parseError,UErrorCode& status) {
276     /* Construct the rule array and index table.  We reorder the
277      * rules by sorting them into 256 bins.  Each bin contains all
278      * rules matching the index value for that bin.  A rule
279      * matches an index value if string whose first key character
280      * has a low byte equal to the index value can match the rule.
281      *
282      * Each bin contains zero or more rules, in the same order
283      * they were found originally.  However, the total rules in
284      * the bins may exceed the number in the original vector,
285      * since rules that have a variable as their first key
286      * character will generally fall into more than one bin.
287      *
288      * That is, each bin contains all rules that either have that
289      * first index value as their first key character, or have
290      * a set containing the index value as their first character.
291      */
292     int32_t n = ruleVector->size();
293     int32_t j;
294     int16_t x;
295     UVector v(2*n, status); // heuristic; adjust as needed
296 
297     if (U_FAILURE(status)) {
298         return;
299     }
300 
301     /* Precompute the index values.  This saves a LOT of time.
302      * Be careful not to call malloc(0).
303      */
304     int16_t* indexValue = (int16_t*) uprv_malloc( sizeof(int16_t) * (n > 0 ? n : 1) );
305     /* test for NULL */
306     if (indexValue == 0) {
307         status = U_MEMORY_ALLOCATION_ERROR;
308         return;
309     }
310     for (j=0; j<n; ++j) {
311         TransliterationRule* r = (TransliterationRule*) ruleVector->elementAt(j);
312         indexValue[j] = r->getIndexValue();
313     }
314     for (x=0; x<256; ++x) {
315         index[x] = v.size();
316         for (j=0; j<n; ++j) {
317             if (indexValue[j] >= 0) {
318                 if (indexValue[j] == x) {
319                     v.addElement(ruleVector->elementAt(j), status);
320                 }
321             } else {
322                 // If the indexValue is < 0, then the first key character is
323                 // a set, and we must use the more time-consuming
324                 // matchesIndexValue check.  In practice this happens
325                 // rarely, so we seldom tread this code path.
326                 TransliterationRule* r = (TransliterationRule*) ruleVector->elementAt(j);
327                 if (r->matchesIndexValue((uint8_t)x)) {
328                     v.addElement(r, status);
329                 }
330             }
331         }
332     }
333     uprv_free(indexValue);
334     index[256] = v.size();
335 
336     /* Freeze things into an array.
337      */
338     uprv_free(rules); // Contains alias pointers
339 
340     /* You can't do malloc(0)! */
341     if (v.size() == 0) {
342         rules = NULL;
343         return;
344     }
345     rules = (TransliterationRule **)uprv_malloc(v.size() * sizeof(TransliterationRule *));
346     /* test for NULL */
347     if (rules == 0) {
348         status = U_MEMORY_ALLOCATION_ERROR;
349         return;
350     }
351     for (j=0; j<v.size(); ++j) {
352         rules[j] = (TransliterationRule*) v.elementAt(j);
353     }
354 
355     // TODO Add error reporting that indicates the rules that
356     //      are being masked.
357     //UnicodeString errors;
358 
359     /* Check for masking.  This is MUCH faster than our old check,
360      * which was each rule against each following rule, since we
361      * only have to check for masking within each bin now.  It's
362      * 256*O(n2^2) instead of O(n1^2), where n1 is the total rule
363      * count, and n2 is the per-bin rule count.  But n2<<n1, so
364      * it's a big win.
365      */
366     for (x=0; x<256; ++x) {
367         for (j=index[x]; j<index[x+1]-1; ++j) {
368             TransliterationRule* r1 = rules[j];
369             for (int32_t k=j+1; k<index[x+1]; ++k) {
370                 TransliterationRule* r2 = rules[k];
371                 if (r1->masks(*r2)) {
372 //|                 if (errors == null) {
373 //|                     errors = new StringBuffer();
374 //|                 } else {
375 //|                     errors.append("\n");
376 //|                 }
377 //|                 errors.append("Rule " + r1 + " masks " + r2);
378                     status = U_RULE_MASK_ERROR;
379                     maskingError(*r1, *r2, parseError);
380                     return;
381                 }
382             }
383         }
384     }
385 
386     //if (errors != null) {
387     //    throw new IllegalArgumentException(errors.toString());
388     //}
389 }
390 
391 /**
392  * Transliterate the given text with the given UTransPosition
393  * indices.  Return TRUE if the transliteration should continue
394  * or FALSE if it should halt (because of a U_PARTIAL_MATCH match).
395  * Note that FALSE is only ever returned if isIncremental is TRUE.
396  * @param text the text to be transliterated
397  * @param pos the position indices, which will be updated
398  * @param incremental if TRUE, assume new text may be inserted
399  * at index.limit, and return FALSE if thre is a partial match.
400  * @return TRUE unless a U_PARTIAL_MATCH has been obtained,
401  * indicating that transliteration should stop until more text
402  * arrives.
403  */
transliterate(Replaceable & text,UTransPosition & pos,UBool incremental)404 UBool TransliterationRuleSet::transliterate(Replaceable& text,
405                                             UTransPosition& pos,
406                                             UBool incremental) {
407     int16_t indexByte = (int16_t) (text.char32At(pos.start) & 0xFF);
408     for (int32_t i=index[indexByte]; i<index[indexByte+1]; ++i) {
409         UMatchDegree m = rules[i]->matchAndReplace(text, pos, incremental);
410         switch (m) {
411         case U_MATCH:
412             _debugOut("match", rules[i], text, pos);
413             return TRUE;
414         case U_PARTIAL_MATCH:
415             _debugOut("partial match", rules[i], text, pos);
416             return FALSE;
417         default: /* Ram: added default to make GCC happy */
418             break;
419         }
420     }
421     // No match or partial match from any rule
422     pos.start += U16_LENGTH(text.char32At(pos.start));
423     _debugOut("no match", NULL, text, pos);
424     return TRUE;
425 }
426 
427 /**
428  * Create rule strings that represents this rule set.
429  */
toRules(UnicodeString & ruleSource,UBool escapeUnprintable) const430 UnicodeString& TransliterationRuleSet::toRules(UnicodeString& ruleSource,
431                                                UBool escapeUnprintable) const {
432     int32_t i;
433     int32_t count = ruleVector->size();
434     ruleSource.truncate(0);
435     for (i=0; i<count; ++i) {
436         if (i != 0) {
437             ruleSource.append((UChar) 0x000A /*\n*/);
438         }
439         TransliterationRule *r =
440             (TransliterationRule*) ruleVector->elementAt(i);
441         r->toRule(ruleSource, escapeUnprintable);
442     }
443     return ruleSource;
444 }
445 
446 /**
447  * Return the set of all characters that may be modified
448  * (getTarget=false) or emitted (getTarget=true) by this set.
449  */
getSourceTargetSet(UnicodeSet & result,UBool getTarget) const450 UnicodeSet& TransliterationRuleSet::getSourceTargetSet(UnicodeSet& result,
451                                UBool getTarget) const
452 {
453     result.clear();
454     int32_t count = ruleVector->size();
455     for (int32_t i=0; i<count; ++i) {
456         TransliterationRule* r =
457             (TransliterationRule*) ruleVector->elementAt(i);
458         if (getTarget) {
459             r->addTargetSetTo(result);
460         } else {
461             r->addSourceSetTo(result);
462         }
463     }
464     return result;
465 }
466 
467 U_NAMESPACE_END
468 
469 #endif /* #if !UCONFIG_NO_TRANSLITERATION */
470