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1 /*
2  **********************************************************************
3  *   Copyright (C) 1999-2011, 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 "unicode/utf16.h"
18 #include "rbt_set.h"
19 #include "rbt_rule.h"
20 #include "cmemory.h"
21 #include "putilimp.h"
22 
23 U_CDECL_BEGIN
_deleteRule(void * rule)24 static void U_CALLCONV _deleteRule(void *rule) {
25     delete (icu::TransliterationRule *)rule;
26 }
27 U_CDECL_END
28 
29 //----------------------------------------------------------------------
30 // BEGIN Debugging support
31 //----------------------------------------------------------------------
32 
33 // #define DEBUG_RBT
34 
35 #ifdef DEBUG_RBT
36 #include <stdio.h>
37 #include "charstr.h"
38 
39 /**
40  * @param appendTo result is appended to this param.
41  * @param input the string being transliterated
42  * @param pos the index struct
43  */
_formatInput(UnicodeString & appendTo,const UnicodeString & input,const UTransPosition & pos)44 static UnicodeString& _formatInput(UnicodeString &appendTo,
45                                    const UnicodeString& input,
46                                    const UTransPosition& pos) {
47     // Output a string of the form aaa{bbb|ccc|ddd}eee, where
48     // the {} indicate the context start and limit, and the ||
49     // indicate the start and limit.
50     if (0 <= pos.contextStart &&
51         pos.contextStart <= pos.start &&
52         pos.start <= pos.limit &&
53         pos.limit <= pos.contextLimit &&
54         pos.contextLimit <= input.length()) {
55 
56         UnicodeString a, b, c, d, e;
57         input.extractBetween(0, pos.contextStart, a);
58         input.extractBetween(pos.contextStart, pos.start, b);
59         input.extractBetween(pos.start, pos.limit, c);
60         input.extractBetween(pos.limit, pos.contextLimit, d);
61         input.extractBetween(pos.contextLimit, input.length(), e);
62         appendTo.append(a).append((UChar)123/*{*/).append(b).
63             append((UChar)124/*|*/).append(c).append((UChar)124/*|*/).append(d).
64             append((UChar)125/*}*/).append(e);
65     } else {
66         appendTo.append("INVALID UTransPosition");
67         //appendTo.append((UnicodeString)"INVALID UTransPosition {cs=" +
68         //                pos.contextStart + ", s=" + pos.start + ", l=" +
69         //                pos.limit + ", cl=" + pos.contextLimit + "} on " +
70         //                input);
71     }
72     return appendTo;
73 }
74 
75 // Append a hex string to the target
_appendHex(uint32_t number,int32_t digits,UnicodeString & target)76 UnicodeString& _appendHex(uint32_t number,
77                           int32_t digits,
78                           UnicodeString& target) {
79     static const UChar digitString[] = {
80         0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
81         0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0
82     };
83     while (digits--) {
84         target += digitString[(number >> (digits*4)) & 0xF];
85     }
86     return target;
87 }
88 
89 // Replace nonprintable characters with unicode escapes
_escape(const UnicodeString & source,UnicodeString & target)90 UnicodeString& _escape(const UnicodeString &source,
91                        UnicodeString &target) {
92     for (int32_t i = 0; i < source.length(); ) {
93         UChar32 ch = source.char32At(i);
94         i += U16_LENGTH(ch);
95         if (ch < 0x09 || (ch > 0x0A && ch < 0x20)|| ch > 0x7E) {
96             if (ch <= 0xFFFF) {
97                 target += "\\u";
98                 _appendHex(ch, 4, target);
99             } else {
100                 target += "\\U";
101                 _appendHex(ch, 8, target);
102             }
103         } else {
104             target += ch;
105         }
106     }
107     return target;
108 }
109 
_debugOut(const char * msg,TransliterationRule * rule,const Replaceable & theText,UTransPosition & pos)110 inline void _debugOut(const char* msg, TransliterationRule* rule,
111                       const Replaceable& theText, UTransPosition& pos) {
112     UnicodeString buf(msg, "");
113     if (rule) {
114         UnicodeString r;
115         rule->toRule(r, TRUE);
116         buf.append((UChar)32).append(r);
117     }
118     buf.append(UnicodeString(" => ", ""));
119     UnicodeString* text = (UnicodeString*)&theText;
120     _formatInput(buf, *text, pos);
121     UnicodeString esc;
122     _escape(buf, esc);
123     CharString cbuf(esc);
124     printf("%s\n", (const char*) cbuf);
125 }
126 
127 #else
128 #define _debugOut(msg, rule, theText, pos)
129 #endif
130 
131 //----------------------------------------------------------------------
132 // END Debugging support
133 //----------------------------------------------------------------------
134 
135 // Fill the precontext and postcontext with the patterns of the rules
136 // that are masking one another.
maskingError(const icu::TransliterationRule & rule1,const icu::TransliterationRule & rule2,UParseError & parseError)137 static void maskingError(const icu::TransliterationRule& rule1,
138                          const icu::TransliterationRule& rule2,
139                          UParseError& parseError) {
140     icu::UnicodeString r;
141     int32_t len;
142 
143     parseError.line = parseError.offset = -1;
144 
145     // for pre-context
146     rule1.toRule(r, FALSE);
147     len = uprv_min(r.length(), U_PARSE_CONTEXT_LEN-1);
148     r.extract(0, len, parseError.preContext);
149     parseError.preContext[len] = 0;
150 
151     //for post-context
152     r.truncate(0);
153     rule2.toRule(r, FALSE);
154     len = uprv_min(r.length(), U_PARSE_CONTEXT_LEN-1);
155     r.extract(0, len, parseError.postContext);
156     parseError.postContext[len] = 0;
157 }
158 
159 U_NAMESPACE_BEGIN
160 
161 /**
162  * Construct a new empty rule set.
163  */
TransliterationRuleSet(UErrorCode & status)164 TransliterationRuleSet::TransliterationRuleSet(UErrorCode& status) : UMemory() {
165     ruleVector = new UVector(&_deleteRule, NULL, status);
166     if (U_FAILURE(status)) {
167         return;
168     }
169     if (ruleVector == NULL) {
170         status = U_MEMORY_ALLOCATION_ERROR;
171     }
172     rules = NULL;
173     maxContextLength = 0;
174 }
175 
176 /**
177  * Copy constructor.
178  */
TransliterationRuleSet(const TransliterationRuleSet & other)179 TransliterationRuleSet::TransliterationRuleSet(const TransliterationRuleSet& other) :
180     UMemory(other),
181     ruleVector(0),
182     rules(0),
183     maxContextLength(other.maxContextLength) {
184 
185     int32_t i, len;
186     uprv_memcpy(index, other.index, sizeof(index));
187     UErrorCode status = U_ZERO_ERROR;
188     ruleVector = new UVector(&_deleteRule, NULL, status);
189     if (other.ruleVector != 0 && ruleVector != 0 && U_SUCCESS(status)) {
190         len = other.ruleVector->size();
191         for (i=0; i<len && U_SUCCESS(status); ++i) {
192             TransliterationRule *tempTranslitRule = new TransliterationRule(*(TransliterationRule*)other.ruleVector->elementAt(i));
193             // Null pointer test
194             if (tempTranslitRule == NULL) {
195                 status = U_MEMORY_ALLOCATION_ERROR;
196                 break;
197             }
198             ruleVector->addElement(tempTranslitRule, status);
199             if (U_FAILURE(status)) {
200                 break;
201             }
202         }
203     }
204     if (other.rules != 0 && U_SUCCESS(status)) {
205         UParseError p;
206         freeze(p, status);
207     }
208 }
209 
210 /**
211  * Destructor.
212  */
~TransliterationRuleSet()213 TransliterationRuleSet::~TransliterationRuleSet() {
214     delete ruleVector; // This deletes the contained rules
215     uprv_free(rules);
216 }
217 
setData(const TransliterationRuleData * d)218 void TransliterationRuleSet::setData(const TransliterationRuleData* d) {
219     /**
220      * We assume that the ruleset has already been frozen.
221      */
222     int32_t len = index[256]; // see freeze()
223     for (int32_t i=0; i<len; ++i) {
224         rules[i]->setData(d);
225     }
226 }
227 
228 /**
229  * Return the maximum context length.
230  * @return the length of the longest preceding context.
231  */
getMaximumContextLength(void) const232 int32_t TransliterationRuleSet::getMaximumContextLength(void) const {
233     return maxContextLength;
234 }
235 
236 /**
237  * Add a rule to this set.  Rules are added in order, and order is
238  * significant.  The last call to this method must be followed by
239  * a call to <code>freeze()</code> before the rule set is used.
240  *
241  * <p>If freeze() has already been called, calling addRule()
242  * unfreezes the rules, and freeze() must be called again.
243  *
244  * @param adoptedRule the rule to add
245  */
addRule(TransliterationRule * adoptedRule,UErrorCode & status)246 void TransliterationRuleSet::addRule(TransliterationRule* adoptedRule,
247                                      UErrorCode& status) {
248     if (U_FAILURE(status)) {
249         delete adoptedRule;
250         return;
251     }
252     ruleVector->addElement(adoptedRule, status);
253 
254     int32_t len;
255     if ((len = adoptedRule->getContextLength()) > maxContextLength) {
256         maxContextLength = len;
257     }
258 
259     uprv_free(rules);
260     rules = 0;
261 }
262 
263 /**
264  * Check this for masked rules and index it to optimize performance.
265  * The sequence of operations is: (1) add rules to a set using
266  * <code>addRule()</code>; (2) freeze the set using
267  * <code>freeze()</code>; (3) use the rule set.  If
268  * <code>addRule()</code> is called after calling this method, it
269  * invalidates this object, and this method must be called again.
270  * That is, <code>freeze()</code> may be called multiple times,
271  * although for optimal performance it shouldn't be.
272  */
freeze(UParseError & parseError,UErrorCode & status)273 void TransliterationRuleSet::freeze(UParseError& parseError,UErrorCode& status) {
274     /* Construct the rule array and index table.  We reorder the
275      * rules by sorting them into 256 bins.  Each bin contains all
276      * rules matching the index value for that bin.  A rule
277      * matches an index value if string whose first key character
278      * has a low byte equal to the index value can match the rule.
279      *
280      * Each bin contains zero or more rules, in the same order
281      * they were found originally.  However, the total rules in
282      * the bins may exceed the number in the original vector,
283      * since rules that have a variable as their first key
284      * character will generally fall into more than one bin.
285      *
286      * That is, each bin contains all rules that either have that
287      * first index value as their first key character, or have
288      * a set containing the index value as their first character.
289      */
290     int32_t n = ruleVector->size();
291     int32_t j;
292     int16_t x;
293     UVector v(2*n, status); // heuristic; adjust as needed
294 
295     if (U_FAILURE(status)) {
296         return;
297     }
298 
299     /* Precompute the index values.  This saves a LOT of time.
300      * Be careful not to call malloc(0).
301      */
302     int16_t* indexValue = (int16_t*) uprv_malloc( sizeof(int16_t) * (n > 0 ? n : 1) );
303     /* test for NULL */
304     if (indexValue == 0) {
305         status = U_MEMORY_ALLOCATION_ERROR;
306         return;
307     }
308     for (j=0; j<n; ++j) {
309         TransliterationRule* r = (TransliterationRule*) ruleVector->elementAt(j);
310         indexValue[j] = r->getIndexValue();
311     }
312     for (x=0; x<256; ++x) {
313         index[x] = v.size();
314         for (j=0; j<n; ++j) {
315             if (indexValue[j] >= 0) {
316                 if (indexValue[j] == x) {
317                     v.addElement(ruleVector->elementAt(j), status);
318                 }
319             } else {
320                 // If the indexValue is < 0, then the first key character is
321                 // a set, and we must use the more time-consuming
322                 // matchesIndexValue check.  In practice this happens
323                 // rarely, so we seldom tread this code path.
324                 TransliterationRule* r = (TransliterationRule*) ruleVector->elementAt(j);
325                 if (r->matchesIndexValue((uint8_t)x)) {
326                     v.addElement(r, status);
327                 }
328             }
329         }
330     }
331     uprv_free(indexValue);
332     index[256] = v.size();
333 
334     /* Freeze things into an array.
335      */
336     uprv_free(rules); // Contains alias pointers
337 
338     /* You can't do malloc(0)! */
339     if (v.size() == 0) {
340         rules = NULL;
341         return;
342     }
343     rules = (TransliterationRule **)uprv_malloc(v.size() * sizeof(TransliterationRule *));
344     /* test for NULL */
345     if (rules == 0) {
346         status = U_MEMORY_ALLOCATION_ERROR;
347         return;
348     }
349     for (j=0; j<v.size(); ++j) {
350         rules[j] = (TransliterationRule*) v.elementAt(j);
351     }
352 
353     // TODO Add error reporting that indicates the rules that
354     //      are being masked.
355     //UnicodeString errors;
356 
357     /* Check for masking.  This is MUCH faster than our old check,
358      * which was each rule against each following rule, since we
359      * only have to check for masking within each bin now.  It's
360      * 256*O(n2^2) instead of O(n1^2), where n1 is the total rule
361      * count, and n2 is the per-bin rule count.  But n2<<n1, so
362      * it's a big win.
363      */
364     for (x=0; x<256; ++x) {
365         for (j=index[x]; j<index[x+1]-1; ++j) {
366             TransliterationRule* r1 = rules[j];
367             for (int32_t k=j+1; k<index[x+1]; ++k) {
368                 TransliterationRule* r2 = rules[k];
369                 if (r1->masks(*r2)) {
370 //|                 if (errors == null) {
371 //|                     errors = new StringBuffer();
372 //|                 } else {
373 //|                     errors.append("\n");
374 //|                 }
375 //|                 errors.append("Rule " + r1 + " masks " + r2);
376                     status = U_RULE_MASK_ERROR;
377                     maskingError(*r1, *r2, parseError);
378                     return;
379                 }
380             }
381         }
382     }
383 
384     //if (errors != null) {
385     //    throw new IllegalArgumentException(errors.toString());
386     //}
387 }
388 
389 /**
390  * Transliterate the given text with the given UTransPosition
391  * indices.  Return TRUE if the transliteration should continue
392  * or FALSE if it should halt (because of a U_PARTIAL_MATCH match).
393  * Note that FALSE is only ever returned if isIncremental is TRUE.
394  * @param text the text to be transliterated
395  * @param pos the position indices, which will be updated
396  * @param incremental if TRUE, assume new text may be inserted
397  * at index.limit, and return FALSE if thre is a partial match.
398  * @return TRUE unless a U_PARTIAL_MATCH has been obtained,
399  * indicating that transliteration should stop until more text
400  * arrives.
401  */
transliterate(Replaceable & text,UTransPosition & pos,UBool incremental)402 UBool TransliterationRuleSet::transliterate(Replaceable& text,
403                                             UTransPosition& pos,
404                                             UBool incremental) {
405     int16_t indexByte = (int16_t) (text.char32At(pos.start) & 0xFF);
406     for (int32_t i=index[indexByte]; i<index[indexByte+1]; ++i) {
407         UMatchDegree m = rules[i]->matchAndReplace(text, pos, incremental);
408         switch (m) {
409         case U_MATCH:
410             _debugOut("match", rules[i], text, pos);
411             return TRUE;
412         case U_PARTIAL_MATCH:
413             _debugOut("partial match", rules[i], text, pos);
414             return FALSE;
415         default: /* Ram: added default to make GCC happy */
416             break;
417         }
418     }
419     // No match or partial match from any rule
420     pos.start += U16_LENGTH(text.char32At(pos.start));
421     _debugOut("no match", NULL, text, pos);
422     return TRUE;
423 }
424 
425 /**
426  * Create rule strings that represents this rule set.
427  */
toRules(UnicodeString & ruleSource,UBool escapeUnprintable) const428 UnicodeString& TransliterationRuleSet::toRules(UnicodeString& ruleSource,
429                                                UBool escapeUnprintable) const {
430     int32_t i;
431     int32_t count = ruleVector->size();
432     ruleSource.truncate(0);
433     for (i=0; i<count; ++i) {
434         if (i != 0) {
435             ruleSource.append((UChar) 0x000A /*\n*/);
436         }
437         TransliterationRule *r =
438             (TransliterationRule*) ruleVector->elementAt(i);
439         r->toRule(ruleSource, escapeUnprintable);
440     }
441     return ruleSource;
442 }
443 
444 /**
445  * Return the set of all characters that may be modified
446  * (getTarget=false) or emitted (getTarget=true) by this set.
447  */
getSourceTargetSet(UnicodeSet & result,UBool getTarget) const448 UnicodeSet& TransliterationRuleSet::getSourceTargetSet(UnicodeSet& result,
449                                UBool getTarget) const
450 {
451     result.clear();
452     int32_t count = ruleVector->size();
453     for (int32_t i=0; i<count; ++i) {
454         TransliterationRule* r =
455             (TransliterationRule*) ruleVector->elementAt(i);
456         if (getTarget) {
457             r->addTargetSetTo(result);
458         } else {
459             r->addSourceSetTo(result);
460         }
461     }
462     return result;
463 }
464 
465 U_NAMESPACE_END
466 
467 #endif /* #if !UCONFIG_NO_TRANSLITERATION */
468