michael@0: /*
michael@0: *****************************************************************
michael@0: * Copyright (c) 2002-2011, International Business Machines Corporation
michael@0: * and others.  All Rights Reserved.
michael@0: *****************************************************************
michael@0: * Date        Name        Description
michael@0: * 06/06/2002  aliu        Creation.
michael@0: *****************************************************************
michael@0: */
michael@0: 
michael@0: #include "unicode/utypes.h"
michael@0: 
michael@0: #if !UCONFIG_NO_TRANSLITERATION
michael@0: 
michael@0: #include "unicode/uobject.h"
michael@0: #include "unicode/uscript.h"
michael@0: #include "nultrans.h"
michael@0: #include "anytrans.h"
michael@0: #include "uvector.h"
michael@0: #include "tridpars.h"
michael@0: #include "hash.h"
michael@0: #include "putilimp.h"
michael@0: #include "uinvchar.h"
michael@0: 
michael@0: //------------------------------------------------------------
michael@0: // Constants
michael@0: 
michael@0: static const UChar TARGET_SEP = 45; // '-'
michael@0: static const UChar VARIANT_SEP = 47; // '/'
michael@0: static const UChar ANY[] = {65,110,121,0}; // "Any"
michael@0: static const UChar NULL_ID[] = {78,117,108,108,0}; // "Null"
michael@0: static const UChar LATIN_PIVOT[] = {45,76,97,116,105,110,59,76,97,116,105,110,45,0}; // "-Latin;Latin-"
michael@0: 
michael@0: //------------------------------------------------------------
michael@0: 
michael@0: U_CDECL_BEGIN
michael@0: /**
michael@0:  * Deleter function for Transliterator*.
michael@0:  */
michael@0: static void U_CALLCONV
michael@0: _deleteTransliterator(void *obj) {
michael@0:     delete (icu::Transliterator*) obj;    
michael@0: }
michael@0: U_CDECL_END
michael@0: 
michael@0: //------------------------------------------------------------
michael@0: 
michael@0: U_NAMESPACE_BEGIN
michael@0: 
michael@0: //------------------------------------------------------------
michael@0: // ScriptRunIterator
michael@0: 
michael@0: /**
michael@0:  * Returns a series of ranges corresponding to scripts. They will be
michael@0:  * of the form:
michael@0:  *
michael@0:  * ccccSScSSccccTTcTcccc   - c = common, S = first script, T = second
michael@0:  * |            |          - first run (start, limit)
michael@0:  *          |           |  - second run (start, limit)
michael@0:  *
michael@0:  * That is, the runs will overlap. The reason for this is so that a
michael@0:  * transliterator can consider common characters both before and after
michael@0:  * the scripts.
michael@0:  */
michael@0: class ScriptRunIterator : public UMemory {
michael@0: private:
michael@0:     const Replaceable& text;
michael@0:     int32_t textStart;
michael@0:     int32_t textLimit;
michael@0: 
michael@0: public:
michael@0:     /**
michael@0:      * The code of the current run, valid after next() returns.  May
michael@0:      * be USCRIPT_INVALID_CODE if and only if the entire text is
michael@0:      * COMMON/INHERITED.
michael@0:      */
michael@0:     UScriptCode scriptCode;
michael@0: 
michael@0:     /**
michael@0:      * The start of the run, inclusive, valid after next() returns.
michael@0:      */
michael@0:     int32_t start;
michael@0: 
michael@0:     /**
michael@0:      * The end of the run, exclusive, valid after next() returns.
michael@0:      */
michael@0:     int32_t limit;
michael@0:     
michael@0:     /**
michael@0:      * Constructs a run iterator over the given text from start
michael@0:      * (inclusive) to limit (exclusive).
michael@0:      */
michael@0:     ScriptRunIterator(const Replaceable& text, int32_t start, int32_t limit);
michael@0: 
michael@0:     /**
michael@0:      * Returns TRUE if there are any more runs.  TRUE is always
michael@0:      * returned at least once.  Upon return, the caller should
michael@0:      * examine scriptCode, start, and limit.
michael@0:      */
michael@0:     UBool next();
michael@0: 
michael@0:     /**
michael@0:      * Adjusts internal indices for a change in the limit index of the
michael@0:      * given delta.  A positive delta means the limit has increased.
michael@0:      */
michael@0:     void adjustLimit(int32_t delta);
michael@0: 
michael@0: private:
michael@0:     ScriptRunIterator(const ScriptRunIterator &other); // forbid copying of this class
michael@0:     ScriptRunIterator &operator=(const ScriptRunIterator &other); // forbid copying of this class
michael@0: };
michael@0: 
michael@0: ScriptRunIterator::ScriptRunIterator(const Replaceable& theText,
michael@0:                                      int32_t myStart, int32_t myLimit) :
michael@0:     text(theText)
michael@0: {
michael@0:     textStart = myStart;
michael@0:     textLimit = myLimit;
michael@0:     limit = myStart;
michael@0: }
michael@0: 
michael@0: UBool ScriptRunIterator::next() {
michael@0:     UChar32 ch;
michael@0:     UScriptCode s;
michael@0:     UErrorCode ec = U_ZERO_ERROR;
michael@0: 
michael@0:     scriptCode = USCRIPT_INVALID_CODE; // don't know script yet
michael@0:     start = limit;
michael@0: 
michael@0:     // Are we done?
michael@0:     if (start == textLimit) {
michael@0:         return FALSE;
michael@0:     }
michael@0: 
michael@0:     // Move start back to include adjacent COMMON or INHERITED
michael@0:     // characters
michael@0:     while (start > textStart) {
michael@0:         ch = text.char32At(start - 1); // look back
michael@0:         s = uscript_getScript(ch, &ec);
michael@0:         if (s == USCRIPT_COMMON || s == USCRIPT_INHERITED) {
michael@0:             --start;
michael@0:         } else {
michael@0:             break;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     // Move limit ahead to include COMMON, INHERITED, and characters
michael@0:     // of the current script.
michael@0:     while (limit < textLimit) {
michael@0:         ch = text.char32At(limit); // look ahead
michael@0:         s = uscript_getScript(ch, &ec);
michael@0:         if (s != USCRIPT_COMMON && s != USCRIPT_INHERITED) {
michael@0:             if (scriptCode == USCRIPT_INVALID_CODE) {
michael@0:                 scriptCode = s;
michael@0:             } else if (s != scriptCode) {
michael@0:                 break;
michael@0:             }
michael@0:         }
michael@0:         ++limit;
michael@0:     }
michael@0: 
michael@0:     // Return TRUE even if the entire text is COMMON / INHERITED, in
michael@0:     // which case scriptCode will be USCRIPT_INVALID_CODE.
michael@0:     return TRUE;
michael@0: }
michael@0: 
michael@0: void ScriptRunIterator::adjustLimit(int32_t delta) {
michael@0:     limit += delta;
michael@0:     textLimit += delta;
michael@0: }
michael@0: 
michael@0: //------------------------------------------------------------
michael@0: // AnyTransliterator
michael@0: 
michael@0: UOBJECT_DEFINE_RTTI_IMPLEMENTATION(AnyTransliterator)
michael@0: 
michael@0: AnyTransliterator::AnyTransliterator(const UnicodeString& id,
michael@0:                                      const UnicodeString& theTarget,
michael@0:                                      const UnicodeString& theVariant,
michael@0:                                      UScriptCode theTargetScript,
michael@0:                                      UErrorCode& ec) :
michael@0:     Transliterator(id, NULL),
michael@0:     targetScript(theTargetScript) 
michael@0: {
michael@0:     cache = uhash_open(uhash_hashLong, uhash_compareLong, NULL, &ec);
michael@0:     if (U_FAILURE(ec)) {
michael@0:         return;
michael@0:     }
michael@0:     uhash_setValueDeleter(cache, _deleteTransliterator);
michael@0: 
michael@0:     target = theTarget;
michael@0:     if (theVariant.length() > 0) {
michael@0:         target.append(VARIANT_SEP).append(theVariant);
michael@0:     }
michael@0: }
michael@0: 
michael@0: AnyTransliterator::~AnyTransliterator() {
michael@0:     uhash_close(cache);
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Copy constructor.
michael@0:  */
michael@0: AnyTransliterator::AnyTransliterator(const AnyTransliterator& o) :
michael@0:     Transliterator(o),
michael@0:     target(o.target),
michael@0:     targetScript(o.targetScript)
michael@0: {
michael@0:     // Don't copy the cache contents
michael@0:     UErrorCode ec = U_ZERO_ERROR;
michael@0:     cache = uhash_open(uhash_hashLong, uhash_compareLong, NULL, &ec);
michael@0:     if (U_FAILURE(ec)) {
michael@0:         return;
michael@0:     }
michael@0:     uhash_setValueDeleter(cache, _deleteTransliterator);
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Transliterator API.
michael@0:  */
michael@0: Transliterator* AnyTransliterator::clone() const {
michael@0:     return new AnyTransliterator(*this);
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Implements {@link Transliterator#handleTransliterate}.
michael@0:  */
michael@0: void AnyTransliterator::handleTransliterate(Replaceable& text, UTransPosition& pos,
michael@0:                                             UBool isIncremental) const {
michael@0:     int32_t allStart = pos.start;
michael@0:     int32_t allLimit = pos.limit;
michael@0: 
michael@0:     ScriptRunIterator it(text, pos.contextStart, pos.contextLimit);
michael@0: 
michael@0:     while (it.next()) {
michael@0:         // Ignore runs in the ante context
michael@0:         if (it.limit <= allStart) continue;
michael@0: 
michael@0:         // Try to instantiate transliterator from it.scriptCode to
michael@0:         // our target or target/variant
michael@0:         Transliterator* t = getTransliterator(it.scriptCode);
michael@0:        
michael@0:         if (t == NULL) {
michael@0:             // We have no transliterator.  Do nothing, but keep
michael@0:             // pos.start up to date.
michael@0:             pos.start = it.limit;
michael@0:             continue;
michael@0:         }
michael@0: 
michael@0:         // If the run end is before the transliteration limit, do
michael@0:         // a non-incremental transliteration.  Otherwise do an
michael@0:         // incremental one.
michael@0:         UBool incremental = isIncremental && (it.limit >= allLimit);
michael@0:         
michael@0:         pos.start = uprv_max(allStart, it.start);
michael@0:         pos.limit = uprv_min(allLimit, it.limit);
michael@0:         int32_t limit = pos.limit;
michael@0:         t->filteredTransliterate(text, pos, incremental);
michael@0:         int32_t delta = pos.limit - limit;
michael@0:         allLimit += delta;
michael@0:         it.adjustLimit(delta);
michael@0: 
michael@0:         // We're done if we enter the post context
michael@0:         if (it.limit >= allLimit) break;
michael@0:     }
michael@0: 
michael@0:     // Restore limit.  pos.start is fine where the last transliterator
michael@0:     // left it, or at the end of the last run.
michael@0:     pos.limit = allLimit;
michael@0: }
michael@0: 
michael@0: Transliterator* AnyTransliterator::getTransliterator(UScriptCode source) const {
michael@0: 
michael@0:     if (source == targetScript || source == USCRIPT_INVALID_CODE) {
michael@0:         return NULL;
michael@0:     }
michael@0: 
michael@0:     Transliterator* t = (Transliterator*) uhash_iget(cache, (int32_t) source);
michael@0:     if (t == NULL) {
michael@0:         UErrorCode ec = U_ZERO_ERROR;
michael@0:         UnicodeString sourceName(uscript_getName(source), -1, US_INV);
michael@0:         UnicodeString id(sourceName);
michael@0:         id.append(TARGET_SEP).append(target);
michael@0:         
michael@0:         t = Transliterator::createInstance(id, UTRANS_FORWARD, ec);
michael@0:         if (U_FAILURE(ec) || t == NULL) {
michael@0:             delete t;
michael@0:             
michael@0:             // Try to pivot around Latin, our most common script
michael@0:             id = sourceName;
michael@0:             id.append(LATIN_PIVOT, -1).append(target);
michael@0:             t = Transliterator::createInstance(id, UTRANS_FORWARD, ec);
michael@0:             if (U_FAILURE(ec) || t == NULL) {
michael@0:                 delete t;
michael@0:                 t = NULL;
michael@0:             }
michael@0:         }
michael@0: 
michael@0:         if (t != NULL) {
michael@0:             uhash_iput(cache, (int32_t) source, t, &ec);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     return t;
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Return the script code for a given name, or -1 if not found.
michael@0:  */
michael@0: static UScriptCode scriptNameToCode(const UnicodeString& name) {
michael@0:     char buf[128];
michael@0:     UScriptCode code;
michael@0:     UErrorCode ec = U_ZERO_ERROR;
michael@0:     int32_t nameLen = name.length();
michael@0:     UBool isInvariant = uprv_isInvariantUString(name.getBuffer(), nameLen);
michael@0:     
michael@0:     if (isInvariant) {
michael@0:         name.extract(0, nameLen, buf, (int32_t)sizeof(buf), US_INV);
michael@0:         buf[127] = 0;   // Make sure that we NULL terminate the string.
michael@0:     }
michael@0:     if (!isInvariant || uscript_getCode(buf, &code, 1, &ec) != 1 || U_FAILURE(ec))
michael@0:     {
michael@0:         code = USCRIPT_INVALID_CODE;
michael@0:     }
michael@0:     return code;
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Registers standard transliterators with the system.  Called by
michael@0:  * Transliterator during initialization.  Scan all current targets and
michael@0:  * register those that are scripts T as Any-T/V.
michael@0:  */
michael@0: void AnyTransliterator::registerIDs() {
michael@0: 
michael@0:     UErrorCode ec = U_ZERO_ERROR;
michael@0:     Hashtable seen(TRUE, ec);
michael@0: 
michael@0:     int32_t sourceCount = Transliterator::_countAvailableSources();
michael@0:     for (int32_t s=0; s<sourceCount; ++s) {
michael@0:         UnicodeString source;
michael@0:         Transliterator::_getAvailableSource(s, source);
michael@0: 
michael@0:         // Ignore the "Any" source
michael@0:         if (source.caseCompare(ANY, 3, 0 /*U_FOLD_CASE_DEFAULT*/) == 0) continue;
michael@0: 
michael@0:         int32_t targetCount = Transliterator::_countAvailableTargets(source);
michael@0:         for (int32_t t=0; t<targetCount; ++t) {
michael@0:             UnicodeString target;
michael@0:             Transliterator::_getAvailableTarget(t, source, target);
michael@0: 
michael@0:             // Only process each target once
michael@0:             if (seen.geti(target) != 0) continue;
michael@0:             ec = U_ZERO_ERROR;
michael@0:             seen.puti(target, 1, ec);
michael@0:             
michael@0:             // Get the script code for the target.  If not a script, ignore.
michael@0:             UScriptCode targetScript = scriptNameToCode(target);
michael@0:             if (targetScript == USCRIPT_INVALID_CODE) continue;
michael@0: 
michael@0:             int32_t variantCount = Transliterator::_countAvailableVariants(source, target);
michael@0:             // assert(variantCount >= 1);
michael@0:             for (int32_t v=0; v<variantCount; ++v) {
michael@0:                 UnicodeString variant;
michael@0:                 Transliterator::_getAvailableVariant(v, source, target, variant);
michael@0:                 
michael@0:                 UnicodeString id;
michael@0:                 TransliteratorIDParser::STVtoID(UnicodeString(TRUE, ANY, 3), target, variant, id);
michael@0:                 ec = U_ZERO_ERROR;
michael@0:                 AnyTransliterator* t = new AnyTransliterator(id, target, variant,
michael@0:                                                              targetScript, ec);
michael@0:                 if (U_FAILURE(ec)) {
michael@0:                     delete t;
michael@0:                 } else {
michael@0:                     Transliterator::_registerInstance(t);
michael@0:                     Transliterator::_registerSpecialInverse(target, UnicodeString(TRUE, NULL_ID, 4), FALSE);
michael@0:                 }
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: }
michael@0: 
michael@0: U_NAMESPACE_END
michael@0: 
michael@0: #endif /* #if !UCONFIG_NO_TRANSLITERATION */
michael@0: 
michael@0: //eof