Check in the pristine copy of ICU 4.6...

icu46/source/i18n/anytrans.cpp

+/*
+*****************************************************************
+* Copyright (c) 2002-2008, International Business Machines Corporation
+* and others.  All Rights Reserved.
+*****************************************************************
+* Date        Name        Description
+* 06/06/2002  aliu        Creation.
+*****************************************************************
+*/
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_TRANSLITERATION
+
+#include "unicode/uobject.h"
+#include "unicode/uscript.h"
+#include "nultrans.h"
+#include "anytrans.h"
+#include "uvector.h"
+#include "tridpars.h"
+#include "hash.h"
+#include "putilimp.h"
+#include "uinvchar.h"
+
+//------------------------------------------------------------
+// Constants
+
+static const UChar TARGET_SEP = 45; // '-'
+static const UChar VARIANT_SEP = 47; // '/'
+static const UChar ANY[] = {65,110,121,0}; // "Any"
+static const UChar NULL_ID[] = {78,117,108,108,0}; // "Null"
+static const UChar LATIN_PIVOT[] = {45,76,97,116,105,110,59,76,97,116,105,110,45,0}; // "-Latin;Latin-"
+
+//------------------------------------------------------------
+
+U_CDECL_BEGIN
+/**
+ * Deleter function for Transliterator*.
+ */
+static void U_CALLCONV
+_deleteTransliterator(void *obj) {
+    delete (U_NAMESPACE_QUALIFIER Transliterator*) obj;    
+}
+U_CDECL_END
+
+//------------------------------------------------------------
+
+U_NAMESPACE_BEGIN
+
+//------------------------------------------------------------
+// ScriptRunIterator
+
+/**
+ * Returns a series of ranges corresponding to scripts. They will be
+ * of the form:
+ *
+ * ccccSScSSccccTTcTcccc   - c = common, S = first script, T = second
+ * |            |          - first run (start, limit)
+ *          |           |  - second run (start, limit)
+ *
+ * That is, the runs will overlap. The reason for this is so that a
+ * transliterator can consider common characters both before and after
+ * the scripts.
+ */
+class ScriptRunIterator : public UMemory {
+private:
+    const Replaceable& text;
+    int32_t textStart;
+    int32_t textLimit;
+
+public:
+    /**
+     * The code of the current run, valid after next() returns.  May
+     * be USCRIPT_INVALID_CODE if and only if the entire text is
+     * COMMON/INHERITED.
+     */
+    UScriptCode scriptCode;
+
+    /**
+     * The start of the run, inclusive, valid after next() returns.
+     */
+    int32_t start;
+
+    /**
+     * The end of the run, exclusive, valid after next() returns.
+     */
+    int32_t limit;
+    
+    /**
+     * Constructs a run iterator over the given text from start
+     * (inclusive) to limit (exclusive).
+     */
+    ScriptRunIterator(const Replaceable& text, int32_t start, int32_t limit);
+
+    /**
+     * Returns TRUE if there are any more runs.  TRUE is always
+     * returned at least once.  Upon return, the caller should
+     * examine scriptCode, start, and limit.
+     */
+    UBool next();
+
+    /**
+     * Adjusts internal indices for a change in the limit index of the
+     * given delta.  A positive delta means the limit has increased.
+     */
+    void adjustLimit(int32_t delta);
+
+private:
+    ScriptRunIterator(const ScriptRunIterator &other); // forbid copying of this class
+    ScriptRunIterator &operator=(const ScriptRunIterator &other); // forbid copying of this class
+};
+
+ScriptRunIterator::ScriptRunIterator(const Replaceable& theText,
+                                     int32_t myStart, int32_t myLimit) :
+    text(theText)
+{
+    textStart = myStart;
+    textLimit = myLimit;
+    limit = myStart;
+}
+
+UBool ScriptRunIterator::next() {
+    UChar32 ch;
+    UScriptCode s;
+    UErrorCode ec = U_ZERO_ERROR;
+
+    scriptCode = USCRIPT_INVALID_CODE; // don't know script yet
+    start = limit;
+
+    // Are we done?
+    if (start == textLimit) {
+        return FALSE;
+    }
+
+    // Move start back to include adjacent COMMON or INHERITED
+    // characters
+    while (start > textStart) {
+        ch = text.char32At(start - 1); // look back
+        s = uscript_getScript(ch, &ec);
+        if (s == USCRIPT_COMMON || s == USCRIPT_INHERITED) {
+            --start;
+        } else {
+            break;
+        }
+    }
+
+    // Move limit ahead to include COMMON, INHERITED, and characters
+    // of the current script.
+    while (limit < textLimit) {
+        ch = text.char32At(limit); // look ahead
+        s = uscript_getScript(ch, &ec);
+        if (s != USCRIPT_COMMON && s != USCRIPT_INHERITED) {
+            if (scriptCode == USCRIPT_INVALID_CODE) {
+                scriptCode = s;
+            } else if (s != scriptCode) {
+                break;
+            }
+        }
+        ++limit;
+    }
+
+    // Return TRUE even if the entire text is COMMON / INHERITED, in
+    // which case scriptCode will be USCRIPT_INVALID_CODE.
+    return TRUE;
+}
+
+void ScriptRunIterator::adjustLimit(int32_t delta) {
+    limit += delta;
+    textLimit += delta;
+}
+
+//------------------------------------------------------------
+// AnyTransliterator
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(AnyTransliterator)
+
+AnyTransliterator::AnyTransliterator(const UnicodeString& id,
+                                     const UnicodeString& theTarget,
+                                     const UnicodeString& theVariant,
+                                     UScriptCode theTargetScript,
+                                     UErrorCode& ec) :
+    Transliterator(id, NULL),
+    targetScript(theTargetScript) 
+{
+    cache = uhash_open(uhash_hashLong, uhash_compareLong, NULL, &ec);
+    if (U_FAILURE(ec)) {
+        return;
+    }
+    uhash_setValueDeleter(cache, _deleteTransliterator);
+
+    target = theTarget;
+    if (theVariant.length() > 0) {
+        target.append(VARIANT_SEP).append(theVariant);
+    }
+}
+
+AnyTransliterator::~AnyTransliterator() {
+    uhash_close(cache);
+}
+
+/**
+ * Copy constructor.
+ */
+AnyTransliterator::AnyTransliterator(const AnyTransliterator& o) :
+    Transliterator(o),
+    target(o.target),
+    targetScript(o.targetScript)
+{
+    // Don't copy the cache contents
+    UErrorCode ec = U_ZERO_ERROR;
+    cache = uhash_open(uhash_hashLong, uhash_compareLong, NULL, &ec);
+    if (U_FAILURE(ec)) {
+        return;
+    }
+    uhash_setValueDeleter(cache, _deleteTransliterator);
+}
+
+/**
+ * Transliterator API.
+ */
+Transliterator* AnyTransliterator::clone() const {
+    return new AnyTransliterator(*this);
+}
+
+/**
+ * Implements {@link Transliterator#handleTransliterate}.
+ */
+void AnyTransliterator::handleTransliterate(Replaceable& text, UTransPosition& pos,
+                                            UBool isIncremental) const {
+    int32_t allStart = pos.start;
+    int32_t allLimit = pos.limit;
+
+    ScriptRunIterator it(text, pos.contextStart, pos.contextLimit);
+
+    while (it.next()) {
+        // Ignore runs in the ante context
+        if (it.limit <= allStart) continue;
+
+        // Try to instantiate transliterator from it.scriptCode to
+        // our target or target/variant
+        Transliterator* t = getTransliterator(it.scriptCode);
+       
+        if (t == NULL) {
+            // We have no transliterator.  Do nothing, but keep
+            // pos.start up to date.
+            pos.start = it.limit;
+            continue;
+        }
+
+        // If the run end is before the transliteration limit, do
+        // a non-incremental transliteration.  Otherwise do an
+        // incremental one.
+        UBool incremental = isIncremental && (it.limit >= allLimit);
+        
+        pos.start = uprv_max(allStart, it.start);
+        pos.limit = uprv_min(allLimit, it.limit);
+        int32_t limit = pos.limit;
+        t->filteredTransliterate(text, pos, incremental);
+        int32_t delta = pos.limit - limit;
+        allLimit += delta;
+        it.adjustLimit(delta);
+
+        // We're done if we enter the post context
+        if (it.limit >= allLimit) break;
+    }
+
+    // Restore limit.  pos.start is fine where the last transliterator
+    // left it, or at the end of the last run.
+    pos.limit = allLimit;
+}
+
+Transliterator* AnyTransliterator::getTransliterator(UScriptCode source) const {
+
+    if (source == targetScript || source == USCRIPT_INVALID_CODE) {
+        return NULL;
+    }
+
+    Transliterator* t = (Transliterator*) uhash_iget(cache, (int32_t) source);
+    if (t == NULL) {
+        UErrorCode ec = U_ZERO_ERROR;
+        UnicodeString sourceName(uscript_getName(source), -1, US_INV);
+        UnicodeString id(sourceName);
+        id.append(TARGET_SEP).append(target);
+        
+        t = Transliterator::createInstance(id, UTRANS_FORWARD, ec);
+        if (U_FAILURE(ec) || t == NULL) {
+            delete t;
+            
+            // Try to pivot around Latin, our most common script
+            id = sourceName;
+            id.append(LATIN_PIVOT).append(target);
+            t = Transliterator::createInstance(id, UTRANS_FORWARD, ec);
+            if (U_FAILURE(ec) || t == NULL) {
+                delete t;
+                t = NULL;
+            }
+        }
+
+        if (t != NULL) {
+            uhash_iput(cache, (int32_t) source, t, &ec);
+        }
+    }
+
+    return t;
+}
+
+/**
+ * Return the script code for a given name, or -1 if not found.
+ */
+static UScriptCode scriptNameToCode(const UnicodeString& name) {
+    char buf[128];
+    UScriptCode code;
+    UErrorCode ec = U_ZERO_ERROR;
+    int32_t nameLen = name.length();
+    UBool isInvariant = uprv_isInvariantUString(name.getBuffer(), nameLen);
+    
+    if (isInvariant) {
+        name.extract(0, nameLen, buf, (int32_t)sizeof(buf), US_INV);
+        buf[127] = 0;   // Make sure that we NULL terminate the string.
+    }
+    if (!isInvariant || uscript_getCode(buf, &code, 1, &ec) != 1 || U_FAILURE(ec))
+    {
+        code = USCRIPT_INVALID_CODE;
+    }
+    return code;
+}
+
+/**
+ * Registers standard transliterators with the system.  Called by
+ * Transliterator during initialization.  Scan all current targets and
+ * register those that are scripts T as Any-T/V.
+ */
+void AnyTransliterator::registerIDs() {
+
+    UErrorCode ec = U_ZERO_ERROR;
+    Hashtable seen(TRUE, ec);
+
+    int32_t sourceCount = Transliterator::_countAvailableSources();
+    for (int32_t s=0; s<sourceCount; ++s) {
+        UnicodeString source;
+        Transliterator::_getAvailableSource(s, source);
+
+        // Ignore the "Any" source
+        if (source.caseCompare(ANY, 0 /*U_FOLD_CASE_DEFAULT*/) == 0) continue;
+
+        int32_t targetCount = Transliterator::_countAvailableTargets(source);
+        for (int32_t t=0; t<targetCount; ++t) {
+            UnicodeString target;
+            Transliterator::_getAvailableTarget(t, source, target);
+
+            // Only process each target once
+            if (seen.geti(target) != 0) continue;
+            ec = U_ZERO_ERROR;
+            seen.puti(target, 1, ec);
+            
+            // Get the script code for the target.  If not a script, ignore.
+            UScriptCode targetScript = scriptNameToCode(target);
+            if (targetScript == USCRIPT_INVALID_CODE) continue;
+
+            int32_t variantCount = Transliterator::_countAvailableVariants(source, target);
+            // assert(variantCount >= 1);
+            for (int32_t v=0; v<variantCount; ++v) {
+                UnicodeString variant;
+                Transliterator::_getAvailableVariant(v, source, target, variant);
+                
+                UnicodeString id;
+                TransliteratorIDParser::STVtoID(ANY, target, variant, id);
+                ec = U_ZERO_ERROR;
+                AnyTransliterator* t = new AnyTransliterator(id, target, variant,
+                                                             targetScript, ec);
+                if (U_FAILURE(ec)) {
+                    delete t;
+                } else {
+                    Transliterator::_registerInstance(t);
+                    Transliterator::_registerSpecialInverse(target, NULL_ID, FALSE);
+                }
+            }
+        }
+    }
+}
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_TRANSLITERATION */
+
+//eof