scuffed-code/icu4c/source/i18n/translit.cpp
1999-12-01 21:27:44 +00:00

883 lines
31 KiB
C++

/*
**********************************************************************
* Copyright (C) 1999, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
* Date Name Description
* 11/17/99 aliu Creation.
**********************************************************************
*/
#include "translit.h"
#include "cmemory.h"
#include "cstring.h"
#include "hextouni.h"
#include "locid.h"
#include "msgfmt.h"
#include "mutex.h"
#include "rbt_data.h"
#include "rbt_pars.h"
#include "rep.h"
#include "resbund.h"
#include "uhash.h"
#include "unifilt.h"
#include "unitohex.h"
/**
* Dictionary of known transliterators. Keys are <code>String</code>
* names, values are one of the following:
*
* <ul><li><code>Transliterator</code> objects
*
* <li><code>RULE_BASED_PLACEHOLDER</code>, in which case the ID
* will have its first '-' removed and be appended to
* RB_RULE_BASED_PREFIX to form a resource bundle name from which
* the RB_RULE key is looked up to obtain the rule.
*
* <li><code>REVERSE_RULE_BASED_PLACEHOLDER</code>. Like
* <code>RULE_BASED_PLACEHOLDER</code>, except the entity names in
* the ID are reversed, and the argument
* RuleBasedTransliterator::REVERSE is pased to the
* RuleBasedTransliterator constructor.
* </ul>
*/
UHashtable* Transliterator::cache = 0;
/**
* The mutex controlling access to the cache.
*/
UMTX Transliterator::cacheMutex = NULL;
/**
* When set to TRUE, the cache has been initialized. Any code must
* check this boolean before accessing the cache, and if the boolean
* is FALSE, it must call initializeCache(). We do this form of lazy
* evaluation for two reasons: (1) so we don't initialize if we don't
* have to (i.e., if no one is using Transliterator, but has included
* the code as part of a shared library, and (2) to avoid static
* intialization problems.
*/
bool_t Transliterator::cacheInitialized = FALSE;
/**
* Prefix for resource bundle key for the display name for a
* transliterator. The ID is appended to this to form the key.
* The resource bundle value should be a String.
*/
const char* Transliterator::RB_DISPLAY_NAME_PREFIX = "T:";
/**
* Resource bundle key for display name pattern.
* The resource bundle value should be a String forming a
* MessageFormat pattern, e.g.:
* "{0,choice,0#|1#{1} Transliterator|2#{1} to {2} Transliterator}".
*/
const char* Transliterator::RB_DISPLAY_NAME_PATTERN =
"TransliteratorNamePattern";
/**
* Resource bundle key for the list of RuleBasedTransliterator IDs.
* The resource bundle value should be a String[] with each element
* being a valid ID. The ID will be appended to RB_RULE_BASED_PREFIX
* to obtain the class name in which the RB_RULE key will be sought.
*/
const char* Transliterator::RB_RULE_BASED_IDS =
"RuleBasedTransliteratorIDs";
/**
* Resource bundle key for the RuleBasedTransliterator rule.
*/
const char* Transliterator::RB_RULE = "Rule";
/**
* Default constructor.
* @param theID the string identifier for this transliterator
* @param theFilter the filter. Any character for which
* <tt>filter.isIn()</tt> returns <tt>false</tt> will not be
* altered by this transliterator. If <tt>filter</tt> is
* <tt>null</tt> then no filtering is applied.
*/
Transliterator::Transliterator(const UnicodeString& theID,
UnicodeFilter* adoptedFilter) :
ID(theID), filter(adoptedFilter) {}
/**
* Destructor.
*/
Transliterator::~Transliterator() {
delete filter;
}
/**
* Copy constructor.
*/
Transliterator::Transliterator(const Transliterator& other) :
ID(other.ID), filter(0) {
if (other.filter != 0) {
// We own the filter, so we must have our own copy
filter = other.filter->clone();
}
}
/**
* Assignment operator.
*/
Transliterator& Transliterator::operator=(const Transliterator& other) {
ID = other.ID;
filter = (other.filter == 0) ?
0 : other.filter->clone();
return *this;
}
/**
* Transliterates the segment of a string that begins at the character
* at offset <code>start</code> and extends to the character at offset
* <code>limit - 1</code>. A default implementation is provided here;
* subclasses should provide a more efficient implementation if
* possible.
* @param text the string to be transliterated
* @param start the beginning index, inclusive; <code>0 <= start
* <= limit</code>.
* @param limit the ending index, exclusive; <code>start <= limit
* <= text.length()</code>.
* @param result buffer to receive the transliterated text; previous
* contents are discarded
*/
void Transliterator::transliterate(const UnicodeString& text,
int32_t start, int32_t limit,
UnicodeString& result) const {
/* This is a default implementation that should be replaced by
* a more efficient subclass implementation if possible.
*/
text.extractBetween(start, limit, result);
transliterate(result);
}
/**
* Transliterates an entire string. Convenience method.
* @param text the string to be transliterated
* @param result buffer to receive the transliterated text; previous
* contents are discarded
*/
void Transliterator::transliterate(const UnicodeString& text,
UnicodeString& result) const {
transliterate(text, 0, text.length(), result);
}
/**
* Transliterates an entire string in place. Convenience method.
* @param text the string to be transliterated
*/
void Transliterator::transliterate(Replaceable& text) const {
transliterate(text, 0, text.length());
}
/**
* Transliterates the portion of the text buffer that can be
* transliterated unambiguosly after new text has been inserted,
* typically as a result of a keyboard event. The new text in
* <code>insertion</code> will be inserted into <code>text</code>
* at <code>index[LIMIT]</code>, advancing
* <code>index[LIMIT]</code> by <code>insertion.length()</code>.
* Then the transliterator will try to transliterate characters of
* <code>text</code> between <code>index[CURSOR]</code> and
* <code>index[LIMIT]</code>. Characters before
* <code>index[CURSOR]</code> will not be changed.
*
* <p>Upon return, values in <code>index[]</code> will be updated.
* <code>index[START]</code> will be advanced to the first
* character that future calls to this method will read.
* <code>index[CURSOR]</code> and <code>index[LIMIT]</code> will
* be adjusted to delimit the range of text that future calls to
* this method may change.
*
* <p>Typical usage of this method begins with an initial call
* with <code>index[START]</code> and <code>index[LIMIT]</code>
* set to indicate the portion of <code>text</code> to be
* transliterated, and <code>index[CURSOR] == index[START]</code>.
* Thereafter, <code>index[]</code> can be used without
* modification in future calls, provided that all changes to
* <code>text</code> are made via this method.
*
* <p>This method assumes that future calls may be made that will
* insert new text into the buffer. As a result, it only performs
* unambiguous transliterations. After the last call to this
* method, there may be untransliterated text that is waiting for
* more input to resolve an ambiguity. In order to perform these
* pending transliterations, clients should call {@link
* #finishKeyboardTransliteration} after the last call to this
* method has been made.
*
* @param text the buffer holding transliterated and untransliterated text
* @param index an array of three integers.
*
* <ul><li><code>index[START]</code>: the beginning index,
* inclusive; <code>0 <= index[START] <= index[LIMIT]</code>.
*
* <li><code>index[LIMIT]</code>: the ending index, exclusive;
* <code>index[START] <= index[LIMIT] <= text.length()</code>.
* <code>insertion</code> is inserted at
* <code>index[LIMIT]</code>.
*
* <li><code>index[CURSOR]</code>: the next character to be
* considered for transliteration; <code>index[START] <=
* index[CURSOR] <= index[LIMIT]</code>. Characters before
* <code>index[CURSOR]</code> will not be changed by future calls
* to this method.</ul>
*
* @param insertion text to be inserted and possibly
* transliterated into the translation buffer at
* <code>index[LIMIT]</code>. If <code>null</code> then no text
* is inserted.
* @see #START
* @see #LIMIT
* @see #CURSOR
* @see #handleKeyboardTransliterate
* @exception IllegalArgumentException if <code>index[]</code>
* is invalid
*/
void Transliterator::keyboardTransliterate(Replaceable& text,
int32_t index[3],
const UnicodeString& insertion,
UErrorCode &status) const {
_keyboardTransliterate(text, index, &insertion, status);
}
/**
* Transliterates the portion of the text buffer that can be
* transliterated unambiguosly after a new character has been
* inserted, typically as a result of a keyboard event. This is a
* convenience method; see {@link
* #keyboardTransliterate(Replaceable, int[], String)} for details.
* @param text the buffer holding transliterated and
* untransliterated text
* @param index an array of three integers. See {@link
* #keyboardTransliterate(Replaceable, int[], String)}.
* @param insertion text to be inserted and possibly
* transliterated into the translation buffer at
* <code>index[LIMIT]</code>.
* @see #keyboardTransliterate(Replaceable, int[], String)
*/
void Transliterator::keyboardTransliterate(Replaceable& text,
int32_t index[3],
UChar insertion,
UErrorCode& status) const {
UnicodeString str(insertion);
_keyboardTransliterate(text, index, &str, status);
}
/**
* Transliterates the portion of the text buffer that can be
* transliterated unambiguosly. This is a convenience method; see
* {@link #keyboardTransliterate(Replaceable, int[], String)} for
* details.
* @param text the buffer holding transliterated and
* untransliterated text
* @param index an array of three integers. See {@link
* #keyboardTransliterate(Replaceable, int[], String)}.
* @see #keyboardTransliterate(Replaceable, int[], String)
*/
void Transliterator::keyboardTransliterate(Replaceable& text,
int32_t index[3],
UErrorCode& status) const {
_keyboardTransliterate(text, index, 0, status);
}
/**
* Finishes any pending transliterations that were waiting for
* more characters. Clients should call this method as the last
* call after a sequence of one or more calls to
* <code>keyboardTransliterate()</code>.
* @param text the buffer holding transliterated and
* untransliterated text.
* @param index the array of indices previously passed to {@link
* #keyboardTransliterate}
*/
void Transliterator::finishKeyboardTransliteration(Replaceable& text,
int32_t index[3]) const {
transliterate(text, index[START], index[LIMIT]);
}
/**
* This internal method does keyboard transliteration. If the
* 'insertion' is non-null then we append it to 'text' before
* proceeding. This method calls through to the pure virtual
* framework method handleKeyboardTransliterate() to do the actual
* work.
*/
void Transliterator::_keyboardTransliterate(Replaceable& text,
int32_t index[3],
const UnicodeString* insertion,
UErrorCode &status) const {
if (U_FAILURE(status)) {
return;
}
if (index[START] < 0 ||
index[LIMIT] > text.length() ||
index[CURSOR] < index[START] ||
index[CURSOR] > index[LIMIT]) {
status = U_ILLEGAL_ARGUMENT_ERROR;
return;
}
int32_t originalStart = index[START];
if (insertion != 0) {
text.handleReplaceBetween(index[LIMIT], index[LIMIT], *insertion);
index[LIMIT] += insertion->length();
}
handleKeyboardTransliterate(text, index);
index[START] = icu_max(index[CURSOR] - getMaximumContextLength(),
originalStart);
}
/**
* Returns the length of the longest context required by this transliterator.
* This is <em>preceding</em> context. The default implementation supplied
* by <code>Transliterator</code> returns zero; subclasses
* that use preceding context should override this method to return the
* correct value. For example, if a transliterator translates "ddd" (where
* d is any digit) to "555" when preceded by "(ddd)", then the preceding
* context length is 5, the length of "(ddd)".
*
* @return The maximum number of preceding context characters this
* transliterator needs to examine
*/
int32_t Transliterator::getMaximumContextLength() const {
return 0;
}
/**
* Returns a programmatic identifier for this transliterator.
* If this identifier is passed to <code>getInstance()</code>, it
* will return this object, if it has been registered.
* @see #registerInstance
* @see #getAvailableIDs
*/
const UnicodeString& Transliterator::getID() const {
return ID;
}
/**
* Returns a name for this transliterator that is appropriate for
* display to the user in the default locale. See {@link
* #getDisplayName(Locale)} for details.
*/
UnicodeString& Transliterator::getDisplayName(UnicodeString& result) const {
return getDisplayName(Locale::getDefault(), result);
}
/**
* Returns a name for this transliterator that is appropriate for
* display to the user in the given locale. This name is taken
* from the locale resource data in the standard manner of the
* <code>java.text</code> package.
*
* <p>If no localized names exist in the system resource bundles,
* a name is synthesized using a localized
* <code>MessageFormat</code> pattern from the resource data. The
* arguments to this pattern are an integer followed by one or two
* strings. The integer is the number of strings, either 1 or 2.
* The strings are formed by splitting the ID for this
* transliterator at the first '-'. If there is no '-', then the
* entire ID forms the only string.
* @param inLocale the Locale in which the display name should be
* localized.
* @see java.text.MessageFormat
*/
UnicodeString& Transliterator::getDisplayName(const Locale& inLocale,
UnicodeString& result) const {
UErrorCode status = U_ZERO_ERROR;
ResourceBundle bundle(Locale::getDataDirectory(), inLocale, status);
// Suspend checking status until later...
// build the char* key
char key[100];
icu_strcpy(key, RB_DISPLAY_NAME_PREFIX);
int32_t length=icu_strlen(RB_DISPLAY_NAME_PREFIX);
key[ID.extract(0, sizeof(key)-length-1, key+length, "")]=0;
// Try to retrieve a UnicodeString* from the bundle. The result,
// if any, should NOT be deleted.
const UnicodeString* resString = bundle.getString(key, status);
if (U_SUCCESS(status) && resString != 0) {
return result = *resString; // [sic] assign & return
}
// We have failed to get a name from the locale data. This is
// typical, since most transliterators will not have localized
// name data. The next step is to retrieve the MessageFormat
// pattern from the locale data and to use it to synthesize the
// name from the ID.
status = U_ZERO_ERROR;
resString = bundle.getString(RB_DISPLAY_NAME_PATTERN, status);
if (U_SUCCESS(status) && resString != 0) {
MessageFormat msg(*resString, inLocale, status);
// Suspend checking status until later...
// We pass either 2 or 3 Formattable objects to msg.
Formattable args[3];
int32_t i = ID.indexOf((UChar)'-');
int32_t nargs;
if (i < 0) {
args[0].setLong(1); // # of args to follow
args[1].setString(ID);
nargs = 2;
} else {
UnicodeString left, right;
ID.extractBetween(0, i, left);
ID.extractBetween(i+1, ID.length(), right);
args[0].setLong(2); // # of args to follow
args[1].setString(left);
args[2].setString(right);
nargs = 3;
}
FieldPosition pos; // ignored by msg
msg.format(args, nargs, result, pos, status);
if (U_SUCCESS(status)) {
return result;
}
}
// We should not reach this point unless there is something
// wrong with the build or the RB_DISPLAY_NAME_PATTERN has
// been deleted from the root RB_LOCALE_ELEMENTS resource.
result = ID;
return result;
}
/**
* Returns the filter used by this transliterator, or <tt>null</tt>
* if this transliterator uses no filter. Caller musn't delete
* the result!
*/
const UnicodeFilter* Transliterator::getFilter() const {
return filter;
}
/**
* Changes the filter used by this transliterator. If the filter
* is set to <tt>null</tt> then no filtering will occur.
*
* <p>Callers must take care if a transliterator is in use by
* multiple threads. The filter should not be changed by one
* thread while another thread may be transliterating.
*/
void Transliterator::adoptFilter(UnicodeFilter* filterToAdopt) {
delete filter;
filter = filterToAdopt;
}
/**
* Returns this transliterator's inverse. See the class
* documentation for details. This implementation simply inverts
* the two entities in the ID and attempts to retrieve the
* resulting transliterator. That is, if <code>getID()</code>
* returns "A-B", then this method will return the result of
* <code>getInstance("B-A")</code>, or <code>null</code> if that
* call fails.
*
* <p>This method does not take filtering into account. The
* returned transliterator will have no filter.
*
* <p>Subclasses with knowledge of their inverse may wish to
* override this method.
*
* @return a transliterator that is an inverse, not necessarily
* exact, of this transliterator, or <code>null</code> if no such
* transliterator is registered.
* @see #registerInstance
*/
Transliterator* Transliterator::createInverse() const {
int32_t i = ID.indexOf((UChar)'-');
if (i >= 0) {
UnicodeString inverseID, right;
ID.extractBetween(i+1, ID.length(), inverseID);
ID.extractBetween(0, i, right);
inverseID.append((UChar)'-').append(right);
return _createInstance(inverseID);
}
return 0;
}
/**
* Returns a <code>Transliterator</code> object given its ID.
* The ID must be either a system transliterator ID or a ID registered
* using <code>registerInstance()</code>.
*
* @param ID a valid ID, as enumerated by <code>getAvailableIDs()</code>
* @return A <code>Transliterator</code> object with the given ID
* @exception IllegalArgumentException if the given ID is invalid.
* @see #registerInstance
* @see #getAvailableIDs
* @see #getID
*/
Transliterator* Transliterator::createInstance(const UnicodeString& ID) {
Transliterator* t = _createInstance(ID);
return t;
}
/**
* This is the path to the subdirectory within the locale data
* directory that contains the rule-based transliterator resource
* bundle files. This is constructed dynamically the first time
* Transliterator::getDataDirectory() is called.
*/
char* Transliterator::DATA_DIR = 0;
/**
* This is the name of a subdirectory within the locale data directory
* that contains the rule-based transliterator resource bundle files.
*/
const char* Transliterator::RESOURCE_SUB_DIR = "translit";
/**
* Returns the directory in which the transliterator resource bundle
* files are located. This is a subdirectory, named RESOURCE_SUB_DIR,
* under Locale::getDataDirectory(). It ends in a path separator.
*/
const char* Transliterator::getDataDirectory() {
if (DATA_DIR == 0) {
Mutex lock; // Okay to use the global mutex here
if (DATA_DIR == 0) {
/* Construct the transliterator data directory path. This
* is a subdirectory of the locale data directory. For
* now, we get the separator from the data directory
* assuming a path separator of one character. In the
* future we might add API to get the separator.
*
* TODO: Fix this to get the path separator in some better
* way. File an rfe for this.
*/
const char* data = Locale::getDataDirectory();
int32_t len = icu_strlen(data);
char sep[2];
sep[0] = data[len-1];
sep[1] = 0;
DATA_DIR = (char*) icu_malloc(
len + icu_strlen(RESOURCE_SUB_DIR) + 2);
if (DATA_DIR == 0) {
// This is a fatal unrecoverable error -- what should we do?
}
icu_strcpy(DATA_DIR, data);
icu_strcat(DATA_DIR, RESOURCE_SUB_DIR);
icu_strcat(DATA_DIR, sep);
}
}
return DATA_DIR;
}
inline int32_t Transliterator::hash(const UnicodeString& str) {
return str.hashCode() & 0x7FFFFFFF;
}
/**
* Returns a transliterator object given its ID. Unlike getInstance(),
* this method returns null if it cannot make use of the given ID.
*/
Transliterator* Transliterator::_createInstance(const UnicodeString& ID) {
UErrorCode status = U_ZERO_ERROR;
if (!cacheInitialized) {
initializeCache();
}
Mutex lock(&cacheMutex);
CacheEntry* entry = (CacheEntry*) uhash_get(cache, hash(ID));
TransliterationRuleData* data = 0;
if (entry == 0) {
return 0;
}
if (entry->entryType == CacheEntry::RBT_DATA) {
data = entry->u.data;
// Fall through to construct transliterator from cached Data object.
} else if (entry->entryType == CacheEntry::PROTOTYPE) {
return entry->u.prototype->clone();
} else {
// At this point entry type must be either RULE_BASED_PLACEHOLDER
// or REVERSE_RULE_BASED_PLACEHOLDER.
bool_t isReverse =
(entry->entryType ==
CacheEntry::REVERSE_RULE_BASED_PLACEHOLDER);
// We use the file name, taken from another resource bundle
// 2-d array at static init time, as a locale language. We're
// just using the locale mechanism to map through to a file
// name; this in no way represents an actual locale.
Locale fakeLocale(entry->rbFile);
ResourceBundle bundle(Transliterator::getDataDirectory(),
fakeLocale, status);
// Call RBT to parse the rules from the resource bundle
// We don't own the rules - 'rules' is an alias pointer to
// a string in the RB cache.
const UnicodeString* rules = bundle.getString(RB_RULE, status);
// If rules == 0 at this piont, or if the status indicates a
// failure, then we don't have any rules -- there is probably
// an installation error. The list in the root locale should
// correspond to all the installed transliterators; if it
// lists something that's not installed, we'll get a null
// pointer here.
if (rules != 0 && U_SUCCESS(status)) {
data = TransliterationRuleParser::parse(*rules, isReverse
? RuleBasedTransliterator::REVERSE
: RuleBasedTransliterator::FORWARD);
// Double check to see if someone has modified the entry
// since we last looked at it.
if (entry->entryType != CacheEntry::RBT_DATA) {
entry->entryType = CacheEntry::RBT_DATA;
entry->u.data = data;
} else {
// Oops! Another thread has updated this cache entry
// already to point to a data object. Discard the
// one we just created and use the one in the cache
// instead.
delete data;
data = entry->u.data;
}
}
}
if (data != 0) {
return new RuleBasedTransliterator(ID, data);
} else {
// We have a failure of some kind. Remove the ID from the
// cache so we don't keep trying. NOTE: This will throw off
// anyone who is, at the moment, trying to iterate over the
// available IDs. That's acceptable since we should never
// really get here except under installation, configuration,
// or unrecoverable run time memory failures.
_unregister(ID);
return 0;
}
}
/**
* Registers a instance <tt>obj</tt> of a subclass of
* <code>Transliterator</code> with the system. This object must
* implement the <tt>clone()</tt> method. When
* <tt>getInstance()</tt> is called with an ID string that is
* equal to <tt>obj.getID()</tt>, then <tt>obj.clone()</tt> is
* returned.
*
* @param obj an instance of subclass of
* <code>Transliterator</code> that defines <tt>clone()</tt>
* @see #getInstance
* @see #unregister
*/
void Transliterator::registerInstance(Transliterator* adoptedPrototype,
UErrorCode &status) {
if (!cacheInitialized) {
initializeCache();
}
Mutex lock(&cacheMutex);
_registerInstance(adoptedPrototype, status);
}
/**
* This internal method registers a prototype instance in the cache.
* The CALLER MUST MUTEX using cacheMutex before calling this method.
*/
void Transliterator::_registerInstance(Transliterator* adoptedPrototype,
UErrorCode &status) {
if (U_FAILURE(status)) {
return;
}
int32_t hashCode = hash(adoptedPrototype->getID());
// This needs explaining: The string reference that getID returns
// is to the ID data member of Transliterator. As long as the
// Transliterator object exists, this reference is valid, and in
// fact we can take its address and store it in IDS. No problem
// there. The only thing we have to be sure of is that before we
// remove the prototype (via unregister()), we remove the ID
// entry.
cacheIDs.addElement((void*) &adoptedPrototype->getID());
CacheEntry* entry = (CacheEntry*) uhash_get(cache, hashCode);
if (entry == 0) {
entry = new CacheEntry();
}
entry->adoptPrototype(adoptedPrototype);
uhash_putKey(cache, hashCode, entry, &status);
}
/**
* Unregisters a transliterator or class. This may be either
* a system transliterator or a user transliterator or class.
*
* @param ID the ID of the transliterator or class
* @see #registerInstance
*/
void Transliterator::unregister(const UnicodeString& ID) {
if (!cacheInitialized) {
initializeCache();
}
Mutex lock(&cacheMutex);
_unregister(ID);
}
/**
* Unregisters a transliterator or class. Internal method.
* Prerequisites: The cache must be initialized, and the
* caller must own the cacheMutex.
*/
void Transliterator::_unregister(const UnicodeString& ID) {
cacheIDs.removeElement((void*) &ID);
int32_t hc = hash(ID);
CacheEntry* entry = (CacheEntry*) uhash_get(cache, hc);
if (entry != 0) {
UErrorCode status = U_ZERO_ERROR;
uhash_remove(cache, hc, &status);
delete entry;
}
}
/**
* Vector of registered IDs.
*/
UVector Transliterator::cacheIDs;
/**
* Return the number of IDs currently registered with the system.
* To retrieve the actual IDs, call getAvailableID(i) with
* i from 0 to countAvailableIDs() - 1.
*/
int32_t Transliterator::countAvailableIDs() {
if (!cacheInitialized) {
initializeCache();
}
Mutex lock(&cacheMutex);
return cacheIDs.size();
}
/**
* Return the index-th available ID. index must be between 0
* and countAvailableIDs() - 1, inclusive. If index is out of
* range, the result of getAvailableID(0) is returned.
*/
const UnicodeString& Transliterator::getAvailableID(int32_t index) {
if (index < 0 || index >= cacheIDs.size()) {
index = 0;
}
if (!cacheInitialized) {
initializeCache();
}
Mutex lock(&cacheMutex);
return *(const UnicodeString*) cacheIDs[index];
}
/**
* Comparison function for UVector. Compares two UnicodeString
* objects given void* pointers to them.
*/
bool_t Transliterator::compareIDs(void* a, void* b) {
const UnicodeString* aa = (const UnicodeString*) a;
const UnicodeString* bb = (const UnicodeString*) b;
return *aa == *bb;
}
void Transliterator::initializeCache() {
// Lock first, check init boolean second
Mutex lock(&cacheMutex);
if (cacheInitialized) {
return;
}
UErrorCode status = U_ZERO_ERROR;
// Before looking for the resource, construct our cache.
// That way if the resource is absent, we will at least
// have a valid cache object.
cache = uhash_open(uhash_hashUString, &status);
cacheIDs.setComparer(compareIDs);
/* The following code is assuming an n x 3 table
* that looks like this:
*
* RuleBasedTransliteratorIDs {
* { "Latin-Arabic", "Arabic-Latin", "larabic" }
* { "KeyboardEscape-Latin1", "", "keyescl1" }
* ...
* }
*/
ResourceBundle bundle(Locale::getDataDirectory(),
Locale::getDefault(),
status);
int32_t rows, cols;
const UnicodeString** ruleBasedIDs =
bundle.get2dArray(RB_RULE_BASED_IDS, rows, cols, status);
if (U_SUCCESS(status) && (cols == 3)) {
for (int32_t i=0; i<rows; ++i) {
const UnicodeString* row = ruleBasedIDs[i];
for (int32_t col=0; col<2; ++col) {
if (row[col].length() > 0) {
CacheEntry* entry = new CacheEntry();
entry->entryType = (col == 0) ?
CacheEntry::RULE_BASED_PLACEHOLDER :
CacheEntry::REVERSE_RULE_BASED_PLACEHOLDER;
entry->rbFile = row[2];
uhash_putKey(cache, hash(row[col]), entry, &status);
/* It's okay to take the address of the string
* from the resource bundle under the assumption
* that the RB is caching these, and that they
* stay around forever. If this changes, what we
* need to do is change the id vector so that it
* owns its strings and create a copy here.
*/
cacheIDs.addElement((void*) &row[col]);
}
}
}
}
// Manually add prototypes that the system knows about to the
// cache. This is how new non-rule-based transliterators are
// added to the system.
status = U_ZERO_ERROR; // Reset status for following calls
_registerInstance(new HexToUnicodeTransliterator(), status);
_registerInstance(new UnicodeToHexTransliterator(), status);
cacheInitialized = TRUE;
}
Transliterator::CacheEntry::CacheEntry() {
u.prototype = 0;
entryType = NONE;
}
Transliterator::CacheEntry::~CacheEntry() {
if (entryType == PROTOTYPE) {
delete u.prototype;
}
}
void Transliterator::CacheEntry::adoptPrototype(Transliterator* adopted) {
if (entryType == PROTOTYPE) {
delete u.prototype;
}
entryType = PROTOTYPE;
u.prototype = adopted;
}