/* ***************************************************************************** * Copyright (C) 1996-2011, International Business Machines Corporation and others. * All Rights Reserved. ***************************************************************************** * * File sortkey.h * * Created by: Helena Shih * * Modification History: * * Date Name Description * * 6/20/97 helena Java class name change. * 8/18/97 helena Added internal API documentation. * 6/26/98 erm Changed to use byte arrays and memcmp. ***************************************************************************** */ #ifndef SORTKEY_H #define SORTKEY_H #include "unicode/utypes.h" /** * \file * \brief C++ API: Keys for comparing strings multiple times. */ #if !UCONFIG_NO_COLLATION #ifndef U_HIDE_DEPRECATED_API #include "unicode/uobject.h" #include "unicode/unistr.h" #include "unicode/coll.h" U_NAMESPACE_BEGIN /* forward declaration */ class RuleBasedCollator; /** * * Collation keys are generated by the Collator class. Use the CollationKey objects * instead of Collator to compare strings multiple times. A CollationKey * preprocesses the comparison information from the Collator object to * make the comparison faster. If you are not going to comparing strings * multiple times, then using the Collator object is generally faster, * since it only processes as much of the string as needed to make a * comparison. * <p> For example (with strength == tertiary) * <p>When comparing "Abernathy" to "Baggins-Smythworthy", Collator * only needs to process a couple of characters, while a comparison * with CollationKeys will process all of the characters. On the other hand, * if you are doing a sort of a number of fields, it is much faster to use * CollationKeys, since you will be comparing strings multiple times. * <p>Typical use of CollationKeys are in databases, where you store a CollationKey * in a hidden field, and use it for sorting or indexing. * * <p>Example of use: * <pre> * \code * UErrorCode success = U_ZERO_ERROR; * Collator* myCollator = Collator::createInstance(success); * CollationKey* keys = new CollationKey [3]; * myCollator->getCollationKey("Tom", keys[0], success ); * myCollator->getCollationKey("Dick", keys[1], success ); * myCollator->getCollationKey("Harry", keys[2], success ); * * // Inside body of sort routine, compare keys this way: * CollationKey tmp; * if(keys[0].compareTo( keys[1] ) > 0 ) { * tmp = keys[0]; keys[0] = keys[1]; keys[1] = tmp; * } * //... * \endcode * </pre> * <p>Because Collator::compare()'s algorithm is complex, it is faster to sort * long lists of words by retrieving collation keys with Collator::getCollationKey(). * You can then cache the collation keys and compare them using CollationKey::compareTo(). * <p> * <strong>Note:</strong> <code>Collator</code>s with different Locale, * CollationStrength and DecompositionMode settings will return different * CollationKeys for the same set of strings. Locales have specific * collation rules, and the way in which secondary and tertiary differences * are taken into account, for example, will result in different CollationKeys * for same strings. * <p> * @see Collator * @see RuleBasedCollator * @version 1.3 12/18/96 * @author Helena Shih * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ class U_I18N_API CollationKey : public UObject { public: /** * This creates an empty collation key based on the null string. An empty * collation key contains no sorting information. When comparing two empty * collation keys, the result is Collator::EQUAL. Comparing empty collation key * with non-empty collation key is always Collator::LESS. * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ CollationKey(); /** * Creates a collation key based on the collation key values. * @param values the collation key values * @param count number of collation key values, including trailing nulls. * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ CollationKey(const uint8_t* values, int32_t count); /** * Copy constructor. * @param other the object to be copied. * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ CollationKey(const CollationKey& other); /** * Sort key destructor. * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ virtual ~CollationKey(); /** * Assignment operator * @param other the object to be copied. * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ const CollationKey& operator=(const CollationKey& other); /** * Compare if two collation keys are the same. * @param source the collation key to compare to. * @return Returns true if two collation keys are equal, false otherwise. * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ UBool operator==(const CollationKey& source) const; /** * Compare if two collation keys are not the same. * @param source the collation key to compare to. * @return Returns TRUE if two collation keys are different, FALSE otherwise. * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ UBool operator!=(const CollationKey& source) const; /** * Test to see if the key is in an invalid state. The key will be in an * invalid state if it couldn't allocate memory for some operation. * @return Returns TRUE if the key is in an invalid, FALSE otherwise. * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ UBool isBogus(void) const; /** * Returns a pointer to the collation key values. The storage is owned * by the collation key and the pointer will become invalid if the key * is deleted. * @param count the output parameter of number of collation key values, * including any trailing nulls. * @return a pointer to the collation key values. * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ const uint8_t* getByteArray(int32_t& count) const; #ifdef U_USE_COLLATION_KEY_DEPRECATES /** * Extracts the collation key values into a new array. The caller owns * this storage and should free it. * @param count the output parameter of number of collation key values, * including any trailing nulls. * @obsolete ICU 2.6. Use getByteArray instead since this API will be removed in that release. */ uint8_t* toByteArray(int32_t& count) const; #endif /** * Convenience method which does a string(bit-wise) comparison of the * two collation keys. * @param target target collation key to be compared with * @return Returns Collator::LESS if sourceKey < targetKey, * Collator::GREATER if sourceKey > targetKey and Collator::EQUAL * otherwise. * @deprecated ICU 2.6 use the overload with error code */ Collator::EComparisonResult compareTo(const CollationKey& target) const; /** * Convenience method which does a string(bit-wise) comparison of the * two collation keys. * @param target target collation key to be compared with * @param status error code * @return Returns UCOL_LESS if sourceKey < targetKey, * UCOL_GREATER if sourceKey > targetKey and UCOL_EQUAL * otherwise. * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ UCollationResult compareTo(const CollationKey& target, UErrorCode &status) const; /** * Creates an integer that is unique to the collation key. NOTE: this * is not the same as String.hashCode. * <p>Example of use: * <pre> * . UErrorCode status = U_ZERO_ERROR; * . Collator *myCollation = Collator::createInstance(Locale::US, status); * . if (U_FAILURE(status)) return; * . CollationKey key1, key2; * . UErrorCode status1 = U_ZERO_ERROR, status2 = U_ZERO_ERROR; * . myCollation->getCollationKey("abc", key1, status1); * . if (U_FAILURE(status1)) { delete myCollation; return; } * . myCollation->getCollationKey("ABC", key2, status2); * . if (U_FAILURE(status2)) { delete myCollation; return; } * . // key1.hashCode() != key2.hashCode() * </pre> * @return the hash value based on the string's collation order. * @see UnicodeString#hashCode * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ int32_t hashCode(void) const; /** * ICU "poor man's RTTI", returns a UClassID for the actual class. * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ virtual UClassID getDynamicClassID() const; /** * ICU "poor man's RTTI", returns a UClassID for this class. * @deprecated ICU 2.8 Use Collator::getSortKey(...) instead */ static UClassID U_EXPORT2 getStaticClassID(); private: /** * Returns an array of the collation key values as 16-bit integers. * The caller owns the storage and must delete it. * @param values Output param of the collation key values. * @param capacity Size of the values array. * @param count output parameter of the number of collation key values * @return a pointer to an array of 16-bit collation key values. */ void adopt(uint8_t *values, int32_t capacity, int32_t count); /** * Set a new length for a new sort key in the existing fBytes. */ void setLength(int32_t newLength); /* * Creates a collation key with a string. */ /** * If this CollationKey has capacity less than newSize, * its internal capacity will be increased to newSize. * @param newSize minimum size this CollationKey has to have * @return this CollationKey */ CollationKey& ensureCapacity(int32_t newSize); /** * Set the CollationKey to a "bogus" or invalid state * @return this CollationKey */ CollationKey& setToBogus(void); /** * Resets this CollationKey to an empty state * @return this CollationKey */ CollationKey& reset(void); /** * Allow private access to RuleBasedCollator */ friend class RuleBasedCollator; /** * Bogus status */ UBool fBogus; /** * Size of fBytes used to store the sortkey. i.e. up till the * null-termination. */ int32_t fCount; /** * Full size of the fBytes */ int32_t fCapacity; /** * Unique hash value of this CollationKey */ int32_t fHashCode; /** * Array to store the sortkey */ uint8_t* fBytes; }; inline UBool CollationKey::operator!=(const CollationKey& other) const { return !(*this == other); } inline UBool CollationKey::isBogus() const { return fBogus; } inline const uint8_t* CollationKey::getByteArray(int32_t &count) const { count = fCount; return fBytes; } U_NAMESPACE_END #endif /* U_HIDE_DEPRECATED_API */ #endif /* #if !UCONFIG_NO_COLLATION */ #endif