| /* |
| ***************************************************************************************** |
| * * |
| * COPYRIGHT: * |
| * (C) Copyright Taligent, Inc., 1996 * |
| * (C) Copyright International Business Machines Corporation, 1996-1999 * |
| * Licensed Material - Program-Property of IBM - All Rights Reserved. * |
| * US Government Users Restricted Rights - Use, duplication, or disclosure * |
| * restricted by GSA ADP Schedule Contract with IBM Corp. * |
| * * |
| ***************************************************************************************** |
| */ |
| //=============================================================================== |
| // |
| // 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 "utypes.h" |
| #include "unistr.h" |
| #include "coll.h" |
| |
| |
| /** |
| * 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> |
| * . UErrorCode success = 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; |
| * . } |
| * . //... |
| * </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 |
| */ |
| class U_I18N_API CollationKey { |
| 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. |
| */ |
| 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. |
| * @see #createBits |
| */ |
| CollationKey(const uint8_t* values, |
| int32_t count); |
| |
| /** |
| * Copy constructor. |
| */ |
| CollationKey(const CollationKey& other); |
| /** |
| * Sort key destructor. |
| */ |
| ~CollationKey(); |
| |
| /** |
| * Assignment operator |
| */ |
| 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. |
| */ |
| bool_t 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. |
| */ |
| bool_t 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. |
| */ |
| bool_t 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. |
| */ |
| const uint8_t* getByteArray(int32_t& count) const; |
| |
| /** |
| * 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. |
| */ |
| uint8_t* toByteArray(int32_t& count) const; |
| |
| /** |
| * Convenience method which does a string(bit-wise) comparison of the |
| * two collation keys. |
| * @param sourceKey source collation key |
| * @param targetKey target collation key |
| * @return Returns Collator::LESS if sourceKey < targetKey, |
| * Collator::GREATER if sourceKey > targetKey and Collator::EQUAL |
| * otherwise. |
| */ |
| Collator::EComparisonResult compareTo(const CollationKey& target) 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 = ZERO_ERROR; |
| * . Collator *myCollation = Collator::createInstance(Locale::US, status); |
| * . if (FAILURE(status)) return; |
| * . CollationKey key1, key2; |
| * . UErrorCode status1 = ZERO_ERROR, status2 = ZERO_ERROR; |
| * . myCollation->getCollationKey("abc", key1, status1); |
| * . if (FAILURE(status1)) { delete myCollation; return; } |
| * . myCollation->getCollationKey("ABC", key2, status2); |
| * . if (FAILURE(status2)) { delete myCollation; return; } |
| * . // key1.hashCode() != key2.hashCode() |
| * </pre> |
| * @return the hash value based on the string's collation order. |
| * @see UnicodeString#hashCode |
| */ |
| int32_t hashCode(void) const; |
| |
| private: |
| /** |
| * Returns an array of the collation key values as 16-bit integers. |
| * The caller owns the storage and must delete it. |
| * @param size output parameter of the number of collation key values |
| * @return a pointer to an array of 16-bit collation key values. |
| */ |
| uint16_t* copyValues(int32_t &size) const; |
| |
| /* |
| * Creates a collation key with a string. |
| */ |
| CollationKey(const UnicodeString& value); |
| |
| int32_t storeBytes(int32_t cursor, uint32_t byteValue); |
| int32_t storeUnicodeString(int32_t cursor, const UnicodeString &value); |
| void reverseBytes(int32_t from, int32_t to); |
| CollationKey& ensureCapacity(int32_t newSize); |
| CollationKey& copyUnicodeString(const UnicodeString &value); |
| CollationKey& setToBogus(void); |
| CollationKey& reset(void); |
| |
| friend class RuleBasedCollator; |
| |
| static const int32_t kInvalidHashCode; |
| static const int32_t kEmptyHashCode; |
| |
| bool_t fBogus; |
| int32_t fCount; |
| int32_t fCapacity; |
| int32_t fHashCode; |
| uint8_t* fBytes; |
| }; |
| |
| inline bool_t |
| CollationKey::operator!=(const CollationKey& other) const |
| { |
| return !(*this == other); |
| } |
| |
| inline bool_t |
| CollationKey::isBogus() const |
| { |
| return fBogus; |
| } |
| |
| inline const uint8_t* |
| CollationKey::getByteArray(int32_t &count) const |
| { |
| count = fCount; |
| return fBytes; |
| } |
| |
| inline UTextOffset |
| CollationKey::storeBytes(UTextOffset cursor, uint32_t byteValue) |
| { |
| fBytes[cursor++] = (uint8_t) (byteValue >> 8); |
| fBytes[cursor++] = (uint8_t) byteValue; |
| |
| return cursor; |
| } |
| |
| #endif |
