/*
*****************************************************************************
* Copyright (C) 1996-2006, 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
#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 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 count);
/*
* 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 /* #if !UCONFIG_NO_COLLATION */
#endif