Check in the pristine copy of ICU 4.6...

icu46/source/i18n/unicode/sortkey.h

+/*
+ *****************************************************************************
+ * 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 &lt; 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 &lt; 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