Check in the pristine copy of ICU 4.6...

icu46/source/i18n/unicode/colldata.h

+/*
+ ******************************************************************************
+ *   Copyright (C) 1996-2010, International Business Machines                 *
+ *   Corporation and others.  All Rights Reserved.                            *
+ ******************************************************************************
+ */
+
+/**
+ * \file 
+ * \brief C++ API: Collation data used to compute minLengthInChars.
+ * \internal
+ */
+ 
+#ifndef COLL_DATA_H
+#define COLL_DATA_H
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_COLLATION
+
+#include "unicode/uobject.h"
+#include "unicode/ucol.h"
+
+U_NAMESPACE_BEGIN
+
+/**
+ * The size of the internal buffer for the Collator's short description string.
+ * @internal ICU 4.0.1 technology preview
+ */
+#define KEY_BUFFER_SIZE 64
+
+ /**
+  * The size of the internal CE buffer in a <code>CEList</code> object
+  * @internal ICU 4.0.1 technology preview
+  */
+#define CELIST_BUFFER_SIZE 4
+
+/**
+ * \def INSTRUMENT_CELIST
+ * Define this to enable the <code>CEList</code> objects to collect
+ * statistics.
+ * @internal ICU 4.0.1 technology preview
+ */
+//#define INSTRUMENT_CELIST
+
+ /**
+  * The size of the initial list in a <code>StringList</code> object.
+  * @internal ICU 4.0.1 technology preview
+  */
+#define STRING_LIST_BUFFER_SIZE 16
+
+/**
+ * \def INSTRUMENT_STRING_LIST
+ * Define this to enable the <code>StringList</code> objects to
+ * collect statistics.
+ * @internal ICU 4.0.1 technology preview
+ */
+//#define INSTRUMENT_STRING_LIST
+
+ /**
+  * This object holds a list of CEs generated from a particular
+  * <code>UnicodeString</code>
+  *
+  * @internal ICU 4.0.1 technology preview
+  */
+class U_I18N_API CEList : public UObject
+{
+public:
+    /**
+     * Construct a <code>CEList</code> object.
+     *
+     * @param coll - the Collator used to collect the CEs.
+     * @param string - the string for which to collect the CEs.
+     * @param status - will be set if any errors occur. 
+     *
+     * Note: if on return, status is set to an error code,
+     * the only safe thing to do with this object is to call
+     * the destructor.
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    CEList(UCollator *coll, const UnicodeString &string, UErrorCode &status);
+
+    /**
+     * The destructor.
+     * @internal ICU 4.0.1 technology preview
+     */
+    ~CEList();
+
+    /**
+     * Return the number of CEs in the list.
+     *
+     * @return the number of CEs in the list.
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    int32_t size() const;
+
+    /**
+     * Get a particular CE from the list.
+     *
+     * @param index - the index of the CE to return
+     *
+     * @return the CE, or <code>0</code> if <code>index</code> is out of range
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    uint32_t get(int32_t index) const;
+
+    /**
+     * Check if the CEs in another <code>CEList</code> match the
+     * suffix of this list starting at a give offset.
+     *
+     * @param offset - the offset of the suffix
+     * @param other - the other <code>CEList</code>
+     *
+     * @return <code>TRUE</code> if the CEs match, <code>FALSE</code> otherwise.
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    UBool matchesAt(int32_t offset, const CEList *other) const; 
+
+    /**
+     * The index operator.
+     *
+     * @param index - the index
+     *
+     * @return a reference to the given CE in the list
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    uint32_t &operator[](int32_t index) const;
+
+    /**
+     * UObject glue...
+     * @internal ICU 4.0.1 technology preview
+     */
+    virtual UClassID getDynamicClassID() const;
+    /**
+     * UObject glue...
+     * @internal ICU 4.0.1 technology preview
+     */
+    static UClassID getStaticClassID();
+
+private:
+    void add(uint32_t ce, UErrorCode &status);
+
+    uint32_t ceBuffer[CELIST_BUFFER_SIZE];
+    uint32_t *ces;
+    int32_t listMax;
+    int32_t listSize;
+
+#ifdef INSTRUMENT_CELIST
+    static int32_t _active;
+    static int32_t _histogram[10];
+#endif
+};
+
+/**
+ * StringList
+ *
+ * This object holds a list of <code>UnicodeString</code> objects.
+ *
+ * @internal ICU 4.0.1 technology preview
+ */
+class U_I18N_API StringList : public UObject
+{
+public:
+    /**
+     * Construct an empty <code>StringList</code>
+     *
+     * @param status - will be set if any errors occur. 
+     *
+     * Note: if on return, status is set to an error code,
+     * the only safe thing to do with this object is to call
+     * the destructor.
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    StringList(UErrorCode &status);
+
+    /**
+     * The destructor.
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    ~StringList();
+
+    /**
+     * Add a string to the list.
+     *
+     * @param string - the string to add
+     * @param status - will be set if any errors occur. 
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    void add(const UnicodeString *string, UErrorCode &status);
+
+    /**
+     * Add an array of Unicode code points to the list.
+     *
+     * @param chars - the address of the array of code points
+     * @param count - the number of code points in the array
+     * @param status - will be set if any errors occur. 
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    void add(const UChar *chars, int32_t count, UErrorCode &status);
+
+    /**
+     * Get a particular string from the list.
+     *
+     * @param index - the index of the string
+     *
+     * @return a pointer to the <code>UnicodeString</code> or <code>NULL</code> 
+     *         if <code>index</code> is out of bounds.
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    const UnicodeString *get(int32_t index) const;
+
+    /**
+     * Get the number of stings in the list.
+     *
+     * @return the number of strings in the list.
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    int32_t size() const;
+
+    /**
+     * the UObject glue...
+     * @internal ICU 4.0.1 technology preview
+     */
+    virtual UClassID getDynamicClassID() const;
+    /**
+     * the UObject glue...
+     * @internal ICU 4.0.1 technology preview
+     */
+    static UClassID getStaticClassID();
+
+private:
+    UnicodeString *strings;
+    int32_t listMax;
+    int32_t listSize;
+
+#ifdef INSTRUMENT_STRING_LIST
+    static int32_t _lists;
+    static int32_t _strings;
+    static int32_t _histogram[101];
+#endif
+};
+
+/*
+ * Forward references to internal classes.
+ */
+class StringToCEsMap;
+class CEToStringsMap;
+class CollDataCache;
+
+/**
+ * CollData
+ *
+ * This class holds the Collator-specific data needed to
+ * compute the length of the shortest string that can
+ * generate a partcular list of CEs.
+ *
+ * <code>CollData</code> objects are quite expensive to compute. Because
+ * of this, they are cached. When you call <code>CollData::open</code> it
+ * returns a reference counted cached object. When you call <code>CollData::close</code>
+ * the reference count on the object is decremented but the object is not deleted.
+ *
+ * If you do not need to reuse any unreferenced objects in the cache, you can call
+ * <code>CollData::flushCollDataCache</code>. If you no longer need any <code>CollData</code>
+ * objects, you can call <code>CollData::freeCollDataCache</code>
+ *
+ * @internal ICU 4.0.1 technology preview
+ */
+class U_I18N_API CollData : public UObject
+{
+public:
+    /**
+     * Construct a <code>CollData</code> object.
+     *
+     * @param collator - the collator
+     * @param status - will be set if any errors occur. 
+     *
+     * @return the <code>CollData</code> object. You must call
+     *         <code>close</code> when you are done using the object.
+     *
+     * Note: if on return, status is set to an error code,
+     * the only safe thing to do with this object is to call
+     * <code>CollData::close</code>.
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    static CollData *open(UCollator *collator, UErrorCode &status);
+
+    /**
+     * Release a <code>CollData</code> object.
+     *
+     * @param collData - the object
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    static void close(CollData *collData);
+
+    /**
+     * Get the <code>UCollator</code> object used to create this object.
+     * The object returned may not be the exact object that was used to
+     * create this object, but it will have the same behavior.
+     * @internal ICU 4.0.1 technology preview
+     */
+    UCollator *getCollator() const;
+
+    /**
+     * Get a list of all the strings which generate a list
+     * of CEs starting with a given CE.
+     *
+     * @param ce - the CE
+     *
+     * return a <code>StringList</code> object containing all
+     *        the stirngs, or <code>NULL</code> if there are
+     *        no such strings.
+     *
+     * @internal ICU 4.0.1 technology preview.
+     */
+    const StringList *getStringList(int32_t ce) const;
+
+    /**
+     * Get a list of the CEs generated by a partcular stirng.
+     *
+     * @param string - the string
+     *
+     * @return a <code>CEList</code> object containt the CEs. You
+     *         must call <code>freeCEList</code> when you are finished
+     *         using the <code>CEList</code>/
+     *
+     * @internal ICU 4.0.1 technology preview.
+     */
+    const CEList *getCEList(const UnicodeString *string) const;
+
+    /**
+     * Release a <code>CEList</code> returned by <code>getCEList</code>.
+     *
+     * @param list - the <code>CEList</code> to free.
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    void freeCEList(const CEList *list);
+
+    /**
+     * Return the length of the shortest string that will generate
+     * the given list of CEs.
+     *
+     * @param ces - the CEs
+     * @param offset - the offset of the first CE in the list to use.
+     *
+     * @return the length of the shortest string.
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+    int32_t minLengthInChars(const CEList *ces, int32_t offset) const;
+
+ 
+    /**
+     * Return the length of the shortest string that will generate
+     * the given list of CEs.
+     *
+     * Note: the algorithm used to do this computation is recursive. To
+     * limit the amount of recursion, a "history" list is used to record
+     * the best answer starting at a particular offset in the list of CEs.
+     * If the same offset is visited again during the recursion, the answer
+     * in the history list is used.
+     *
+     * @param ces - the CEs
+     * @param offset - the offset of the first CE in the list to use.
+     * @param history - the history list. Must be at least as long as
+     *                 the number of cEs in the <code>CEList</code>
+     *
+     * @return the length of the shortest string.
+     *
+     * @internal ICU 4.0.1 technology preview
+     */
+   int32_t minLengthInChars(const CEList *ces, int32_t offset, int32_t *history) const;
+
+   /**
+    * UObject glue...
+    * @internal ICU 4.0.1 technology preview
+    */
+    virtual UClassID getDynamicClassID() const;
+   /**
+    * UObject glue...
+    * @internal ICU 4.0.1 technology preview
+    */
+    static UClassID getStaticClassID();
+
+    /**
+     * <code>CollData</code> objects are expensive to compute, and so
+     * may be cached. This routine will free the cached objects and delete
+     * the cache.
+     *
+     * WARNING: Don't call this until you are have called <code>close</code>
+     * for each <code>CollData</code> object that you have used. also,
+     * DO NOT call this if another thread may be calling <code>flushCollDataCache</code>
+     * at the same time.
+     *
+     * @internal 4.0.1 technology preview
+     */
+    static void freeCollDataCache();
+
+    /**
+     * <code>CollData</code> objects are expensive to compute, and so
+     * may be cached. This routine will remove any unused <code>CollData</code>
+     * objects from the cache.
+     *
+     * @internal 4.0.1 technology preview
+     */
+    static void flushCollDataCache();
+
+private:
+    friend class CollDataCache;
+    friend class CollDataCacheEntry;
+
+    CollData(UCollator *collator, char *cacheKey, int32_t cachekeyLength, UErrorCode &status);
+    ~CollData();
+
+    CollData();
+
+    static char *getCollatorKey(UCollator *collator, char *buffer, int32_t bufferLength);
+
+    static CollDataCache *getCollDataCache();
+
+    UCollator      *coll;
+    StringToCEsMap *charsToCEList;
+    CEToStringsMap *ceToCharsStartingWith;
+
+    char keyBuffer[KEY_BUFFER_SIZE];
+    char *key;
+
+    static CollDataCache *collDataCache;
+
+    uint32_t minHan;
+    uint32_t maxHan;
+
+    uint32_t jamoLimits[4];
+};
+
+U_NAMESPACE_END
+
+#endif // #if !UCONFIG_NO_COLLATION
+#endif // #ifndef COLL_DATA_H