// © 2016 and later: Unicode, Inc. and others.

// License & terms of use: http://www.unicode.org/copyright.html

/*

*******************************************************************************

*   Copyright (C) 2010-2016, International Business Machines

*   Corporation and others.  All Rights Reserved.

*******************************************************************************

*   file name:  bytestriebuilder.h

*   encoding:   UTF-8

*   tab size:   8 (not used)

*   indentation:4

*

*   created on: 2010sep25

*   created by: Markus W. Scherer

*/

/**

 * \file

 * \brief C++ API: Builder for icu::BytesTrie

 */

#ifndef __BYTESTRIEBUILDER_H__

#define __BYTESTRIEBUILDER_H__

#include "unicode/utypes.h"

#if U_SHOW_CPLUSPLUS_API

#include "unicode/bytestrie.h"

#include "unicode/stringpiece.h"

#include "unicode/stringtriebuilder.h"

class BytesTrieTest;

U_NAMESPACE_BEGIN

class BytesTrieElement;

class CharString;

/**

 * Builder class for BytesTrie.

 *

 * This class is not intended for public subclassing.

 * @stable ICU 4.8

 */

class U_COMMON_API BytesTrieBuilder : public StringTrieBuilder {

public:

    /**

     * Constructs an empty builder.

     * @param errorCode Standard ICU error code.

     * @stable ICU 4.8

     */

    BytesTrieBuilder(UErrorCode &errorCode);

    /**

     * Destructor.

     * @stable ICU 4.8

     */

    virtual ~BytesTrieBuilder();

    /**

     * Adds a (byte sequence, value) pair.

     * The byte sequence must be unique.

     * The bytes will be copied; the builder does not keep

     * a reference to the input StringPiece or its data().

     * @param s The input byte sequence.

     * @param value The value associated with this byte sequence.

     * @param errorCode Standard ICU error code. Its input value must

     *                  pass the U_SUCCESS() test, or else the function returns

     *                  immediately. Check for U_FAILURE() on output or use with

     *                  function chaining. (See User Guide for details.)

     * @return *this

     * @stable ICU 4.8

     */

    BytesTrieBuilder &add(StringPiece s, int32_t value, UErrorCode &errorCode);

    /**

     * Builds a BytesTrie for the add()ed data.

     * Once built, no further data can be add()ed until clear() is called.

     *

     * A BytesTrie cannot be empty. At least one (byte sequence, value) pair

     * must have been add()ed.

     *

     * This method passes ownership of the builder's internal result array to the new trie object.

     * Another call to any build() variant will re-serialize the trie.

     * After clear() has been called, a new array will be used as well.

     * @param buildOption Build option, see UStringTrieBuildOption.

     * @param errorCode Standard ICU error code. Its input value must

     *                  pass the U_SUCCESS() test, or else the function returns

     *                  immediately. Check for U_FAILURE() on output or use with

     *                  function chaining. (See User Guide for details.)

     * @return A new BytesTrie for the add()ed data.

     * @stable ICU 4.8

     */

    BytesTrie *build(UStringTrieBuildOption buildOption, UErrorCode &errorCode);

    /**

     * Builds a BytesTrie for the add()ed data and byte-serializes it.

     * Once built, no further data can be add()ed until clear() is called.

     *

     * A BytesTrie cannot be empty. At least one (byte sequence, value) pair

     * must have been add()ed.

     *

     * Multiple calls to buildStringPiece() return StringPieces referring to the

     * builder's same byte array, without rebuilding.

     * If buildStringPiece() is called after build(), the trie will be

     * re-serialized into a new array (because build() passes on ownership).

     * If build() is called after buildStringPiece(), the trie object returned

     * by build() will become the owner of the underlying string for the

     * previously returned StringPiece.

     * After clear() has been called, a new array will be used as well.

     * @param buildOption Build option, see UStringTrieBuildOption.

     * @param errorCode Standard ICU error code. Its input value must

     *                  pass the U_SUCCESS() test, or else the function returns

     *                  immediately. Check for U_FAILURE() on output or use with

     *                  function chaining. (See User Guide for details.)

     * @return A StringPiece which refers to the byte-serialized BytesTrie for the add()ed data.

     * @stable ICU 4.8

     */

    StringPiece buildStringPiece(UStringTrieBuildOption buildOption, UErrorCode &errorCode);

    /**

     * Removes all (byte sequence, value) pairs.

     * New data can then be add()ed and a new trie can be built.

     * @return *this

     * @stable ICU 4.8

     */

    BytesTrieBuilder &clear();

private:

    friend class ::BytesTrieTest;

    BytesTrieBuilder(const BytesTrieBuilder &other);  // no copy constructor

    BytesTrieBuilder &operator=(const BytesTrieBuilder &other);  // no assignment operator

    void buildBytes(UStringTrieBuildOption buildOption, UErrorCode &errorCode);

    virtual int32_t getElementStringLength(int32_t i) const;

    virtual char16_t getElementUnit(int32_t i, int32_t byteIndex) const;

    virtual int32_t getElementValue(int32_t i) const;

    virtual int32_t getLimitOfLinearMatch(int32_t first, int32_t last, int32_t byteIndex) const;

    virtual int32_t countElementUnits(int32_t start, int32_t limit, int32_t byteIndex) const;

    virtual int32_t skipElementsBySomeUnits(int32_t i, int32_t byteIndex, int32_t count) const;

    virtual int32_t indexOfElementWithNextUnit(int32_t i, int32_t byteIndex, char16_t byte) const;

    virtual UBool matchNodesCanHaveValues() const { return false; }

    virtual int32_t getMaxBranchLinearSubNodeLength() const { return BytesTrie::kMaxBranchLinearSubNodeLength; }

    virtual int32_t getMinLinearMatch() const { return BytesTrie::kMinLinearMatch; }

    virtual int32_t getMaxLinearMatchLength() const { return BytesTrie::kMaxLinearMatchLength; }

    /**

     * @internal (private)

     */

    class BTLinearMatchNode : public LinearMatchNode {

    public:

        BTLinearMatchNode(const char *units, int32_t len, Node *nextNode);

        virtual bool operator==(const Node &other) const;

        virtual void write(StringTrieBuilder &builder);

    private:

        const char *s;

    };

    virtual Node *createLinearMatchNode(int32_t i, int32_t byteIndex, int32_t length,

                                        Node *nextNode) const;

    UBool ensureCapacity(int32_t length);

    virtual int32_t write(int32_t byte);

    int32_t write(const char *b, int32_t length);

    virtual int32_t writeElementUnits(int32_t i, int32_t byteIndex, int32_t length);

    virtual int32_t writeValueAndFinal(int32_t i, UBool isFinal);

    virtual int32_t writeValueAndType(UBool hasValue, int32_t value, int32_t node);

    virtual int32_t writeDeltaTo(int32_t jumpTarget);

    static int32_t internalEncodeDelta(int32_t i, char intBytes[]);

    CharString *strings;  // Pointer not object so we need not #include internal charstr.h.

    BytesTrieElement *elements;

    int32_t elementsCapacity;

    int32_t elementsLength;

    // Byte serialization of the trie.

    // Grows from the back: bytesLength measures from the end of the buffer!

    char *bytes;

    int32_t bytesCapacity;

    int32_t bytesLength;

};

U_NAMESPACE_END

#endif /* U_SHOW_CPLUSPLUS_API */

#endif  // __BYTESTRIEBUILDER_H__