/**
 * @file llsd.cpp
 * @brief LLSD flexible data system
 *
 * $LicenseInfo:firstyear=2005&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

// Must turn on conditional declarations in header file so definitions end up
// with proper linkage.
#define LLSD_DEBUG_INFO
#include "linden_common.h"
#include "llsd.h"

#include "llbase64.h"
#include "llerror.h"
#include "../llmath/llmath.h"
#include "llformat.h"
#include "llsdserialize.h"
#include "stringize.h"

#include <limits>

// Defend against a caller forcibly passing a negative number into an unsigned
// size_t index param
inline
bool was_negative(size_t i)
{
    return (i > std::numeric_limits<int>::max());
}
#define NEGATIVE_EXIT(i) if (was_negative(i)) return
#define NEGATIVE_RETURN(i, result) NEGATIVE_EXIT(i) (result)

#ifndef LL_RELEASE_FOR_DOWNLOAD
#define NAME_UNNAMED_NAMESPACE
#endif

#ifdef NAME_UNNAMED_NAMESPACE
namespace LLSDUnnamedNamespace
#else
namespace
#endif
{
    class ImplMap;
    class ImplArray;
}

#ifdef NAME_UNNAMED_NAMESPACE
using namespace LLSDUnnamedNamespace;
#endif

namespace llsd
{

// statics
S32 sLLSDAllocationCount = 0;
S32 sLLSDNetObjects = 0;

} // namespace llsd

#define ALLOC_LLSD_OBJECT           { llsd::sLLSDNetObjects++;  llsd::sLLSDAllocationCount++;   }
#define FREE_LLSD_OBJECT            { llsd::sLLSDNetObjects--;                                  }

class LLSD::Impl
    /**< This class is the abstract base class of the implementation of LLSD
         It provides the reference counting implementation, and the default
         implementation of most methods for most data types.  It also serves
         as a working implementation of the Undefined type.

    */
{
protected:
    Impl();

    enum StaticAllocationMarker { STATIC_USAGE_COUNT = 0xFFFFFFFF };
    Impl(StaticAllocationMarker);
        ///< This constructor is used for static objects and causes the
        //   suppresses adjusting the debugging counters when they are
        //   finally initialized.

    virtual ~Impl();

    bool shared() const                         { return (mUseCount > 1) && (mUseCount != STATIC_USAGE_COUNT); }

    U32 mUseCount;

public:
    static void reset(Impl*& var, Impl* impl);
        ///< safely set var to refer to the new impl (possibly shared)

    static void move(Impl*& var, Impl*& impl);
        ///< safely move impl from one object to another

    static       Impl& safe(      Impl*);
    static const Impl& safe(const Impl*);
        ///< since a NULL Impl* is used for undefined, this ensures there is
        //   always an object you call virtual member functions on

    virtual ImplMap& makeMap(Impl*& var);
    virtual ImplArray& makeArray(Impl*& var);
        ///< sure var is a modifiable, non-shared map or array

    virtual LLSD::Type type() const             { return LLSD::TypeUndefined; }

    static  void assignUndefined(LLSD::Impl*& var);
    static  void assign(LLSD::Impl*& var, const LLSD::Impl* other);

    virtual void assign(Impl*& var, LLSD::Boolean);
    virtual void assign(Impl*& var, LLSD::Integer);
    virtual void assign(Impl*& var, LLSD::Real);
    virtual void assign(Impl*& var, const char*);
    virtual void assign(Impl*& var, const LLSD::String&);
    virtual void assign(Impl*& var, const LLSD::UUID&);
    virtual void assign(Impl*& var, const LLSD::Date&);
    virtual void assign(Impl*& var, const LLSD::URI&);
    virtual void assign(Impl*& var, const LLSD::Binary&);
    virtual void assign(Impl*& var, LLSD::String&&);
    virtual void assign(Impl*& var, LLSD::UUID&&);
    virtual void assign(Impl*& var, LLSD::Date&&);
    virtual void assign(Impl*& var, LLSD::URI&&);
    virtual void assign(Impl*& var, LLSD::Binary&&);
        ///< If the receiver is the right type and unshared, these are simple
        //   data assignments, othewise the default implementation handless
        //   constructing the proper Impl subclass

    virtual Boolean asBoolean() const           { return false; }
    virtual Integer asInteger() const           { return 0; }
    virtual Real    asReal() const              { return 0.0; }
    virtual String  asString() const            { return std::string(); }
    virtual UUID    asUUID() const              { return LLUUID(); }
    virtual Date    asDate() const              { return LLDate(); }
    virtual URI     asURI() const               { return LLURI(); }
    virtual const Binary&   asBinary() const    { static const std::vector<U8> empty; return empty; }

    virtual const String& asStringRef() const { static const std::string empty; return empty; }

    virtual String asXMLRPCValue() const { return "<nil/>"; }

    virtual bool has(std::string_view) const      { return false; }
    virtual LLSD get(std::string_view) const      { return LLSD(); }
    virtual LLSD getKeys() const                { return LLSD::emptyArray(); }
    virtual void erase(const String&)           { }
    virtual const LLSD& ref(std::string_view) const{ return undef(); }

    virtual size_t size() const                 { return 0; }
    virtual LLSD get(size_t) const              { return LLSD(); }
    virtual void erase(size_t)                  { }
    virtual const LLSD& ref(size_t) const       { return undef(); }

    virtual LLSD::map_const_iterator beginMap() const { return endMap(); }
    virtual LLSD::map_const_iterator endMap() const { static const std::map<String, LLSD> empty; return empty.end(); }
    virtual LLSD::array_const_iterator beginArray() const { return endArray(); }
    virtual LLSD::array_const_iterator endArray() const { static const std::vector<LLSD> empty; return empty.end(); }

    virtual void dumpStats() const;
    virtual void calcStats(S32 type_counts[], S32 share_counts[]) const;
    // Container subclasses contain LLSD objects, rather than directly
    // containing Impl objects. This helper forwards through LLSD.
    void calcStats(const LLSD& llsd, S32 type_counts[], S32 share_counts[]) const
    {
        safe(llsd.impl).calcStats(type_counts, share_counts);
    }

    static const Impl& getImpl(const LLSD& llsd)    { return safe(llsd.impl); }
    static Impl& getImpl(LLSD& llsd)                { return safe(llsd.impl); }

    static const LLSD& undef();

    static U32 sAllocationCount;
    static U32 sOutstandingCount;
};

#ifdef NAME_UNNAMED_NAMESPACE
namespace LLSDUnnamedNamespace
#else
namespace
#endif
{
    template<LLSD::Type T, class Data, class DataRef = Data, class DataMove = Data>
    class ImplBase : public LLSD::Impl
        ///< This class handles most of the work for a subclass of Impl
        //   for a given simple data type.  Subclasses of this provide the
        //   conversion functions and a constructor.
    {
    protected:
        Data mValue;

        typedef ImplBase Base;

    public:
        ImplBase(DataRef value) : mValue(value) { }
        ImplBase(DataMove value) : mValue(std::move(value)) { }

        virtual LLSD::Type type() const { return T; }

        using LLSD::Impl::assign; // Unhiding base class virtuals...
        virtual void assign(LLSD::Impl*& var, DataRef value) {
            if (shared())
            {
                Impl::assign(var, value);
            }
            else
            {
                mValue = value;
            }
        }
        virtual void assign(LLSD::Impl*& var, DataMove value) {
            if (shared())
            {
                Impl::assign(var, std::move(value));
            }
            else
            {
                mValue = std::move(value);
            }
        }
    };


    class ImplBoolean final
        : public ImplBase<LLSD::TypeBoolean, LLSD::Boolean, LLSD::Boolean, LLSD::Boolean&&>
    {
    public:
        ImplBoolean(LLSD::Boolean v) : Base(v) { }

        virtual LLSD::Boolean   asBoolean() const   { return mValue; }
        virtual LLSD::Integer   asInteger() const   { return mValue ? 1 : 0; }
        virtual LLSD::Real      asReal() const      { return mValue ? 1 : 0; }
        virtual LLSD::String    asString() const;

        virtual LLSD::String asXMLRPCValue() const { return mValue ? "<boolean>1</boolean>" : "<boolean>0</boolean>"; }
    };

    LLSD::String ImplBoolean::asString() const
        // *NOTE: The reason that false is not converted to "false" is
        // because that would break roundtripping,
        // e.g. LLSD(false).asString().asBoolean().  There are many
        // reasons for wanting LLSD("false").asBoolean() == true, such
        // as "everything else seems to work that way".
        { return mValue ? "true" : ""; }


    class ImplInteger final
        : public ImplBase<LLSD::TypeInteger, LLSD::Integer, LLSD::Integer, LLSD::Integer&&>
    {
    public:
        ImplInteger(LLSD::Integer v) : Base(v) { }

        virtual LLSD::Boolean   asBoolean() const   { return mValue != 0; }
        virtual LLSD::Integer   asInteger() const   { return mValue; }
        virtual LLSD::Real      asReal() const      { return mValue; }
        virtual LLSD::String    asString() const;

        virtual LLSD::String asXMLRPCValue() const { return "<int>" + std::to_string(mValue) + "</int>"; }
    };

    LLSD::String ImplInteger::asString() const
        { return llformat("%d", mValue); }


    class ImplReal final
        : public ImplBase<LLSD::TypeReal, LLSD::Real, LLSD::Real, LLSD::Real&&>
    {
    public:
        ImplReal(LLSD::Real v) : Base(v) { }

        virtual LLSD::Boolean   asBoolean() const;
        virtual LLSD::Integer   asInteger() const;
        virtual LLSD::Real      asReal() const      { return mValue; }
        virtual LLSD::String    asString() const;

        virtual LLSD::String asXMLRPCValue() const { return "<double>" + std::to_string(mValue) + "</double>"; }
    };

    LLSD::Boolean ImplReal::asBoolean() const
        { return !llisnan(mValue)  &&  mValue != 0.0; }

    LLSD::Integer ImplReal::asInteger() const
        { return !llisnan(mValue) ? (LLSD::Integer)mValue : 0; }

    LLSD::String ImplReal::asString() const
        { return llformat("%lg", mValue); }


    class ImplString final
        : public ImplBase<LLSD::TypeString, LLSD::String, const LLSD::String&, LLSD::String&&>
    {
    public:
        ImplString(const LLSD::String& v) : Base(v) { }
        ImplString(LLSD::String&& v) : Base(std::move(v)) {}

        virtual LLSD::Boolean   asBoolean() const   { return !mValue.empty(); }
        virtual LLSD::Integer   asInteger() const;
        virtual LLSD::Real      asReal() const;
        virtual LLSD::String    asString() const    { return mValue; }
        virtual LLSD::UUID      asUUID() const  { return LLUUID(mValue); }
        virtual LLSD::Date      asDate() const  { return LLDate(mValue); }
        virtual LLSD::URI       asURI() const   { return LLURI(mValue); }
        virtual size_t          size() const    { return mValue.size(); }
        virtual const LLSD::String& asStringRef() const { return mValue; }

        virtual LLSD::String asXMLRPCValue() const { return "<string>" + LLStringFn::xml_encode(mValue) + "</string>"; }

        using LLSD::Impl::assign; // Unhiding base class virtuals...
        virtual void assign(LLSD::Impl*& var, const char* value)
        {
            if (shared())
            {
                Impl::assign(var, value);
            }
            else
            {
                mValue = value;
            }
        }
    };

    LLSD::Integer ImplString::asInteger() const
    {
        // This must treat "1.23" not as an error, but as a number, which is
        // then truncated down to an integer.  Hence, this code doesn't call
        // std::istringstream::operator>>(int&), which would not consume the
        // ".23" portion.

        return (int)asReal();
    }

    LLSD::Real ImplString::asReal() const
    {
        F64 v = 0.0;
        std::istringstream i_stream(mValue);
        i_stream >> v;

        // we would probably like to ignore all trailing whitespace as
        // well, but for now, simply eat the next character, and make
        // sure we reached the end of the string.
        // *NOTE: gcc 2.95 does not generate an eof() event on the
        // stream operation above, so we manually get here to force it
        // across platforms.
        int c = i_stream.get();
        return ((EOF ==c) ? v : 0.0);
    }


    class ImplUUID final
        : public ImplBase<LLSD::TypeUUID, LLSD::UUID, const LLSD::UUID&, LLSD::UUID&&>
    {
    public:
        ImplUUID(const LLSD::UUID& v) : Base(v) { }
        ImplUUID(LLSD::UUID&& v) : Base(std::move(v)) { }

        virtual LLSD::String    asString() const{ return mValue.asString(); }
        virtual LLSD::UUID      asUUID() const  { return mValue; }

        virtual LLSD::String asXMLRPCValue() const { return "<string>" + mValue.asString() + "</string>"; }
    };


    class ImplDate final
        : public ImplBase<LLSD::TypeDate, LLSD::Date, const LLSD::Date&, LLSD::Date&&>
    {
    public:
        ImplDate(const LLSD::Date& v)
            : ImplBase(v)
            { }

        ImplDate(LLSD::Date&& v)
            : ImplBase(std::move(v))
        { }

        virtual LLSD::Integer asInteger() const
        {
            return (LLSD::Integer)(mValue.secondsSinceEpoch());
        }
        virtual LLSD::Real asReal() const
        {
            return mValue.secondsSinceEpoch();
        }
        virtual LLSD::String    asString() const{ return mValue.asString(); }
        virtual LLSD::Date      asDate() const  { return mValue; }

        virtual LLSD::String asXMLRPCValue() const { return "<dateTime.iso8601>" + mValue.toHTTPDateString("%FT%T") + "</dateTime.iso8601>"; }
    };


    class ImplURI final
        : public ImplBase<LLSD::TypeURI, LLSD::URI, const LLSD::URI&, LLSD::URI&&>
    {
    public:
        ImplURI(const LLSD::URI& v) : Base(v) { }
        ImplURI(LLSD::URI&& v) : Base(std::move(v)) { }

        virtual LLSD::String    asString() const{ return mValue.asString(); }
        virtual LLSD::URI       asURI() const   { return mValue; }

        virtual LLSD::String asXMLRPCValue() const { return "<string>" + LLStringFn::xml_encode(mValue.asString()) + "</string>"; }
    };


    class ImplBinary final
        : public ImplBase<LLSD::TypeBinary, LLSD::Binary, const LLSD::Binary&, LLSD::Binary&&>
    {
    public:
        ImplBinary(const LLSD::Binary& v) : Base(v) { }
        ImplBinary(LLSD::Binary&& v) : Base(std::move(v)) { }

        virtual const LLSD::Binary& asBinary() const{ return mValue; }

        virtual LLSD::String asXMLRPCValue() const { return "<base64>" + LLBase64::encode(mValue.data(), mValue.size()) + "</base64>"; }
    };


    class ImplMap final : public LLSD::Impl
    {
    private:
        typedef std::map<LLSD::String, LLSD, std::less<>> DataMap;

        DataMap mData;

    protected:
        ImplMap(const DataMap& data) : mData(data) { }

    public:
        ImplMap() { }

        virtual ImplMap& makeMap(LLSD::Impl*&);

        virtual LLSD::Type type() const { return LLSD::TypeMap; }

        virtual LLSD::Boolean asBoolean() const { return !mData.empty(); }

        virtual LLSD::String asXMLRPCValue() const
        {
            std::ostringstream os;
            os << "<struct>";
            for (const auto& it : mData)
            {
                os << "<member><name>" << LLStringFn::xml_encode(it.first) << "</name>"
                    << it.second.asXMLRPCValue() << "</member>";
            }
            os << "</struct>";
            return os.str();
        }

        virtual bool has(std::string_view) const;

        using LLSD::Impl::get; // Unhiding get(size_t)
        using LLSD::Impl::erase; // Unhiding erase(size_t)
        using LLSD::Impl::ref; // Unhiding ref(size_t)
        virtual LLSD get(std::string_view) const;
        virtual LLSD getKeys() const;
        void insert(std::string_view k, const LLSD& v);
        virtual void erase(const LLSD::String&);
                      LLSD& ref(std::string_view);
        virtual const LLSD& ref(std::string_view) const;

        virtual size_t size() const { return mData.size(); }

        LLSD::map_iterator beginMap() { return mData.begin(); }
        LLSD::map_iterator endMap() { return mData.end(); }
        virtual LLSD::map_const_iterator beginMap() const { return mData.begin(); }
        virtual LLSD::map_const_iterator endMap() const { return mData.end(); }

        virtual void dumpStats() const;
        virtual void calcStats(S32 type_counts[], S32 share_counts[]) const;
    };

    ImplMap& ImplMap::makeMap(LLSD::Impl*& var)
    {
        LL_PROFILE_ZONE_SCOPED_CATEGORY_LLSD;
        if (shared())
        {
            ImplMap* i = new ImplMap(mData);
            Impl::assign(var, i);
            return *i;
        }
        else
        {
            return *this;
        }
    }

    bool ImplMap::has(const std::string_view k) const
    {
        LL_PROFILE_ZONE_SCOPED_CATEGORY_LLSD;
        DataMap::const_iterator i = mData.find(k);
        return i != mData.end();
    }

    LLSD ImplMap::get(const std::string_view k) const
    {
        LL_PROFILE_ZONE_SCOPED_CATEGORY_LLSD;
        DataMap::const_iterator i = mData.find(k);
        return (i != mData.end()) ? i->second : LLSD();
    }

    LLSD ImplMap::getKeys() const
    {
        LL_PROFILE_ZONE_SCOPED_CATEGORY_LLSD;
        LLSD keys = LLSD::emptyArray();
        DataMap::const_iterator iter = mData.begin();
        while (iter != mData.end())
        {
            keys.append((*iter).first);
            iter++;
        }
        return keys;
    }

    void ImplMap::insert(std::string_view k, const LLSD& v)
    {
        LL_PROFILE_ZONE_SCOPED_CATEGORY_LLSD;
        mData.emplace(k, v);
    }

    void ImplMap::erase(const LLSD::String& k)
    {
        LL_PROFILE_ZONE_SCOPED_CATEGORY_LLSD;
        mData.erase(k);
    }

    LLSD& ImplMap::ref(std::string_view k)
    {
        DataMap::iterator i = mData.lower_bound(k);
        if (i == mData.end() || mData.key_comp()(k, i->first))
        {
            return mData.emplace_hint(i, std::make_pair(k, LLSD()))->second;
        }

        return i->second;
    }

    const LLSD& ImplMap::ref(std::string_view k) const
    {
        DataMap::const_iterator i = mData.lower_bound(k);
        if (i == mData.end() || mData.key_comp()(k, i->first))
        {
            return undef();
        }

        return i->second;
    }

    void ImplMap::dumpStats() const
    {
        std::cout << "Map size: " << mData.size() << std::endl;

        std::cout << "LLSD Net Objects: " << llsd::sLLSDNetObjects << std::endl;
        std::cout << "LLSD allocations: " << llsd::sLLSDAllocationCount << std::endl;

        std::cout << "LLSD::Impl Net Objects: " << sOutstandingCount << std::endl;
        std::cout << "LLSD::Impl allocations: " << sAllocationCount << std::endl;

        Impl::dumpStats();
    }

    void ImplMap::calcStats(S32 type_counts[], S32 share_counts[]) const
    {
        LLSD::map_const_iterator iter = beginMap();
        while (iter != endMap())
        {
            //std::cout << "  " << (*iter).first << ": " << (*iter).second << std::endl;
            Impl::calcStats((*iter).second, type_counts, share_counts);
            ++iter;
        }

        // Add in the values for this map
        Impl::calcStats(type_counts, share_counts);
    }


    class ImplArray : public LLSD::Impl
    {
    private:
        typedef std::vector<LLSD> DataVector;

        DataVector mData;

    protected:
        ImplArray(const DataVector& data) : mData(data) { }

    public:
        ImplArray() { }

        virtual ImplArray& makeArray(Impl*&);

        virtual LLSD::Type type() const { return LLSD::TypeArray; }

        virtual LLSD::Boolean asBoolean() const { return !mData.empty(); }

        virtual LLSD::String asXMLRPCValue() const
        {
            std::ostringstream os;
            os << "<array><data>";
            for (const auto& it : mData)
            {
                os << it.asXMLRPCValue();
            }
            os << "</data></array>";
            return os.str();
        }

        using LLSD::Impl::get; // Unhiding get(LLSD::String)
        using LLSD::Impl::erase; // Unhiding erase(LLSD::String)
        using LLSD::Impl::ref; // Unhiding ref(LLSD::String)
        virtual size_t size() const;
        virtual LLSD get(size_t) const;
                void set(size_t, const LLSD&);
                void insert(size_t, const LLSD&);
                LLSD& append(const LLSD&);
        virtual void erase(size_t);
                      LLSD& ref(size_t);
        virtual const LLSD& ref(size_t) const;

        LLSD::array_iterator beginArray() { return mData.begin(); }
        LLSD::array_iterator endArray() { return mData.end(); }
        LLSD::reverse_array_iterator rbeginArray() { return mData.rbegin(); }
        LLSD::reverse_array_iterator rendArray() { return mData.rend(); }
        virtual LLSD::array_const_iterator beginArray() const { return mData.begin(); }
        virtual LLSD::array_const_iterator endArray() const { return mData.end(); }

        virtual void calcStats(S32 type_counts[], S32 share_counts[]) const;
    };

    ImplArray& ImplArray::makeArray(Impl*& var)
    {
        if (shared())
        {
            ImplArray* i = new ImplArray(mData);
            Impl::assign(var, i);
            return *i;
        }
        else
        {
            return *this;
        }
    }

    size_t ImplArray::size() const      { return mData.size(); }

    LLSD ImplArray::get(size_t i) const
    {
        NEGATIVE_RETURN(i, LLSD());
        DataVector::size_type index = i;

        return (index < mData.size()) ? mData[index] : LLSD();
    }

    void ImplArray::set(size_t i, const LLSD& v)
    {
        NEGATIVE_EXIT(i);
        DataVector::size_type index = i;

        if (index >= mData.size())
        {
            mData.resize(index + 1);
        }

        mData[index] = v;
    }

    void ImplArray::insert(size_t i, const LLSD& v)
    {
        NEGATIVE_EXIT(i);
        DataVector::size_type index = i;

        if (index >= mData.size())  // tbd - sanity check limit for index ?
        {
            mData.resize(index + 1);
        }

        mData.insert(mData.begin() + index, v);
    }

    LLSD& ImplArray::append(const LLSD& v)
    {
        mData.push_back(v);
        return mData.back();
    }

    void ImplArray::erase(size_t i)
    {
        NEGATIVE_EXIT(i);
        DataVector::size_type index = i;

        if (index < mData.size())
        {
            mData.erase(mData.begin() + index);
        }
    }

    LLSD& ImplArray::ref(size_t i)
    {
        DataVector::size_type index = was_negative(i)? 0 : i;

        if (index >= mData.size())
        {
            mData.resize(index + 1);
        }

        return mData[index];
    }

    const LLSD& ImplArray::ref(size_t i) const
    {
        NEGATIVE_RETURN(i, undef());
        DataVector::size_type index = i;

        if (index >= mData.size())
        {
            return undef();
        }

        return mData[index];
    }

    void ImplArray::calcStats(S32 type_counts[], S32 share_counts[]) const
    {
        LLSD::array_const_iterator iter = beginArray();
        while (iter != endArray())
        {   // Add values for all items held in the array
            Impl::calcStats((*iter), type_counts, share_counts);
            ++iter;
        }

        // Add in the values for this array
        Impl::calcStats(type_counts, share_counts);
    }
}

LLSD::Impl::Impl()
    : mUseCount(0)
{
    ++sAllocationCount;
    ++sOutstandingCount;
}

LLSD::Impl::Impl(StaticAllocationMarker)
    : mUseCount(0)
{
}

LLSD::Impl::~Impl()
{
    --sOutstandingCount;
}

void LLSD::Impl::reset(Impl*& var, Impl* impl)
{
    if (impl && impl->mUseCount != STATIC_USAGE_COUNT)
    {
        ++impl->mUseCount;
    }
    if (var  &&  var->mUseCount != STATIC_USAGE_COUNT && --var->mUseCount == 0)
    {
        delete var;
    }
    var = impl;
}

void LLSD::Impl::move(Impl*& var, Impl*& impl)
{
    if (var && var->mUseCount != STATIC_USAGE_COUNT && --var->mUseCount == 0)
    {
        delete var; // destroy var if usage falls to 0 and not static
    }
    var = impl; // Steal impl to var without incrementing use since this is a move
    impl = nullptr; // null out old-impl pointer
}

LLSD::Impl& LLSD::Impl::safe(Impl* impl)
{
    static Impl theUndefined(STATIC_USAGE_COUNT);
    return impl ? *impl : theUndefined;
}

const LLSD::Impl& LLSD::Impl::safe(const Impl* impl)
{
    static Impl theUndefined(STATIC_USAGE_COUNT);
    return impl ? *impl : theUndefined;
}

ImplMap& LLSD::Impl::makeMap(Impl*& var)
{
    LL_PROFILE_ZONE_SCOPED_CATEGORY_LLSD;
    ImplMap* im = new ImplMap;
    reset(var, im);
    return *im;
}

ImplArray& LLSD::Impl::makeArray(Impl*& var)
{
    ImplArray* ia = new ImplArray;
    reset(var, ia);
    return *ia;
}


void LLSD::Impl::assign(Impl*& var, const Impl* other)
{
    reset(var, const_cast<Impl*>(other));
}

void LLSD::Impl::assignUndefined(Impl*& var)
{
    reset(var, 0);
}

void LLSD::Impl::assign(Impl*& var, LLSD::Boolean v)
{
    reset(var, new ImplBoolean(v));
}

void LLSD::Impl::assign(Impl*& var, LLSD::Integer v)
{
    reset(var, new ImplInteger(v));
}

void LLSD::Impl::assign(Impl*& var, LLSD::Real v)
{
    reset(var, new ImplReal(v));
}

void LLSD::Impl::assign(Impl*& var, const char* v)
{
    reset(var, new ImplString(v));
}

void LLSD::Impl::assign(Impl*& var, const LLSD::String& v)
{
    reset(var, new ImplString(v));
}

void LLSD::Impl::assign(Impl*& var, const LLSD::UUID& v)
{
    reset(var, new ImplUUID(v));
}

void LLSD::Impl::assign(Impl*& var, const LLSD::Date& v)
{
    reset(var, new ImplDate(v));
}

void LLSD::Impl::assign(Impl*& var, const LLSD::URI& v)
{
    reset(var, new ImplURI(v));
}

void LLSD::Impl::assign(Impl*& var, const LLSD::Binary& v)
{
    reset(var, new ImplBinary(v));
}

void LLSD::Impl::assign(Impl*& var, LLSD::String&& v)
{
    reset(var, new ImplString(std::move(v)));
}

void LLSD::Impl::assign(Impl*& var, LLSD::UUID&& v)
{
    reset(var, new ImplUUID(std::move(v)));
}

void LLSD::Impl::assign(Impl*& var, LLSD::Date&& v)
{
    reset(var, new ImplDate(std::move(v)));
}

void LLSD::Impl::assign(Impl*& var, LLSD::URI&& v)
{
    reset(var, new ImplURI(std::move(v)));
}

void LLSD::Impl::assign(Impl*& var, LLSD::Binary&& v)
{
    reset(var, new ImplBinary(std::move(v)));
}


const LLSD& LLSD::Impl::undef()
{
    static const LLSD immutableUndefined;
    return immutableUndefined;
}

void LLSD::Impl::dumpStats() const
{
    S32 type_counts[LLSD::TypeLLSDNumTypes + 1];
    memset(&type_counts, 0, sizeof(type_counts));

    S32 share_counts[LLSD::TypeLLSDNumTypes + 1];
    memset(&share_counts, 0, sizeof(share_counts));

    // Add info from all the values this object has
    calcStats(type_counts, share_counts);

    S32 type_index = LLSD::TypeLLSDTypeBegin;
    while (type_index != LLSD::TypeLLSDTypeEnd)
    {
        std::cout << LLSD::typeString((LLSD::Type)type_index) << " type "
            << type_counts[type_index] << " objects, "
            << share_counts[type_index] << " shared"
            << std::endl;
        type_index++;
    }
}


void LLSD::Impl::calcStats(S32 type_counts[], S32 share_counts[]) const
{
    S32 tp = S32(type());
    if (0 <= tp && tp < LLSD::TypeLLSDNumTypes)
    {
        type_counts[tp]++;
        if (shared())
        {
            share_counts[tp]++;
        }
    }
}


U32 LLSD::Impl::sAllocationCount = 0;
U32 LLSD::Impl::sOutstandingCount = 0;



#ifdef NAME_UNNAMED_NAMESPACE
namespace LLSDUnnamedNamespace
#else
namespace
#endif
{
    inline LLSD::Impl& safe(LLSD::Impl* impl)
        { return LLSD::Impl::safe(impl); }

    inline ImplMap& makeMap(LLSD::Impl*& var)
        { return safe(var).makeMap(var); }

    inline ImplArray& makeArray(LLSD::Impl*& var)
        { return safe(var).makeArray(var); }
}


LLSD::LLSD() : impl(0)                  { ALLOC_LLSD_OBJECT; }
LLSD::~LLSD()                           { FREE_LLSD_OBJECT; Impl::reset(impl, 0); }

LLSD::LLSD(const LLSD& other) : impl(0) { ALLOC_LLSD_OBJECT;  assign(other); }
void LLSD::assign(const LLSD& other)    { Impl::assign(impl, other.impl); }

LLSD::LLSD(LLSD&& other) noexcept : impl(nullptr) { ALLOC_LLSD_OBJECT;  Impl::move(impl, other.impl); }
void  LLSD::assign(LLSD&& other) { Impl::move(impl, other.impl); }
LLSD& LLSD::operator=(LLSD&& other) noexcept { Impl::move(impl, other.impl); return *this; }

void LLSD::clear()                      { Impl::assignUndefined(impl); }

LLSD::Type LLSD::type() const           { return safe(impl).type(); }

bool LLSD::isEmpty() const
{
    switch (type())
    {
    case TypeUndefined:
        return true; // Always empty
    case TypeBinary:
        return !asBoolean(); // Empty when default
    case TypeInteger:
        return !asInteger(); // Empty when default
    case TypeReal:
        return !asReal(); // Empty when default
    case TypeString:
    case TypeURI:
        return asString().empty(); // Empty natively
    case TypeArray:
    case TypeMap:
        return !size(); // Empty natively
    default:;
    }
    // All other value types (TypeDate) don't have default values so can't be empty
    return false;
}


// Scalar Constructors
LLSD::LLSD(Boolean v) : impl(0)         { ALLOC_LLSD_OBJECT;    assign(v); }
LLSD::LLSD(Integer v) : impl(0)         { ALLOC_LLSD_OBJECT;    assign(v); }
LLSD::LLSD(Real v) : impl(0)            { ALLOC_LLSD_OBJECT;    assign(v); }
LLSD::LLSD(const UUID& v) : impl(0)     { ALLOC_LLSD_OBJECT;    assign(v); }
LLSD::LLSD(const String& v) : impl(0)   { ALLOC_LLSD_OBJECT;    assign(v); }
LLSD::LLSD(const Date& v) : impl(0)     { ALLOC_LLSD_OBJECT;    assign(v); }
LLSD::LLSD(const URI& v) : impl(0)      { ALLOC_LLSD_OBJECT;    assign(v); }
LLSD::LLSD(const Binary& v) : impl(0)   { ALLOC_LLSD_OBJECT;    assign(v); }
LLSD::LLSD(UUID&& v) : impl(0)          { ALLOC_LLSD_OBJECT;    assign(std::move(v)); }
LLSD::LLSD(String&& v) : impl(0)        { ALLOC_LLSD_OBJECT;    assign(std::move(v)); }
LLSD::LLSD(Date&& v) : impl(0)          { ALLOC_LLSD_OBJECT;    assign(std::move(v)); }
LLSD::LLSD(URI&& v) : impl(0)           { ALLOC_LLSD_OBJECT;    assign(std::move(v)); }
LLSD::LLSD(Binary&& v) : impl(0)        { ALLOC_LLSD_OBJECT;    assign(std::move(v)); }

// Scalar Assignment
void LLSD::assign(Boolean v)            { safe(impl).assign(impl, v); }
void LLSD::assign(Integer v)            { safe(impl).assign(impl, v); }
void LLSD::assign(Real v)               { safe(impl).assign(impl, v); }
void LLSD::assign(const String& v)      { safe(impl).assign(impl, v); }
void LLSD::assign(const UUID& v)        { safe(impl).assign(impl, v); }
void LLSD::assign(const Date& v)        { safe(impl).assign(impl, v); }
void LLSD::assign(const URI& v)         { safe(impl).assign(impl, v); }
void LLSD::assign(const Binary& v)      { safe(impl).assign(impl, v); }
void LLSD::assign(String&& v)           { safe(impl).assign(impl, std::move(v)); }
void LLSD::assign(UUID&& v)             { safe(impl).assign(impl, std::move(v)); }
void LLSD::assign(Date&& v)             { safe(impl).assign(impl, std::move(v)); }
void LLSD::assign(URI&& v)              { safe(impl).assign(impl, std::move(v)); }
void LLSD::assign(Binary&& v)           { safe(impl).assign(impl, std::move(v)); }

// Scalar Accessors
LLSD::Boolean   LLSD::asBoolean() const { return safe(impl).asBoolean(); }
LLSD::Integer   LLSD::asInteger() const { return safe(impl).asInteger(); }
LLSD::Real      LLSD::asReal() const    { return safe(impl).asReal(); }
LLSD::String    LLSD::asString() const  { return safe(impl).asString(); }
LLSD::UUID      LLSD::asUUID() const    { return safe(impl).asUUID(); }
LLSD::Date      LLSD::asDate() const    { return safe(impl).asDate(); }
LLSD::URI       LLSD::asURI() const     { return safe(impl).asURI(); }
const LLSD::Binary& LLSD::asBinary() const  { return safe(impl).asBinary(); }

const LLSD::String& LLSD::asStringRef() const { return safe(impl).asStringRef(); }

LLSD::String LLSD::asXMLRPCValue() const { return "<value>" + safe(impl).asXMLRPCValue() + "</value>"; }

// const char * helpers
LLSD::LLSD(const char* v) : impl(0)     { ALLOC_LLSD_OBJECT;    assign(v); }
void LLSD::assign(const char* v)
{
    if(v) safe(impl).assign(impl, v);
    else assign(std::string());
}


LLSD LLSD::emptyMap()
{
    LLSD v;
    makeMap(v.impl);
    return v;
}

bool LLSD::has(const std::string_view k) const  { return safe(impl).has(k); }
LLSD LLSD::get(const std::string_view k) const  { return safe(impl).get(k); }
LLSD LLSD::getKeys() const              { return safe(impl).getKeys(); }
void LLSD::insert(std::string_view k, const LLSD& v) { makeMap(impl).insert(k, v); }

LLSD& LLSD::with(std::string_view k, const LLSD& v)
                                        {
                                            makeMap(impl).insert(k, v);
                                            return *this;
                                        }
void LLSD::erase(const String& k)       { makeMap(impl).erase(k); }

LLSD& LLSD::operator[](const std::string_view k)
{
    LL_PROFILE_ZONE_SCOPED_CATEGORY_LLSD;
    return makeMap(impl).ref(k);
}
const LLSD& LLSD::operator[](const std::string_view k) const
{
    LL_PROFILE_ZONE_SCOPED_CATEGORY_LLSD;
    return safe(impl).ref(k);
}

LLSD LLSD::emptyArray()
{
    LLSD v;
    makeArray(v.impl);
    return v;
}

size_t LLSD::size() const               { return safe(impl).size(); }

LLSD LLSD::get(Integer i) const         { return safe(impl).get(i); }
void LLSD::set(Integer i, const LLSD& v){ makeArray(impl).set(i, v); }
void LLSD::insert(Integer i, const LLSD& v) { makeArray(impl).insert(i, v); }

LLSD& LLSD::with(Integer i, const LLSD& v)
                                        {
                                            makeArray(impl).insert(i, v);
                                            return *this;
                                        }
LLSD& LLSD::append(const LLSD& v)       { return makeArray(impl).append(v); }
void LLSD::erase(Integer i)             { makeArray(impl).erase(i); }

LLSD& LLSD::operator[](size_t i)
{
    LL_PROFILE_ZONE_SCOPED_CATEGORY_LLSD;
    return makeArray(impl).ref(i);
}
const LLSD& LLSD::operator[](size_t i) const
{
    LL_PROFILE_ZONE_SCOPED_CATEGORY_LLSD;
    return safe(impl).ref(i);
}

static const char *llsd_dump(const LLSD &llsd, bool useXMLFormat)
{
    // sStorage is used to hold the string representation of the llsd last
    // passed into this function.  If this function is never called (the
    // normal case when not debugging), nothing is allocated.  Otherwise
    // sStorage will point to the result of the last call.  This will actually
    // be one leak, but since this is used only when running under the
    // debugger, it should not be an issue.
    static char *sStorage = NULL;
    delete[] sStorage;
    std::string out_string;
    {
        std::ostringstream out;
        if (useXMLFormat)
            out << LLSDXMLStreamer(llsd);
        else
            out << LLSDNotationStreamer(llsd);
        out_string = out.str();
    }
    auto len = out_string.length();
    sStorage = new char[len + 1];
    memcpy(sStorage, out_string.c_str(), len);
    sStorage[len] = '\0';
    return sStorage;
}

/// Returns XML version of llsd -- only to be called from debugger
const char *LLSD::dumpXML(const LLSD &llsd)
{
    return llsd_dump(llsd, true);
}

/// Returns Notation version of llsd -- only to be called from debugger
const char *LLSD::dump(const LLSD &llsd)
{
    return llsd_dump(llsd, false);
}

LLSD::map_iterator          LLSD::beginMap()        { return makeMap(impl).beginMap(); }
LLSD::map_iterator          LLSD::endMap()          { return makeMap(impl).endMap(); }
LLSD::map_const_iterator    LLSD::beginMap() const  { return safe(impl).beginMap(); }
LLSD::map_const_iterator    LLSD::endMap() const    { return safe(impl).endMap(); }

LLSD::array_iterator        LLSD::beginArray()      { return makeArray(impl).beginArray(); }
LLSD::array_iterator        LLSD::endArray()        { return makeArray(impl).endArray(); }
LLSD::array_const_iterator  LLSD::beginArray() const{ return safe(impl).beginArray(); }
LLSD::array_const_iterator  LLSD::endArray() const  { return safe(impl).endArray(); }

LLSD::reverse_array_iterator    LLSD::rbeginArray()     { return makeArray(impl).rbeginArray(); }
LLSD::reverse_array_iterator    LLSD::rendArray()       { return makeArray(impl).rendArray(); }

namespace llsd
{

U32 allocationCount()                               { return LLSD::Impl::sAllocationCount; }
U32 outstandingCount()                              { return LLSD::Impl::sOutstandingCount; }

// Diagnostic dump of contents in an LLSD object
void dumpStats(const LLSD& llsd)                    { LLSD::Impl::getImpl(llsd).dumpStats(); }

} // namespace llsd

// static
std::string     LLSD::typeString(Type type)
{
    static const char * sTypeNameArray[] = {
        "Undefined",
        "Boolean",
        "Integer",
        "Real",
        "String",
        "UUID",
        "Date",
        "URI",
        "Binary",
        "Map",
        "Array"
    };

    if (0 <= type && type < LL_ARRAY_SIZE(sTypeNameArray))
    {
        return sTypeNameArray[type];
    }
    return STRINGIZE("** invalid type value " << type);
}