rippled/modules/beast_core/text/StringPool.cpp

//------------------------------------------------------------------------------
/*
    This file is part of Beast: https://github.com/vinniefalco/Beast
    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>

    Portions of this file are from JUCE.
    Copyright (c) 2013 - Raw Material Software Ltd.
    Please visit http://www.juce.com

    Permission to use, copy, modify, and/or distribute this software for any
    purpose  with  or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.

    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================

StringPool::StringPool() noexcept   {}
StringPool::~StringPool()           {}

namespace StringPoolHelpers
{
    template <class StringType>
    String::CharPointerType getPooledStringFromArray (Array<String>& strings,
                                                      StringType newString,
                                                      const CriticalSection& lock)
    {
        const ScopedLock sl (lock);
        int start = 0;
        int end = strings.size();

        for (;;)
        {
            if (start >= end)
            {
                bassert (start <= end);
                strings.insert (start, newString);
                return strings.getReference (start).getCharPointer();
            }
            else
            {
                const String& startString = strings.getReference (start);

                if (startString == newString)
                    return startString.getCharPointer();

                const int halfway = (start + end) >> 1;

                if (halfway == start)
                {
                    if (startString.compare (newString) < 0)
                        ++start;

                    strings.insert (start, newString);
                    return strings.getReference (start).getCharPointer();
                }

                const int comp = strings.getReference (halfway).compare (newString);

                if (comp == 0)
                    return strings.getReference (halfway).getCharPointer();
                else if (comp < 0)
                    start = halfway;
                else
                    end = halfway;
            }
        }
    }
}

String::CharPointerType StringPool::getPooledString (const String& s)
{
    if (s.isEmpty())
        return String::empty.getCharPointer();

    return StringPoolHelpers::getPooledStringFromArray (strings, s, lock);
}

String::CharPointerType StringPool::getPooledString (const char* const s)
{
    if (s == nullptr || *s == 0)
        return String::empty.getCharPointer();

    return StringPoolHelpers::getPooledStringFromArray (strings, s, lock);
}

String::CharPointerType StringPool::getPooledString (const wchar_t* const s)
{
    if (s == nullptr || *s == 0)
        return String::empty.getCharPointer();

    return StringPoolHelpers::getPooledStringFromArray (strings, s, lock);
}

int StringPool::size() const noexcept
{
    return strings.size();
}

String::CharPointerType StringPool::operator[] (const int index) const noexcept
{
    return strings [index].getCharPointer();
}