channels.cpp

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// channels.cpp - written and placed in the public domain by Wei Dai

#include "pch.h"

#ifndef CRYPTOPP_IMPORTS

#include "cryptlib.h"
#include "channels.h"

NAMESPACE_BEGIN(CryptoPP)
USING_NAMESPACE(std)

#if 0
void MessageSwitch::AddDefaultRoute(BufferedTransformation &destination, const std::string &channel)
{
        m_defaultRoutes.push_back(Route(&destination, channel));
}

void MessageSwitch::AddRoute(unsigned int begin, unsigned int end, BufferedTransformation &destination, const std::string &channel)
{
        RangeRoute route(begin, end, Route(&destination, channel));
        RouteList::iterator it = upper_bound(m_routes.begin(), m_routes.end(), route);
        m_routes.insert(it, route);
}

/*
class MessageRouteIterator
{
public:
        typedef MessageSwitch::RouteList::const_iterator RouteIterator;
        typedef MessageSwitch::DefaultRouteList::const_iterator DefaultIterator;

        bool m_useDefault;
        RouteIterator m_itRouteCurrent, m_itRouteEnd;
        DefaultIterator m_itDefaultCurrent, m_itDefaultEnd;

        MessageRouteIterator(MessageSwitch &ms, const std::string &channel)
                : m_channel(channel)
        {
                pair<MapIterator, MapIterator> range = cs.m_routeMap.equal_range(channel);
                if (range.first == range.second)
                {
                        m_useDefault = true;
                        m_itListCurrent = cs.m_defaultRoutes.begin();
                        m_itListEnd = cs.m_defaultRoutes.end();
                }
                else
                {
                        m_useDefault = false;
                        m_itMapCurrent = range.first;
                        m_itMapEnd = range.second;
                }
        }

        bool End() const
        {
                return m_useDefault ? m_itListCurrent == m_itListEnd : m_itMapCurrent == m_itMapEnd;
        }

        void Next()
        {
                if (m_useDefault)
                        ++m_itListCurrent;
                else
                        ++m_itMapCurrent;
        }

        BufferedTransformation & Destination()
        {
                return m_useDefault ? *m_itListCurrent->first : *m_itMapCurrent->second.first;
        }

        const std::string & Message()
        {
                if (m_useDefault)
                        return m_itListCurrent->second.get() ? *m_itListCurrent->second.get() : m_channel;
                else
                        return m_itMapCurrent->second.second;
        }
};

void MessageSwitch::Put(byte inByte);
void MessageSwitch::Put(const byte *inString, unsigned int length);

void MessageSwitch::Flush(bool completeFlush, int propagation=-1);
void MessageSwitch::MessageEnd(int propagation=-1);
void MessageSwitch::PutMessageEnd(const byte *inString, unsigned int length, int propagation=-1);
void MessageSwitch::MessageSeriesEnd(int propagation=-1);
*/
#endif


//
// ChannelRouteIterator

void ChannelRouteIterator::Reset(const std::string &channel)
{
        m_channel = channel;
        pair<MapIterator, MapIterator> range = m_cs.m_routeMap.equal_range(channel);
        if (range.first == range.second)
        {
                m_useDefault = true;
                m_itListCurrent = m_cs.m_defaultRoutes.begin();
                m_itListEnd = m_cs.m_defaultRoutes.end();
        }
        else
        {
                m_useDefault = false;
                m_itMapCurrent = range.first;
                m_itMapEnd = range.second;
        }
}

bool ChannelRouteIterator::End() const
{
        return m_useDefault ? m_itListCurrent == m_itListEnd : m_itMapCurrent == m_itMapEnd;
}

void ChannelRouteIterator::Next()
{
        if (m_useDefault)
                ++m_itListCurrent;
        else
                ++m_itMapCurrent;
}

BufferedTransformation & ChannelRouteIterator::Destination()
{
        return m_useDefault ? *m_itListCurrent->first : *m_itMapCurrent->second.first;
}

const std::string & ChannelRouteIterator::Channel()
{
        if (m_useDefault)
                return m_itListCurrent->second.get() ? *m_itListCurrent->second.get() : m_channel;
        else
                return m_itMapCurrent->second.second;
}


//
// ChannelSwitch

size_t ChannelSwitch::ChannelPut2(const std::string &channel, const byte *begin, size_t length, int messageEnd, bool blocking)
{
        if (m_blocked)
        {
                m_blocked = false;
                goto WasBlocked;
        }

        m_it.Reset(channel);

        while (!m_it.End())
        {
WasBlocked:
                if (m_it.Destination().ChannelPut2(m_it.Channel(), begin, length, messageEnd, blocking))
                {
                        m_blocked = true;
                        return 1;
                }

                m_it.Next();
        }

        return 0;
}

void ChannelSwitch::IsolatedInitialize(const NameValuePairs& parameters)
{
        CRYPTOPP_UNUSED(parameters);
        m_routeMap.clear();
        m_defaultRoutes.clear();
        m_blocked = false;
}

bool ChannelSwitch::ChannelFlush(const std::string &channel, bool completeFlush, int propagation, bool blocking)
{
        if (m_blocked)
        {
                m_blocked = false;
                goto WasBlocked;
        }

        m_it.Reset(channel);

        while (!m_it.End())
        {
          WasBlocked:
                if (m_it.Destination().ChannelFlush(m_it.Channel(), completeFlush, propagation, blocking))
                {
                        m_blocked = true;
                        return true;
                }

                m_it.Next();
        }

        return false;
}

bool ChannelSwitch::ChannelMessageSeriesEnd(const std::string &channel, int propagation, bool blocking)
{
        CRYPTOPP_UNUSED(blocking);
        if (m_blocked)
        {
                m_blocked = false;
                goto WasBlocked;
        }

        m_it.Reset(channel);

        while (!m_it.End())
        {
          WasBlocked:
                if (m_it.Destination().ChannelMessageSeriesEnd(m_it.Channel(), propagation))
                {
                        m_blocked = true;
                        return true;
                }

                m_it.Next();
        }

        return false;
}

byte * ChannelSwitch::ChannelCreatePutSpace(const std::string &channel, size_t &size)
{
        m_it.Reset(channel);
        if (!m_it.End())
        {
                BufferedTransformation &target = m_it.Destination();
                const std::string &ch = m_it.Channel();
                m_it.Next();
                if (m_it.End()) // there is only one target channel
                        return target.ChannelCreatePutSpace(ch, size);
        }
        size = 0;
        return NULL;
}

size_t ChannelSwitch::ChannelPutModifiable2(const std::string &channel, byte *inString, size_t length, int messageEnd, bool blocking)
{
        ChannelRouteIterator it(*this);
        it.Reset(channel);

        if (!it.End())
        {
                BufferedTransformation &target = it.Destination();
                const std::string &targetChannel = it.Channel();
                it.Next();
                if (it.End())   // there is only one target channel
                        return target.ChannelPutModifiable2(targetChannel, inString, length, messageEnd, blocking);
        }

        return ChannelPut2(channel, inString, length, messageEnd, blocking);
}

void ChannelSwitch::AddDefaultRoute(BufferedTransformation &destination)
{
        m_defaultRoutes.push_back(DefaultRoute(&destination, value_ptr<std::string>(NULL)));
}

void ChannelSwitch::RemoveDefaultRoute(BufferedTransformation &destination)
{
        for (DefaultRouteList::iterator it = m_defaultRoutes.begin(); it != m_defaultRoutes.end(); ++it)
                if (it->first == &destination && !it->second.get())
                {
                        m_defaultRoutes.erase(it);
                        break;
                }
}

void ChannelSwitch::AddDefaultRoute(BufferedTransformation &destination, const std::string &outChannel)
{
        m_defaultRoutes.push_back(DefaultRoute(&destination, outChannel));
}

void ChannelSwitch::RemoveDefaultRoute(BufferedTransformation &destination, const std::string &outChannel)
{
        for (DefaultRouteList::iterator it = m_defaultRoutes.begin(); it != m_defaultRoutes.end(); ++it)
                if (it->first == &destination && (it->second.get() && *it->second == outChannel))
                {
                        m_defaultRoutes.erase(it);
                        break;
                }
}

void ChannelSwitch::AddRoute(const std::string &inChannel, BufferedTransformation &destination, const std::string &outChannel)
{
        m_routeMap.insert(RouteMap::value_type(inChannel, Route(&destination, outChannel)));
}

void ChannelSwitch::RemoveRoute(const std::string &inChannel, BufferedTransformation &destination, const std::string &outChannel)
{
        typedef ChannelSwitch::RouteMap::iterator MapIterator;
        pair<MapIterator, MapIterator> range = m_routeMap.equal_range(inChannel);

        for (MapIterator it = range.first; it != range.second; ++it)
                if (it->second.first == &destination && it->second.second == outChannel)
                {
                        m_routeMap.erase(it);
                        break;
                }
}

NAMESPACE_END

#endif