source: git/src-cryptopp/mqueue.h

#ifndef CRYPTOPP_MQUEUE_H
#define CRYPTOPP_MQUEUE_H

#include "cryptlib.h"
#include "queue.h"
#include "filters.h"
#include "misc.h"

#include <deque>

NAMESPACE_BEGIN(CryptoPP)

//! Message Queue
class CRYPTOPP_DLL MessageQueue : public AutoSignaling<BufferedTransformation>
{
public:
        MessageQueue(unsigned int nodeSize=256);

        void IsolatedInitialize(const NameValuePairs &parameters)
                {m_queue.IsolatedInitialize(parameters); m_lengths.assign(1, 0U); m_messageCounts.assign(1, 0U);}
        size_t Put2(const byte *begin, size_t length, int messageEnd, bool blocking)
        {
                CRYPTOPP_UNUSED(blocking);
                m_queue.Put(begin, length);
                m_lengths.back() += length;
                if (messageEnd)
                {
                        m_lengths.push_back(0);
                        m_messageCounts.back()++;
                }
                return 0;
        }
        bool IsolatedFlush(bool hardFlush, bool blocking)
                {CRYPTOPP_UNUSED(hardFlush), CRYPTOPP_UNUSED(blocking); return false;}
        bool IsolatedMessageSeriesEnd(bool blocking)
                {CRYPTOPP_UNUSED(blocking); m_messageCounts.push_back(0); return false;}

        lword MaxRetrievable() const
                {return m_lengths.front();}
        bool AnyRetrievable() const
                {return m_lengths.front() > 0;}

        size_t TransferTo2(BufferedTransformation &target, lword &transferBytes, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true);
        size_t CopyRangeTo2(BufferedTransformation &target, lword &begin, lword end=LWORD_MAX, const std::string &channel=DEFAULT_CHANNEL, bool blocking=true) const;

        lword TotalBytesRetrievable() const
                {return m_queue.MaxRetrievable();}
        unsigned int NumberOfMessages() const
                {return (unsigned int)m_lengths.size()-1;}
        bool GetNextMessage();

        unsigned int NumberOfMessagesInThisSeries() const
                {return m_messageCounts[0];}
        unsigned int NumberOfMessageSeries() const
                {return (unsigned int)m_messageCounts.size()-1;}

        unsigned int CopyMessagesTo(BufferedTransformation &target, unsigned int count=UINT_MAX, const std::string &channel=DEFAULT_CHANNEL) const;

        const byte * Spy(size_t &contiguousSize) const;

        void swap(MessageQueue &rhs);

private:
        ByteQueue m_queue;
        std::deque<lword> m_lengths;
        std::deque<unsigned int> m_messageCounts;
};


//! A filter that checks messages on two channels for equality
class CRYPTOPP_DLL EqualityComparisonFilter : public Unflushable<Multichannel<Filter> >
{
public:
        struct MismatchDetected : public Exception {MismatchDetected() : Exception(DATA_INTEGRITY_CHECK_FAILED, "EqualityComparisonFilter: did not receive the same data on two channels") {}};

        /*! if throwIfNotEqual is false, this filter will output a '\\0' byte when it detects a mismatch, '\\1' otherwise */
        EqualityComparisonFilter(BufferedTransformation *attachment=NULL, bool throwIfNotEqual=true, const std::string &firstChannel="0", const std::string &secondChannel="1")
                : m_throwIfNotEqual(throwIfNotEqual), m_mismatchDetected(false)
                , m_firstChannel(firstChannel), m_secondChannel(secondChannel)
                {Detach(attachment);}

        size_t ChannelPut2(const std::string &channel, const byte *begin, size_t length, int messageEnd, bool blocking);
        bool ChannelMessageSeriesEnd(const std::string &channel, int propagation=-1, bool blocking=true);

private:
        unsigned int MapChannel(const std::string &channel) const;
        bool HandleMismatchDetected(bool blocking);

        bool m_throwIfNotEqual, m_mismatchDetected;
        std::string m_firstChannel, m_secondChannel;
        MessageQueue m_q[2];
};

NAMESPACE_END

#ifndef __BORLANDC__
NAMESPACE_BEGIN(std)
template<> inline void swap(CryptoPP::MessageQueue &a, CryptoPP::MessageQueue &b)
{
        a.swap(b);
}
NAMESPACE_END
#endif

#endif