1// mqueue.cpp - written and placed in the public domain by Wei Dai
2
3#include "pch.h"
4
5#ifndef CRYPTOPP_IMPORTS
6
7#include "mqueue.h"
8
9NAMESPACE_BEGIN(CryptoPP)
10
11MessageQueue::MessageQueue(unsigned int nodeSize)
12	: m_queue(nodeSize), m_lengths(1, 0U), m_messageCounts(1, 0U)
13{
14}
15
16size_t MessageQueue::CopyRangeTo2(BufferedTransformation &target, lword &begin, lword end, const std::string &channel, bool blocking) const
17{
18	if (begin >= MaxRetrievable())
19		return 0;
20
21	return m_queue.CopyRangeTo2(target, begin, STDMIN(MaxRetrievable(), end), channel, blocking);
22}
23
24size_t MessageQueue::TransferTo2(BufferedTransformation &target, lword &transferBytes, const std::string &channel, bool blocking)
25{
26	transferBytes = STDMIN(MaxRetrievable(), transferBytes);
27	size_t blockedBytes = m_queue.TransferTo2(target, transferBytes, channel, blocking);
28	m_lengths.front() -= transferBytes;
29	return blockedBytes;
30}
31
32bool MessageQueue::GetNextMessage()
33{
34	if (NumberOfMessages() > 0 && !AnyRetrievable())
35	{
36		m_lengths.pop_front();
37		if (m_messageCounts[0] == 0 && m_messageCounts.size() > 1)
38			m_messageCounts.pop_front();
39		return true;
40	}
41	else
42		return false;
43}
44
45unsigned int MessageQueue::CopyMessagesTo(BufferedTransformation &target, unsigned int count, const std::string &channel) const
46{
47	ByteQueue::Walker walker(m_queue);
48	std::deque<lword>::const_iterator it = m_lengths.begin();
49	unsigned int i;
50	for (i=0; i<count && it != --m_lengths.end(); ++i, ++it)
51	{
52		walker.TransferTo(target, *it, channel);
53		if (GetAutoSignalPropagation())
54			target.ChannelMessageEnd(channel, GetAutoSignalPropagation()-1);
55	}
56	return i;
57}
58
59void MessageQueue::swap(MessageQueue &rhs)
60{
61	m_queue.swap(rhs.m_queue);
62	m_lengths.swap(rhs.m_lengths);
63}
64
65const byte * MessageQueue::Spy(size_t &contiguousSize) const
66{
67	const byte *result = m_queue.Spy(contiguousSize);
68	contiguousSize = UnsignedMin(contiguousSize, MaxRetrievable());
69	return result;
70}
71
72// *************************************************************
73
74unsigned int EqualityComparisonFilter::MapChannel(const std::string &channel) const
75{
76	if (channel == m_firstChannel)
77		return 0;
78	else if (channel == m_secondChannel)
79		return 1;
80	else
81		return 2;
82}
83
84size_t EqualityComparisonFilter::ChannelPut2(const std::string &channel, const byte *inString, size_t length, int messageEnd, bool blocking)
85{
86	if (!blocking)
87		throw BlockingInputOnly("EqualityComparisonFilter");
88
89	unsigned int i = MapChannel(channel);
90
91	if (i == 2)
92		return Output(3, inString, length, messageEnd, blocking, channel);
93	else if (m_mismatchDetected)
94		return 0;
95	else
96	{
97		MessageQueue &q1 = m_q[i], &q2 = m_q[1-i];
98
99		if (q2.AnyMessages() && q2.MaxRetrievable() < length)
100			goto mismatch;
101
102		while (length > 0 && q2.AnyRetrievable())
103		{
104			size_t len = length;
105			const byte *data = q2.Spy(len);
106			len = STDMIN(len, length);
107			if (memcmp(inString, data, len) != 0)
108				goto mismatch;
109			inString += len;
110			length -= len;
111			q2.Skip(len);
112		}
113
114		q1.Put(inString, length);
115
116		if (messageEnd)
117		{
118			if (q2.AnyRetrievable())
119				goto mismatch;
120			else if (q2.AnyMessages())
121				q2.GetNextMessage();
122			else if (q2.NumberOfMessageSeries() > 0)
123				goto mismatch;
124			else
125				q1.MessageEnd();
126		}
127
128		return 0;
129
130mismatch:
131		return HandleMismatchDetected(blocking);
132	}
133}
134
135bool EqualityComparisonFilter::ChannelMessageSeriesEnd(const std::string &channel, int propagation, bool blocking)
136{
137	unsigned int i = MapChannel(channel);
138
139	if (i == 2)
140	{
141		OutputMessageSeriesEnd(4, propagation, blocking, channel);
142		return false;
143	}
144	else if (m_mismatchDetected)
145		return false;
146	else
147	{
148		MessageQueue &q1 = m_q[i], &q2 = m_q[1-i];
149
150		if (q2.AnyRetrievable() || q2.AnyMessages())
151			goto mismatch;
152		else if (q2.NumberOfMessageSeries() > 0)
153			return Output(2, (const byte *)"\1", 1, 0, blocking) != 0;
154		else
155			q1.MessageSeriesEnd();
156
157		return false;
158
159mismatch:
160		return HandleMismatchDetected(blocking);
161	}
162}
163
164bool EqualityComparisonFilter::HandleMismatchDetected(bool blocking)
165{
166	m_mismatchDetected = true;
167	if (m_throwIfNotEqual)
168		throw MismatchDetected();
169	return Output(1, (const byte *)"\0", 1, 0, blocking) != 0;
170}
171
172NAMESPACE_END
173
174#endif
175