bool CJsonOverUTTPReader::ReadMessage(CUTTPReader& reader)
{
for (;;)
switch (reader.GetNextEvent()) {
case CUTTPReader::eChunkPart:
switch (m_State) {
case eExpectNextToken:
m_State = eReadingString;
m_CurrentChunk.assign(reader.GetChunkPart(),
reader.GetChunkPartSize());
break;
case eReadingString:
m_CurrentChunk.append(reader.GetChunkPart(),
reader.GetChunkPartSize());
break;
case eReadingDouble:
// The underlying transport protocol guarantees
// that m_Double boundaries will not be exceeded.
memcpy(m_DoublePtr, reader.GetChunkPart(),
reader.GetChunkPartSize());
m_DoublePtr += reader.GetChunkPartSize();
break;
default: /* case eMessageComplete: */
goto ThrowUnexpectedTrailingToken;
}
break;
case CUTTPReader::eChunk:
switch (m_State) {
case eExpectNextToken:
m_CurrentChunk.assign(reader.GetChunkPart(),
reader.GetChunkPartSize());
break;
case eReadingString:
m_State = eExpectNextToken;
m_CurrentChunk.append(reader.GetChunkPart(),
reader.GetChunkPartSize());
break;
case eReadingDouble:
m_State = eExpectNextToken;
memcpy(m_DoublePtr, reader.GetChunkPart(),
reader.GetChunkPartSize());
if (m_DoubleEndianness != DOUBLE_PREFIX)
reverse(reinterpret_cast<char*>(&m_Double),
reinterpret_cast<char*>(&m_Double + 1));
if (!x_AddNewNode(CJsonNode::NewDoubleNode(m_Double)))
m_State = eMessageComplete;
continue;
default: /* case eMessageComplete: */
goto ThrowUnexpectedTrailingToken;
}
if (!m_CurrentNode) {
m_CurrentNode = CJsonNode::NewStringNode(m_CurrentChunk);
m_State = eMessageComplete;
} else if (m_HashValueIsExpected) {
m_HashValueIsExpected = false;
m_CurrentNode.SetString(m_HashKey, m_CurrentChunk);
} else
// The current node is either a JSON object or an array,
// because if it was a non-container node, m_State would
// be eMessageComplete.
if (m_CurrentNode.IsArray())
m_CurrentNode.AppendString(m_CurrentChunk);
else {
m_HashKey = m_CurrentChunk;
m_HashValueIsExpected = true;
}
break;
case CUTTPReader::eControlSymbol:
{
char control_symbol = reader.GetControlSymbol();
if (control_symbol == '\n') {
if (m_State != eMessageComplete) {
NCBI_THROW(CJsonOverUTTPException, eUnexpectedEOM,
"JSON-over-UTTP: Unexpected end of message");
}
return true;
}
if (m_State != eExpectNextToken)
goto ThrowChunkContinuationExpected;
switch (control_symbol) {
case '[':
case '{':
{
CJsonNode new_node(control_symbol == '[' ?
CJsonNode::NewArrayNode() :
CJsonNode::NewObjectNode());
if (x_AddNewNode(new_node)) {
m_NodeStack.push_back(m_CurrentNode);
m_CurrentNode = new_node;
}
}
break;
case ']':
case '}':
if (!m_CurrentNode ||
(control_symbol == ']') ^ m_CurrentNode.IsArray()) {
NCBI_THROW(CJsonOverUTTPException, eUnexpectedClosingBracket,
"JSON-over-UTTP: Unexpected closing bracket");
}
if (m_NodeStack.empty())
m_State = eMessageComplete;
else {
m_CurrentNode = m_NodeStack.back();
m_NodeStack.pop_back();
}
break;
case 'D':
case 'd':
switch (reader.ReadRawData(sizeof(double))) {
default: /* case CUTTPReader::eEndOfBuffer: */
m_State = eReadingDouble;
m_DoubleEndianness = control_symbol;
m_DoublePtr = reinterpret_cast<char*>(&m_Double);
return false;
case CUTTPReader::eChunkPart:
m_State = eReadingDouble;
m_DoubleEndianness = control_symbol;
memcpy(&m_Double, reader.GetChunkPart(),
reader.GetChunkPartSize());
m_DoublePtr = reinterpret_cast<char*>(&m_Double) +
reader.GetChunkPartSize();
break;
case CUTTPReader::eChunk:
_ASSERT(reader.GetChunkPartSize() == sizeof(double));
if (control_symbol == DOUBLE_PREFIX)
memcpy(&m_Double, reader.GetChunkPart(),
sizeof(double));
else {
// Copy the entire chunk to
// m_Double in reverse order.
const char* src = reader.GetChunkPart();
char* dst = reinterpret_cast<char*>(&m_Double + 1);
int count = sizeof(double);
do
*--dst = *src++;
while (--count > 0);
}
if (!x_AddNewNode(CJsonNode::NewDoubleNode(m_Double)))
m_State = eMessageComplete;
}
break;
case 'Y':
if (!x_AddNewNode(CJsonNode::NewBooleanNode(true)))
m_State = eMessageComplete;
break;
case 'N':
if (!x_AddNewNode(CJsonNode::NewBooleanNode(false)))
m_State = eMessageComplete;
break;
case 'U':
if (!x_AddNewNode(CJsonNode::NewNullNode()))
m_State = eMessageComplete;
break;
default:
NCBI_THROW_FMT(CJsonOverUTTPException,
eUnknownControlSymbol,
"JSON-over-UTTP: Unknown control symbol '" <<
NStr::PrintableString(CTempString(&control_symbol,
1)) << '\'');
}
}
break;
case CUTTPReader::eNumber:
switch (m_State) {
case eExpectNextToken:
if (!x_AddNewNode(CJsonNode::NewIntegerNode(reader.GetNumber())))
m_State = eMessageComplete;
break;
case eMessageComplete:
goto ThrowUnexpectedTrailingToken;
default:
goto ThrowChunkContinuationExpected;
}
break;
case CUTTPReader::eEndOfBuffer:
return false;
default: /* case CUTTPReader::eFormatError: */
NCBI_THROW(CJsonOverUTTPException, eUTTPFormatError,
"JSON-over-UTTP: UTTP format error");
}
ThrowUnexpectedTrailingToken:
NCBI_THROW(CJsonOverUTTPException, eUnexpectedTrailingToken,
"JSON-over-UTTP: Received a token while expected EOM");
ThrowChunkContinuationExpected:
NCBI_THROW(CJsonOverUTTPException, eChunkContinuationExpected,
"JSON-over-UTTP: Chunk continuation expected");
}
CJsonOverUTTPReader::EParsingEvent
CJsonOverUTTPReader::ProcessParsingEvents(CUTTPReader& reader)
{
for (;;)
switch (reader.GetNextEvent()) {
case CUTTPReader::eChunkPart:
if (m_ReadingChunk)
m_CurrentChunk.append(reader.GetChunkPart(),
reader.GetChunkPartSize());
else {
m_ReadingChunk = true;
m_CurrentChunk.assign(reader.GetChunkPart(),
reader.GetChunkPartSize());
}
break;
case CUTTPReader::eChunk:
if (m_ReadingChunk) {
m_ReadingChunk = false;
m_CurrentChunk.append(reader.GetChunkPart(),
reader.GetChunkPartSize());
} else
m_CurrentChunk.assign(reader.GetChunkPart(),
reader.GetChunkPartSize());
if (m_CurrentNode.IsArray())
m_CurrentNode.PushString(m_CurrentChunk);
else // The current node is eObject.
if (m_HashValueIsExpected) {
m_HashValueIsExpected = false;
m_CurrentNode.SetString(m_HashKey, m_CurrentChunk);
} else {
m_HashValueIsExpected = true;
m_HashKey = m_CurrentChunk;
}
break;
case CUTTPReader::eControlSymbol:
{
if (m_ReadingChunk)
return eChunkContinuationExpected;
char control_symbol = reader.GetControlSymbol();
switch (control_symbol) {
case '\n':
if (m_NodeStack.size() != 0)
return eUnexpectedEOM;
if (reader.GetNextEvent() != CUTTPReader::eEndOfBuffer)
return eExtraCharsPastEOM;
return eEndOfMessage;
case '[':
case '{':
{
CJsonNode new_node(control_symbol == '[' ?
CJsonNode::NewArrayNode() :
CJsonNode::NewObjectNode());
if (m_CurrentNode.IsArray())
m_CurrentNode.PushNode(new_node);
else // The current node is eObject.
if (m_HashValueIsExpected) {
m_HashValueIsExpected = false;
m_CurrentNode.SetNode(m_HashKey, new_node);
} else
return eHashKeyMustBeString;
m_NodeStack.push_back(m_CurrentNode);
m_CurrentNode = new_node;
}
break;
case ']':
case '}':
if (m_NodeStack.size() == 0 || (control_symbol == ']') ^
m_CurrentNode.IsArray())
return eUnexpectedClosingBracket;
m_CurrentNode = m_NodeStack.back();
m_NodeStack.pop_back();
break;
case 'Y':
case 'N':
{
bool boolean = control_symbol == 'Y';
if (m_CurrentNode.IsArray())
m_CurrentNode.PushBoolean(boolean);
else // The current node is eObject.
if (m_HashValueIsExpected) {
m_HashValueIsExpected = false;
m_CurrentNode.SetBoolean(m_HashKey, boolean);
} else
return eHashKeyMustBeString;
}
break;
case 'U':
if (m_CurrentNode.IsArray())
m_CurrentNode.PushNull();
else // The current node is eObject.
if (m_HashValueIsExpected) {
m_HashValueIsExpected = false;
m_CurrentNode.SetNull(m_HashKey);
} else
return eHashKeyMustBeString;
break;
default:
return eUnknownControlSymbol;
}
}
break;
case CUTTPReader::eNumber:
if (m_ReadingChunk)
return eChunkContinuationExpected;
if (m_CurrentNode.IsArray())
m_CurrentNode.PushNumber(reader.GetNumber());
else // The current node is eObject.
if (m_HashValueIsExpected) {
m_HashValueIsExpected = false;
m_CurrentNode.SetNumber(m_HashKey, reader.GetNumber());
} else
return eHashKeyMustBeString;
break;
case CUTTPReader::eEndOfBuffer:
return eNextBuffer;
default: // case CUTTPReader::eFormatError:
return eUTTPFormatError;
}
}
