path: root/src/HTTP/NameValueParser.cpp

// NameValueParser.cpp

// Implements the cNameValueParser class that parses strings in the "name=value;name2=value2" format into a stringmap

#include "Globals.h"
#include "NameValueParser.h"





// DEBUG: Self-test

#if 0

class cNameValueParserTest
{
public:
	cNameValueParserTest(void)
	{
		const char Data[] = "   Name1=Value1;Name2 = Value 2; Name3 =\"Value 3\"; Name4 =\'Value 4\'; Name5=\"Confusing; isn\'t it?\"";

		// Now try parsing char-by-char, to debug transitions across datachunk boundaries:
		cNameValueParser Parser2;
		for (size_t i = 0; i < sizeof(Data) - 1; i++)
		{
			Parser2.Parse(Data + i, 1);
		}
		Parser2.Finish();

		// Parse as a single chunk of data:
		cNameValueParser Parser(Data, sizeof(Data) - 1);

		// Use the debugger to inspect the Parser variable

		// Check that the two parsers have the same content:
		for (cNameValueParser::const_iterator itr = Parser.begin(), end = Parser.end(); itr != end; ++itr)
		{
			ASSERT(Parser2[itr->first] == itr->second);
		}  // for itr - Parser[]

		// Try parsing in 2-char chunks:
		cNameValueParser Parser3;
		for (int i = 0; i < sizeof(Data) - 2; i += 2)
		{
			Parser3.Parse(Data + i, 2);
		}
		if ((sizeof(Data) % 2) == 0)  // There are even number of chars, including the NUL, so the data has an odd length. Parse one more char
		{
			Parser3.Parse(Data + sizeof(Data) - 2, 1);
		}
		Parser3.Finish();

		// Check that the third parser has the same content:
		for (cNameValueParser::const_iterator itr = Parser.begin(), end = Parser.end(); itr != end; ++itr)
		{
			ASSERT(Parser3[itr->first] == itr->second);
		}  // for itr - Parser[]

		printf("cNameValueParserTest done");
	}
} g_Test;

#endif





////////////////////////////////////////////////////////////////////////////////
// cNameValueParser:

cNameValueParser::cNameValueParser(bool a_AllowsKeyOnly) :
	m_State(psKeySpace), m_AllowsKeyOnly(a_AllowsKeyOnly)
{
}





cNameValueParser::cNameValueParser(const char * a_Data, size_t a_Size, bool a_AllowsKeyOnly) :
	m_State(psKeySpace), m_AllowsKeyOnly(a_AllowsKeyOnly)
{
	Parse(a_Data, a_Size);
}





void cNameValueParser::Parse(const char * a_Data, size_t a_Size)
{
	ASSERT(m_State != psFinished);  // Calling Parse() after Finish() is wrong!

	size_t Last = 0;
	for (size_t i = 0; i < a_Size;)
	{
		switch (m_State)
		{
			case psInvalid:
			case psFinished:
			{
				return;
			}

			case psKeySpace:
			{
				// Skip whitespace until a non-whitespace is found, then start the key:
				while ((i < a_Size) && (a_Data[i] <= ' '))
				{
					i++;
				}
				if ((i < a_Size) && (a_Data[i] > ' '))
				{
					m_State = psKey;
					Last = i;
				}
				break;
			}

			case psKey:
			{
				// Read the key until whitespace or an equal sign:
				while (i < a_Size)
				{
					if (a_Data[i] == '=')
					{
						m_CurrentKey.append(a_Data + Last, i - Last);
						i++;
						Last = i;
						m_State = psEqual;
						break;
					}
					else if (a_Data[i] <= ' ')
					{
						m_CurrentKey.append(a_Data + Last, i - Last);
						i++;
						Last = i;
						m_State = psEqualSpace;
						break;
					}
					else if (a_Data[i] == ';')
					{
						if (!m_AllowsKeyOnly)
						{
							m_State = psInvalid;
							return;
						}
						m_CurrentKey.append(a_Data + Last, i - Last);
						i++;
						Last = i;
						(*this)[m_CurrentKey] = "";
						m_CurrentKey.clear();
						m_State = psKeySpace;
						break;
					}
					else if ((a_Data[i] == '\"') || (a_Data[i] == '\''))
					{
						m_State = psInvalid;
						return;
					}
					i++;
				}  // while (i < a_Size)
				if (i == a_Size)
				{
					// Still the key, ran out of data to parse, store the part of the key parsed so far:
					m_CurrentKey.append(a_Data + Last, a_Size - Last);
					return;
				}
				break;
			}

			case psEqualSpace:
			{
				// The space before the expected equal sign; the current key is already assigned
				while (i < a_Size)
				{
					if (a_Data[i] == '=')
					{
						m_State = psEqual;
						i++;
						Last = i;
						break;
					}
					else if (a_Data[i] == ';')
					{
						// Key-only
						if (!m_AllowsKeyOnly)
						{
							m_State = psInvalid;
							return;
						}
						i++;
						Last = i;
						(*this)[m_CurrentKey] = "";
						m_CurrentKey.clear();
						m_State = psKeySpace;
						break;
					}
					else if (a_Data[i] > ' ')
					{
						m_State = psInvalid;
						return;
					}
					i++;
				}  // while (i < a_Size)
				break;
			}  // case psEqualSpace

			case psEqual:
			{
				// just parsed the equal-sign
				while (i < a_Size)
				{
					if (a_Data[i] == ';')
					{
						if (!m_AllowsKeyOnly)
						{
							m_State = psInvalid;
							return;
						}
						i++;
						Last = i;
						(*this)[m_CurrentKey] = "";
						m_CurrentKey.clear();
						m_State = psKeySpace;
						break;
					}
					else if (a_Data[i] == '\"')
					{
						i++;
						Last = i;
						m_State = psValueInDQuotes;
						break;
					}
					else if (a_Data[i] == '\'')
					{
						i++;
						Last = i;
						m_State = psValueInSQuotes;
						break;
					}
					else
					{
						m_CurrentValue.push_back(a_Data[i]);
						i++;
						Last = i;
						m_State = psValueRaw;
						break;
					}
				}  // while (i < a_Size)
				break;
			}  // case psEqual

			case psValueInDQuotes:
			{
				while (i < a_Size)
				{
					if (a_Data[i] == '\"')
					{
						m_CurrentValue.append(a_Data + Last, i - Last);
						(*this)[m_CurrentKey] = m_CurrentValue;
						m_CurrentKey.clear();
						m_CurrentValue.clear();
						m_State = psAfterValue;
						i++;
						Last = i;
						break;
					}
					i++;
				}  // while (i < a_Size)
				if (i == a_Size)
				{
					m_CurrentValue.append(a_Data + Last, a_Size - Last);
				}
				break;
			}  // case psValueInDQuotes

			case psValueInSQuotes:
			{
				while (i < a_Size)
				{
					if (a_Data[i] == '\'')
					{
						m_CurrentValue.append(a_Data + Last, i - Last);
						(*this)[m_CurrentKey] = m_CurrentValue;
						m_CurrentKey.clear();
						m_CurrentValue.clear();
						m_State = psAfterValue;
						i++;
						Last = i;
						break;
					}
					i++;
				}  // while (i < a_Size)
				if (i == a_Size)
				{
					m_CurrentValue.append(a_Data + Last, a_Size - Last);
				}
				break;
			}  // case psValueInSQuotes

			case psValueRaw:
			{
				while (i < a_Size)
				{
					if (a_Data[i] == ';')
					{
						m_CurrentValue.append(a_Data + Last, i - Last);
						(*this)[m_CurrentKey] = m_CurrentValue;
						m_CurrentKey.clear();
						m_CurrentValue.clear();
						m_State = psKeySpace;
						i++;
						Last = i;
						break;
					}
					i++;
				}
				if (i == a_Size)
				{
					m_CurrentValue.append(a_Data + Last, a_Size - Last);
				}
				break;
			}  // case psValueRaw

			case psAfterValue:
			{
				// Between the closing DQuote or SQuote and the terminating semicolon
				while (i < a_Size)
				{
					if (a_Data[i] == ';')
					{
						m_State = psKeySpace;
						i++;
						Last = i;
						break;
					}
					else if (a_Data[i] < ' ')
					{
						i++;
						continue;
					}
					m_State = psInvalid;
					return;
				}  // while (i < a_Size)
				break;
			}
		}  // switch (m_State)
	}  // for i - a_Data[]
}





bool cNameValueParser::Finish(void)
{
	switch (m_State)
	{
		case psInvalid:
		{
			return false;
		}
		case psFinished:
		{
			return true;
		}
		case psKey:
		case psEqualSpace:
		case psEqual:
		{
			if ((m_AllowsKeyOnly) && !m_CurrentKey.empty())
			{
				(*this)[m_CurrentKey] = "";
				m_State = psFinished;
				return true;
			}
			m_State = psInvalid;
			return false;
		}
		case psValueRaw:
		{
			(*this)[m_CurrentKey] = m_CurrentValue;
			m_State = psFinished;
			return true;
		}
		case psValueInDQuotes:
		case psValueInSQuotes:
		{
			// Missing the terminating quotes, this is an error
			m_State = psInvalid;
			return false;
		}
		case psKeySpace:
		case psAfterValue:
		{
			m_State = psFinished;
			return true;
		}
	}
	UNREACHABLE("Unsupported name value parser state");
}