dbms: development.

dbms/include/DB/Core/ErrorCodes.h

@@ -35,6 +35,9 @@ namespace ErrorCodes
 		CANNOT_WRITE_TO_OSTREAM,
 		CANNOT_PARSE_ESCAPE_SEQUENCE,
 		CANNOT_PARSE_QUOTED_STRING,
+		CANNOT_PARSE_INPUT_ASSERTION_FAILED,
+		CANNOT_PRINT_FLOAT_OR_DOUBLE_NUMBER,
+		CANNOT_PRINT_INTEGER,
 	};
 }
 

dbms/include/DB/Core/ReadBuffer.h

@@ -1,8 +1,7 @@
 #ifndef DBMS_COMMON_READBUFFER_H
 #define DBMS_COMMON_READBUFFER_H
 
-#include <string.h>		// memcpy
-
+#include <cstring>
 #include <algorithm>
 
 #include <DB/Core/Types.h>
@@ -57,45 +56,87 @@ public:
 	virtual ~ReadBuffer() {}
 
 
-	/// Функции для чтения конкретных данных
-
 	inline bool eof()
 	{
 		return pos == working_buffer.end() && !next();
 	}
 
-
-	void readChar(char & x)
-	{
-		x = 0;
-		if (!eof())
-		{
-			x = *pos;
-			++pos;
-		}
-	}
-
-
 	void ignore()
 	{
 		if (!eof())
 			++pos;
 	}
 
+	size_t read(char * to, size_t n)
+	{
+		size_t bytes_copied = 0;
+
+		while (!eof() && bytes_copied < n)
+		{
+			size_t bytes_to_copy = std::min(static_cast<size_t>(working_buffer.end() - pos), n - bytes_copied);
+			std::memcpy(to, pos, bytes_to_copy);
+			pos += bytes_to_copy;
+		}
+
+		return bytes_copied;
+	}
+
+protected:
+	char internal_buffer[DEFAULT_READ_BUFFER_SIZE];
+	Buffer working_buffer;
+	Position pos;
+};
+
+
+
+/// Функции-помошники для форматированного чтения
+
+static inline char parseEscapeSequence(char c)
+{
+	switch(c)
+	{
+		case 'b':
+			return '\b';
+		case 'f':
+			return '\f';
+		case 'n':
+			return '\n';
+		case 'r':
+			return '\r';
+		case 't':
+			return '\t';
+		case '0':
+			return '\0';
+		default:
+			return c;
+	}
+}
+
+static void assertString(const char * s, ReadBuffer & buf)
+{
+	for (; *s; ++s)
+	{
+		if (buf.eof() || *buf.position() != *s)
+			throw Exception(String("Cannot parse input: expected ") + s, ErrorCodes::CANNOT_PARSE_INPUT_ASSERTION_FAILED);
+		++buf.position();
+	}
+}
+
 
 /// грубо
 template <typename T>
-	void readIntText(T & x)
+void readIntText(T & x, ReadBuffer & buf)
 {
+	bool negative = false;
 	x = 0;
-		while (!eof())
+	while (!buf.eof())
 	{
-			switch (*pos)
+		switch (*buf.position())
 		{
 			case '+':
 				break;
 			case '-':
-					x = -x;
+				negative = true;
 				break;
 			case '0':
 			case '1':
@@ -108,31 +149,36 @@ public:
 			case '8':
 			case '9':
 				x *= 10;
-					x += *pos - '0';
+				x += *buf.position() - '0';
 				break;
 			default:
+				if (negative)
+					x = -x;
 				return;
 		}
-			++pos;
+		++buf.position();
 	}
+	if (negative)
+		x = -x;
 }
 
-	/// грубо; поддерживается только простой формат
+/// грубо
 template <typename T>
-	void readFloatText(T & x)
+void readFloatText(T & x, ReadBuffer & buf)
 {
+	bool negative = false;
 	x = 0;
 	bool after_point = false;
 	double power_of_ten = 1;
 
-		while (!eof())
+	while (!buf.eof())
 	{
-			switch (*pos)
+		switch (*buf.position())
 		{
 			case '+':
 				break;
 			case '-':
-					x = -x;
+				negative = true;
 				break;
 			case '.':
 				after_point = true;
@@ -150,99 +196,156 @@ public:
 				if (after_point)
 				{
 					power_of_ten /= 10;
-						x += (*pos - '0') * power_of_ten;
+					x += (*buf.position() - '0') * power_of_ten;
 				}
 				else
 				{
 					x *= 10;
-						x += *pos - '0';
+					x += *buf.position() - '0';
 				}
 				break;
-				default:
+			case 'e':
+			case 'E':
+			{
+				++buf.position();
+				Int32 exponent = 0;
+				readIntText(exponent, buf);
+				if (exponent == 0)
+				{
+					if (negative)
+						x = -x;
 					return;
 				}
-			++pos;
+				else if (exponent > 0)
+				{
+					for (Int32 i = 0; i < exponent; ++i)
+						x *= 10;
+					if (negative)
+						x = -x;
+					return;
 				}
+				else
+				{
+					for (Int32 i = 0; i < exponent; ++i)
+						x /= 10;
+					if (negative)
+						x = -x;
+					return;
+				}
+			}
+			case 'i':
+				++buf.position();
+				assertString("nf", buf);
+				x = std::numeric_limits<T>::infinity();
+				if (negative)
+					x = -x;
+				return;
+			case 'I':
+				++buf.position();
+				assertString("NF", buf);
+				x = std::numeric_limits<T>::infinity();
+				if (negative)
+					x = -x;
+				return;
+			case 'n':
+				++buf.position();
+				assertString("an", buf);
+				x = std::numeric_limits<T>::quiet_NaN();
+				return;
+			case 'N':
+				++buf.position();
+				assertString("AN", buf);
+				x = std::numeric_limits<T>::quiet_NaN();
+				return;
+			default:
+				if (negative)
+					x = -x;
+				return;
+		}
+		++buf.position();
+	}
+	if (negative)
+		x = -x;
 }
 
 /// грубо; всё до '\n' или '\t'
-	void readString(String & s)
+void readString(String & s, ReadBuffer & buf)
 {
 	s = "";
-		while (!eof())
+	while (!buf.eof())
 	{
 		size_t bytes = 0;
-			for (; pos + bytes != working_buffer.end(); ++bytes)
-				if (pos[bytes] == '\t' || pos[bytes] == '\n')
+		for (; buf.position() + bytes != buf.buffer().end(); ++bytes)
+			if (buf.position()[bytes] == '\t' || buf.position()[bytes] == '\n')
 				break;
 
-			s.append(pos, bytes);
-			pos += bytes;
+		s.append(buf.position(), bytes);
+		buf.position() += bytes;
 
-			if (pos != working_buffer.end())
+		if (buf.position() != buf.buffer().end())
 			return;
 	}
 }
 
-	void readEscapedString(String & s)
+void readEscapedString(String & s, ReadBuffer & buf)
 {
 	s = "";
-		while (!eof())
+	while (!buf.eof())
 	{
 		size_t bytes = 0;
-			for (; pos + bytes != working_buffer.end(); ++bytes)
-				if (pos[bytes] == '\\' || pos[bytes] == '\t' || pos[bytes] == '\n')
+		for (; buf.position() + bytes != buf.buffer().end(); ++bytes)
+			if (buf.position()[bytes] == '\\' || buf.position()[bytes] == '\t' || buf.position()[bytes] == '\n')
 				break;
 
-			s.append(pos, bytes);
-			pos += bytes;
+		s.append(buf.position(), bytes);
+		buf.position() += bytes;
 
-			if (*pos == '\t' || *pos == '\n')
+		if (*buf.position() == '\t' || *buf.position() == '\n')
 			return;
 
-			if (*pos == '\\')
+		if (*buf.position() == '\\')
 		{
-				++pos;
-				if (eof())
+			++buf.position();
+			if (buf.eof())
 				throw Exception("Cannot parse escape sequence", ErrorCodes::CANNOT_PARSE_ESCAPE_SEQUENCE);
-				s += parseEscapeSequence(*pos);
-				++pos;
+			s += parseEscapeSequence(*buf.position());
+			++buf.position();
 		}
 	}
 }
 
-	void readQuotedString(String & s)
+void readQuotedString(String & s, ReadBuffer & buf)
 {
 	s = "";
 
-		if (eof() || *pos != '\'')
+	if (buf.eof() || *buf.position() != '\'')
 		throw Exception("Cannot parse quoted string: expected opening single quote",
 			ErrorCodes::CANNOT_PARSE_QUOTED_STRING);
-		++pos;
+	++buf.position();
 
-		while (!eof())
+	while (!buf.eof())
 	{
 		size_t bytes = 0;
-			for (; pos + bytes != working_buffer.end(); ++bytes)
-				if (pos[bytes] == '\\' || pos[bytes] == '\'')
+		for (; buf.position() + bytes != buf.buffer().end(); ++bytes)
+			if (buf.position()[bytes] == '\\' || buf.position()[bytes] == '\'')
 				break;
 
-			s.append(pos, bytes);
-			pos += bytes;
+		s.append(buf.position(), bytes);
+		buf.position() += bytes;
 
-			if (*pos == '\'')
+		if (*buf.position() == '\'')
 		{
-				++pos;
+			++buf.position();
 			return;
 		}
 
-			if (*pos == '\\')
+		if (*buf.position() == '\\')
 		{
-				++pos;
-				if (eof())
+			++buf.position();
+			if (buf.eof())
 				throw Exception("Cannot parse escape sequence", ErrorCodes::CANNOT_PARSE_ESCAPE_SEQUENCE);
-				s += parseEscapeSequence(*pos);
-				++pos;
+			s += parseEscapeSequence(*buf.position());
+			++buf.position();
 		}
 	}
 
@@ -251,50 +354,6 @@ public:
 }
 
 
-	size_t read(char * to, size_t n)
-	{
-		size_t bytes_copied = 0;
-
-		while (!eof() && bytes_copied < n)
-		{
-			size_t bytes_to_copy = std::min(static_cast<size_t>(working_buffer.end() - pos), n - bytes_copied);
-			memcpy(to, pos, bytes_to_copy);
-			pos += bytes_to_copy;
-		}
-
-		return bytes_copied;
-	}
-
-
-	
-
-protected:
-	char internal_buffer[DEFAULT_READ_BUFFER_SIZE];
-	Buffer working_buffer;
-	Position pos;
-
-private:
-	inline char parseEscapeSequence(char c)
-	{
-		switch(c)
-		{
-			case 'b':
-				return '\b';
-			case 'f':
-				return '\f';
-			case 'n':
-				return '\n';
-			case 'r':
-				return '\r';
-			case 't':
-				return '\t';
-			default:
-				return c;
-		}
-	}
-};
-
-
 }
 
 #endif

dbms/include/DB/Core/WriteBuffer.h

@@ -0,0 +1,198 @@
+#ifndef DBMS_COMMON_WRITEBUFFER_H
+#define DBMS_COMMON_WRITEBUFFER_H
+
+#include <cstring>
+#include <cstdio>
+#include <limits>
+#include <algorithm>
+
+#include <DB/Core/Types.h>
+#include <DB/Core/Exception.h>
+#include <DB/Core/ErrorCodes.h>
+
+#define DEFAULT_WRITE_BUFFER_SIZE 1048576
+#define DEFAULT_FLOAT_PRECISION 6
+/// 20 цифр, знак, и \0 для конца строки
+#define MAX_INT_WIDTH 22
+
+
+namespace DB
+{
+
+/** Простой абстрактный класс для буферизованной записи данных (последовательности char) куда-нибудь.
+  * В отличие от std::ostream, предоставляет доступ к внутреннему буферу,
+  *  а также позволяет вручную управлять позицией внутри буфера.
+  *
+  * Наследники должны реализовать метод next().
+  *
+  * Также предоставляет набор функций для форматированной и неформатированной записи.
+  * (с простой и грубой реализацией)
+  */
+class WriteBuffer
+{
+public:
+	typedef char * Position;
+
+	struct Buffer
+	{
+		Buffer(Position begin_pos_, Position end_pos_) : begin_pos(begin_pos_), end_pos(end_pos_) {}
+
+		inline Position begin() { return begin_pos; }
+		inline Position end() { return end_pos; }
+
+	private:
+		Position begin_pos;
+		Position end_pos;		/// на 1 байт после конца буфера
+	};
+
+	WriteBuffer() : working_buffer(internal_buffer, internal_buffer + DEFAULT_WRITE_BUFFER_SIZE), pos(internal_buffer) {}
+
+	/// получить часть буфера, в который можно писать данные
+	inline Buffer & buffer() { return working_buffer; }
+	
+	/// получить (для чтения и изменения) позицию в буфере
+	inline Position & position() { return pos; };
+
+	/** записать данные, находящиеся в буфере (от начала буфера до текущей позиции);
+	  * переместить позицию в начало; кинуть исключение, если что-то не так
+	  */
+	virtual void next() {}
+
+	virtual ~WriteBuffer() {}
+
+
+	inline void nextIfAtEnd()
+	{
+		if (pos == working_buffer.end())
+			next();
+	}
+
+	
+	void write(const char * from, size_t n)
+	{
+		size_t bytes_copied = 0;
+
+		while (bytes_copied < n)
+		{
+			nextIfAtEnd();
+			size_t bytes_to_copy = std::min(static_cast<size_t>(working_buffer.end() - pos), n - bytes_copied);
+			std::memcpy(pos, from + bytes_copied, bytes_to_copy);
+			pos += bytes_to_copy;
+			bytes_copied += bytes_to_copy;
+		}
+	}
+
+protected:
+	char internal_buffer[DEFAULT_WRITE_BUFFER_SIZE];
+	Buffer working_buffer;
+	Position pos;
+};
+
+
+/// Функции-помошники для форматированной записи
+
+void writeChar(char x, WriteBuffer & buf)
+{
+	buf.nextIfAtEnd();
+	*buf.position() = x;
+	++buf.position();
+}
+
+
+template <typename T> struct IntFormat { static const char * format; };
+template <> const char * IntFormat<Int8>::format = "%hhi";
+template <> const char * IntFormat<Int16>::format = "%hi";
+template <> const char * IntFormat<Int32>::format = "%li";
+template <> const char * IntFormat<Int64>::format = "%lli";
+template <> const char * IntFormat<UInt8>::format = "%hhi";
+template <> const char * IntFormat<UInt16>::format = "%hi";
+template <> const char * IntFormat<UInt32>::format = "%li";
+template <> const char * IntFormat<UInt64>::format = "%lli";
+
+/// грубо
+template <typename T>
+void writeIntText(T x, WriteBuffer & buf)
+{
+	char tmp[MAX_INT_WIDTH];
+	int res = std::snprintf(tmp, MAX_INT_WIDTH, IntFormat<T>::format, x);
+
+	if (res >= MAX_INT_WIDTH || res <= 0)
+		throw Exception("Cannot print integer", ErrorCodes::CANNOT_PRINT_INTEGER);
+
+	buf.write(tmp, res - 1);
+}
+
+template <typename T>
+void writeFloatText(T x, WriteBuffer & buf, unsigned precision = DEFAULT_FLOAT_PRECISION)
+{
+	unsigned size = precision + 10;
+	char tmp[size];	/// знаки, +0.0e+123\0
+	int res = std::snprintf(tmp, size, "%.*g", precision, x);
+
+	if (res >= static_cast<int>(size) || res <= 0)
+		throw Exception("Cannot print float or double number", ErrorCodes::CANNOT_PRINT_FLOAT_OR_DOUBLE_NUMBER);
+
+	buf.write(tmp, res - 1);
+}
+
+void writeString(const String & s, WriteBuffer & buf)
+{
+	buf.write(s.data(), s.size());
+}
+
+/// предполагается, что строка в оперативке хранится непрерывно, и \0-terminated.
+void writeEscapedString(const String & s, WriteBuffer & buf)
+{
+	for (String::const_iterator it = s.begin(); it != s.end(); ++it)
+	{
+		switch (*it)
+		{
+			case '\b':
+				writeChar('\\', buf);
+				writeChar('b', buf);
+				break;
+			case '\f':
+				writeChar('\\', buf);
+				writeChar('f', buf);
+				break;
+			case '\n':
+				writeChar('\\', buf);
+				writeChar('n', buf);
+				break;
+			case '\r':
+				writeChar('\\', buf);
+				writeChar('r', buf);
+				break;
+			case '\t':
+				writeChar('\\', buf);
+				writeChar('t', buf);
+				break;
+			case '\0':
+				writeChar('\\', buf);
+				writeChar('0', buf);
+				break;
+			case '\'':
+				writeChar('\\', buf);
+				writeChar('\'', buf);
+				break;
+			case '\\':
+				writeChar('\\', buf);
+				writeChar('\\', buf);
+				break;
+			default:
+				writeChar(*it, buf);
+		}
+	}
+}
+
+void writeQuotedString(const String & s, WriteBuffer & buf)
+{
+	writeChar('\'', buf);
+	writeEscapedString(s, buf);
+	writeChar('\'', buf);
+}
+
+
+}
+
+#endif

dbms/include/DB/Core/WriteBufferFromOStream.h

@@ -0,0 +1,40 @@
+#ifndef DBMS_COMMON_WRITEBUFFER_FROM_OSTREAM_H
+#define DBMS_COMMON_WRITEBUFFER_FROM_OSTREAM_H
+
+#include <iostream>
+
+#include <DB/Core/Exception.h>
+#include <DB/Core/ErrorCodes.h>
+
+#include <DB/Core/WriteBuffer.h>
+
+
+namespace DB
+{
+
+class WriteBufferFromOStream : public WriteBuffer
+{
+private:
+	std::ostream & ostr;
+
+public:
+	WriteBufferFromOStream(std::ostream & ostr_) : ostr(ostr_) {}
+
+	void next()
+	{
+		ostr.write(internal_buffer, pos - internal_buffer);
+		pos = internal_buffer;
+
+		if (!ostr.good())
+			throw Exception("Cannot write to ostream", ErrorCodes::CANNOT_WRITE_TO_OSTREAM);
+	}
+
+	~WriteBufferFromOStream()
+	{
+		next();
+	}
+};
+
+}
+
+#endif

dbms/src/Core/tests/read_buffer.cpp

@@ -18,16 +18,16 @@ int main(int argc, char ** argv)
 		DB::Float64 b;
 		DB::String c, d;
 
-		in.readIntText(a);
+		DB::readIntText(a, in);
 		in.ignore();
 		
-		in.readFloatText(b);
+		DB::readFloatText(b, in);
 		in.ignore();
 		
-		in.readEscapedString(c);
+		DB::readEscapedString(c, in);
 		in.ignore();
 		
-		in.readQuotedString(d);
+		DB::readQuotedString(d, in);
 
 		std::cout << a << ' ' << b << ' ' << c << '\t' << '\'' << d << '\'' << std::endl;
 	}

dbms/src/Core/tests/read_buffer_perf.cpp

@@ -20,16 +20,16 @@ int main(int argc, char ** argv)
 		size_t i = 0;
 		while (!in.eof())
 		{
-			in.readIntText(a);
+			DB::readIntText(a, in);
 			in.ignore();
 			
-			in.readFloatText(b);
+			DB::readFloatText(b, in);
 			in.ignore();
 			
-			in.readEscapedString(c);
+			DB::readEscapedString(c, in);
 			in.ignore();
 			
-			in.readQuotedString(d);
+			DB::readQuotedString(d, in);
 			in.ignore();
 
 			++i;

dbms/src/Core/tests/write_buffer.cpp

@@ -0,0 +1,45 @@
+#include <string>
+
+#include <iostream>
+#include <sstream>
+
+#include <DB/Core/WriteBufferFromOStream.h>
+
+
+int main(int argc, char ** argv)
+{
+	try
+	{
+		DB::Int64 a = -123456;
+		DB::Float64 b = 123.456;
+		DB::String c = "вася пе\tтя";
+		DB::String d = "'xyz\\";
+
+		std::stringstream s;
+
+		{
+			DB::WriteBufferFromOStream out(s);
+
+			DB::writeIntText(a, out);
+			DB::writeChar(' ', out);
+			
+			DB::writeFloatText(b, out);
+			DB::writeChar(' ', out);
+			
+			DB::writeEscapedString(c, out);
+			DB::writeChar('\t', out);
+
+			DB::writeQuotedString(d, out);
+			DB::writeChar('\n', out);
+		}
+
+		std::cout << s.str();
+	}
+	catch (const DB::Exception & e)
+	{
+		std::cerr << e.what() << ", " << e.message() << std::endl;
+		return 1;
+	}
+
+	return 0;
+}

dbms/src/Core/tests/write_buffer_perf.cpp

@@ -0,0 +1,43 @@
+#include <string>
+
+#include <iostream>
+#include <fstream>
+
+#include <DB/Core/WriteBufferFromOStream.h>
+
+
+int main(int argc, char ** argv)
+{
+	try
+	{
+		DB::Int64 a = -123456;
+		DB::Float64 b = 123.456;
+		DB::String c = "вася пе\tтя";
+		DB::String d = "'xyz\\";
+
+		std::ofstream s("test");
+		DB::WriteBufferFromOStream out(s);
+
+		for (int i = 0; i < 1000000; ++i)
+		{
+			DB::writeIntText(a, out);
+			DB::writeChar(' ', out);
+			
+			DB::writeFloatText(b, out);
+			DB::writeChar(' ', out);
+			
+			DB::writeEscapedString(c, out);
+			DB::writeChar('\t', out);
+
+			DB::writeQuotedString(d, out);
+			DB::writeChar('\n', out);
+		}
+	}
+	catch (const DB::Exception & e)
+	{
+		std::cerr << e.what() << ", " << e.message() << std::endl;
+		return 1;
+	}
+
+	return 0;
+}