dbms: development [#CONV-2944].

dbms/include/DB/Core/Block.h

@@ -62,6 +62,9 @@ public:
 
 	operator bool() const { return !data.empty(); }
 	bool operator!() const { return data.empty(); }
+
+	/** Получить список имён столбцов через запятую. */
+	std::string dumpNames() const;
 };
 
 }

dbms/include/DB/DataStreams/ExpressionBlockInputStream.h

@@ -0,0 +1,41 @@
+#pragma once
+
+#include <Poco/SharedPtr.h>
+
+#include <DB/Interpreters/Expression.h>
+#include <DB/DataStreams/IBlockInputStream.h>
+
+
+namespace DB
+{
+
+using Poco::SharedPtr;
+
+
+/** Выполняет над блоком вычисление некоторого выражения.
+  * Выражение состоит из идентификаторов столбцов из блока, констант, обычных функций.
+  * Например: hits * 2 + 3, instr("yandex", url)
+  * Выражение не меняет количество строк в потоке, и обрабатывает каждую строку независимо от других.
+  */
+class ExpressionBlockInputStream : public IBlockInputStream
+{
+public:
+	ExpressionBlockInputStream(SharedPtr<IBlockInputStream> input_, SharedPtr<Expression> expression_)
+		: input(input_), expression(expression_) {}
+
+	Block read()
+	{
+		Block res = input->read();
+		if (!res)
+			return res;
+
+		expression->execute(res);
+		return res;
+	}
+
+private:
+	SharedPtr<IBlockInputStream> input;
+	SharedPtr<Expression> expression;
+};
+
+}

dbms/include/DB/Interpreters/Expression.h

@@ -29,6 +29,10 @@ public:
 	  */
 	void execute(Block & block);
 
+	/** Получить список типов столбцов результата.
+	  */
+	DataTypes getReturnTypes();
+
 private:
 	ASTPtr ast;
 	const Context & context;
@@ -67,6 +71,8 @@ private:
 	Block projectResult(ASTPtr ast, Block & block);
 
 	void collectFinalColumns(ASTPtr ast, Block & src, Block & dst);
+
+	void getReturnTypesImpl(ASTPtr ast, DataTypes & res);
 };
 
 

dbms/src/Core/Block.cpp

@@ -44,7 +44,8 @@ void Block::rebuildIndexByPosition()
 void Block::insert(size_t position, const ColumnWithNameAndType & elem)
 {
 	if (position >= index_by_position.size())
-		throw Exception("Position out of bound in Block::insert()", ErrorCodes::POSITION_OUT_OF_BOUND);
+		throw Exception("Position out of bound in Block::insert(), max position = "
+			+ Poco::NumberFormatter::format(index_by_position.size()), ErrorCodes::POSITION_OUT_OF_BOUND);
 		
 	Container_t::iterator it = data.insert(index_by_position[position], elem);
 	rebuildIndexByPosition();
@@ -63,7 +64,8 @@ void Block::insert(const ColumnWithNameAndType & elem)
 void Block::erase(size_t position)
 {
 	if (position >= index_by_position.size())
-		throw Exception("Position out of bound in Block::erase()", ErrorCodes::POSITION_OUT_OF_BOUND);
+		throw Exception("Position out of bound in Block::erase(), max position = "
+			+ Poco::NumberFormatter::format(index_by_position.size()), ErrorCodes::POSITION_OUT_OF_BOUND);
 		
 	Container_t::iterator it = index_by_position[position];
 	index_by_name.erase(index_by_name.find(it->name));
@@ -94,7 +96,8 @@ const ColumnWithNameAndType & Block::getByName(const std::string & name) const
 {
 	IndexByName_t::const_iterator it = index_by_name.find(name);
 	if (index_by_name.end() == it)
-		throw Exception("Not found column " + name + " in block.", ErrorCodes::NOT_FOUND_COLUMN_IN_BLOCK);
+		throw Exception("Not found column " + name + " in block. There are only columns: " + dumpNames()
+			, ErrorCodes::NOT_FOUND_COLUMN_IN_BLOCK);
 
 	return *it->second;
 }
@@ -104,7 +107,8 @@ size_t Block::getPositionByName(const std::string & name) const
 {
 	IndexByName_t::const_iterator it = index_by_name.find(name);
 	if (index_by_name.end() == it)
-		throw Exception("Not found column " + name + " in block.", ErrorCodes::NOT_FOUND_COLUMN_IN_BLOCK);
+		throw Exception("Not found column " + name + " in block. There are only columns: " + dumpNames()
+			, ErrorCodes::NOT_FOUND_COLUMN_IN_BLOCK);
 
 	return std::distance(const_cast<Container_t &>(data).begin(), it->second);
 }
@@ -118,10 +122,13 @@ size_t Block::rows() const
 		size_t size = it->column->size();
 
 		if (size == 0)
-			throw Exception("Empty column in block.", ErrorCodes::EMPTY_COLUMN_IN_BLOCK);
+			throw Exception("Empty column " + it->name + " in block.", ErrorCodes::EMPTY_COLUMN_IN_BLOCK);
 
 		if (res != 0 && size != res)
-			throw Exception("Sizes of columns doesn't match.", ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
+			throw Exception("Sizes of columns doesn't match: "
+				+ data.begin()->name + ": " + Poco::NumberFormatter::format(res)
+				+ ", " + it->name + ": " + Poco::NumberFormatter::format(size)
+				, ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
 
 		res = size;
 	}
@@ -135,4 +142,18 @@ size_t Block::columns() const
 	return data.size();
 }
 
+
+std::string Block::dumpNames() const
+{
+	std::stringstream res;
+	for (Container_t::const_iterator it = data.begin(); it != data.end(); ++it)
+	{
+		if (it != data.begin())
+			res << ", ";
+		res << it->name;
+	}
+	return res.str();
+}
+
+
 }

dbms/src/DataStreams/LimitBlockInputStream.cpp

@@ -36,9 +36,11 @@ Block LimitBlockInputStream::read()
 		return res;
 
 	/// отдать кусок блока
-	size_t start = std::max(0, static_cast<int>(offset) + static_cast<int>(rows) - static_cast<int>(pos));
-	size_t length = std::min(rows - start, limit + offset + rows - pos);
-	
+	size_t start = std::max(0, static_cast<int>(offset) - static_cast<int>(pos) + static_cast<int>(rows));
+	size_t length = std::min(static_cast<int>(limit), std::min(
+		static_cast<int>(pos) - static_cast<int>(offset),
+		static_cast<int>(limit) + static_cast<int>(offset) - static_cast<int>(pos) + static_cast<int>(rows)));
+
 	for (size_t i = 0; i < res.columns(); ++i)
 		res.getByPosition(i).column->cut(start, length);
 	

dbms/src/DataStreams/tests/expression_stream.cpp

@@ -0,0 +1,87 @@
+#include <iostream>
+#include <iomanip>
+
+#include <Poco/SharedPtr.h>
+#include <Poco/Stopwatch.h>
+
+#include <DB/IO/WriteBufferFromOStream.h>
+
+#include <DB/Storages/StorageSystemNumbers.h>
+
+#include <DB/DataStreams/LimitBlockInputStream.h>
+#include <DB/DataStreams/ExpressionBlockInputStream.h>
+#include <DB/DataStreams/TabSeparatedRowOutputStream.h>
+#include <DB/DataStreams/copyData.h>
+
+#include <DB/DataTypes/DataTypesNumberFixed.h>
+
+#include <DB/Functions/FunctionsArithmetic.h>
+
+#include <DB/Parsers/ParserSelectQuery.h>
+
+using Poco::SharedPtr;
+
+
+int main(int argc, char ** argv)
+{
+	try
+	{
+		size_t n = argc == 2 ? atoi(argv[1]) : 10;
+		
+		DB::StorageSystemNumbers table;
+
+		DB::Names column_names;
+		column_names.push_back("number");
+
+		DB::ParserSelectQuery parser;
+		DB::ASTPtr ast;
+		std::string input = "SELECT number, number + 1, number * 2, number * 2 + 1";
+		std::string expected;
+
+		const char * begin = input.data();
+		const char * end = begin + input.size();
+		const char * pos = begin;
+
+		if (!parser.parse(pos, end, ast, expected))
+		{
+			std::cout << "Failed at position " << (pos - begin) << ": "
+				<< mysqlxx::quote << input.substr(pos - begin, 10)
+				<< ", expected " << expected << "." << std::endl;
+		}
+
+		DB::Context context;
+		context.columns["number"] = new DB::DataTypeUInt64;
+		context.functions["plus"] = new DB::FunctionPlus;
+		context.functions["multiply"] = new DB::FunctionMultiply;
+
+		Poco::SharedPtr<DB::Expression> expression = new DB::Expression(ast, context);
+
+		Poco::SharedPtr<DB::IBlockInputStream> in1(table.read(column_names, 0));
+
+		Poco::SharedPtr<DB::ExpressionBlockInputStream> in2 = new DB::ExpressionBlockInputStream(in1, expression);
+		DB::LimitBlockInputStream in3(in2, 10, std::max(0, static_cast<int>(n) - 10));
+		
+		DB::WriteBufferFromOStream out1(std::cout);
+		DB::TabSeparatedRowOutputStream out2(out1, new DB::DataTypes(expression->getReturnTypes()));
+
+		{
+			Poco::Stopwatch stopwatch;
+			stopwatch.start();
+
+			DB::copyData(in3, out2);
+
+			stopwatch.stop();
+			std::cout << std::fixed << std::setprecision(2)
+				<< "Elapsed " << stopwatch.elapsed() / 1000000.0 << " sec."
+				<< ", " << n * 1000000 / stopwatch.elapsed() << " rows/sec."
+				<< std::endl;
+		}
+	}
+	catch (const DB::Exception & e)
+	{
+		std::cerr << e.what() << ", " << e.message() << std::endl;
+		return 1;
+	}
+
+	return 0;
+}

dbms/src/Interpreters/Expression.cpp

@@ -136,7 +136,7 @@ void Expression::executeImpl(ASTPtr ast, Block & block)
 
 	if (ASTFunction * node = dynamic_cast<ASTFunction *>(&*ast))
 	{
-		std::cerr << node->getTreeID() << std::endl;
+		//std::cerr << node->getTreeID() << std::endl;
 		
 		/// Вставляем в блок столбцы - результаты вычисления функции
 		ColumnNumbers argument_numbers;
@@ -170,7 +170,7 @@ void Expression::executeImpl(ASTPtr ast, Block & block)
 	}
 	else if (ASTLiteral * node = dynamic_cast<ASTLiteral *>(&*ast))
 	{
-		std::cerr << node->getTreeID() << std::endl;
+		//std::cerr << node->getTreeID() << std::endl;
 				
 		/// Вставляем в блок столбец - константу
 		
@@ -214,5 +214,33 @@ void Expression::collectFinalColumns(ASTPtr ast, Block & src, Block & dst)
 			 collectFinalColumns(*it, src, dst);
 }
 
+
+DataTypes Expression::getReturnTypes()
+{
+	DataTypes res;
+	getReturnTypesImpl(ast, res);
+	return res;
+}
+
+
+void Expression::getReturnTypesImpl(ASTPtr ast, DataTypes & res)
+{
+	if (ASTExpressionList * node = dynamic_cast<ASTExpressionList *>(&*ast))
+	{
+		for (ASTs::iterator it = node->children.begin(); it != node->children.end(); ++it)
+		{
+			if (ASTIdentifier * ident = dynamic_cast<ASTIdentifier *>(&**it))
+				res.push_back(ident->type);
+			else if (ASTFunction * func = dynamic_cast<ASTFunction *>(&**it))
+				res.insert(res.end(), func->return_types.begin(), func->return_types.end());
+			else if (ASTLiteral * lit = dynamic_cast<ASTLiteral *>(&**it))
+				res.push_back(lit->type);
+		}
+	}
+	else
+		for (ASTs::iterator it = ast->children.begin(); it != ast->children.end(); ++it)
+			 getReturnTypesImpl(*it, res);
+}
+
 	
 }

dbms/src/Storages/StorageSystemNumbers.cpp

@@ -21,9 +21,8 @@ NumbersBlockInputStream::NumbersBlockInputStream(size_t block_size_) : block_siz
 Block NumbersBlockInputStream::read()
 {
 	Block res;
-	res.insert(ColumnWithNameAndType());
-
-	ColumnWithNameAndType & column_with_name_and_type = res.getByPosition(0);
+	
+	ColumnWithNameAndType column_with_name_and_type;
 	
 	column_with_name_and_type.name = "number";
 	column_with_name_and_type.type = new DataTypeUInt64();
@@ -33,6 +32,8 @@ Block NumbersBlockInputStream::read()
 
 	for (size_t i = 0; i < block_size; ++i)
 		vec[i] = next++;
+
+	res.insert(column_with_name_and_type);
 	
 	return res;
 }