thevar1able/ClickHouse
1
0
Fork 0
mirror of https://github.com/ClickHouse/ClickHouse.git synced 2024-11-21 23:21:59 +00:00
Code Issues Packages Projects Releases Wiki Activity

dbms: development [#CONV-2944].

Browse Source
This commit is contained in:
Alexey Milovidov 2011-08-14 01:11:33 +00:00
parent 987784ed80
commit 47453e759f
2 changed files with 19 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
dbms/src/DataStreams/LimitBlockInputStream.cpp
View File

@ -36,10 +36,14 @@ Block LimitBlockInputStream::read()
return res;
/// отдать кусок блока
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)));
size_t start = std::max(
static_cast<Int64>(0),
static_cast<Int64>(offset) - static_cast<Int64>(pos) + static_cast<Int64>(rows));
size_t length = std::min(
static_cast<Int64>(limit), std::min(
static_cast<Int64>(pos) - static_cast<Int64>(offset),
static_cast<Int64>(limit) + static_cast<Int64>(offset) - static_cast<Int64>(pos) + static_cast<Int64>(rows)));
for (size_t i = 0; i < res.columns(); ++i)
res.getByPosition(i).column->cut(start, length);

19
dbms/src/DataStreams/tests/expression_stream.cpp
View File

@ -3,6 +3,7 @@
#include <Poco/SharedPtr.h>
#include <Poco/Stopwatch.h>
#include <Poco/NumberParser.h>
#include <DB/IO/WriteBufferFromOStream.h>
@ -19,6 +20,7 @@
#include <DB/Parsers/ParserSelectQuery.h>
using Poco::SharedPtr;
@ -26,16 +28,11 @@ 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");
size_t n = argc == 2 ? Poco::NumberParser::parseUnsigned64(argv[1]) : 10ULL;
DB::ParserSelectQuery parser;
DB::ASTPtr ast;
std::string input = "SELECT number, number + 1, number * 2, number * 2 + 1";
std::string input = "SELECT number, number / 3, number * number";
std::string expected;
const char * begin = input.data();
@ -53,13 +50,19 @@ int main(int argc, char ** argv)
context.columns["number"] = new DB::DataTypeUInt64;
context.functions["plus"] = new DB::FunctionPlus;
context.functions["multiply"] = new DB::FunctionMultiply;
context.functions["divide"] = new DB::FunctionDivideFloating;
Poco::SharedPtr<DB::Expression> expression = new DB::Expression(ast, context);
DB::StorageSystemNumbers table;
DB::Names column_names;
column_names.push_back("number");
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::LimitBlockInputStream in3(in2, 10, std::max(static_cast<Int64>(0), static_cast<Int64>(n) - 10));
DB::WriteBufferFromOStream out1(std::cout);
DB::TabSeparatedRowOutputStream out2(out1, new DB::DataTypes(expression->getReturnTypes()));