ClickHouse/dbms/src/Core/Block.cpp
2017-05-22 18:40:11 +04:00

619 lines
18 KiB
C++

#include <Common/Exception.h>
#include <Core/Block.h>
#include <Columns/ColumnArray.h>
#include <Columns/ColumnNullable.h>
#include <Columns/ColumnTuple.h>
#include <DataTypes/DataTypeNested.h>
#include <DataTypes/DataTypeArray.h>
#include <DataTypes/DataTypesNumber.h>
#include <IO/WriteBufferFromString.h>
#include <IO/Operators.h>
#include <iterator>
#include <memory>
namespace DB
{
namespace ErrorCodes
{
extern const int POSITION_OUT_OF_BOUND;
extern const int NOT_FOUND_COLUMN_IN_BLOCK;
extern const int SIZES_OF_COLUMNS_DOESNT_MATCH;
extern const int SIZES_OF_ARRAYS_DOESNT_MATCH;
}
void Block::addDefaults(const NamesAndTypesList & required_columns)
{
/// For missing columns of nested structure, you need to create not a column of empty arrays, but a column of arrays of correct lengths.
/// First, remember the offset columns for all arrays in the block.
std::map<String, ColumnPtr> offset_columns;
for (const auto & elem : data)
{
if (const ColumnArray * array = typeid_cast<const ColumnArray *>(&*elem.column))
{
String offsets_name = DataTypeNested::extractNestedTableName(elem.name);
auto & offsets_column = offset_columns[offsets_name];
/// If for some reason there are different displacement columns for one nested structure, then we take nonempty.
if (!offsets_column || offsets_column->empty())
offsets_column = array->getOffsetsColumn();
}
}
for (const auto & requested_column : required_columns)
{
if (has(requested_column.name))
continue;
ColumnWithTypeAndName column_to_add;
column_to_add.name = requested_column.name;
column_to_add.type = requested_column.type;
String offsets_name = DataTypeNested::extractNestedTableName(column_to_add.name);
if (offset_columns.count(offsets_name))
{
ColumnPtr offsets_column = offset_columns[offsets_name];
DataTypePtr nested_type = typeid_cast<DataTypeArray &>(*column_to_add.type).getNestedType();
size_t nested_rows = offsets_column->empty() ? 0
: typeid_cast<ColumnUInt64 &>(*offsets_column).getData().back();
ColumnPtr nested_column = dynamic_cast<IColumnConst &>(
*nested_type->createConstColumn(
nested_rows, nested_type->getDefault())).convertToFullColumn();
column_to_add.column = std::make_shared<ColumnArray>(nested_column, offsets_column);
}
else
{
/** It is necessary to turn a constant column into a full column, since in part of blocks (from other parts),
* it can be full (or the interpreter may decide that it is constant everywhere).
*/
column_to_add.column = dynamic_cast<IColumnConst &>(
*column_to_add.type->createConstColumn(
rows(), column_to_add.type->getDefault())).convertToFullColumn();
}
insert(std::move(column_to_add));
}
}
Block::Block(std::initializer_list<ColumnWithTypeAndName> il) : data{il}
{
initializeIndexByName();
}
Block::Block(const ColumnsWithTypeAndName & data_) : data{data_}
{
initializeIndexByName();
}
void Block::initializeIndexByName()
{
for (size_t i = 0, size = data.size(); i < size; ++i)
index_by_name[data[i].name] = i;
}
void Block::insert(size_t position, const ColumnWithTypeAndName & elem)
{
if (position > data.size())
throw Exception("Position out of bound in Block::insert(), max position = "
+ toString(data.size()), ErrorCodes::POSITION_OUT_OF_BOUND);
for (auto & name_pos : index_by_name)
if (name_pos.second >= position)
++name_pos.second;
index_by_name[elem.name] = position;
data.emplace(data.begin() + position, elem);
}
void Block::insert(size_t position, ColumnWithTypeAndName && elem)
{
if (position > data.size())
throw Exception("Position out of bound in Block::insert(), max position = "
+ toString(data.size()), ErrorCodes::POSITION_OUT_OF_BOUND);
for (auto & name_pos : index_by_name)
if (name_pos.second >= position)
++name_pos.second;
index_by_name[elem.name] = position;
data.emplace(data.begin() + position, std::move(elem));
}
void Block::insert(const ColumnWithTypeAndName & elem)
{
index_by_name[elem.name] = data.size();
data.emplace_back(elem);
}
void Block::insert(ColumnWithTypeAndName && elem)
{
index_by_name[elem.name] = data.size();
data.emplace_back(std::move(elem));
}
void Block::insertUnique(const ColumnWithTypeAndName & elem)
{
if (index_by_name.end() == index_by_name.find(elem.name))
insert(elem);
}
void Block::insertUnique(ColumnWithTypeAndName && elem)
{
if (index_by_name.end() == index_by_name.find(elem.name))
insert(std::move(elem));
}
void Block::erase(size_t position)
{
if (data.empty())
throw Exception("Block is empty", ErrorCodes::POSITION_OUT_OF_BOUND);
if (position >= data.size())
throw Exception("Position out of bound in Block::erase(), max position = "
+ toString(data.size() - 1), ErrorCodes::POSITION_OUT_OF_BOUND);
eraseImpl(position);
}
void Block::eraseImpl(size_t position)
{
data.erase(data.begin() + position);
for (auto it = index_by_name.begin(); it != index_by_name.end();)
{
if (it->second == position)
index_by_name.erase(it++);
else
{
if (it->second > position)
--it->second;
++it;
}
}
}
void Block::erase(const String & name)
{
auto index_it = index_by_name.find(name);
if (index_it == index_by_name.end())
throw Exception("No such name in Block::erase(): '"
+ name + "'", ErrorCodes::NOT_FOUND_COLUMN_IN_BLOCK);
eraseImpl(index_it->second);
}
ColumnWithTypeAndName & Block::safeGetByPosition(size_t position)
{
if (data.empty())
throw Exception("Block is empty", ErrorCodes::POSITION_OUT_OF_BOUND);
if (position >= data.size())
throw Exception("Position " + toString(position)
+ " is out of bound in Block::safeGetByPosition(), max position = "
+ toString(data.size() - 1)
+ ", there are columns: " + dumpNames(), ErrorCodes::POSITION_OUT_OF_BOUND);
return data[position];
}
const ColumnWithTypeAndName & Block::safeGetByPosition(size_t position) const
{
if (data.empty())
throw Exception("Block is empty", ErrorCodes::POSITION_OUT_OF_BOUND);
if (position >= data.size())
throw Exception("Position " + toString(position)
+ " is out of bound in Block::safeGetByPosition(), max position = "
+ toString(data.size() - 1)
+ ", there are columns: " + dumpNames(), ErrorCodes::POSITION_OUT_OF_BOUND);
return data[position];
}
ColumnWithTypeAndName & Block::getByName(const std::string & name)
{
auto it = index_by_name.find(name);
if (index_by_name.end() == it)
throw Exception("Not found column " + name + " in block. There are only columns: " + dumpNames()
, ErrorCodes::NOT_FOUND_COLUMN_IN_BLOCK);
return data[it->second];
}
const ColumnWithTypeAndName & Block::getByName(const std::string & name) const
{
auto it = index_by_name.find(name);
if (index_by_name.end() == it)
throw Exception("Not found column " + name + " in block. There are only columns: " + dumpNames()
, ErrorCodes::NOT_FOUND_COLUMN_IN_BLOCK);
return data[it->second];
}
bool Block::has(const std::string & name) const
{
return index_by_name.end() != index_by_name.find(name);
}
size_t Block::getPositionByName(const std::string & name) const
{
auto it = index_by_name.find(name);
if (index_by_name.end() == it)
throw Exception("Not found column " + name + " in block. There are only columns: " + dumpNames()
, ErrorCodes::NOT_FOUND_COLUMN_IN_BLOCK);
return it->second;
}
void Block::checkNumberOfRows() const
{
ssize_t rows = -1;
for (const auto & elem : data)
{
if (!elem.column)
throw Exception("Column " + elem.name + " in block is nullptr, in method checkNumberOfRows."
, ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
ssize_t size = elem.column->size();
if (rows == -1)
rows = size;
else if (rows != size)
throw Exception("Sizes of columns doesn't match: "
+ data.front().name + ": " + toString(rows)
+ ", " + elem.name + ": " + toString(size)
, ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
}
}
size_t Block::rows() const
{
for (const auto & elem : data)
if (elem.column)
return elem.column->size();
return 0;
}
size_t Block::bytes() const
{
size_t res = 0;
for (const auto & elem : data)
res += elem.column->byteSize();
return res;
}
std::string Block::dumpNames() const
{
std::string res;
{
WriteBufferFromString out(res);
for (auto it = data.begin(); it != data.end(); ++it)
{
if (it != data.begin())
out << ", ";
out << it->name;
}
}
return res;
}
std::string Block::dumpStructure() const
{
std::string res;
{
WriteBufferFromString out(res);
for (auto it = data.begin(); it != data.end(); ++it)
{
if (it != data.begin())
out << ", ";
out << it->name << ' ' << it->type->getName();
if (it->column)
out << ' ' << it->column->getName() << ' ' << it->column->size();
else
out << " nullptr";
}
}
return res;
}
Block Block::cloneEmpty() const
{
Block res;
for (const auto & elem : data)
res.insert(elem.cloneEmpty());
return res;
}
Block Block::sortColumns() const
{
Block sorted_block;
for (const auto & name : index_by_name)
sorted_block.insert(data[name.second]);
return sorted_block;
}
ColumnsWithTypeAndName Block::getColumns() const
{
return data;
}
NamesAndTypesList Block::getColumnsList() const
{
NamesAndTypesList res;
for (const auto & elem : data)
res.push_back(NameAndTypePair(elem.name, elem.type));
return res;
}
void Block::checkNestedArraysOffsets() const
{
/// Pointers to array columns, to check the equality of offset columns in nested data structures
using ArrayColumns = std::map<String, const ColumnArray *>;
ArrayColumns array_columns;
for (const auto & elem : data)
{
const IColumn * observed_col;
if (elem.column->isNullable())
{
const auto & nullable_col = static_cast<const ColumnNullable &>(*elem.column);
observed_col = nullable_col.getNestedColumn().get();
}
else
observed_col = elem.column.get();
if (const ColumnArray * column_array = typeid_cast<const ColumnArray *>(observed_col))
{
String name = DataTypeNested::extractNestedTableName(elem.name);
ArrayColumns::const_iterator it = array_columns.find(name);
if (array_columns.end() == it)
array_columns[name] = column_array;
else
{
if (!it->second->hasEqualOffsets(*column_array))
throw Exception("Sizes of nested arrays do not match", ErrorCodes::SIZES_OF_ARRAYS_DOESNT_MATCH);
}
}
}
}
void Block::optimizeNestedArraysOffsets()
{
/// Pointers to array columns, to check the equality of offset columns in nested data structures
using ArrayColumns = std::map<String, ColumnArray *>;
ArrayColumns array_columns;
for (auto & elem : data)
{
IColumn * observed_col;
if (elem.column->isNullable())
{
auto & nullable_col = static_cast<ColumnNullable &>(*elem.column);
observed_col = nullable_col.getNestedColumn().get();
}
else
observed_col = elem.column.get();
if (ColumnArray * column_array = typeid_cast<ColumnArray *>(observed_col))
{
String name = DataTypeNested::extractNestedTableName(elem.name);
ArrayColumns::const_iterator it = array_columns.find(name);
if (array_columns.end() == it)
array_columns[name] = column_array;
else
{
if (!it->second->hasEqualOffsets(*column_array))
throw Exception("Sizes of nested arrays do not match", ErrorCodes::SIZES_OF_ARRAYS_DOESNT_MATCH);
/// make columns of arrays offsets inside one nested table point to the same place
column_array->getOffsetsColumn() = it->second->getOffsetsColumn();
}
}
}
}
bool blocksHaveEqualStructure(const Block & lhs, const Block & rhs)
{
size_t columns = lhs.columns();
if (rhs.columns() != columns)
return false;
for (size_t i = 0; i < columns; ++i)
{
const IDataType & lhs_type = *lhs.safeGetByPosition(i).type;
const IDataType & rhs_type = *rhs.safeGetByPosition(i).type;
if (lhs_type.getName() != rhs_type.getName())
return false;
}
return true;
}
void getBlocksDifference(const Block & lhs, const Block & rhs, std::string & out_lhs_diff, std::string & out_rhs_diff)
{
/// The traditional task: the largest common subsequence (LCS).
/// Assume that order is important. If this becomes wrong once, let's simplify it: for example, make 2 sets.
std::vector<std::vector<int>> lcs(lhs.columns() + 1);
for (auto & v : lcs)
v.resize(rhs.columns() + 1);
for (size_t i = 1; i <= lhs.columns(); ++i)
{
for (size_t j = 1; j <= rhs.columns(); ++j)
{
if (lhs.safeGetByPosition(i - 1) == rhs.safeGetByPosition(j - 1))
lcs[i][j] = lcs[i - 1][j - 1] + 1;
else
lcs[i][j] = std::max(lcs[i - 1][j], lcs[i][j - 1]);
}
}
/// Now go back and collect the answer.
ColumnsWithTypeAndName left_columns;
ColumnsWithTypeAndName right_columns;
size_t l = lhs.columns();
size_t r = rhs.columns();
while (l > 0 && r > 0)
{
if (lhs.safeGetByPosition(l - 1) == rhs.safeGetByPosition(r - 1))
{
/// This element is in both sequences, so it does not get into `diff`.
--l;
--r;
}
else
{
/// Small heuristics: most often used when getting a difference for (expected_block, actual_block).
/// Therefore, the preference will be given to the field, which is in the left block (expected_block), therefore
/// in `diff` the column from `actual_block` will get.
if (lcs[l][r - 1] >= lcs[l - 1][r])
right_columns.push_back(rhs.safeGetByPosition(--r));
else
left_columns.push_back(lhs.safeGetByPosition(--l));
}
}
while (l > 0)
left_columns.push_back(lhs.safeGetByPosition(--l));
while (r > 0)
right_columns.push_back(rhs.safeGetByPosition(--r));
WriteBufferFromString lhs_diff_writer(out_lhs_diff);
WriteBufferFromString rhs_diff_writer(out_rhs_diff);
for (auto it = left_columns.rbegin(); it != left_columns.rend(); ++it)
{
lhs_diff_writer << it->prettyPrint();
lhs_diff_writer << ", position: " << lhs.getPositionByName(it->name) << '\n';
}
for (auto it = right_columns.rbegin(); it != right_columns.rend(); ++it)
{
rhs_diff_writer << it->prettyPrint();
rhs_diff_writer << ", position: " << rhs.getPositionByName(it->name) << '\n';
}
}
void Block::clear()
{
info = BlockInfo();
data.clear();
index_by_name.clear();
}
void Block::swap(Block & other) noexcept
{
std::swap(info, other.info);
data.swap(other.data);
index_by_name.swap(other.index_by_name);
}
void Block::unshareColumns()
{
std::unordered_set<void*> pointers;
for (auto & elem : data)
{
if (!pointers.insert(elem.column.get()).second)
{
elem.column = elem.column->clone();
}
else if (ColumnArray * arr = typeid_cast<ColumnArray *>(elem.column.get()))
{
ColumnPtr & offsets = arr->getOffsetsColumn();
if (!pointers.insert(offsets.get()).second)
offsets = offsets->clone();
ColumnPtr & nested = arr->getDataPtr();
if (!pointers.insert(nested.get()).second)
nested = nested->clone();
}
else if (ColumnTuple * tuple = typeid_cast<ColumnTuple *>(elem.column.get()))
{
Block & tuple_block = tuple->getData();
Columns & tuple_columns = tuple->getColumns();
size_t size = tuple_block.columns();
for (size_t i = 0; i < size; ++i)
{
if (!pointers.insert(tuple_columns[i].get()).second)
{
tuple_columns[i] = tuple_columns[i]->clone();
tuple_block.getByPosition(i).column = tuple_columns[i];
}
}
}
else if (ColumnNullable * nullable = typeid_cast<ColumnNullable *>(elem.column.get()))
{
ColumnPtr & null_map = nullable->getNullMapColumn();
if (!pointers.insert(null_map.get()).second)
null_map = null_map->clone();
ColumnPtr & nested = nullable->getNestedColumn();
if (!pointers.insert(nested.get()).second)
nested = nested->clone();
}
}
}
void Block::updateHash(SipHash & hash) const
{
for (size_t row_no = 0, num_rows = rows(); row_no < num_rows; ++row_no)
{
for (auto & col : getColumns())
col.column->updateHashWithValue(row_no, hash);
}
}
}