ClickHouse/dbms/src/Storages/ColumnsDescription.cpp
2019-05-02 00:43:05 +03:00

405 lines
12 KiB
C++

#include <Storages/ColumnsDescription.h>
#include <Parsers/ASTLiteral.h>
#include <Parsers/ExpressionElementParsers.h>
#include <Parsers/ExpressionListParsers.h>
#include <Parsers/ParserCreateQuery.h>
#include <Parsers/parseQuery.h>
#include <Parsers/queryToString.h>
#include <IO/WriteBuffer.h>
#include <IO/WriteHelpers.h>
#include <IO/ReadBuffer.h>
#include <IO/ReadHelpers.h>
#include <IO/WriteBufferFromString.h>
#include <IO/ReadBufferFromString.h>
#include <DataTypes/DataTypeFactory.h>
#include <DataTypes/NestedUtils.h>
#include <DataTypes/DataTypeArray.h>
#include <DataTypes/DataTypeTuple.h>
#include <Common/Exception.h>
#include <Interpreters/Context.h>
#include <Storages/IStorage.h>
#include <Common/typeid_cast.h>
#include <Compression/CompressionFactory.h>
namespace DB
{
namespace ErrorCodes
{
extern const int NO_SUCH_COLUMN_IN_TABLE;
extern const int ILLEGAL_COLUMN;
extern const int CANNOT_PARSE_TEXT;
}
bool ColumnDescription::operator==(const ColumnDescription & other) const
{
auto codec_str = [](const CompressionCodecPtr & codec_ptr) { return codec_ptr ? codec_ptr->getCodecDesc() : String(); };
auto ttl_str = [](const ASTPtr & ttl_ast) { return ttl_ast ? queryToString(ttl_ast) : String{}; };
return name == other.name
&& type->equals(*other.type)
&& default_desc == other.default_desc
&& comment == other.comment
&& codec_str(codec) == codec_str(other.codec)
&& ttl_str(ttl) == ttl_str(other.ttl);
}
void ColumnDescription::writeText(WriteBuffer & buf) const
{
writeBackQuotedString(name, buf);
writeChar(' ', buf);
DB::writeText(type->getName(), buf);
if (default_desc.expression)
{
writeChar('\t', buf);
DB::writeText(DB::toString(default_desc.kind), buf);
writeChar('\t', buf);
DB::writeText(queryToString(default_desc.expression), buf);
}
if (!comment.empty())
{
writeChar('\t', buf);
DB::writeText("COMMENT ", buf);
DB::writeText(queryToString(ASTLiteral(Field(comment))), buf);
}
if (codec)
{
writeChar('\t', buf);
DB::writeText("CODEC(", buf);
DB::writeText(codec->getCodecDesc(), buf);
DB::writeText(")", buf);
}
if (ttl)
{
writeChar('\t', buf);
DB::writeText("TTL ", buf);
DB::writeText(queryToString(ttl), buf);
}
writeChar('\n', buf);
}
void ColumnDescription::readText(ReadBuffer & buf)
{
ParserColumnDeclaration column_parser(true);
String column_line;
readEscapedStringUntilEOL(column_line, buf);
ASTPtr ast = parseQuery(column_parser, column_line, "column parser", 0);
if (const auto * col_ast = ast->as<ASTColumnDeclaration>())
{
name = col_ast->name;
type = DataTypeFactory::instance().get(col_ast->type);
if (col_ast->default_expression)
{
default_desc.kind = columnDefaultKindFromString(col_ast->default_specifier);
default_desc.expression = std::move(col_ast->default_expression);
}
if (col_ast->comment)
comment = col_ast->comment->as<ASTLiteral &>().value.get<String>();
if (col_ast->codec)
codec = CompressionCodecFactory::instance().get(col_ast->codec, type);
if (col_ast->ttl)
ttl = col_ast->ttl;
}
else
throw Exception("Cannot parse column description", ErrorCodes::CANNOT_PARSE_TEXT);
}
ColumnsDescription::ColumnsDescription(NamesAndTypesList ordinary)
{
for (auto & elem : ordinary)
add(ColumnDescription(std::move(elem.name), std::move(elem.type)));
}
/// We are trying to find first column from end with name `column_name` or with a name beginning with `column_name` and ".".
/// For example "fruits.bananas"
/// names are considered the same if they completely match or `name_without_dot` matches the part of the name to the point
static auto getNameRange(const ColumnsDescription::Container & columns, const String & name_without_dot)
{
String name_with_dot = name_without_dot + ".";
auto begin = columns.begin();
for (; begin != columns.end(); ++begin)
{
if (begin->name == name_without_dot)
return std::make_pair(begin, std::next(begin));
if (startsWith(begin->name, name_with_dot))
break;
}
if (begin == columns.end())
return std::make_pair(begin, begin);
auto end = std::next(begin);
for (; end != columns.end(); ++end)
{
if (!startsWith(end->name, name_with_dot))
break;
}
return std::make_pair(begin, end);
}
void ColumnsDescription::add(ColumnDescription column, const String & after_column)
{
if (has(column.name))
throw Exception("Cannot add column " + column.name + ": column with this name already exists",
ErrorCodes::ILLEGAL_COLUMN);
auto insert_it = columns.cend();
if (!after_column.empty())
{
auto range = getNameRange(columns, after_column);
if (range.first == range.second)
throw Exception("Wrong column name. Cannot find column " + after_column + " to insert after",
ErrorCodes::NO_SUCH_COLUMN_IN_TABLE);
insert_it = range.second;
}
columns.get<0>().insert(insert_it, std::move(column));
}
void ColumnsDescription::remove(const String & column_name)
{
auto range = getNameRange(columns, column_name);
if (range.first == range.second)
throw Exception("There is no column " + column_name + " in table.",
ErrorCodes::NO_SUCH_COLUMN_IN_TABLE);
for (auto list_it = range.first; list_it != range.second;)
list_it = columns.get<0>().erase(list_it);
}
void ColumnsDescription::flattenNested()
{
for (auto it = columns.begin(); it != columns.end();)
{
const auto * type_arr = typeid_cast<const DataTypeArray *>(it->type.get());
if (!type_arr)
{
++it;
continue;
}
const auto * type_tuple = typeid_cast<const DataTypeTuple *>(type_arr->getNestedType().get());
if (!type_tuple)
{
++it;
continue;
}
ColumnDescription column = std::move(*it);
it = columns.get<0>().erase(it);
const DataTypes & elements = type_tuple->getElements();
const Strings & names = type_tuple->getElementNames();
size_t tuple_size = elements.size();
for (size_t i = 0; i < tuple_size; ++i)
{
auto nested_column = column;
/// TODO: what to do with default expressions?
nested_column.name = Nested::concatenateName(column.name, names[i]);
nested_column.type = std::make_shared<DataTypeArray>(elements[i]);
columns.get<0>().insert(it, std::move(nested_column));
}
}
}
NamesAndTypesList ColumnsDescription::getOrdinary() const
{
NamesAndTypesList ret;
for (const auto & col : columns)
if (col.default_desc.kind == ColumnDefaultKind::Default)
ret.emplace_back(col.name, col.type);
return ret;
}
NamesAndTypesList ColumnsDescription::getMaterialized() const
{
NamesAndTypesList ret;
for (const auto & col : columns)
if (col.default_desc.kind == ColumnDefaultKind::Materialized)
ret.emplace_back(col.name, col.type);
return ret;
}
NamesAndTypesList ColumnsDescription::getAliases() const
{
NamesAndTypesList ret;
for (const auto & col : columns)
if (col.default_desc.kind == ColumnDefaultKind::Alias)
ret.emplace_back(col.name, col.type);
return ret;
}
NamesAndTypesList ColumnsDescription::getAll() const
{
NamesAndTypesList ret;
for (const auto & col : columns)
ret.emplace_back(col.name, col.type);
return ret;
}
bool ColumnsDescription::has(const String & column_name) const
{
return columns.get<1>().find(column_name) != columns.get<1>().end();
}
bool ColumnsDescription::hasNested(const String & column_name) const
{
auto range = getNameRange(columns, column_name);
return range.first != range.second && range.first->name.length() > column_name.length();
}
const ColumnDescription & ColumnsDescription::get(const String & column_name) const
{
auto it = columns.get<1>().find(column_name);
if (it == columns.get<1>().end())
throw Exception("There is no column " + column_name + " in table.",
ErrorCodes::NO_SUCH_COLUMN_IN_TABLE);
return *it;
}
NamesAndTypesList ColumnsDescription::getAllPhysical() const
{
NamesAndTypesList ret;
for (const auto & col : columns)
if (col.default_desc.kind != ColumnDefaultKind::Alias)
ret.emplace_back(col.name, col.type);
return ret;
}
Names ColumnsDescription::getNamesOfPhysical() const
{
Names ret;
for (const auto & col : columns)
if (col.default_desc.kind != ColumnDefaultKind::Alias)
ret.emplace_back(col.name);
return ret;
}
NameAndTypePair ColumnsDescription::getPhysical(const String & column_name) const
{
auto it = columns.get<1>().find(column_name);
if (it == columns.get<1>().end() || it->default_desc.kind == ColumnDefaultKind::Alias)
throw Exception("There is no physical column " + column_name + " in table.", ErrorCodes::NO_SUCH_COLUMN_IN_TABLE);
return NameAndTypePair(it->name, it->type);
}
bool ColumnsDescription::hasPhysical(const String & column_name) const
{
auto it = columns.get<1>().find(column_name);
return it != columns.get<1>().end() && it->default_desc.kind != ColumnDefaultKind::Alias;
}
ColumnDefaults ColumnsDescription::getDefaults() const
{
ColumnDefaults ret;
for (const auto & column : columns)
if (column.default_desc.expression)
ret.emplace(column.name, column.default_desc);
return ret;
}
bool ColumnsDescription::hasDefault(const String & column_name) const
{
auto it = columns.get<1>().find(column_name);
return it != columns.get<1>().end() && it->default_desc.expression;
}
std::optional<ColumnDefault> ColumnsDescription::getDefault(const String & column_name) const
{
auto it = columns.get<1>().find(column_name);
if (it != columns.get<1>().end() && it->default_desc.expression)
return it->default_desc;
return {};
}
CompressionCodecPtr ColumnsDescription::getCodecOrDefault(const String & column_name, CompressionCodecPtr default_codec) const
{
const auto it = columns.get<1>().find(column_name);
if (it == columns.get<1>().end() || !it->codec)
return default_codec;
return it->codec;
}
CompressionCodecPtr ColumnsDescription::getCodecOrDefault(const String & column_name) const
{
return getCodecOrDefault(column_name, CompressionCodecFactory::instance().getDefaultCodec());
}
ColumnsDescription::ColumnTTLs ColumnsDescription::getColumnTTLs() const
{
ColumnTTLs ret;
for (const auto & column : columns)
if (column.ttl)
ret.emplace(column.name, column.ttl);
return ret;
}
String ColumnsDescription::toString() const
{
WriteBufferFromOwnString buf;
writeCString("columns format version: 1\n", buf);
DB::writeText(columns.size(), buf);
writeCString(" columns:\n", buf);
for (const ColumnDescription & column : columns)
column.writeText(buf);
return buf.str();
}
ColumnsDescription ColumnsDescription::parse(const String & str)
{
ReadBufferFromString buf{str};
assertString("columns format version: 1\n", buf);
size_t count{};
readText(count, buf);
assertString(" columns:\n", buf);
ColumnsDescription result;
for (size_t i = 0; i < count; ++i)
{
ColumnDescription column;
column.readText(buf);
buf.ignore(1); /// ignore new line
result.add(std::move(column));
}
assertEOF(buf);
return result;
}
}