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119 lines
2.9 KiB
C++
119 lines
2.9 KiB
C++
#pragma once
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#include <map>
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#include <list>
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#include <string>
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#include <set>
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#include <Poco/SharedPtr.h>
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#include <DB/DataTypes/IDataType.h>
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#include <DB/DataTypes/DataTypeFactory.h>
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namespace DB
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{
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using Poco::SharedPtr;
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struct NameAndTypePair
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{
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String name;
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DataTypePtr type;
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NameAndTypePair() {}
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NameAndTypePair(const String & name_, const DataTypePtr & type_) : name(name_), type(type_) {}
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bool operator<(const NameAndTypePair & rhs) const
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{
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return std::make_pair(std::cref(name), type->getName()) < std::make_pair(std::cref(rhs.name), rhs.type->getName());
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}
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bool operator==(const NameAndTypePair & rhs) const
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{
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return name == rhs.name && type->getName() == rhs.type->getName();
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}
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};
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typedef std::vector<NameAndTypePair> NamesAndTypes;
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class NamesAndTypesList : public std::list<NameAndTypePair>
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{
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public:
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using std::list<NameAndTypePair>::list;
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void readText(ReadBuffer & buf, const DataTypeFactory & data_type_factory)
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{
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DB::assertString("columns format version: 1\n", buf);
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size_t count;
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DB::readText(count, buf);
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DB::assertString(" columns:\n", buf);
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resize(count);
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for (NameAndTypePair & it : *this)
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{
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DB::readBackQuotedString(it.name, buf);
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DB::assertString(" ", buf);
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String type_name;
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DB::readString(type_name, buf);
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it.type = data_type_factory.get(type_name);
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DB::assertString("\n", buf);
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}
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}
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void writeText(WriteBuffer & buf)
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{
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DB::writeString("columns format version: 1\n", buf);
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DB::writeText(size(), buf);
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DB::writeString(" columns:\n", buf);
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for (const auto & it : *this)
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{
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DB::writeBackQuotedString(it.name, buf);
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DB::writeChar(' ', buf);
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DB::writeString(it.type->getName(), buf);
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DB::writeChar('\n', buf);
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}
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}
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String toString() const
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{
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String s;
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{
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WriteBufferFromString out(s);
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writeText(out);
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}
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return s;
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}
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static NamesAndTypesList parse(const String & s)
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{
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ReadBufferFromString in(s);
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NamesAndTypesList res;
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res.readText(in);
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assertEOF(in);
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return res;
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}
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/// Все элементы rhs должны быть различны.
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bool isSubsetOf(const NamesAndTypesList & rhs) const
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{
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NamesAndTypes vector(rhs.begin(), rhs.end());
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vector.insert(vector.end(), begin(), end());
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std::sort(vector.begin(), vector.end());
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return std::unique(vector.begin(), vector.end()) == vector.begin() + rhs.size();
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}
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/// Расстояние Хемминга между множествами
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/// (иными словами, добавленные и удаленные столбцы считаются один раз; столбцы, изменившие тип, - дважды).
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size_t sizeOfDifference(const NamesAndTypesList & rhs) const
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{
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NamesAndTypes vector(rhs.begin(), rhs.end());
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vector.insert(vector.end(), begin(), end());
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std::sort(vector.begin(), vector.end());
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return (std::unique(vector.begin(), vector.end()) - vector.begin()) * 2 - size() - rhs.size();
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}
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};
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typedef SharedPtr<NamesAndTypesList> NamesAndTypesListPtr;
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}
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