ClickHouse/src/Dictionaries/FileDictionarySource.h
Артем Стрельцов 741775a12f fixed some remarks from review
2020-04-17 22:54:53 +03:00

69 lines
2.0 KiB
C++

#pragma once
#include <Poco/Timestamp.h>
#include "IDictionarySource.h"
#include <Core/Block.h>
#include <Interpreters/Context.h>
namespace DB
{
namespace ErrorCodes
{
extern const int NOT_IMPLEMENTED;
}
/// Allows loading dictionaries from a file with given format, does not support "random access"
class FileDictionarySource final : public IDictionarySource
{
public:
FileDictionarySource(const std::string & filepath_, const std::string & format_,
Block & sample_block_, const Context & context_, bool check_config);
FileDictionarySource(const FileDictionarySource & other);
BlockInputStreamPtr loadAll() override;
BlockInputStreamPtr loadUpdatedAll() override
{
throw Exception{"Method loadUpdatedAll is unsupported for FileDictionarySource", ErrorCodes::NOT_IMPLEMENTED};
}
BlockInputStreamPtr loadIds(const std::vector<UInt64> & /*ids*/) override
{
throw Exception{"Method loadIds is unsupported for FileDictionarySource", ErrorCodes::NOT_IMPLEMENTED};
}
BlockInputStreamPtr loadKeys(const Columns & /*key_columns*/, const std::vector<size_t> & /*requested_rows*/) override
{
throw Exception{"Method loadKeys is unsupported for FileDictionarySource", ErrorCodes::NOT_IMPLEMENTED};
}
bool isModified() const override
{
// We can't count on that the mtime increases or that it has
// a particular relation to system time, so just check for strict
// equality.
return getLastModification() != last_modification;
}
bool supportsSelectiveLoad() const override { return false; }
///Not supported for FileDictionarySource
bool hasUpdateField() const override { return false; }
DictionarySourcePtr clone() const override { return std::make_unique<FileDictionarySource>(*this); }
std::string toString() const override;
private:
Poco::Timestamp getLastModification() const;
const std::string filepath;
const std::string format;
Block sample_block;
const Context context;
Poco::Timestamp last_modification;
};
}