ClickHouse/dbms/include/DB/Storages/StorageTinyLog.h
2013-05-04 04:05:15 +00:00

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#pragma once
#include <Poco/File.h>
#include <DB/Core/NamesAndTypes.h>
#include <DB/IO/ReadBufferFromFile.h>
#include <DB/IO/WriteBufferFromFile.h>
#include <DB/IO/CompressedReadBuffer.h>
#include <DB/IO/CompressedWriteBuffer.h>
#include <DB/Storages/IStorage.h>
#include <DB/DataStreams/IProfilingBlockInputStream.h>
namespace DB
{
class StorageTinyLog;
class TinyLogBlockInputStream : public IProfilingBlockInputStream
{
public:
TinyLogBlockInputStream(size_t block_size_, const Names & column_names_, StoragePtr owned_storage);
String getName() const { return "TinyLogBlockInputStream"; }
String getID() const
{
std::stringstream res;
res << "TinyLog(" << owned_storage->getTableName() << ", " << &*owned_storage;
for (size_t i = 0; i < column_names.size(); ++i)
res << ", " << column_names[i];
res << ")";
return res.str();
}
protected:
Block readImpl();
private:
size_t block_size;
Names column_names;
StorageTinyLog & storage;
bool finished;
struct Stream
{
Stream(const std::string & data_path)
: plain(data_path, std::min(static_cast<size_t>(DBMS_DEFAULT_BUFFER_SIZE), Poco::File(data_path).getSize())),
compressed(plain)
{
}
ReadBufferFromFile plain;
CompressedReadBuffer compressed;
};
typedef std::map<std::string, SharedPtr<Stream> > FileStreams;
FileStreams streams;
void addStream(const String & name, const IDataType & type, size_t level = 0);
void readData(const String & name, const IDataType & type, IColumn & column, size_t limit, size_t level = 0);
};
class TinyLogBlockOutputStream : public IBlockOutputStream
{
public:
TinyLogBlockOutputStream(StoragePtr owned_storage);
void write(const Block & block);
private:
StorageTinyLog & storage;
struct Stream
{
Stream(const std::string & data_path) :
plain(data_path, DBMS_DEFAULT_BUFFER_SIZE, O_APPEND | O_CREAT | O_WRONLY),
compressed(plain)
{
}
WriteBufferFromFile plain;
CompressedWriteBuffer compressed;
};
typedef std::map<std::string, SharedPtr<Stream> > FileStreams;
FileStreams streams;
void addStream(const String & name, const IDataType & type, size_t level = 0);
void writeData(const String & name, const IDataType & type, const IColumn & column, size_t level = 0);
};
/** Реализует хранилище, подходящее для маленьких кусочков лога.
* Отличается от StorageLog отсутствием файлов с засечками.
*/
class StorageTinyLog : public IStorage
{
friend class TinyLogBlockInputStream;
friend class TinyLogBlockOutputStream;
public:
/** Подцепить таблицу с соответствующим именем, по соответствующему пути (с / на конце),
* (корректность имён и путей не проверяется)
* состоящую из указанных столбцов.
* Если не указано attach - создать директорию, если её нет.
*/
static StoragePtr create(const std::string & path_, const std::string & name_, NamesAndTypesListPtr columns_, bool attach);
std::string getName() const { return "TinyLog"; }
std::string getTableName() const { return name; }
const NamesAndTypesList & getColumnsList() const { return *columns; }
BlockInputStreams read(
const Names & column_names,
ASTPtr query,
const Settings & settings,
QueryProcessingStage::Enum & processed_stage,
size_t max_block_size = DEFAULT_BLOCK_SIZE,
unsigned threads = 1);
BlockOutputStreamPtr write(
ASTPtr query);
void dropImpl();
void rename(const String & new_path_to_db, const String & new_name);
private:
String path;
String name;
NamesAndTypesListPtr columns;
/// Данные столбца
struct ColumnData
{
Poco::File data_file;
};
typedef std::map<String, ColumnData> Files_t;
Files_t files;
StorageTinyLog(const std::string & path_, const std::string & name_, NamesAndTypesListPtr columns_, bool attach);
void addFile(const String & column_name, const IDataType & type, size_t level = 0);
};
}