ClickHouse/dbms/include/DB/Storages/StorageFile.h
2016-11-14 02:57:18 +03:00

115 lines
2.7 KiB
C++

#pragma once
#include <DB/Storages/IStorage.h>
#include <Poco/File.h>
#include <Poco/Path.h>
#include <Poco/RWLock.h>
#include <common/logger_useful.h>
namespace DB
{
class StorageFileBlockInputStream;
class StorageFileBlockOutputStream;
class StorageFile : public IStorage
{
public:
/** there are three options (ordered by priority):
- use specified file descriptor if (fd >= 0)
- use specified table_path if it isn't empty
- create own tabale inside data/db/table/
*/
StorageFile(
const std::string & table_path_,
int table_fd_,
const std::string & db_dir_path,
const std::string & table_name_,
const std::string & format_name_,
const NamesAndTypesListPtr & columns_,
const NamesAndTypesList & materialized_columns_,
const NamesAndTypesList & alias_columns_,
const ColumnDefaults & column_defaults_,
Context & context_);
static StoragePtr create(
const std::string & table_path,
int table_fd,
const std::string & db_dir_path,
const std::string & table_name,
const std::string & format_name,
const NamesAndTypesListPtr & columns,
const NamesAndTypesList & materialized_columns_,
const NamesAndTypesList & alias_columns_,
const ColumnDefaults & column_defaults_,
Context & context)
{
return std::make_shared<StorageFile>(
table_path, table_fd,
db_dir_path, table_name, format_name, columns,
materialized_columns_, alias_columns_, column_defaults_,
context);
}
std::string getName() const override
{
return "File";
}
std::string getTableName() const override
{
return table_name;
}
const NamesAndTypesList & getColumnsListImpl() const override
{
return *columns;
}
BlockInputStreams read(
const Names & column_names,
ASTPtr query,
const Context & context,
const Settings & settings,
QueryProcessingStage::Enum & processed_stage,
size_t max_block_size = DEFAULT_BLOCK_SIZE,
unsigned threads = 1) override;
BlockOutputStreamPtr write(
ASTPtr query,
const Settings & settings) override;
void drop() override;
void rename(const String & new_path_to_db, const String & new_database_name, const String & new_table_name) override;
protected:
friend class StorageFileBlockInputStream;
friend class StorageFileBlockOutputStream;
private:
std::string table_name;
std::string format_name;
NamesAndTypesListPtr columns;
Context & context_global;
std::string path;
int table_fd = -1;
bool is_db_table = true; /// Table is stored in real database, not user's file
bool use_table_fd = false; /// Use table_fd insted of path
std::atomic<bool> table_fd_was_used{false}; /// To detect repeating reads from stdin
off_t table_fd_init_offset = -1; /// Initial position of fd, used for repeating reads
mutable Poco::RWLock rwlock;
Logger * log = &Logger::get("StorageFile");
};
}