ClickHouse/src/Storages/StorageFile.h
2020-08-03 16:54:14 +03:00

98 lines
2.7 KiB
C++

#pragma once
#include <Storages/IStorage.h>
#include <Poco/File.h>
#include <Poco/Path.h>
#include <common/logger_useful.h>
#include <atomic>
#include <shared_mutex>
#include <ext/shared_ptr_helper.h>
namespace DB
{
class StorageFileBlockInputStream;
class StorageFileBlockOutputStream;
class StorageFile final : public ext::shared_ptr_helper<StorageFile>, public IStorage
{
friend struct ext::shared_ptr_helper<StorageFile>;
public:
std::string getName() const override { return "File"; }
Pipe read(
const Names & column_names,
const StorageMetadataPtr & /*metadata_snapshot*/,
const SelectQueryInfo & query_info,
const Context & context,
QueryProcessingStage::Enum processed_stage,
size_t max_block_size,
unsigned num_streams) override;
BlockOutputStreamPtr write(
const ASTPtr & query,
const StorageMetadataPtr & /*metadata_snapshot*/,
const Context & context) override;
void truncate(
const ASTPtr & /*query*/,
const StorageMetadataPtr & /* metadata_snapshot */,
const Context & /* context */,
TableExclusiveLockHolder &) override;
void rename(const String & new_path_to_table_data, const StorageID & new_table_id) override;
Strings getDataPaths() const override;
struct CommonArguments
{
const StorageID & table_id;
const std::string & format_name;
const std::string & compression_method;
const ColumnsDescription & columns;
const ConstraintsDescription & constraints;
const Context & context;
};
NamesAndTypesList getVirtuals() const override;
protected:
friend class StorageFileSource;
friend class StorageFileBlockOutputStream;
/// From file descriptor
StorageFile(int table_fd_, CommonArguments args);
/// From user's file
StorageFile(const std::string & table_path_, const std::string & user_files_path, CommonArguments args);
/// From table in database
StorageFile(const std::string & relative_table_dir_path, CommonArguments args);
private:
explicit StorageFile(CommonArguments args);
std::string format_name;
int table_fd = -1;
String compression_method;
std::string base_path;
std::vector<std::string> paths;
bool is_db_table = true; /// Table is stored in real database, not user's file
bool use_table_fd = false; /// Use table_fd instead 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 std::shared_mutex rwlock;
Poco::Logger * log = &Poco::Logger::get("StorageFile");
};
}