#pragma once #include #if USE_HDFS #include namespace DB { class Context; /** * hdfsCluster(cluster, URI, format, structure, compression_method) * A table function, which allows to process many files from HDFS on a specific cluster * On initiator it creates a connection to _all_ nodes in cluster, discloses asterics * in HDFS file path and dispatch each file dynamically. * On worker node it asks initiator about next task to process, processes it. * This is repeated until the tasks are finished. */ class TableFunctionHDFSCluster : public ITableFunction { public: static constexpr auto name = "hdfsCluster"; std::string getName() const override { return name; } bool hasStaticStructure() const override { return true; } protected: StoragePtr executeImpl( const ASTPtr & ast_function, ContextPtr context, const std::string & table_name, ColumnsDescription cached_columns) const override; const char * getStorageTypeName() const override { return "HDFSCluster"; } ColumnsDescription getActualTableStructure(ContextPtr) const override; void parseArguments(const ASTPtr &, ContextPtr) override; String cluster_name; String uri; String format; String structure; String compression_method = "auto"; }; } #endif