Interface Definitions
April 27, 2025About 3 min
Interface Definitions
Schema
class TSDataType(IntEnum):
"""
Enumeration of data types currently supported by TsFile.
"""
BOOLEAN = 0
INT32 = 1
INT64 = 2
FLOAT = 3
DOUBLE = 4
TEXT = 5
STRING = 11
class ColumnCategory(IntEnum):
"""
Enumeration of column categories in TsFile.
TAG: Represents a tag column, used for metadata.
FIELD: Represents a field column, used for storing actual data values.
"""
TAG = 0
FIELD = 1
class ColumnSchema:
"""Defines schema for a table column (name, datatype, category)."""
column_name = None
data_type = None
category = None
def __init__(self, column_name: str, data_type: TSDataType,
category: ColumnCategory = ColumnCategory.FIELD)
class TableSchema:
"""Schema definition for a table structure."""
table_name = None
columns = None
def __init__(self, table_name: str, columns: List[ColumnSchema])
class ResultSetMetaData:
"""Metadata container for query result sets (columns, types, table name)."""
column_list = None
data_types = None
table_name = None
def __init__(self, column_list: List[str], data_types: List[TSDataType])Write interface
TsFileWriter
class TsFileTableWriter:
"""
Facilitates writing structured table data into a TsFile with a specified schema.
"""
"""
:param path: The path of tsfile, will create if it doesn't exist.
:param table_schema: describes the schema of the tables want to write.
:return: no return value.
"""
def __init__(self, path: str, table_schema: TableSchema)
"""
Write a tablet into table in tsfile.
:param tablet: stored batch data of a table.
:return: no return value.
"""
def write_table(self, tablet: Tablet)
"""
Close TsFileTableWriter and flush data automatically.
:return: no return value.
"""
def close(self)Tablet definition
You can use Tablet to insert data into TsFile in batches.
class Tablet(object)
"""
A pre-allocated columnar data container for batch data with type constraints.
Creates timestamp buffer and typed data columns, with value range validation ranges
for numeric types.
Initializes:
:param column_name_list: name list for data columns.
:param type_list: TSDataType values specifying allowed types per column.
:param max_row_num: Pre-allocated row capacity (default 1024)
:return: no return value.
"""
def __init__(self, column_name_list: list[str], type_list: list[TSDataType],
max_row_num: int = 1024)Read Interface
TsFileReader
class TsFileReader:
"""
Query table data from a TsFile.
"""
"""
Initialize a TsFile reader for the specified file path.
:param pathname: The path to the TsFile.
:return no return value.
"""
def __init__(self, pathname)
"""
Executes a time range query on the specified table and columns.
:param table_name: The name of the table to query.
:param column_names: A list of column names to retrieve.
:param start_time: The start time of the query range (default: minimum int64 value).
:param end_time: The end time of the query range (default: maximum int64 value).
:return: A query result set handler.
"""
def query_table(self, table_name : str, column_names : List[str],
start_time : int = np.iinfo(np.int64).min,
end_time: int = np.iinfo(np.int64).max) -> ResultSet
"""
Retrieves the schema of the specified table.
:param table_name: The name of the table.
:return: The schema of the specified table.
"""
def get_table_schema(self, table_name : str)-> TableSchema
"""
Retrieves the schemas of all tables in the TsFile.
:return: A dictionary mapping table names to their schemas.
"""
def get_all_table_schemas(self) ->dict[str, TableSchema]
"""
Closes the TsFile reader. If the reader has active result sets, they will be invalidated.
"""
def close(self)ResultSet
class ResultSet:
"""
Retrieves data from a query result set. When a query is executed, a query handler is returned.
If the reader is closed, the result set will become invalid.
"""
"""
Checks and moves to the next row in the query result set.
:return: True if the next row exists, False otherwise.
"""
def next(self) -> bool
"""
Retrieves the column information of the result set.
:return: A dictionary containing column names as keys and their data types as values.
"""
def get_result_column_info(self) -> dict[str, TsDataType]
"""
Fetches the next DataFrame from the query result set.
:param max_row_num: The maximum number of rows to retrieve. Default is 1024.
:return: A DataFrame containing data from the query result set.
"""
def read_next_data_frame(self, max_row_num : int = 1024) -> DataFrame
"""
Retrieves the value at the specified index from the query result set.
:param index: The index of the value to retrieve, 1 <= index <= column_num.
:return: The value at the specified index.
"""
def get_value_by_index(self, index : int)
"""
Retrieves the value for the specified column name from the query result set.
:param column_name: The name of the column to retrieve the value from.
:return: The value of the specified column.
"""
def get_value_by_name(self, column_name : str)
"""
Retrieves the metadata of the result set.
:return: The metadata of the result set as a ResultSetMetadata object.
"""
def get_metadata(self) -> ResultSetMetadata
"""
Checks whether the field at the specified index in the result set is null.
:param index: The index of the field to check. 1 <= index <= column_num.
:return: True if the field is null, False otherwise.
"""
def is_null_by_index(self, index : int)
"""
Checks whether the field with the specified column name in the result set is null.
:param name: The name of the column to check.
:return: True if the field is null, False otherwise.
"""
def is_null_by_name(self, name : str)
"""
Closes the result set and releases any associated resources.
"""
def close(self)