org.apache.druid.catalog.model.table

Interface InputFormatDefn

All Known Implementing Classes:

InputFormats.BaseFormatDefn, InputFormats.CsvFormatDefn, InputFormats.DelimitedFormatDefn, InputFormats.FlatTextFormatDefn, InputFormats.JsonFormatDefn

public interface InputFormatDefn

Metadata about a Druid InputFormat. Provides the logic to convert from a table spec or SQL function arguments to a specific form of InputFormat. There is one instance of this interface for each supported InputFormat.

Method Summary

Modifier and Type	Method and Description
InputFormat	convertFromArgs(Map<String,Object> args, List<ColumnSpec> columns, com.fasterxml.jackson.databind.ObjectMapper jsonMapper) Create an input format instance from the values provided as arguments that correspond to the defined parameters.
InputFormat	convertFromTable(ResolvedExternalTable table) Create an input format from a resolved catalog table spec.
List<TableFunction.ParameterDefn>	parameters() Obtain the parameters used to fully define an input format in a SQL function that defines an external table from scratch.
String	typeValue()
void	validate(ResolvedExternalTable table) Given a resolved table that has the serialized JSON converted to a Java map, validate the values of that map, typically by converting that map the target input format object (after adjustments and filling in dummy columns.) THe goal is to validate the information the user has provided in the table spec.

Method Detail

typeValue

String typeValue()

Returns:

the string used to identify the input format type in the serialized JSON for the input format. This is also the value used in the format property for SQL functions.

validate

void validate(ResolvedExternalTable table)

Given a resolved table that has the serialized JSON converted to a Java map, validate the values of that map, typically by converting that map the target input format object (after adjustments and filling in dummy columns.) THe goal is to validate the information the user has provided in the table spec. The final format information is validated elsewhere.

parameters

List<TableFunction.ParameterDefn> parameters()

Obtain the parameters used to fully define an input format in a SQL function that defines an external table from scratch. Note that the final list of table function arguments combines parameters from all the various input sources. It is legal for multiple formats to define the same parameter, as long as both definitions are of the same type.

Returns:

convertFromArgs

InputFormat convertFromArgs(Map<String,Object> args,
                            List<ColumnSpec> columns,
                            com.fasterxml.jackson.databind.ObjectMapper jsonMapper)

Create an input format instance from the values provided as arguments that correspond to the defined parameters. The map provided is guaranteed to have a value for each parameter defined as non-optional, and those values will be of the type defined in the parameter. The map will also contain values for the input source: the format should ignore values that don't correspond to parameters it defined.

Parameters:

args - the actual arguments for the defined parameters

columns - the columns provided in SQL, typically via the `EXTEND` clause, but perhaps from an the table spec, if the function is for a partial table

jsonMapper - the mapper to use to perform conversions

Returns:

an input format as defined by the arguments

Throws:

IAE - if the arguments are not valid

convertFromTable

InputFormat convertFromTable(ResolvedExternalTable table)

Create an input format from a resolved catalog table spec. The format is given by the Java map within the given object.

Parameters:

table - resolved form of a table spec, with the format JSON parsed into a JSON map

Returns:

an input format as defined by the table spec

Throws:

IAE - if the spec is not valid