Module datarush.library
Package com.pervasive.datarush.operators.io

Interface DataFormat

All Known Implementing Classes:
ARFFDataFormat, AvroFormat, BinaryFormat, DelimitedTextFormat, FixedTextFormat, JSONFormat, LogDataFormat, MDFFormat, ORCFormat, ParquetFormat
public interface DataFormat
Describes the record format of external data, such as in a file. A DataFormat object provides the necessary information for reading and writing external data, converting it to and from records in a dataflow graph.

Many formats are predefined in the library; an implementation is only required if a new format needs to be defined. Normally, it is not necessary to work directly with formats. Instead, operators are provided which hide the DataFormat object and present a view more appropriate to the specific format. Examples of this technique are the ReadDelimitedText and WriteDelimitedText operators.

See Also:

  • Method Details

    • getType

      RecordTokenType getType()
      Gets the record type associated with the format. Records produced by the associated parser or consumed by the associated formatter will be of this type.

      For many formats, this may be derived from a schema object describing the format layout.

      Returns:
      the format's record type

    • getMetadata

      FileMetadata getMetadata()
      Gets the metadata associated with the format. Records produces by the associated parser or consumed by the associated formatter will use this metadata.
      Returns:
      the format's metadata

    • setMetadata

      void setMetadata(FileMetadata metadata)
      Sets the metadata associated with the format.

    • readMetadata

      FileMetadata readMetadata(FileClient fileClient, ByteSource source)
      Reads the metadata associated with the format.
      Parameters:
      fileClient - client used to read file
      source - location of the files

    • writeMetadata

      void writeMetadata(FileMetadata metadata, FileClient fileClient, ByteSink target)
      Writes the provided metadata associated with the format.
      Parameters:
      metadata - the metadata to write
      fileClient - client used to write file
      source - location of the files

    • createParser

      DataFormat.DataParser createParser(ParsingOptions options)
      Create a new parser for the format using the specified parsing options.
      Parameters:
      options - parsing options to use
      Returns:
      a new parser for reading external data

    • createWriter

      DataFormat.DataFormatter createWriter(FormattingOptions options)
      Create a new writer for the format using the specified formatting options.
      Parameters:
      options - formatting options to use
      Returns:
      a new formatter for writing external data

    • isSplittable

      boolean isSplittable()
      Indicates if the format supports parsing of subsections of a file.

      A format should only return true if it can, at least in some situations, support this sort of parsing. If a format requires reading the entire file, it must return false.

      If a format is not splittable, a file in the format cannot be parsed in parallel; however, individual files can still be parsed independently in parallel, as when reading the contents of a directory or using a file globbing pattern.

      Returns:
      true if the format supports parsing only a portion of the file, false otherwise