Class SidewaysRowStore

java.lang.Object
uk.ac.starlink.table.storage.SidewaysRowStore
All Implemented Interfaces:
RowStore, TableSink

public class SidewaysRowStore extends Object implements RowStore
RowStore implementation which stores data cell data in a column-oriented fashion, so that members of the same column, rather than of the same row, are stored contiguously on disk.
Since:
21 Jun 2006
Author:
Mark Taylor
  • Constructor Summary

    Constructors
    Constructor
    Description
    Constructs a new row store with an automatically chosen (and guaranteed unique) base pathname for scrach files.
    Constructs a new row store with a given base path name to use for temporary files.
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    Takes delivery of a row-less StarTable object which defines the metadata of the table to be transmitted.
    void
    Takes delivery of one row of data.
    void
    Signals that there are no more rows to be transmitted.
    Obtains a StarTable which contains the data and metadata that have been written into this sink.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Constructor Details

    • SidewaysRowStore

      public SidewaysRowStore(File file) throws IOException
      Constructs a new row store with a given base path name to use for temporary files.
      Parameters:
      file - base scratch file name
      Throws:
      IOException
    • SidewaysRowStore

      public SidewaysRowStore() throws IOException
      Constructs a new row store with an automatically chosen (and guaranteed unique) base pathname for scrach files.
      Throws:
      IOException
  • Method Details

    • acceptMetadata

      public void acceptMetadata(StarTable meta) throws TableFormatException
      Description copied from interface: TableSink
      Takes delivery of a row-less StarTable object which defines the metadata of the table to be transmitted. If the number of rows that will be transmitted via subsequent calls to acceptRow is known, this value should be made available as the row count of meta (StarTable.getRowCount()); if it is not known, the row count should be -1. However, this object should not attempt to read any of meta's cell data.

      The data to be transmitted in subsequent calls of acceptRow must match the metadata transmitted in this call in the same way that rows of a StarTable must match its own metadata (number and content clases of columns etc). If this sink cannot dispose of a table corresponding to meta then it may throw a TableFormatException - this may be the case if for instance meta has columns with types that this sink can't deal with.

      Specified by:
      acceptMetadata in interface TableSink
      Parameters:
      meta - table metadata object
      Throws:
      TableFormatException - if this sink cannot accept table rows matching the given metadata
    • acceptRow

      public void acceptRow(Object[] row) throws IOException
      Description copied from interface: TableSink
      Takes delivery of one row of data. row is an array of objects comprising the contents of one row of the table being transmitted. The number and classes of the elements of row are described by the metadata object previously accepted.
      Specified by:
      acceptRow in interface TableSink
      Parameters:
      row - table data row
      Throws:
      IOException
    • endRows

      public void endRows() throws IOException
      Description copied from interface: TableSink
      Signals that there are no more rows to be transmitted.
      Specified by:
      endRows in interface TableSink
      Throws:
      IOException
    • getStarTable

      public StarTable getStarTable()
      Description copied from interface: RowStore
      Obtains a StarTable which contains the data and metadata that have been written into this sink. In general it is only legal to call this method following a call to TableSink.endRows(); failing to observe this sequence may earn you an IllegalStateException
      Specified by:
      getStarTable in interface RowStore
      Returns:
      a random-access StarTable containing the written rows