Package uk.ac.starlink.table.storage
Class SidewaysRowStore
- java.lang.Object
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- uk.ac.starlink.table.storage.SidewaysRowStore
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public class SidewaysRowStore extends java.lang.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
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Constructor Summary
Constructors Constructor Description SidewaysRowStore()
Constructs a new row store with an automatically chosen (and guaranteed unique) base pathname for scrach files.SidewaysRowStore(java.io.File file)
Constructs a new row store with a given base path name to use for temporary files.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
acceptMetadata(StarTable meta)
Takes delivery of a row-less StarTable object which defines the metadata of the table to be transmitted.void
acceptRow(java.lang.Object[] row)
Takes delivery of one row of data.void
endRows()
Signals that there are no more rows to be transmitted.protected void
finalize()
StarTable
getStarTable()
Obtains a StarTable which contains the data and metadata that have been written into this sink.
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Constructor Detail
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SidewaysRowStore
public SidewaysRowStore(java.io.File file) throws java.io.IOException
Constructs a new row store with a given base path name to use for temporary files.- Parameters:
file
- base scratch file name- Throws:
java.io.IOException
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SidewaysRowStore
public SidewaysRowStore() throws java.io.IOException
Constructs a new row store with an automatically chosen (and guaranteed unique) base pathname for scrach files.- Throws:
java.io.IOException
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Method Detail
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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 interfaceTableSink
- Parameters:
meta
- table metadata object- Throws:
TableFormatException
- if this sink cannot accept table rows matching the given metadata
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acceptRow
public void acceptRow(java.lang.Object[] row) throws java.io.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.
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endRows
public void endRows() throws java.io.IOException
Description copied from interface:TableSink
Signals that there are no more rows to be transmitted.
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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 toTableSink.endRows()
; failing to observe this sequence may earn you an IllegalStateException- Specified by:
getStarTable
in interfaceRowStore
- Returns:
- a random-access StarTable containing the written rows
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finalize
protected void finalize() throws java.lang.Throwable
- Overrides:
finalize
in classjava.lang.Object
- Throws:
java.lang.Throwable
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