public class CacheRowPipe extends Object implements RowPipe
The current implementation simply delegates to a
OnceRowPipe
and caches the result before
returning it from waitForStarTable
. This is crude,
and means that the output rows don't start to come until all the input
rows have been written to the pipe (so there's not much point using a pipe).
A future implementation should get smarter with threads to improve this.
Constructor and Description |
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CacheRowPipe()
Constructor.
|
Modifier and Type | Method and 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(Object[] row)
Takes delivery of one row of data.
|
void |
endRows()
Signals that there are no more rows to be transmitted.
|
void |
setError(IOException err)
May be called by the writing stream to set an I/O error on the pipe.
|
StarTable |
waitForStarTable()
Returns a multiply-readable random access table.
|
public void acceptMetadata(StarTable meta) throws TableFormatException
TableSink
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.
acceptMetadata
in interface TableSink
meta
- table metadata objectTableFormatException
- if this sink cannot accept table rows
matching the given metadatapublic void acceptRow(Object[] row) throws IOException
TableSink
acceptRow
in interface TableSink
row
- table data rowIOException
public void endRows() throws IOException
TableSink
endRows
in interface TableSink
IOException
public void setError(IOException err)
RowPipe
e
as its cause from one of the read methods.
If an error has already been set by a previous call of this method,
this has no effect (only the first error is set).public StarTable waitForStarTable() throws IOException
waitForStarTable
in interface RowPipe
IOException
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