uk.ac.starlink.ttools.cone

Interface UploadMatcher

All Known Implementing Classes:

CdsUploadMatcher, TapUploadMatcher

public interface UploadMatcher

Defines a service that can perform sky position crossmatches by taking a sequence of cone-like positions for input and submitting them as a block to a remote execution matching service.

The details of the methods are specified so that input can be streamed and output can be stored, with a final result table re-using table data from a reference input table that may have columns other than those represented by the cone sequence. It is also amenable to chunking the queries and responses.

Since:

14 May 2014

Author:

Mark Taylor

Method Summary

Modifier and Type	Method and Description
ColumnPlan	getColumnPlan(ColumnInfo[] resultCols, ColumnInfo[] uploadCols) Returns an object that understands what columns are where in an output table generated from the raw result produced by this matcher.
boolean	streamRawResult(ConeQueryRowSequence coneSeq, TableSink rawResultSink, RowMapper<?> rowMapper, long maxrec) Scans a sequence of positional queries, uploads it to a remote service, and writes the returned values to a given sink.

Method Detail

streamRawResult

boolean streamRawResult(ConeQueryRowSequence coneSeq,
                        TableSink rawResultSink,
                        RowMapper<?> rowMapper,
                        long maxrec)
                 throws IOException

Scans a sequence of positional queries, uploads it to a remote service, and writes the returned values to a given sink.

Both the read and the write should ideally be streamed (read as uploaded and written as received) so that progress can be logged properly.

The result is written to the given rawResultSink (which will probably be a RowStore). To make sense of the table thus written, it is necessary to use the RowMapper supplied to this method and the ColumnPlan available from this object. The RowMapper associates result rows with queries from the input row sequence, and the ColumnPlan knows where the special and other columns are in the result table.

Parameters:

coneSeq - sequence of cone-like positional queries

rawResultSink - destination for result rows obtained from the target matcher service

rowMapper - used to label rows; queries are labelled with the value returned from the getIndex method of coneSeq

maxrec - user-supplied limit on the maximum number of output rows, though the service may truncate the result; if <0, no limit is requested

Returns:

true iff the result was truncated due to overflow

Throws:

IOException

getColumnPlan

ColumnPlan getColumnPlan(ColumnInfo[] resultCols,
                         ColumnInfo[] uploadCols)

Returns an object that understands what columns are where in an output table generated from the raw result produced by this matcher.

Parameters:

resultCols - columns in the raw result table written by this object's streamRawResult method

uploadCols - columns from the table that will be joined to the raw result to get the output table

Returns:

column plan