Class ConcatStarTable
- All Implemented Interfaces:
Closeable
,AutoCloseable
,StarTable
- Since:
- 29 Mar 2004
- Author:
- Mark Taylor
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Field Summary
Fields inherited from class uk.ac.starlink.table.WrapperStarTable
baseTable
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Constructor Summary
ConstructorsConstructorDescriptionConcatStarTable
(StarTable meta, Iterator<StarTable> tableIt) Constructs a concatenated table from a metadata table and an iterator over data-bearing tables.ConcatStarTable
(StarTable meta, StarTable[] tables) Constructs a concatenated table from a metadata table and an array of data-bearing tables. -
Method Summary
Modifier and TypeMethodDescriptionstatic ColumnInfo[]
extendColumnTypes
(ColumnInfo[] colInfos, StarTable[] tables) Assembles column metadata objects which are compatible between multiple tables.getCell
(long irow, int icol) Returns the contents of a given table cell.Object[]
getRow
(long irow) Returns the contents of a given table row.Returns an object which can provide random access to this table's data, if random access is implemented.long
Returns the number of rows in this table, if known.Returns an object which can iterate over all the rows in the table sequentially.Returns an object which can iterate over all the rows in the table, but which may also be requested to split recursively for potentially parallel processing.boolean
isRandom()
Indicates whether random access is provided by this table.Methods inherited from class uk.ac.starlink.table.WrapperStarTable
checkedLongToInt, close, getBaseTable, getColumnAuxDataInfos, getColumnCount, getColumnInfo, getName, getParameterByName, getParameters, getURL, setName, setParameter, setURL, toString
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Constructor Details
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ConcatStarTable
Constructs a concatenated table from a metadata table and an iterator over data-bearing tables. If any of the tables supplied by the iterator are incompatible with the metadata inmeta
a warning message is issued through the logging system and its rows are ignored.- Parameters:
meta
- table supplying column and table metadata for this one; its row count is ignored and its data is never readtableIt
- iterator over constituentStarTable
s which taken in sequence supply the row data for this one
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ConcatStarTable
Constructs a concatenated table from a metadata table and an array of data-bearing tables. If any oftables
are incompatible with the metadata inmeta
an IOException is thrown.- Parameters:
meta
- table supplying column and table metadata for this one; its row count is ignored and its data is never readtables
- array of tables which taken in sequence supply the row data for this one- Throws:
IOException
- if any oftables
are not compatible withmeta
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Method Details
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getRowCount
public long getRowCount()Description copied from interface:StarTable
Returns the number of rows in this table, if known. If the number of rows cannot be (easily) determined, a value of -1 will be returned.- Specified by:
getRowCount
in interfaceStarTable
- Overrides:
getRowCount
in classWrapperStarTable
- Returns:
- the number of rows, or -1
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getCell
Description copied from interface:StarTable
Returns the contents of a given table cell. The class of the returned object should be the same as, or a subclass of, the class returned bygetColumnInfo(icol).getContentClass()
.This method is safe for concurrent use from multiple threads, but in general it is recommended to use a
RowAccess
instead.- Specified by:
getCell
in interfaceStarTable
- Overrides:
getCell
in classWrapperStarTable
- Parameters:
irow
- the index of the cell's rowicol
- the index of the cell's column- Returns:
- the contents of this cell
- Throws:
IOException
- if there is an error reading the data
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getRow
Description copied from interface:StarTable
Returns the contents of a given table row. The returned value is equivalent to an array formed of all the objects returned bygetCell(irow,icol)
for all the columnsicol
in sequence.This method is safe for concurrent use from multiple threads, but in general it is recommended to use a
RowAccess
instead.- Specified by:
getRow
in interfaceStarTable
- Overrides:
getRow
in classWrapperStarTable
- Parameters:
irow
- the index of the row to retrieve- Returns:
- an array of the objects in each cell in row
irow
- Throws:
IOException
- if there is an error reading the data
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isRandom
public boolean isRandom()Description copied from interface:StarTable
Indicates whether random access is provided by this table. Only if the result istrue
may theStarTable.getRowAccess()
,StarTable.getRow(long)
andStarTable.getCell(long, int)
methods be used.- Specified by:
isRandom
in interfaceStarTable
- Overrides:
isRandom
in classWrapperStarTable
- Returns:
true
if table random access methods are available
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getRowSequence
Description copied from interface:StarTable
Returns an object which can iterate over all the rows in the table sequentially. Each such returned object is safe for use within a single thread, but not in general from multiple threads concurrently.- Specified by:
getRowSequence
in interfaceStarTable
- Overrides:
getRowSequence
in classWrapperStarTable
- Returns:
- new RowSequence
- Throws:
IOException
- if there is an error providing access
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getRowSplittable
Description copied from interface:StarTable
Returns an object which can iterate over all the rows in the table, but which may also be requested to split recursively for potentially parallel processing.The return value must be non-null, and may provide splitting arrangements specially appropriate for the implementation. If this table 'wraps' an upstream table, it is usually best to base the implementation on calls to the the upstream
getRowSplittable
method, so that upstream policy about how to divide up the table is respected. However, implementations without special requirements may returnTables.getDefaultRowSplittable
(this)
.- Specified by:
getRowSplittable
in interfaceStarTable
- Overrides:
getRowSplittable
in classWrapperStarTable
- Returns:
- new RowSplittable
- Throws:
IOException
- See Also:
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getRowAccess
Description copied from interface:StarTable
Returns an object which can provide random access to this table's data, if random access is implemented. Each such returned object is safe for use within a single thread, but not in general from multiple threads concurrently.- Specified by:
getRowAccess
in interfaceStarTable
- Overrides:
getRowAccess
in classWrapperStarTable
- Returns:
- new RowAccess
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extendColumnTypes
public static ColumnInfo[] extendColumnTypes(ColumnInfo[] colInfos, StarTable[] tables) throws IOException Assembles column metadata objects which are compatible between multiple tables. Nullability, array shape and element size are set to values which can accommodate all of the input tables. If column count or column data types are inconsistent, an IOException is thrown.This utility method is not used by ConcatStarTable instances, but it may be useful when preparing metadata tables for use with the constructor.
- Parameters:
colInfos
- input column metadata objectstables
- list of tables with which columns must be compatible- Returns:
- new array of new column metadata objects, based on input list
- Throws:
IOException
- if compatibility cannot be achieved
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