ReductionCollectionManager (Solr 7.2.1 API)

java.lang.Object
- org.apache.solr.analytics.function.ReductionCollectionManager

Direct Known Subclasses:

MergingReductionCollectionManager
```
public class ReductionCollectionManager
extends Object
```
The manager of reduction collection. Contains a group of ReductionDataCollectors which will be updated together.
The manager assumes a non-distributed request. MergingReductionCollectionManager is used for distributed requests.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class ReductionCollectionManager.ReductionDataCollection
Holds the collection of ReductionData that will be updated together.

Nested Classes
Modifier and Type	Class and Description
`static class`	`ReductionCollectionManager.ReductionDataCollection` Holds the collection of `ReductionData` that will be updated together.

Field Summary

Fields
Modifier and Type Field and Description

protected ReductionDataCollector<?>[] reductionDataCollectors

Fields
Modifier and Type	Field and Description
`protected ReductionDataCollector<?>[]`	`reductionDataCollectors`

Constructor Summary

Constructors
Constructor and Description
`ReductionCollectionManager()`
`ReductionCollectionManager(ReductionDataCollector<?>[] reductionDataCollectors, Iterable<AnalyticsField> fields)` Create a Manager to oversee the given `ReductionDataCollector`s.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addCollectTarget(ReductionCollectionManager.ReductionDataCollection target)` Add a `ReductionCollectionManager.ReductionDataCollection` to target while collecting the next document.
`void`	`addLastingCollectTarget(ReductionCollectionManager.ReductionDataCollection target)` Add a `ReductionCollectionManager.ReductionDataCollection` to target while collecting documents.
`void`	`apply()` Apply the values of the collected fields through the expressions' logic to the managed data collectors.
`void`	`clearLastingCollectTargets()` Clear lasting collection targets.
`void`	`collect(int doc)` Collect the values from the used `AnalyticsField`s.
`protected ReductionCollectionManager`	`createNewManager(ReductionDataCollector<?>[] reductionDataCollectors, Iterable<AnalyticsField> fields)` Create an `ReductionCollectionManager` to manage the given collectors and fields.
`void`	`doSetNextReader(LeafReaderContext context)` Set the context of the readers of the used `AnalyticsField`s.
`void`	`exportData()` Export the data from the set IO data collectors to the given shard output stream.
`Iterable<AnalyticsField>`	`getUsedFields()` Get the `AnalyticsField`s used in the managed expressions.
`ReductionCollectionManager`	`merge(Iterable<ReductionCollectionManager> reductionManagers)` Merge this collection manager with others.
`void`	`mergeData()` Merge the data from the given shard input stream into the set IO data collectors.
`boolean`	`needsCollection()` Return whether or not the manager needs collection done, which is false if no collectors are being managed and true if at least one is.
`ReductionCollectionManager.ReductionDataCollection`	`newDataCollection()` Construct a new data collection holding data for all managed data collectors.
`ReductionCollectionManager.ReductionDataCollection`	`newDataCollectionIO()` Create a new `ReductionCollectionManager.ReductionDataCollection` to merge to or export from.
`ReductionCollectionManager.ReductionDataCollection`	`newDataCollectionTarget()` Add a new `ReductionCollectionManager.ReductionDataCollection` to target while collecting the next document.
`void`	`prepareReductionDataIO(ReductionCollectionManager.ReductionDataCollection col)` Set the given data collection to be used for either merging or exporting
`void`	`setData(ReductionCollectionManager.ReductionDataCollection dataCollection)` Finalize the reductions with the collected data stored in the parameter.
`void`	`setShardInput(DataInput input)` Sets the stream of shard data to merge with.
`void`	`setShardOutput(DataOutput output)` Sets the stream to export shard data to.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - reductionDataCollectors
```
protected final ReductionDataCollector<?>[] reductionDataCollectors
```
- Constructor Detail
  - ReductionCollectionManager
```
public ReductionCollectionManager()
```
  - ReductionCollectionManager
```
public ReductionCollectionManager(ReductionDataCollector<?>[] reductionDataCollectors,
                                  Iterable<AnalyticsField> fields)
```
    Create a Manager to oversee the given ReductionDataCollectors.
    
    Parameters:
    
    reductionDataCollectors - array of collectors that are collecting over the same set of data
    
    fields - all fields used by the given collectors
- Method Detail
  - needsCollection
```
public boolean needsCollection()
```
    Return whether or not the manager needs collection done, which is false if no collectors are being managed and true if at least one is.
    
    Returns:
    
    true if at least one collector is being managed
  - merge
```
public ReductionCollectionManager merge(Iterable<ReductionCollectionManager> reductionManagers)
```
    Merge this collection manager with others.
    
    Parameters:
    
    reductionManagers - the collection managers to merge with
    
    Returns:
    
    a collection manager that manages the union of data collectors from this class and the given managers
  - createNewManager
```
protected ReductionCollectionManager createNewManager(ReductionDataCollector<?>[] reductionDataCollectors,
                                                      Iterable<AnalyticsField> fields)
```
    Create an ReductionCollectionManager to manage the given collectors and fields.
    
    Parameters:
    
    reductionDataCollectors - Reduction collectors
    
    fields - fields used by the reductions
    
    Returns:
    
    a collection manager
  - getUsedFields
```
public Iterable<AnalyticsField> getUsedFields()
```
    Get the AnalyticsFields used in the managed expressions.
    
    Returns:
    
    the fields used
  - doSetNextReader
```
public void doSetNextReader(LeafReaderContext context)
                     throws IOException
```
    Set the context of the readers of the used AnalyticsFields.
    
    Parameters:
    
    context - the reader context
    
    Throws:
    
    IOException - if an error occurs while setting the fields' context
  - collect
```
public void collect(int doc)
             throws IOException
```
    Collect the values from the used AnalyticsFields.
    
    Parameters:
    
    doc - the document to collect values for
    
    Throws:
    
    IOException - if an error occurs during field collection
  - addLastingCollectTarget
```
public void addLastingCollectTarget(ReductionCollectionManager.ReductionDataCollection target)
```
    Add a ReductionCollectionManager.ReductionDataCollection to target while collecting documents. This target is valid until the lasting targets are cleared.
    
    Parameters:
    
    target - data collection to add document data too
  - clearLastingCollectTargets
```
public void clearLastingCollectTargets()
```
    Clear lasting collection targets.
  - newDataCollectionTarget
```
public ReductionCollectionManager.ReductionDataCollection newDataCollectionTarget()
```
    Add a new ReductionCollectionManager.ReductionDataCollection to target while collecting the next document. This target is only valid for the next apply() call.
    
    Returns:
    
    the new data collection being targeted
  - addCollectTarget
```
public void addCollectTarget(ReductionCollectionManager.ReductionDataCollection target)
```
    Add a ReductionCollectionManager.ReductionDataCollection to target while collecting the next document. This target is only valid for the next apply() call.
    
    Parameters:
    
    target - data collection to add document data too
  - apply
```
public void apply()
```
    Apply the values of the collected fields through the expressions' logic to the managed data collectors. This is called after collect(int) has been called and the collection targets have been added.
  - setData
```
public void setData(ReductionCollectionManager.ReductionDataCollection dataCollection)
```
    Finalize the reductions with the collected data stored in the parameter. Once the data is finalized, the ReductionFunctions that use these ReductionDataCollectors act like regular AnalyticsValue classes that can be accessed through their get<value-type> methods.
    
    Parameters:
    
    dataCollection - the collection of reduction data to compute results for
  - newDataCollection
```
public ReductionCollectionManager.ReductionDataCollection newDataCollection()
```
    Construct a new data collection holding data for all managed data collectors.
    
    Returns:
    
    a new data collection
  - setShardInput
```
public void setShardInput(DataInput input)
```
    Sets the stream of shard data to merge with.
    
    Parameters:
    
    input - the stream of shard data
  - mergeData
```
public void mergeData()
               throws IOException
```
    Merge the data from the given shard input stream into the set IO data collectors. Should always be called after setShardInput(DataInput) and either prepareReductionDataIO(ReductionDataCollection) or newDataCollectionIO() have been called.
    
    Throws:
    
    IOException - if an error occurs while reading the shard data
  - setShardOutput
```
public void setShardOutput(DataOutput output)
```
    Sets the stream to export shard data to.
    
    Parameters:
    
    output - the stream of shard data
  - exportData
```
public void exportData()
                throws IOException
```
    Export the data from the set IO data collectors to the given shard output stream. Should always be called after setShardOutput(DataOutput) and prepareReductionDataIO(ReductionDataCollection).
    
    Throws:
    
    IOException - if an error occurs while writing the shard data
  - prepareReductionDataIO
```
public void prepareReductionDataIO(ReductionCollectionManager.ReductionDataCollection col)
```
    Set the given data collection to be used for either merging or exporting
    
    Parameters:
    
    col - collection to export from or merge to
  - newDataCollectionIO
```
public ReductionCollectionManager.ReductionDataCollection newDataCollectionIO()
```
    Create a new ReductionCollectionManager.ReductionDataCollection to merge to or export from. Mainly used for creating facet value collectors when merging shard data.
    
    Returns:
    
    the new data collection created

Class ReductionCollectionManager

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

reductionDataCollectors

Constructor Detail

ReductionCollectionManager

ReductionCollectionManager

Method Detail

needsCollection

merge

createNewManager

getUsedFields

doSetNextReader

collect

addLastingCollectTarget

clearLastingCollectTargets

newDataCollectionTarget

addCollectTarget

apply

setData

newDataCollection

setShardInput

mergeData

setShardOutput

exportData

prepareReductionDataIO

newDataCollectionIO