PCollectionTuple (Google Cloud Dataflow SDK API)

java.lang.Object
- com.google.cloud.dataflow.sdk.values.PCollectionTuple

All Implemented Interfaces:: PInput, POutput

public class PCollectionTuple
extends java.lang.Object
implements PInput, POutput

A PCollectionTuple is an immutable tuple of heterogeneously-typed PCollections, "keyed" by TupleTags. A PCollectionTuple can be used as the input or output of a PTransform taking or producing multiple PCollection inputs or outputs that can be of different types, for instance a ParDo with side outputs.

PCollectionTuples can be created and accessed like follows:

 PCollection<String> pc1 = ...;
 PCollection<Integer> pc2 = ...;
 PCollection<Iterable<String>> pc3 = ...;

 // Create TupleTags for each of the PCollections to put in the
 // PCollectionTuple (the type of the TupleTag enables tracking the
 // static type of each of the PCollections in the PCollectionTuple):
 TupleTag<String> tag1 = new TupleTag<>();
 TupleTag<Integer> tag2 = new TupleTag<>();
 TupleTag<Iterable<String>> tag3 = new TupleTag<>();

 // Create a PCollectionTuple with three PCollections:
 PCollectionTuple pcs =
     PCollectionTuple.of(tag1, pc1)
                     .and(tag2, pc2)
                     .and(tag3, pc3);

 // Create an empty PCollectionTuple:
 Pipeline p = ...;
 PCollectionTuple pcs2 = PCollectionTuple.empty(p);

 // Get PCollections out of a PCollectionTuple, using the same tags
 // that were used to put them in:
 PCollection<Integer> pcX = pcs.get(tag2);
 PCollection<String> pcY = pcs.get(tag1);
 PCollection<Iterable<String>> pcZ = pcs.get(tag3);

 // Get a map of all PCollections in a PCollectionTuple:
 Map<TupleTag<?>, PCollection<?>> allPcs = pcs.getAll();

Method Summary

Methods
Modifier and Type	Method and Description
`<T> PCollectionTuple`	`and(TupleTag<T> tag, PCollection<T> pc)` Returns a new PCollectionTuple that has all the PCollections and tags of this PCollectionTuple plus the given PCollection and tag.
`<Output extends POutput> Output`	`apply(PTransform<PCollectionTuple,Output> t)` Applies the given PTransform to this input PCollectionTuple, and returns the PTransform's Output.
`static PCollectionTuple`	`empty(Pipeline pipeline)` Returns an empty PCollectionTuple that is part of the given Pipeline.
`java.util.Collection<? extends PValue>`	`expand()` Expands this PInput into a list of its component input PValues.
`void`	`finishSpecifying()` After building, finalizes this PInput to make it ready for being used as an input to a PTransform.
`void`	`finishSpecifyingOutput()` As part of finishing the producing `PTransform`, finalizes this `PTransform` output to make it ready for being used as an input and for running.
`<T> PCollection<T>`	`get(TupleTag<T> tag)` Returns the PCollection with the given tag in this PCollectionTuple.
`java.util.Map<TupleTag<?>,PCollection<?>>`	`getAll()` Returns an immutable Map from TupleTag to corresponding PCollection, for all the members of this PCollectionTuple.
`Pipeline`	`getPipeline()` Returns the owning Pipeline of this PInput.
`<T> boolean`	`has(TupleTag<T> tag)` Returns whether this PCollectionTuple contains a PCollection with the given tag.
`static <T> PCollectionTuple`	`of(TupleTag<T> tag, PCollection<T> pc)` Returns a singleton PCollectionTuple containing the given PCollection keyed by the given TupleTag.
`static PCollectionTuple`	`ofPrimitiveOutputsInternal(TupleTagList outputTags, WindowFn<?,?> windowFn)` Returns a PCollectionTuple with each of the given tags mapping to a new output PCollection.
`void`	`recordAsOutput(Pipeline pipeline, PTransform<?,?> transform)` Records that this `POutput` is an output of the given `PTransform` in the given `Pipeline`.

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

- Method Detail
  - empty
```
public static PCollectionTuple empty(Pipeline pipeline)
```
    Returns an empty PCollectionTuple that is part of the given Pipeline.
    Longer PCollectionTuples can be created by calling and(com.google.cloud.dataflow.sdk.values.TupleTag<T>, com.google.cloud.dataflow.sdk.values.PCollection<T>) on the result.
  - of
```
public static <T> PCollectionTuple of(TupleTag<T> tag,
                      PCollection<T> pc)
```
    Returns a singleton PCollectionTuple containing the given PCollection keyed by the given TupleTag.
    Longer PCollectionTuples can be created by calling and(com.google.cloud.dataflow.sdk.values.TupleTag<T>, com.google.cloud.dataflow.sdk.values.PCollection<T>) on the result.
  - and
```
public <T> PCollectionTuple and(TupleTag<T> tag,
                       PCollection<T> pc)
```
    Returns a new PCollectionTuple that has all the PCollections and tags of this PCollectionTuple plus the given PCollection and tag.
    The given TupleTag should not already be mapped to a PCollection in this PCollectionTuple.
    All the PCollections in the resulting PCollectionTuple must be part of the same Pipeline.
  - has
```
public <T> boolean has(TupleTag<T> tag)
```
    Returns whether this PCollectionTuple contains a PCollection with the given tag.
  - get
```
public <T> PCollection<T> get(TupleTag<T> tag)
```
    Returns the PCollection with the given tag in this PCollectionTuple. Throws IllegalArgumentException if there is no such PCollection, i.e., !has(tag).
  - getAll
```
public java.util.Map<TupleTag<?>,PCollection<?>> getAll()
```
    Returns an immutable Map from TupleTag to corresponding PCollection, for all the members of this PCollectionTuple.
  - apply
```
public <Output extends POutput> Output apply(PTransform<PCollectionTuple,Output> t)
```
    Applies the given PTransform to this input PCollectionTuple, and returns the PTransform's Output.
  - ofPrimitiveOutputsInternal
```
public static PCollectionTuple ofPrimitiveOutputsInternal(TupleTagList outputTags,
                                          WindowFn<?,?> windowFn)
```
    Returns a PCollectionTuple with each of the given tags mapping to a new output PCollection.
    For use by primitive transformations only.
  - getPipeline
```
public Pipeline getPipeline()
```
    Description copied from interface: PInput
    
    Returns the owning Pipeline of this PInput.
    
    Specified by:
    
    getPipeline in interface PInput
  - expand
```
public java.util.Collection<? extends PValue> expand()
```
    Description copied from interface: PInput
    
    Expands this PInput into a list of its component input PValues.
    A PValue expands to itself.
    A tuple or list of PValues (e.g., PCollectionTuple, and PCollectionList) expands to its component PValues.
    Not intended to be invoked directly by user code.
    
    Specified by:
    
    expand in interface PInput
    
    Specified by:
    
    expand in interface POutput
  - recordAsOutput
```
public void recordAsOutput(Pipeline pipeline,
                  PTransform<?,?> transform)
```
    Description copied from interface: POutput
    
    Records that this POutput is an output of the given PTransform in the given Pipeline.
    Should expand this POutput and invoke PValue#recordAsOutput(Pipeline, com.google.cloud.dataflow.sdk.transforms.PTransform, String) on each component output PValue.
    Automatically invoked as part of applying a PTransform. Not to be invoked directly by user code.
    
    Specified by:
    
    recordAsOutput in interface POutput
  - finishSpecifying
```
public void finishSpecifying()
```
    Description copied from interface: PInput
    
    After building, finalizes this PInput to make it ready for being used as an input to a PTransform.
    Automatically invoked whenever apply() is invoked on this PInput, so users do not normally call this explicitly.
    
    Specified by:
    
    finishSpecifying in interface PInput
  - finishSpecifyingOutput
```
public void finishSpecifyingOutput()
```
    Description copied from interface: POutput
    
    As part of finishing the producing PTransform, finalizes this PTransform output to make it ready for being used as an input and for running.
    This includes ensuring that all PCollections have Coders specified or defaulted.
    Automatically invoked whenever this POutput is used as a PInput to another PTransform, or if never used as a PInput, when Pipeline.run() is called, so users do not normally call this explicitly.
    
    Specified by:
    
    finishSpecifyingOutput in interface POutput

Class PCollectionTuple

Method Summary

Methods inherited from class java.lang.Object

Method Detail

empty

of

and

has

get

getAll

apply

ofPrimitiveOutputsInternal

getPipeline

expand

recordAsOutput

finishSpecifying

finishSpecifyingOutput