public static class Combine.PerKeyWithHotKeyFanout<K,InputT,OutputT> extends PTransform<PCollection<KV<K,InputT>>,PCollection<KV<K,OutputT>>>
Combine.PerKey
, but sharding the combining of hot keys.name
Modifier and Type | Method and Description |
---|---|
PCollection<KV<K,OutputT>> |
expand(PCollection<KV<K,InputT>> input)
Override this method to specify how this
PTransform should be expanded on the given
InputT . |
protected java.lang.String |
getKindString()
Returns the name to use by default for this
PTransform (not including the names of any
enclosing PTransform s). |
void |
populateDisplayData(DisplayData.Builder builder)
Register display data for the given transform or component.
|
compose, getAdditionalInputs, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getName, toString, validate
protected java.lang.String getKindString()
PTransform
PTransform
(not including the names of any
enclosing PTransform
s).
By default, returns the base name of this PTransform
's class.
The caller is responsible for ensuring that names of applied PTransform
s are unique,
e.g., by adding a uniquifying suffix when needed.
getKindString
in class PTransform<PCollection<KV<K,InputT>>,PCollection<KV<K,OutputT>>>
public PCollection<KV<K,OutputT>> expand(PCollection<KV<K,InputT>> input)
PTransform
PTransform
should be expanded on the given
InputT
.
NOTE: This method should not be called directly. Instead apply the PTransform
should
be applied to the InputT
using the apply
method.
Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).
expand
in class PTransform<PCollection<KV<K,InputT>>,PCollection<KV<K,OutputT>>>
public void populateDisplayData(DisplayData.Builder builder)
PTransform
populateDisplayData(DisplayData.Builder)
is invoked by Pipeline runners to collect
display data via DisplayData.from(HasDisplayData)
. Implementations may call super.populateDisplayData(builder)
in order to register display data in the current namespace,
but should otherwise use subcomponent.populateDisplayData(builder)
to use the namespace
of the subcomponent.
By default, does not register any display data. Implementors may override this method to provide their own display data.
populateDisplayData
in interface HasDisplayData
populateDisplayData
in class PTransform<PCollection<KV<K,InputT>>,PCollection<KV<K,OutputT>>>
builder
- The builder to populate with display data.HasDisplayData