FeatureDependencyGraph (feathr-impl 0.10.4-rc1 API)

java.lang.Object
- com.linkedin.feathr.common.FeatureDependencyGraph

```
@InternalApi
public class FeatureDependencyGraph
extends java.lang.Object
```
A dependency graph for feature anchors and feature derivations. Purpose 1: Given a list of features' dependencies and which features are anchored, build a graph that can determine which features are reachable and can resolve features' transitive dependencies on demand. Purpose 2: Given a list of features with entity key bindings (a.k.a. key tags), provide fully expanded list of all transitive dependencies including entity key bindings. E.g. if feature2 depends on feature1, and the request was for [ (a1):feature2, (a2):feature2 ], then the expanded dependencies would be: [ (a1):feature2, (a2):feature2, (a1):feature1, (a2):feature1]

Constructor Summary

Constructors
Constructor and Description
`FeatureDependencyGraph(java.util.Map<java.lang.String,java.util.Set<ErasedEntityTaggedFeature>> dependencyFeatures, java.util.Collection<java.lang.String> anchoredFeatures)` Constructs a FeatureDependencyGraph for a given map of features' dependency relationships and a list of which features are anchored.

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`java.util.List<java.util.Set<TaggedFeatureName>>`	`getComputationPipeline(java.util.Collection<TaggedFeatureName> requestedFeatures)` Return a computation pipeline (a collection of stages that can be computed simultaneously) for the requested features by examining their dependencies and grouping them based on their depth.
`java.util.List<TaggedFeatureName>`	`getOrderedPlanForFeatureUrns(java.util.Collection<TaggedFeatureName> request)` Returns an ordered list of features including the requested features and its dependencies that represents their execution order.
`java.util.List<TaggedFeatureName>`	`getOrderedPlanForRequest(java.util.Collection<TaggedFeatureName> request)` Deprecated.
`java.util.List<java.lang.String>`	`getPlan(java.util.Collection<java.lang.String> features)` Construct a plan for procuring a group of features.
`boolean`	`isDeclared(java.lang.String feature)` Returns whether a given feature name is present in the dependency graph
`boolean`	`isReachable(java.lang.String feature)` Deprecated.
`com.linkedin.feathr.common.FeatureDependencyGraph.Pair<java.lang.Boolean,java.lang.String>`	`isReachableWithErrorMessage(java.lang.String feature)` Returns whether a given feature is reachable
`java.lang.String`	`toString()`

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

- Constructor Detail
  - FeatureDependencyGraph
```
public FeatureDependencyGraph(java.util.Map<java.lang.String,java.util.Set<ErasedEntityTaggedFeature>> dependencyFeatures,
                              java.util.Collection<java.lang.String> anchoredFeatures)
```
    Constructs a FeatureDependencyGraph for a given map of features' dependency relationships and a list of which features are anchored.
    
    Parameters:
    
    dependencyFeatures - Map of derived feature names to their sets of required inputs (described as TaggedFeatureNames)
    
    anchoredFeatures - List of anchored feature names
- Method Detail
  - isDeclared
```
public boolean isDeclared(java.lang.String feature)
```
    Returns whether a given feature name is present in the dependency graph
    
    Parameters:
    
    feature -
    
    Returns:
    
    whether a given feature name is present in the dependency graph
  - isReachable
```
@Deprecated
public boolean isReachable(java.lang.String feature)
```
    Deprecated.
    
    Returns whether a given feature is reachable
    
    Parameters:
    
    feature -
    
    Returns:
    
    isReachable Boolean
  - isReachableWithErrorMessage
```
public com.linkedin.feathr.common.FeatureDependencyGraph.Pair<java.lang.Boolean,java.lang.String> isReachableWithErrorMessage(java.lang.String feature)
```
    Returns whether a given feature is reachable
    
    Parameters:
    
    feature -
    
    Returns:
    
    A Pair of Boolean and String. Boolean indicates if it's reachable and the String indicates the error message if not reachable.
  - getPlan
```
public java.util.List<java.lang.String> getPlan(java.util.Collection<java.lang.String> features)
```
    Construct a plan for procuring a group of features. For a given group of features, what are all the features (transitive dependencies) that need to be procured in order to derive them? This function returns a complete, ordered list of features sufficient to derive the given group of features when evaluated in-order.
    
    Parameters:
    
    features -
    
    Returns:
    
    Ordered list of feature names that can be resolved in-sequence to produce a superset of the given group of features. The returned list is NOT just a re-ordering of the input features, and may contain other features that weren't specifically requested but are required as dependencies. The returned list will always contain all of the features provided in the input.
  - getOrderedPlanForRequest
```
@Deprecated
public java.util.List<TaggedFeatureName> getOrderedPlanForRequest(java.util.Collection<TaggedFeatureName> request)
```
    Deprecated.
    
    Use getOrderedPlanForFeatureUrns(java.util.Collection<com.linkedin.feathr.common.TaggedFeatureName>) instead.
  - getOrderedPlanForFeatureUrns
```
public java.util.List<TaggedFeatureName> getOrderedPlanForFeatureUrns(java.util.Collection<TaggedFeatureName> request)
```
    Returns an ordered list of features including the requested features and its dependencies that represents their execution order. For example, if the feature dependency is A->B, B->C and (A,C) -> D. Then one possible execution order would be: A, B, C, D
  - getComputationPipeline
```
public java.util.List<java.util.Set<TaggedFeatureName>> getComputationPipeline(java.util.Collection<TaggedFeatureName> requestedFeatures)
```
    Return a computation pipeline (a collection of stages that can be computed simultaneously) for the requested features by examining their dependencies and grouping them based on their depth. For each stage, all features will have their direct dependencies resolved from the previous stages so they can be computed simultaneously For example, if the feature dependencies are as follows and features E and F are requested A -> C B -> D (C,D) -> E F Then the result would be returned in the form of an ordered list: [[A,B, F],[C,D],[E]] which represents stage 1: A, B, F stage 2: C, D stage 3: E Disclaimer: the pipeline based approach provides one way to optimize the feature execution and their dependencies but it is by no means the most optimal. For example, in the example above, if A is very slow compared to B and F, then computation of C will be blocked until A is ready. The optimal solution where each feature is computed in isolation all the way from its root dependency.
    
    Returns:
    
    a sorted list of features represents the stages for feature execution
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object

Class FeatureDependencyGraph

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

FeatureDependencyGraph

Method Detail

isDeclared

isReachable

isReachableWithErrorMessage

getPlan

getOrderedPlanForRequest

getOrderedPlanForFeatureUrns

getComputationPipeline

toString