Class ZeroToManyRelationCountLoader

The 0:many connected vertices counts data loader.

This class aggregates multiple 0:many relationships counters retrievals into a single Gremlin query.

The logic is similar to the ZeroToManyRelationVertexLoader; in most cases, while not guaranteed, counters and vertices queries would be aggregated by same keys.

Check ZeroToManyRelationLoaderDataLoaderId type and serializeDataLoaderId method for details on what properties are used for aggregating queries.

Mermaid

Retrieving 0:many connections counters

%%{init:{"theme":"dark"}}%% sequenceDiagram participant Resolvers participant ZeroToManyRelationCountLoader participant Graph database Resolvers->>ZeroToManyRelationCountLoader: Retrieve

%%{init:{"theme":"default"}}%% sequenceDiagram participant Resolvers participant ZeroToManyRelationCountLoader participant Graph database Resolvers->>ZeroToManyRelationCountLoader: Retrieve

sequenceDiagram
    participant Resolvers
    participant ZeroToManyRelationCountLoader
    participant Graph database
    Resolvers->>ZeroToManyRelationCountLoader: Retrieve

`a` connections count for vertex 1 ZeroToManyRelationCountLoader->>Resolvers: Promise Resolvers->>ZeroToManyRelationCountLoader: Retrieve `a` connections count for vertex 2 ZeroToManyRelationCountLoader->>Resolvers: Promise Resolvers->>ZeroToManyRelationCountLoader: Retrieve `a` connections count for vertex 3 ZeroToManyRelationCountLoader->>Resolvers: Promise Resolvers->>ZeroToManyRelationCountLoader: Retrieve `b` connections count for vertex 4 ZeroToManyRelationCountLoader->>Resolvers: Promise activate ZeroToManyRelationCountLoader Note left of ZeroToManyRelationCountLoader: Aggregates requests until next event loop tick ZeroToManyRelationCountLoader->>Graph database: Retrieve count of `a` connections for vertices 1, 2, 3 ZeroToManyRelationCountLoader->>Graph database: Retrieve count of `b` connections for vertex 4 Graph database->>ZeroToManyRelationCountLoader: Response: connections count for vertices 1, 2, 3 Graph database->>ZeroToManyRelationCountLoader: Response: connections count for vertex 4 Note left of ZeroToManyRelationCountLoader: Resolves Promises deactivate ZeroToManyRelationCountLoader ZeroToManyRelationCountLoader->>Resolvers: `a` connections count for vertex 1 ZeroToManyRelationCountLoader->>Resolvers: `a` connections count for vertex 2 ZeroToManyRelationCountLoader->>Resolvers: `a` connections count for vertex 3 ZeroToManyRelationCountLoader->>Resolvers: `b` connections count for vertex 4

Hierarchy

ZeroToManyRelationLoaderBase<ZeroToManyRelationLoaderDataLoaderId, number>
- ZeroToManyRelationCountLoader

Index

Constructors

constructor

new ZeroToManyRelationCountLoader(graphConnector: GraphConnector, search: Search): ZeroToManyRelationCountLoader
Parameters
- graphConnector: GraphConnector
- search: Search
Returns ZeroToManyRelationCountLoader
Overrides ZeroToManyRelationLoaderBase.constructor
- Defined in src/backends/dataLoaders/connectedVertices/ZeroToManyRelationCountLoader.ts:61

Properties

`Protected` graphConnector

graphConnector: GraphConnector

`Protected` search

search: Search

Methods

`Protected` buildDataLoader

buildDataLoader(context: KosmosUserContext<object>, __namedParameters: ZeroToManyRelationVertexLoaderDataLoaderId): BatchLoader<ZeroToManyRelationLoaderDataItemId, number>
Builds DataLoader.

Should be overridden in child classes.
Parameters
- context: KosmosUserContext<object>
  
  The user context.
- __namedParameters: ZeroToManyRelationVertexLoaderDataLoaderId
  
  Class-specific DataLoader ID parameters.
Returns BatchLoader<ZeroToManyRelationLoaderDataItemId, number>
Overrides ZeroToManyRelationLoaderBase.buildDataLoader
- Defined in src/backends/dataLoaders/connectedVertices/ZeroToManyRelationCountLoader.ts:71

clearCache

clearCache(context: KosmosUserContext<object>): void
Clears per-request data loaders cache.
Parameters
- context: KosmosUserContext<object>
  
  The user context.
Returns void
Inherited from ZeroToManyRelationLoaderBase.clearCache
- Defined in src/backends/dataLoaders/LoaderBase.ts:136

`Protected` getDataLoader

getDataLoader(context: KosmosUserContext<object>, params: ZeroToManyRelationLoaderDataLoaderId): KosmosDataLoader<ZeroToManyRelationLoaderDataItemId, number>
Returns DataLoader instance.
Parameters
- context: KosmosUserContext<object>
  
  The user context.
- params: ZeroToManyRelationLoaderDataLoaderId
  
  Class specific params required to identify the DataLoader instance.
Returns KosmosDataLoader<ZeroToManyRelationLoaderDataItemId, number>
Inherited from ZeroToManyRelationLoaderBase.getDataLoader
- Defined in src/backends/dataLoaders/LoaderBase.ts:87

`Protected` getDataLoadersMap

getDataLoadersMap(context: KosmosUserContext<object>): Map<undefined | string, KosmosDataLoader<TItemId, TRetrievedItem>>
Returns a map of DataLoaders for the given request.
Parameters
- context: KosmosUserContext<object>
  
  The user context.
Returns Map<undefined | string, KosmosDataLoader<TItemId, TRetrievedItem>>
Inherited from ZeroToManyRelationLoaderBase.getDataLoadersMap
- Defined in src/backends/dataLoaders/LoaderBase.ts:116

retrieveItem

retrieveItem(context: KosmosUserContext<object>, requestParams: ZeroToManyRelationLoaderDataLoaderId & ZeroToManyRelationLoaderDataItemId, transformParams?: {}): Promise<null | number>
Retrieves an item using DataLoader.

Returns
The class specific response type or NULL.
Parameters
- context: KosmosUserContext<object>
  
  The user context.
- requestParams: ZeroToManyRelationLoaderDataLoaderId & ZeroToManyRelationLoaderDataItemId
  
  Class specific request parameters.
- Optional transformParams: {}
  
  Class specific response item transformation params.
Returns Promise<null | number>
Inherited from ZeroToManyRelationLoaderBase.retrieveItem
- Defined in src/backends/dataLoaders/LoaderBase.ts:71

`Protected` serializeDataItemId

serializeDataItemId(__namedParameters: ZeroToManyRelationLoaderDataItemId): string
Serializes retrieved item ID to a string.
Parameters
- __namedParameters: ZeroToManyRelationLoaderDataItemId
Returns string
Inherited from ZeroToManyRelationLoaderBase.serializeDataItemId
- Defined in src/backends/dataLoaders/connectedVertices/ZeroToManyRelationLoaderBase.ts:65

`Protected` serializeDataLoaderId

serializeDataLoaderId(__namedParameters: ZeroToManyRelationLoaderDataLoaderId): string
Serializes Data Loader ID to a string.
Parameters
- __namedParameters: ZeroToManyRelationLoaderDataLoaderId
Returns string
Overrides ZeroToManyRelationLoaderBase.serializeDataLoaderId
- Defined in src/backends/dataLoaders/connectedVertices/ZeroToManyRelationCountLoader.ts:121

`Protected` storageName

storageName(): string
The unique name of the in-context storage used by this specific Loader service.

Returns string
Inherited from ZeroToManyRelationLoaderBase.storageName
- Defined in src/backends/dataLoaders/LoaderBase.ts:191

`Protected` transform

transform(item: null | number, context: KosmosUserContext<object>, dataLoaderId: ZeroToManyRelationLoaderDataLoaderId, params?: {}): null | number | Promise<null | number>
The return value transformation callback.

Called after the item was retrieved from DataLoader. Child classes may override this method to perform transformation of the data being returned.
Parameters
- item: null | number
  
  The item being retrieved from DataLoader.
- context: KosmosUserContext<object>
  
  The user context.
- dataLoaderId: ZeroToManyRelationLoaderDataLoaderId
  
  The DataLoader identifier object which may contain properties used to initialize the Data Loader.
- Optional params: {}
  
  Class-specific transformation params.
Returns null | number | Promise<null | number>
Inherited from ZeroToManyRelationLoaderBase.transform
- Defined in src/backends/dataLoaders/LoaderBase.ts:154

Class ZeroToManyRelationCountLoader

Mermaid

Retrieving 0:many connections counters

Hierarchy

Index

Constructors

Properties

Methods

Constructors

constructor

Parameters

graphConnector: GraphConnector

search: Search

Returns ZeroToManyRelationCountLoader

Properties

Protected graphConnector

Protected search

Methods

Protected buildDataLoader

Parameters

context: KosmosUserContext<object>

__namedParameters: ZeroToManyRelationVertexLoaderDataLoaderId

Returns BatchLoader<ZeroToManyRelationLoaderDataItemId, number>

clearCache

Parameters

context: KosmosUserContext<object>

Returns void

Protected getDataLoader

Parameters

context: KosmosUserContext<object>

params: ZeroToManyRelationLoaderDataLoaderId

Returns KosmosDataLoader<ZeroToManyRelationLoaderDataItemId, number>

Protected getDataLoadersMap

Parameters

context: KosmosUserContext<object>

Returns Map<undefined | string, KosmosDataLoader<TItemId, TRetrievedItem>>

retrieveItem

Returns

Parameters

context: KosmosUserContext<object>

requestParams: ZeroToManyRelationLoaderDataLoaderId & ZeroToManyRelationLoaderDataItemId

Optional transformParams: {}

Returns Promise<null | number>

Protected serializeDataItemId

Parameters

__namedParameters: ZeroToManyRelationLoaderDataItemId

Returns string

Protected serializeDataLoaderId

Parameters

__namedParameters: ZeroToManyRelationLoaderDataLoaderId

Returns string

Protected storageName

Returns string

Protected transform

Parameters

item: null | number

context: KosmosUserContext<object>

dataLoaderId: ZeroToManyRelationLoaderDataLoaderId

Optional params: {}

Returns null | number | Promise<null | number>

Settings

Member Visibility

Theme

`Protected` graphConnector

`Protected` search

`Protected` buildDataLoader

`Protected` getDataLoader

`Protected` getDataLoadersMap

`Optional` transformParams: {}

`Protected` serializeDataItemId

`Protected` serializeDataLoaderId

`Protected` storageName

`Protected` transform

`Optional` params: {}