feat: Return computed distance and set distance thresholds on VectorQ…

…ueries (#2090)

* Return computed distance and set distance thresholds on VectorQueries

dev/src/index.ts

@@ -103,6 +103,7 @@ export type {AggregateQuery} from './reference/aggregate-query';
 export type {AggregateQuerySnapshot} from './reference/aggregate-query-snapshot';
 export type {VectorQuery} from './reference/vector-query';
 export type {VectorQuerySnapshot} from './reference/vector-query-snapshot';
+export type {VectorQueryOptions} from './reference/vector-query-options';
 export {BulkWriter} from './bulk-writer';
 export type {BulkWriterError} from './bulk-writer';
 export type {BundleBuilder} from './bundle';

dev/src/reference/query.ts

@@ -629,6 +629,9 @@ export class Query<
    * @param options - Options control the vector query. `limit` specifies the upper bound of documents to return, must
    * be a positive integer with a maximum value of 1000. `distanceMeasure` specifies what type of distance is calculated
    * when performing the query.
+   *
+   * @deprecated Use the new {@link findNearest} implementation
+   * accepting a single `options` param.
    */
   findNearest(
     vectorField: string | firestore.FieldPath,
@@ -637,30 +640,85 @@ export class Query<
       limit: number;
       distanceMeasure: 'EUCLIDEAN' | 'COSINE' | 'DOT_PRODUCT';
     }
+  ): VectorQuery<AppModelType, DbModelType>;
+
+  /**
+   * Returns a query that can perform vector distance (similarity) search with given parameters.
+   *
+   * The returned query, when executed, performs a distance (similarity) search on the specified
+   * `vectorField` against the given `queryVector` and returns the top documents that are closest
+   * to the `queryVector`.
+   *
+   * Only documents whose `vectorField` field is a {@link VectorValue} of the same dimension as `queryVector`
+   * participate in the query, all other documents are ignored.
+   *
+   * @example
+   * ```
+   * // Returns the closest 10 documents whose Euclidean distance from their 'embedding' fields are closed to [41, 42].
+   * const vectorQuery = col.findNearest({
+   *     vectorField: 'embedding',
+   *     queryVector: [41, 42],
+   *     limit: 10,
+   *     distanceMeasure: 'EUCLIDEAN',
+   *     distanceResultField: 'distance',
+   *     distanceThreshold: 0.125
+   * });
+   *
+   * const querySnapshot = await aggregateQuery.get();
+   * querySnapshot.forEach(...);
+   * ```
+   * @param options - An argument specifying the behavior of the {@link VectorQuery} returned by this function.
+   * See {@link VectorQueryOptions}.
+   */
+  findNearest(
+    options: VectorQueryOptions
+  ): VectorQuery<AppModelType, DbModelType>;
+
+  findNearest(
+    vectorFieldOrOptions: string | firestore.FieldPath | VectorQueryOptions,
+    queryVector?: firestore.VectorValue | Array<number>,
+    options?: {
+      limit?: number;
+      distanceMeasure?: 'EUCLIDEAN' | 'COSINE' | 'DOT_PRODUCT';
+    }
   ): VectorQuery<AppModelType, DbModelType> {
-    validateFieldPath('vectorField', vectorField);
+    if (
+      typeof vectorFieldOrOptions === 'string' ||
+      vectorFieldOrOptions instanceof FieldPath
+    ) {
+      const vqOptions: VectorQueryOptions = {
+        distanceMeasure: options!.distanceMeasure!,
+        limit: options!.limit!,
+        queryVector: queryVector!,
+        vectorField: vectorFieldOrOptions,
+      };
+      return this._findNearest(vqOptions);
+    } else {
+      return this._findNearest(vectorFieldOrOptions as VectorQueryOptions);
+    }
+  }
+
+  _findNearest(
+    options: VectorQueryOptions
+  ): VectorQuery<AppModelType, DbModelType> {
+    validateFieldPath('vectorField', options.vectorField);
 
     if (options.limit <= 0) {
-      throw invalidArgumentMessage('options.limit', 'positive limit number');
+      throw invalidArgumentMessage('limit', 'positive limit number');
     }
 
     if (
-      (Array.isArray(queryVector)
-        ? queryVector.length
-        : queryVector.toArray().length) === 0
+      (Array.isArray(options.queryVector)
+        ? options.queryVector.length
+        : options.queryVector.toArray().length) === 0
     ) {
       throw invalidArgumentMessage(
         'queryVector',
         'vector size must be larger than 0'
       );
     }
 
-    return new VectorQuery<AppModelType, DbModelType>(
-      this,
-      vectorField,
-      queryVector,
-      new VectorQueryOptions(options.limit, options.distanceMeasure)
-    );
+    return new VectorQuery<AppModelType, DbModelType>(this, options);
   }
 
   /**

dev/src/reference/vector-query-options.ts

@@ -14,23 +14,48 @@
  * limitations under the License.
  */
 
-export class VectorQueryOptions {
-  constructor(
-    readonly limit: number,
-    readonly distanceMeasure: 'EUCLIDEAN' | 'COSINE' | 'DOT_PRODUCT'
-  ) {}
+import * as firestore from '@google-cloud/firestore';
 
-  isEqual(other: VectorQueryOptions): boolean {
-    if (this === other) {
-      return true;
-    }
-    if (!(other instanceof VectorQueryOptions)) {
-      return false;
-    }
+/**
+ * Specifies the behavior of the {@link VectorQuery} generated by a call to {@link Query.findNearest}.
+ */
+export interface VectorQueryOptions {
+  /**
+   * A string or {@link FieldPath} specifying the vector field to search on.
+   */
+  vectorField: string | firestore.FieldPath;
+
+  /**
+   * The {@link VectorValue} used to measure the distance from `vectorField` values in the documents.
+   */
+  queryVector: firestore.VectorValue | Array<number>;
+
+  /**
+   * Specifies the upper bound of documents to return, must be a positive integer with a maximum value of 1000.
+   */
+  limit: number;
+
+  /**
+   * Specifies what type of distance is calculated when performing the query.
+   */
+  distanceMeasure: 'EUCLIDEAN' | 'COSINE' | 'DOT_PRODUCT';
+
+  /**
+   * Optionally specifies the name of a field that will be set on each returned DocumentSnapshot,
+   * which will contain the computed distance for the document.
+   */
+  distanceResultField?: string | firestore.FieldPath;
 
-    return (
-      this.limit === other.limit &&
-      this.distanceMeasure === other.distanceMeasure
-    );
-  }
+  /**
+   * Specifies a threshold for which no less similar documents will be returned. The behavior
+   * of the specified `distanceMeasure` will affect the meaning of the distance threshold.
+   *
+   *  - For `distanceMeasure: "EUCLIDEAN"`, the meaning of `distanceThreshold` is:
+   *     SELECT docs WHERE euclidean_distance <= distanceThreshold
+   *  - For `distanceMeasure: "COSINE"`, the meaning of `distanceThreshold` is:
+   *     SELECT docs WHERE cosine_distance <= distanceThreshold
+   *  - For `distanceMeasure: "DOT_PRODUCT"`, the meaning of `distanceThreshold` is:
+   *     SELECT docs WHERE dot_product_distance >= distanceThreshold
+   */
+  distanceThreshold?: number;
 }

dev/src/reference/vector-query.ts

@@ -56,9 +56,7 @@ export class VectorQuery<
    */
   constructor(
     private readonly _query: Query<AppModelType, DbModelType>,
-    private readonly vectorField: string | firestore.FieldPath,
-    private readonly queryVector: firestore.VectorValue | Array<number>,
-    private readonly options: VectorQueryOptions
+    private readonly _options: VectorQueryOptions
   ) {
     this._queryUtil = new QueryUtil<
       AppModelType,
@@ -79,19 +77,31 @@ export class VectorQuery<
    * @internal
    */
   private get _rawVectorField(): string {
-    return typeof this.vectorField === 'string'
-      ? this.vectorField
-      : this.vectorField.toString();
+    return typeof this._options.vectorField === 'string'
+      ? this._options.vectorField
+      : this._options.vectorField.toString();
+  }
+
+  /**
+   * @private
+   * @internal
+   */
+  private get _rawDistanceResultField(): string | undefined {
+    if (typeof this._options.distanceResultField === 'undefined') return;
+
+    return typeof this._options.distanceResultField === 'string'
+      ? this._options.distanceResultField
+      : this._options.distanceResultField.toString();
   }
 
   /**
    * @private
    * @internal
    */
   private get _rawQueryVector(): Array<number> {
-    return Array.isArray(this.queryVector)
-      ? this.queryVector
-      : this.queryVector.toArray();
+    return Array.isArray(this._options.queryVector)
+      ? this._options.queryVector
+      : this._options.queryVector.toArray();
   }
 
   /**
@@ -157,7 +167,7 @@ export class VectorQuery<
   }
 
   /**
-   * Internal method for serializing a query to its RunAggregationQuery proto
+   * Internal method for serializing a query to its proto
    * representation with an optional transaction id.
    *
    * @private
@@ -170,17 +180,25 @@ export class VectorQuery<
   ): api.IRunQueryRequest {
     const queryProto = this._query.toProto(transactionOrReadTime);
 
-    const queryVector = Array.isArray(this.queryVector)
-      ? new VectorValue(this.queryVector)
-      : (this.queryVector as VectorValue);
+    const queryVector = Array.isArray(this._options.queryVector)
+      ? new VectorValue(this._options.queryVector)
+      : (this._options.queryVector as VectorValue);
 
     queryProto.structuredQuery!.findNearest = {
-      limit: {value: this.options.limit},
-      distanceMeasure: this.options.distanceMeasure,
+      limit: {value: this._options.limit},
+      distanceMeasure: this._options.distanceMeasure,
       vectorField: {
-        fieldPath: FieldPath.fromArgument(this.vectorField).formattedName,
+        fieldPath: FieldPath.fromArgument(this._options.vectorField)
+          .formattedName,
       },
       queryVector: queryVector._toProto(this._query._serializer),
+      distanceResultField: this._options?.distanceResultField
+        ? FieldPath.fromArgument(this._options.distanceResultField!)
+            .formattedName
+        : undefined,
+      distanceThreshold: this._options?.distanceThreshold
+        ? {value: this._options?.distanceThreshold}
+        : undefined,
     };
 
     if (explainOptions) {
@@ -253,7 +271,10 @@ export class VectorQuery<
     return (
       this._rawVectorField === other._rawVectorField &&
       isPrimitiveArrayEqual(this._rawQueryVector, other._rawQueryVector) &&
-      this.options.isEqual(other.options)
+      this._options.limit === other._options.limit &&
+      this._options.distanceMeasure === other._options.distanceMeasure &&
+      this._options.distanceThreshold === other._options.distanceThreshold &&
+      this._rawDistanceResultField === other._rawDistanceResultField
     );
   }
 }