packages/modeldb-sqlite: refactor internal api to use async iterators…

packages/modeldb-sqlite/src/ModelDB.ts

@@ -68,7 +68,10 @@ export class ModelDB extends AbstractModelDB {
 		return api.get(key) as T | null
 	}
 
-	public async *iterate<T extends ModelValue<any> = ModelValue<any>>(modelName: string): AsyncIterable<T> {
+	public async *iterate<T extends ModelValue<any> = ModelValue<any>>(
+		modelName: string,
+		query: QueryParams = {},
+	): AsyncIterable<T> {
 		const api = this.#models[modelName]
 		assert(api !== undefined, `model ${modelName} not found`)
 		yield* api.values() as AsyncIterable<T>

packages/modeldb-sqlite/src/api.ts

@@ -215,6 +215,39 @@ export class ModelAPI {
 	}
 
 	public query(query: QueryParams): ModelValue[] {
+		const [sql, relations, params] = this.parseQuery(query)
+		const results = this.db.prepare(sql).all(params) as RecordValue[]
+		return results.map((record): ModelValue => {
+			const key = record[this.#primaryKeyName]
+			assert(typeof key === "string", 'expected typeof primaryKey === "string"')
+
+			const value: ModelValue = {}
+			for (const [propertyName, propertyValue] of Object.entries(record)) {
+				const property = this.#properties[propertyName]
+				if (property.kind === "primary") {
+					value[propertyName] = decodePrimaryKeyValue(this.model.name, property, propertyValue)
+				} else if (property.kind === "primitive") {
+					value[propertyName] = decodePrimitiveValue(this.model.name, property, propertyValue)
+				} else if (property.kind === "reference") {
+					value[propertyName] = decodeReferenceValue(this.model.name, property, propertyValue)
+				} else if (property.kind === "relation") {
+					throw new Error("internal error")
+				} else {
+					signalInvalidType(property)
+				}
+			}
+
+			for (const relation of relations) {
+				value[relation.property] = this.#relations[relation.property].get(key)
+			}
+
+			return value
+		})
+	}
+
+	private parseQuery(
+		query: QueryParams,
+	): [sql: string, relations: Relation[], params: Record<string, null | number | string | Buffer | boolean>] {
 		// See https://www.sqlite.org/lang_select.html for railroad diagram
 		const sql: string[] = []
 
@@ -262,33 +295,7 @@ export class ModelAPI {
 			params.limit = query.offset
 		}
 
-		const results = this.db.prepare(sql.join(" ")).all(params) as RecordValue[]
-		return results.map((record): ModelValue => {
-			const key = record[this.#primaryKeyName]
-			assert(typeof key === "string", 'expected typeof primaryKey === "string"')
-
-			const value: ModelValue = {}
-			for (const [propertyName, propertyValue] of Object.entries(record)) {
-				const property = this.#properties[propertyName]
-				if (property.kind === "primary") {
-					value[propertyName] = decodePrimaryKeyValue(this.model.name, property, propertyValue)
-				} else if (property.kind === "primitive") {
-					value[propertyName] = decodePrimitiveValue(this.model.name, property, propertyValue)
-				} else if (property.kind === "reference") {
-					value[propertyName] = decodeReferenceValue(this.model.name, property, propertyValue)
-				} else if (property.kind === "relation") {
-					throw new Error("internal error")
-				} else {
-					signalInvalidType(property)
-				}
-			}
-
-			for (const relation of relations) {
-				value[relation.property] = this.#relations[relation.property].get(key)
-			}
-
-			return value
-		})
+		return [sql.join(" "), relations, params]
 	}
 
 	private getSelectExpression(