Make query optimizer pluggable

packages/system/src/query-optimizer/index.ts

@@ -0,0 +1,43 @@
+import { ReqFilter } from "../nostr"
+import { expandFilter } from "./request-expander"
+import { flatMerge, mergeSimilar } from "./request-merger"
+import { diffFilters } from "./request-splitter"
+
+export interface FlatReqFilter {
+  keys: number;
+  ids?: string;
+  authors?: string;
+  kinds?: number;
+  "#e"?: string;
+  "#p"?: string;
+  "#t"?: string;
+  "#d"?: string;
+  "#r"?: string;
+  search?: string;
+  since?: number;
+  until?: number;
+  limit?: number;
+}
+
+export interface QueryOptimizer {
+    expandFilter(f: ReqFilter): Array<FlatReqFilter>
+    getDiff(prev: Array<ReqFilter>, next: Array<ReqFilter>): Array<FlatReqFilter>
+    flatMerge(all: Array<FlatReqFilter>): Array<ReqFilter>
+    compress(all: Array<ReqFilter>): Array<ReqFilter>
+}
+
+export const DefaultQueryOptimizer = {
+    expandFilter: (f: ReqFilter) => {
+      return expandFilter(f);
+    },
+    getDiff: (prev: Array<ReqFilter>, next: Array<ReqFilter>) => {
+      const diff = diffFilters(prev.flatMap(a => expandFilter(a)), next.flatMap(a => expandFilter(a)));
+      return diff.added;
+    },
+    flatMerge: (all: Array<FlatReqFilter>) => {
+      return flatMerge(all);
+    },
+    compress: (all: Array<ReqFilter>) => {
+      return mergeSimilar(all);
+    }
+  } as QueryOptimizer;