From 859edeb33138040bf2382688820adccd7aad363e Mon Sep 17 00:00:00 2001
From: Etienne Donneger <etienne@pinax.network>
Date: Wed, 24 Apr 2024 12:32:29 -0400
Subject: [PATCH] Include statistics from ClickHouse in `meta` response field
 (#14)

See #8
---
 src/fetch/balance.ts    |  3 +--
 src/fetch/supply.ts     |  3 +--
 src/fetch/transfers.ts  |  3 +--
 src/fetch/utils.spec.ts | 17 ++++++++++++-----
 src/fetch/utils.ts      | 15 +++++++++------
 5 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/src/fetch/balance.ts b/src/fetch/balance.ts
index d470c97..56172d9 100644
--- a/src/fetch/balance.ts
+++ b/src/fetch/balance.ts
@@ -23,8 +23,7 @@ export default async function (req: Request) {
 
         return toJSON(
             addMetadata(
-                response.data,
-                response.rows_before_limit_at_least,
+                response,
                 parseLimit(searchParams.get("limit")),
                 parsePage(searchParams.get("page"))
             )
diff --git a/src/fetch/supply.ts b/src/fetch/supply.ts
index 280ac50..2838e78 100644
--- a/src/fetch/supply.ts
+++ b/src/fetch/supply.ts
@@ -23,8 +23,7 @@ export default async function (req: Request) {
 
         return toJSON(
             addMetadata(
-                response.data,
-                response.rows_before_limit_at_least,
+                response,
                 parseLimit(searchParams.get("limit")),
                 parsePage(searchParams.get("page"))
             )
diff --git a/src/fetch/transfers.ts b/src/fetch/transfers.ts
index 5ec0b8d..26aaeb5 100644
--- a/src/fetch/transfers.ts
+++ b/src/fetch/transfers.ts
@@ -15,8 +15,7 @@ export default async function (req: Request) {
         
         return toJSON(
             addMetadata(
-                response.data,
-                response.rows_before_limit_at_least,
+                response,
                 parseLimit(searchParams.get("limit")),
                 parsePage(searchParams.get("page"))
             )
diff --git a/src/fetch/utils.spec.ts b/src/fetch/utils.spec.ts
index 06144e9..d4eed9f 100644
--- a/src/fetch/utils.spec.ts
+++ b/src/fetch/utils.spec.ts
@@ -1,33 +1,40 @@
 import { expect, test } from "bun:test";
 import { addMetadata } from "./utils.js";
+import { Query } from "../clickhouse/makeQuery.js";
 
 test("addMetadata pagination", () => {
     const limit = 5;
-    const mock_query_reponse = {
+    const mock_query_reponse: Query<any> = {
+        meta: [],
         data: Array(limit),
         rows: limit,
         rows_before_limit_at_least: 5*limit, // Simulate query with more total results than the query limit making pagination relevant
+        statistics: {
+            elapsed: 0,
+            rows_read: 0,
+            bytes_read: 0,
+        }
     };
 
-    const first_page = addMetadata(mock_query_reponse.data, mock_query_reponse.rows_before_limit_at_least, limit, 1);
+    const first_page = addMetadata(mock_query_reponse, limit, 1);
     expect(first_page.meta.next_page).toBe(2);
     expect(first_page.meta.previous_page).toBe(1); // Previous page should be set to 1 on first page
     expect(first_page.meta.total_pages).toBe(5);
     expect(first_page.meta.total_results).toBe(5*limit);
 
-    const odd_page = addMetadata(mock_query_reponse.data, mock_query_reponse.rows_before_limit_at_least, limit, 3);
+    const odd_page = addMetadata(mock_query_reponse, limit, 3);
     expect(odd_page.meta.next_page).toBe(4);
     expect(odd_page.meta.previous_page).toBe(2);
     expect(odd_page.meta.total_pages).toBe(5);
     expect(odd_page.meta.total_results).toBe(5*limit);
 
-    const even_page = addMetadata(mock_query_reponse.data, mock_query_reponse.rows_before_limit_at_least, limit, 4);
+    const even_page = addMetadata(mock_query_reponse, limit, 4);
     expect(even_page.meta.next_page).toBe(5);
     expect(even_page.meta.previous_page).toBe(3);
     expect(even_page.meta.total_pages).toBe(5);
     expect(even_page.meta.total_results).toBe(5*limit);
 
-    const last_page = addMetadata(mock_query_reponse.data, mock_query_reponse.rows_before_limit_at_least, limit, 5);
+    const last_page = addMetadata(mock_query_reponse, limit, 5);
     expect(last_page.meta.next_page).toBe(last_page.meta.total_pages); // Next page should be capped to total_pages on last page
     expect(last_page.meta.previous_page).toBe(4);
     expect(last_page.meta.total_pages).toBe(5);
diff --git a/src/fetch/utils.ts b/src/fetch/utils.ts
index 2601853..be97426 100644
--- a/src/fetch/utils.ts
+++ b/src/fetch/utils.ts
@@ -1,16 +1,19 @@
+import { Query } from "../clickhouse/makeQuery.js";
+
 export function toJSON(data: any, status: number = 200) {
     return new Response(JSON.stringify(data), { status, headers: { "Content-Type": "application/json" } });
 }
 
-export function addMetadata(data: any[], total_before_limit: number, limit: number, page: number) {
+export function addMetadata(response: Query<any>, req_limit: number, req_page: number) {
     // TODO: Catch page number greater than total_pages and return error
     return {
-        data,
+        data: response.data,
         meta: {
-            "next_page": (page * limit >= total_before_limit) ? page : page + 1,
-            "previous_page": (page <= 1) ? page : page - 1,
-            "total_pages": Math.ceil(total_before_limit / limit),
-            "total_results": total_before_limit
+            statistics: response.statistics,
+            "next_page": (req_page * req_limit >= response.rows_before_limit_at_least) ? req_page : req_page + 1,
+            "previous_page": (req_page <= 1) ? req_page : req_page - 1,
+            "total_pages": Math.ceil( response.rows_before_limit_at_least / req_limit),
+            "total_results": response.rows_before_limit_at_least
         }
     }
 }
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