feat: Add database connection handling to server hooks

src/app.d.ts

@@ -1,9 +1,13 @@
 // See https://kit.svelte.dev/docs/types#app
 // for information about these interfaces
+import { Database } from 'pg';
+
 declare global {
 	namespace App {
 		// interface Error {}
-		// interface Locals {}
+		interface Locals {
+      db: any;
+    }
 		// interface PageData {}
 		// interface PageState {}
 		// interface Platform {}

src/hooks.server.ts

@@ -0,0 +1,10 @@
+import type { Handle } from '@sveltejs/kit'
+import { getConnection } from '$lib/server/database/get_connection'
+
+export const handle: Handle = async ({ event, resolve }) => {
+  const pg = getConnection();
+  event.locals.db = pg;
+
+  const result = await resolve(event);
+  return result;
+}

src/lib/server/database.ts

@@ -1,21 +1,12 @@
 import pg from 'pg';
-const { Pool } = pg;
+import { Pool } from 'pg';
+import { getConnection } from './database/get_connection';
 
-import {
+export class Postgres {
-  PG_USER,
-  PG_PASS,
-  PG_HOST,
-  PG_PORT,
-  PG_DB,
-} from '$env/static/private'
-const connectionString = `postgres://${PG_USER}:${PG_PASS}@${PG_HOST}:${PG_PORT}/${PG_DB}`;
-
-const pool = new Pool({ connectionString });
-class Postgres {
   client: pg.PoolClient | null = null;
-  public static async new() {
+  public static async new(pool: Pool) {
     const pg = new Postgres();
-    pg.client = await pool.connect();
+    pg.client = await getConnection().connect();
     return pg;
   }
 
@@ -40,8 +31,10 @@ class Postgres {
   }
 }
 
-export default async () => { return await Postgres.new(); }
+export default async (
-
+  pool: Pool
+) => { return await Postgres.new(pool); };
 
+import { building } from '$app/environment';
 import init from '$lib/server/database/init_db';
-await init();
+if (!building) await init(await Postgres.new(getConnection()));

src/lib/server/database/get_connection.ts

@@ -0,0 +1,15 @@
+import pg from 'pg';
+const { Pool } = pg;
+
+import {
+  PG_USER,
+  PG_PASS,
+  PG_HOST,
+  PG_PORT,
+  PG_DB,
+} from '$env/static/private'
+const connectionString = `postgres://${PG_USER}:${PG_PASS}@${PG_HOST}:${PG_PORT}/${PG_DB}`;
+
+const pool = new Pool({ connectionString });
+
+export const getConnection = () => pool;

src/lib/server/database/init_db.ts

@@ -1,10 +1,9 @@
 // initialize
 import PG from '$lib/server/database';
+import type { Postgres } from '$lib/server/database';
 import fs from 'fs';
 import { compile } from 'mdsvex';
-
+export default async function init(db: Postgres) {
-export default async function init() {
-
   // Create tables(when not exists)
   const schemas = [
     {
@@ -73,9 +72,9 @@ export default async function init() {
     }
   ];
 
-  const db = await PG();
+  await db.begin();
   try {
-    await db.begin();
+    // Create tables
     for (const schema of schemas) {
       const res = await db.query(`select * from information_schema.tables where table_name = '${schema.name}'`)
       if (res.rowCount == 0) {
@@ -87,68 +86,69 @@ export default async function init() {
       }
     }
     await db.commit();
+
+    const articleFiles: ArticleFileItem[] = [];
+    function scanDir(path: string) {
+      const files = fs.readdirSync(path);
+      for (const file of files) {
+        const dir = `${path}/${file}`;
+        const stat = fs.statSync(dir);
+        if (stat.isDirectory()) {
+          scanDir(dir);
+        } else {
+          articleFiles.push({ path: `${path}/${file}`, id: file });
+        }
+      }
+    }
+    scanDir('./articles/article');
+
+    await db.query('update tag set ref_count = 0');
+    db.commit();
+
+    for (const { path, id } of articleFiles) {
+      const res = await db.query('select * from article where id = $1', [id]);
+      const compiled = await compile(fs.readFileSync(path, 'utf-8'));
+      const title = compiled.data.fm.title;
+      const category = path.split('/')[3];
+      const tags: string[] = compiled.data.fm.tags;
+      const released_at = new Date(compiled.data.fm.released_at);
+      const updated_at = new Date(compiled.data.fm.updated_at);
+      const image = compiled.data.fm.image;
+      const publish = compiled.data.fm.publish;
+      const content = compiled.code
+        .replace(/>{@html `<code class="language-/g, '><code class="language-')
+        .replace(/<\/code>`}<\/pre>/g, '</code></pre>');
+      if (res.rowCount == 0) {
+        console.log(`New article: ${id}`);
+        await db.query(
+          'insert into article (id, title, category, released_at, updated_at, tags, image, publish, content) values ($1, $2, $3, $4, $5, $6, $7, $8, $9)',
+          [id, title, category, released_at, updated_at, tags, image, publish, content]
+        );
+      } else if (res.rows[0].updated_at < updated_at) {
+        console.log(`Update article: ${id}`);
+        await db.query(
+          'update article set title = $2, updated_at = $4, tags = $5, content = $6 where id = $1',
+          [id, title, updated_at, tags, content]
+        );
+      } else {
+        console.log(`Article ${id} is already up-to-date`);
+      }
+      for (const tag of tags) {
+        if ((await db.query('select * from tag where name = $1', [tag])).rowCount == 0) {
+          db.query('insert into tag (name, ref_count) values ($1, 1)', [tag]);
+        } else {
+          db.query('update tag set ref_count = ref_count + 1 where name = $1', [tag]);
+        }
+      }
+    }
+    await db.commit();
+
   } catch (err) {
     console.error(err);
     await db.rollback();
+  } finally {
+    await db.release();
   }
-
-  const articleFiles: ArticleFileItem[] = [];
-  function scanDir(path: string) {
-    const files = fs.readdirSync(path);
-    for (const file of files) {
-      const dir = `${path}/${file}`;
-      const stat = fs.statSync(dir);
-      if (stat.isDirectory()) {
-        scanDir(dir);
-      } else {
-        articleFiles.push({ path: `${path}/${file}`, id: file });
-      }
-    }
-  }
-  scanDir('./articles/article');
-
-  await db.query('update tag set ref_count = 0');
-  db.commit();
-
-  for (const { path, id } of articleFiles) {
-    const res = await db.query('select * from article where id = $1', [id]);
-    const compiled = await compile(fs.readFileSync(path, 'utf-8'));
-    const title = compiled.data.fm.title;
-    const category = path.split('/')[3];
-    const tags: string[] = compiled.data.fm.tags;
-    const released_at = new Date(compiled.data.fm.released_at);
-    const updated_at = new Date(compiled.data.fm.updated_at);
-    const image = compiled.data.fm.image;
-    const publish = compiled.data.fm.publish;
-    const content = compiled.code
-      .replace(/>{@html `<code class="language-/g, '><code class="language-')
-      .replace(/<\/code>`}<\/pre>/g, '</code></pre>');
-    if (res.rowCount == 0) {
-      console.log(`New article: ${id}`);
-      await db.query(
-        'insert into article (id, title, category, released_at, updated_at, tags, image, publish, content) values ($1, $2, $3, $4, $5, $6, $7, $8, $9)',
-        [id, title, category, released_at, updated_at, tags, image, publish, content]
-      );
-    } else if (res.rows[0].updated_at < updated_at) {
-      console.log(`Update article: ${id}`);
-      await db.query(
-        'update article set title = $2, updated_at = $4, tags = $5, content = $6 where id = $1',
-        [id, title, updated_at, tags, content]
-      );
-    } else {
-      console.log(`Article ${id} is already up-to-date`);
-    }
-    for (const tag of tags) {
-      if ((await db.query('select * from tag where name = $1', [tag])).rowCount == 0) {
-        db.query('insert into tag (name, ref_count) values ($1, 1)', [tag]);
-      } else {
-        db.query('update tag set ref_count = ref_count + 1 where name = $1', [tag]);
-      }
-    }
-  }
-
-  await db.commit();
-  await db.release();
 }
 
 type ArticleFileItem = {

src/routes/+page.server.ts

@@ -18,8 +18,8 @@ let data: {
   updated: "",
 };
 
-export const load: PageServerLoad = async ({ params }) => {
+export const load: PageServerLoad = async ({ params, locals }) => {
-  const db = await PG();
+  const db = await PG(locals.db);
   await db.begin();
   try {
     const recent_articles = await db.query(

src/routes/article/[category]/[id]/+page.server.ts

@@ -3,11 +3,11 @@ import type { PageServerLoad } from './$types';
 import PG from '$lib/server/database';
 import { error } from '@sveltejs/kit';
 
-export const load: PageServerLoad = async ({ params }) => {
+export const load: PageServerLoad = async ({ params, locals }) => {
   const { category, id } = params;
   console.log(id);
 
-  const db = await PG();
+  const db = await PG(locals.db);
   await db.begin();
   try {
     const article = await db.query(

src/routes/article/[category]/[series]/[id]/+page.server.ts

@@ -3,11 +3,11 @@ import type { PageServerLoad } from './$types';
 import PG from '$lib/server/database';
 import { error } from '@sveltejs/kit';
 
-export const load: PageServerLoad = async ({ params }) => {
+export const load: PageServerLoad = async ({ params, locals }) => {
   const { category, id, series } = params;
   console.log(id);
 
-  const db = await PG();
+  const db = await PG(locals.db);
   await db.begin();
   try {
     const article = await db.query(