SvelteKit and retrieving images from PostgreSQL via node-postgres - endpoint

Question

Storing ~100 JPEGs (24K-100K each) in a table in PostgreSQL as a bytea column.
The <img/> tag src attributes reference the SvelteKit endpoint:
<img src="/api/file/18.json" alt="Person"/>
Getting this error:
Invalid response from route /api/file/76.json: Uint8Array body must be accompanied by content-type: application/octet-stream header
export async function get({ params }) {
const { id } = params
const sql = `SELECT _id, name, type, data FROM files WHERE _id = $1;`
const { rows } = await db.query(sql, [id])
const file = rows[0]
return {
headers: {
'Content-disposition': `attachment; filename=${file.name}`,
'Content-type': file.type
},
body: file.data
}
}
As SvelteKit endpoints don't interact with req/res objects because they're only available on certain platforms, I can't just write out the bytea value as a stream to a response object but I'm not sure what the right approach is.
Also tried this SQL statement...
SELECT _id, name, type, encode(data, 'base64') as data FROM files WHERE _id = $1;
But it didn't help.
Any thoughts?
UPDATE: The problem may be related to a SvelteKit bug - see https://github.com/sveltejs/kit/issues/1438.

Answer 1

The limitation in SvelteKit was resolved on June 11th. I also needed to put the file.data in a new Uint8Array...
// routes/api/file/[filenum].ts
import type { RequestHandler } from '#sveltejs/kit'
import { query } from '../_db'
export const get: RequestHandler = async ({ params }) => {
const { filenum } = params
const { rows } = await query(`SELECT * FROM find_file($1);`, [filenum])
if (rows) {
const file = rows[0]
return {
headers: {
'Content-Disposition': `attachment; filename="${file.name}"`,
'Content-Type': file.type
},
body: new Uint8Array(file.data)
}
} else return {
status: 404
}
}
Here's source for the find_file() function in PostgreSQL:
CREATE OR REPLACE FUNCTION public.find_file(
integer,
OUT _id integer,
OUT name character varying,
OUT type character varying,
OUT data bytea)
RETURNS record
LANGUAGE 'sql'
COST 100
VOLATILE PARALLEL UNSAFE
AS $BODY$
SELECT _id, name, type, data FROM files WHERE _id = $1 LIMIT 1
$BODY$;
and the query() function...
import pg from 'pg'
const pgNativePool = new pg.native.Pool({
max: 10, // default
connectionString: <string> import.meta.env.VITE_DATABASE_URL,
ssl: {
rejectUnauthorized: false
}
})
type QueryResponse = (sql: string, params?: Array<any>) => Promise<pg.QueryResult<any>>
export const query: QueryResponse = (sql: string, params?: Array<any>) => pgNativePool.query(sql, params)