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Module

x/kv_storage/adapters/postgres.ts

An implementation of the StorageArea interface for Deno.
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// deno-lint-ignore-file no-explicit-anyimport { Client } from "https://deno.land/x/postgres@v0.15.0/mod.ts";
import type { Adapter, AdapterParams } from './mod.ts';
const CREATE = 'CREATE TABLE IF NOT EXISTS kv_storage (area TEXT, key TEXT, value TEXT, PRIMARY KEY (area, key))';const GET = 'SELECT value FROM kv_storage WHERE key=$2 AND area=$1';const UPSERT = 'INSERT INTO kv_storage (area, key, value) VALUES ($1, $2, $3) ON CONFLICT(area, key) DO UPDATE SET value=$3';const DELETE = 'DELETE FROM kv_storage WHERE key=$2 AND area=$1';const CLEAR = 'DELETE FROM kv_storage WHERE area=$1';const KEYS = 'SELECT key FROM kv_storage WHERE area=$1';const VALUES = 'SELECT value FROM kv_storage WHERE area=$1';const ENTRIES = 'SELECT key, value FROM kv_storage WHERE area=$1';
export class PostgresAdapter implements Adapter { private area: string; private url: string; private init: Promise<void>; private client?: Client;
constructor({ area, url }: AdapterParams) { this.area = area; this.url = url;
this.init = (async () => { const client = this.client = new Client(url); await client.connect(); // https://stackoverflow.com/questions/26150758/suppressing-notice-relation-exists-when-using-create-if-not-exists await client.queryArray(`SET client_min_messages = warning`); await client.queryArray(CREATE); this.keepOpen() })(); }
private keepOpen() { queueMicrotask(() => { if (this.client?.connected) this.client.end() delete this.client; }) }
private async query(query: string, { key, value }: { key?: string, value?: string } = {}) { await this.init; const client = this.client ||= new Client(this.url); if (!client.connected) await client.connect(); const ret = (await client.queryArray<any>({ text: query, args: [this.area, ...key ? [key] : [], ...value ? [value] : []], })).rows; this.keepOpen() return ret; }
async get(key: string): Promise<string | undefined> { const res = (await this.query(GET, { key }))[0]?.[0]; this.keepOpen() return res; }
async set(key: string, value: string) { await this.query(UPSERT, { key, value }); this.keepOpen() }
async delete(key: string) { await this.query(DELETE, { key }); this.keepOpen() }
async clear() { await this.query(CLEAR); this.keepOpen() }
async *keys() { try { for (const [key] of await this.query(KEYS)) { yield key; } } finally { this.keepOpen() } }
async *values() { try { for (const [value] of await this.query(VALUES)) { yield value; } } finally { this.keepOpen() } }
async *entries() { try { for (const [key, value] of await this.query(ENTRIES)) { yield [key, value] as [string, string]; } } finally { this.keepOpen() } }
backingStore() { return new Client(this.url); }}
// @ts-ignore: ...(globalThis.deno_storage_area__adapters ||= new Map()).set('postgres:', PostgresAdapter);