Cad an difríochtaí idir na runtimes Edge agus Node.js?

Question

Accepted Answer

Is féidir le Next.js cód fréasúra a dhéanamh ar dhá runtime. Is an **Node.js runtime** (réamhshocrú) an timpeallacht Node iomlán; is timpeallacht éadrom-meáchain, bhunaithe ar V8, an **Edge runtime** a ritheann in áiteanna edge dáilte go domhanda gar do úsáideoirí.

## Runtime a roghnú

```ts
// per route handler / page
export const runtime = "edge";   // or "nodejs" (the default)
```

## Na malartuithe

```text
                  Node.js runtime         Edge runtime
────────────────────────────────────────────────────────────────
APIs              full Node (fs, crypto,  Web APIs only (fetch,
                  Buffer, native modules) Request/Response) — limited
npm packages      all                     only those without Node APIs
Cold start        slower, heavier         near-zero, lightweight
Location          regional (one region)   global (near the user)
Latency to user   higher if far away      very low (geo-distributed)
Execution limits  longer, more memory     short CPU time, less memory
Database          direct TCP connections  HTTP-based DBs only (no raw TCP)
```

## Cathain a úsáid Edge

```text
✓ Middleware (auth checks, redirects, geo-routing) — must be fast & global
✓ Simple, latency-sensitive endpoints (personalization, A/B, feature flags)
✓ Reading geolocation/headers to tailor responses
```

Bíonn Edge go hiontach do **loighic éadrom-meáchain a bhíonn tairbhiúil a bheith gar don úsáideoir** agus do thosuithe fuar meandarach.

## Cathain a úsáid Node.js

```text
✓ Direct database connections (Prisma over TCP, etc.)
✓ Heavy computation, large dependencies, native modules
✓ Anything using Node-specific APIs (fs, crypto.randomBytes via Node, Buffer)
```

## Samplaí srianta réadúil

```ts
export const runtime = "edge";
import fs from "fs";           // ❌ not available on Edge — build/runtime error
import { PrismaClient } from "@prisma/client"; // ⚠️ needs HTTP/data-proxy on Edge
```

Níl go leor leabharlanna coitianta (ina bhraithithe ORMs a osclaíonn soicéid DB amh) in ann oibriú ar Edge gan adapóir bhunaithe ar HTTP — drochbhealach coitianta.

## Cén fáth a bhfuil sé tábhachtach

Is cinneadh réadúil ailtireachta a bhíonn ann an runtime a roghnú: **Edge** do loighic thapa, dhomhanda, éadrom-meáchain (go háirithe middleware) le dtosuithe fuar íosta, **Node.js** do rochtain API iomlán, naisc DB dhíreacha, agus obair throm.

A fhios a bheith agat ar shrianta Edge (Web APIs amháin, gan TCP amh, forghníomhú gearr) a chur i ngleic leis an botún minic a chur cód trom-bhunachar nó cód ag brath ar Node ar runtime nach féidir a thacú leis.