From 98257b470ab565c50afbfc30991b40ccbb0a6097 Mon Sep 17 00:00:00 2001
From: Nicolas Lepage <19571875+nlepage@users.noreply.github.com>
Date: Wed, 16 Oct 2024 13:20:29 +0200
Subject: [PATCH] feat: allow using cache for wasm binary

---
 docs/hello-state-keepalive/index.html | 2 +-
 docs/hello-state-keepalive/sw.js      | 2 +-
 docs/hello-state/sw.js                | 3 ++-
 docs/hello/sw.js                      | 4 ++--
 sw.js                                 | 7 +++++--
 5 files changed, 11 insertions(+), 7 deletions(-)
diff --git a/docs/hello-state-keepalive/index.html b/docs/hello-state-keepalive/index.html
index 2dd8038..53985c5 100644
--- a/docs/hello-state-keepalive/index.html
+++ b/docs/hello-state-keepalive/index.html
@@ -1,7 +1,7 @@
 <!DOCTYPE html>
 <html>
   <head>
-    <title>go-wasm-http-server hello with state demo</title>
+    <title>go-wasm-http-server hello with state and keepalive demo</title>
     <script>
       navigator.serviceWorker.register('sw.js').then(registration => {
         const sw = registration.active ?? registration.installing ?? registration.waiting
diff --git a/docs/hello-state-keepalive/sw.js b/docs/hello-state-keepalive/sw.js
index 60ef0ad..3f8364f 100644
--- a/docs/hello-state-keepalive/sw.js
+++ b/docs/hello-state-keepalive/sw.js
@@ -2,7 +2,7 @@ importScripts('https://cdn.jsdelivr.net/gh/golang/go@go1.23.1/misc/wasm/wasm_exe
 importScripts('https://cdn.jsdelivr.net/gh/nlepage/go-wasm-http-server@v2.0.2/sw.js')
 
 addEventListener('install', event => {
-  event.waitUntil(skipWaiting())
+  event.waitUntil(caches.open('hello-state').then((cache) => cache.add('api.wasm')))
 })
   
 addEventListener('activate', event => {
diff --git a/docs/hello-state/sw.js b/docs/hello-state/sw.js
index 7fd045e..fed8461 100644
--- a/docs/hello-state/sw.js
+++ b/docs/hello-state/sw.js
@@ -2,10 +2,11 @@ importScripts('https://cdn.jsdelivr.net/gh/golang/go@go1.23.1/misc/wasm/wasm_exe
 importScripts('https://cdn.jsdelivr.net/gh/nlepage/go-wasm-http-server@v2.0.2/sw.js')
 
 addEventListener('install', (event) => {
+  event.waitUntil(caches.open('hello-state').then((cache) => cache.add('api.wasm')))
   event.waitUntil(skipWaiting())
 })
   
-addEventListener('activate', event => {
+addEventListener('activate', (event) => {
   event.waitUntil(clients.claim())
 })
 
diff --git a/docs/hello/sw.js b/docs/hello/sw.js
index 02dc53f..0c1a3da 100644
--- a/docs/hello/sw.js
+++ b/docs/hello/sw.js
@@ -2,10 +2,10 @@ importScripts('https://cdn.jsdelivr.net/gh/golang/go@go1.23.1/misc/wasm/wasm_exe
 importScripts('https://cdn.jsdelivr.net/gh/nlepage/go-wasm-http-server@v2.0.2/sw.js')
 
 addEventListener('install', (event) => {
-  event.waitUntil(skipWaiting())
+  event.waitUntil(caches.open('hello').then((cache) => cache.add('api.wasm')))
 })
 
-addEventListener('activate', event => {
+addEventListener('activate', (event) => {
   event.waitUntil(clients.claim())
 })
 
diff --git a/sw.js b/sw.js
index be99f7d..7348a6d 100644
--- a/sw.js
+++ b/sw.js
@@ -1,4 +1,4 @@
-function registerWasmHTTPListener(wasm, { base, args = [] } = {}) {
+function registerWasmHTTPListener(wasm, { base, cacheName, args = [] } = {}) {
   let path = new URL(registration.scope).pathname
   if (base && base !== '') path = `${trimEnd(path, '/')}/${trimStart(base, '/')}`
 
@@ -11,7 +11,10 @@ function registerWasmHTTPListener(wasm, { base, args = [] } = {}) {
 
   const go = new Go()
   go.argv = [wasm, ...args]
-  WebAssembly.instantiateStreaming(fetch(wasm), go.importObject).then(({ instance }) => go.run(instance))
+  const source = cacheName
+    ? caches.open(cacheName).then((cache) => cache.match(wasm)).then((response) => response ?? fetch(wasm))
+    : caches.match(wasm).then(response => (response) ?? fetch(wasm))
+  WebAssembly.instantiateStreaming(source, go.importObject).then(({ instance }) => go.run(instance))
 
   addEventListener('fetch', e => {
     const { pathname } = new URL(e.request.url)
