angel3_cache

Description:

angel3 cache

Angel3 HTTP Cache #




A service that provides HTTP caching to the response data for Angel3 framework.
CacheService #
A Service class that caches data from one service, storing it in another. An imaginable use case is storing results from MongoDB or another database in Memcache/Redis.
cacheSerializationResults #
A middleware that enables the caching of response serialization.
This can improve the performance of sending objects that are complex to serialize. You can pass a [shouldCache] callback to determine which values should be cached.
void main() async {
var app = Angel()..lazyParseBodies = true;

app.use(
'/api/todos',
CacheService(
database: AnonymousService(
index: ([params]) {
print('Fetched directly from the underlying service at ${DateTime.now()}!');
return ['foo', 'bar', 'baz'];
},
read: (id, [params]) {
return {id: '$id at ${DateTime.now()}'};
}
),
),
);
}
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ResponseCache #
A flexible response cache for Angel3.
Use this to improve real and perceived response of Web applications, as well as to memorize expensive responses.
Supports the If-Modified-Since header, as well as storing the contents of response buffers in memory.
To initialize a simple cache:
Future configureServer(Angel app) async {
// Simple instance.
var cache = ResponseCache();

// You can also pass an invalidation timeout.
var cache = ResponseCache(timeout: const Duration(days: 2));

// Close the cache when the application closes.
app.shutdownHooks.add((_) => cache.close());

// Use `patterns` to specify which resources should be cached.
cache.patterns.addAll([
'robots.txt',
RegExp(r'\.(png|jpg|gif|txt)$'),
Glob('public/**/*'),
]);

// REQUIRED: The middleware that serves cached responses
app.use(cache.handleRequest);

// REQUIRED: The response finalizer that saves responses to the cache
app.responseFinalizers.add(cache.responseFinalizer);
}
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Purging the Cache #
Call invalidate to remove a resource from a ResponseCache.
Some servers expect a reverse proxy or caching layer to support PURGE requests. If this is your case, make sure to include some sort of validation (maybe IP-based) to ensure no arbitrary attacker can hack your cache:
Future configureServer(Angel app) async {
app.addRoute('PURGE', '*', (req, res) {
if (req.ip != '127.0.0.1')
throw AngelHttpException.forbidden();
return cache.purge(req.uri.path);
});
}
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