angel_cache 1.0.0

  • README.md
  • CHANGELOG.md
  • Example
  • Installing
  • Versions
  • 7

cache

Pub build status

Support for server-side caching in Angel.

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 MemcacheD/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.

main() async {
    var app = new Angel()..lazyParseBodies = true;
    
    app.use(
      '/api/todos',
      new CacheService(
        database: new AnonymousService(
          index: ([params]) {
            print('Fetched directly from the underlying service at ${new DateTime.now()}!');
            return ['foo', 'bar', 'baz'];
          },
          read: (id, [params]) {
            return {id: '$id at ${new DateTime.now()}'};
          }
        ),
      ),
    );
}

ResponseCache

A flexible response cache for Angel.

Use this to improve real and perceived response of Web applications, as well as to memoize 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 = new ResponseCache();
  
  // You can also pass an invalidation timeout.
  var cache = new 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',
    new RegExp(r'\.(png|jpg|gif|txt)$'),
    new 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);
}

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 new AngelHttpException.forbidden();
    return cache.purge(req.uri.path);
  });
}

1.0.0

  • First version

example/main.dart

import 'package:angel_cache/angel_cache.dart';
import 'package:angel_framework/angel_framework.dart';
import 'package:glob/glob.dart';

main() async {
  var app = new Angel()..lazyParseBodies = true;

  // Cache a glob
  var cache = new ResponseCache()
    ..patterns.addAll([
      new Glob('/*.txt'),
    ]);

  // Handle `if-modified-since` header, and also send cached content
  app.use(cache.handleRequest);

  // A simple handler that returns a different result every time.
  app.get('/date.txt',
      (ResponseContext res) => res.write(new DateTime.now().toIso8601String()));

  // Support purging the cache.
  app.addRoute('PURGE', '*', (RequestContext req) {
    if (req.ip != '127.0.0.1') throw new AngelHttpException.forbidden();

    cache.purge(req.uri.path);
    print('Purged ${req.uri.path}');
  });

  // The response finalizer that actually saves the content
  app.responseFinalizers.add(cache.responseFinalizer);

  var http = new AngelHttp(app);
  var server = await http.startServer('127.0.0.1', 3000);
  print('Listening at http://${server.address.address}:${server.port}');
}

Use this package as a library

1. Depend on it

Add this to your package's pubspec.yaml file:


dependencies:
  angel_cache: ^1.0.0

2. Install it

You can install packages from the command line:

with pub:


$ pub get

Alternatively, your editor might support pub get. Check the docs for your editor to learn more.

3. Import it

Now in your Dart code, you can use:


import 'package:angel_cache/angel_cache.dart';
  
Version Uploaded Documentation Archive
1.0.0 May 16, 2018 Go to the documentation of angel_cache 1.0.0 Download angel_cache 1.0.0 archive
Popularity:
Describes how popular the package is relative to other packages. [more]
14
Health:
Code health derived from static analysis. [more]
0
Maintenance:
Reflects how tidy and up-to-date the package is. [more]
0
Overall:
Weighted score of the above. [more]
7
Learn more about scoring.

The package version is not analyzed, because it does not support Dart 2. Until this is resolved, the package will receive a health and maintenance score of 0.

Issues and suggestions

Fix platform conflicts.

Error(s) prevent platform classification:

Fix dependencies in pubspec.yaml.

Fix dependencies in pubspec.yaml.

Running pub upgrade failed with the following output:

ERR: The current Dart SDK version is 2.0.0.
 
 Because angel_framework >=0.0.0-dev.1 <1.1.3 requires SDK version <2.0.0 and angel_framework >=1.1.3 <2.0.0-alpha depends on random_string ^0.0.1, angel_framework >=0.0.0-dev.1 <2.0.0-alpha requires random_string ^0.0.1.
 So, because every version of random_string requires SDK version >=1.0.0 <2.0.0 and angel_cache depends on angel_framework ^1.0.0-dev, version solving failed.

The description is too short.

Add more detail about the package, what it does and what is its target use case. Try to write at least 60 characters.

Format lib/angel_cache.dart.

Run dartfmt to format lib/angel_cache.dart.

Format lib/src/cache.dart.

Run dartfmt to format lib/src/cache.dart.

Format lib/src/serializer.dart.

Run dartfmt to format lib/src/serializer.dart.

Format lib/src/util.dart.

Run dartfmt to format lib/src/util.dart.

Dependencies

Package Constraint Resolved Available
Direct dependencies
Dart SDK >=1.19.0 <3.0.0