Merge pull request #3129 from betagouv/cache-geo-api-requests

Cache Geo Api requests

app/lib/api_geo/api.rb

@@ -1,5 +1,6 @@
 class ApiGeo::API
   TIMEOUT = 15
+  CACHE_DURATION = 1.day
 
   def self.regions
     url = [API_GEO_URL, "regions"].join("/")
@@ -27,6 +28,11 @@ class ApiGeo::API
   end
 
   def self.call(url, body, method = :get)
+    # The cache engine is stored, because as of Typhoeus 1.3.1 the cache engine instance
+    # is included in the computed `cache_key`.
+    # (Which means that when the cache instance changes, the cache is invalidated.)
+    @typhoeus_cache ||= Typhoeus::Cache::SuccessfulRequestsRailsCache.new
+
     response = Typhoeus::Request.new(
       url,
       method: method,
@@ -37,7 +43,9 @@ class ApiGeo::API
       headers: {
         'Accept' => 'application/json',
         'Accept-Encoding' => 'gzip, deflate'
-      }.merge(method == :post ? { 'Content-Type' => 'application/json' } : {})
+      }.merge(method == :post ? { 'Content-Type' => 'application/json' } : {}),
+      cache: @typhoeus_cache,
+      cache_ttl: CACHE_DURATION
     ).run
 
     if response.success?

app/lib/typhoeus/cache/successful_requests_rails_cache.rb

@@ -0,0 +1,21 @@
+module Typhoeus
+  module Cache
+    # Cache successful Typhoeus requests in the Rails cache
+    # (but don’t cache failed requests).
+    #
+    # Usage:
+    #   Typhoeus.config.cache = Typhoeus::Cache::SuccessfulRequestsRailsCache.new
+    #   Typhoeus.get('http://exemple.com/api', cache_ttl: 1.day)
+    class SuccessfulRequestsRailsCache
+      def get(request)
+        ::Rails.cache.read(request)
+      end
+
+      def set(request, response)
+        if response&.success?
+          ::Rails.cache.write(request, response, expires_in: request.cache_ttl)
+        end
+      end
+    end
+  end
+end

spec/lib/typhoeus/cache/successful_requests_rails_cache.rb

@@ -0,0 +1,40 @@
+require 'spec_helper'
+
+describe Typhoeus::Cache::SuccessfulRequestsRailsCache, lib: true do
+  let(:cache) { described_class.new }
+
+  let(:base_url) { "localhost:3001" }
+  let(:request) { Typhoeus::Request.new(base_url, { :method => :get, cache: cache, cache_ttl: 1.day }) }
+  let(:response) { Typhoeus::Response.new(:response_code => response_code, :return_code => 0, :mock => true) }
+  let(:response_code) { 0 }
+
+  before { Rails.cache.clear }
+
+  describe "#set" do
+    context 'when the request is successful' do
+      let(:response_code) { 200 }
+
+      it 'saves the request in the Rails cache' do
+        cache.set(request, response)
+        expect(Rails.cache.exist?(request)).to be true
+        expect(Rails.cache.read(request)).to be_a(Typhoeus::Response)
+      end
+    end
+
+    context 'when the request failed' do
+      let(:response_code) { 500 }
+
+      it 'doesn’t save the request in the Rails cache' do
+        cache.set(request, response)
+        expect(Rails.cache.exist?(request)).to be false
+      end
+    end
+  end
+
+  describe "#get" do
+    it 'returns the request in the cache' do
+      Rails.cache.write(request, response)
+      expect(cache.get(request)).to be_a(Typhoeus::Response)
+    end
+  end
+end