Added cache to the common data request

app/helpers/common_data_redis_cache.rb

@@ -0,0 +1,53 @@
+# encoding: utf-8
+
+class CommonDataRedisCache
+
+  # This needs to be changed whenever there're changes in the code that require invalidation of old keys
+  VERSION = '1'
+
+  def initialize(redis_cache = $tables_metadata)
+    @redis = redis_cache
+  end
+
+  def get(is_https_request)
+    key = key(is_https_request)
+    value = redis.get(key)
+    if value.present?
+      return JSON.parse(value, symbolize_names: true)
+    else
+      return nil
+    end
+  rescue Redis::BaseError => exception
+    CartoDB.notify_exception(exception, { key: key })
+    nil
+  end
+
+  def set(is_https_request, response_headers, response_body)
+    serialized = JSON.generate({headers: response_headers,
+                                body: response_body
+                               })
+    redis.setex(key(is_https_request), 6.hours.to_i, serialized)
+  rescue Redis::BaseError => exception
+    CartoDB.notify_exception(exception, { key: key, headers: response_headers, body: response_body })
+    nil
+  end
+
+  def invalidate
+    redis.del [key(is_https_request=true), key(is_https_request=false)]
+  rescue Redis::BaseError => exception
+    CartoDB.notify_exception(exception)
+    nil
+  end
+
+  def key(is_https_request=false)
+    protocol = is_https_request ? 'https' : 'http'
+    "common_data:request:#{protocol}:#{VERSION}"
+  end
+
+  private
+
+  def redis
+    @redis
+  end
+
+end

app/models/common_data.rb

@@ -1,5 +1,6 @@
 require_relative '../../lib/carto/http/client'
 require_relative '../../services/sql-api/sql_api'
+require_relative '../helpers/common_data_redis_cache'
 
 class CommonData
 
@@ -73,15 +74,21 @@ class CommonData
     body = nil
     begin
       http_client = Carto::Http::Client.get('common_data', log_requests: true)
-      response = http_client.request(
+      request = http_client.request(
         @visualizations_api_url,
         method: :get,
         connecttimeout: CONNECT_TIMEOUT,
         timeout: DEFAULT_TIMEOUT,
         params: {per_page: NO_PAGE_LIMIT}
-      ).run
+      )
+      is_https_request = (request.url =~ /^https:\/\//)
+      cached_data = redis_cache.get(is_https_request)
+      return cached_data[:body] unless cached_data.nil?
+      response = request.run
       if response.code == 200
         body = response.response_body
+        redis_cache.set(is_https_request, response.headers, response.response_body)
+        body
       end
     rescue Exception => e
       CartoDB.notify_exception(e)
@@ -111,4 +118,8 @@ class CommonData
       default
     end
   end
+
+  def redis_cache
+    @redis_cache ||= CommonDataRedisCache.new
+  end
 end

spec/models/common_data_spec.rb

@@ -11,6 +11,7 @@ describe CommonData do
     @common_data.stubs(:config).with('base_url').returns(nil)
     @common_data.stubs(:config).with('api_key').returns('wadus')
     @common_data.stubs(:config).with('format', 'shp').returns('shp')
+    CommonDataRedisCache.new.invalidate
   end
 
   after(:all) do