feat: add cache tag support to allow context-aware caching (#498)

Author: factyy

lib/graphiti/resource/interface.rb

@@ -4,9 +4,10 @@ module Interface
       extend ActiveSupport::Concern
 
       class_methods do
-        def cache_resource(expires_in: false)
+        def cache_resource(expires_in: false, tag: nil)
           @cache_resource = true
           @cache_expires_in = expires_in
+          @cache_tag = tag
         end
 
         def all(params = {}, base_scope = nil)
@@ -55,7 +56,7 @@ def build(params, base_scope = nil)
         private
 
         def caching_options
-          {cache: @cache_resource, cache_expires_in: @cache_expires_in}
+          {cache: @cache_resource, cache_expires_in: @cache_expires_in, cache_tag: @cache_tag}
         end
 
         def validate_request!(params)

lib/graphiti/resource_proxy.rb

@@ -2,14 +2,19 @@ module Graphiti
   class ResourceProxy
     include Enumerable
 
-    attr_reader :resource, :query, :scope, :payload, :cache_expires_in, :cache
+    attr_reader :resource, :query, :scope, :payload, :cache_expires_in, :cache, :cache_tag
 
-    def initialize(resource, scope, query,
+    def initialize(
+      resource,
+      scope,
+      query,
       payload: nil,
       single: false,
       raise_on_missing: false,
       cache: nil,
-      cache_expires_in: nil)
+      cache_expires_in: nil,
+      cache_tag: nil
+    )
 
       @resource = resource
       @scope = scope
@@ -19,6 +24,7 @@ def initialize(resource, scope, query,
       @raise_on_missing = raise_on_missing
       @cache = cache
       @cache_expires_in = cache_expires_in
+      @cache_tag = cache_tag
     end
 
     def cache?
@@ -207,12 +213,30 @@ def etag
       "W/#{ActiveSupport::Digest.hexdigest(cache_key_with_version.to_s)}"
     end
 
+    def resource_cache_tag
+      return unless @cache_tag.present? && @resource.respond_to?(@cache_tag)
+
+      @resource.try(@cache_tag)
+    end
+
     def cache_key
-      ActiveSupport::Cache.expand_cache_key([@scope.cache_key, @query.cache_key])
+      ActiveSupport::Cache.expand_cache_key(
+        [
+          @scope.cache_key,
+          @query.cache_key,
+          resource_cache_tag
+        ].compact_blank
+      )
     end
 
     def cache_key_with_version
-      ActiveSupport::Cache.expand_cache_key([@scope.cache_key_with_version, @query.cache_key])
+      ActiveSupport::Cache.expand_cache_key(
+        [
+          @scope.cache_key_with_version,
+          @query.cache_key,
+          resource_cache_tag
+        ].compact_blank
+      )
     end
 
     private

lib/graphiti/runner.rb

@@ -58,22 +58,29 @@ def jsonapi_render_options
 
     def proxy(base = nil, opts = {})
       base ||= jsonapi_resource.base_scope
-      scope_opts = opts.slice :sideload_parent_length,
+      scope_opts = opts.slice(
+        :sideload_parent_length,
         :default_paginate,
         :after_resolve,
         :sideload,
         :parent,
         :params,
         :bypass_required_filters
+      )
+
       scope = jsonapi_scope(base, scope_opts)
-      ResourceProxy.new jsonapi_resource,
+
+      ::Graphiti::ResourceProxy.new(
+        jsonapi_resource,
         scope,
         query,
         payload: deserialized_payload,
         single: opts[:single],
         raise_on_missing: opts[:raise_on_missing],
         cache: opts[:cache],
-        cache_expires_in: opts[:cache_expires_in]
+        cache_expires_in: opts[:cache_expires_in],
+        cache_tag: opts[:cache_tag]
+      )
     end
   end
 end

lib/graphiti/util/cache_debug.rb

@@ -12,7 +12,9 @@ def last_version
       end
 
       def name
-        "#{Graphiti.context[:object]&.request&.method} #{Graphiti.context[:object]&.request&.url}"
+        tag = proxy.resource_cache_tag
+
+        "#{::Graphiti.context[:object]&.request&.method} #{::Graphiti.context[:object]&.request&.url} #{tag}"
       end
 
       def key

spec/resource_proxy_spec.rb

@@ -14,13 +14,20 @@
     let(:query) { double(cache_key: "query-hash") }
     let(:scope) { double(cache_key: "scope-hash", cache_key_with_version: "scope-hash-123456") }
 
-    subject { described_class.new(resource, scope, query, **{}) }
+    subject { described_class.new(resource, scope, query, **{cache_tag: :cache_tag}) }
 
-    it "cache_key combines query and scope cache keys" do
+    it "cache_key combines query and scope cache keys if no tags are set" do
       cache_key = subject.cache_key
       expect(cache_key).to eq("scope-hash/query-hash")
     end
 
+    it "cache_key combines query, scope and tag cache keys if a tag is set" do
+      allow(resource).to receive(:cache_tag).and_return("tag_value")
+
+      cache_key = subject.cache_key
+      expect(cache_key).to eq("scope-hash/query-hash/tag_value")
+    end
+
     it "generates stable etag" do
       instance1 = described_class.new(resource, scope, query, **{})
       instance2 = described_class.new(resource, scope, query, **{})