Merge branch 'cache-refactor' into 'master'

Cache `#can_be_resolved_in_ui?` git operations

Closes gitaly#1051

See merge request gitlab-org/gitlab-ce!17589

2 files changed, 3 insertions, 81 deletions

diff --git a/app/models/repository.rb b/app/models/repository.rb
index 386fd0b1c9a..42f1ac43e29 100644
--- a/app/models/repository.rb
+++ b/app/models/repository.rb
@@ -16,6 +16,7 @@ class Repository
   ].freeze
 
   include Gitlab::ShellAdapter
+  include Gitlab::RepositoryCacheAdapter
 
   attr_accessor :full_path, :disk_path, :project, :is_wiki
 
@@ -57,22 +58,6 @@ class Repository
     merge_request_template: :merge_request_template_names
   }.freeze
 
-  # Wraps around the given method and caches its output in Redis and an instance
-  # variable.
-  #
-  # This only works for methods that do not take any arguments.
-  def self.cache_method(name, fallback: nil, memoize_only: false)
-    original = :"_uncached_#{name}"
-
-    alias_method(original, name)
-
-    define_method(name) do
-      cache_method_output(name, fallback: fallback, memoize_only: memoize_only) do
-        __send__(original) # rubocop:disable GitlabSecurity/PublicSend
-      end
-    end
-  end
-
   def initialize(full_path, project, disk_path: nil, is_wiki: false)
     @full_path = full_path
     @disk_path = disk_path || full_path
@@ -302,17 +287,6 @@ class Repository
     expire_method_caches(CACHED_METHODS)
   end
 
-  # Expires the caches of a specific set of methods
-  def expire_method_caches(methods)
-    methods.each do |key|
-      cache.expire(key)
-
-      ivar = cache_instance_variable_name(key)
-
-      remove_instance_variable(ivar) if instance_variable_defined?(ivar)
-    end
-  end
-
   def expire_avatar_cache
     expire_method_caches(%i(avatar))
   end
@@ -924,49 +898,6 @@ class Repository
     end
   end
 
-  # Caches the supplied block both in a cache and in an instance variable.
-  #
-  # The cache key and instance variable are named the same way as the value of
-  # the `key` argument.
-  #
-  # This method will return `nil` if the corresponding instance variable is also
-  # set to `nil`. This ensures we don't keep yielding the block when it returns
-  # `nil`.
-  #
-  # key - The name of the key to cache the data in.
-  # fallback - A value to fall back to in the event of a Git error.
-  def cache_method_output(key, fallback: nil, memoize_only: false, &block)
-    ivar = cache_instance_variable_name(key)
-
-    if instance_variable_defined?(ivar)
-      instance_variable_get(ivar)
-    else
-      # If the repository doesn't exist and a fallback was specified we return
-      # that value inmediately. This saves us Rugged/gRPC invocations.
-      return fallback unless fallback.nil? || exists?
-
-      begin
-        value =
-          if memoize_only
-            yield
-          else
-            cache.fetch(key, &block)
-          end
-
-        instance_variable_set(ivar, value)
-      rescue Gitlab::Git::Repository::NoRepository
-        # Even if the above `#exists?` check passes these errors might still
-        # occur (for example because of a non-existing HEAD). We want to
-        # gracefully handle this and not cache anything
-        fallback
-      end
-    end
-  end
-
-  def cache_instance_variable_name(key)
-    :"@#{key.to_s.tr('?!', '')}"
-  end
-
   def file_on_head(type)
     if head = tree(:head)
       head.blobs.find do |blob|
@@ -1021,8 +952,7 @@ class Repository
   end
 
   def cache
-    # TODO: should we use UUIDs here? We could move repositories without clearing this cache
-    @cache ||= RepositoryCache.new(full_path, @project.id)
+    @cache ||= Gitlab::RepositoryCache.new(self)
   end
 
   def tags_sorted_by_committed_date
diff --git a/app/services/merge_requests/conflicts/list_service.rb b/app/services/merge_requests/conflicts/list_service.rb
index ca9a33678e4..72cbc49adb2 100644
--- a/app/services/merge_requests/conflicts/list_service.rb
+++ b/app/services/merge_requests/conflicts/list_service.rb
@@ -17,15 +17,7 @@ module MergeRequests
         return @conflicts_can_be_resolved_in_ui = false unless merge_request.has_complete_diff_refs?
         return @conflicts_can_be_resolved_in_ui = false if merge_request.branch_missing?
 
-        begin
-          # Try to parse each conflict. If the MR's mergeable status hasn't been
-          # updated, ensure that we don't say there are conflicts to resolve
-          # when there are no conflict files.
-          conflicts.files.each(&:lines)
-          @conflicts_can_be_resolved_in_ui = conflicts.files.length > 0
-        rescue Gitlab::Git::CommandError, Gitlab::Git::Conflict::Parser::UnresolvableError, Gitlab::Git::Conflict::Resolver::ConflictSideMissing
-          @conflicts_can_be_resolved_in_ui = false
-        end
+        @conflicts_can_be_resolved_in_ui = conflicts.can_be_resolved_in_ui?
       end
 
       def conflicts