Migrate Gitlab::Git::Wiki#file to Gitalyfeature/migrate-find-wiki-file-to-gitaly

Closes gitaly#689

3 files changed, 65 insertions, 5 deletions

diff --git a/lib/gitlab/git/wiki.rb b/lib/gitlab/git/wiki.rb
index 549d22adde5..45362ac438b 100644
--- a/lib/gitlab/git/wiki.rb
+++ b/lib/gitlab/git/wiki.rb
@@ -68,11 +68,13 @@ module Gitlab
       end
 
       def file(name, version)
-        version ||= self.class.default_ref
-        gollum_file = gollum_wiki.file(name, version)
-        return unless gollum_file
-
-        Gitlab::Git::WikiFile.new(gollum_file)
+        @repository.gitaly_migrate(:wiki_find_file) do |is_enabled|
+          if is_enabled
+            gitaly_find_file(name, version)
+          else
+            gollum_find_file(name, version)
+          end
+        end
       end
 
       def page_versions(page_path)
@@ -156,6 +158,14 @@ module Gitlab
         new_page(gollum_page)
       end
 
+      def gollum_find_file(name, version)
+        version ||= self.class.default_ref
+        gollum_file = gollum_wiki.file(name, version)
+        return unless gollum_file
+
+        Gitlab::Git::WikiFile.new(gollum_file)
+      end
+
       def gitaly_write_page(name, format, content, commit_details)
         gitaly_wiki_client.write_page(name, format, content, commit_details)
       end
@@ -170,6 +180,13 @@ module Gitlab
 
         Gitlab::Git::WikiPage.new(wiki_page, version)
       end
+
+      def gitaly_find_file(name, version)
+        wiki_file = gitaly_wiki_client.find_file(name, version)
+        return unless wiki_file
+
+        Gitlab::Git::WikiFile.new(wiki_file)
+      end
     end
   end
 end
diff --git a/lib/gitlab/gitaly_client/wiki_file.rb b/lib/gitlab/gitaly_client/wiki_file.rb
new file mode 100644
index 00000000000..a2e415864e6
--- /dev/null
+++ b/lib/gitlab/gitaly_client/wiki_file.rb
@@ -0,0 +1,17 @@
+module Gitlab
+  module GitalyClient
+    class WikiFile
+      FIELDS = %i(name mime_type path raw_data).freeze
+
+      attr_accessor(*FIELDS)
+
+      def initialize(params)
+        params = params.with_indifferent_access
+
+        FIELDS.each do |field|
+          instance_variable_set("@#{field}", params[field])
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/gitaly_client/wiki_service.rb b/lib/gitlab/gitaly_client/wiki_service.rb
index 5d7930f5ff9..15f0f30d303 100644
--- a/lib/gitlab/gitaly_client/wiki_service.rb
+++ b/lib/gitlab/gitaly_client/wiki_service.rb
@@ -80,6 +80,32 @@ module Gitlab
         [wiki_page, version]
       end
 
+      def find_file(name, revision)
+        request = Gitaly::WikiFindFileRequest.new(
+          repository: @gitaly_repo,
+          name: GitalyClient.encode(name),
+          revision: GitalyClient.encode(revision)
+        )
+
+        response = GitalyClient.call(@repository.storage, :wiki_service, :wiki_find_file, request)
+        wiki_file = nil
+
+        response.each do |message|
+          next unless message.name.present?
+
+          if wiki_file
+            wiki_file.raw_data << message.raw_data
+          else
+            wiki_file = GitalyClient::WikiFile.new(message.to_h)
+            # All gRPC strings in a response are frozen, so we get
+            # an unfrozen version here so appending in the else clause below doesn't blow up.
+            wiki_file.raw_data = wiki_file.raw_data.dup
+          end
+        end
+
+        wiki_file
+      end
+
       private
 
       def gitaly_commit_details(commit_details)