Add support for deltas_only under Gitaly

Closes gitaly#199

2 files changed, 45 insertions, 29 deletions

diff --git a/lib/gitlab/git/diff.rb b/lib/gitlab/git/diff.rb
index 019be151353..31d1b66b4f7 100644
--- a/lib/gitlab/git/diff.rb
+++ b/lib/gitlab/git/diff.rb
@@ -183,6 +183,8 @@ module Gitlab
         when Gitaly::CommitDiffResponse
           init_from_gitaly(raw_diff)
           prune_diff_if_eligible(collapse)
+        when Gitaly::CommitDelta
+          init_from_gitaly(raw_diff)
         when nil
           raise "Nil as raw diff passed"
         else
@@ -278,15 +280,15 @@ module Gitlab
         end
       end
 
-      def init_from_gitaly(diff_msg)
-        @diff = diff_msg.raw_chunks.join
-        @new_path = encode!(diff_msg.to_path.dup)
-        @old_path = encode!(diff_msg.from_path.dup)
-        @a_mode = diff_msg.old_mode.to_s(8)
-        @b_mode = diff_msg.new_mode.to_s(8)
-        @new_file = diff_msg.from_id == BLANK_SHA
-        @renamed_file = diff_msg.from_path != diff_msg.to_path
-        @deleted_file = diff_msg.to_id == BLANK_SHA
+      def init_from_gitaly(msg)
+        @diff = msg.raw_chunks.join if msg.respond_to?(:raw_chunks)
+        @new_path = encode!(msg.to_path.dup)
+        @old_path = encode!(msg.from_path.dup)
+        @a_mode = msg.old_mode.to_s(8)
+        @b_mode = msg.new_mode.to_s(8)
+        @new_file = msg.from_id == BLANK_SHA
+        @renamed_file = msg.from_path != msg.to_path
+        @deleted_file = msg.to_id == BLANK_SHA
       end
 
       def prune_diff_if_eligible(collapse = false)
diff --git a/lib/gitlab/gitaly_client/commit.rb b/lib/gitlab/gitaly_client/commit.rb
index 8e9323b05e1..15c57420fb2 100644
--- a/lib/gitlab/gitaly_client/commit.rb
+++ b/lib/gitlab/gitaly_client/commit.rb
@@ -5,41 +5,55 @@ module Gitlab
       # See http://stackoverflow.com/a/40884093/1856239 and https://github.com/git/git/blob/3ad8b5bf26362ac67c9020bf8c30eee54a84f56d/cache.h#L1011-L1012
       EMPTY_TREE_ID = '4b825dc642cb6eb9a060e54bf8d69288fbee4904'.freeze
 
-      attr_accessor :stub
-
       def initialize(repository)
         @gitaly_repo = repository.gitaly_repository
-        @stub = Gitaly::Commit::Stub.new(nil, nil, channel_override: repository.gitaly_channel)
+        @repository = repository
       end
 
       def is_ancestor(ancestor_id, child_id)
+        stub = Gitaly::Commit::Stub.new(nil, nil, channel_override: @repository.gitaly_channel)
         request = Gitaly::CommitIsAncestorRequest.new(
           repository: @gitaly_repo,
           ancestor_id: ancestor_id,
           child_id: child_id
         )
 
-        @stub.commit_is_ancestor(request).value
+        stub.commit_is_ancestor(request).value
+      end
+
+      def diff_from_parent(commit, options = {})
+        request_params = commit_diff_request_params(commit, options)
+        request_params[:ignore_whitespace_change] = options.fetch(:ignore_whitespace_change, false)
+
+        response = diff_service_stub.commit_diff(Gitaly::CommitDiffRequest.new(request_params))
+        Gitlab::Git::DiffCollection.new(response, options)
       end
 
-      class << self
-        def diff_from_parent(commit, options = {})
-          repository = commit.project.repository
-          gitaly_repo = repository.gitaly_repository
-          stub = Gitaly::Diff::Stub.new(nil, nil, channel_override: repository.gitaly_channel)
-          parent = commit.parents[0]
-          parent_id = parent ? parent.id : EMPTY_TREE_ID
-          request = Gitaly::CommitDiffRequest.new(
-            repository: gitaly_repo,
-            left_commit_id: parent_id,
-            right_commit_id: commit.id,
-            ignore_whitespace_change: options.fetch(:ignore_whitespace_change, false),
-            paths: options.fetch(:paths, [])
-          )
-
-          Gitlab::Git::DiffCollection.new(stub.commit_diff(request), options)
+      def commit_deltas(commit)
+        request_params = commit_diff_request_params(commit)
+
+        response = diff_service_stub.commit_delta(Gitaly::CommitDeltaRequest.new(request_params))
+        response.flat_map do |msg|
+          msg.deltas.map { |d| Gitlab::Git::Diff.new(d) }
         end
       end
+
+      private
+
+      def commit_diff_request_params(commit, options = {})
+        parent_id = commit.parents[0]&.id || EMPTY_TREE_ID
+
+        {
+          repository: @gitaly_repo,
+          left_commit_id: parent_id,
+          right_commit_id: commit.id,
+          paths: options.fetch(:paths, [])
+        }
+      end
+
+      def diff_service_stub
+        Gitaly::Diff::Stub.new(nil, nil, channel_override: @repository.gitaly_channel)
+      end
     end
   end
 end