Merge branch 'fix-lazy-blobs-requesting-all-previous-blobs' into 'master'

Ensure that we only request blobs in one batch

Closes #60829

See merge request gitlab-org/gitlab-ce!27625

changelogs/unreleased/fix-lazy-blobs-requesting-all-previous-blobs.yml

+---
+title: Fix Blob.lazy always loading all previously-requested blobs when a new request
+  is made
+merge_request:
+author:
+type: performance

lib/gitlab/gitaly_client/blob_service.rb

@@ -55,13 +55,13 @@ module Gitlab
       def get_blobs(revision_paths, limit = -1)
         return [] if revision_paths.empty?
 
-        revision_paths.map! do |rev, path|
+        request_revision_paths = revision_paths.map do |rev, path|
           Gitaly::GetBlobsRequest::RevisionPath.new(revision: rev, path: encode_binary(path))
         end
 
         request = Gitaly::GetBlobsRequest.new(
           repository: @gitaly_repo,
-          revision_paths: revision_paths,
+          revision_paths: request_revision_paths,
           limit: limit
         )
 

spec/models/blob_spec.rb

@@ -43,6 +43,21 @@ describe Blob do
       changelog.id
       contributing.id
     end
+
+    it 'does not include blobs from previous requests in later requests' do
+      changelog = described_class.lazy(project, commit_id, 'CHANGELOG')
+      contributing = described_class.lazy(same_project, commit_id, 'CONTRIBUTING.md')
+
+      # Access property so the values are loaded
+      changelog.id
+      contributing.id
+
+      readme = described_class.lazy(project, commit_id, 'README.md')
+
+      expect(project.repository).to receive(:blobs_at).with([[commit_id, 'README.md']]).once.and_call_original
+
+      readme.id
+    end
   end
 
   describe '#data' do