Migrate Git::Blob.batch to Gitaly

Closes gitaly#985

Gemfile

@@ -410,7 +410,7 @@ group :ed25519 do
 end
 
 # Gitaly GRPC client
-gem 'gitaly-proto', '~> 0.83.0', require: 'gitaly'
+gem 'gitaly-proto', '~> 0.84.0', require: 'gitaly'
 # Locked until https://github.com/google/protobuf/issues/4210 is closed
 gem 'google-protobuf', '= 3.5.1'
 

Gemfile.lock

@@ -285,7 +285,7 @@ GEM
       po_to_json (>= 1.0.0)
       rails (>= 3.2.0)
     gherkin-ruby (0.3.2)
-    gitaly-proto (0.83.0)
+    gitaly-proto (0.84.0)
       google-protobuf (~> 3.1)
       grpc (~> 1.0)
     github-linguist (4.7.6)
@@ -1056,7 +1056,7 @@ DEPENDENCIES
   gettext (~> 3.2.2)
   gettext_i18n_rails (~> 1.8.0)
   gettext_i18n_rails_js (~> 1.2.0)
-  gitaly-proto (~> 0.83.0)
+  gitaly-proto (~> 0.84.0)
   github-linguist (~> 4.7.0)
   gitlab-flowdock-git-hook (~> 1.0.1)
   gitlab-markup (~> 1.6.2)

lib/gitlab/git/blob.rb

@@ -53,11 +53,7 @@ module Gitlab
         def batch(repository, blob_references, blob_size_limit: MAX_DATA_DISPLAY_SIZE)
           Gitlab::GitalyClient.migrate(:list_blobs_by_sha_path) do |is_enabled|
             if is_enabled
-              Gitlab::GitalyClient.allow_n_plus_1_calls do
-                blob_references.map do |sha, path|
-                  find_by_gitaly(repository, sha, path, limit: blob_size_limit)
-                end
-              end
+              repository.gitaly_blob_client.get_blobs(blob_references, blob_size_limit).to_a
             else
               blob_references.map do |sha, path|
                 find_by_rugged(repository, sha, path, limit: blob_size_limit)

lib/gitlab/gitaly_client/blob_service.rb

 module Gitlab
   module GitalyClient
     class BlobService
+      include Gitlab::EncodingHelper
+
       def initialize(repository)
         @gitaly_repo = repository.gitaly_repository
       end
@@ -54,6 +56,30 @@ module Gitlab
           end
         end
       end
+
+      def get_blobs(revision_paths, limit = -1)
+        return [] if revision_paths.empty?
+
+        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,
+          limit: limit
+        )
+
+        response = GitalyClient.call(
+          @gitaly_repo.storage_name,
+          :blob_service,
+          :get_blobs,
+          request,
+          timeout: GitalyClient.default_timeout
+        )
+
+        GitalyClient::BlobsStitcher.new(response)
+      end
     end
   end
 end

lib/gitlab/gitaly_client/blobs_stitcher.rb

+module Gitlab
+  module GitalyClient
+    class BlobsStitcher
+      include Enumerable
+
+      def initialize(rpc_response)
+        @rpc_response = rpc_response
+      end
+
+      def each
+        current_blob_data = nil
+
+        @rpc_response.each do |msg|
+          begin
+            if msg.oid.blank? && msg.data.blank?
+              next
+            elsif msg.oid.present?
+              yield new_blob(current_blob_data) if current_blob_data
+
+              current_blob_data = msg.to_h.slice(:oid, :path, :size, :revision, :mode)
+              current_blob_data[:data] = msg.data.dup
+            else
+              current_blob_data[:data] << msg.data
+            end
+          end
+        end
+
+        yield new_blob(current_blob_data) if current_blob_data
+      end
+
+      private
+
+      def new_blob(blob_data)
+        Gitlab::Git::Blob.new(
+          id: blob_data[:oid],
+          mode: blob_data[:mode].to_s(8),
+          name: File.basename(blob_data[:path]),
+          path: blob_data[:path],
+          size: blob_data[:size],
+          commit_id: blob_data[:revision],
+          data: blob_data[:data],
+          binary: Gitlab::Git::Blob.binary?(blob_data[:data])
+        )
+      end
+    end
+  end
+end

spec/lib/gitlab/git/blob_spec.rb

@@ -178,6 +178,7 @@ describe Gitlab::Git::Blob, seed_helper: true do
   end
 
   describe '.batch' do
+    shared_examples 'loading blobs in batch' do
       let(:blob_references) do
         [
           [SeedRepo::Commit::ID, "files/ruby/popen.rb"],
@@ -241,6 +242,15 @@ describe Gitlab::Git::Blob, seed_helper: true do
       end
     end
 
+    context 'when Gitaly list_blobs_by_sha_path feature is enabled' do
+      it_behaves_like 'loading blobs in batch'
+    end
+
+    context 'when Gitaly list_blobs_by_sha_path feature is disabled', :disable_gitaly do
+      it_behaves_like 'loading blobs in batch'
+    end
+  end
+
   describe '.batch_lfs_pointers' do
     let(:tree_object) { repository.rugged.rev_parse('master^{tree}') }
 

spec/lib/gitlab/gitaly_client/blobs_stitcher_spec.rb

+require 'spec_helper'
+
+describe Gitlab::GitalyClient::BlobsStitcher do
+  describe 'enumeration' do
+    it 'combines segregated blob messages together' do
+      messages = [
+        OpenStruct.new(oid: 'abcdef1', path: 'path/to/file', size: 1642, revision: 'f00ba7', mode: 0100644, data: "first-line\n"),
+        OpenStruct.new(oid: '', data: 'second-line'),
+        OpenStruct.new(oid: '', data: '', revision: 'f00ba7', path: 'path/to/non-existent/file'),
+        OpenStruct.new(oid: 'abcdef2', path: 'path/to/another-file', size: 2461, revision: 'f00ba8', mode: 0100644, data: "GIF87a\x90\x01".b)
+      ]
+
+      blobs = described_class.new(messages).to_a
+
+      expect(blobs.size).to be(2)
+
+      expect(blobs[0].id).to eq('abcdef1')
+      expect(blobs[0].mode).to eq('100644')
+      expect(blobs[0].name).to eq('file')
+      expect(blobs[0].path).to eq('path/to/file')
+      expect(blobs[0].size).to eq(1642)
+      expect(blobs[0].commit_id).to eq('f00ba7')
+      expect(blobs[0].data).to eq("first-line\nsecond-line")
+      expect(blobs[0].binary?).to be false
+
+      expect(blobs[1].id).to eq('abcdef2')
+      expect(blobs[1].mode).to eq('100644')
+      expect(blobs[1].name).to eq('another-file')
+      expect(blobs[1].path).to eq('path/to/another-file')
+      expect(blobs[1].size).to eq(2461)
+      expect(blobs[1].commit_id).to eq('f00ba8')
+      expect(blobs[1].data).to eq("GIF87a\x90\x01".b)
+      expect(blobs[1].binary?).to be true
+    end
+  end
+end