Remove in_memory and directory_path file pools

Remove the in_memory and directory_path file pools. These filepools are
better to replace with the block_device backed filepool which supports
sparse files and behaves better during circumstances with scarce
resources.

Author: meroton-benjamin

pkg/builder/file_pool_stats_build_executor_test.go

@@ -70,12 +70,29 @@ func TestFilePoolStatsBuildExecutorExample(t *testing.T) {
 		}
 	})
 
+	// Mock all the file operations performed in the execution request.
+	filePool := mock.NewMockFilePool(ctrl)
+	file1 := mock.NewMockFileReadWriter(ctrl)
+	file2 := mock.NewMockFileReadWriter(ctrl)
+
+	filePool.EXPECT().NewFile().Return(file1, nil)
+	file1.EXPECT().Truncate(int64(5)).Return(nil)
+	file1.EXPECT().Close().Return(nil)
+	filePool.EXPECT().NewFile().Return(file2, nil)
+	file2.EXPECT().WriteAt([]byte("Hello"), int64(100)).Return(5, nil)
+	file2.EXPECT().ReadAt(gomock.Any(), int64(98)).DoAndReturn(func(p []byte, offset int64) (int, error) {
+		copy(p, []byte("\x00\x00Hello\x00\x00\x00"))
+		return 7, io.EOF
+	})
+	file2.EXPECT().Truncate(int64(42)).Return(nil)
+	file2.EXPECT().Close().Return(nil)
+
 	// Perform the execution request.
 	executionStateUpdates := make(chan *remoteworker.CurrentState_Executing, 3)
 	buildExecutor := builder.NewFilePoolStatsBuildExecutor(baseBuildExecutor)
 	executeResponse := buildExecutor.Execute(
 		ctx,
-		filesystem.InMemoryFilePool,
+		filePool,
 		monitor,
 		digest.MustNewFunction("hello", remoteexecution.DigestFunction_MD5),
 		request,

pkg/filesystem/BUILD.bazel

@@ -6,10 +6,8 @@ go_library(
         "bitmap_sector_allocator.go",
         "block_device_backed_file_pool.go",
         "configuration.go",
-        "directory_backed_file_pool.go",
         "empty_file_pool.go",
         "file_pool.go",
-        "in_memory_file_pool.go",
         "lazy_directory.go",
         "metrics_file_pool.go",
         "quota_enforcing_file_pool.go",
@@ -34,9 +32,7 @@ go_test(
     srcs = [
         "bitmap_sector_allocator_test.go",
         "block_device_backed_file_pool_test.go",
-        "directory_backed_file_pool_test.go",
         "empty_file_pool_test.go",
-        "in_memory_file_pool_test.go",
         "lazy_directory_test.go",
         "quota_enforcing_file_pool_test.go",
     ],

pkg/filesystem/configuration.go

@@ -5,8 +5,6 @@ import (
 
 	pb "github.com/buildbarn/bb-remote-execution/pkg/proto/configuration/filesystem"
 	"github.com/buildbarn/bb-storage/pkg/blockdevice"
-	"github.com/buildbarn/bb-storage/pkg/filesystem"
-	"github.com/buildbarn/bb-storage/pkg/filesystem/path"
 	"github.com/buildbarn/bb-storage/pkg/util"
 
 	"google.golang.org/grpc/codes"
@@ -25,18 +23,6 @@ func NewFilePoolFromConfiguration(configuration *pb.FilePoolConfiguration) (File
 
 	var filePool FilePool
 	switch backend := configuration.Backend.(type) {
-	case *pb.FilePoolConfiguration_InMemory:
-		filePool = InMemoryFilePool
-	case *pb.FilePoolConfiguration_DirectoryPath:
-		directory, err := filesystem.NewLocalDirectory(path.LocalFormat.NewParser(backend.DirectoryPath))
-		if err != nil {
-			return nil, util.StatusWrapf(err, "Failed to open directory %#v", backend.DirectoryPath)
-		}
-		if err := directory.RemoveAllChildren(); err != nil {
-			directory.Close()
-			return nil, util.StatusWrapf(err, "Failed to empty out directory %#v", backend.DirectoryPath)
-		}
-		filePool = NewDirectoryBackedFilePool(directory)
 	case *pb.FilePoolConfiguration_BlockDevice:
 		blockDevice, sectorSizeBytes, sectorCount, err := blockdevice.NewBlockDeviceFromConfiguration(backend.BlockDevice, true)
 		if err != nil {