feat: add DeleteObjects

Add DeleteObjects, which allows the caller to delete one or more data
objects that match a DescriptorSelectorFunc.

pkg/sif/delete.go

@@ -74,15 +74,29 @@ func OptDeleteWithTime(t time.Time) DeleteOpt {
 	}
 }
 
-// DeleteObject deletes the data object with id, according to opts.
+// DeleteObject deletes the data object with id, according to opts. If no matching descriptor is
+// found, an error wrapping ErrObjectNotFound is returned.
 //
-// To zero the data region of the deleted object, use OptDeleteZero. To compact the file following
-// object deletion, use OptDeleteCompact.
+// To zero the data region of the deleted object, use OptDeleteZero. To remove unused space at the
+// end of the FileImage following object deletion, use OptDeleteCompact.
 //
 // By default, the image modification time is set to the current time for non-deterministic images,
 // and unset otherwise. To override this, consider using OptDeleteDeterministic or
 // OptDeleteWithTime.
 func (f *FileImage) DeleteObject(id uint32, opts ...DeleteOpt) error {
+	return f.DeleteObjects(WithID(id), opts...)
+}
+
+// DeleteObjects deletes the data objects selected by fn, according to opts. If no descriptors are
+// selected by fns, an error wrapping ErrObjectNotFound is returned.
+//
+// To zero the data region of the deleted object, use OptDeleteZero. To remove unused space at the
+// end of the FileImage following object deletion, use OptDeleteCompact.
+//
+// By default, the image modification time is set to the current time for non-deterministic images,
+// and unset otherwise. To override this, consider using OptDeleteDeterministic or
+// OptDeleteWithTime.
+func (f *FileImage) DeleteObjects(fn DescriptorSelectorFunc, opts ...DeleteOpt) error {
 	do := deleteOpts{}
 
 	if !f.isDeterministic() {
@@ -95,29 +109,39 @@ func (f *FileImage) DeleteObject(id uint32, opts ...DeleteOpt) error {
 		}
 	}
 
-	d, err := f.getDescriptor(WithID(id))
-	if err != nil {
-		return fmt.Errorf("%w", err)
-	}
+	var selected bool
 
-	if do.zero {
-		if err := f.zero(d); err != nil {
-			return fmt.Errorf("%w", err)
+	if err := f.withDescriptors(fn, func(d *rawDescriptor) error {
+		selected = true
+
+		if do.zero {
+			if err := f.zero(d); err != nil {
+				return fmt.Errorf("%w", err)
+			}
 		}
-	}
 
-	f.h.DescriptorsFree++
-	f.h.ModifiedAt = do.t.Unix()
+		f.h.DescriptorsFree++
+
+		// If we remove the primary partition, set the global header Arch field to HdrArchUnknown
+		// to indicate that the SIF file doesn't include a primary partition and no dependency
+		// on any architecture exists.
+		if d.isPartitionOfType(PartPrimSys) {
+			f.h.Arch = hdrArchUnknown
+		}
+
+		// Reset rawDescripter with empty struct
+		*d = rawDescriptor{}
 
-	// If we remove the primary partition, set the global header Arch field to HdrArchUnknown
-	// to indicate that the SIF file doesn't include a primary partition and no dependency
-	// on any architecture exists.
-	if d.isPartitionOfType(PartPrimSys) {
-		f.h.Arch = hdrArchUnknown
+		return nil
+	}); err != nil {
+		return fmt.Errorf("%w", err)
 	}
 
-	// Reset rawDescripter with empty struct
-	*d = rawDescriptor{}
+	if !selected {
+		return fmt.Errorf("%w", ErrObjectNotFound)
+	}
+
+	f.h.ModifiedAt = do.t.Unix()
 
 	if do.compact {
 		f.h.DataSize = f.calculatedDataSize()

pkg/sif/delete_test.go

@@ -195,6 +195,99 @@ func TestDeleteObject(t *testing.T) {
 	}
 }
 
+func TestDeleteObjects(t *testing.T) {
+	tests := []struct {
+		name       string
+		createOpts []CreateOpt
+		fn         DescriptorSelectorFunc
+		opts       []DeleteOpt
+		wantErr    error
+	}{
+		{
+			name: "ErrObjectNotFound",
+			createOpts: []CreateOpt{
+				OptCreateDeterministic(),
+			},
+			fn:      WithID(1),
+			wantErr: ErrObjectNotFound,
+		},
+		{
+			name: "NilSelectFunc",
+			createOpts: []CreateOpt{
+				OptCreateDeterministic(),
+				OptCreateWithDescriptors(
+					getDescriptorInput(t, DataGeneric, []byte{0xfa, 0xce}),
+					getDescriptorInput(t, DataGeneric, []byte{0xfe, 0xed}),
+				),
+			},
+			fn:      nil,
+			wantErr: errNilSelectFunc,
+		},
+		{
+			name: "DataType",
+			createOpts: []CreateOpt{
+				OptCreateDeterministic(),
+				OptCreateWithDescriptors(
+					getDescriptorInput(t, DataGeneric, []byte{0xfa, 0xce}),
+					getDescriptorInput(t, DataGeneric, []byte{0xfe, 0xed}),
+				),
+			},
+			fn: WithDataType(DataGeneric),
+		},
+		{
+			name: "DataTypeCompact",
+			createOpts: []CreateOpt{
+				OptCreateDeterministic(),
+				OptCreateWithDescriptors(
+					getDescriptorInput(t, DataGeneric, []byte{0xfa, 0xce}),
+					getDescriptorInput(t, DataGeneric, []byte{0xfe, 0xed}),
+				),
+			},
+			fn: WithDataType(DataGeneric),
+			opts: []DeleteOpt{
+				OptDeleteCompact(true),
+			},
+		},
+		{
+			name: "PrimaryPartitionCompact",
+			createOpts: []CreateOpt{
+				OptCreateDeterministic(),
+				OptCreateWithDescriptors(
+					getDescriptorInput(t, DataPartition, []byte{0xfa, 0xce},
+						OptPartitionMetadata(FsSquash, PartPrimSys, "386"),
+					),
+				),
+			},
+			fn: WithPartitionType(PartPrimSys),
+			opts: []DeleteOpt{
+				OptDeleteCompact(true),
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var b Buffer
+
+			f, err := CreateContainer(&b, tt.createOpts...)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if got, want := f.DeleteObjects(tt.fn, tt.opts...), tt.wantErr; !errors.Is(got, want) {
+				t.Errorf("got error %v, want %v", got, want)
+			}
+
+			if err := f.UnloadContainer(); err != nil {
+				t.Error(err)
+			}
+
+			g := goldie.New(t, goldie.WithTestNameForDir(true))
+			g.Assert(t, tt.name, b.Bytes())
+		})
+	}
+}
+
 func TestDeleteObjectAndAddObject(t *testing.T) {
 	tests := []struct {
 		name string

pkg/sif/select.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2021-2023, Sylabs Inc. All rights reserved.
+// Copyright (c) 2021-2024, Sylabs Inc. All rights reserved.
 // This software is licensed under a 3-clause BSD license. Please consult the
 // LICENSE file distributed with the sources of this project regarding your
 // rights to use or distribute this software.
@@ -184,10 +184,16 @@ func multiSelectorFunc(fns ...DescriptorSelectorFunc) DescriptorSelectorFunc {
 	}
 }
 
+var errNilSelectFunc = errors.New("descriptor selector func must not be nil")
+
 // withDescriptors calls onMatchFn with each in-use descriptor in f for which selectFn returns
 // true. If selectFn or onMatchFn return a non-nil error, the iteration halts, and the error is
 // returned to the caller.
 func (f *FileImage) withDescriptors(selectFn DescriptorSelectorFunc, onMatchFn func(*rawDescriptor) error) error {
+	if selectFn == nil {
+		return errNilSelectFunc
+	}
+
 	for i, d := range f.rds {
 		if !d.Used {
 			continue