diff options
Diffstat (limited to 'pkg/safemem/seq_test.go')
| -rw-r--r-- | pkg/safemem/seq_test.go | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/pkg/safemem/seq_test.go b/pkg/safemem/seq_test.go new file mode 100644 index 000000000..de34005e9 --- /dev/null +++ b/pkg/safemem/seq_test.go @@ -0,0 +1,217 @@ +// Copyright 2018 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package safemem + +import ( + "bytes" + "reflect" + "testing" +) + +func TestBlockSeqOfEmptyBlock(t *testing.T) { + bs := BlockSeqOf(Block{}) + if !bs.IsEmpty() { + t.Errorf("BlockSeqOf(Block{}).IsEmpty(): got false, wanted true; BlockSeq is %v", bs) + } +} + +func TestBlockSeqOfNonemptyBlock(t *testing.T) { + b := BlockFromSafeSlice(make([]byte, 1)) + bs := BlockSeqOf(b) + if bs.IsEmpty() { + t.Fatalf("BlockSeqOf(non-empty Block).IsEmpty(): got true, wanted false; BlockSeq is %v", bs) + } + if head := bs.Head(); head != b { + t.Fatalf("BlockSeqOf(non-empty Block).Head(): got %v, wanted %v", head, b) + } + if tail := bs.Tail(); !tail.IsEmpty() { + t.Fatalf("BlockSeqOf(non-empty Block).Tail().IsEmpty(): got false, wanted true: tail is %v", tail) + } +} + +type blockSeqTest struct { + desc string + + pieces []string + haveOffset bool + offset uint64 + haveLimit bool + limit uint64 + + want string +} + +func (t blockSeqTest) NonEmptyByteSlices() [][]byte { + // t is a value, so we can mutate it freely. + slices := make([][]byte, 0, len(t.pieces)) + for _, str := range t.pieces { + if t.haveOffset { + strOff := t.offset + if strOff > uint64(len(str)) { + strOff = uint64(len(str)) + } + str = str[strOff:] + t.offset -= strOff + } + if t.haveLimit { + strLim := t.limit + if strLim > uint64(len(str)) { + strLim = uint64(len(str)) + } + str = str[:strLim] + t.limit -= strLim + } + if len(str) != 0 { + slices = append(slices, []byte(str)) + } + } + return slices +} + +func (t blockSeqTest) BlockSeq() BlockSeq { + blocks := make([]Block, 0, len(t.pieces)) + for _, str := range t.pieces { + blocks = append(blocks, BlockFromSafeSlice([]byte(str))) + } + bs := BlockSeqFromSlice(blocks) + if t.haveOffset { + bs = bs.DropFirst64(t.offset) + } + if t.haveLimit { + bs = bs.TakeFirst64(t.limit) + } + return bs +} + +var blockSeqTests = []blockSeqTest{ + { + desc: "Empty sequence", + }, + { + desc: "Sequence of length 1", + pieces: []string{"foobar"}, + want: "foobar", + }, + { + desc: "Sequence of length 2", + pieces: []string{"foo", "bar"}, + want: "foobar", + }, + { + desc: "Empty Blocks", + pieces: []string{"", "foo", "", "", "bar", ""}, + want: "foobar", + }, + { + desc: "Sequence with non-zero offset", + pieces: []string{"foo", "bar"}, + haveOffset: true, + offset: 2, + want: "obar", + }, + { + desc: "Sequence with non-maximal limit", + pieces: []string{"foo", "bar"}, + haveLimit: true, + limit: 5, + want: "fooba", + }, + { + desc: "Sequence with offset and limit", + pieces: []string{"foo", "bar"}, + haveOffset: true, + offset: 2, + haveLimit: true, + limit: 3, + want: "oba", + }, +} + +func TestBlockSeqNumBytes(t *testing.T) { + for _, test := range blockSeqTests { + t.Run(test.desc, func(t *testing.T) { + if got, want := test.BlockSeq().NumBytes(), uint64(len(test.want)); got != want { + t.Errorf("NumBytes: got %d, wanted %d", got, want) + } + }) + } +} + +func TestBlockSeqIterBlocks(t *testing.T) { + // Tests BlockSeq iteration using Head/Tail. + for _, test := range blockSeqTests { + t.Run(test.desc, func(t *testing.T) { + srcs := test.BlockSeq() + // "Note that a non-nil empty slice and a nil slice ... are not + // deeply equal." - reflect + slices := make([][]byte, 0, 0) + for !srcs.IsEmpty() { + src := srcs.Head() + slices = append(slices, src.ToSlice()) + nextSrcs := srcs.Tail() + if got, want := nextSrcs.NumBytes(), srcs.NumBytes()-uint64(src.Len()); got != want { + t.Fatalf("%v.Tail(): got %v (%d bytes), wanted %d bytes", srcs, nextSrcs, got, want) + } + srcs = nextSrcs + } + if wantSlices := test.NonEmptyByteSlices(); !reflect.DeepEqual(slices, wantSlices) { + t.Errorf("Accumulated slices: got %v, wanted %v", slices, wantSlices) + } + }) + } +} + +func TestBlockSeqIterBytes(t *testing.T) { + // Tests BlockSeq iteration using Head/DropFirst. + for _, test := range blockSeqTests { + t.Run(test.desc, func(t *testing.T) { + srcs := test.BlockSeq() + var dst bytes.Buffer + for !srcs.IsEmpty() { + src := srcs.Head() + var b [1]byte + n, err := Copy(BlockFromSafeSlice(b[:]), src) + if n != 1 || err != nil { + t.Fatalf("Copy: got (%v, %v), wanted (1, nil)", n, err) + } + dst.WriteByte(b[0]) + nextSrcs := srcs.DropFirst(1) + if got, want := nextSrcs.NumBytes(), srcs.NumBytes()-1; got != want { + t.Fatalf("%v.DropFirst(1): got %v (%d bytes), wanted %d bytes", srcs, nextSrcs, got, want) + } + srcs = nextSrcs + } + if got := string(dst.Bytes()); got != test.want { + t.Errorf("Copied string: got %q, wanted %q", got, test.want) + } + }) + } +} + +func TestBlockSeqDropBeyondLimit(t *testing.T) { + blocks := []Block{BlockFromSafeSlice([]byte("123")), BlockFromSafeSlice([]byte("4"))} + bs := BlockSeqFromSlice(blocks) + if got, want := bs.NumBytes(), uint64(4); got != want { + t.Errorf("%v.NumBytes(): got %d, wanted %d", bs, got, want) + } + bs = bs.TakeFirst(1) + if got, want := bs.NumBytes(), uint64(1); got != want { + t.Errorf("%v.NumBytes(): got %d, wanted %d", bs, got, want) + } + bs = bs.DropFirst(2) + if got, want := bs.NumBytes(), uint64(0); got != want { + t.Errorf("%v.NumBytes(): got %d, wanted %d", bs, got, want) + } +} |