github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/pkg/tcpip/transport/tcp/segment_test.go (about)

     1  // Copyright 2021 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package tcp
    16  
    17  import (
    18  	"testing"
    19  
    20  	"github.com/google/go-cmp/cmp"
    21  	"github.com/SagerNet/gvisor/pkg/tcpip/buffer"
    22  	"github.com/SagerNet/gvisor/pkg/tcpip/faketime"
    23  	"github.com/SagerNet/gvisor/pkg/tcpip/stack"
    24  )
    25  
    26  type segmentSizeWants struct {
    27  	DataSize   int
    28  	SegMemSize int
    29  }
    30  
    31  func checkSegmentSize(t *testing.T, name string, seg *segment, want segmentSizeWants) {
    32  	t.Helper()
    33  	got := segmentSizeWants{
    34  		DataSize:   seg.data.Size(),
    35  		SegMemSize: seg.segMemSize(),
    36  	}
    37  	if diff := cmp.Diff(got, want); diff != "" {
    38  		t.Errorf("%s differs (-want +got):\n%s", name, diff)
    39  	}
    40  }
    41  
    42  func TestSegmentMerge(t *testing.T) {
    43  	var clock faketime.NullClock
    44  	id := stack.TransportEndpointID{}
    45  	seg1 := newOutgoingSegment(id, &clock, buffer.NewView(10))
    46  	defer seg1.decRef()
    47  	seg2 := newOutgoingSegment(id, &clock, buffer.NewView(20))
    48  	defer seg2.decRef()
    49  
    50  	checkSegmentSize(t, "seg1", seg1, segmentSizeWants{
    51  		DataSize:   10,
    52  		SegMemSize: SegSize + 10,
    53  	})
    54  	checkSegmentSize(t, "seg2", seg2, segmentSizeWants{
    55  		DataSize:   20,
    56  		SegMemSize: SegSize + 20,
    57  	})
    58  
    59  	seg1.merge(seg2)
    60  
    61  	checkSegmentSize(t, "seg1", seg1, segmentSizeWants{
    62  		DataSize:   30,
    63  		SegMemSize: SegSize + 30,
    64  	})
    65  	checkSegmentSize(t, "seg2", seg2, segmentSizeWants{
    66  		DataSize:   0,
    67  		SegMemSize: SegSize,
    68  	})
    69  }