Finished segment with its tests.

internal/log/segment_test.go

@@ -0,0 +1,60 @@
+package log
+
+import (
+	"io"
+	"io/ioutil"
+	"os"
+	"testing"
+
+	api "github.com/AYM1607/proglog/api/v1"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSegment(t *testing.T) {
+	dir, _ := ioutil.TempDir("", "segment-test")
+	defer os.RemoveAll(dir)
+
+	want := &api.Record{Value: []byte("hello world")}
+
+	c := Config{}
+	c.Segment.MaxIndexBytes = entWidth * 3
+	c.Segment.MaxStoreBytes = 1024
+
+	s, err := newSegment(dir, 16, c)
+	require.NoError(t, err, "The segment is created successfully")
+	require.Equal(t, uint64(16), s.nextOffset, "Next offset should be equal to base offset for new segments.")
+
+	for i := uint64(0); i < 3; i++ {
+		off, err := s.Append(want)
+		require.NoError(t, err, "Record should be appended successfully.")
+		require.Equal(t, off, 16+i, "The offsets should be increase by 1 with respect to the base offset.")
+
+		got, err := s.Read(off)
+		require.NoError(t, err, "Existing records should be read successfully.")
+		require.Equal(t, want.Value, got.Value, "Record's read data should be the same as the written one.")
+	}
+
+	_, err = s.Append(want)
+	require.Equal(t, io.EOF, err, "Appends should fail if the segment is maxed.")
+
+	require.True(t, s.IsMaxed(), "IsMaxed should return true when the segment's index is maxed.")
+
+	// Create a new segment from the same files with a different configuration.
+	c.Segment.MaxIndexBytes = 1024
+	// The length of the record's value is not the same as the byte size of the
+	// marshalled data which includes other fields. By setting this as the limit though,
+	// we assure that the store will be maxed with only 3 records.
+	c.Segment.MaxStoreBytes = uint64(len(want.Value) * 3)
+
+	s, err = newSegment(dir, 16, c)
+	require.NoError(t, err, "Segment should be created successfully from existing files.")
+	require.True(t, s.IsMaxed(), "IsMaxed should return true when the segment's store is maxed.")
+
+	err = s.Remove()
+	require.NoError(t, err, "Segment should be able to remove itself.")
+
+	s, err = newSegment(dir, 16, c)
+	require.NoError(t, err, "Segment should create the necessary files after removed.")
+	require.False(t, s.IsMaxed(), "Segment should not be maxed if new and config's limits are non-zero.")
+
+}