change overflow from map to slice

weed/storage/needle/compact_map_test.go

@@ -19,7 +19,7 @@ func TestIssue52(t *testing.T) {
 	}
 }
 
-func TestXYZ(t *testing.T) {
+func TestCompactMap(t *testing.T) {
 	m := NewCompactMap()
 	for i := uint32(0); i < 100*batch; i += 2 {
 		m.Set(NeedleId(i), Offset(i), i)
@@ -76,3 +76,64 @@ func TestXYZ(t *testing.T) {
 	}
 
 }
+
+func TestOverflow(t *testing.T) {
+	o := Overflow(make([]NeedleValue, 0))
+
+	o = o.setOverflowEntry(NeedleValue{Key: 1, Offset: 12, Size: 12})
+	o = o.setOverflowEntry(NeedleValue{Key: 2, Offset: 12, Size: 12})
+	o = o.setOverflowEntry(NeedleValue{Key: 3, Offset: 12, Size: 12})
+	o = o.setOverflowEntry(NeedleValue{Key: 4, Offset: 12, Size: 12})
+	o = o.setOverflowEntry(NeedleValue{Key: 5, Offset: 12, Size: 12})
+
+	if o[2].Key != 3 {
+		t.Fatalf("expecting o[2] has key 3: %+v", o[2].Key)
+	}
+
+	o = o.setOverflowEntry(NeedleValue{Key: 3, Offset: 24, Size: 24})
+
+	if o[2].Key != 3 {
+		t.Fatalf("expecting o[2] has key 3: %+v", o[2].Key)
+	}
+
+	if o[2].Size != 24 {
+		t.Fatalf("expecting o[2] has size 24: %+v", o[2].Size)
+	}
+
+	o = o.deleteOverflowEntry(4)
+
+	if len(o) != 4 {
+		t.Fatalf("expecting 4 entries now: %+v", o)
+	}
+
+	x, _ := o.findOverflowEntry(5)
+	if x.Key != 5 {
+		t.Fatalf("expecting entry 5 now: %+v", x)
+	}
+
+	for i, x := range o {
+		println("overflow[", i, "]:", x.Key)
+	}
+	println()
+
+	o = o.deleteOverflowEntry(1)
+
+	for i, x := range o {
+		println("overflow[", i, "]:", x.Key)
+	}
+	println()
+
+	o = o.setOverflowEntry(NeedleValue{Key: 4, Offset: 44, Size: 44})
+	for i, x := range o {
+		println("overflow[", i, "]:", x.Key)
+	}
+	println()
+
+	o = o.setOverflowEntry(NeedleValue{Key: 1, Offset: 11, Size: 11})
+
+	for i, x := range o {
+		println("overflow[", i, "]:", x.Key)
+	}
+	println()
+
+}