func TestDb_BloomFilter(t *testing.T) {
h := newDbHarnessWopt(t, &opt.Options{
BlockCache: opt.NoCache,
Filter: filter.NewBloomFilter(10),
})
defer h.close()
key := func(i int) string {
return fmt.Sprintf("key%06d", i)
}
const (
n = 10000
indexOverheat = 19898
filterOverheat = 19799
)
// Populate multiple layers
for i := 0; i < n; i++ {
h.put(key(i), key(i))
}
h.compactMem()
h.compactRange("a", "z")
for i := 0; i < n; i += 100 {
h.put(key(i), key(i))
}
h.compactMem()
// Prevent auto compactions triggered by seeks
h.stor.DelaySync(storage.TypeTable)
// Lookup present keys. Should rarely read from small sstable.
h.stor.SetReadCounter(storage.TypeTable)
for i := 0; i < n; i++ {
h.getVal(key(i), key(i))
}
cnt := int(h.stor.ReadCounter())
t.Logf("lookup of %d present keys yield %d sstable I/O reads", n, cnt)
if min, max := n+indexOverheat+filterOverheat, n+indexOverheat+filterOverheat+2*n/100; cnt < min || cnt > max {
t.Errorf("num of sstable I/O reads of present keys not in range of %d - %d, got %d", min, max, cnt)
}
// Lookup missing keys. Should rarely read from either sstable.
h.stor.ResetReadCounter()
for i := 0; i < n; i++ {
h.get(key(i)+".missing", false)
}
cnt = int(h.stor.ReadCounter())
t.Logf("lookup of %d missing keys yield %d sstable I/O reads", n, cnt)
if max := 3*n/100 + indexOverheat + filterOverheat; cnt > max {
t.Errorf("num of sstable I/O reads of missing keys was more than %d, got %d", max, cnt)
}
h.stor.ReleaseSync(storage.TypeTable)
}
Key() []byte
Value() []byte
}
func testKeyVal(t *testing.T, kv keyValue, want string) {
res := string(kv.Key()) + "->" + string(kv.Value())
if res != want {
t.Errorf("invalid key/value, want=%q, got=%q", want, res)
}
}
func numKey(num int) string {
return fmt.Sprintf("key%06d", num)
}
var _bloom_filter = filter.NewBloomFilter(10)
func truno(t *testing.T, o *opt.Options, f func(h *dbHarness)) {
for i := 0; i < 4; i++ {
func() {
switch i {
case 0:
case 1:
if o == nil {
o = &opt.Options{Filter: _bloom_filter}
} else {
old := o
o = &opt.Options{}
*o = *old
o.Filter = _bloom_filter
}