func (n *tableCacheNode) load(c *tableCache) {
// Try opening the fileTypeTable first. If that file doesn't exist,
// fall back onto the fileTypeOldFashionedTable.
f, err := c.fs.Open(dbFilename(c.dirname, fileTypeTable, n.fileNum))
if os.IsNotExist(err) {
f, err = c.fs.Open(dbFilename(c.dirname, fileTypeOldFashionedTable, n.fileNum))
}
if err != nil {
n.result <- tableReaderOrError{err: err}
return
}
n.result <- tableReaderOrError{reader: table.NewReader(f, c.opts)}
}
func dump(filename string) error {
f, err := os.Open(filename)
if err != nil {
return err
}
// No need to "defer f.Close()", as closing r will close f.
r := table.NewReader(f, &db.Options{
VerifyChecksums: *verifyChecksums,
})
defer r.Close()
t := r.Find(nil, nil)
for t.Next() {
k, v := t.Key(), t.Value()
if *truncate {
k = trunc(&kBuf, k)
v = trunc(&vBuf, v)
}
fmt.Printf("%q: %q,\n", k, v)
}
return t.Close()
}
func TestCompaction(t *testing.T) {
const writeBufferSize = 1000
fs := memfs.New()
d, err := Open("", &db.Options{
FileSystem: fs,
WriteBufferSize: writeBufferSize,
})
if err != nil {
t.Fatalf("Open: %v", err)
}
get1 := func(x db.DB) (ret string) {
b := &bytes.Buffer{}
iter := x.Find(nil, nil)
for iter.Next() {
b.Write(internalKey(iter.Key()).ukey())
}
if err := iter.Close(); err != nil {
t.Fatalf("iterator Close: %v", err)
}
return b.String()
}
getAll := func() (gotMem, gotDisk string, err error) {
d.mu.Lock()
defer d.mu.Unlock()
if d.mem != nil {
gotMem = get1(d.mem)
}
ss := []string(nil)
v := d.versions.currentVersion()
for _, files := range v.files {
for _, meta := range files {
f, err := fs.Open(dbFilename("", fileTypeTable, meta.fileNum))
if err != nil {
return "", "", fmt.Errorf("Open: %v", err)
}
defer f.Close()
r := table.NewReader(f, &db.Options{
Comparer: internalKeyComparer{db.DefaultComparer},
})
defer r.Close()
ss = append(ss, get1(r)+".")
}
}
sort.Strings(ss)
return gotMem, strings.Join(ss, ""), nil
}
value := bytes.Repeat([]byte("x"), writeBufferSize*6/10)
testCases := []struct {
key, wantMem, wantDisk string
}{
{"+A", "A", ""},
{"+a", "Aa", ""},
{"+B", "B", "Aa."},
{"+b", "Bb", "Aa."},
// The next level-0 table overwrites the B key.
{"+C", "C", "Aa.Bb."},
{"+B", "BC", "Aa.Bb."},
// The next level-0 table deletes the a key.
{"+D", "D", "Aa.BC.Bb."},
{"-a", "Da", "Aa.BC.Bb."},
{"+d", "Dad", "Aa.BC.Bb."},
// The next addition creates the fourth level-0 table, and l0CompactionTrigger == 4,
// so this triggers a non-trivial compaction into one level-1 table. Note that the
// keys in this one larger table are interleaved from the four smaller ones.
{"+E", "E", "ABCDbd."},
{"+e", "Ee", "ABCDbd."},
{"+F", "F", "ABCDbd.Ee."},
}
for _, tc := range testCases {
if key := tc.key[1:]; tc.key[0] == '+' {
if err := d.Set([]byte(key), value, nil); err != nil {
t.Errorf("%q: Set: %v", key, err)
break
}
} else {
if err := d.Delete([]byte(key), nil); err != nil {
t.Errorf("%q: Delete: %v", key, err)
break
}
}
// Allow any writes to the memfs to complete.
time.Sleep(1 * time.Millisecond)
gotMem, gotDisk, err := getAll()
if err != nil {
t.Errorf("%q: %v", tc.key, err)
break
}
if gotMem != tc.wantMem {
t.Errorf("%q: mem: got %q, want %q", tc.key, gotMem, tc.wantMem)
}
if gotDisk != tc.wantDisk {
t.Errorf("%q: ldb: got %q, want %q", tc.key, gotDisk, tc.wantDisk)
}
}
if err := d.Close(); err != nil {
t.Fatalf("db Close: %v", err)
}
}