Пример #1
0
// NewIndexFile returns a new handle to the named index file.
func NewIndexFile(filename string) (*IndexFile, error) {
	v(1, "opening index %q", filename)
	f, err := os.Open(filename)
	if err != nil {
		return nil, fmt.Errorf("error opening file %q: %v", filename, err)
	}
	ss := table.NewReader(f, nil)
	if versions, err := ss.Get([]byte{0}, nil); err != nil {
		return nil, fmt.Errorf("invalid index file %q missing versions record: %v", filename, err)
	} else if len(versions) != 8 {
		return nil, fmt.Errorf("invalid index file %q invalid versions record: %v", filename, versions)
	} else if major, minor := binary.BigEndian.Uint32(versions[:4]), binary.BigEndian.Uint32(versions[4:]); major != majorVersionNumber {
		return nil, fmt.Errorf("invalid index file %q: version mismatch, want %d got %d", filename, majorVersionNumber, major)
	} else {
		v(3, "index file %q has file format version %d:%d", filename, major, minor)
	}
	if *base.VerboseLogging >= 10 {
		iter := ss.Find([]byte{}, nil)
		v(4, "=== %q ===", filename)
		for iter.Next() {
			v(4, "  %v", iter.Key())
		}
		v(4, "  ERR: %v", iter.Close())
	}
	index := &IndexFile{ss: ss, name: filename}
	return index, nil
}
Пример #2
0
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)}
}
Пример #3
0
func main() {
	dbname := "db.dbfs"
	dbfs := db.DefaultFileSystem

	if true {
		f0, _ := dbfs.Create(dbname)
		w := table.NewWriter(f0, nil)

		w.Set([]byte("google"), []byte("oh yes"), nil)

		w.Close() //must call to write to file

	}

	f1, _ := dbfs.Open(dbname)
	r := table.NewReader(f1, nil)
	p(r.Get([]byte("google"), nil))

}
Пример #4
0
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()
}
Пример #5
0
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)
	}
}