Golang KeyValue.Get方法代碼示例

func TestSorted(t *testing.T, kv sorted.KeyValue) {
	defer test.TLog(t)()
	if !isEmpty(t, kv) {
		t.Fatal("kv for test is expected to be initially empty")
	}
	set := func(k, v string) {
		if err := kv.Set(k, v); err != nil {
			t.Fatalf("Error setting %q to %q: %v", k, v, err)
		}
	}
	set("foo", "bar")
	if isEmpty(t, kv) {
		t.Fatalf("iterator reports the kv is empty after adding foo=bar; iterator must be broken")
	}
	if v, err := kv.Get("foo"); err != nil || v != "bar" {
		t.Errorf("get(foo) = %q, %v; want bar", v, err)
	}
	if v, err := kv.Get("NOT_EXIST"); err != sorted.ErrNotFound {
		t.Errorf("get(NOT_EXIST) = %q, %v; want error sorted.ErrNotFound", v, err)
	}
	for i := 0; i < 2; i++ {
		if err := kv.Delete("foo"); err != nil {
			t.Errorf("Delete(foo) (on loop %d/2) returned error %v", i+1, err)
		}
	}
	set("a", "av")
	set("b", "bv")
	set("c", "cv")
	testEnumerate(t, kv, "", "", "av", "bv", "cv")
	testEnumerate(t, kv, "a", "", "av", "bv", "cv")
	testEnumerate(t, kv, "b", "", "bv", "cv")
	testEnumerate(t, kv, "a", "c", "av", "bv")
	testEnumerate(t, kv, "a", "b", "av")
	testEnumerate(t, kv, "a", "a")
	testEnumerate(t, kv, "d", "")
	testEnumerate(t, kv, "d", "e")

	// Verify that < comparison works identically for all DBs (because it is affected by collation rules)
	// http://postgresql.1045698.n5.nabble.com/String-comparison-and-the-SQL-standard-td5740721.html
	set("foo|abc", "foo|abcv")
	testEnumerate(t, kv, "foo|", "", "foo|abcv")
	testEnumerate(t, kv, "foo|", "foo}", "foo|abcv")

	// Verify that the value isn't being used instead of the key in the range comparison.
	set("y", "x:foo")
	testEnumerate(t, kv, "x:", "x~")

	testInsertLarge(t, kv)
	testInsertTooLarge(t, kv)

	// TODO: test batch commits

	// Deleting a non-existent item in a batch should not be an error
	testDeleteNotFoundBatch(t, kv)
	testDeletePartialNotFoundBatch(t, kv)
}

func testDeletePartialNotFoundBatch(t *testing.T, kv sorted.KeyValue) {
	if err := kv.Set(butIExistKey, "whatever"); err != nil {
		t.Fatal(err)
	}
	b := kv.BeginBatch()
	b.Delete(notExistKey)
	b.Delete(butIExistKey)
	if err := kv.CommitBatch(b); err != nil {
		t.Fatalf("Batch deletion with one non existing key returned an error: %v", err)
	}
	if val, err := kv.Get(butIExistKey); err != sorted.ErrNotFound || val != "" {
		t.Fatalf("Key %q should have been batch deleted", butIExistKey)
	}
}

func (s *storage) reindexOne(ctx *context.Context, index sorted.KeyValue, overwrite bool, packID int) error {

	var batch sorted.BatchMutation
	if overwrite {
		batch = index.BeginBatch()
	}
	allOk := true

	// TODO(tgulacsi): proper verbose from context
	verbose := camliDebug
	err := s.walkPack(verbose, packID,
		func(packID int, ref blob.Ref, offset int64, size uint32) error {
			if !ref.Valid() {
				if camliDebug {
					log.Printf("found deleted blob in %d at %d with size %d", packID, offset, size)
				}
				return nil
			}
			meta := blobMeta{packID, offset, size}.String()
			if overwrite && batch != nil {
				batch.Set(ref.String(), meta)
			} else {
				if old, err := index.Get(ref.String()); err != nil {
					allOk = false
					if err == sorted.ErrNotFound {
						log.Println(ref.String() + ": cannot find in index!")
					} else {
						log.Println(ref.String()+": error getting from index: ", err.Error())
					}
				} else if old != meta {
					allOk = false
					log.Printf("%s: index mismatch - index=%s data=%s", ref.String(), old, meta)
				}
			}
			return nil
		})
	if err != nil {
		return err
	}

	if overwrite && batch != nil {
		log.Printf("overwriting %s from %d", index, packID)
		if err = index.CommitBatch(batch); err != nil {
			return err
		}
	} else if !allOk {
		return fmt.Errorf("index does not match data in %d", packID)
	}
	return nil
}

func testInsertLarge(t *testing.T, kv sorted.KeyValue) {
	largeKey := make([]byte, sorted.MaxKeySize-1)
	// setting all the bytes because postgres whines about an invalid byte sequence
	// otherwise
	for k, _ := range largeKey {
		largeKey[k] = 'A'
	}
	largeKey[sorted.MaxKeySize-2] = 'B'
	largeValue := make([]byte, sorted.MaxValueSize-1)
	for k, _ := range largeValue {
		largeValue[k] = 'A'
	}
	largeValue[sorted.MaxValueSize-2] = 'B'

	// insert with large key
	if err := kv.Set(string(largeKey), "whatever"); err != nil {
		t.Fatalf("Insertion of large key failed: %v", err)
	}

	// and verify we can get it back, i.e. that the key hasn't been truncated.
	it := kv.Find(string(largeKey), "")
	if !it.Next() || it.Key() != string(largeKey) || it.Value() != "whatever" {
		it.Close()
		t.Fatalf("Find(largeKey) = %q, %q; want %q, %q", it.Key(), it.Value(), largeKey, "whatever")
	}
	it.Close()

	// insert with large value
	if err := kv.Set("whatever", string(largeValue)); err != nil {
		t.Fatalf("Insertion of large value failed: %v", err)
	}
	// and verify we can get it back, i.e. that the value hasn't been truncated.
	if v, err := kv.Get("whatever"); err != nil || v != string(largeValue) {
		t.Fatalf("get(\"whatever\") = %q, %v; want %q", v, err, largeValue)
	}

	// insert with large key and large value
	if err := kv.Set(string(largeKey), string(largeValue)); err != nil {
		t.Fatalf("Insertion of large key and value failed: %v", err)
	}
	// and verify we can get them back
	it = kv.Find(string(largeKey), "")
	defer it.Close()
	if !it.Next() || it.Key() != string(largeKey) || it.Value() != string(largeValue) {
		t.Fatalf("Find(largeKey) = %q, %q; want %q, %q", it.Key(), it.Value(), largeKey, largeValue)
	}
}

func TestSorted(t *testing.T, kv sorted.KeyValue) {
	defer test.TLog(t)()
	if !isEmpty(t, kv) {
		t.Fatal("kv for test is expected to be initially empty")
	}
	set := func(k, v string) {
		if err := kv.Set(k, v); err != nil {
			t.Fatalf("Error setting %q to %q: %v", k, v, err)
		}
	}
	set("foo", "bar")
	if isEmpty(t, kv) {
		t.Fatalf("iterator reports the kv is empty after adding foo=bar; iterator must be broken")
	}
	if v, err := kv.Get("foo"); err != nil || v != "bar" {
		t.Errorf("get(foo) = %q, %v; want bar", v, err)
	}
	if v, err := kv.Get("NOT_EXIST"); err != sorted.ErrNotFound {
		t.Errorf("get(NOT_EXIST) = %q, %v; want error sorted.ErrNotFound", v, err)
	}
	for i := 0; i < 2; i++ {
		if err := kv.Delete("foo"); err != nil {
			t.Errorf("Delete(foo) (on loop %d/2) returned error %v", i+1, err)
		}
	}
	set("a", "av")
	set("b", "bv")
	set("c", "cv")
	testEnumerate(t, kv, "", "", "av", "bv", "cv")
	testEnumerate(t, kv, "a", "", "av", "bv", "cv")
	testEnumerate(t, kv, "b", "", "bv", "cv")
	testEnumerate(t, kv, "a", "c", "av", "bv")
	testEnumerate(t, kv, "a", "b", "av")
	testEnumerate(t, kv, "a", "a")
	testEnumerate(t, kv, "d", "")
	testEnumerate(t, kv, "d", "e")

	// Verify that the value isn't being used instead of the key in the range comparison.
	set("y", "x:foo")
	testEnumerate(t, kv, "x:", "x~")

	// TODO: test batch commits
}

func testInsertTooLarge(t *testing.T, kv sorted.KeyValue) {
	largeKey := make([]byte, sorted.MaxKeySize+1)
	largeValue := make([]byte, sorted.MaxValueSize+1)
	err := kv.Set(string(largeKey), "whatever")
	if err != nil {
		t.Fatalf("Insertion of too large a key should have skipped with some logging, but err was %v", err)
	}
	_, err = kv.Get(string(largeKey))
	if err == nil {
		t.Fatal("large key should not have been inserted")
	}
	err = kv.Set("testInsertTooLarge", string(largeValue))
	if err != nil {
		t.Fatalf("Insertion of too large a value should have skipped with some logging, but err was %v", err)
	}
	_, err = kv.Get("testInsertTooLarge")
	if err == nil {
		t.Fatal("large value should not have been inserted")
	}
}

func (s *storage) reindexOne(ctx *context.Context, index sorted.KeyValue, overwrite bool, packID int) error {

	var batch sorted.BatchMutation
	if overwrite {
		batch = index.BeginBatch()
	}
	allOk := true

	// TODO(tgulacsi): proper verbose from context
	verbose := env.IsDebug()
	misses := make(map[blob.Ref]string, 8)
	err := s.walkPack(verbose, packID,
		func(packID int, ref blob.Ref, offset int64, size uint32) error {
			if !ref.Valid() {
				if verbose {
					log.Printf("found deleted blob in %d at %d with size %d", packID, offset, size)
				}
				return nil
			}
			meta := blobMeta{packID, offset, size}.String()
			if overwrite && batch != nil {
				batch.Set(ref.String(), meta)
				return nil
			}
			if _, ok := misses[ref]; ok { // maybe this is the last of this blob.
				delete(misses, ref)
			}
			if old, err := index.Get(ref.String()); err != nil {
				allOk = false
				if err == sorted.ErrNotFound {
					log.Println(ref.String() + ": cannot find in index!")
				} else {
					log.Println(ref.String()+": error getting from index: ", err.Error())
				}
			} else if old != meta {
				if old > meta {
					misses[ref] = meta
					log.Printf("WARN: possible duplicate blob %s", ref.String())
				} else {
					allOk = false
					log.Printf("ERROR: index mismatch for %s - index=%s, meta=%s!", ref.String(), old, meta)
				}
			}
			return nil
		})
	if err != nil {
		return err
	}

	for ref, meta := range misses {
		log.Printf("ERROR: index mismatch for %s (%s)!", ref.String(), meta)
		allOk = false
	}

	if overwrite && batch != nil {
		if err := index.CommitBatch(batch); err != nil {
			return err
		}
	} else if !allOk {
		return fmt.Errorf("index does not match data in %d", packID)
	}
	return nil
}

func reindexOne(index sorted.KeyValue, overwrite, verbose bool, r io.ReadSeeker, name string, packId int64) error {
	l, err := lock.Lock(name + ".lock")
	defer l.Close()

	var pos, size int64

	errAt := func(prefix, suffix string) error {
		if prefix != "" {
			prefix = prefix + " "
		}
		if suffix != "" {
			suffix = " " + suffix
		}
		return fmt.Errorf(prefix+"at %d (0x%x) in %q:"+suffix, pos, pos, name)
	}

	var batch sorted.BatchMutation
	if overwrite {
		batch = index.BeginBatch()
	}

	allOk := true
	br := bufio.NewReaderSize(r, 512)
	for {
		if b, err := br.ReadByte(); err != nil {
			if err == io.EOF {
				break
			}
			return errAt("error while reading", err.Error())
		} else if b != '[' {
			return errAt(fmt.Sprintf("found byte 0x%x", b), "but '[' should be here!")
		}
		chunk, err := br.ReadSlice(']')
		if err != nil {
			if err == io.EOF {
				break
			}
			return errAt("error reading blob header", err.Error())
		}
		m := len(chunk)
		chunk = chunk[:m-1]
		i := bytes.IndexByte(chunk, byte(' '))
		if i <= 0 {
			return errAt("", fmt.Sprintf("bad header format (no space in %q)", chunk))
		}
		if size, err = strconv.ParseInt(string(chunk[i+1:]), 10, 64); err != nil {
			return errAt(fmt.Sprintf("cannot parse size %q as int", chunk[i+1:]), err.Error())
		}
		ref, ok := blob.Parse(string(chunk[:i]))
		if !ok {
			return errAt("", fmt.Sprintf("cannot parse %q as blobref", chunk[:i]))
		}
		if verbose {
			log.Printf("found %s at %d", ref, pos)
		}

		meta := blobMeta{packId, pos + 1 + int64(m), size}.String()
		if overwrite && batch != nil {
			batch.Set(ref.String(), meta)
		} else {
			if old, err := index.Get(ref.String()); err != nil {
				allOk = false
				if err == sorted.ErrNotFound {
					log.Println(ref.String() + ": cannot find in index!")
				} else {
					log.Println(ref.String()+": error getting from index: ", err.Error())
				}
			} else if old != meta {
				allOk = false
				log.Printf("%s: index mismatch - index=%s data=%s", ref.String(), old, meta)
			}
		}

		pos += 1 + int64(m)
		// TODO(tgulacsi78): not just seek, but check the hashes of the files
		// maybe with a different command-line flag, only.
		if pos, err = r.Seek(pos+size, 0); err != nil {
			return errAt("", "cannot seek +"+strconv.FormatInt(size, 10)+" bytes")
		}
		// drain the buffer after the underlying reader Seeks
		io.CopyN(ioutil.Discard, br, int64(br.Buffered()))
	}

	if overwrite && batch != nil {
		log.Printf("overwriting %s from %s", index, name)
		if err = index.CommitBatch(batch); err != nil {
			return err
		}
	} else if !allOk {
		return fmt.Errorf("index does not match data in %q", name)
	}
	return nil
}