Golang datastore.Keyspace类代码示例

// Helper function to perform a primary index scan on the given keyspace. Returns a map of
// all primary key names.
func doPrimaryIndexScan(t *testing.T, b datastore.Keyspace) (m map[string]bool, excp errors.Error) {
	conn := datastore.NewIndexConnection(&testingContext{t})

	m = map[string]bool{}

	nitems, excp := b.Count()
	if excp != nil {
		t.Fatalf("failed to get keyspace count")
		return
	}

	indexers, excp := b.Indexers()
	if excp != nil {
		t.Fatalf("failed to retrieve indexers")
		return
	}

	pindexes, excp := indexers[0].PrimaryIndexes()
	if excp != nil || len(pindexes) < 1 {
		t.Fatalf("failed to retrieve primary indexes")
		return
	}

	idx := pindexes[0]
	go idx.ScanEntries("", nitems, datastore.UNBOUNDED, nil, conn)
	for {
		v, ok := <-conn.EntryChannel()
		if !ok {
			// Channel closed => Scan complete
			return
		}

		m[v.PrimaryKey] = true
	}
}

func allIndexes(keyspace datastore.Keyspace) ([]datastore.Index, error) {
	indexers, err := keyspace.Indexers()
	if err != nil {
		return nil, err
	}

	indexes := make([]datastore.Index, 0, len(indexers)*16)

	for _, indexer := range indexers {
		idxes, err := indexer.Indexes()
		if err != nil {
			return nil, err
		}

		for _, idx := range idxes {
			state, _, er := idx.State()
			if er != nil {
				logging.Errorp("Index selection", logging.Pair{"error", er.Error()})
			}

			if er != nil || state != datastore.ONLINE {
				continue
			}

			indexes = append(indexes, idx)
		}
	}

	return indexes, nil
}

func allHints(keyspace datastore.Keyspace, hints algebra.IndexRefs) ([]datastore.Index, error) {
	indexes := make([]datastore.Index, 0, len(hints))

	for _, hint := range hints {
		indexer, err := keyspace.Indexer(hint.Using())
		if err != nil {
			return nil, err
		}

		index, err := indexer.IndexByName(hint.Name())
		if err != nil {
			return nil, err
		}

		state, _, er := index.State()
		if er != nil {
			logging.Errorp("Index selection", logging.Pair{"error", er.Error()})
		}

		if er != nil || state != datastore.ONLINE {
			continue
		}

		indexes = append(indexes, index)
	}

	return indexes, nil
}

// Helper function to scan the primary index of given keyspace with given span
func doIndexScan(t *testing.T, b datastore.Keyspace, span *datastore.Span) (
	e []*datastore.IndexEntry, excp errors.Error) {
	conn := datastore.NewIndexConnection(&testingContext{t})
	e = []*datastore.IndexEntry{}

	nitems, excp := b.Count()
	if excp != nil {
		t.Fatalf("failed to get keyspace count")
		return
	}

	indexers, excp := b.Indexers()
	if excp != nil {
		t.Fatalf("failed to retrieve indexers")
		return
	}

	idx, excp := indexers[0].IndexByName("#primary")
	if excp != nil {
		t.Fatalf("failed to retrieve primary index")
		return
	}

	go idx.Scan("", span, false, nitems, datastore.UNBOUNDED, nil, conn)

	for {
		entry, ok := <-conn.EntryChannel()
		if !ok {
			return
		}

		e = append(e, entry)
	}

	return
}

func buildPrimaryIndex(keyspace datastore.Keyspace, hintIndexes, otherIndexes []datastore.Index) (
	primary datastore.PrimaryIndex, err error) {
	ok := false

	// Prefer hints
	for _, index := range hintIndexes {
		if !index.IsPrimary() {
			continue
		}

		primary, ok = index.(datastore.PrimaryIndex)
		if ok {
			return
		} else {
			return nil, fmt.Errorf("Unable to cast primary index %s", index.Name())
		}
	}

	// Consider other primary indexes
	if otherIndexes != nil {
		for _, index := range otherIndexes {
			if !index.IsPrimary() {
				continue
			}

			primary, ok = index.(datastore.PrimaryIndex)
			if ok {
				return
			} else {
				return nil, fmt.Errorf("Unable to cast primary index %s", index.Name())
			}
		}
	}

	// Return first online primary index
	indexers, er := keyspace.Indexers()
	if er != nil {
		return nil, err
	}

	for _, indexer := range indexers {
		primaries, er := indexer.PrimaryIndexes()
		if er != nil {
			return nil, er
		}

		for _, primary = range primaries {
			state, _, er := primary.State()
			if er != nil {
				return nil, er
			}

			if state == datastore.ONLINE {
				return
			}
		}
	}

	if primary == nil {
		return nil, fmt.Errorf(
			"No primary index on keyspace %s. Use CREATE PRIMARY INDEX to create one.",
			keyspace.Name())
	}

	return nil, fmt.Errorf("Primary index %s not online.", primary.Name())
}