Golang NewFieldCodec Examples

Example #1

File: reader.go Project: shiwen5/influxdb

// Open opens the reader.
func (r *Reader) Open() error {
	// Open underlying storage.
	db, err := bolt.Open(r.path, 0666, &bolt.Options{Timeout: 1 * time.Second})
	if err != nil {
		return err
	}
	r.db = db

	if err := r.db.View(func(tx *bolt.Tx) error {
		var data []byte

		meta := tx.Bucket([]byte("meta"))
		if meta == nil {
			// No data in this shard.
			return nil
		}
		buf := meta.Get([]byte("series"))
		if buf == nil {
			// No data in this shard.
			return nil
		}
		data, err = snappy.Decode(nil, buf)
		if err != nil {
			return err
		}
		if err := json.Unmarshal(data, &r.series); err != nil {
			return err
		}

		buf = meta.Get([]byte("fields"))
		if buf == nil {
			// No data in this shard.
			return nil
		}

		data, err = snappy.Decode(nil, buf)
		if err != nil {
			return err
		}
		if err := json.Unmarshal(data, &r.fields); err != nil {
			return err
		}
		return nil
	}); err != nil {
		return err
	}

	// Build the codec for each measurement.
	for k, v := range r.fields {
		r.codecs[k] = tsdb.NewFieldCodec(v.Fields)
	}

	// Create cursor for each field of each series.
	r.tx, err = r.db.Begin(false)
	if err != nil {
		return err
	}
	for s, _ := range r.series {
		if err != nil {
			return err
		}

		measurement := tsdb.MeasurementFromSeriesKey(s)
		for _, f := range r.fields[tsdb.MeasurementFromSeriesKey(s)].Fields {
			c := newCursor(r.tx, s, f.Name, r.codecs[measurement])
			c.SeekTo(0)
			r.cursors = append(r.cursors, c)
		}
	}
	sort.Sort(cursors(r.cursors))

	return nil
}

Example #2

File: reader.go Project: rhyolight/influxdb

// Open opens the reader.
func (r *Reader) Open() error {
	// Open underlying storage.
	db, err := bolt.Open(r.path, 0666, &bolt.Options{Timeout: 1 * time.Second})
	if err != nil {
		return err
	}
	r.db = db

	// Load fields.
	if err := r.db.View(func(tx *bolt.Tx) error {
		meta := tx.Bucket([]byte("fields"))
		c := meta.Cursor()

		for k, v := c.First(); k != nil; k, v = c.Next() {
			mf := &tsdb.MeasurementFields{}
			if err := mf.UnmarshalBinary(v); err != nil {
				return err
			}
			r.fields[string(k)] = mf
			r.codecs[string(k)] = tsdb.NewFieldCodec(mf.Fields)
		}
		return nil
	}); err != nil {
		return err
	}

	// Load series
	if err := r.db.View(func(tx *bolt.Tx) error {
		meta := tx.Bucket([]byte("series"))
		c := meta.Cursor()

		for k, v := c.First(); k != nil; k, v = c.Next() {
			series := &tsdb.Series{}
			if err := series.UnmarshalBinary(v); err != nil {
				return err
			}
			r.series[string(k)] = series
		}
		return nil
	}); err != nil {
		return err
	}

	// Create cursor for each field of each series.
	r.tx, err = r.db.Begin(false)
	if err != nil {
		return err
	}
	for s, _ := range r.series {
		if err != nil {
			return err
		}

		measurement := tsdb.MeasurementFromSeriesKey(s)
		fields := r.fields[tsdb.MeasurementFromSeriesKey(s)]
		if fields == nil {
			atomic.AddUint64(&NoFieldsFiltered, 1)
			continue
		}
		for _, f := range fields.Fields {
			c := newCursor(r.tx, s, f.Name, r.codecs[measurement])
			c.SeekTo(0)
			r.cursors = append(r.cursors, c)
		}
	}
	sort.Sort(cursors(r.cursors))

	return nil
}