diff options
Diffstat (limited to 'swarm/storage/feeds/timestampprovider.go')
-rw-r--r-- | swarm/storage/feeds/timestampprovider.go | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/swarm/storage/feeds/timestampprovider.go b/swarm/storage/feeds/timestampprovider.go new file mode 100644 index 000000000..f6aa0775c --- /dev/null +++ b/swarm/storage/feeds/timestampprovider.go @@ -0,0 +1,84 @@ +// Copyright 2018 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. + +package feeds + +import ( + "encoding/binary" + "encoding/json" + "time" +) + +// TimestampProvider sets the time source of the feeds package +var TimestampProvider timestampProvider = NewDefaultTimestampProvider() + +// Timestamp encodes a point in time as a Unix epoch +type Timestamp struct { + Time uint64 `json:"time"` // Unix epoch timestamp, in seconds +} + +// 8 bytes uint64 Time +const timestampLength = 8 + +// timestampProvider interface describes a source of timestamp information +type timestampProvider interface { + Now() Timestamp // returns the current timestamp information +} + +// binaryGet populates the timestamp structure from the given byte slice +func (t *Timestamp) binaryGet(data []byte) error { + if len(data) != timestampLength { + return NewError(ErrCorruptData, "timestamp data has the wrong size") + } + t.Time = binary.LittleEndian.Uint64(data[:8]) + return nil +} + +// binaryPut Serializes a Timestamp to a byte slice +func (t *Timestamp) binaryPut(data []byte) error { + if len(data) != timestampLength { + return NewError(ErrCorruptData, "timestamp data has the wrong size") + } + binary.LittleEndian.PutUint64(data, t.Time) + return nil +} + +// UnmarshalJSON implements the json.Unmarshaller interface +func (t *Timestamp) UnmarshalJSON(data []byte) error { + return json.Unmarshal(data, &t.Time) +} + +// MarshalJSON implements the json.Marshaller interface +func (t *Timestamp) MarshalJSON() ([]byte, error) { + return json.Marshal(t.Time) +} + +// DefaultTimestampProvider is a TimestampProvider that uses system time +// as time source +type DefaultTimestampProvider struct { +} + +// NewDefaultTimestampProvider creates a system clock based timestamp provider +func NewDefaultTimestampProvider() *DefaultTimestampProvider { + return &DefaultTimestampProvider{} +} + +// Now returns the current time according to this provider +func (dtp *DefaultTimestampProvider) Now() Timestamp { + return Timestamp{ + Time: uint64(time.Now().Unix()), + } +} |