| // Copyright 2020 Google LLC |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| |
| // Package publish contains utilities related to publishing messages. |
| package publish |
| |
| import ( |
| "fmt" |
| "strconv" |
| "strings" |
| ) |
| |
| // Metadata holds the result of publishing a message to the Pub/Sub Lite |
| // service. |
| type Metadata struct { |
| // The topic partition the message was published to. |
| Partition int |
| |
| // The offset the message was assigned. |
| Offset int64 |
| } |
| |
| func (m *Metadata) String() string { |
| return fmt.Sprintf("%d:%d", m.Partition, m.Offset) |
| } |
| |
| // ParseMetadata creates Metadata from the ID string of a pubsub.PublishResult |
| // returned by pscompat.PublisherClient or pubsub.Message.ID received from |
| // pscompat.SubscriberClient. |
| func ParseMetadata(id string) (*Metadata, error) { |
| parts := strings.Split(id, ":") |
| if len(parts) != 2 { |
| return nil, fmt.Errorf("pubsublite: invalid encoded publish metadata %q", id) |
| } |
| |
| partition, pErr := strconv.ParseInt(parts[0], 10, 64) |
| offset, oErr := strconv.ParseInt(parts[1], 10, 64) |
| if pErr != nil || oErr != nil { |
| return nil, fmt.Errorf("pubsublite: invalid encoded publish metadata %q", id) |
| } |
| return &Metadata{Partition: int(partition), Offset: offset}, nil |
| } |