kinesis-consumer/checkpoints.go
Harlow Ward 57dc74bd48 Add checkpoint interface
* Add first checkpoint implementation of RedisCheckpoint.
* Move MsgBuffer into the buffers.go file.
2014-07-27 21:13:34 -07:00

45 lines
1 KiB
Go

package etl
import (
"fmt"
"github.com/hoisie/redis"
)
type Checkpoint interface {
CheckpointExists(streamName string, shardID string) bool
SequenceNumber() string
SetCheckpoint(streamName string, shardId string, sequenceNumber string)
}
type RedisCheckpoint struct {
appName string
client redis.Client
sequenceNumber string
}
func (c RedisCheckpoint) SequenceNumber() string {
return c.sequenceNumber
}
func (c *RedisCheckpoint) CheckpointExists(streamName string, shardId string) bool {
key := c.keyGen(streamName, shardId)
val, _ := c.client.Get(key)
if val != nil {
c.sequenceNumber = string(val)
return true
} else {
return false
}
}
func (c *RedisCheckpoint) SetCheckpoint(streamName string, shardId string, sequenceNumber string) {
key := c.keyGen(streamName, shardId)
c.client.Set(key, []byte(sequenceNumber))
c.sequenceNumber = sequenceNumber
}
func (c RedisCheckpoint) keyGen(streamName string, shardId string) string {
return fmt.Sprintf("%v:checkpoint:%v:%v", c.appName, streamName, shardId)
}