As we work towards introducing consumer groups to the repository we need a more generic name for the persistence layer for storing checkpoints and leases for given shards.
* Rename `checkpoint` to `store`
* Introduce Group interface and AllGroup
As we move towards consumer groups we'll need to support the current
"consume all shards" strategy, and setup the codebase for the
anticipated "consume balanced shards."
Having consumers start at latest record seems like a reasonable default.
This can also be overridden with optional config, make sure that is
documented for users of the library.
Fixes: https://github.com/harlow/kinesis-consumer/issues/86
* Use shard broker to start processing new shards
The addition of a shard broker will allow the consumer to be notified
when new shards are added to the stream so it can consume them.
Fixes: https://github.com/harlow/kinesis-consumer/issues/36
Major changes:
```go
type ScanFunc func(r *Record) error
```
* Simplify the callback func signature by removing `ScanStatus`
* Leverage context for cancellation
* Add custom error `SkipCheckpoint` for special cases when we don't want to checkpoint
Minor changes:
* Use kinesis package constants for shard iterator types
* Move optional config to new file
See conversation on #75 for more details
Changes:
* I add postgres_databaseutils_test.go for containing all utilities for mocking the database.
* I put appName as a required parameter passed to the New() since it is needed to form the namespace column name.
* I add GetMaxInterval() since it might be needed by the consumer and the test.
* I move the SQL string package variables directly into the function that need it so we could avoid maintenance nightmare in the future.
Having an additional Client has added some confusion (https://github.com/harlow/kinesis-consumer/issues/45) on how to provide a
custom kinesis client. Allowing `WithClient` to accept a Kinesis client
it cleans up the interface.
Major changes:
* Remove the Client wrapper; prefer using kinesis client directly
* Change `ScanError` to `ScanStatus` as the return value isn't necessarily an error
Note: these are breaking changes, if you need last stable release please see here: https://github.com/harlow/kinesis-consumer/releases/tag/v0.2.0
