| // Package statemgr defines the interfaces and some supporting functionality |
| // for "state managers", which are components responsible for writing state |
| // to some persistent storage and then later retrieving it. |
| // |
| // State managers will usually (but not necessarily) use the state file formats |
| // implemented in the sibling directory "statefile" to serialize the persistent |
| // parts of state for storage. |
| // |
| // State managers are responsible for ensuring that stored state can be updated |
| // safely across multiple, possibly-concurrent Terraform runs (with reasonable |
| // constraints and limitations). The rest of Terraform considers state to be |
| // a mutable data structure, with state managers preserving that illusion |
| // by creating snapshots of the state and updating them over time. |
| // |
| // From the perspective of callers of the general state manager API, a state |
| // manager is able to return the latest snapshot and to replace that snapshot |
| // with a new one. Some state managers may also preserve historical snapshots |
| // using facilities offered by their storage backend, but this is always an |
| // implementation detail: the historical versions are not visible to a user |
| // of these interfaces. |
| package statemgr |
