RefCache (Gerrit Review Plugin API Documentation)

All Known Implementing Classes:

ChainedReceiveCommands, RepoRefCache
```
public interface RefCache
```
Simple short-lived cache of individual refs read from a repo.
Within a single request that is known to read a small bounded number of refs, this class can be used to ensure a consistent view of one ref, and avoid multiple system calls to read refs multiple times.
Note: Implementations of this class are only appropriate for short-term caching, and do not support invalidation. It is also not threadsafe.

- Method Summary
  
  All Methods Instance Methods Abstract Methods
  Modifier and Type Method Description
  
  Optional<org.eclipse.jgit.lib.ObjectId> get(String refName)
  Get the possibly-cached value of a ref.

- Method Detail
  - get
```
Optional<org.eclipse.jgit.lib.ObjectId> get(String refName)
                                     throws IOException
```
    Get the possibly-cached value of a ref.
    
    Parameters:
    
    refName - name of the ref.
    
    Returns:
    
    value of the ref; absent if the ref does not exist in the repo. Never null, and never present with a value of ObjectId.zeroId().
    
    Throws:
    
    IOException