org.eclipse.jgit.internal.storage.dfs

Class InMemoryRepository.MemRefDatabase

java.lang.Object

org.eclipse.jgit.lib.RefDatabase

org.eclipse.jgit.internal.storage.dfs.DfsRefDatabase

org.eclipse.jgit.internal.storage.dfs.InMemoryRepository.MemRefDatabase

Enclosing class:

InMemoryRepository

protected class InMemoryRepository.MemRefDatabase
extends DfsRefDatabase

A ref database storing all refs in-memory.

This class is protected (and not private) to facilitate testing using subclasses of InMemoryRepository.

Nested Class Summary

Nested classes/interfaces inherited from class org.eclipse.jgit.internal.storage.dfs.DfsRefDatabase

DfsRefDatabase.RefCache

Field Summary

Fields inherited from class org.eclipse.jgit.lib.RefDatabase

ALL, MAX_SYMBOLIC_REF_DEPTH, SEARCH_PATH

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	MemRefDatabase() Initialize a new in-memory ref database.

Method Summary

Modifier and Type	Method and Description
protected boolean	compareAndPut(Ref oldRef, Ref newRef) Compare a reference, and put if it matches.
protected boolean	compareAndRemove(Ref oldRef) Compare a reference, and delete if it matches.
BatchRefUpdate	newBatchUpdate() Create a new batch update to attempt on this database.
boolean	performsAtomicTransactions() Whether the database is capable of performing batch updates as atomic transactions.
protected DfsRefDatabase.RefCache	scanAllRefs() Read all known references in the repository.

Methods inherited from class org.eclipse.jgit.internal.storage.dfs.DfsRefDatabase

cachePeeledState, close, create, exactRef, getAdditionalRefs, getRef, getRefs, getRepository, isNameConflicting, newRename, newUpdate, peel, refresh

Methods inherited from class org.eclipse.jgit.lib.RefDatabase

exactRef, findRef, firstExactRef, getConflictingNames

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MemRefDatabase

protected MemRefDatabase()

Initialize a new in-memory ref database.

Method Detail

performsAtomicTransactions

public boolean performsAtomicTransactions()

Description copied from class: RefDatabase

Whether the database is capable of performing batch updates as atomic transactions.

If true, by default BatchRefUpdate instances will perform updates atomically, meaning either all updates will succeed, or all updates will fail. It is still possible to turn off this behavior on a per-batch basis by calling update.setAtomic(false).

If false, BatchRefUpdate instances will never perform updates atomically, and calling update.setAtomic(true) will cause the entire batch to fail with REJECTED_OTHER_REASON.

This definition of atomicity is stronger than what is provided by ReceivePack. ReceivePack will attempt to reject all commands if it knows in advance some commands may fail, even if the storage layer does not support atomic transactions. Here, atomicity applies even in the case of unforeseeable errors.

Overrides:

performsAtomicTransactions in class RefDatabase

Returns:

whether transactions are atomic by default.

newBatchUpdate

public BatchRefUpdate newBatchUpdate()

Description copied from class: RefDatabase

Create a new batch update to attempt on this database.

The default implementation performs a sequential update of each command.

Overrides:

newBatchUpdate in class RefDatabase

Returns:

a new batch update object.

scanAllRefs

protected DfsRefDatabase.RefCache scanAllRefs()
                                       throws IOException

Description copied from class: DfsRefDatabase

Read all known references in the repository.

Specified by:

scanAllRefs in class DfsRefDatabase

Returns:

all current references of the repository.

Throws:

IOException - references cannot be accessed.

compareAndPut

protected boolean compareAndPut(Ref oldRef,
                                Ref newRef)
                         throws IOException

Description copied from class: DfsRefDatabase

Compare a reference, and put if it matches.

Two reference match if and only if they satisfy the following:

• If one reference is a symbolic ref, the other one should be a symbolic ref.
• If both are symbolic refs, the target names should be same.
• If both are object ID refs, the object IDs should be same.

Specified by:

compareAndPut in class DfsRefDatabase

Parameters:

oldRef - old value to compare to. If the reference is expected to not exist the old value has a storage of Ref.Storage.NEW and an ObjectId value of null.

newRef - new reference to store.

Returns:

true if the put was successful; false otherwise.

Throws:

IOException - the reference cannot be put due to a system error.

compareAndRemove

protected boolean compareAndRemove(Ref oldRef)
                            throws IOException

Description copied from class: DfsRefDatabase

Compare a reference, and delete if it matches.

Specified by:

compareAndRemove in class DfsRefDatabase

Parameters:

oldRef - the old reference information that was previously read.

Returns:

true if the remove was successful; false otherwise.

Throws:

IOException - the reference could not be removed due to a system error.