/// <summary>
/// Allocates a new value and produces reference to it.
/// </summary>
/// <param name="value">Value to allocate</param>
/// <returns>Reference to allocated value</returns>
public DbItemReference AllocateNew(TValue value)
{
var valueBytes = _valueSerializer.Serialize(value);
return(IsVersioningEnabled
? VersionedRecord.CreateNew(valueBytes, DataTankerTransaction.Current.Id, _memoryManager)
: _memoryManager.Allocate(valueBytes));
}
public void RecordIsVisibleToItsCreator()
{
var memoryManager = new MemoryManager();
var content = new byte[] { 0, 1 };
var recordReference = VersionedRecord.CreateNew(content, 0, memoryManager);
var snapshotData = new SnapshotData(new int[] { });
var record = new VersionedRecord(memoryManager.Get(recordReference).RawData, memoryManager, snapshotData);
Assert.IsTrue(record.HasVisibleVersionTo(0));
}
private DbItemReference GetVersionReferenceByRecordReference(DbItemReference reference)
{
if (IsVersioningEnabled)
{
var record = new VersionedRecord(_memoryManager.Get(reference).RawData, _memoryManager, SnapshotData);
if (record.HasVisibleVersionTo(DataTankerTransaction.Current.Id))
{
reference = record.GetMatchingVersionReference(DataTankerTransaction.Current.Id);
}
}
return(reference);
}
public void VersionCreatedByCommitedTransactionIsVisible()
{
var memoryManager = new MemoryManager();
var content = new byte[] { 0, 1 };
var recordReference = VersionedRecord.CreateNew(content, 0, memoryManager);
var snapshotData = new SnapshotData(new[] { 0 });
var record = new VersionedRecord(memoryManager.Get(recordReference).RawData, memoryManager, snapshotData);
Assert.IsTrue(record.HasVisibleVersionTo(1));
}
public void ExpireOfUpdatedRecordProduceWriteConflict()
{
var memoryManager = new MemoryManager();
var content = new byte[] { 0, 1 };
var recordReference = VersionedRecord.CreateNew(content, 0, memoryManager);
var snapshotData = new SnapshotData(new int[] { });
var record = new VersionedRecord(memoryManager.Get(recordReference).RawData, memoryManager, snapshotData);
record.Update(new byte[] { 2, 3 }, 0); // zero transaction updates the record
Assert.That(() => record.Expire(1), Throws.Exception.TypeOf <WriteConflictException>()); // first transaction trying to expire it
}
/// <summary>
/// Fetches value by its reference.
/// </summary>
/// <param name="reference">Reference to the value</param>
/// <returns>The instance of value</returns>
public TValue Fetch(DbItemReference reference)
{
var item = _memoryManager.Get(reference);
if (IsVersioningEnabled)
{
var record = new VersionedRecord(item.RawData, _memoryManager, SnapshotData);
if (record.HasVisibleVersionTo(DataTankerTransaction.Current.Id))
{
item = record.GetMatchingVersion(DataTankerTransaction.Current.Id);
}
}
return(_valueSerializer.Deserialize(item.RawData));
}
public void ExpiredVersionIsInvisible()
{
var memoryManager = new MemoryManager();
var content = new byte[] { 0, 1 };
var recordReference = VersionedRecord.CreateNew(content, 0, memoryManager);
var snapshotData = new SnapshotData(new int[] { });
var record = new VersionedRecord(memoryManager.Get(recordReference).RawData, memoryManager, snapshotData);
record.Expire(0);
Assert.IsFalse(record.HasVisibleVersionTo(0));
}
public void UpdateRecordCreatedByCommitedTransaction()
{
var memoryManager = new MemoryManager();
var content = new byte[] { 0, 1 };
var newContent = new byte[] { 2, 3 };
var recordReference = VersionedRecord.CreateNew(content, 0, memoryManager);
var snapshotData = new SnapshotData(new[] { 0 }); // zero transaction is commited
var record = new VersionedRecord(memoryManager.Get(recordReference).RawData, memoryManager, snapshotData);
record.Update(newContent, 1);
Assert.IsTrue(newContent.SequenceEqual(record.GetMatchingVersion(1).RawData));
}
public void UpdateProduceNewVersion()
{
var memoryManager = new MemoryManager();
var oldContent = new byte[] { 0, 1 };
var newContent = new byte[] { 2, 3 };
var recordReference = VersionedRecord.CreateNew(oldContent, 0, memoryManager);
var snapshotData = new SnapshotData(new int[] { });
var record = new VersionedRecord(memoryManager.Get(recordReference).RawData, memoryManager, snapshotData);
record.Update(newContent, 0);
Assert.IsTrue(record.HasVisibleVersionTo(0));
Assert.IsTrue(newContent.SequenceEqual(record.GetMatchingVersion(0).RawData));
}
public void ConcurrentlyRunningTransactionsViewTheirOwnVersions()
{
var memoryManager = new MemoryManager();
var content = new byte[] { 0, 1 };
var newContent = new byte[] { 2, 3 };
var recordReference = VersionedRecord.CreateNew(content, 0, memoryManager);
var snapshotData = new SnapshotData(new[] { 0 });
var record = new VersionedRecord(memoryManager.Get(recordReference).RawData, memoryManager, snapshotData);
var newReference = record.InsertOrUpdate(newContent, 1);
record = new VersionedRecord(memoryManager.Get(newReference).RawData, memoryManager, snapshotData);
Assert.IsTrue(newContent.SequenceEqual(record.GetMatchingVersion(1).RawData));
Assert.IsTrue(content.SequenceEqual(record.GetMatchingVersion(2).RawData));
}
public void UpdateRecordExpiredByRolledBackTransaction()
{
var memoryManager = new MemoryManager();
var content = new byte[] { 0, 1 };
var newContent = new byte[] { 2, 3 };
var recordReference = VersionedRecord.CreateNew(content, 0, memoryManager);
var snapshotData = new SnapshotData(new[] { 0 });
var record = new VersionedRecord(memoryManager.Get(recordReference).RawData, memoryManager, snapshotData);
var newReference = record.Expire(1);
snapshotData = new SnapshotData(new[] { 0 }, new[] { 1 });
record = new VersionedRecord(memoryManager.Get(newReference).RawData, memoryManager, snapshotData);
record.Update(newContent, 2);
Assert.IsTrue(newContent.SequenceEqual(record.GetMatchingVersion(2).RawData));
}
public void ResurrectRecordExpiredByCommitedTransaction()
{
var memoryManager = new MemoryManager();
var content = new byte[] { 0, 1 };
var newContent = new byte[] { 2, 3 };
var recordReference = VersionedRecord.CreateNew(content, 0, memoryManager);
var snapshotData = new SnapshotData(new int[] { });
var record = new VersionedRecord(memoryManager.Get(recordReference).RawData, memoryManager, snapshotData);
var newReference = record.Expire(0);
snapshotData = new SnapshotData(new[] { 0 });
record = new VersionedRecord(memoryManager.Get(newReference).RawData, memoryManager, snapshotData);
record.Insert(newContent, 1);
Assert.IsTrue(newContent.SequenceEqual(record.GetMatchingVersion(1).RawData));
}
