public CopyStateStream(
long upToSequenceNumber,
IOperationDataStream copyContext,
ProgressVector localProgress,
LogFile operationLog,
IReplicationNotifier replicationNotifier,
Logger logger,
Serializer serializer)
{
this.upToSequenceNumber = upToSequenceNumber;
this.copyContext = copyContext;
this.localProgress = localProgress;
this.logger = logger;
this.serializer = serializer;
this.log = operationLog;
this.replicationNotifier = replicationNotifier;
this.records = operationLog.GetAllRecords().GetEnumerator();
}
public CopyStateStream(
long upToSequenceNumber,
IOperationDataStream copyContext,
ProgressVector localProgress,
LogFile operationLog,
IReplicationNotifier replicationNotifier,
Logger logger,
Serializer serializer)
{
this.upToSequenceNumber = upToSequenceNumber;
this.copyContext = copyContext;
this.localProgress = localProgress;
this.logger = logger;
this.serializer = serializer;
this.log = operationLog;
this.replicationNotifier = replicationNotifier;
this.records = operationLog.GetAllRecords().GetEnumerator();
}
private async Task <ProgressVector> GetRemoteReplicaProgress()
{
var result = new ProgressVector();
do
{
var copyContextCancellationToken = new CancellationTokenSource(TimeSpan.FromMinutes(5)).Token;
var context = await this.copyContext.GetNextAsync(copyContextCancellationToken);
if (context == null)
{
break;
}
foreach (var item in context)
{
result.Update(this.serializer.Deserialize <ProgressIndicator>(item));
}
}while (true);
return(result);
}
public CopyContextStream(ProgressVector progressVector, Logger logger, Serializer serializer)
{
this.logger = logger;
this.serializer = serializer;
this.progressVector = progressVector.GetEnumerator();
}
public async Task<OperationData> GetNextAsync(CancellationToken cancellationToken)
{
// Get the progress of the remote replica.
if (this.catchUpProgressVector == null)
{
var remoteProgress = await this.GetRemoteReplicaProgress();
this.catchUpProgressVector = new ProgressVector(this.localProgress.Excluding(remoteProgress));
this.logger.Log(
"CopyStateStream:\n"
+ $"Local progress: {this.localProgress} (& up to LSN {this.upToSequenceNumber})\n"
+ $"Remote progress: {remoteProgress}\n" + $"Delta Progress: {this.catchUpProgressVector}");
}
// Nothing to copy.
if (this.upToSequenceNumber == 0)
{
return null;
}
// Find the first entry which needs to be replicated
var result = default(OperationData);
var totalSize = 0;
// Wait for the required records to become available.
this.hasRecord = this.records.MoveNext();
while (this.hasRecord)
{
var rawRecord = this.records.Current;
var record = this.serializer.Deserialize<Record>(rawRecord);
var operation = record as OperationCommittedRecord;
if (operation == null)
{
this.logger.Log(
$"CopyStateStream: {record} is not an {nameof(OperationCommittedRecord)}, it is an {record.GetType()}.");
this.hasRecord = this.records.MoveNext();
continue;
}
var currentVersion = operation.Version;
var currentLsn = currentVersion.LogSequenceNumber;
if (currentLsn > this.upToSequenceNumber)
{
break;
}
// Only return records which were actually committed.
if (!this.catchUpProgressVector.IncludesVersionInPreviousEpoch(currentVersion)
&& this.catchUpProgressVector.Current.Epoch != currentVersion.Epoch)
{
#warning we need a bucket load of tests around this to motivate correctness. How is the 'zero' epoch handled? Does such a thing even exist?
/*this.logger.Log(
$"CopyStateStream: {currentVersion} is not in the catchup vector or current epoch ({this.catchUpProgressVector.Current.Epoch.ToDisplayString()})");*/
this.hasRecord = this.records.MoveNext();
continue;
}
if (result == null)
{
this.lowestLsn = currentLsn;
}
this.highestLsn = this.highestLsn > currentLsn ? this.highestLsn : currentLsn;
// Copy the payload into the result.
var data = this.serializer.Serialize(record);
if (result == null)
{
result = new OperationData(data);
}
else
{
result.Add(data);
}
this.hasRecord = this.records.MoveNext();
// If a sequence number which has not yet been committed has been requested, wait for that before continuing.
if (!this.hasRecord && this.highestLsn != this.upToSequenceNumber)
{
await this.WaitForCommit(rawRecord.SequenceNumber, cancellationToken);
}
// Send only a certain amount of data at a time.
totalSize += data.Count;
if (totalSize > ResultCutoffLength)
{
break;
}
}
this.logger.Log(
result == null
? "Completed copying state"
: $"CopyStateStream.GetNextAsync returning {result.Count} records, from LSN {this.lowestLsn} to {this.highestLsn}");
return result;
}
private async Task<ProgressVector> GetRemoteReplicaProgress()
{
var result = new ProgressVector();
do
{
var copyContextCancellationToken = new CancellationTokenSource(TimeSpan.FromMinutes(5)).Token;
var context = await this.copyContext.GetNextAsync(copyContextCancellationToken);
if (context == null)
{
break;
}
foreach (var item in context)
{
result.Update(this.serializer.Deserialize<ProgressIndicator>(item));
}
}
while (true);
return result;
}
public CopyContextStream(ProgressVector progressVector, Logger logger, Serializer serializer)
{
this.logger = logger;
this.serializer = serializer;
this.progressVector = progressVector.GetEnumerator();
}
public async Task <OperationData> GetNextAsync(CancellationToken cancellationToken)
{
// Get the progress of the remote replica.
if (this.catchUpProgressVector == null)
{
var remoteProgress = await this.GetRemoteReplicaProgress();
this.catchUpProgressVector = new ProgressVector(this.localProgress.Excluding(remoteProgress));
this.logger.Log(
"CopyStateStream:\n"
+ $"Local progress: {this.localProgress} (& up to LSN {this.upToSequenceNumber})\n"
+ $"Remote progress: {remoteProgress}\n" + $"Delta Progress: {this.catchUpProgressVector}");
}
// Nothing to copy.
if (this.upToSequenceNumber == 0)
{
return(null);
}
// Find the first entry which needs to be replicated
var result = default(OperationData);
var totalSize = 0;
// Wait for the required records to become available.
this.hasRecord = this.records.MoveNext();
while (this.hasRecord)
{
var rawRecord = this.records.Current;
var record = this.serializer.Deserialize <Record>(rawRecord);
var operation = record as OperationCommittedRecord;
if (operation == null)
{
this.logger.Log(
$"CopyStateStream: {record} is not an {nameof(OperationCommittedRecord)}, it is an {record.GetType()}.");
this.hasRecord = this.records.MoveNext();
continue;
}
var currentVersion = operation.Version;
var currentLsn = currentVersion.LogSequenceNumber;
if (currentLsn > this.upToSequenceNumber)
{
break;
}
// Only return records which were actually committed.
if (!this.catchUpProgressVector.IncludesVersionInPreviousEpoch(currentVersion) &&
this.catchUpProgressVector.Current.Epoch != currentVersion.Epoch)
{
#warning we need a bucket load of tests around this to motivate correctness. How is the 'zero' epoch handled? Does such a thing even exist?
/*this.logger.Log(
* $"CopyStateStream: {currentVersion} is not in the catchup vector or current epoch ({this.catchUpProgressVector.Current.Epoch.ToDisplayString()})");*/
this.hasRecord = this.records.MoveNext();
continue;
}
if (result == null)
{
this.lowestLsn = currentLsn;
}
this.highestLsn = this.highestLsn > currentLsn ? this.highestLsn : currentLsn;
// Copy the payload into the result.
var data = this.serializer.Serialize(record);
if (result == null)
{
result = new OperationData(data);
}
else
{
result.Add(data);
}
this.hasRecord = this.records.MoveNext();
// If a sequence number which has not yet been committed has been requested, wait for that before continuing.
if (!this.hasRecord && this.highestLsn != this.upToSequenceNumber)
{
await this.WaitForCommit(rawRecord.SequenceNumber, cancellationToken);
}
// Send only a certain amount of data at a time.
totalSize += data.Count;
if (totalSize > ResultCutoffLength)
{
break;
}
}
this.logger.Log(
result == null
? "Completed copying state"
: $"CopyStateStream.GetNextAsync returning {result.Count} records, from LSN {this.lowestLsn} to {this.highestLsn}");
return(result);
}