public async Task <IReadOnlyCollection <ObjectVersionRecord> > GetObjectVersions(long id, string initialVersionId)
{
var objectDescriptors = new List <ObjectDescriptor>();
async Task <(bool IsTruncated, int NextVersionIndex, string NextVersionIdMarker)> ListVersions(int nextVersionIndex, string nextVersionIdMarker)
{
await _distributedLockManager.EnsureLockNotExists(id);
var response = await _s3Client.ListVersionsAsync(
new ListVersionsRequest
{
BucketName = _bucketName,
Prefix = id.AsS3ObjectKey(Tokens.ObjectPostfix),
VersionIdMarker = nextVersionIdMarker
});
var nonDeletedVersions = response.Versions.FindAll(x => !x.IsDeleteMarker);
nextVersionIndex += nonDeletedVersions.Count;
var initialVersionIdReached = false;
var versionInfos = nonDeletedVersions
.Aggregate(
new List <(string VersionId, DateTime LastModified)>(),
(list, next) =>
{
initialVersionIdReached = initialVersionIdReached ||
!string.IsNullOrEmpty(initialVersionId) &&
initialVersionId.Equals(next.VersionId, StringComparison.OrdinalIgnoreCase);
if (!initialVersionIdReached)
{
list.Add((next.VersionId, next.LastModified));
}
return(list);
});
var descriptors = new ObjectDescriptor[versionInfos.Count];
var partitioner = Partitioner.Create(versionInfos);
var tasks = partitioner.GetOrderablePartitions(_degreeOfParallelism)
.Select(async partition =>
{
while (partition.MoveNext())
{
var index = partition.Current.Key;
var versionInfo = partition.Current.Value;
descriptors[index] = await GetObjectDescriptor(id, versionInfo.VersionId);
}
});
await Task.WhenAll(tasks);
objectDescriptors.AddRange(descriptors);
return(!initialVersionIdReached && response.IsTruncated, nextVersionIndex, response.NextVersionIdMarker);
}
var result = await ListVersions(0, null);
if (objectDescriptors.Count == 0)
{
throw new ObjectNotFoundException($"Object '{id}' not found.");
}
while (result.IsTruncated)
{
result = await ListVersions(result.NextVersionIndex, result.NextVersionIdMarker);
}
var maxVersionIndex = result.NextVersionIndex;
var records = new ObjectVersionRecord[objectDescriptors.Count];
for (var index = 0; index < objectDescriptors.Count; ++index)
{
var descriptor = objectDescriptors[index];
records[index] = new ObjectVersionRecord(
descriptor.Id,
descriptor.VersionId,
--maxVersionIndex,
descriptor.LastModified,
new AuthorInfo(descriptor.Metadata.Author, descriptor.Metadata.AuthorLogin, descriptor.Metadata.AuthorLogin),
descriptor.Properties,
descriptor.Elements.Select(x => new ObjectVersionRecord.ElementRecord(x.TemplateCode, x.Value)).ToList(),
descriptor.Metadata.ModifiedElements);
}
return(records);
}
