public virtual async Task <List <BlobChangeFeedEvent> > GetPage(
bool async,
int?pageSize,
CancellationToken cancellationToken = default)
{
List <BlobChangeFeedEvent> changeFeedEventList = new List <BlobChangeFeedEvent>();
if (!HasNext())
{
throw new InvalidOperationException("Segment doesn't have any more events");
}
int i = 0;
while (i < pageSize && _shards.Count > 0)
{
// If this Shard is finished, skip it.
if (_finishedShards.Contains(_shardIndex))
{
_shardIndex++;
if (_shardIndex == _shards.Count)
{
_shardIndex = 0;
}
continue;
}
Shard currentShard = _shards[_shardIndex];
BlobChangeFeedEvent changeFeedEvent = await currentShard.Next(async, cancellationToken).ConfigureAwait(false);
changeFeedEventList.Add(changeFeedEvent);
// If the current shard is completed, remove it from _shards
if (!currentShard.HasNext())
{
_finishedShards.Add(_shardIndex);
}
i++;
_shardIndex++;
if (_shardIndex >= _shards.Count)
{
_shardIndex = 0;
}
// If all the Shards are finished, we need to break out early.
if (_finishedShards.Count == _shards.Count)
{
break;
}
}
return(changeFeedEventList);
}
#pragma warning disable CA1822 // Does not acces instance data can be marked static.
public virtual async Task <Segment> BuildSegment(
#pragma warning restore CA1822 // Can't mock static methods in MOQ.
bool async,
string manifestPath,
SegmentCursor cursor = default)
{
// Models we need for later
List <Shard> shards = new List <Shard>();
DateTimeOffset dateTime = BlobChangeFeedExtensions.ToDateTimeOffset(manifestPath).Value;
// Download segment manifest
BlobClient blobClient = _containerClient.GetBlobClient(manifestPath);
BlobDownloadInfo blobDownloadInfo;
if (async)
{
blobDownloadInfo = await blobClient.DownloadAsync().ConfigureAwait(false);
}
else
{
blobDownloadInfo = blobClient.Download();
}
// Parse segment manifest
JsonDocument jsonManifest;
if (async)
{
jsonManifest = await JsonDocument.ParseAsync(blobDownloadInfo.Content).ConfigureAwait(false);
}
else
{
jsonManifest = JsonDocument.Parse(blobDownloadInfo.Content);
}
foreach (JsonElement shardJsonElement in jsonManifest.RootElement.GetProperty("chunkFilePaths").EnumerateArray())
{
string shardPath = shardJsonElement.ToString().Substring("$blobchangefeed/".Length);
var shardCursor = cursor?.ShardCursors?.Find(x => x.CurrentChunkPath.StartsWith(shardPath, StringComparison.InvariantCulture));
Shard shard = await _shardFactory.BuildShard(
async,
shardPath,
shardCursor)
.ConfigureAwait(false);
if (shard.HasNext())
{
shards.Add(shard);
}
}
int shardIndex = 0;
string currentShardPath = cursor?.CurrentShardPath;
if (!string.IsNullOrWhiteSpace(currentShardPath))
{
shardIndex = shards.FindIndex(s => s.ShardPath == currentShardPath);
if (shardIndex < 0)
{
// Either shard doesn't exist or cursor is pointing to end of shard. So start from beginning.
shardIndex = 0;
}
}
return(new Segment(
shards,
shardIndex,
dateTime,
manifestPath));
}