/// <inheritdoc />
public async Task <LockToken> RenewAsync(LockToken token, TimeSpan duration)
{
var table = await GetTableAsync();
var doc = new Document();
doc[ColumnNames.HolderId] = token.HolderId;
doc[ColumnNames.ResourceId] = token.ResourceId;
var expiry = DateTimeOffset.UtcNow.Add(duration);
doc[ColumnNames.LeaseExpiry] = expiry.ToString("O");
var expr = new Expression();
expr.ExpressionStatement = $"{ColumnNames.ResourceId} = :ID OR {ColumnNames.LeaseExpiry} < :NOW";
expr.ExpressionAttributeValues[":NOW"] = DateTimeOffset.UtcNow.ToString("O");
expr.ExpressionAttributeValues[":ID"] = token.ResourceId;
try
{
await table.PutItemAsync(doc, new PutItemOperationConfig()
{
ConditionalExpression = expr
});
return(token.WithNewExpiry(expiry));
}
catch (ConditionalCheckFailedException e)
{
return(null);
}
}
/// <inheritdoc />
public async Task ReleaseLockAsync(LockToken token)
{
var table = await GetTableAsync();
var doc = new Document();
doc[ColumnNames.HolderId] = token.HolderId;
doc[ColumnNames.ResourceId] = token.ResourceId;
doc[ColumnNames.LeaseExpiry] = token.LeaseExpiry.ToString("O");
await table.DeleteItemAsync(doc);
}
