/// <summary>
/// Gets the versions.
/// </summary>
/// <returns>
/// Returns an enumerable with the MongoDb versions.
/// </returns>
/// <exception cref="NAMEException">Thrown when an unexpected exception happens.</exception>
public override async Task <IEnumerable <DependencyVersion> > GetVersions()
{
var versions = new List <DependencyVersion>();
if (!this.connectionStringProvider.TryGetConnectionString(out string connectionString))
{
throw new ConnectionStringNotFoundException(this.connectionStringProvider.ToString());
}
var connectionStringBuilder = new MongoConnectionStringBuilder(connectionString);
byte[] message = this.CreateServerStatusMessagePayload(connectionStringBuilder);
foreach (var mongoEndpoint in connectionStringBuilder.Servers)
{
using (var client = await this.OpenTcpClient(mongoEndpoint.Host, mongoEndpoint.Port, SupportedDependencies.MongoDb.ToString()))
{
await client.GetStream().WriteAsync(message, 0, message.Length, default(CancellationToken)).ConfigureAwait(false);
await Task.Delay(100).ConfigureAwait(false);
BSONObject obj = ExtractServerStatusFromResponse(client);
versions.Add(DependencyVersionParser.Parse(obj["version"].stringValue, false));
}
}
return(versions);
}
private byte[] CreateServerStatusMessagePayload(MongoConnectionStringBuilder connectionStringBuilder)
{
byte[] message;
int commandLength;
//Write the message first because we need the it's length
using (var commandMemoryStream = new MemoryStream())
using (var commandWriter = new BinaryWriter(commandMemoryStream, new UTF8Encoding(), true))
{
//Query options
commandWriter.Write(0);
//Collection name
commandWriter.Write($"{connectionStringBuilder.Database}.$cmd".ToArray());
//cstring's require a \x00 at the end.
commandWriter.Write('\x00');
//Number to skip
commandWriter.Write(0);
//Number to return
commandWriter.Write(-1);
var commandBSON = new BSONObject
{
["serverStatus"] = 1.0
};
commandWriter.Write(SimpleBSON.Dump(commandBSON));
commandWriter.Flush();
commandLength = (int)commandMemoryStream.Length;
message = new byte[16 + commandLength];
Array.Copy(commandMemoryStream.ToArray(), 0, message, 16, commandLength);
}
using (var messageMemoryStream = new MemoryStream(message))
using (var completeMessageWriter = new BinaryWriter(messageMemoryStream, new UTF8Encoding(), true))
{
//Message length
completeMessageWriter.Write(16 + commandLength);
//Request Id
completeMessageWriter.Write(0);
//Response To
completeMessageWriter.Write(0);
//Operation Code
completeMessageWriter.Write(2004);
completeMessageWriter.Flush();
}
return(message);
}
