/// <summary>
/// Return the stat of the node of the given path. Return null if no such a
/// node exists.
///
/// If the watch is non-null and the call is successful (no exception is thrown),
/// a watch will be left on the node with the given path. The watch will be
/// triggered by a successful operation that creates/delete the node or sets
/// the data on the node.
/// </summary>
/// <param name="path">The path.</param>
/// <param name="watcher">The watcher.</param>
/// <returns>the stat of the node of the given path; return null if no such a node exists.</returns>
public Stat Exists(string path, IWatcher watcher)
{
string clientPath = path;
PathUtils.ValidatePath(clientPath);
// the watch contains the un-chroot path
WatchRegistration wcb = null;
if (watcher != null)
{
wcb = new ExistsWatchRegistration(watchManager, watcher, clientPath);
}
string serverPath = PrependChroot(clientPath);
RequestHeader h = new RequestHeader();
h.Type = (int)OpCode.Exists;
ExistsRequest request = new ExistsRequest(serverPath, watcher != null);
SetDataResponse response = new SetDataResponse();
ReplyHeader r = cnxn.SubmitRequest(h, request, response, wcb);
if (r.Err != 0)
{
if (r.Err == (int)KeeperException.Code.NONODE)
{
return(null);
}
throw KeeperException.Create((KeeperException.Code)Enum.ToObject(typeof(KeeperException.Code), r.Err), clientPath);
}
return(response.Stat.Czxid == -1 ? null : response.Stat);
}
public async Task testNonExistingOpCode()
{
ZooKeeper zk = await createClient();
const string path = "/m1";
RequestHeader h = new RequestHeader();
h.set_Type(888); // This code does not exists
ExistsRequest request = new ExistsRequest();
request.setPath(path);
request.setWatch(false);
ExistsResponse response = new ExistsResponse();
ReplyHeader r = await zk.cnxn.submitRequest(h, request, response, null);
Assert.assertEquals(r.getErr(), (int)KeeperException.Code.UNIMPLEMENTED);
try {
await zk.existsAsync("/m1", false);
Assert.fail("The connection should have been closed");
}
catch (KeeperException.ConnectionLossException) {
}
}
/// <summary>
///
/// </summary>
/// <param name="request"></param>
/// <returns></returns>
internal static string GetExistsText(ExistsRequest request)
{
if (cache.TryGetValue(request, out var commandText) == false)
{
var statementBuilder = EnsureStatementBuilder(request.Connection, request.StatementBuilder);
commandText = statementBuilder.CreateExists(new QueryBuilder(),
request.Name,
request.Where,
request.Hints);
cache.TryAdd(request, commandText);
}
return(commandText);
}
/// <summary>
/// Checks if username exists
/// </summary>
/// <param name="exists"><see cref="ExistsRequest"/></param>
/// <returns>True if username already exists</returns>
public bool Exists(ExistsRequest exists)
{
using (MySqlConnection connection = WebApiConfig.Connection())
using (MySqlCommand command = new MySqlCommand($"SELECT * FROM `{exists.TableName}` WHERE {exists.Column} = \"{exists.Value}\"", connection))
{
connection.Open();
using (MySqlDataReader reader = command.ExecuteReader())
{
if (reader.Read())
{
return(true);
}
return(false);
}
}
}
public override Task <ExistsResponse> Exists(ExistsRequest request, ServerCallContext context)
{
if (File.Exists(request.Path))
{
return(Task.FromResult(new ExistsResponse {
Exists = true, Kind = Kind.File
}));
}
if (Directory.Exists(request.Path))
{
return(Task.FromResult(new ExistsResponse {
Exists = true, Kind = Kind.Directory
}));
}
return(Task.FromResult(new ExistsResponse {
Exists = false
}));
}
public async Task testNonExistingOpCode()
{
DisconnectedWatcher disconnectedWatcher = new DisconnectedWatcher();
ZooKeeper zk = await createClient(disconnectedWatcher);
const string path = "/m1";
RequestHeader h = new RequestHeader();
h.set_Type(888); // This code does not exists
ExistsRequest request = new ExistsRequest();
request.setPath(path);
request.setWatch(false);
ExistsResponse response = new ExistsResponse();
ReplyHeader r = await zk.cnxn.submitRequest(h, request, response, null);
Assert.assertEquals(r.getErr(), (int)KeeperException.Code.UNIMPLEMENTED);
// Sending a nonexisting opcode should cause the server to disconnect
Assert.assertTrue("failed to disconnect",
await disconnectedWatcher.getTask().WithTimeout(5000));
}
public Task <ExistsResult> ExistsAsync(ExistsRequest request) => throw new NotSupportedException();
/// <inheritdoc cref="IZooKeeperClient.ExistsAsync"/> public static ExistsResult Exists(this IZooKeeperClient client, ExistsRequest request) => client.ExistsAsync(request).GetAwaiter().GetResult();
/// <inheritdoc /> public Task <ExistsResult> ExistsAsync(ExistsRequest request) => ExecuteOperation(new ExistsOperation(request, watcherWrapper));
