public void ReleaseResource(IDocumentStore store, string resourceName, long index)
{
CompareExchangeResult <SharedResource> deleteResult
= store.Operations.Send(new DeleteCompareExchangeValueOperation <SharedResource>(resourceName, index));
// We have 2 options here:
// deleteResult.Successful is true - we managed to release resource
// deleteResult.Successful is false - someone else took the look due to timeout
}
public async Task Sample()
{
using (var store = new DocumentStore())
{
#region email
string email = "*****@*****.**";
User user = new User
{
Email = email
};
using (IDocumentSession session = store.OpenSession())
{
session.Store(user);
// At this point, the user document has an Id assigned
// Try to reserve a new user email
// Note: This operation takes place outside of the session transaction,
// It is a cluster-wide reservation
CompareExchangeResult <string> cmpXchgResult
= store.Operations.Send(
new PutCompareExchangeValueOperation <string>("emails/" + email, user.Id, 0));
if (cmpXchgResult.Successful == false)
{
throw new Exception("Email is already in use");
}
// At this point we managed to reserve/save the user email -
// The document can be saved in SaveChanges
session.SaveChanges();
}
#endregion
#region query_cmpxchg
using (IDocumentSession session = store.OpenSession())
{
var query = from u in session.Query <User>()
where u.Email == RavenQuery.CmpXchg <string>("emails/[email protected]")
select u;
var q = session.Advanced
.DocumentQuery <User>()
.WhereEquals("Email", CmpXchg.Value("emails/[email protected]"));
}
#endregion
}
}
public IActionResult Run(RunParams runParams)
{
string cmpXchgKey = runParams.CmpXchgKey ?? "*****@*****.**";
string cmpXchgValue = runParams.CmpXchgValue ?? "employee/1-A";
string result = null;
#region Demo
#region Step_1
var putCmpXchgOperation =
new PutCompareExchangeValueOperation <string>(cmpXchgKey, cmpXchgValue, 0);
CompareExchangeResult <string> putCmpXchgResult =
DocumentStoreHolder.Store.Operations.Send(putCmpXchgOperation);
#endregion
#region Step_2
var success = putCmpXchgResult.Successful;
var putValue = putCmpXchgResult.Value;
var putVersion = putCmpXchgResult.Index;
if (success == false)
{
result = "Key already exists";
}
#endregion
#region Step_3
var getCmpXchgOperation =
new GetCompareExchangeValueOperation <string>(cmpXchgKey);
CompareExchangeValue <string> getCmpXchgResult =
DocumentStoreHolder.Store.Operations.Send(getCmpXchgOperation);
#endregion
#region Step_4
var key = getCmpXchgResult.Key;
var currentValue = getCmpXchgResult.Value;
var currentValueVersion = getCmpXchgResult.Index;
var currentMetadata = getCmpXchgResult.Metadata;
#endregion
#endregion
result = result ?? $"Created a new Compare-Exchange Key: {key}, Value: {currentValue}, Value Version: {currentValueVersion}";
return(Ok(result));
}
public async Task SubscriptionsWorksWithCompareExchange()
{
using (var store = GetDocumentStore())
{
string userId;
string cmpxValueOriginal;
using (var session = store.OpenSession())
{
User user = new User
{
Name = "foobar"
};
session.Store(user);
userId = session.Advanced.GetDocumentId(user);
// Try to reserve a new user email
// Note: This operation takes place outside of the session transaction,
// It is a cluster-wide reservation
cmpxValueOriginal = "His name is " + user.Name;
CompareExchangeResult <string> cmpXchgResult
= store.Operations.Send(
new PutCompareExchangeValueOperation <string>(user.Id, cmpxValueOriginal, 0));
session.SaveChanges();
}
var subsId = store.Subscriptions.Create <User>(new Raven.Client.Documents.Subscriptions.SubscriptionCreationOptions <User>()
{
Projection = x => new
{
Foo = RavenQuery.CmpXchg <string>(userId),
x.AddressId
}
});
string cmpxValue = string.Empty;
var subsWorker = store.Subscriptions.GetSubscriptionWorker(new Raven.Client.Documents.Subscriptions.SubscriptionWorkerOptions(subsId)
{
CloseWhenNoDocsLeft = true
});
await Assert.ThrowsAsync <SubscriptionClosedException>(async() =>
await subsWorker.Run(x =>
{
cmpxValue = x.Items[0].RawResult["Foo"].ToString();
}));
Assert.Equal(cmpxValue, cmpxValueOriginal);
}
}
public long LockResource(IDocumentStore store, string resourceName, TimeSpan duration)
{
while (true)
{
DateTime now = DateTime.UtcNow;
SharedResource resource = new SharedResource
{
ReservedUntil = now.Add(duration)
};
CompareExchangeResult <SharedResource> saveResult = store.Operations.Send(
new PutCompareExchangeValueOperation <SharedResource>(resourceName, resource, 0));
if (saveResult.Successful)
{
// resourceName wasn't present - we managed to reserve
return(saveResult.Index);
}
// At this point, Put operation failed - someone else owns the lock or lock time expired
if (saveResult.Value.ReservedUntil < now)
{
// Time expired - Update the existing key with the new value
CompareExchangeResult <SharedResource> takeLockWithTimeoutResult = store.Operations.Send(
new PutCompareExchangeValueOperation <SharedResource>(resourceName, resource, saveResult.Index));
if (takeLockWithTimeoutResult.Successful)
{
return(takeLockWithTimeoutResult.Index);
}
}
// Wait a little bit and retry
Thread.Sleep(20);
}
}
public async Task CreateFullAndIncrementalBackupWithCompareExchangeInTheMiddle()
{
var backupPath = NewDataPath(suffix: "BackupFolder");
using (var store = GetDocumentStore())
{
using (var session = store.OpenSession())
{
session.Store(new User
{
Name = "Toli"
}, "users/1");
session.SaveChanges();
}
var config = new PeriodicBackupConfiguration
{
LocalSettings = new LocalSettings
{
FolderPath = backupPath
},
Name = "full",
FullBackupFrequency = "* */6 * * *",
BackupType = BackupType.Backup
};
var result = await store.Maintenance.SendAsync(new UpdatePeriodicBackupOperation(config));
var documentDatabase = (await GetDocumentDatabaseInstanceFor(store));
RunBackup(result.TaskId, documentDatabase, true, store);
CompareExchangeResult <string> compareExchangeResult
= store.Operations.Send(
new PutCompareExchangeValueOperation <string>("users/1", "Mitzi", 0));
config.IncrementalBackupFrequency = "* */2 * * *";
config.TaskId = result.TaskId;
result = await store.Maintenance.SendAsync(new UpdatePeriodicBackupOperation(config));
RunBackup(result.TaskId, documentDatabase, false, store);
var backupDirectory = Directory.GetDirectories(backupPath).First();
var databaseName = GetDatabaseName() + "restore";
RestoreBackupConfiguration config2 = new RestoreBackupConfiguration()
{
BackupLocation = backupDirectory,
DatabaseName = databaseName,
LastFileNameToRestore = Directory.GetFiles(backupDirectory).Last()
};
RestoreBackupOperation restoreOperation = new RestoreBackupOperation(config2);
store.Maintenance.Server.Send(restoreOperation)
.WaitForCompletion();
using (var store2 = GetDocumentStore(new Options()
{
CreateDatabase = false,
ModifyDatabaseName = s => databaseName
}))
{
using (var session = store2.OpenSession())
{
var doc = session.Load <User>("users/1");
Assert.NotNull(doc);
};
CompareExchangeValue <string> readResult =
store2.Operations.Send(new GetCompareExchangeValueOperation <string>("users/1"));
Assert.Equal("Mitzi", readResult.Value);
};
}
}
public CompareExchange()
{
using (var store = new DocumentStore())
{
{
#region get_1
CompareExchangeValue <long> readResult =
store.Operations.Send(new GetCompareExchangeValueOperation <long>("NextClientId"));
long value = readResult.Value;
#endregion
}
{
#region get_2
CompareExchangeValue <User> readResult =
store.Operations.Send(new GetCompareExchangeValueOperation <User>("AdminUser"));
User admin = readResult.Value;
#endregion
}
{
#region get_list_2
Dictionary <string, CompareExchangeValue <string> > compareExchangeValues
= store.Operations.Send(
new GetCompareExchangeValuesOperation <string>(new[] { "Key-1", "Key-2" }));
#endregion
}
{
#region get_list_3
// Get values for keys that have the common prefix 'users'
// Retrieve maximum 20 entries
Dictionary <string, CompareExchangeValue <User> > compareExchangeValues
= store.Operations.Send(new GetCompareExchangeValuesOperation <User>("users", 0, 20));
#endregion
}
{
#region put_1
CompareExchangeResult <string> compareExchangeResult
= store.Operations.Send(
new PutCompareExchangeValueOperation <string>("Emails/[email protected]", "users/123", 0));
bool successful = compareExchangeResult.Successful;
// If successfull is true: then Key '*****@*****.**' now has the value of "users/123"
#endregion
}
{
#region put_2
// Get existing value
CompareExchangeValue <User> readResult =
store.Operations.Send(
new GetCompareExchangeValueOperation <User>("AdminUser"));
readResult.Value.Age++;
// Update value
CompareExchangeResult <User> saveResult
= store.Operations.Send(
new PutCompareExchangeValueOperation <User>("AdminUser", readResult.Value, readResult.Index));
// The save result is successful only if 'index' wasn't changed between the read and write operations
bool saveResultSuccessful = saveResult.Successful;
#endregion
}
{
#region delete_1
// First, get existing value
CompareExchangeValue <User> readResult =
store.Operations.Send(
new GetCompareExchangeValueOperation <User>("AdminUser"));
// Delete the key - use the index received from the 'Get' operation
CompareExchangeResult <User> deleteResult
= store.Operations.Send(
new DeleteCompareExchangeValueOperation <User>("AdminUser", readResult.Index));
// The delete result is successful only if the index has not changed between the read and delete operations
bool deleteResultSuccessful = deleteResult.Successful;
#endregion
}
}
}
public CompareExchange()
{
using (var store = new DocumentStore())
{
{
#region get_1
CompareExchangeValue <long> readResult =
store.Operations.Send(new GetCompareExchangeValueOperation <long>("NextClientId"));
long value = readResult.Value;
#endregion
}
{
#region get_2
CompareExchangeValue <User> readResult =
store.Operations.Send(new GetCompareExchangeValueOperation <User>("AdminUser"));
User admin = readResult.Value;
#endregion
}
/*{ This overload is no longer available
#region get_list_2
* Dictionary<string, CompareExchangeValue<string>> compareExchangeValues
* = store.Operations.Send(
* new GetCompareExchangeValuesOperation<string>(new[] { "Key-1", "Key-2" }));
#endregion
* }*/
{
#region get_list_3
// Get values for keys that have the common prefix 'users'
// Retrieve maximum 20 entries
Dictionary <string, CompareExchangeValue <User> > compareExchangeValues
= store.Operations.Send(new GetCompareExchangeValuesOperation <User>("users", 0, 20));
#endregion
}
{
#region put_1
CompareExchangeResult <string> compareExchangeResult
= store.Operations.Send(
new PutCompareExchangeValueOperation <string>("Emails/[email protected]", "users/123", 0));
bool successful = compareExchangeResult.Successful;
// If successfull is true: then Key '*****@*****.**' now has the value of "users/123"
#endregion
}
{
#region put_2
// Get existing value
CompareExchangeValue <User> readResult =
store.Operations.Send(
new GetCompareExchangeValueOperation <User>("AdminUser"));
readResult.Value.Age++;
// Update value
CompareExchangeResult <User> saveResult
= store.Operations.Send(
new PutCompareExchangeValueOperation <User>("AdminUser", readResult.Value, readResult.Index));
// The save result is successful only if 'index' wasn't changed between the read and write operations
bool saveResultSuccessful = saveResult.Successful;
#endregion
}
{
#region delete_1
// First, get existing value
CompareExchangeValue <User> readResult =
store.Operations.Send(
new GetCompareExchangeValueOperation <User>("AdminUser"));
// Delete the key - use the index received from the 'Get' operation
CompareExchangeResult <User> deleteResult
= store.Operations.Send(
new DeleteCompareExchangeValueOperation <User>("AdminUser", readResult.Index));
// The delete result is successful only if the index has not changed between the read and delete operations
bool deleteResultSuccessful = deleteResult.Successful;
#endregion
}
#region expiration_0
using (IAsyncDocumentSession session = store.OpenAsyncSession())
{
// Set a time exactly one week from now
DateTime expirationTime = DateTime.UtcNow.AddDays(7);
// Create a new compare exchange value
var cmpxchgValue = session.Advanced.ClusterTransaction.CreateCompareExchangeValue("key", "value");
// Edit Metadata
cmpxchgValue.Metadata[Constants.Documents.Metadata.Expires] = expirationTime;
// Send to server
session.SaveChangesAsync();
}
#endregion
using (IAsyncDocumentSession session = store.OpenAsyncSession())
{
#region expiration_1
// Retrieve an existing key
CompareExchangeValue <string> cmpxchgValue = store.Operations.Send(
new GetCompareExchangeValueOperation <string>("key"));
// Set time
DateTime expirationTime = DateTime.UtcNow.AddDays(7);
// Edit Metadata
cmpxchgValue.Metadata[Constants.Documents.Metadata.Expires] = expirationTime;
// Update value. Index must match the index on the server side,
// or the operation will fail.
CompareExchangeResult <string> result = store.Operations.Send(
new PutCompareExchangeValueOperation <string>(
cmpxchgValue.Key,
cmpxchgValue.Value,
cmpxchgValue.Index));
#endregion
}
#region metadata_0
using (IAsyncDocumentSession session = store.OpenAsyncSession(
new SessionOptions {
TransactionMode = TransactionMode.ClusterWide
}))
{
// Create a new compare exchange value
var cmpxchgValue = session.Advanced.ClusterTransaction.CreateCompareExchangeValue("key", "value");
// Add a field to the metadata
// with a value of type string
cmpxchgValue.Metadata["Field name"] = "some value";
// Retrieve metadata as a dictionary
IDictionary <string, object> cmpxchgMetadata = cmpxchgValue.Metadata;
}
#endregion
}
}
public async Task CreateFullAndIncrementalBackupWithCompareExchangeInTheMiddle()
{
var backupPath = NewDataPath(suffix: "BackupFolder");
using (var store = GetDocumentStore())
{
using (var session = store.OpenSession())
{
session.Store(new User
{
Name = "Toli"
}, "users/1");
session.SaveChanges();
}
var config = Backup.CreateBackupConfiguration(backupPath);
var backupTaskId = await Backup.UpdateConfigAndRunBackupAsync(Server, config, store);
CompareExchangeResult <string> compareExchangeResult
= store.Operations.Send(
new PutCompareExchangeValueOperation <string>("users/1", "Mitzi", 0));
WaitForValue(() => compareExchangeResult.Successful, true);
await Backup.RunBackupAsync(Server, backupTaskId, store, isFullBackup : false);
compareExchangeResult
= store.Operations.Send(
new PutCompareExchangeValueOperation <string>("users/1", "Mitzi2", compareExchangeResult.Index));
WaitForValue(() => compareExchangeResult.Successful, true);
await Backup.RunBackupAsync(Server, backupTaskId, store, isFullBackup : false);
var backupDirectory = Directory.GetDirectories(backupPath).First();
var databaseName = GetDatabaseName() + "restore";
var files = Directory.GetFiles(backupDirectory)
.Where(BackupUtils.IsBackupFile)
.OrderBackups()
.ToArray();
RestoreBackupConfiguration config2 = new RestoreBackupConfiguration()
{
BackupLocation = backupDirectory,
DatabaseName = databaseName,
LastFileNameToRestore = files.Last()
};
RestoreBackupOperation restoreOperation = new RestoreBackupOperation(config2);
store.Maintenance.Server.Send(restoreOperation)
.WaitForCompletion();
using (var store2 = GetDocumentStore(new Options()
{
CreateDatabase = false,
ModifyDatabaseName = s => databaseName
}))
{
using (var session = store2.OpenSession())
{
var doc = session.Load <User>("users/1");
Assert.NotNull(doc);
};
CompareExchangeValue <string> readResult =
store2.Operations.Send(new GetCompareExchangeValueOperation <string>("users/1"));
Assert.Equal("Mitzi2", readResult.Value);
};
}
}