/// <summary>
/// Reads persisted state from the backing store and deserializes it into the the target
/// grain state object.
/// </summary>
/// <param name="grainType">A string holding the name of the grain class.</param>
/// <param name="grainReference">Represents the long-lived identity of the grain.</param>
/// <param name="grainState">A reference to an object to hold the persisted state of the grain.</param>
/// <returns>Completion promise for this operation.</returns>
public async Task ReadStateAsync(string grainType, GrainReference grainReference, GrainState grainState)
{
if (DataManager == null) throw new ArgumentException("DataManager property not initialized");
var entityData = await DataManager.Read(grainState.GetType().Name, grainReference.ToKeyString());
if (entityData != null)
{
ConvertFromStorageFormat(grainState, entityData);
}
}
public async Task WriteStateAsync(string grainType, GrainReference grainReference, GrainState grainState)
{
var stateName = grainState.GetType().Name;
var key = grainReference.ToKeyString();
var id = string.Format(CultureInfo.InvariantCulture, "{0}/{1}", stateName, key);
using (IAsyncDocumentSession session = this.documentStore.OpenAsyncSession())
{
await session.StoreAsync(grainState, id);
await session.SaveChangesAsync();
}
}
public async Task ReadStateAsync(string grainType, GrainReference grainReference, GrainState grainState)
{
var stateName = grainState.GetType().Name;
var key = grainReference.ToKeyString();
var id = string.Format(CultureInfo.InvariantCulture, "{0}/{1}", stateName, key);
using (IAsyncDocumentSession session = this.documentStore.OpenAsyncSession())
{
var state = await session.LoadAsync<RavenJObject>(id);
if (state != null)
{
grainState.SetAll(state.ToDictionary(x => x.Key, x => x.Value.Value<object>()));
}
}
}
public async Task ClearStateAsync(string grainType, GrainReference grainReference, GrainState grainState)
{
var stateName = grainState.GetType().Name;
var key = grainReference.ToKeyString();
var id = string.Format(CultureInfo.InvariantCulture, "{0}/{1}", stateName, key);
using (IAsyncDocumentSession session = this.documentStore.OpenAsyncSession())
{
session.Advanced.Defer(new DeleteCommandData
{
Key = id
});
await session.SaveChangesAsync();
}
}
/// <summary>
/// Constructs a grain state instance by deserializing a JSON document.
/// </summary>
/// <param name="grainState">Grain state to be populated for storage.</param>
/// <param name="entityData">JSON storage format representaiton of the grain state.</param>
protected static void ConvertFromStorageFormat(GrainState grainState, string entityData)
{
JavaScriptSerializer deserializer = new JavaScriptSerializer();
object data = deserializer.Deserialize(entityData, grainState.GetType());
var dict = ((GrainState)data).AsDictionary();
grainState.SetAll(dict);
}
/// <summary>
/// Removes grain state from its backing store, if found.
/// </summary>
/// <param name="grainType">A string holding the name of the grain class.</param>
/// <param name="grainReference">Represents the long-lived identity of the grain.</param>
/// <param name="grainState">An object holding the persisted state of the grain.</param>
/// <returns></returns>
public Task ClearStateAsync(string grainType, GrainReference grainReference, GrainState grainState)
{
if (DataManager == null) throw new ArgumentException("DataManager property not initialized");
DataManager.Delete(grainState.GetType().Name, grainReference.ToKeyString());
return TaskDone.Done;
}
/// <summary>
/// Writes the persisted state from a grain state object into its backing store.
/// </summary>
/// <param name="grainType">A string holding the name of the grain class.</param>
/// <param name="grainReference">Represents the long-lived identity of the grain.</param>
/// <param name="grainState">A reference to an object holding the persisted state of the grain.</param>
/// <returns>Completion promise for this operation.</returns>
public Task WriteStateAsync(string grainType, GrainReference grainReference, GrainState grainState)
{
if (DataManager == null) throw new ArgumentException("DataManager property not initialized");
var entityData = ConvertToStorageFormat(grainState);
return DataManager.Write(grainState.GetType().Name, grainReference.ToKeyString(), entityData);
}
private string GetTableName(GrainState grainState)
{
if (Table != null && Table.Length > 0)
return Table;
return grainState.GetType().Name; //use grain name generator if no table provided
}
public async Task ReadStateAsync(string grainType, GrainReference grainReference, GrainState grainState)
{
var con = await GetFreeConnection();
var table = GetTableName(grainState);
string keyAsString = GetKey(grainReference);
string query;
if (CustomTable)
query = string.Format("select * from `{0}` where `guid` = \"{1}\";", table,
MySqlHelper.EscapeString(keyAsString));
else
query = string.Format("select * from `{0}` where `guid` = \"{1}\" AND `type` = \"{2}\";", table,
MySqlHelper.EscapeString(keyAsString), MySqlHelper.EscapeString(grainType));
using (var cmd = new MySqlCommand(query, con))
{
using (var reader = await cmd.ExecuteReaderAsync())
{
if (await reader.ReadAsync())
{
Dictionary<string, object> dict = new Dictionary<string, object>();
for (int i = 0; i < reader.FieldCount; ++i)
dict.Add(reader.GetName(i), reader.GetValue(i));
if (dict.ContainsKey("data"))
{
try
{
var data =
(GrainState)
Newtonsoft.Json.JsonConvert.DeserializeObject(dict["data"].ToString(),
grainState.GetType());
grainState.SetAll(data.AsDictionary());
}
catch
{
grainState.SetAll(null); /* corruption? */
}
}
else
grainState.SetAll(null);
}
}
}
await AddFreeConnection(con);
}
