/// <summary>
/// Creates and caches a prepared statement. It can be used to optimise queries execution time
/// </summary>
/// <param name="builder">The builder which builds the query</param>
/// <param name=""></param>
/// <returns></returns>
public PreparedStatement GetPreparedStatement(string key, CassandraQueryBuilder builder = null)
{
if (this.CachedStatements.ContainsKey(key))
{
return(this.CachedStatements[key]);
}
if (builder == null)
{
return(null);
}
if (this.currentSession == null)
{
createConnection();
}
try
{
Func <PreparedStatement> waitingFunction = () =>
{
var task = this.statementCreationTasks[key];
task.Wait();
return(this.CachedStatements[key]);
};
if (this.statementCreationTasks.ContainsKey(key))
{
return(waitingFunction());
}
Task creationTask = null;
lock (creatingTask)
{
if (this.statementCreationTasks.ContainsKey(key))
{
return(waitingFunction());
}
creationTask = Task.Run(async() =>
{
PreparedStatement statement = await this.currentSession.PrepareAsync(builder.Build());
this.CachedStatements.AddOrUpdate(key, statement, (k, v) => v);
});
this.statementCreationTasks.TryAdd(key, creationTask);
}
creationTask.Wait();
return(this.CachedStatements[key]);
}
catch
{
return(null);
}
}
public void PrepareQuery(CassandraQueryBuilder builder)
{
this.query = builder.Build();
}
