/// <summary>
/// Initializes Orleans queries from the database. Orleans uses only these queries and the variables therein, nothing more.
/// </summary>
/// <param name="storage">The storage to use.</param>
/// <returns>Orleans queries have been loaded to silo or client memory.</returns>
/// <remarks>This is public only to be usable to the statistics providers. Not intended for public use otherwise.</remarks>
public static async Task <QueryConstantsBag> InitializeOrleansQueriesAsync(this IRelationalStorage storage)
{
var queryConstants = new QueryConstantsBag();
var query = queryConstants.GetConstant(storage.InvariantName, QueryKeys.OrleansQueriesKey);
var orleansQueries = await storage.ReadAsync(query, _ => { }, (selector, _) =>
{
return(Tuple.Create(selector.GetValue <string>("QueryKey"), selector.GetValue <string>("QueryText")));
}).ConfigureAwait(continueOnCapturedContext: false);
//The queries need to be added to be used later with a given key.
foreach (var orleansQuery in orleansQueries)
{
queryConstants.AddOrModifyQueryConstant(storage.InvariantName, orleansQuery.Item1, orleansQuery.Item2);
}
//Check that all the required keys are loaded and throw an exception giving the keys expected but not loaded.
var loadedQueriesKeys = queryConstants.GetAllConstants(storage.InvariantName).Keys;
var missingQueryKeys = QueryKeys.Keys.Except(loadedQueriesKeys);
if (missingQueryKeys.Any())
{
throw new ArgumentException(string.Format("Not all required queries found when loading from the database. Missing are: {0}", string.Join(",", missingQueryKeys)));
}
return(await Task.FromResult(queryConstants));
}
/// <summary>
/// Checks the existence of a database using the given <see paramref="storage"/> storage object.
/// </summary>
/// <param name="databaseName">The name of the database existence of which to check.</param>
/// <returns><em>TRUE</em> if the given database exists. <em>FALSE</em> otherwise.</returns>
private async Task <bool> ExistsDatabaseAsync(string databaseName)
{
var ret = await storage.ReadAsync(string.Format(ExistsDatabaseTemplate, databaseName), command =>
{ }, (selector, resultSetCount) => { return(selector.GetBoolean(0)); }).ConfigureAwait(continueOnCapturedContext: false);
return(ret.First());
}
private async Task <TAggregate> ReadAsync <TResult, TAggregate>(string query,
Func <IDataRecord, TResult> selector,
Func <IDbCommand, DbStoredQueries.Columns> parameterProvider,
Func <IEnumerable <TResult>, TAggregate> aggregator)
{
var ret = await storage.ReadAsync(query, selector, command => parameterProvider(command));
return(aggregator(ret));
}
/// <summary>
/// Uses <see cref="IRelationalStorage"/> with <see cref="DbExtensions.ReflectionParameterProvider{T}(IDbCommand, T, IReadOnlyDictionary{string, string})"/>.
/// </summary>
/// <typeparam name="TResult">The type of the result.</typeparam>
/// <param name="storage">The storage to use.</param>
/// <param name="query">Executes a given statement. Especially intended to use with <em>SELECT</em> statement, but works with other queries too.</param>
/// <param name="parameters">Adds parameters to the query. Parameter names must match those defined in the query.</param>
/// <returns>A list of objects as a result of the <see paramref="query"/>.</returns>
/// <example>This uses reflection to read results and match the parameters.
/// <code>
/// //This struct holds the return value in this example.
/// public struct Information
/// {
/// public string TABLE_CATALOG { get; set; }
/// public string TABLE_NAME { get; set; }
/// }
///
/// //Here reflection (<seealso cref="DbExtensions.ReflectionParameterProvider{T}(IDbCommand, T, IReadOnlyDictionary{string, string})"/>)
/// is used to match parameter names as well as to read back the results (<seealso cref="DbExtensions.ReflectionSelector{TResult}(IDataRecord)"/>).
/// var query = "SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = @tname;";
/// IEnumerable<Information> informationData = await db.ReadAsync<Information>(query, new { tname = 200000 });
/// </code>
/// </example>
public static async Task <IEnumerable <TResult> > ReadAsync <TResult>(this IRelationalStorage storage, string query, object parameters)
{
return(await storage.ReadAsync(query, command =>
{
if (parameters != null)
{
command.ReflectionParameterProvider(parameters);
}
}, (selector, resultSetCount) => selector.ReflectionSelector <TResult>()).ConfigureAwait(continueOnCapturedContext: false));
}
/// <summary>
/// Uses <see cref="IRelationalStorage"/> with <see cref="DbExtensions.ReflectionParameterProvider{T}(IDbCommand, T, IReadOnlyDictionary{string, string})"/>.
/// </summary>
/// <typeparam name="TResult">The type of the result.</typeparam>
/// <param name="storage">The storage to use.</param>
/// <param name="query">Executes a given statement. Especially intended to use with <em>SELECT</em> statement, but works with other queries too.</param>
/// <param name="parameters">Adds parameters to the query. Parameter names must match those defined in the query.</param>
/// <param name="cancellationToken">The cancellation token. Defaults to <see cref="CancellationToken.None"/>.</param>
/// <returns>A list of objects as a result of the <see paramref="query"/>.</returns>
/// <example>This uses reflection to read results and match the parameters.
/// <code>
/// //This struct holds the return value in this example.
/// public struct Information
/// {
/// public string TABLE_CATALOG { get; set; }
/// public string TABLE_NAME { get; set; }
/// }
///
/// //Here reflection (<seealso cref="DbExtensions.ReflectionParameterProvider{T}(IDbCommand, T, IReadOnlyDictionary{string, string})"/>)
/// is used to match parameter names as well as to read back the results (<seealso cref="DbExtensions.ReflectionSelector{TResult}(IDataRecord)"/>).
/// var query = "SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = @tname;";
/// IEnumerable<Information> informationData = await db.ReadAsync<Information>(query, new { tname = 200000 });
/// </code>
/// </example>
public static Task <IEnumerable <TResult> > ReadAsync <TResult>(this IRelationalStorage storage, string query, object parameters, CancellationToken cancellationToken = default(CancellationToken))
{
return(storage.ReadAsync(query, command =>
{
if (parameters != null)
{
command.ReflectionParameterProvider(parameters);
}
}, (selector, resultSetCount, token) => Task.FromResult(selector.ReflectionSelector <TResult>()), cancellationToken));
}
/// <summary>
/// Checks the existence of a database using the given <see paramref="storage"/> storage object.
/// </summary>
/// <param name="storage">The storage to use.</param>
/// <param name="databaseName">The name of the database existence of which to check.</param>
/// <returns><em>TRUE</em> if the given database exists. <em>FALSE</em> otherwise.</returns>
public static async Task <bool> ExistsDatabaseAsync(this IRelationalStorage storage, string query, string databaseName)
{
var ret = await storage.ReadAsync(string.Format(query, databaseName), command =>
{
var p = command.CreateParameter();
p.ParameterName = "databaseName";
p.Value = databaseName;
command.Parameters.Add(p);
}, (selector, resultSetCount) => { return(selector.GetBoolean(0)); }).ConfigureAwait(continueOnCapturedContext: false);
return(ret.First());
}
/// <summary>
/// Creates an instance of a database of type <see cref="RelationalOrleansQueries"/> and Initializes Orleans queries from the database.
/// Orleans uses only these queries and the variables therein, nothing more.
/// </summary>
/// <param name="storage">the underlying storage instance</param>
public static async Task<RelationalOrleansQueries> CreateInstance(IRelationalStorage storage)
{
//this will probably be the same for all relational dbs
const string orleansQueriesSelectTemplate = "SELECT QueryKey, QueryText FROM OrleansQuery;";
var orleansQueries = new OrleansQueries();
var propertiesDictionary = typeof(OrleansQueries).GetFields().ToDictionary(p => p.Name, p => p);
var populatedKeys = await storage.ReadAsync(orleansQueriesSelectTemplate, _ => { }, (selector, _) =>
{
var queryKey = selector.GetValue<string>("QueryKey");
var queryText = selector.GetValue<string>("QueryText");
propertiesDictionary[queryKey].SetValue(orleansQueries, queryText);
return queryKey;
}).ConfigureAwait(continueOnCapturedContext: false);
//Check that all the required keys are loaded and throw an exception giving the keys expected but not loaded.
var missingQueryKeys = populatedKeys.Except(propertiesDictionary.Keys);
if (missingQueryKeys.Any())
{
throw new ArgumentException(string.Format("Not all required queries found when loading from the database. Missing are: {0}", string.Join(",", missingQueryKeys)));
}
return new RelationalOrleansQueries(storage, orleansQueries);
}
/// <summary>
/// A simplified version of <see cref="IRelationalStorage.ReadAsync{TResult}"/>
/// </summary>
/// <param name="storage"></param>
/// <param name="query"></param>
/// <param name="selector"></param>
/// <param name="parameterProvider"></param>
/// <typeparam name="TResult"></typeparam>
/// <returns></returns>
public static Task <IEnumerable <TResult> > ReadAsync <TResult>(this IRelationalStorage storage, string query, Func <IDataRecord, TResult> selector, Action <IDbCommand> parameterProvider)
{
return(storage.ReadAsync(query, parameterProvider, (record, i, cancellationToken) => Task.FromResult(selector(record))));
}