/// <summary>
/// Converts IStoreShardMap to ShardMap.
/// </summary>
/// <param name="manager">Reference to shard map manager.</param>
/// <param name="ssm">Storage representation for ShardMap.</param>
/// <returns>ShardMap object corresponding to storange representation.</returns>
internal static ShardMap CreateShardMapFromStoreShardMap(
ShardMapManager manager,
IStoreShardMap ssm)
{
switch (ssm.MapType)
{
case ShardMapType.List:
// Create ListShardMap<TKey>
return((ShardMap)Activator.CreateInstance(
typeof(ListShardMap <>).MakeGenericType(
ShardKey.TypeFromShardKeyType(ssm.KeyType)),
BindingFlags.NonPublic | BindingFlags.Instance,
null,
new object[] { manager, ssm },
CultureInfo.InvariantCulture));
default:
Debug.Assert(ssm.MapType == ShardMapType.Range);
// Create RangeShardMap<TKey>
return((ShardMap)Activator.CreateInstance(
typeof(RangeShardMap <>).MakeGenericType(
ShardKey.TypeFromShardKeyType(ssm.KeyType)),
BindingFlags.NonPublic | BindingFlags.Instance,
null,
new object[] { manager, ssm },
CultureInfo.InvariantCulture));
}
}
/// <summary>
/// Asynchronously opens a regular <see cref="SqlConnection"/> to the shard
/// to which the specified key value is mapped.
/// </summary>
/// <typeparam name="TKey">Type of the key.</typeparam>
/// <param name="key">Input key value.</param>
/// <param name="connectionString">
/// Connection string with credential information such as SQL Server credentials or Integrated Security settings.
/// The hostname of the server and the database name for the shard are obtained from the lookup operation for key.
/// </param>
/// <param name="options">Options for validation operations to perform on opened connection.</param>
/// <returns>A Task encapsulating an opened SqlConnection.</returns>
/// <remarks>
/// Note that the <see cref="SqlConnection"/> object returned by this call is not protected against transient faults.
/// Callers should follow best practices to protect the connection against transient faults
/// in their application code, e.g., by using the transient fault handling
/// functionality in the Enterprise Library from Microsoft Patterns and Practices team.
/// This call only works if there is a single default mapping.
/// </remarks>
public Task <SqlConnection> OpenConnectionForKeyAsync <TKey>(
TKey key,
string connectionString,
ConnectionOptions options)
{
ExceptionUtils.DisallowNullArgument(connectionString, "connectionString");
Debug.Assert(this.StoreShardMap.KeyType != ShardKeyType.None);
using (ActivityIdScope activityIdScope = new ActivityIdScope(Guid.NewGuid()))
{
IShardMapper <TKey> mapper = this.GetMapper <TKey>();
if (mapper == null)
{
throw new ArgumentException(
StringUtils.FormatInvariant(
Errors._ShardMap_OpenConnectionForKey_KeyTypeNotSupported,
typeof(TKey),
this.StoreShardMap.Name,
ShardKey.TypeFromShardKeyType(this.StoreShardMap.KeyType)),
"key");
}
Debug.Assert(mapper != null);
return(mapper.OpenConnectionForKeyAsync(key, connectionString, options));
}
}
/// <summary>
/// Raise conversion exception.
/// </summary>
/// <typeparam name="TKey">Key type.</typeparam>
/// <param name="ssm">Shard map whose conversion failed.</param>
/// <param name="targetKind">Requested type of shard map.</param>
private static ShardManagementException GetConversionException <TKey>(IStoreShardMap ssm, string targetKind)
{
return(new ShardManagementException(
ShardManagementErrorCategory.ShardMapManager,
ShardManagementErrorCode.ShardMapTypeConversionError,
Errors._ShardMapExtensions_AsTypedShardMap_ConversionFailure,
ssm.Name,
targetKind,
typeof(TKey).Name,
ssm.MapType.ToString(),
ssm.KeyType == ShardKeyType.None ? string.Empty : ShardKey.TypeFromShardKeyType(ssm.KeyType).Name));
}