/// <summary>
/// Returns the detected kind of a serialized sentinel value, or None if it's not a sentinel value.
/// </summary>
/// <param name="value">The serialized value to inspect.</param>
/// <returns>The kind of sentinel serialized in <paramref name="value"/> or None if it's not a sentinel value.</returns>
internal static SentinelKind GetKind(Value value)
{
// If it's not a null value to start with, fetching NullValue returns NullValue.None
// so we'll drop out to the right place.
SentinelKind sentinelKind = (SentinelKind)value.NullValue;
return(sentinelKind > SentinelKind.None && sentinelKind <= s_maxSentinelKind
? sentinelKind : SentinelKind.None);
}
internal static SentinelValue ForArrayValue(SentinelKind sentinelKind, object[] values)
{
GaxPreconditions.CheckNotNull(values, nameof(values));
ArrayValue array = ValueSerializer.Serialize(values).ArrayValue;
// This is just checking that the simple approach we've taken in the previous line
// really did what we expect.
GaxPreconditions.CheckState(array != null, "Input wasn't serialized as an array");
AugmentedValue augmented = new AugmentedValue {
Kind = sentinelKind, Array = array
};
return(new SentinelValue(augmented));
}
/// <summary>
/// Finds all the sentinel values in a field map.
/// Additionally, this validates that no sentinels exist in arrays (even nested).
/// </summary>
/// <param name="fields">The field map to find sentinels within.</param>
/// <returns>The sentinel fields in the field map: both the value and the corresponding field path.</returns>
private static List <SentinelField> FindSentinels(IDictionary <string, Value> fields)
{
List <SentinelField> result = new List <SentinelField>();
FindSentinelsRecursively(fields, FieldPath.Empty);
return(result);
void FindSentinelsRecursively(IDictionary <string, Value> currentFields, FieldPath currentParentPath)
{
foreach (var pair in currentFields)
{
Value value = pair.Value;
string key = pair.Key;
SentinelKind sentinelKind = SentinelValue.GetKind(value);
if (sentinelKind != SentinelKind.None)
{
result.Add(new SentinelField(currentParentPath.Append(key), value));
}
else if (value.MapValue != null)
{
FindSentinelsRecursively(value.MapValue.Fields, currentParentPath.Append(pair.Key));
}
else if (value.ArrayValue != null)
{
ValidateNoSentinelValues(value.ArrayValue.Values);
}
}
}
void ValidateNoSentinelValues(IEnumerable <Value> values)
{
foreach (var value in values)
{
if (SentinelValue.GetKind(value) != SentinelKind.None)
{
// We don't know what parameter name to use here
throw new ArgumentException("Sentinel values must not appear directly or indirectly within array values");
}
else if (value.MapValue != null)
{
ValidateNoSentinelValues(value.MapValue.Fields.Values);
}
else if (value.ArrayValue != null)
{
ValidateNoSentinelValues(value.ArrayValue.Values);
}
}
}
}
internal static SentinelValue ForArrayValue(SerializationContext context, SentinelKind sentinelKind, object[] values)
{
GaxPreconditions.CheckNotNull(values, nameof(values));
ArrayValue array = ValueSerializer.Serialize(context, values).ArrayValue;
// This is just checking that the simple approach we've taken in the previous line
// really did what we expect.
GaxPreconditions.CheckState(array != null, "Input wasn't serialized as an array");
GaxPreconditions.CheckState(!array.Values.Any(FindNestedSentinels), "Sentinel values cannot be nested in array union/remove values.");
AugmentedValue augmented = new AugmentedValue {
Kind = sentinelKind, Array = array
};
return(new SentinelValue(augmented));
}
// There will be other sentinels with more parameters.
private SentinelValue(SentinelKind kind, Func <Value> protoFactory)
{
Kind = kind;
_protoFactory = protoFactory;
}
