public IEnumerable<ModelValidator> GetValidators(ModelMetadata metadata)
{
// If metadata is for a property then containerType != null && propertyName != null
// If metadata is for a type then containerType == null && propertyName == null, so we have to use modelType for the cache key.
Type typeForCache = metadata.ContainerType ?? metadata.ModelType;
Tuple<Type, string> cacheKey = Tuple.Create(typeForCache, metadata.PropertyName);
ModelValidator[] validators;
// Try to find validator into fast cache first
if (!this.fastCache.TryGetValue(cacheKey, out validators))
{
if (!this.validatorCache.TryGetValue(cacheKey, out validators))
{
// Compute validators
// There are no side-effects if the same validators are created more than once
validators = metadata.GetValidators(this.validatorProviders.Value).ToArray();
this.validatorCache.TryAdd(cacheKey, validators);
}
// Fastcache is out of sync. Resync it.
// Resync could miss some addition to the validatorCache but it will be OK after a few iterations.
// Works well if there is a lot of read operations
Interlocked.Exchange(ref this.fastCache, new Dictionary<Tuple<Type, string>, ModelValidator[]>(this.validatorCache));
}
return validators;
}
// Validates a single node (not including children)
// Returns true if validation passes successfully
private static bool ShallowValidate(ModelMetadata metadata, ValidationContext validationContext, object container)
{
Contract.Requires(validationContext != null);
bool isValid = true;
string key = null;
IModelValidatorCache validatorCache = validationContext.ValidatorCache;
ModelValidator[] validators;
if (validatorCache == null)
{
// slow path: there is no validator cache on the configuration
validators = metadata.GetValidators(validationContext.ValidatorProviders).AsArray();
}
else
{
validators = validatorCache.GetValidators(metadata).AsArray();
}
for (int index = 0; index < validators.Length; index++)
{
ModelValidator validator = validators[index];
foreach (ModelValidationResult error in validator.Validate(metadata, container))
{
if (key == null)
{
key = validationContext.RootPrefix;
foreach (IKeyBuilder keyBuilder in validationContext.KeyBuilders.Reverse())
{
key = keyBuilder.AppendTo(key);
}
}
validationContext.ModelState.AddModelError(key, error.Message);
isValid = false;
}
}
return isValid;
}