/// <summary>
/// Check the cache.
/// </summary>
/// <param name="key">Key to look up.</param>
/// <param name="result">The value result - either from cache or freshly determined.</param>
/// <param name="valueFactory">A callback that will provide the values.</param>
/// <returns></returns>
protected bool TryGetOrAdd(TKey key, out TValue result, Func <TKey, TValue> valueFactory)
{
bool fromCache = false;
// Wrap value-factory to handle cache invalidator
Func <TKey, TValue> valueFactoryImpl = (k) =>
{
TValue innerResult;
using (CacheContext cacheContext = new CacheContext())
{
innerResult = valueFactory(key);
// Add the cache context entries to the appropriate CacheInvalidator
_cacheInvalidator.AddInvalidations(cacheContext, key);
}
return(innerResult);
};
// Check cache
fromCache = Cache.TryGetOrAdd(key, out result, valueFactoryImpl);
if (fromCache && CacheContext.IsSet())
{
// Add the already stored changes that should invalidate this cache
// entry to any outer or containing cache contexts.
using (CacheContext cacheContext = CacheContext.GetContext())
{
cacheContext.AddInvalidationsFor(_cacheInvalidator, key);
}
}
return(fromCache);
}
/// <summary>
/// Load the roles recursively for a user or role.
/// </summary>
/// <param name="subjectId">
/// The user to load the roles for. This cannot be negative.
/// </param>
/// <returns>
/// The roles the user is recursively a member of.
/// </returns>
/// <exception cref="ArgumentException">
/// <paramref name="subjectId"/> cannot be negative.
/// </exception>
public ISet <long> GetUserRoles(long subjectId)
{
ISet <long> roles;
if (!Cache.TryGetValue(subjectId, out roles))
{
using (CacheContext cacheContext = new CacheContext())
{
roles = RoleRepository.GetUserRoles(subjectId);
Cache[subjectId] = roles;
_cacheInvalidator.AddInvalidations(cacheContext, subjectId);
}
}
else
{
// Add the already stored changes that should invalidate this cache
// entry to any outer or containing cache contexts.
using (CacheContext cacheContext = CacheContext.GetContext( ))
{
cacheContext.AddInvalidationsFor(_cacheInvalidator, subjectId);
}
}
return(roles);
}
public void Test_AddInvalidationsFor_NullCacheInvalidator()
{
using (CacheContext cacheContext = new CacheContext())
{
Assert.That(() => cacheContext.AddInvalidationsFor <int, int>(null, 1),
Throws.TypeOf <ArgumentNullException>().And.Property("ParamName").EqualTo("cacheInvalidator"));
}
}
/// <summary>
/// Execute a request for bulk data from the SQL database.
/// </summary>
/// <param name="request">The requested data</param>
/// <returns></returns>
public BulkRequestResult GetBulkResult(EntityRequest request)
{
if (request == null)
{
throw new ArgumentNullException("request");
}
// Bypass cache
if (request.IgnoreResultCache)
{
return(CreateResult(request));
}
BulkRequestResult result;
CachingBulkRequestRunnerValue cacheValue;
CachingBulkRequestRunnerKey key = CachingBulkRequestRunnerKey.Create(request);
// Check cache
bool inCache = Cache.TryGetValue(key, out cacheValue);
// Should parent cache contexts be notified of invalidations
// .. no for now, for compatibility with previous system. Consider changing
bool notifyParentCacheContext = false;
if (!inCache)
{
using (var cacheContext = new CacheContext(notifyParentCacheContext ? ContextType.New : ContextType.Detached)) // Detached for now..
{
result = CreateResult(request);
cacheValue = new CachingBulkRequestRunnerValue(result);
Cache.Add(key, cacheValue);
// Add the cache context entries to the appropriate CacheInvalidator
cacheContext.Entities.Add(result.AllEntities.Keys);
cacheContext.EntityInvalidatingRelationshipTypes.Add(GetRelationshipTypesUsed(result));
_cacheInvalidator.AddInvalidations(cacheContext, key);
}
}
else
{
if (notifyParentCacheContext && CacheContext.IsSet( ))
{
using (CacheContext cacheContext = new CacheContext(ContextType.Attached))
{
// Add the already stored changes that should invalidate this cache
// entry to any outer or containing cache contexts.
cacheContext.AddInvalidationsFor(_cacheInvalidator, key);
}
}
}
result = cacheValue.BulkRequestResult;
request.ResultFromCache = inCache; // TODO: Find a better channel to return this info. (It can't be in the response, because that's cached)
return(result);
}
/// <summary>
/// Convert a <see cref="Report" /> to a <see cref="StructuredQuery" />.
/// </summary>
/// <param name="report">The <see cref="Report" /> to convert. This cannot be null.</param>
/// <param name="settings"></param>
/// <returns>
/// The converted report.
/// </returns>
/// <exception cref="System.ArgumentNullException">report</exception>
public StructuredQuery Convert(Report report, ReportToQueryConverterSettings settings)
{
if (report == null)
{
throw new ArgumentNullException("report");
}
if (settings == null)
{
settings = ReportToQueryConverterSettings.Default;
}
StructuredQuery result;
CachingReportToQueryConverterValue cacheValue;
CachingReportToQueryConverterKey key = new CachingReportToQueryConverterKey(report, settings);
using (MessageContext msg = new MessageContext("Reports"))
{
// Check cache
bool doConvert = !TryGetValue(key, msg, out cacheValue);
// Check for force recalculation
if (settings.RefreshCachedStructuredQuery)
{
msg.Append(() => "CachingReportToQueryConverter refreshed forced");
doConvert = true;
}
if (doConvert)
{
lock (_syncRoot)
{
using (CacheContext cacheContext = new CacheContext( ))
{
result = Converter.Convert(report, settings);
cacheValue = new CachingReportToQueryConverterValue(result);
Cache.Add(key, cacheValue);
// Add the cache context entries to the appropriate CacheInvalidator
_cacheInvalidator.AddInvalidations(cacheContext, key);
}
}
}
else if (CacheContext.IsSet( ))
{
// Add the already stored changes that should invalidate this cache
// entry to any outer or containing cache contexts.
using (CacheContext cacheContext = CacheContext.GetContext( ))
{
cacheContext.AddInvalidationsFor(_cacheInvalidator, key);
}
}
}
result = cacheValue.StructuredQuery;
return(result);
}
/// <summary>
/// Build an <see cref="EntityMemberRequest"/> used to look for entities
/// to perform additional security checks on.
/// </summary>
/// <param name="entityType">
/// The type of entity whose security is being checked. This cannot be null.
/// </param>
/// <param name="permissions">The type of permissions required.</param>
/// <returns>
/// The <see cref="EntityMemberRequest"/>.
/// </returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="entityType"/> cannot be null.
/// </exception>
public EntityMemberRequest BuildEntityMemberRequest(EntityType entityType, IList <EntityRef> permissions)
{
if (entityType == null)
{
throw new ArgumentNullException("entityType");
}
bool isModify = false;
if (permissions != null)
{
foreach (EntityRef perm in permissions)
{
if (perm.Id == Permissions.Modify.Id || perm.Id == Permissions.Delete.Id)
{
isModify = true;
break;
}
}
}
// negative keys for 'modify', +ve keys for read
// because #27911 popped up just hours before the branch of a feature that got promised to someone
long cacheKey = isModify ? -entityType.Id : entityType.Id;
EntityMemberRequest result;
if (!Cache.TryGetValue(cacheKey, out result))
{
using (CacheContext cacheContext = new CacheContext())
{
result = Factory.BuildEntityMemberRequest(entityType, permissions);
Cache.Add(cacheKey, result);
_cacheInvalidator.AddInvalidations(cacheContext, cacheKey);
}
}
else if (CacheContext.IsSet( ))
{
// Add the already stored changes that should invalidate this cache
// entry to any outer or containing cache contexts.
using (CacheContext cacheContext = CacheContext.GetContext( ))
{
cacheContext.AddInvalidationsFor(_cacheInvalidator, cacheKey);
}
}
return(result);
}
/// <summary>
/// Gets a value that represents a hash of the IDs of a set of security rules.
/// That is, if two users have equatable UserRuleSets then the same security rules apply to both.
/// </summary>
/// <param name="userId">
/// The ID of the user <see cref="UserAccount"/>.
/// This cannot be negative.
/// </param>
/// <param name="permission">
/// The permission to get the query for. This cannot be null and should be one of <see cref="Permissions.Read"/>,
/// <see cref="Permissions.Modify"/> or <see cref="Permissions.Delete"/>.
/// </param>
public UserRuleSet GetUserRuleSet(long userId, EntityRef permission)
{
// Validate
if (userId <= 0)
{
throw new ArgumentNullException("userId");
}
if (permission == null)
{
throw new ArgumentNullException("permission");
}
if (permission.Id <= 0)
{
throw new ArgumentException("permission");
}
// Create cache key
CachingUserRuleSetProviderKey key = new CachingUserRuleSetProviderKey(userId, permission.Id);
UserRuleSet result;
Func <CachingUserRuleSetProviderKey, UserRuleSet> valueFactory = (k) =>
{
UserRuleSet innerResult;
using (CacheContext cacheContext = new CacheContext())
{
innerResult = InnerProvider.GetUserRuleSet(k.SubjectId, k.PermissionId);
// Add the cache context entries to the appropriate CacheInvalidator
_cacheInvalidator.AddInvalidations(cacheContext, key);
}
return(innerResult);
};
// Check cache
if (Cache.TryGetOrAdd(key, out result, valueFactory) &&
CacheContext.IsSet())
{
// Add the already stored changes that should invalidate this cache
// entry to any outer or containing cache contexts.
using (CacheContext cacheContext = CacheContext.GetContext( ))
{
cacheContext.AddInvalidationsFor(_cacheInvalidator, key);
}
}
return(result);
}
/// <summary>
/// Get the queries for a given user and permission or operation.
/// </summary>
/// <param name="subjectId">
/// The ID of the <see cref="Subject"/>, that is a <see cref="UserAccount"/> or <see cref="Role"/> instance.
/// This cannot be negative.
/// </param>
/// <param name="permission">
/// The permission to get the query for. This should be one of <see cref="Permissions.Read"/>,
/// <see cref="Permissions.Modify"/> or <see cref="Permissions.Delete"/>. Or null to match all permissions.
/// </param>
/// <param name="securableEntityTypes">
/// The IDs of <see cref="SecurableEntity"/> types being accessed. Or null to match all entity types.
/// </param>
/// <returns>
/// The queries to run.
/// </returns>
/// <exception cref="ArgumentException">
/// <paramref name="subjectId"/> does not exist. Also, <paramref name="permission"/> should
/// be one of <see cref="Permissions.Read"/>, <see cref="Permissions.Modify"/> or <see cref="Permissions.Delete"/>
/// </exception>
/// <exception cref="ArgumentNullException">
/// Neither <paramref name="permission"/> nor <paramref name="securableEntityTypes"/> can be null.
/// </exception>
public IEnumerable <AccessRuleQuery> GetQueries(long subjectId, [CanBeNull] Model.EntityRef permission, [CanBeNull] IList <long> securableEntityTypes)
{
SubjectPermissionTypesTuple tuple;
IEnumerable <AccessRuleQuery> result;
result = null;
tuple = new SubjectPermissionTypesTuple(subjectId, permission, securableEntityTypes);
if (!Cache.TryGetValue(tuple, out result))
{
using (CacheContext cacheContext = new CacheContext( ))
{
result = Repository.GetQueries(subjectId, permission, securableEntityTypes).ToList( );
try
{
Cache.Add(tuple, result);
// Add the cache context entries to the appropriate CacheInvalidator
_cacheInvalidator.AddInvalidations(cacheContext, tuple);
}
catch (ArgumentException)
{
Trace.WriteLine("CachingQueryRepository: Entity already in cache");
throw;
}
}
}
else if (CacheContext.IsSet( ))
{
using (CacheContext cacheContext = CacheContext.GetContext( ))
{
// Add the already stored changes that should invalidate this cache
// entry to any outer or containing cache contexts.
cacheContext.AddInvalidationsFor(_cacheInvalidator, tuple);
}
}
return(result);
}
/// <summary>
/// Convert a <see cref="Report" /> to a <see cref="StructuredQuery" />.
/// </summary>
/// <param name="typeIds">The type ids.</param>
/// <returns>
/// The converted report.
/// </returns>
/// <exception cref="System.ArgumentNullException">report</exception>
public IEnumerable <Workflow> Fetch(ISet <long> typeIds)
{
if (typeIds == null)
{
throw new ArgumentNullException("typeIds");
}
CachingWorkflowActionsFactoryValue cacheValue;
var key = new CachingWorkflowActionsFactoryKey(typeIds);
// Check cache
bool found = Cache.TryGetOrAdd(key, out cacheValue, (innerKey) =>
{
using (CacheContext cacheContext = new CacheContext( ))
{
var result = new CachingWorkflowActionsFactoryValue(_fetcher.Fetch(innerKey.TypeIds));
// Add the cache context entries to the appropriate CacheInvalidator
_cacheInvalidator.AddInvalidations(cacheContext, key);
return(result);
}
}
);
if (found && CacheContext.IsSet( ))
{
// Add the already stored changes that should invalidate this cache
// entry to any outer or containing cache contexts.
using (CacheContext cacheContext = CacheContext.GetContext( ))
{
cacheContext.AddInvalidationsFor(_cacheInvalidator, key);
}
}
return(cacheValue.Workflows);
}
/// <summary>
/// Re-used cache checking logic that can be used for caching eithe instances lookups or type lookups.
/// </summary>
/// <param name="entities">The entities/types to check. This cannot be null or contain null.</param>
/// <param name="permissions">The permissions or operations to check. This cannot be null or contain null.</param>
/// <param name="user">The user requesting access. This cannot be null.</param>
/// <param name="entityIdCallback">Callback used to determine how to get the ID of TEntity.</param>
/// <param name="innerCheckAccessCallback">Callback used to perform the uncached check.</param>
/// <returns>A mapping of each entity ID to whether the user has access (true) or not (false).</returns>
private IDictionary <long, bool> CachedCheckImpl <TEntity>(IList <TEntity> entities, IList <EntityRef> permissions, EntityRef user,
Func <TEntity, long> entityIdCallback,
Func <IList <TEntity>, IList <EntityRef>, EntityRef, IDictionary <long, bool> > innerCheckAccessCallback)
{
TKey cacheKey;
CachingEntityAccessControlCheckerResult result;
IList <TEntity> toCheckEntities;
long[] permissionIdArray;
IDictionary <long, bool> innerResult;
// If SecurityBypassContext is active, avoid the cache. Otherwise,
// the cache will remember the user had access to entities that
// they may not have.
if (EntityAccessControlChecker.SkipCheck(user))
{
innerResult = innerCheckAccessCallback(entities, permissions, user);
return(innerResult);
}
result = new CachingEntityAccessControlCheckerResult();
toCheckEntities = null;
permissionIdArray = permissions.Select(x => x.Id).ToArray();
// Determine uncached entities
using (CacheContext cacheContext = CacheContext.IsSet( ) ? CacheContext.GetContext( ) : null)
{
foreach (TEntity entity in entities)
{
long entityId = entityIdCallback(entity);
cacheKey = CreateKey(user.Id, entityId, permissionIdArray);
bool cacheEntry;
if (Cache.TryGetValue(cacheKey, out cacheEntry))
{
result.CacheResult[entityId] = cacheEntry;
// Add the already stored changes that should invalidate this cache
// entry to any outer or containing cache contexts.
if (cacheContext != null)
{
cacheContext.AddInvalidationsFor(_cacheInvalidator, cacheKey);
}
}
else
{
if (toCheckEntities == null)
{
toCheckEntities = new List <TEntity>();
}
toCheckEntities.Add(entity);
}
}
}
LogMessage(result);
if (toCheckEntities != null)
{
using (CacheContext cacheContext = new CacheContext( ))
{
innerResult = innerCheckAccessCallback(toCheckEntities, permissions, user);
foreach (KeyValuePair <long, bool> entry in innerResult)
{
long entityId = entry.Key;
bool accessGranted = entry.Value;
result.Add(entityId, accessGranted);
// Cache the results
cacheKey = CreateKey(user.Id, entry.Key, permissionIdArray);
Cache [cacheKey] = accessGranted;
// Add the cache context entries to the appropriate CacheInvalidator
_cacheInvalidator.AddInvalidations(cacheContext, cacheKey);
}
}
}
// Add the results from the originally cached entities
foreach (KeyValuePair <long, bool> entry in result.CacheResult)
{
result[entry.Key] = entry.Value;
}
return(result);
}
/// <summary>
/// Build the SQL, or collect it from cache.
/// </summary>
/// <param name="query"></param>
/// <param name="settings"></param>
/// <returns></returns>
public QueryResult ExecuteQuery(StructuredQuery query, QuerySettings settings)
{
// Validate
if (query == null)
{
throw new ArgumentNullException("query");
}
if (QueryRunner == null)
{
throw new InvalidOperationException("QueryRunner not set.");
}
if (settings == null)
{
settings = new QuerySettings( );
}
// Determine if we should cache .. and the cache key
QueryBuild builtQuery;
CachingQueryRunnerKey key;
CacheContext queryBuilderCacheContext;
using (queryBuilderCacheContext = new CacheContext())
{
key = CreateCacheKeyAndQuery(query, settings, out builtQuery);
}
// A null key means that the ersult should not participate in caching
if (key == null)
{
return(RunQueryImpl(query, settings, builtQuery));
}
CachingQueryRunnerValue cacheValue;
using (MessageContext msg = new MessageContext("Reports"))
{
// Check for force recalculation
if (settings.RefreshCachedResult)
{
msg.Append(() => "CachingQueryRunner refreshed forced");
Cache.Remove(key);
}
// Run query
bool fromCache = TryGetOrAdd(key, msg, out cacheValue, callbackKey =>
{
using (CacheContext cacheContext = new CacheContext( ))
{
QueryResult queryResult = RunQueryImpl(query, settings, builtQuery);
cacheValue = new CachingQueryRunnerValue(query, queryResult);
// Add the cache context entries to the appropriate CacheInvalidator
_cacheInvalidator.AddInvalidations(cacheContext, callbackKey);
_cacheInvalidator.AddInvalidations(queryBuilderCacheContext, callbackKey);
}
return(cacheValue);
});
if (fromCache && CacheContext.IsSet())
{
using (CacheContext cacheContext = CacheContext.GetContext( ))
{
// Add the already stored changes that should invalidate this cache
// entry to any outer or containing cache contexts.
cacheContext.AddInvalidationsFor(_cacheInvalidator, key);
}
}
}
if (cacheValue == null)
{
throw new Exception("Assert false");
}
// Mutate returned result to be suitable for current query
QueryResult result;
if (cacheValue.OriginalQuery == query)
{
result = cacheValue.QueryResult;
}
else
{
result = MutateResultToMatchCurrentQuery(cacheValue, query);
}
return(result);
}
public void Test_AddInvalidationsFor(long[] entities, long[] relationshipTypes, long[] fieldTypes, long[] entityInvalidatingRelationshipTypes)
{
CacheInvalidator <long, long> cacheInvalidator;
const int testKey = 1;
IList <long> entityRefs;
IList <long> relationshipTypeRefs;
IList <long> fieldTypeRefs;
IList <long> entityInvalidatingRelationshipTypeRefs;
entityRefs = entities.ToList();
relationshipTypeRefs = relationshipTypes.ToList();
fieldTypeRefs = fieldTypes.ToList();
entityInvalidatingRelationshipTypeRefs = entityInvalidatingRelationshipTypes.ToList();
cacheInvalidator = new CacheInvalidator <long, long>(new DictionaryCache <long, long>(), "test");
using (CacheContext originalCacheContext = new CacheContext())
{
originalCacheContext.Entities.Add(entityRefs);
originalCacheContext.RelationshipTypes.Add(relationshipTypeRefs);
originalCacheContext.FieldTypes.Add(fieldTypeRefs);
originalCacheContext.EntityInvalidatingRelationshipTypes.Add(entityInvalidatingRelationshipTypeRefs);
cacheInvalidator.AddInvalidations(originalCacheContext, testKey);
}
using (CacheContext outerCacheContext = new CacheContext())
using (CacheContext innerCacheContext = new CacheContext())
{
Assert.That(innerCacheContext.Entities, Is.Empty, "Entities not initially empty");
Assert.That(innerCacheContext.RelationshipTypes, Is.Empty, "RelationshipTypes not initially empty");
Assert.That(innerCacheContext.FieldTypes, Is.Empty, "FieldTypes not initially empty");
Assert.That(innerCacheContext.EntityInvalidatingRelationshipTypes, Is.Empty, "EntityInvalidatingRelationshipTypes not initially empty");
innerCacheContext.AddInvalidationsFor(cacheInvalidator, testKey);
Assert.That(innerCacheContext.Entities,
Is.EquivalentTo(entityRefs).Using(EntityRefComparer.Instance),
"Unexpected Entities");
Assert.That(innerCacheContext.RelationshipTypes,
Is.EquivalentTo(relationshipTypeRefs).Using(EntityRefComparer.Instance),
"Unexpected RelationshipTypes");
Assert.That(innerCacheContext.FieldTypes,
Is.EquivalentTo(fieldTypeRefs).Using(EntityRefComparer.Instance),
"Unexpected FieldTypes");
Assert.That(innerCacheContext.EntityInvalidatingRelationshipTypes,
Is.EquivalentTo(entityInvalidatingRelationshipTypeRefs).Using(EntityRefComparer.Instance),
"Unexpected EntityInvalidatingRelationshipTypes");
Assert.That(outerCacheContext.Entities,
Is.EquivalentTo(entityRefs).Using(EntityRefComparer.Instance),
"Unexpected Entities in outer cache context");
Assert.That(outerCacheContext.RelationshipTypes,
Is.EquivalentTo(relationshipTypeRefs).Using(EntityRefComparer.Instance),
"Unexpected RelationshipTypes in outer cache context");
Assert.That(outerCacheContext.FieldTypes,
Is.EquivalentTo(fieldTypeRefs).Using(EntityRefComparer.Instance),
"Unexpected FieldTypes in outer cache context");
Assert.That(outerCacheContext.EntityInvalidatingRelationshipTypes,
Is.EquivalentTo(entityInvalidatingRelationshipTypeRefs).Using(EntityRefComparer.Instance),
"Unexpected EntityInvalidatingRelationshipTypes in outer cache context");
}
}
/// <summary>
/// Build the SQL, or collect it from cache.
/// </summary>
/// <param name="query"></param>
/// <param name="settings"></param>
/// <returns></returns>
public QueryBuild BuildSql(StructuredQuery query, QuerySqlBuilderSettings settings)
{
// Validate
if (query == null)
{
throw new ArgumentNullException("query");
}
if (QuerySqlBuilder == null)
{
throw new InvalidOperationException("QuerySqlBuilder not set.");
}
if (settings == null)
{
settings = new QuerySqlBuilderSettings( );
}
// Check if query can even participate in cache
if (!CachingQuerySqlBuilderKey.DoesRequestAllowForCaching(query, settings))
{
return(BuildSqlImpl(query, settings));
}
// Get a user-set key
// (Users may share the same report SQL if they have the same set of read-rules)
UserRuleSet userRuleSet = null;
if (settings.RunAsUser != 0)
{
userRuleSet = UserRuleSetProvider.GetUserRuleSet(settings.RunAsUser, Permissions.Read);
if (userRuleSet == null)
{
throw new InvalidOperationException("Expected userRuleSet"); // Assert false
}
}
// Create cache key
CachingQuerySqlBuilderKey key = new CachingQuerySqlBuilderKey(query, settings, userRuleSet);
CachingQuerySqlBuilderValue cacheValue;
using (MessageContext msg = new MessageContext("Reports"))
{
// Check for force recalculation
if (settings.RefreshCachedSql)
{
msg.Append(() => "CachingQuerySqlBuilder refreshed forced");
_cacheInvalidator.DebugInvalidations.Add(key);
Cache.Remove(key);
}
// In some circumstances, a result will be uncacheable, so we just return 'null' in the delegate instead.
// However, on the first access, we will still be doing the calculation, so store it here.
CachingQuerySqlBuilderValue calculatedOnThisAccess = null;
// Check cache
bool fromCache = TryGetOrAdd(key, msg, out cacheValue, callbackKey =>
{
// This callback is called if we have a cache miss
using (CacheContext cacheContext = new CacheContext( ))
{
QueryBuild queryResult = BuildSqlImpl(query, settings);
cacheValue = new CachingQuerySqlBuilderValue(query, queryResult);
calculatedOnThisAccess = cacheValue;
if (queryResult.SqlIsUncacheable)
{
return(null);
}
else
{
// Add the cache context entries to the appropriate CacheInvalidator
_cacheInvalidator.AddInvalidations(cacheContext, callbackKey);
return(cacheValue);
}
}
});
// cacheValue will be null if the result was uncacheable
if (cacheValue == null)
{
if (calculatedOnThisAccess != null)
{
// In this path, the result was uncacheable, so the cache returned a 'null',
// but it was the initial calculation run anyway, so we can get the value from callbackValue.
cacheValue = calculatedOnThisAccess;
}
else
{
// In this path, the result was uncacheable, but someone had asked previously, and stored
// the null, so we need to actually build the SQL again for this scenario.
// Note: don't need to do anything with cache context, because this cache is not participating.
// And if there's a parent context set, then the call to BuildSqlImpl will just talk directly to that context.
QueryBuild queryResult = BuildSqlImpl(query, settings);
cacheValue = new CachingQuerySqlBuilderValue(query, queryResult);
}
}
else if (fromCache && CacheContext.IsSet( ))
{
// Add the already stored changes that should invalidate this cache
// entry to any outer or containing cache contexts.
using (CacheContext cacheContext = CacheContext.GetContext( ))
{
cacheContext.AddInvalidationsFor(_cacheInvalidator, key);
}
}
}
if (cacheValue == null)
{
throw new Exception("Assert false");
}
// Mutate returned result to be suitable for current query
QueryBuild result;
if (cacheValue.OriginalQuery == query)
{
result = cacheValue.QueryResult;
}
else
{
result = MutateResultToMatchCurrentQuery(cacheValue, query);
}
return(result);
}
/// <summary>
/// Helper method to fetch multiple entries from cache, then only call the factory for missing entries.
/// </summary>
/// <remarks>
/// Implementation notes:
/// 1. The result is guaranteed to always be non-null
/// 2. And contain the same entries as the keys in the same order.
/// 3. All misses get evaluated in a single round
/// 4. Caution: because all misses are evaluated together, they get bound together with the same invalidation.
/// </remarks>
/// <param name="keys"></param>
/// <param name="valuesFactory"></param>
/// <returns></returns>
protected IReadOnlyCollection <KeyValuePair <TKey, TValue> > GetOrAddMultiple(IEnumerable <TKey> keys, Func <IEnumerable <TKey>, IEnumerable <TValue> > valuesFactory)
{
if (keys == null)
{
throw new ArgumentNullException("keys");
}
if (valuesFactory == null)
{
throw new ArgumentNullException("valuesFactory");
}
List <KeyValuePair <TKey, TValue> > result = new List <KeyValuePair <TKey, TValue> >();
KeyValuePair <TKey, TValue> resultEntry;
// List of missing entries, including the index position where the result needs to be written
List <Tuple <TKey, int> > cacheMisses = null;
using (CacheContext cacheContext = CacheContext.IsSet() ? CacheContext.GetContext() : null)
{
// First pass through list
int pos = 0;
foreach (TKey key in keys)
{
TValue value;
if (Cache.TryGetValue(key, out value))
{
resultEntry = new KeyValuePair <TKey, TValue>(key, value);
// Check cache
if (cacheContext != null)
{
cacheContext.AddInvalidationsFor(_cacheInvalidator, key);
}
}
else
{
if (cacheMisses == null)
{
cacheMisses = new List <Tuple <TKey, int> >();
}
cacheMisses.Add(new Tuple <TKey, int>(key, pos));
// An entry still gets added to the result to maintain ordering - it will be overridden later
// (can't use null .. kvp is a struct)
resultEntry = new KeyValuePair <TKey, TValue>(key, default(TValue));
}
result.Add(resultEntry);
pos++;
}
}
// Fill in misses
if (cacheMisses != null)
{
using (CacheContext cacheContext = new CacheContext())
{
IEnumerable <TKey> missingKeys = cacheMisses.Select(k => k.Item1);
IEnumerable <TValue> missingResults = valuesFactory(missingKeys);
Enumerable.Zip(cacheMisses, missingResults, (keyPos, value) =>
{
TKey key = keyPos.Item1;
int resultIndex = keyPos.Item2;
resultEntry = new KeyValuePair <TKey, TValue>(key, value);
// Include in current result
result[resultIndex] = resultEntry;
// Add to cache
Cache.Add(key, value);
// Add the cache context entries to the appropriate CacheInvalidator
_cacheInvalidator.AddInvalidations(cacheContext, key);
return((object)null);
}).Last(); // call Last to force evaluate zip
}
}
return(result);
}
