internal override ObjectQueryExecutionPlan GetExecutionPlan(
MergeOption?forMergeOption)
{
MergeOption mergeOption = ObjectQueryState.EnsureMergeOption(forMergeOption, this.UserSpecifiedMergeOption);
ObjectQueryExecutionPlan queryExecutionPlan1 = this._cachedPlan;
if (queryExecutionPlan1 != null)
{
if (queryExecutionPlan1.MergeOption == mergeOption && queryExecutionPlan1.Streaming == this.EffectiveStreamingBehavior)
{
return(queryExecutionPlan1);
}
queryExecutionPlan1 = (ObjectQueryExecutionPlan)null;
}
QueryCacheManager queryCacheManager = (QueryCacheManager)null;
EntitySqlQueryCacheKey key = (EntitySqlQueryCacheKey)null;
if (this.PlanCachingEnabled)
{
key = new EntitySqlQueryCacheKey(this.ObjectContext.DefaultContainerName, this._queryText, this.Parameters == null ? 0 : this.Parameters.Count, this.Parameters == null ? (string)null : this.Parameters.GetCacheKey(), this.Span == null ? (string)null : this.Span.GetCacheKey(), mergeOption, this.EffectiveStreamingBehavior, this.ElementType);
queryCacheManager = this.ObjectContext.MetadataWorkspace.GetQueryCacheManager();
ObjectQueryExecutionPlan queryExecutionPlan2 = (ObjectQueryExecutionPlan)null;
if (queryCacheManager.TryCacheLookup <EntitySqlQueryCacheKey, ObjectQueryExecutionPlan>(key, out queryExecutionPlan2))
{
queryExecutionPlan1 = queryExecutionPlan2;
}
}
if (queryExecutionPlan1 == null)
{
queryExecutionPlan1 = this._objectQueryExecutionPlanFactory.Prepare(this.ObjectContext, DbQueryCommandTree.FromValidExpression(this.ObjectContext.MetadataWorkspace, DataSpace.CSpace, this.Parse(), true), this.ElementType, mergeOption, this.EffectiveStreamingBehavior, this.Span, (IEnumerable <Tuple <ObjectParameter, QueryParameterExpression> >)null, DbExpressionBuilder.AliasGenerator);
if (key != null)
{
QueryCacheEntry inQueryCacheEntry = new QueryCacheEntry((QueryCacheKey)key, (object)queryExecutionPlan1);
QueryCacheEntry outQueryCacheEntry = (QueryCacheEntry)null;
if (queryCacheManager.TryLookupAndAdd(inQueryCacheEntry, out outQueryCacheEntry))
{
queryExecutionPlan1 = (ObjectQueryExecutionPlan)outQueryCacheEntry.GetTarget();
}
}
}
if (this.Parameters != null)
{
this.Parameters.SetReadOnly(true);
}
this._cachedPlan = queryExecutionPlan1;
return(queryExecutionPlan1);
}
internal override ObjectQueryExecutionPlan GetExecutionPlan(MergeOption?forMergeOption)
{
// Determine the required merge option, with the following precedence:
// 1. The merge option specified to Execute(MergeOption) as forMergeOption.
// 2. The merge option set via ObjectQuery.MergeOption.
// 3. The global default merge option.
var mergeOption = EnsureMergeOption(forMergeOption, UserSpecifiedMergeOption);
// If a cached plan is present, then it can be reused if it has the required merge option and streaming behavior
// (since span and parameters cannot change between executions). However, if the cached
// plan does not have the required merge option we proceed as if it were not present.
var plan = _cachedPlan;
if (plan != null)
{
if (plan.MergeOption == mergeOption &&
plan.Streaming == EffectiveStreamingBehavior)
{
return(plan);
}
else
{
plan = null;
}
}
// There is no cached plan (or it was cleared), so the execution plan must be retrieved from
// the global query cache (if plan caching is enabled) or rebuilt for the required merge option.
QueryCacheManager cacheManager = null;
EntitySqlQueryCacheKey cacheKey = null;
if (PlanCachingEnabled)
{
// Create a new cache key that reflects the current state of the Parameters collection
// and the Span object (if any), and uses the specified merge option.
cacheKey = new EntitySqlQueryCacheKey(
ObjectContext.DefaultContainerName,
_queryText,
(null == Parameters ? 0 : Parameters.Count),
(null == Parameters ? null : Parameters.GetCacheKey()),
(null == Span ? null : Span.GetCacheKey()),
mergeOption,
EffectiveStreamingBehavior,
ElementType);
cacheManager = ObjectContext.MetadataWorkspace.GetQueryCacheManager();
ObjectQueryExecutionPlan executionPlan = null;
if (cacheManager.TryCacheLookup(cacheKey, out executionPlan))
{
plan = executionPlan;
}
}
if (plan == null)
{
// Either caching is not enabled or the execution plan was not found in the cache
var queryExpression = Parse();
Debug.Assert(queryExpression != null, "EntitySqlQueryState.Parse returned null expression?");
var tree = DbQueryCommandTree.FromValidExpression(
ObjectContext.MetadataWorkspace, DataSpace.CSpace, queryExpression,
useDatabaseNullSemantics: true);
plan = _objectQueryExecutionPlanFactory.Prepare(
ObjectContext, tree, ElementType, mergeOption, EffectiveStreamingBehavior, Span, null,
DbExpressionBuilder.AliasGenerator);
// If caching is enabled then update the cache now.
// Note: the logic is the same as in ELinqQueryState.
if (cacheKey != null)
{
var newEntry = new QueryCacheEntry(cacheKey, plan);
QueryCacheEntry foundEntry = null;
if (cacheManager.TryLookupAndAdd(newEntry, out foundEntry))
{
// If TryLookupAndAdd returns 'true' then the entry was already present in the cache when the attempt to add was made.
// In this case the existing execution plan should be used.
plan = (ObjectQueryExecutionPlan)foundEntry.GetTarget();
}
}
}
if (Parameters != null)
{
Parameters.SetReadOnly(true);
}
// Update the cached plan with the newly retrieved/prepared plan
_cachedPlan = plan;
// Return the execution plan
return(plan);
}
