/// <summary>Gets a cached plan for the given statement, if available.</summary>
/// <remarks>
/// If a plan is found, it is referenced for the LRU, and disowned by the cache.
/// The client must call Release to return the plan to the cache.
/// If no plan is found, null is returned and the cache is unaffected.
/// </remarks>
public ServerPlan Get(ServerProcess process, string statement, int contextHashCode)
{
ServerPlan plan = null;
CachedPlanHeader header = GetPlanHeader(process, statement, contextHashCode);
CachedPlans bumped = null;
lock (this)
{
if (_plans != null)
{
CachedPlans plans;
if (_plans.TryGetValue(header, out plans))
{
for (int planIndex = plans.Count - 1; planIndex >= 0; planIndex--)
{
plan = plans[planIndex];
plans.RemoveAt(planIndex);
if (process.Catalog.PlanCacheTimeStamp > plan.PlanCacheTimeStamp)
{
DisposeCachedPlan(process, plan);
plan = null;
}
else
{
bumped = _plans.Reference(header, plans);
break;
}
}
}
}
}
if (bumped != null)
{
DisposeCachedPlans(process, bumped);
}
if (plan != null)
{
plan.BindToProcess(process);
}
return(plan);
}
public Schema.CatalogObjectHeaders Resolve(string name)
{
lock (this)
{
if (_cache != null)
{
Schema.CatalogObjectHeaders headers;
if (_cache.TryGetValue(name, out headers))
{
_cache.Reference(name, headers);
}
return(headers);
}
}
return(null);
}