public XPathNavigator GetContent(string identifier)
{
// get the document containing the identifier
IndexedFile document = GetCachedDocument(identifier);
if (document == null)
{
return(null);
}
// select the comment part of the document
return(document.GetContent(identifier));
}
private IndexedFile GetCachedDocument(string identifier)
{
string file;
if (idToFileMap.TryGetValue(identifier, out file))
{
IndexedFile document;
if (cache.TryGetValue(file, out document))
{
// move the file from its current position to the head of the lru linked list
lruLinkedList.Remove(document.ListNode);
lruLinkedList.AddFirst(document.ListNode);
}
else
{
// not in the cache, so load and index a new source file
document = new IndexedFile(file, valueExpression, keyExpression);
if (cache.Count >= _cacheSize)
{
// the cache is full
// the last node in the linked list has the path of the next file to remove from the cache
if (lruLinkedList.Last != null)
{
cache.Remove(lruLinkedList.Last.Value);
lruLinkedList.RemoveLast();
}
}
// add the new file to the cache and to the head of the lru linked list
cache.Add(file, document);
document.ListNode = lruLinkedList.AddFirst(file);
}
return(document);
}
else
{
return(null);
}
}
private IndexedFile GetCachedDocument(string identifier)
{
string file;
if (idToFileMap.TryGetValue(identifier, out file))
{
IndexedFile document;
if (cache.TryGetValue(file, out document))
{
// move the file from its current position to the head of the lru linked list
lruLinkedList.Remove(document.ListNode);
lruLinkedList.AddFirst(document.ListNode);
}
else
{
// not in the cache, so load and index a new source file
document = new IndexedFile(file, valueExpression, keyExpression);
if (cache.Count >= _cacheSize)
{
// the cache is full
// the last node in the linked list has the path of the next file to remove from the cache
if (lruLinkedList.Last != null)
{
cache.Remove(lruLinkedList.Last.Value);
lruLinkedList.RemoveLast();
}
}
// add the new file to the cache and to the head of the lru linked list
cache.Add(file, document);
document.ListNode = lruLinkedList.AddFirst(file);
}
return (document);
}
else
{
return (null);
}
}