private string GetDocumentation(string key, bool allowReload)
{
int hashcode = GetHashCode(key);
var index = this.index; // read volatile field
// index is sorted, so we can use binary search
int m = Array.BinarySearch(index, new IndexEntry(hashcode, 0));
if (m < 0)
{
return(null);
}
// correct hash code found.
// possibly there are multiple items with the same hash, so go to the first.
while (--m >= 0 && index[m].HashCode == hashcode)
{
;
}
// m is now 1 before the first item with the correct hash
XmlDocumentationCache cache = this.cache;
lock (cache)
{
string val;
if (!cache.TryGet(key, out val))
{
try
{
// go through all items that have the correct hash
while (++m < index.Length && index[m].HashCode == hashcode)
{
val = LoadDocumentation(key, index[m].PositionInFile);
if (val != null)
{
break;
}
}
// cache the result (even if it is null)
cache.Add(key, val);
}
catch (IOException)
{
// may happen if the documentation file was deleted/is inaccessible/changed (EndOfStreamException)
return(allowReload ? ReloadAndGetDocumentation(key) : null);
}
catch (XmlException)
{
// may happen if the documentation file was changed so that the file position no longer starts on a valid XML element
return(allowReload ? ReloadAndGetDocumentation(key) : null);
}
}
return(val);
}
}
/// <summary>
/// Get the documentation for the member with the specified documentation key.
/// </summary>
public string GetDocumentation(string key)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
int hashcode = GetHashCode(key);
// index is sorted, so we can use binary search
int m = Array.BinarySearch(index, new IndexEntry(hashcode, 0));
if (m < 0)
{
return(null);
}
// correct hash code found.
// possibly there are multiple items with the same hash, so go to the first.
while (--m >= 0 && index[m].HashCode == hashcode)
{
;
}
// m is now 1 before the first item with the correct hash
XmlDocumentationCache cache = this.cache;
lock (cache) {
string val;
if (!cache.TryGet(key, out val))
{
// go through all items that have the correct hash
while (++m < index.Length && index[m].HashCode == hashcode)
{
val = LoadDocumentation(key, index[m].PositionInFile);
if (val != null)
{
break;
}
}
// cache the result (even if it is null)
cache.Add(key, val);
}
return(val);
}
}