/*
* Aho-Corasick
*
* q = root
* FOR i = 1 TO n
* WHILE q != fail AND g(q, text[i]) == fail
* q = h(q)
* ENDWHILE
* IF q == fail
* q = root
* ELSE
* q = g(q, text[i])
* ENDIF
* IF isElement(q, final)
* RETURN TRUE
* ENDIF
* ENDFOR
* RETURN FALSE
*/
public IList <TrieHit> FindMatches(string haystack)
{
List <TrieHit> matches = new List <TrieHit> ();
TrieState q = root;
TrieMatch m = null;
int idx = 0, start_idx = 0, last_idx = 0;
while (idx < haystack.Length)
{
char c = haystack [idx++];
if (!case_sensitive)
{
c = Char.ToLower(c);
}
while (q != null)
{
m = FindMatchAtState(q, c);
if (m == null)
{
q = q.Fail;
}
else
{
break;
}
}
if (q == root)
{
start_idx = last_idx;
}
if (q == null)
{
q = root;
start_idx = idx;
}
else if (m != null)
{
q = m.State;
// Got a match!
if (q.Final != 0)
{
string key = haystack.Substring(start_idx,
idx - start_idx);
TrieHit hit =
new TrieHit(start_idx, idx, key, q.Id);
matches.Add(hit);
}
}
last_idx = idx;
}
return(matches);
}
void DoHighlight(TrieHit hit, Gtk.TextIter start, Gtk.TextIter end)
{
// Some of these checks should be replaced with fixes to
// TitleTrie.FindMatches, probably.
if (hit.Value == null)
{
Logger.Debug("DoHighlight: null pointer error for '{0}'.", hit.Key);
return;
}
if (Manager.Find(hit.Key) == null)
{
Logger.Debug("DoHighlight: '{0}' links to non-existing note.", hit.Key);
return;
}
Note hit_note = (Note)hit.Value;
if (String.Compare(hit.Key.ToString(), hit_note.Title.ToString(), true) != 0) // == 0 if same string
{
Logger.Debug("DoHighlight: '{0}' links wrongly to note '{1}'.", hit.Key, hit_note.Title);
return;
}
if (hit_note == this.Note)
{
return;
}
Gtk.TextIter title_start = start;
title_start.ForwardChars(hit.Start);
Gtk.TextIter title_end = start;
title_end.ForwardChars(hit.End);
// Only link against whole words/phrases
if ((!title_start.StartsWord() && !title_start.StartsSentence()) ||
(!title_end.EndsWord() && !title_end.EndsSentence()))
{
return;
}
// Don't create links inside URLs
if (Note.TagTable.HasLinkTag(title_start))
{
return;
}
Logger.Debug("Matching Note title '{0}' at {1}-{2}...",
hit.Key,
hit.Start,
hit.End);
Buffer.RemoveTag(Note.TagTable.BrokenLinkTag, title_start, title_end);
Buffer.ApplyTag(Note.TagTable.LinkTag, title_start, title_end);
}
void HighlightNoteInBlock(Note find_note, Gtk.TextIter start, Gtk.TextIter end)
{
string buffer_text = start.GetText(end).ToLower();
string find_title_lower = find_note.Title.ToLower();
int idx = 0;
while (true)
{
idx = buffer_text.IndexOf(find_title_lower, idx);
if (idx < 0)
{
break;
}
TrieHit hit = new TrieHit(idx,
idx + find_title_lower.Length,
find_title_lower,
find_note);
DoHighlight(hit, start, end);
idx += find_title_lower.Length;
}
}
void HighlightNoteInBlock (Note find_note, Gtk.TextIter start, Gtk.TextIter end)
{
string buffer_text = start.GetText (end).ToLower();
string find_title_lower = find_note.Title.ToLower ();
int idx = 0;
while (true) {
idx = buffer_text.IndexOf (find_title_lower, idx);
if (idx < 0)
break;
TrieHit hit = new TrieHit (idx,
idx + find_title_lower.Length,
find_title_lower,
find_note);
DoHighlight (hit, start, end);
idx += find_title_lower.Length;
}
}
void DoHighlight (TrieHit hit, Gtk.TextIter start, Gtk.TextIter end)
{
// Some of these checks should be replaced with fixes to
// TitleTrie.FindMatches, probably.
if (hit.Value == null) {
Logger.Debug ("DoHighlight: null pointer error for '{0}'." , hit.Key);
return;
}
if (Manager.Find(hit.Key) == null) {
Logger.Debug ("DoHighlight: '{0}' links to non-existing note." , hit.Key);
return;
}
Note hit_note = (Note) hit.Value;
if (String.Compare (hit.Key.ToString(), hit_note.Title.ToString(), true ) != 0) { // == 0 if same string
Logger.Debug ("DoHighlight: '{0}' links wrongly to note '{1}'." , hit.Key, hit_note.Title);
return;
}
if (hit_note == this.Note)
return;
Gtk.TextIter title_start = start;
title_start.ForwardChars (hit.Start);
Gtk.TextIter title_end = start;
title_end.ForwardChars (hit.End);
// Only link against whole words/phrases
if ((!title_start.StartsWord () && !title_start.StartsSentence ()) ||
(!title_end.EndsWord() && !title_end.EndsSentence()))
return;
// Don't create links inside URLs
if (Note.TagTable.HasLinkTag (title_start))
return;
Logger.Debug ("Matching Note title '{0}' at {1}-{2}...",
hit.Key,
hit.Start,
hit.End);
Buffer.RemoveTag (Note.TagTable.BrokenLinkTag, title_start, title_end);
Buffer.ApplyTag (Note.TagTable.LinkTag, title_start, title_end);
}
