/// <summary>
/// Preprocesses the search options and returns an opaque object
/// that holds the state needed to efficiently search many times using the search options.
/// Different threads can not share the returned state object. Each thread has to call this method.
/// </summary>
public static SearchState BeginSearch(this Options options, IRegexFactory regexFactory, bool timeboxedMatching = false)
{
SearchState ret = new SearchState()
{
options = options,
contentTypeMask = MessageFlag.ContentTypeMask & options.ContentTypes,
};
if (!string.IsNullOrEmpty(options.Template))
{
if (options.Regexp || useRegexsForSimpleTemplates)
{
ReOptions reOpts = ReOptions.AllowPatternWhitespaces;
if (!options.MatchCase)
{
reOpts |= ReOptions.IgnoreCase;
}
if (options.ReverseSearch)
{
reOpts |= ReOptions.RightToLeft;
}
if (timeboxedMatching)
{
reOpts |= ReOptions.Timeboxed;
}
try
{
ret.re = regexFactory.Create(
options.Regexp ? options.Template : System.Text.RegularExpressions.Regex.Escape(options.Template), reOpts);
}
catch (Exception)
{
throw new TemplateException();
}
}
else
{
if (!options.MatchCase)
{
ret.options.Template = ret.options.Template.ToLower();
}
}
}
return(ret);
}
public static MatchedTextRange?SearchInMessageText(
this SearchState state,
IMessage msg,
int?startTextPosition = null)
{
MessageFlag msgFlags = msg.Flags;
if ((msgFlags & state.contentTypeMask) == 0)
{
return(null);
}
if (!state.options.Scope.ContainsMessage(msg))
{
return(null);
}
StringSlice sourceText = state.options.MessageTextGetter(msg).Text;
return(SearchInText(state, sourceText, startTextPosition));
}
public static MatchedTextRange?SearchInText(
this SearchState state,
StringSlice text,
int?startTextPosition)
{
IRegex re = state.re;
// matched string position
int matchBegin = 0; // index of the first matched char
int matchEnd = 0; // index of following after the last matched one
bool wholeTextMatched = false;
if (!string.IsNullOrEmpty(state.options.Template)) // empty/null template means that text matching isn't required, i.e. match any input
{
int textPos;
if (startTextPosition.HasValue)
{
textPos = startTextPosition.Value;
}
else if (state.options.ReverseSearch)
{
textPos = text.Length;
}
else
{
textPos = 0;
}
for (; ;)
{
if (re != null)
{
if (!re.Match(text, textPos, ref state.searchMatch))
{
return(null);
}
matchBegin = state.searchMatch.Index;
matchEnd = matchBegin + state.searchMatch.Length;
}
else
{
StringComparison cmp = state.options.MatchCase ? StringComparison.CurrentCulture : StringComparison.CurrentCultureIgnoreCase;
int i;
// todo: use running hash
if (state.options.ReverseSearch)
{
i = text.LastIndexOf(state.options.Template, textPos, cmp);
}
else
{
i = text.IndexOf(state.options.Template, textPos, cmp);
}
if (i < 0)
{
return(null);
}
matchBegin = i;
matchEnd = matchBegin + state.options.Template.Length;
}
if (state.options.WholeWord && !IsWordBoundary(text, matchBegin, matchEnd))
{
textPos = state.options.ReverseSearch ? matchBegin : matchEnd;
continue;
}
break;
}
}
else
{
matchBegin = 0;
matchEnd = text.Length;
wholeTextMatched = true;
}
return(new MatchedTextRange(text, matchBegin, matchEnd, wholeTextMatched));
}