// TODO https://github.com/dotnet/runtime/issues/62573: Obsolete this.
/// <summary>
/// This method's body is only kept since it is a protected member that could be called by someone outside
/// the assembly.
/// </summary>
protected internal Match?Scan(Regex regex, string text, int textbeg, int textend, int textstart, int prevlen, bool quick, TimeSpan timeout)
{
InitializeTimeout(timeout);
RegexRunnerMode mode = quick ? RegexRunnerMode.ExistenceRequired : RegexRunnerMode.FullMatchRequired;
// We set runtext before calling InitializeForScan so that runmatch object is initialized with the text
runtext = text;
InitializeForScan(regex, text, textstart, mode);
// InitializeForScan will default runtextstart and runtextend to 0 and length of string
// since it is configured to work over a sliced portion of text so we adjust those values.
runtextstart = textstart;
runtextend = textend;
// Configure the additional value to "bump" the position along each time we loop around
// to call FindFirstChar again, as well as the stopping position for the loop. We generally
// bump by 1 and stop at textend, but if we're examining right-to-left, we instead bump
// by -1 and stop at textbeg.
int bump = 1, stoppos = textend;
if (regex.RightToLeft)
{
bump = -1;
stoppos = textbeg;
}
// If previous match was empty or failed, advance by one before matching.
if (prevlen == 0)
{
if (textstart == stoppos)
{
return(Match.Empty);
}
runtextpos += bump;
}
Match match = InternalScan(regex, textbeg, textend);
runtext = null; //drop reference
if (match.FoundMatch)
{
if (quick)
{
return(null);
}
runmatch = null;
match.Tidy(runtextpos, 0, mode);
}
else
{
runmatch !.Text = null;
}
return(match);
}
internal void InitializeForScan(Regex regex, ReadOnlySpan <char> text, int textstart, RegexRunnerMode mode)
{
// Store remaining arguments into fields now that we're going to start the scan.
// These are referenced by the derived runner.
_mode = mode;
runregex = regex;
runtextstart = textstart;
runtextbeg = 0;
runtextend = text.Length;
runtextpos = textstart;
Match?m = runmatch;
if (m is null)
{
// Use a hashtabled Match object if the capture numbers are sparse
runmatch = runregex !.caps is null ?
new Match(runregex, runregex.capsize, runtext, text.Length) :
new MatchSparse(runregex, runregex.caps, runregex.capsize, runtext, text.Length);
}
else
{
m.Reset(runtext, text.Length);
}
// Note we test runcrawl, because it is the last one to be allocated
// If there is an alloc failure in the middle of the three allocations,
// we may still return to reuse this instance, and we want to behave
// as if the allocations didn't occur.
if (runcrawl != null)
{
runtrackpos = runtrack !.Length;
runstackpos = runstack !.Length;
runcrawlpos = runcrawl.Length;
return;
}
// Everything above runs once per match.
// Everything below runs once per runner.
InitTrackCount();
int stacksize;
int tracksize = stacksize = runtrackcount * 8;
if (tracksize < 32)
{
tracksize = 32;
}
if (stacksize < 16)
{
stacksize = 16;
}
runtrack = new int[tracksize];
runtrackpos = tracksize;
runstack = new int[stacksize];
runstackpos = stacksize;
runcrawl = new int[32];
runcrawlpos = 32;
}