System.Text.RegularExpressions.RegexRunner.InitMatch C# (CSharp) Method

        private void InitMatch()
        {
            // Use a hashtable'ed Match object if the capture numbers are sparse

            if (runmatch == null)
            {
                if (runregex.caps != null)
                    runmatch = new MatchSparse(runregex, runregex.caps, runregex.capsize, runtext, runtextbeg, runtextend - runtextbeg, runtextstart);
                else
                    runmatch = new Match(runregex, runregex.capsize, runtext, runtextbeg, runtextend - runtextbeg, runtextstart);
            }
            else
            {
                runmatch.Reset(runregex, runtext, runtextbeg, runtextend, runtextstart);
            }

            // 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. (we used to test _trackcount != 0)

            if (runcrawl != null)
            {
                runtrackpos = runtrack.Length;
                runstackpos = runstack.Length;
                runcrawlpos = runcrawl.Length;
                return;
            }

            InitTrackCount();

            int tracksize = runtrackcount * 8;
            int 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;
        }