Normal uproot.open uses new 1 MB chunking and 100 MB cache; uproot.nu…

…mentries uses old 32 kB chunking and 1 MB cache. uproot.numentries skips streamer-reading, which is most of the beginning-of-file reading, and stops early in TTree-metadata-reading; it should typically read 2-3 32 kB chunks (64-96 kB) per file.

uproot/tree.py

@@ -2023,7 +2023,7 @@ def daskframe(path, treepath, branches=None, namedecode="utf-8", entrysteps=floa
 
 ################################################################ for quickly getting numentries
 
-def numentries(path, treepath, total=True, localsource=MemmapSource.defaults, xrootdsource=XRootDSource.defaults, httpsource=HTTPSource.defaults, executor=None, blocking=True, **options):
+def numentries(path, treepath, total=True, localsource=MemmapSource.defaults, xrootdsource={"timeout": None, "chunkbytes": 32*1024, "limitbytes": 1024**2, "parallel": False}, httpsource={"chunkbytes": 32*1024, "limitbytes": 1024**2, "parallel": False}, executor=None, blocking=True, **options):
     if isinstance(path, string_types):
         paths = _filename_explode(path)
     else: