# HG changeset patch
# User brett
# Date 1195835610 18000
# Node ID 4bf2508d9b9e77f45f4aef3a3a11ab67db6a5b32
# Parent  957b402d4b90daf65746ee7474f81e6d51a7b111
[svn] Small optimization to be nice to the system: don't try a given extractor
more than once.

diff -r 957b402d4b90 -r 4bf2508d9b9e scripts/dtrx
--- a/scripts/dtrx	Fri Nov 23 11:24:58 2007 -0500
+++ b/scripts/dtrx	Fri Nov 23 11:33:30 2007 -0500
@@ -30,6 +30,8 @@
 import textwrap
 import traceback
 
+from sets import Set
+
 VERSION = "5.0"
 VERSION_BANNER = """dtrx version %s
 Copyright (c) 2006, 2007 Brett Smith <brettcsmith@brettcsmith.org>
@@ -681,12 +683,21 @@
         return extractor(self.filename, encoding)
 
     def get_extractor(self):
+        tried_types = Set()
+        # As smart as it is, the magic test can't go first, because at least
+        # on my system it just recognizes gem files as tar files.  I guess
+        # it's possible for the opposite problem to occur -- where the mimetype
+        # or extension suggests something less than ideal -- but it seems less
+        # likely so I'm sticking with this.
         for func_name in ('mimetype', 'extension', 'magic'):
             logger.debug("getting extractors by %s" % (func_name,))
             extractor_types = \
                             getattr(self, 'try_by_' + func_name)(self.filename)
             logger.debug("done getting extractors")
             for ext_args in extractor_types:
+                if ext_args in tried_types:
+                    continue
+                tried_types.add(ext_args)
                 logger.debug("trying %s extractor from %s" %
                              (ext_args, func_name))
                 yield self.build_extractor(*ext_args)