Only import modules as needed

In the case of viz, the results in errors about not having
pycairo and pygtk potentially being printed only if the user actually
uses the -v flag

1 files changed, 14 insertions, 15 deletions

diff --git a/unit-trace b/unit-trace
index 43f752b..f56344f 100755
--- a/unit-trace
+++ b/unit-trace
@@ -9,21 +9,6 @@
 # Setup
 ################################################################################
 
-# Import the modules we need. You should not need to know about
-# their internals.
-import unit_trace
-from unit_trace import trace_reader
-from unit_trace import sanitizer
-from unit_trace import gedf_test
-from unit_trace import gedf_inversion_stat_printer
-from unit_trace import stdout_printer
-from unit_trace import progress
-from unit_trace import skipper
-from unit_trace import maxer
-from unit_trace import earliest
-from unit_trace import latest
-from unit_trace import viz
-
 # Get trace files from command line arguments
 from optparse import OptionParser
 usage = "usage: %prog [options] <one or more trace files>"
@@ -58,36 +43,47 @@ if len(traces) < 1:
 # Pipeline
 ################################################################################
 
+# Import the unit_trace module
+import unit_trace
+
 # Read events from traces
+from unit_trace import trace_reader
 stream = trace_reader.trace_reader(traces)
 
 # Skip over records
 if options.skipnum > 0:
+    from unit_trace import skipper
     stream = skipper.skipper(stream, options.skipnum)
 
 # Enforce max number of records to parse
 if options.maxnum > 0:
+    from unit_trace import maxer
     stream = maxer.maxer(stream, options.maxnum)
 
 # Enfore earliest timestamp
 if options.earliest > 0:
+    from unit_trace import earliest
     stream = earliest.earliest(stream,options.earliest)
 
 # Enfore latest timestamp
 if options.latest > 0:
+    from unit_trace import latest
     stream = latest.latest(stream,options.latest)
 
 # Filter out garbage events
 if options.clean is True:
+    from unit_trace import sanitizer
     stream = sanitizer.sanitizer(stream)
 
 # Display progress information using stderr
 # e.g. # records completed so far, total time, etc.
 if options.progress is True:
+    from unit_trace import progress
     stream = progress.progress(stream)
 
 # Produce G-EDF error records
 if options.gedf is True:
+    from unit_trace import gedf_test
     stream = gedf_test.gedf_test(stream)
 
 # Filter some records out
@@ -106,6 +102,7 @@ stream1, stream2, stream3 = itertools.tee(stream,3)
 
 # Call standard out printer
 if options.stdout is True:
+    from unit_trace import stdout_printer
     stdout_printer.stdout_printer(stream1)
 
 # Print G_EDF inversion statistics
@@ -115,8 +112,10 @@ if options.num_inversions > -1:
         sys.stderr.write("You must enable the G-EDF test module to print" +
             " G-EDF inversion statistics\n")
     else:
+        from unit_trace import gedf_inversion_stat_printer
         gedf_inversion_stat_printer.gedf_inversion_stat_printer(stream2,options.num_inversions)
 
 # Call visualizer
 if options.visualize is True:
+    from unit_trace import viz
     viz.visualizer.visualizer(stream3)