Add ability to overwrite file retention level for specific executable…

…s from config (gwastro#4435)

* Add ability to overwrite file retention level for specific instances

* Allow different retention levels rather than juts not keeping

* CC

* Global and Executable retention levels are not the same

* Fix incorrect indent

pycbc/workflow/core.py

@@ -61,6 +61,7 @@ def make_analysis_dir(path):
 
 class Executable(pegasus_workflow.Executable):
     # These are the file retention levels
+    DO_NOT_KEEP = 0
     INTERMEDIATE_PRODUCT = 1
     ALL_TRIGGERS = 2
     MERGED_TRIGGERS = 3
@@ -147,6 +148,15 @@ def __init__(self, cp, name, ifos=None, out_dir=None, tags=None,
         self.update_output_directory(out_dir=out_dir)
 
         # Determine the level at which output files should be kept
+        if cp.has_option_tags('pegasus_profile-%s' % name,
+                              'pycbc|retention_level', tags):
+            # Get the retention_level from the config file
+            # This method allows us to use the retention levels
+            # defined above
+            cfg_ret_level = cp.get_opt_tags('pegasus_profile-%s' % name,
+                    'pycbc|retention_level', tags)
+            self.current_retention_level = getattr(self, cfg_ret_level)
+
         self.update_current_retention_level(self.current_retention_level)
 
         # Should I reuse this executable?