using stdout field in cachekey calculation (#532)

Author: kapilkd13

cwltool/draft2tool.py

@@ -244,7 +244,6 @@ def job(self,
         # type: (...) -> Generator[Union[JobBase, CallbackJob], None, None]
 
         jobname = uniquename(kwargs.get("name", shortname(self.tool.get("id", "job"))))
-
         if kwargs.get("cachedir"):
             cacheargs = kwargs.copy()
             cacheargs["outdir"] = "/out"
@@ -270,6 +269,8 @@ def job(self,
                 cmdline = ["docker", "run", dockerimg] + cmdline
             keydict = {u"cmdline": cmdline}
 
+            if "stdout" in self.tool:
+                keydict["stdout"] = self.tool["stdout"]
             for location, f in cachebuilder.pathmapper.items():
                 if f.type == "File":
                     checksum = next((e['checksum'] for e in cachebuilder.files

cwltool/load_tool.py

@@ -6,6 +6,8 @@
 import os
 import re
 import uuid
+import hashlib
+import json
 from typing import Any, Callable, Dict, List, Text, Tuple, Union, cast
 
 import requests.sessions
@@ -88,7 +90,8 @@ def _convert_stdstreams_to_files(workflowobj):
                         if streamtype in workflowobj:
                             filename = workflowobj[streamtype]
                         else:
-                            filename = Text(uuid.uuid4())
+                            filename = Text(hashlib.sha1(json.dumps(workflowobj,
+                                        sort_keys=True).encode('utf-8')).hexdigest())
                             workflowobj[streamtype] = filename
                         out['type'] = 'File'
                         out['outputBinding'] = {'glob': filename}