initial attempt (not supported by mars client c++)

polytope_server/common/datasource/mars.py

@@ -18,6 +18,7 @@
 # does it submit to any jurisdiction.
 #
 
+import copy
 import logging
 import os
 import tempfile
@@ -113,17 +114,42 @@ def archive(self, request):
 
     def retrieve(self, request):
 
+        r = yaml.safe_load(request.user_request) or {}
+
+        # Do a list first, to see how big the request will be
+        list_r = copy.deepcopy(r)
+        # list_r['output'] = 'cost'
+
+        # Make a temporary file for the request
+        with tempfile.NamedTemporaryFile(delete=False) as tmp:
+            self.request_file = tmp.name
+            logging.info("Writing list request to tempfile {}".format(self.request_file))
+            tmp.write(self.convert_to_mars_request("list", list_r).encode())
+
+        self.subprocess = Subprocess()
+        self.subprocess.run(
+            cmd=[self.command, self.request_file],
+            cwd=os.path.dirname(__file__),
+            env=self.make_env(request),
+        )
+        self.subprocess.finalize(request, "")
+        logging.info(self.subprocess.output)
+        os.unlink(self.request_file)
+
+
+
+
+
         # Open a FIFO for MARS output
         self.fifo = FIFO("MARS-FIFO-" + request.id)
 
         # Parse the user request as YAML, and add the FIFO as target
-        r = yaml.safe_load(request.user_request) or {}
         r["target"] = '"' + self.fifo.path + '"'
 
         # Make a temporary file for the request
         with tempfile.NamedTemporaryFile(delete=False) as tmp:
             self.request_file = tmp.name
-            logging.info("Writing request to tempfile {}".format(self.request_file))
+            logging.info("Writing retrieve request to tempfile {}".format(self.request_file))
             tmp.write(self.convert_to_mars_request("retrieve", r).encode())
 
         # Call MARS