Backport: Allow db job modification and some fixes (#297)

- Ability to modify Database Jobs
- New attributes for a Database Job:
    - extra
    - failed_node
- Now possible to initialize a pyslurm.db.Jobs collection with existing job
  ids or pyslurm.db.Job objects

- Fixes a problem that prevented loading specific Jobs from the Database if
  the following two conditions were met:
    - no start/end time was specified
    - the Job was older than a day

- create a _get_exit_code helper function to reduce duplicate code in various places when checking for exit-code or exit-signal of a Job or JobStep

Author: tazend

pyslurm/core/job/job.pyx

@@ -48,6 +48,7 @@ from pyslurm.utils.helpers import (
     _getpwall_to_dict,
     instance_to_dict,
     _sum_prop,
+    _get_exit_code,
 )
 
 
@@ -785,35 +786,23 @@ cdef class Job:
 
     @property
     def derived_exit_code(self):
-        if (self.ptr.derived_ec == slurm.NO_VAL
-                or not WIFEXITED(self.ptr.derived_ec)):
-            return None
-
-        return WEXITSTATUS(self.ptr.derived_ec)
+        ec, _ = _get_exit_code(self.ptr.derived_ec)
+        return ec
 
     @property
     def derived_exit_code_signal(self):
-        if (self.ptr.derived_ec == slurm.NO_VAL
-                or not WIFSIGNALED(self.ptr.derived_ec)): 
-            return None
-
-        return WTERMSIG(self.ptr.derived_ec)
+        _, sig = _get_exit_code(self.ptr.derived_ec)
+        return sig
 
     @property
     def exit_code(self):
-        if (self.ptr.exit_code == slurm.NO_VAL
-                or not WIFEXITED(self.ptr.exit_code)):
-            return None
-
-        return WEXITSTATUS(self.ptr.exit_code)
+        ec, _ = _get_exit_code(self.ptr.exit_code)
+        return ec
 
     @property
     def exit_code_signal(self):
-        if (self.ptr.exit_code == slurm.NO_VAL
-                or not WIFSIGNALED(self.ptr.exit_code)):
-            return None
-
-        return WTERMSIG(self.ptr.exit_code)
+        _, sig = _get_exit_code(self.ptr.exit_code)
+        return sig
 
     @property
     def batch_constraints(self):

pyslurm/db/job.pxd

@@ -39,6 +39,8 @@ from pyslurm.slurm cimport (
     slurmdb_job_cond_def_start_end,
     slurm_job_state_string,
     slurm_job_reason_string,
+    slurmdb_create_job_rec,
+    slurmdb_job_modify,
 )
 from pyslurm.db.util cimport (
     SlurmList,
@@ -162,8 +164,17 @@ cdef class Job:
         job_id (int, optional=0):
             An Integer representing a Job-ID.
 
-    Raises:
-        MemoryError: If malloc fails to allocate memory.
+    Other Parameters:
+        admin_comment (str):
+            Admin comment for the Job.
+        comment (str):
+            Comment for the Job
+        wckey (str):
+            Name of the WCKey for this Job
+        derived_exit_code (int):
+            Highest exit code of all the Job steps
+        extra (str):
+            Arbitrary string that can be stored with a Job.
 
     Attributes:
         steps (pyslurm.db.JobSteps):
@@ -209,10 +220,14 @@ cdef class Job:
             When the Job became eligible to run, as a unix timestamp
         end_time (int):
             When the Job ended, as a unix timestamp
+        extra (str):
+            Arbitrary string that can be stored with a Job.
         exit_code (int):
             Exit code of the job script or salloc.
         exit_code_signal (int):
             Signal of the exit code for this Job.
+        failed_node (str):
+            Name of the failed node that caused the job to get killed.
         group_id (int):
             ID of the group for this Job
         group_name (str):