efbfbf: upgrade to Bugs Everywhere Directory v1.5

[sawsim.git] / pysawsim / manager / __init__.py

diff --git a/pysawsim/manager/__init__.py b/pysawsim/manager/__init__.py
index 6bdba75991aa6abe27fe768dda113c447ce09507..30f6e874604f8224f35c41256a49574e2753e453 100644 (file)
--- a/pysawsim/manager/__init__.py
+++ b/pysawsim/manager/__init__.py
@@ -18,12 +18,20 @@
 # Philadelphia PA 19104, USA.
 
 """Functions for running external commands on other hosts.
+
+See the Python wiki_ for a list of parallel processing modules.
+
+.. _wiki: http://wiki.python.org/moin/ParallelProcessing
 """
 
 from .. import invoke as invoke
 from .. import log
 
 
+MANAGERS = ['thread', 'subproc', 'mpi', 'pbs']
+"""Submodules with JobManager subclasses."""
+
+
 class Job (object):
     """Job request structure for `JobManager`.
 
@@ -97,7 +105,7 @@ class Job (object):
         self.data = None
 
     def __str__(self):
-        return '<%s %d>' % (self.__class__.__name__, self.id)
+        return '<%s %s>' % (self.__class__.__name__, self.id)
 
     def __repr__(self):
         return self.__str__()
@@ -131,17 +139,17 @@ class InvokeJob (Job):
 
     >>> j = InvokeJob(id=3, target='missing_command')
     >>> j.run()
-    >>> print j.status
+    >>> print j.status  # doctest: +ELLIPSIS
     Command failed (127):
-      /bin/sh: missing_command: command not found
+      /bin/sh: missing_command: ...not found
     <BLANKLINE>
     <BLANKLINE>
     while executing
       missing_command
     >>> j.data['stdout']
     ''
-    >>> j.data['stderr']
-    '/bin/sh: missing_command: command not found\\n'
+    >>> j.data['stderr']  # doctest: +ELLIPSIS
+    '/bin/sh: missing_command: ...not found\\n'
     """
     def run(self):
         try:
@@ -150,7 +158,7 @@ class InvokeJob (Job):
             self.data = {'stdout':stdout, 'stderr':stderr}
         except invoke.CommandError, e:
             self.status = e
-            self.data = {'stdout':e.stdout, 'stderr':e.stderr}
+            self.data = {'stdout':e.stdout, 'stderr':e.stderr, 'error':e}
 
 
 class JobManager (object):
@@ -197,12 +205,87 @@ class JobManager (object):
                 jobs[id] = self._jobs.pop(id)
         while len(ids) > 0:  # wait for outstanding jobs
             job = self._receive_job()
-            log().debug('receive job %s (%d)' % (job, job.status))
-            job.copy_onto(self._jobs[job.id])
+            self._handle_received_job(job)
             if job.id in ids and job.id in self._jobs:
                 jobs[job.id] = self._jobs.pop(job.id)
                 ids.remove(job.id)
         return jobs
 
+    def _handle_received_job(self, job):
+        log().debug('receive job %s (%s)' % (job, job.status))
+        job.copy_onto(self._jobs[job.id])
+
     def _receive_job(self):
         raise NotImplementedError
+
+
+class IsSubclass (object):
+    """A safe subclass comparator.
+
+    Examples
+    --------
+
+    >>> class A (object):
+    ...     pass
+    >>> class B (A):
+    ...     pass
+    >>> C = 5
+    >>> is_subclass = IsSubclass(A)
+    >>> is_subclass(A)
+    True
+    >>> is_subclass = IsSubclass(A, blacklist=[A])
+    >>> is_subclass(A)
+    False
+    >>> is_subclass(B)
+    True
+    >>> is_subclass(C)
+    False
+    """
+    def __init__(self, base_class, blacklist=None):
+        self.base_class = base_class
+        if blacklist == None:
+            blacklist = []
+        self.blacklist = blacklist
+    def __call__(self, other):
+        try:
+            subclass = issubclass(other, self.base_class)
+        except TypeError:
+            return False
+        if other in self.blacklist:
+            return False
+        return subclass
+
+
+def get_manager(submod=None, defaults=['subproc', 'thread']):
+    """
+    >>> get_manager('thread')
+    <class 'pysawsim.manager.thread.ThreadManager'>
+    >>> get_manager('wookie')
+    Traceback (most recent call last):
+      ...
+    AttributeError: 'module' object has no attribute 'wookie'
+    >>> m = get_manager()
+    >>> issubclass(m, JobManager)
+    True
+    """
+    if submod == None:
+        for submod in defaults:
+            try:
+                m = get_manager(submod)
+            except ImportError:
+                continue
+            if len(m._bugs) > 0:
+                continue
+            return m
+        raise Exception('none of the managers in %s were enabled' % defaults)
+    this_mod = __import__(__name__, fromlist=[submod])
+    sub_mod = getattr(this_mod, submod)
+    if sub_mod._ENABLED == False:
+        raise sub_mod._DISABLING_ERROR
+    class_selector = IsSubclass(base_class=JobManager, blacklist=[JobManager])
+    for x_name in dir(sub_mod):
+        x = getattr(sub_mod, x_name)
+        if class_selector(x) == True:
+            x._bugs = [a for a in dir(sub_mod) if a.startswith('_HAS_BUG_')]
+            return x
+    raise ValueError('no JobManager found in %s' % sub_mod.__name__)