fw/output: add metadata attribute to Result

Metadata is a key-value mapping for arbitrary data, similar to
classifiers. Unlike classifiers, metadata does not directly relate to
the results of the execution, but to the execution itself, and typically
would not be processed by Output Processors in the same way as
classifiers. Metadata can also be a lot more free-form in it's value
structure; while classifier values are simple scalars, metadata values
can be arbitrary POD structures.

wa/framework/execution.py

@@ -222,6 +222,12 @@ class ExecutionContext(object):
     def add_event(self, message):
         self.output.add_event(message)
 
+    def add_metadata(self, key, *args, **kwargs):
+        self.output.add_metadata(key, *args, **kwargs)
+
+    def update_metadata(self, key, *args):
+        self.output.update_metadata(key, *args)
+
     def take_screenshot(self, filename):
         filepath = self._get_unique_filepath(filename)
         self.tm.target.capture_screen(filepath)

wa/framework/output.py

@@ -2,7 +2,7 @@ import logging
 import os
 import shutil
 from collections import OrderedDict
-from copy import copy
+from copy import copy, deepcopy
 from datetime import datetime
 
 from wa.framework.configuration.core import JobSpec, Status
@@ -11,7 +11,7 @@ from wa.framework.exception import HostError
 from wa.framework.run import RunState, RunInfo
 from wa.framework.target.info import TargetInfo
 from wa.utils.misc import touch, ensure_directory_exists
-from wa.utils.serializer import write_pod, read_pod
+from wa.utils.serializer import write_pod, read_pod, is_pod
 from wa.utils.types import enum, numeric
 
 
@@ -129,6 +129,12 @@ class Output(object):
         artifact = self.get_artifact(name)
         return self.get_path(artifact.path)
 
+    def add_metadata(self, key, *args, **kwargs):
+        self.result.add_metadata(key, *args, **kwargs)
+
+    def update_metadata(self, key, *args):
+        self.result.update_metadata(key, *args)
+
     def __repr__(self):
         return '<{} {}>'.format(self.__class__.__name__,
                                 os.path.basename(self.basepath))
@@ -313,6 +319,7 @@ class Result(object):
         instance.artifacts = [Artifact.from_pod(a) for a in pod['artifacts']]
         instance.events = [Event.from_pod(e) for e in pod['events']]
         instance.classifiers = pod.get('classifiers', OrderedDict())
+        instance.metadata = pod.get('metadata', OrderedDict())
         return instance
 
     def __init__(self):
@@ -322,6 +329,7 @@ class Result(object):
         self.artifacts = []
         self.events = []
         self.classifiers = OrderedDict()
+        self.metadata = OrderedDict()
 
     def add_metric(self, name, value, units=None, lower_is_better=False,
                    classifiers=None):
@@ -350,6 +358,54 @@ class Result(object):
                 return artifact
         raise HostError('Artifact "{}" not found'.format(name))
 
+    def add_metadata(self, key, *args, **kwargs):
+        force = kwargs.pop('force', False)
+        if kwargs:
+            msg = 'Unexpected keyword arguments: {}'
+            raise ValueError(msg.format(kwargs))
+
+        if key in self.metadata and not force:
+            msg = 'Metadata with key "{}" already exists.'
+            raise ValueError(msg.format(key))
+
+        if len(args) == 1:
+            value = args[0]
+        elif len(args) == 2:
+            value = {args[0]: args[1]}
+        elif not args:
+            value = None
+        else:
+            raise ValueError("Unexpected arguments: {}".format(args))
+
+        self.metadata[key] = value
+
+    def update_metadata(self, key, *args):
+        if not args:
+            del self.metadata[key]
+            return
+
+        if key not in self.metadata:
+            return self.add_metadata(key, *args)
+
+        if hasattr(self.metadata[key], 'iteritems'):
+            if len(args) == 2:
+                self.metadata[key][args[0]] = args[1]
+            elif len(args) > 2:  # assume list of key-value pairs
+                for k, v in args:
+                    self.metadata[key][k] = v
+            elif hasattr(args[0], 'iteritems'):
+                for k, v in args[0].iteritems():
+                    self.metadata[key][k] = v
+            else:
+                raise ValueError('Invalid value for key "{}": {}'.format(key, args))
+
+        elif isiterable(self.metadata[key]):
+            self.metadata[key].extend(args)
+        else:   # scalar
+            if len(args) > 1:
+                raise ValueError('Invalid value for key "{}": {}'.format(key, args))
+            self.metadata[key] = args[0]
+
     def to_pod(self):
         return dict(
             status=str(self.status),
@@ -357,6 +413,7 @@ class Result(object):
             artifacts=[a.to_pod() for a in self.artifacts],
             events=[e.to_pod() for e in self.events],
             classifiers=copy(self.classifiers),
+            metadata=deepcopy(self.metadata),
         )