[Piglit] [PATCH 15/19] python: Allow additional backends

[Dylan Baker]

This adds the boilerplate code required to make multiple backends
actually work, a backend option and a helper to facilitate getting the
requested backend.

Signed-off-by: Dylan Baker <dylanx.c.baker at intel.com>
---
 framework/programs/run.py        | 23 ++++++++++++++---------
 framework/results.py             | 20 ++++++++++++++++++--
 framework/tests/results_tests.py | 20 ++++++++++++++++++--
 3 files changed, 50 insertions(+), 13 deletions(-)

diff --git a/framework/programs/run.py b/framework/programs/run.py
index 8493611..8b7045d 100644
--- a/framework/programs/run.py
+++ b/framework/programs/run.py
@@ -108,6 +108,10 @@ def _run_parser(input_):
                         metavar="<regex>",
                         help="Exclude matching tests "
                              "(can be used more than once)")
+    parser.add_argument('-b', '--backend',
+                        default='json',
+                        choices=framework.results.BACKENDS,
+                        help='select a results backend to use')
     conc_parser = parser.add_mutually_exclusive_group()
     conc_parser.add_argument('-c', '--all-concurrent',
                              action="store_const",
@@ -219,9 +223,8 @@ def run(input_):
     options['env'] = core.collect_system_info()
 
     # Begin json.
-    result_filepath = path.join(args.results_path, 'results.json')
-    backend = framework.results.JSONWriter(
-        result_filepath,
+    backend = framework.results.get_backend(args.backend)(
+        args.results_path,
         options,
         file_fsync=opts.sync)
 
@@ -239,7 +242,7 @@ def run(input_):
     backend.finalize({'time_elapsed': results.time_elapsed})
 
     print('Thank you for running Piglit!\n'
-          'Results have been written to ' + result_filepath)
+          'Results have been written to ' + args.results_path)
 
 
 def resume(input_):
@@ -270,10 +273,12 @@ def resume(input_):
     opts.env['PIGLIT_PLATFORM'] = results.options['platform']
 
     results.options['env'] = core.collect_system_info()
-    results_path = path.join(args.results_path, 'results.json')
-    backend = framework.results.JSONWriter(results_path,
-                                           results.options,
-                                           file_fsync=opts.sync)
+
+    # Resume only works with the JSON backend
+    backend = framework.results.get_backend('json')(
+        args.results_path,
+        results.options,
+        file_fsync=opts.sync)
 
     for key, value in results.tests.iteritems():
         backend.write_test(key, value)
@@ -290,4 +295,4 @@ def resume(input_):
     backend.finalize()
 
     print("Thank you for running Piglit!\n"
-          "Results have ben wrriten to {0}".format(results_path))
+          "Results have ben wrriten to {0}".format(args.results_path))
diff --git a/framework/results.py b/framework/results.py
index c3aac9f..fcdd154 100644
--- a/framework/results.py
+++ b/framework/results.py
@@ -37,10 +37,14 @@ import framework.status as status
 __all__ = [
     'TestrunResult',
     'TestResult',
-    'JSONWriter',
     'load_results',
+    'get_backend',
+    'BACKENDS',
 ]
 
+# A list of available backends
+BACKENDS = ['json']
+
 # The current version of the JSON results
 CURRENT_JSON_VERSION = 1
 
@@ -178,7 +182,7 @@ class JSONWriter(Backend):
     _LOCK = threading.RLock()
 
     def __init__(self, f, metadata, file_fsync=False):
-        self.file = open(f, 'w')
+        self.file = open(os.path.join(f, 'results.json'), 'w')
         self.fsync = file_fsync
         self.__indent_level = 0
         self.__inhibit_next_indent = False
@@ -579,6 +583,18 @@ def update_results(results, filepath):
     return results
 
 
+def get_backend(backend):
+    """ Returns a BackendInstance based on the string passed """
+    backends = {
+        'json': JSONWriter,
+    }
+
+    # Be sure that we're exporting the same list of backends that we actually
+    # have available
+    assert backends.keys() == BACKENDS
+    return backends[backend]
+
+
 def _update_zero_to_one(results):
     """ Update version zero results to version 1 results
 
diff --git a/framework/tests/results_tests.py b/framework/tests/results_tests.py
index 12b6e80..9f364fa 100644
--- a/framework/tests/results_tests.py
+++ b/framework/tests/results_tests.py
@@ -68,8 +68,8 @@ def test_initialize_jsonwriter():
     arguments
 
     """
-    with utils.with_tempfile('') as tfile:
-        func = results.JSONWriter(tfile, BACKEND_INITIAL_META)
+    with utils.tempdir() as tdir:
+        func = results.JSONWriter(tdir, BACKEND_INITIAL_META)
         assert isinstance(func, results.JSONWriter)
 
 
@@ -165,3 +165,19 @@ def test_update_results_old():
         res = results.update_results(base, f.name)
 
     nt.assert_equal(res.results_version, results.CURRENT_JSON_VERSION)
+
+
+ at utils.nose_generator
+def test_get_backend():
+    """ Generate tests to get various backends """
+    # We use a hand generated list here to ensure that we are getting what we
+    # expect
+    backends = {
+        'json': results.JSONWriter,
+    }
+
+    check = lambda n, i: nt.assert_is(results.get_backend(n), i)
+
+    for name, inst in backends.iteritems():
+        check.description = 'get_backend({0}) returns {0} backend'.format(name)
+        yield check, name, inst
-- 
2.1.0