one datetime formatter to rule them all

# Conflicts:
#	src/borg/helpers.py

docs/internals/frontends.rst

@@ -209,8 +209,9 @@ Standard output
 *stdout* is different and more command-dependent than logging. Commands like :ref:`borg_info`, :ref:`borg_create`
 and :ref:`borg_list` implement a ``--json`` option which turns their regular output into a single JSON object.
 
-Dates are formatted according to ISO-8601 with the strftime format string '%a, %Y-%m-%d %H:%M:%S',
-e.g. *Sat, 2016-02-25 23:50:06*.
+Dates are formatted according to ISO-8601 in local time. Neither an explicit time zone nor microseconds
+are specified *at this time* (subject to change). The equivalent strftime format string is '%Y-%m-%dT%H:%M:%S',
+e.g. 2017-08-07T12:27:20.
 
 The root object at least contains a *repository* key with an object containing:
 
@@ -267,7 +268,7 @@ Example *borg info* output::
         },
         "repository": {
             "id": "0cbe6166b46627fd26b97f8831e2ca97584280a46714ef84d2b668daf8271a23",
-            "last_modified": "Mon, 2017-02-27 21:21:58",
+            "last_modified": "2017-08-07T12:27:20",
             "location": "/home/user/testrepo"
         },
         "security_dir": "/home/user/.config/borg/security/0cbe6166b46627fd26b97f8831e2ca97584280a46714ef84d2b668daf8271a23",
@@ -328,7 +329,7 @@ Example of a simple archive listing (``borg list --last 1 --json``)::
             {
                 "id": "80cd07219ad725b3c5f665c1dcf119435c4dee1647a560ecac30f8d40221a46a",
                 "name": "host-system-backup-2017-02-27",
-                "start": "Mon, 2017-02-27 21:21:52"
+                "start": "2017-08-07T12:27:20"
             }
         ],
         "encryption": {
@@ -336,7 +337,7 @@ Example of a simple archive listing (``borg list --last 1 --json``)::
         },
         "repository": {
             "id": "0cbe6166b46627fd26b97f8831e2ca97584280a46714ef84d2b668daf8271a23",
-            "last_modified": "Mon, 2017-02-27 21:21:58",
+            "last_modified": "2017-08-07T12:27:20",
             "location": "/home/user/repository"
         }
     }
@@ -354,14 +355,14 @@ The same archive with more information (``borg info --last 1 --json``)::
                 ],
                 "comment": "",
                 "duration": 5.641542,
-                "end": "Mon, 2017-02-27 21:21:58",
+                "end": "2017-02-27T12:27:20",
                 "hostname": "host",
                 "id": "80cd07219ad725b3c5f665c1dcf119435c4dee1647a560ecac30f8d40221a46a",
                 "limits": {
                     "max_archive_size": 0.0001330855110409714
                 },
                 "name": "host-system-backup-2017-02-27",
-                "start": "Mon, 2017-02-27 21:21:52",
+                "start": "2017-02-27T12:27:20",
                 "stats": {
                     "compressed_size": 1880961894,
                     "deduplicated_size": 2791,
@@ -387,7 +388,7 @@ The same archive with more information (``borg info --last 1 --json``)::
         },
         "repository": {
             "id": "0cbe6166b46627fd26b97f8831e2ca97584280a46714ef84d2b668daf8271a23",
-            "last_modified": "Mon, 2017-02-27 21:21:58",
+            "last_modified": "2017-08-07T12:27:20",
             "location": "/home/user/repository"
         }
     }
@@ -405,8 +406,8 @@ Refer to the *borg list* documentation for the available keys and their meaning.
 
 Example (excerpt) of ``borg list --json-lines``::
 
-    {"type": "d", "mode": "drwxr-xr-x", "user": "user", "group": "user", "uid": 1000, "gid": 1000, "path": "linux", "healthy": true, "source": "", "linktarget": "", "flags": null, "isomtime": "Sat, 2016-05-07 19:46:01", "size": 0}
-    {"type": "d", "mode": "drwxr-xr-x", "user": "user", "group": "user", "uid": 1000, "gid": 1000, "path": "linux/baz", "healthy": true, "source": "", "linktarget": "", "flags": null, "isomtime": "Sat, 2016-05-07 19:46:01", "size": 0}
+    {"type": "d", "mode": "drwxr-xr-x", "user": "user", "group": "user", "uid": 1000, "gid": 1000, "path": "linux", "healthy": true, "source": "", "linktarget": "", "flags": null, "isomtime": "2017-02-27T12:27:20", "size": 0}
+    {"type": "d", "mode": "drwxr-xr-x", "user": "user", "group": "user", "uid": 1000, "gid": 1000, "path": "linux/baz", "healthy": true, "source": "", "linktarget": "", "flags": null, "isomtime": "2017-02-27T12:27:20", "size": 0}
 
 .. _msgid:
 

src/borg/archive.py

@@ -33,7 +33,7 @@ from .helpers import ChunkIteratorFileWrapper, open_item
 from .helpers import Error, IntegrityError, set_ec
 from .helpers import uid2user, user2uid, gid2group, group2gid
 from .helpers import parse_timestamp, to_localtime
-from .helpers import format_time, format_timedelta, format_file_size, file_status, FileSize
+from .helpers import OutputTimestamp, format_timedelta, format_file_size, file_status, FileSize
 from .helpers import safe_encode, safe_decode, make_path_safe, remove_surrogates
 from .helpers import StableDict
 from .helpers import bin_to_hex
@@ -380,8 +380,8 @@ class Archive:
         info = {
             'name': self.name,
             'id': self.fpr,
-            'start': format_time(to_localtime(start)),
-            'end': format_time(to_localtime(end)),
+            'start': OutputTimestamp(start),
+            'end': OutputTimestamp(end),
             'duration': (end - start).total_seconds(),
             'stats': stats.as_dict(),
             'limits': {
@@ -410,8 +410,8 @@ Number of files: {0.stats.nfiles}
 Utilization of max. archive size: {csize_max:.0%}
 '''.format(
             self,
-            start=format_time(to_localtime(self.start.replace(tzinfo=timezone.utc))),
-            end=format_time(to_localtime(self.end.replace(tzinfo=timezone.utc))),
+            start=OutputTimestamp(self.start.replace(tzinfo=timezone.utc)),
+            end=OutputTimestamp(self.end.replace(tzinfo=timezone.utc)),
             csize_max=self.cache.chunks[self.id].csize / MAX_DATA_SIZE)
 
     def __repr__(self):

src/borg/helpers/parseformat.py

@@ -18,7 +18,7 @@ logger = create_logger()
 
 from .errors import Error
 from .fs import get_keys_dir
-from .time import format_time, isoformat_time, to_localtime, safe_timestamp, safe_s
+from .time import OutputTimestamp, format_time, to_localtime, safe_timestamp, safe_s
 from .usergroup import uid2user
 from .. import __version__ as borg_version
 from .. import __version_tuple__ as borg_version_tuple
@@ -549,12 +549,11 @@ class ArchiveFormatter(BaseFormatter):
         if self.json:
             self.item_data = {}
             self.format_item = self.format_item_json
-            self.format_time = self.format_time_json
         else:
             self.item_data = static_keys
 
     def format_item_json(self, item):
-        return json.dumps(self.get_item_data(item)) + '\n'
+        return json.dumps(self.get_item_data(item), cls=BorgJsonEncoder) + '\n'
 
     def get_item_data(self, archive_info):
         self.name = archive_info.name
@@ -588,12 +587,7 @@ class ArchiveFormatter(BaseFormatter):
         return self.format_time(self.archive.ts_end)
 
     def format_time(self, ts):
-        t = to_localtime(ts)
-        return format_time(t)
-
-    def format_time_json(self, ts):
-        t = to_localtime(ts)
-        return isoformat_time(t)
+        return OutputTimestamp(ts)
 
 
 class ItemFormatter(BaseFormatter):
@@ -669,7 +663,6 @@ class ItemFormatter(BaseFormatter):
         if self.json_lines:
             self.item_data = {}
             self.format_item = self.format_item_json
-            self.format_time = self.format_time_json
         else:
             self.item_data = static_keys
         self.format = partial_format(format, static_keys)
@@ -681,19 +674,19 @@ class ItemFormatter(BaseFormatter):
             'dcsize': partial(self.sum_unique_chunks_metadata, lambda chunk: chunk.csize),
             'num_chunks': self.calculate_num_chunks,
             'unique_chunks': partial(self.sum_unique_chunks_metadata, lambda chunk: 1),
-            'isomtime': partial(self.format_time, 'mtime'),
-            'isoctime': partial(self.format_time, 'ctime'),
-            'isoatime': partial(self.format_time, 'atime'),
-            'mtime': partial(self.time, 'mtime'),
-            'ctime': partial(self.time, 'ctime'),
-            'atime': partial(self.time, 'atime'),
+            'isomtime': partial(self.format_iso_time, 'mtime'),
+            'isoctime': partial(self.format_iso_time, 'ctime'),
+            'isoatime': partial(self.format_iso_time, 'atime'),
+            'mtime': partial(self.format_time, 'mtime'),
+            'ctime': partial(self.format_time, 'ctime'),
+            'atime': partial(self.format_time, 'atime'),
         }
         for hash_function in hashlib.algorithms_guaranteed:
             self.add_key(hash_function, partial(self.hash_item, hash_function))
         self.used_call_keys = set(self.call_keys) & self.format_keys
 
     def format_item_json(self, item):
-        return json.dumps(self.get_item_data(item)) + '\n'
+        return json.dumps(self.get_item_data(item), cls=BorgJsonEncoder) + '\n'
 
     def add_key(self, key, callable_with_item):
         self.call_keys[key] = callable_with_item
@@ -768,15 +761,10 @@ class ItemFormatter(BaseFormatter):
         return hash.hexdigest()
 
     def format_time(self, key, item):
-        t = self.time(key, item)
-        return format_time(t)
-
-    def format_time_json(self, key, item):
-        t = self.time(key, item)
-        return isoformat_time(t)
+        return OutputTimestamp(safe_timestamp(item.get(key) or item.mtime))
 
-    def time(self, key, item):
-        return safe_timestamp(item.get(key) or item.mtime)
+    def format_iso_time(self, key, item):
+        return self.format_time(key, item).to_json()
 
 
 def file_status(mode):
@@ -887,6 +875,8 @@ class BorgJsonEncoder(json.JSONEncoder):
             return {
                 'stats': o.stats(),
             }
+        if callable(getattr(o, 'to_json', None)):
+            return o.to_json()
         return super().default(o)
 
 
@@ -899,7 +889,7 @@ def basic_json_data(manifest, *, cache=None, extra=None):
             'mode': key.ARG_NAME,
         },
     })
-    data['repository']['last_modified'] = isoformat_time(to_localtime(manifest.last_timestamp.replace(tzinfo=timezone.utc)))
+    data['repository']['last_modified'] = OutputTimestamp(manifest.last_timestamp.replace(tzinfo=timezone.utc))
     if key.NAME.startswith('key file'):
         data['encryption']['keyfile'] = key.find_key()
     if cache:

src/borg/helpers/time.py

@@ -113,3 +113,19 @@ def format_timedelta(td):
     if td.days:
         txt = '%d days %s' % (td.days, txt)
     return txt
+
+
+class OutputTimestamp:
+    def __init__(self, ts: datetime):
+        if ts.tzinfo == timezone.utc:
+            ts = to_localtime(ts)
+        self.ts = ts
+
+    def __format__(self, format_spec):
+        return format_time(self.ts)
+
+    def __str__(self):
+        return '{}'.format(self)
+
+    def to_json(self):
+        return isoformat_time(self.ts)

src/borg/testsuite/archiver.py

@@ -1326,6 +1326,8 @@ class ArchiverTestCase(ArchiverTestCaseBase):
         assert isinstance(archive['duration'], float)
         assert len(archive['id']) == 64
         assert 'stats' in archive
+        assert datetime.strptime(archive['start'], ISO_FORMAT)
+        assert datetime.strptime(archive['end'], ISO_FORMAT)
 
     def test_comment(self):
         self.create_regular_file('file1', size=1024 * 80)