management: introduce replacerelations command

The replacerelations script is used to ingest relations into Patchwork's
patch database. A patch groups file is taken as input, which on each
line contains a space separated list of patchwork ids denoting a
relation. All the existing relations in Patchwork's database are removed
and the relations read from the patch groups file are ingested.

Signed-off-by: Rohit Sarkar <rohitsarkar5398@gmail.com>
[dja: pep8, drop relations directory as empty dirs don't get stored by git,
      comment about how lines are generated.]
Signed-off-by: Daniel Axtens <dja@axtens.net>

docs/deployment/management.rst

@@ -116,6 +116,43 @@ the :ref:`deployment installation guide <deployment-parsemail>`.
 
    input mbox filename. If not supplied, a patch will be read from ``stdin``.
 
+replacerelations
+~~~~~~~~~~~~~~~~
+
+.. program:: manage.py replacerelations
+
+Parse a patch groups file and store any relation found
+
+.. code-block:: shell
+
+    ./manage.py replacerelations <infile>
+
+This is a script used to ingest relations into Patchwork.
+
+A patch groups file contains on each line a list of space separated patch IDs
+of patches that form a relation.
+
+For example, consider the contents of a sample patch groups file::
+
+    1 3 5
+    2
+    7 10 11 12
+
+In this case the script will identify 2 relations, (1, 3, 5) and
+(7, 10, 11, 12). The single patch ID "2" on the second line is ignored as a
+relation always consists of more than 1 patch.
+
+Further, if a patch ID in the patch groups file does not exist in the database
+of the Patchwork instance, that patch ID will be silently ignored while forming
+the relations.
+
+Running this script will remove all existing relations and replace them with
+the relations found in the file.
+
+.. option:: infile
+
+    input patch groups file.
+
 rehash
 ~~~~~~
 

patchwork/management/commands/replacerelations.py

@@ -0,0 +1,73 @@
+# Patchwork - automated patch tracking system
+# Copyright (C) 2020 Rohit Sarkar <rohitsarkar5398@gmail.com>
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+import logging
+import os
+import sys
+
+from django.db import transaction
+from django.core.management.base import BaseCommand
+
+from patchwork.models import Patch
+from patchwork.models import PatchRelation
+
+logger = logging.getLogger(__name__)
+
+
+class Command(BaseCommand):
+    help = ('Parse a relations file generated by PaStA and replace existing'
+            'relations with the ones parsed')
+
+    def add_arguments(self, parser):
+        parser.add_argument(
+            'infile',
+            help='input relations filename')
+
+    def handle(self, *args, **options):
+        verbosity = int(options['verbosity'])
+        if not verbosity:
+            level = logging.CRITICAL
+        elif verbosity == 1:
+            level = logging.ERROR
+        elif verbosity == 2:
+            level = logging.INFO
+        else:
+            level = logging.DEBUG
+
+        logger.setLevel(level)
+
+        path = args and args[0] or options['infile']
+        if not os.path.exists(path):
+            logger.error('Invalid path: %s', path)
+            sys.exit(1)
+
+        with open(path, 'r') as f:
+            lines = f.readlines()
+
+        # filter out trailing empty lines
+        while len(lines) and not lines[-1]:
+            lines.pop()
+
+        relations = [line.split(' ') for line in lines]
+
+        with transaction.atomic():
+            PatchRelation.objects.all().delete()
+            count = len(relations)
+            ingested = 0
+            logger.info('Parsing %d relations' % count)
+            for i, patch_ids in enumerate(relations):
+                related_patches = Patch.objects.filter(id__in=patch_ids)
+
+                if len(related_patches) > 1:
+                    relation = PatchRelation()
+                    relation.save()
+                    related_patches.update(related=relation)
+                    ingested += 1
+
+                if i % 10 == 0:
+                    self.stdout.write('%06d/%06d\r' % (i, count), ending='')
+                    self.stdout.flush()
+
+            self.stdout.write('Ingested %d relations' % ingested)

patchwork/tests/test_management.py

@@ -5,6 +5,7 @@
 
 import os
 import sys
+import tempfile
 from io import StringIO
 
 from django.core.management import call_command
@@ -124,3 +125,47 @@ def test_invalid_mbox(self):
 
         self.assertIn('Processed 1 messages -->', out.getvalue())
         self.assertIn('  1 dropped', out.getvalue())
+
+
+class ReplacerelationsTest(TestCase):
+
+    def test_invalid_path(self):
+        out = StringIO()
+        with self.assertRaises(SystemExit) as exc:
+            call_command('replacerelations', 'xyz123random', '-v 0',
+                         stdout=out)
+        self.assertEqual(exc.exception.code, 1)
+
+    def test_valid_relations(self):
+        test_submitter = utils.create_person()
+        utils.create_patches(8, submitter=test_submitter)
+        patch_ids = (models.Patch.objects
+                     .filter(submitter=test_submitter)
+                     .values_list('id', flat=True))
+
+        with tempfile.NamedTemporaryFile(delete=False,
+                                         mode='w+') as f1:
+            for i in range(0, len(patch_ids), 3):
+                # we write out the patch IDs this way so that we can
+                # have a mix of 3-patch and 2-patch lines without special
+                # casing the format string.
+                f1.write('%s\n' % ' '.join(map(str, patch_ids[i:(i + 3)])))
+
+        out = StringIO()
+        call_command('replacerelations', f1.name, stdout=out)
+        self.assertEqual(models.PatchRelation.objects.count(), 3)
+        os.unlink(f1.name)
+
+        patch_ids_with_missing = (
+            list(patch_ids) +
+            [i for i in range(max(patch_ids), max(patch_ids) + 3)]
+        )
+        with tempfile.NamedTemporaryFile(delete=False,
+                                         mode='w+') as f2:
+            for i in range(0, len(patch_ids_with_missing), 3):
+                f2.write('%s\n' % ' '.join(
+                    map(str, patch_ids_with_missing[i:(i + 3)])))
+
+        call_command('replacerelations', f2.name, stdout=out)
+        self.assertEqual(models.PatchRelation.objects.count(), 3)
+        os.unlink(f2.name)