models.py 21 KB
Newer Older
Jeremy Kerr's avatar
Jeremy Kerr committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
# Patchwork - automated patch tracking system
# Copyright (C) 2008 Jeremy Kerr <jk@ozlabs.org>
#
# This file is part of the Patchwork package.
#
# Patchwork is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# Patchwork is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Patchwork; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

from django.db import models
21
from django.db.models import Q
22
import django.dispatch
Jeremy Kerr's avatar
Jeremy Kerr committed
23 24 25
from django.contrib.auth.models import User
from django.core.urlresolvers import reverse
from django.contrib.sites.models import Site
26
from django.conf import settings
Jeremy Kerr's avatar
Jeremy Kerr committed
27 28
from django.utils.functional import cached_property
from patchwork.parser import hash_patch, extract_tags
Jeremy Kerr's avatar
Jeremy Kerr committed
29 30 31 32

import re
import datetime, time
import random
Jeremy Kerr's avatar
Jeremy Kerr committed
33
from collections import Counter, OrderedDict
34

Jeremy Kerr's avatar
Jeremy Kerr committed
35 36
class Person(models.Model):
    email = models.CharField(max_length=255, unique = True)
37
    name = models.CharField(max_length=255, null = True, blank = True)
38 39
    user = models.ForeignKey(User, null = True, blank = True,
            on_delete = models.SET_NULL)
Jeremy Kerr's avatar
Jeremy Kerr committed
40

41
    def __unicode__(self):
Jeremy Kerr's avatar
Jeremy Kerr committed
42
        if self.name:
43
            return u'%s <%s>' % (self.name, self.email)
Jeremy Kerr's avatar
Jeremy Kerr committed
44 45 46 47
        else:
            return self.email

    def link_to_user(self, user):
48
        self.name = user.profile.name()
Jeremy Kerr's avatar
Jeremy Kerr committed
49 50 51 52 53 54 55 56 57 58
        self.user = user

    class Meta:
        verbose_name_plural = 'People'

class Project(models.Model):
    linkname = models.CharField(max_length=255, unique=True)
    name = models.CharField(max_length=255, unique=True)
    listid = models.CharField(max_length=255, unique=True)
    listemail = models.CharField(max_length=200)
Simo Sorce's avatar
Simo Sorce committed
59 60 61
    web_url = models.CharField(max_length=2000, blank=True)
    scm_url = models.CharField(max_length=2000, blank=True)
    webscm_url = models.CharField(max_length=2000, blank=True)
Jeremy Kerr's avatar
Jeremy Kerr committed
62
    send_notifications = models.BooleanField(default=False)
Jeremy Kerr's avatar
Jeremy Kerr committed
63
    use_tags = models.BooleanField(default=True)
64
    git_send_email_only = models.BooleanField(default=False)
Jeremy Kerr's avatar
Jeremy Kerr committed
65

66
    def __unicode__(self):
Jeremy Kerr's avatar
Jeremy Kerr committed
67 68
        return self.name

69 70 71
    def is_editable(self, user):
        if not user.is_authenticated():
            return False
72
        return self in user.profile.maintainer_projects.all()
73

Jeremy Kerr's avatar
Jeremy Kerr committed
74 75 76 77 78 79
    @cached_property
    def tags(self):
        if not self.use_tags:
            return []
        return list(Tag.objects.all())

80 81 82
    class Meta:
        ordering = ['linkname']

83 84 85 86 87
def user_name(user):
    if user.first_name or user.last_name:
        names = filter(bool, [user.first_name, user.last_name])
        return u' '.join(names)
    return user.username
88

Jeremy Kerr's avatar
Jeremy Kerr committed
89
class UserProfile(models.Model):
90
    user = models.OneToOneField(User, unique = True, related_name='profile')
91
    primary_project = models.ForeignKey(Project, null = True, blank = True)
Jeremy Kerr's avatar
Jeremy Kerr committed
92 93 94 95 96 97 98 99 100 101
    maintainer_projects = models.ManyToManyField(Project,
            related_name = 'maintainer_project')
    send_email = models.BooleanField(default = False,
            help_text = 'Selecting this option allows patchwork to send ' +
                'email on your behalf')
    patches_per_page = models.PositiveIntegerField(default = 100,
            null = False, blank = False,
            help_text = 'Number of patches to display per page')

    def name(self):
102
        return user_name(self.user)
Jeremy Kerr's avatar
Jeremy Kerr committed
103 104 105

    def contributor_projects(self):
        submitters = Person.objects.filter(user = self.user)
106 107 108 109
        return Project.objects.filter(id__in =
                                        Patch.objects.filter(
                                            submitter__in = submitters)
                                        .values('project_id').query)
Jeremy Kerr's avatar
Jeremy Kerr committed
110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126

    def sync_person(self):
        pass

    def n_todo_patches(self):
        return self.todo_patches().count()

    def todo_patches(self, project = None):

        # filter on project, if necessary
        if project:
            qs = Patch.objects.filter(project = project)
        else:
            qs = Patch.objects

        qs = qs.filter(archived = False) \
             .filter(delegate = self.user) \
127 128
             .filter(state__in =
                     State.objects.filter(action_required = True)
Jeremy Kerr's avatar
Jeremy Kerr committed
129 130 131
                         .values('pk').query)
        return qs

132
    def __unicode__(self):
Jeremy Kerr's avatar
Jeremy Kerr committed
133 134
        return self.name()

135 136
def _user_saved_callback(sender, created, instance, **kwargs):
    try:
137
        profile = instance.profile
138 139
    except UserProfile.DoesNotExist:
        profile = UserProfile(user = instance)
140 141
    profile.save()

142
models.signals.post_save.connect(_user_saved_callback, sender = User)
143

Jeremy Kerr's avatar
Jeremy Kerr committed
144 145 146 147 148
class State(models.Model):
    name = models.CharField(max_length = 100)
    ordering = models.IntegerField(unique = True)
    action_required = models.BooleanField(default = True)

149
    def __unicode__(self):
Jeremy Kerr's avatar
Jeremy Kerr committed
150 151 152 153 154
        return self.name

    class Meta:
        ordering = ['ordering']

Jeremy Kerr's avatar
Jeremy Kerr committed
155
class HashField(models.CharField):
Jeremy Kerr's avatar
Jeremy Kerr committed
156 157 158 159
    __metaclass__ = models.SubfieldBase

    def __init__(self, algorithm = 'sha1', *args, **kwargs):
        self.algorithm = algorithm
Nate Case's avatar
Nate Case committed
160 161
        try:
            import hashlib
Jeremy Kerr's avatar
Jeremy Kerr committed
162 163 164
            def _construct(string = ''):
                return hashlib.new(self.algorithm, string)
            self.construct = _construct
165
            self.n_bytes = len(hashlib.new(self.algorithm).hexdigest())
Nate Case's avatar
Nate Case committed
166
        except ImportError:
Jeremy Kerr's avatar
Jeremy Kerr committed
167 168 169
            modules = { 'sha1': 'sha', 'md5': 'md5'}

            if algorithm not in modules.keys():
Nate Case's avatar
Nate Case committed
170
                raise NameError("Unknown algorithm '%s'" % algorithm)
Jeremy Kerr's avatar
Jeremy Kerr committed
171 172 173 174

            self.construct = __import__(modules[algorithm]).new

        self.n_bytes = len(self.construct().hexdigest())
Jeremy Kerr's avatar
Jeremy Kerr committed
175

176
        kwargs['max_length'] = self.n_bytes
Jeremy Kerr's avatar
Jeremy Kerr committed
177 178
        super(HashField, self).__init__(*args, **kwargs)

179
    def db_type(self, connection=None):
180
        return 'char(%d)' % self.n_bytes
Jeremy Kerr's avatar
Jeremy Kerr committed
181

Jeremy Kerr's avatar
Jeremy Kerr committed
182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209
class Tag(models.Model):
    name = models.CharField(max_length=20)
    pattern = models.CharField(max_length=50,
                help_text='A simple regex to match the tag in the content of '
                    'a message. Will be used with MULTILINE and IGNORECASE '
                    'flags. eg. ^Acked-by:')
    abbrev = models.CharField(max_length=2, unique=True,
                help_text='Short (one-or-two letter) abbreviation for the tag, '
                    'used in table column headers')

    def __unicode__(self):
        return self.name

    @property
    def attr_name(self):
        return 'tag_%d_count' % self.id

    class Meta:
        ordering = ['abbrev']

class PatchTag(models.Model):
    patch = models.ForeignKey('Patch')
    tag = models.ForeignKey('Tag')
    count = models.IntegerField(default=1)

    class Meta:
        unique_together = [('patch', 'tag')]

210 211 212
def get_default_initial_patch_state():
    return State.objects.get(ordering=0)

Jeremy Kerr's avatar
Jeremy Kerr committed
213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243
class PatchQuerySet(models.query.QuerySet):

    def with_tag_counts(self, project):
        if not project.use_tags:
            return self

        # We need the project's use_tags field loaded for Project.tags().
        # Using prefetch_related means we'll share the one instance of
        # Project, and share the project.tags cache between all patch.project
        # references.
        qs = self.prefetch_related('project')
        select = OrderedDict()
        select_params = []
        for tag in project.tags:
            select[tag.attr_name] = ("coalesce("
                "(SELECT count FROM patchwork_patchtag "
                "WHERE patchwork_patchtag.patch_id=patchwork_patch.id "
                    "AND patchwork_patchtag.tag_id=%s), 0)")
            select_params.append(tag.id)

        return qs.extra(select=select, select_params=select_params)

class PatchManager(models.Manager):
    use_for_related_fields = True

    def get_queryset(self):
        return PatchQuerySet(self.model, using=self.db)

    def with_tag_counts(self, project):
        return self.get_queryset().with_tag_counts(project)

Jeremy Kerr's avatar
Jeremy Kerr committed
244 245
class Patch(models.Model):
    project = models.ForeignKey(Project)
246
    msgid = models.CharField(max_length=255)
Jeremy Kerr's avatar
Jeremy Kerr committed
247 248 249 250
    name = models.CharField(max_length=255)
    date = models.DateTimeField(default=datetime.datetime.now)
    submitter = models.ForeignKey(Person)
    delegate = models.ForeignKey(User, blank = True, null = True)
251
    state = models.ForeignKey(State, null=True)
Jeremy Kerr's avatar
Jeremy Kerr committed
252 253
    archived = models.BooleanField(default = False)
    headers = models.TextField(blank = True)
254 255
    content = models.TextField(null = True, blank = True)
    pull_url = models.CharField(max_length=255, null = True, blank = True)
Jeremy Kerr's avatar
Jeremy Kerr committed
256
    commit_ref = models.CharField(max_length=255, null = True, blank = True)
257
    hash = HashField(null = True, blank = True)
Jeremy Kerr's avatar
Jeremy Kerr committed
258 259 260
    tags = models.ManyToManyField(Tag, through=PatchTag)

    objects = PatchManager()
Jeremy Kerr's avatar
Jeremy Kerr committed
261

262
    def __unicode__(self):
Jeremy Kerr's avatar
Jeremy Kerr committed
263 264
        return self.name

265 266 267 268 269 270 271 272
    def commit_message(self):
        """Retrieves the commit message"""
        return Comment.objects.filter(patch=self, msgid=self.msgid)

    def answers(self):
        """Retrieves the answers (ie all comments but the commit message)"""
        return Comment.objects.filter(Q(patch=self) & ~Q(msgid=self.msgid))

Jeremy Kerr's avatar
Jeremy Kerr committed
273
    def comments(self):
274 275
        """Retrieves all comments of this patch ie. the commit message and the
           answers"""
276
        return Comment.objects.filter(patch = self)
Jeremy Kerr's avatar
Jeremy Kerr committed
277

Jeremy Kerr's avatar
Jeremy Kerr committed
278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295
    def _set_tag(self, tag, count):
        if count == 0:
            self.patchtag_set.filter(tag=tag).delete()
            return
        (patchtag, _) = PatchTag.objects.get_or_create(patch=self, tag=tag)
        if patchtag.count != count:
            patchtag.count = count
            patchtag.save()

    def refresh_tag_counts(self):
        tags = self.project.tags
        counter = Counter()
        for comment in self.comment_set.all():
            counter = counter + extract_tags(comment.content, tags)

        for tag in tags:
            self._set_tag(tag, counter[tag])

Jeremy Kerr's avatar
Jeremy Kerr committed
296
    def save(self):
297 298
        if not hasattr(self, 'state') or not self.state:
            self.state = get_default_initial_patch_state()
Jeremy Kerr's avatar
Jeremy Kerr committed
299

300
        if self.hash is None and self.content is not None:
Jeremy Kerr's avatar
Jeremy Kerr committed
301
            self.hash = hash_patch(self.content).hexdigest()
Jeremy Kerr's avatar
Jeremy Kerr committed
302

Jeremy Kerr's avatar
Jeremy Kerr committed
303 304 305 306 307 308 309 310 311
        super(Patch, self).save()

    def is_editable(self, user):
        if not user.is_authenticated():
            return False

        if self.submitter.user == user or self.delegate == user:
            return True

312
        return self.project.is_editable(user)
Jeremy Kerr's avatar
Jeremy Kerr committed
313 314 315 316 317 318 319 320 321 322 323 324 325

    def filename(self):
        fname_re = re.compile('[^-_A-Za-z0-9\.]+')
        str = fname_re.sub('-', self.name)
        return str.strip('-') + '.patch'

    @models.permalink
    def get_absolute_url(self):
        return ('patchwork.views.patch.patch', (), {'patch_id': self.id})

    class Meta:
        verbose_name_plural = 'Patches'
        ordering = ['date']
326
        unique_together = [('msgid', 'project')]
Jeremy Kerr's avatar
Jeremy Kerr committed
327 328 329

class Comment(models.Model):
    patch = models.ForeignKey(Patch)
330
    msgid = models.CharField(max_length=255)
Jeremy Kerr's avatar
Jeremy Kerr committed
331 332 333 334 335
    submitter = models.ForeignKey(Person)
    date = models.DateTimeField(default = datetime.datetime.now)
    headers = models.TextField(blank = True)
    content = models.TextField()

336 337 338
    response_re = re.compile( \
            '^(Tested|Reviewed|Acked|Signed-off|Nacked|Reported)-by: .*$',
            re.M | re.I)
339 340

    def patch_responses(self):
341
        return ''.join([ match.group(0) + '\n' for match in
342 343
                                self.response_re.finditer(self.content)])

Jeremy Kerr's avatar
Jeremy Kerr committed
344 345 346 347 348 349 350 351
    def save(self, *args, **kwargs):
        super(Comment, self).save(*args, **kwargs)
        self.patch.refresh_tag_counts()

    def delete(self, *args, **kwargs):
        super(Comment, self).delete(*args, **kwargs)
        self.patch.refresh_tag_counts()

Jeremy Kerr's avatar
Jeremy Kerr committed
352 353
    class Meta:
        ordering = ['date']
354
        unique_together = [('msgid', 'patch')]
Jeremy Kerr's avatar
Jeremy Kerr committed
355 356 357 358 359

class Bundle(models.Model):
    owner = models.ForeignKey(User)
    project = models.ForeignKey(Project)
    name = models.CharField(max_length = 50, null = False, blank = False)
360
    patches = models.ManyToManyField(Patch, through = 'BundlePatch')
Jeremy Kerr's avatar
Jeremy Kerr committed
361 362 363 364 365
    public = models.BooleanField(default = False)

    def n_patches(self):
        return self.patches.all().count()

Jeremy Kerr's avatar
Jeremy Kerr committed
366
    def ordered_patches(self):
Guilherme Salgado's avatar
Guilherme Salgado committed
367
        return self.patches.order_by('bundlepatch__order')
Jeremy Kerr's avatar
Jeremy Kerr committed
368

369 370
    def append_patch(self, patch):
        # todo: use the aggregate queries in django 1.1
Jeremy Kerr's avatar
Jeremy Kerr committed
371 372 373 374 375 376 377 378 379 380 381
        orders = BundlePatch.objects.filter(bundle = self).order_by('-order') \
                 .values('order')

        if len(orders) > 0:
            max_order = orders[0]['order']
        else:
            max_order = 0

        # see if the patch is already in this bundle
        if BundlePatch.objects.filter(bundle = self, patch = patch).count():
            raise Exception("patch is already in bundle")
382

Jeremy Kerr's avatar
Jeremy Kerr committed
383 384
        bp = BundlePatch.objects.create(bundle = self, patch = patch,
                order = max_order + 1)
385 386
        bp.save()

Jeremy Kerr's avatar
Jeremy Kerr committed
387 388 389 390 391 392 393 394
    class Meta:
        unique_together = [('owner', 'name')]

    def public_url(self):
        if not self.public:
            return None
        site = Site.objects.get_current()
        return 'http://%s%s' % (site.domain,
395
                reverse('patchwork.views.bundle.bundle',
Jeremy Kerr's avatar
Jeremy Kerr committed
396 397 398 399 400
                        kwargs = {
                                'username': self.owner.username,
                                'bundlename': self.name
                        }))

401 402 403 404 405 406 407
    @models.permalink
    def get_absolute_url(self):
        return ('patchwork.views.bundle.bundle', (), {
                                'username': self.owner.username,
                                'bundlename': self.name,
                            })

408 409 410 411 412 413
class BundlePatch(models.Model):
    patch = models.ForeignKey(Patch)
    bundle = models.ForeignKey(Bundle)
    order = models.IntegerField()

    class Meta:
Jeremy Kerr's avatar
Jeremy Kerr committed
414 415
        unique_together = [('bundle', 'patch')]
        ordering = ['order']
416

Damien Lespiau's avatar
Damien Lespiau committed
417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460
SERIES_DEFAULT_NAME = "Series without cover letter"

# This Model represents the "top level" Series, an object that doesn't change
# with the various versions of patches sent to the mailing list.
class Series(models.Model):
    project = models.ForeignKey(Project)
    name = models.CharField(max_length=200, default=SERIES_DEFAULT_NAME)
    submitter = models.ForeignKey(Person, related_name='submitters')
    reviewer = models.ForeignKey(User, related_name='reviewers', null=True,
                                 blank=True)
    submitted = models.DateTimeField(default=datetime.datetime.now)
    last_updated = models.DateTimeField(auto_now=True)
    # Caches the latest version so we can display it without looking at the max
    # of all SeriesRevision.version
    version = models.IntegerField(default=1)
    # This is the number of patches of the latest version.
    n_patches = models.IntegerField(default=0)

    def __unicode__(self):
        return self.name

    def revisions(self):
        return SeriesRevision.objects.filter(series=self)

    def latest_revision(self):
        return self.revisions().reverse()[0]

    def get_absolute_url(self):
        return reverse('series', kwargs={ 'series': self.pk })

    def dump(self):
        print('')
        print('===')
        print('Series: %s' % self)
        print('    version %d' % self.version)
        for rev in self.revisions():
            print('    rev %d:' % rev.version)
            i = 1
            for patch in rev.ordered_patches():
                print('        patch %d:' % i)
                print('            subject: %s' % patch.name)
                print('            msgid  : %s' % patch.msgid)
                i += 1

461 462 463 464
# Signal one can listen to to know when a revision is complete (ie. has all of
# its patches)
series_revision_complete = django.dispatch.Signal(providing_args=["revision"])

Damien Lespiau's avatar
Damien Lespiau committed
465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490
# A 'revision' of a series. Resending a new version of a patch or a full new
# iteration of a series will create a new revision.
class SeriesRevision(models.Model):
    series = models.ForeignKey(Series)
    version = models.IntegerField(default=1)
    root_msgid = models.CharField(max_length=255)
    cover_letter = models.TextField(null = True, blank = True)
    patches = models.ManyToManyField(Patch, through = 'SeriesRevisionPatch')

    class Meta:
        unique_together = [('series', 'version')]
        ordering = ['version']

    def ordered_patches(self):
        return self.patches.order_by('seriesrevisionpatch__order')

    def add_patch(self, patch, order):
        # see if the patch is already in this revision
        if SeriesRevisionPatch.objects.filter(revision=self,
                                              patch=patch).count():
            raise Exception("patch is already in revision")

        sp = SeriesRevisionPatch.objects.create(revision=self, patch=patch,
                                                order=order)
        sp.save()

491 492 493 494
        revision_complete = self.patches.count() == self.series.n_patches
        if revision_complete:
            series_revision_complete.send(sender=self.__class__, revision=self)

495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521
    def duplicate_meta(self):
        new = SeriesRevision.objects.get(pk=self.pk)
        new.pk = None
        new.cover_letter = None
        new.version = self.version + 1
        new.save()

        series = new.series
        series.version = new.version
        series.save()

        return new

    def duplicate(self, exclude_patches=()):
        """Create a new revision based on 'self', incrementing the version
           and populating the new revision with all 'self' patches.
           exclude_patch (a list of 'order's) can be used to exclude
           patches from the operation"""
        new = self.duplicate_meta()
        order = 0
        for p in self.ordered_patches():
            order += 1
            if order in exclude_patches:
                continue
            new.add_patch(p, order)
        return new

Damien Lespiau's avatar
Damien Lespiau committed
522 523 524 525 526 527 528 529 530 531 532 533 534 535 536
    def __unicode__(self):
        if hasattr(self, 'series'):
            return self.series.name + " (rev " + str(self.version) + ")"
        else:
            return "New revision" + " (rev " + str(self.version) + ")"

class SeriesRevisionPatch(models.Model):
    patch = models.ForeignKey(Patch)
    revision = models.ForeignKey(SeriesRevision)
    order = models.IntegerField()

    class Meta:
        unique_together = [('revision', 'patch'), ('revision', 'order')]
        ordering = ['order']

537
class EmailConfirmation(models.Model):
538
    validity = datetime.timedelta(days = settings.CONFIRMATION_VALIDITY_DAYS)
539 540
    type = models.CharField(max_length = 20, choices = [
                                ('userperson', 'User-Person association'),
541
                                ('registration', 'Registration'),
Jeremy Kerr's avatar
Jeremy Kerr committed
542
                                ('optout', 'Email opt-out'),
543
                            ])
544
    email = models.CharField(max_length = 200)
545
    user = models.ForeignKey(User, null = True)
546
    key = HashField()
547
    date = models.DateTimeField(default = datetime.datetime.now)
548 549
    active = models.BooleanField(default = True)

550
    def deactivate(self):
551
        self.active = False
552
        self.save()
553

554 555 556
    def is_valid(self):
        return self.date + self.validity > datetime.datetime.now()

557 558 559 560 561
    def save(self):
        max = 1 << 32
        if self.key == '':
            str = '%s%s%d' % (self.user, self.email, random.randint(0, max))
            self.key = self._meta.get_field('key').construct(str).hexdigest()
562
        super(EmailConfirmation, self).save()
563

Jeremy Kerr's avatar
Jeremy Kerr committed
564 565
class EmailOptout(models.Model):
    email = models.CharField(max_length = 200, primary_key = True)
566

Jeremy Kerr's avatar
Jeremy Kerr committed
567 568
    def __unicode__(self):
        return self.email
569

Jeremy Kerr's avatar
Jeremy Kerr committed
570 571 572 573 574
    @classmethod
    def is_optout(cls, email):
        email = email.lower().strip()
        return cls.objects.filter(email = email).count() > 0

575
class PatchChangeNotification(models.Model):
576
    patch = models.OneToOneField(Patch, primary_key = True)
577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616
    last_modified = models.DateTimeField(default = datetime.datetime.now)
    orig_state = models.ForeignKey(State)

def _patch_change_callback(sender, instance, **kwargs):
    # we only want notification of modified patches
    if instance.pk is None:
        return

    if instance.project is None or not instance.project.send_notifications:
        return

    try:
        orig_patch = Patch.objects.get(pk = instance.pk)
    except Patch.DoesNotExist:
        return

    # If there's no interesting changes, abort without creating the
    # notification
    if orig_patch.state == instance.state:
        return

    notification = None
    try:
        notification = PatchChangeNotification.objects.get(patch = instance)
    except PatchChangeNotification.DoesNotExist:
        pass

    if notification is None:
        notification = PatchChangeNotification(patch = instance,
                                               orig_state = orig_patch.state)

    elif notification.orig_state == instance.state:
        # If we're back at the original state, there is no need to notify
        notification.delete()
        return

    notification.last_modified = datetime.datetime.now()
    notification.save()

models.signals.pre_save.connect(_patch_change_callback, sender = Patch)