--- /dev/null
+# -*- coding: utf-8 -*-
+#
+# This file is part of FNP-Redakcja, licensed under GNU Affero GPLv3 or later.
+# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
+#
+from datetime import datetime
+import os.path
+
+from django.contrib.auth.models import User
+from django.core.files.base import ContentFile
+from django.db import models, transaction
+from django.db.models.base import ModelBase
+from django.utils.translation import string_concat, ugettext_lazy as _
+from mercurial import simplemerge
+
+from django.conf import settings
+from dvcs.signals import post_commit, post_publishable
+from dvcs.storage import GzipFileSystemStorage
+
+
+class Tag(models.Model):
+ """A tag (e.g. document stage) which can be applied to a Change."""
+ name = models.CharField(_('name'), max_length=64)
+ slug = models.SlugField(_('slug'), unique=True, max_length=64, null=True, blank=True)
+ ordering = models.IntegerField(_('ordering'))
+
+ _object_cache = {}
+
+ class Meta:
+ abstract = True
+ ordering = ['ordering']
+
+ def __unicode__(self):
+ return self.name
+
+ @classmethod
+ def get(cls, slug):
+ if slug in cls._object_cache:
+ return cls._object_cache[slug]
+ else:
+ obj = cls.objects.get(slug=slug)
+ cls._object_cache[slug] = obj
+ return obj
+
+ @staticmethod
+ def listener_changed(sender, instance, **kwargs):
+ sender._object_cache = {}
+
+ def get_next(self):
+ """
+ Returns the next tag - stage to work on.
+ Returns None for the last stage.
+ """
+ try:
+ return type(self).objects.filter(ordering__gt=self.ordering)[0]
+ except IndexError:
+ return None
+
+models.signals.pre_save.connect(Tag.listener_changed, sender=Tag)
+
+
+def data_upload_to(instance, filename):
+ return "%d/%d" % (instance.tree.pk, instance.pk)
+
+
+class Change(models.Model):
+ """
+ Single document change related to previous change. The "parent"
+ argument points to the version against which this change has been
+ recorded. Initial text will have a null parent.
+
+ Data file contains a gzipped text of the document.
+ """
+ author = models.ForeignKey(User, null=True, blank=True, verbose_name=_('author'))
+ author_name = models.CharField(
+ _('author name'), max_length=128, null=True, blank=True, help_text=_("Used if author is not set."))
+ author_email = models.CharField(
+ _('author email'), max_length=128, null=True, blank=True, help_text=_("Used if author is not set."))
+ revision = models.IntegerField(_('revision'), db_index=True)
+
+ parent = models.ForeignKey(
+ 'self', null=True, blank=True, default=None, verbose_name=_('parent'), related_name="children")
+
+ merge_parent = models.ForeignKey(
+ 'self', null=True, blank=True, default=None, verbose_name=_('merge parent'), related_name="merge_children")
+
+ description = models.TextField(_('description'), blank=True, default='')
+ created_at = models.DateTimeField(editable=False, db_index=True, default=datetime.now)
+ publishable = models.BooleanField(_('publishable'), default=False)
+
+ class Meta:
+ abstract = True
+ ordering = ('created_at',)
+ unique_together = ['tree', 'revision']
+
+ def __unicode__(self):
+ return u"Id: %r, Tree %r, Parent %r, Data: %s" % (self.id, self.tree_id, self.parent_id, self.data)
+
+ def author_str(self):
+ if self.author:
+ return "%s %s <%s>" % (
+ self.author.first_name,
+ self.author.last_name,
+ self.author.email)
+ else:
+ return "%s <%s>" % (
+ self.author_name,
+ self.author_email
+ )
+
+ def save(self, *args, **kwargs):
+ """
+ take the next available revision number if none yet
+ """
+ if self.revision is None:
+ tree_rev = self.tree.revision()
+ if tree_rev is None:
+ self.revision = 1
+ else:
+ self.revision = tree_rev + 1
+ return super(Change, self).save(*args, **kwargs)
+
+ def materialize(self):
+ f = self.data.storage.open(self.data)
+ text = f.read()
+ f.close()
+ return unicode(text, 'utf-8')
+
+ def merge_with(self, other, author=None,
+ author_name=None, author_email=None,
+ description=u"Automatic merge."):
+ """Performs an automatic merge after straying commits."""
+ assert self.tree_id == other.tree_id # same tree
+ if other.parent_id == self.pk:
+ # immediate child - fast forward
+ return other
+
+ local = self.materialize().encode('utf-8')
+ base = other.parent.materialize().encode('utf-8')
+ remote = other.materialize().encode('utf-8')
+
+ merge = simplemerge.Merge3Text(base, local, remote)
+ result = ''.join(merge.merge_lines())
+ merge_node = self.children.create(
+ merge_parent=other, tree=self.tree,
+ author=author,
+ author_name=author_name,
+ author_email=author_email,
+ description=description)
+ merge_node.data.save('', ContentFile(result))
+ return merge_node
+
+ def revert(self, **kwargs):
+ """ commit this version of a doc as new head """
+ self.tree.commit(text=self.materialize(), **kwargs)
+
+ def set_publishable(self, publishable):
+ self.publishable = publishable
+ self.save()
+ post_publishable.send(sender=self, publishable=publishable)
+
+
+def create_tag_model(model):
+ name = model.__name__ + 'Tag'
+
+ class Meta(Tag.Meta):
+ app_label = model._meta.app_label
+ verbose_name = string_concat(
+ _("tag"), " ", _("for:"), " ", model._meta.verbose_name)
+ verbose_name_plural = string_concat(
+ _("tags"), " ", _("for:"), " ", model._meta.verbose_name)
+
+ attrs = {
+ '__module__': model.__module__,
+ 'Meta': Meta,
+ }
+ return type(name, (Tag,), attrs)
+
+
+def create_change_model(model):
+ name = model.__name__ + 'Change'
+ repo = GzipFileSystemStorage(location=model.REPO_PATH)
+
+ class Meta(Change.Meta):
+ app_label = model._meta.app_label
+ verbose_name = string_concat(
+ _("change"), " ", _("for:"), " ", model._meta.verbose_name)
+ verbose_name_plural = string_concat(
+ _("changes"), " ", _("for:"), " ", model._meta.verbose_name)
+
+ attrs = {
+ '__module__': model.__module__,
+ 'tree': models.ForeignKey(model, related_name='change_set', verbose_name=_('document')),
+ 'tags': models.ManyToManyField(model.tag_model, verbose_name=_('tags'), related_name='change_set'),
+ 'data': models.FileField(_('data'), upload_to=data_upload_to, storage=repo),
+ 'Meta': Meta,
+ }
+ return type(name, (Change,), attrs)
+
+
+class DocumentMeta(ModelBase):
+ """Metaclass for Document models."""
+ def __new__(cls, name, bases, attrs):
+
+ model = super(DocumentMeta, cls).__new__(cls, name, bases, attrs)
+ if not model._meta.abstract:
+ # create a real Tag object and `stage' fk
+ model.tag_model = create_tag_model(model)
+ models.ForeignKey(model.tag_model, verbose_name=_('stage'),
+ null=True, blank=True).contribute_to_class(model, 'stage')
+
+ # create real Change model and `head' fk
+ model.change_model = create_change_model(model)
+
+ models.ForeignKey(
+ model.change_model, null=True, blank=True, default=None,
+ verbose_name=_('head'), help_text=_("This document's current head."),
+ editable=False).contribute_to_class(model, 'head')
+
+ models.ForeignKey(
+ User, null=True, blank=True, editable=False,
+ verbose_name=_('creator'), related_name="created_%s" % name.lower()
+ ).contribute_to_class(model, 'creator')
+
+ return model
+
+
+class Document(models.Model):
+ """File in repository. Subclass it to use version control in your app."""
+
+ __metaclass__ = DocumentMeta
+
+ # default repository path
+ REPO_PATH = os.path.join(settings.MEDIA_ROOT, 'dvcs')
+
+ user = models.ForeignKey(User, null=True, blank=True, verbose_name=_('user'), help_text=_('Work assignment.'))
+
+ class Meta:
+ abstract = True
+
+ def __unicode__(self):
+ return u"{0}, HEAD: {1}".format(self.id, self.head_id)
+
+ def materialize(self, change=None):
+ if self.head is None:
+ return u''
+ if change is None:
+ change = self.head
+ elif not isinstance(change, Change):
+ change = self.change_set.get(pk=change)
+ return change.materialize()
+
+ def commit(self, text, author=None, author_name=None, author_email=None, publishable=False, **kwargs):
+ """Commits a new revision.
+
+ This will automatically merge the commit into the main branch,
+ if parent is not document's head.
+
+ :param unicode text: new version of the document
+ :param parent: parent revision (head, if not specified)
+ :type parent: Change or None
+ :param User author: the commiter
+ :param unicode author_name: commiter name (if ``author`` not specified)
+ :param unicode author_email: commiter e-mail (if ``author`` not specified)
+ :param Tag[] tags: list of tags to apply to the new commit
+ :param bool publishable: set new commit as ready to publish
+ :returns: new head
+ """
+ if 'parent' not in kwargs:
+ parent = self.head
+ else:
+ parent = kwargs['parent']
+ if parent is not None and not isinstance(parent, Change):
+ parent = self.change_set.objects.get(pk=kwargs['parent'])
+
+ tags = kwargs.get('tags', [])
+ if tags:
+ # set stage to next tag after the commited one
+ self.stage = max(tags, key=lambda t: t.ordering).get_next()
+
+ change = self.change_set.create(
+ author=author, author_name=author_name, author_email=author_email,
+ description=kwargs.get('description', ''), publishable=publishable, parent=parent)
+
+ change.tags = tags
+ change.data.save('', ContentFile(text.encode('utf-8')))
+ change.save()
+
+ if self.head:
+ # merge new change as new head
+ self.head = self.head.merge_with(change, author=author,
+ author_name=author_name,
+ author_email=author_email)
+ else:
+ self.head = change
+ self.save()
+
+ post_commit.send(sender=self.head)
+
+ return self.head
+
+ def history(self):
+ return self.change_set.all().order_by('revision')
+
+ def revision(self):
+ rev = self.change_set.aggregate(
+ models.Max('revision'))['revision__max']
+ return rev
+
+ def at_revision(self, rev):
+ """Returns a Change with given revision number."""
+ return self.change_set.get(revision=rev)
+
+ def publishable(self):
+ changes = self.history().filter(publishable=True)
+ if changes.exists():
+ return changes.order_by('-revision')[0]
+ else:
+ return None
+
+ @transaction.atomic
+ def prepend_history(self, other):
+ """Takes over the the other document's history and prepends to own."""
+
+ assert self != other
+ other_revs = other.change_set.all().count()
+ # workaround for a non-atomic UPDATE in SQLITE
+ self.change_set.all().update(revision=0-models.F('revision'))
+ self.change_set.all().update(revision=other_revs - models.F('revision'))
+ other.change_set.all().update(tree=self)
+ assert not other.change_set.exists()
+ other.delete()