tutorial and help texts for tags in new resource form

[redakcja.git] / apps / dvcs / models.py

diff --git a/apps/dvcs/models.py b/apps/dvcs/models.py
index 1c30387..6ecb97c 100644 (file)
--- a/apps/dvcs/models.py
+++ b/apps/dvcs/models.py
@@ -1,179 +1,261 @@
+# -*- coding: utf-8 -*-
+#
+# This file is part of MIL/PEER, licensed under GNU Affero GPLv3 or later.
+# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
+#
+from __future__ import unicode_literals, print_function
+
+from datetime import datetime
+import os
+import re
+from subprocess import PIPE, Popen
+from tempfile import NamedTemporaryFile
+
+from django.conf import settings
+from django.core.files.base import ContentFile

 from django.db import models
 from django.db import models

-from django.contrib.auth.models import User
+from django.utils.encoding import python_2_unicode_compatible

 from django.utils.translation import ugettext_lazy as _
 from django.utils.translation import ugettext_lazy as _

-from mercurial import mdiff, simplemerge
-import pickle

 
 

-class Change(models.Model):
+from dvcs.signals import post_commit, post_merge
+from dvcs.storage import GzipFileSystemStorage
+
+# default repository path; make a setting for it
+REPO_PATH = os.path.join(settings.MEDIA_ROOT, 'dvcs')
+repo = GzipFileSystemStorage(location=REPO_PATH)
+
+
+@python_2_unicode_compatible
+class Revision(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 contains a pickled diff needed to reproduce the initial document.
+    A document revision. The "parent"
+    argument points to the version against which this change has been 
+    recorded. Initial text will have a null parent.
+
+    Gzipped text of the document is stored in a file.

     """
     """

-    author = models.ForeignKey(User, null=True, blank=True)
-    patch = models.TextField(blank=True)
-    tree = models.ForeignKey('Document')
+    author = models.ForeignKey(settings.AUTH_USER_MODEL, 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."))
+    # Any other author data?
+    # How do we identify an author?

 
 

-    parent = models.ForeignKey('self',
-                        null=True, blank=True, default=None,
-                        related_name="children")
+    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,
-                        related_name="merge_children")
+    merge_parent = models.ForeignKey(
+        'self', null=True, blank=True, default=None, verbose_name=_('merge parent'), related_name="merge_children")

 
 

-    description = models.TextField(blank=True, default='')
-    created_at = models.DateTimeField(auto_now_add=True)
+    description = models.TextField(_('description'), blank=True, default='')
+    created_at = models.DateTimeField(editable=False, db_index=True, default=datetime.now)

 
     class Meta:
         ordering = ('created_at',)
 
     class Meta:
         ordering = ('created_at',)

+        verbose_name = _("revision")
+        verbose_name_plural = _("revisions")
+
+    def __str__(self):
+        return "Id: %r, Parent %r, Data: %s" % (self.id, self.parent_id, self.get_text_path())

 
 

-    def __unicode__(self):
-        return u"Id: %r, Tree %r, Parent %r, Patch '''\n%s'''" % (self.id, self.tree_id, self.parent_id, self.patch)
+    def get_text_path(self):
+        if self.pk:
+            return re.sub(r'([0-9a-f]{2})([^.])', r'\1/\2', '%x.gz' % self.pk)
+        else:
+            return None

 
 

-    @staticmethod
-    def make_patch(src, dst):
-        if isinstance(src, unicode):
-            src = src.encode('utf-8')
-        if isinstance(dst, unicode):
-            dst = dst.encode('utf-8')
-        return pickle.dumps(mdiff.textdiff(src, dst))
+    def save_text(self, content):
+        return repo.save(self.get_text_path(), ContentFile(content.encode('utf-8')))
+
+    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
+                )
+
+    @classmethod
+    def create(cls, text, parent=None, merge_parent=None, author=None, author_name=None, author_email=None,
+               description=''):
+
+        if text:
+            text = text.replace(
+                '<dc:></dc:>', '').replace(
+                '<div class="img">', '<div>')
+
+        revision = cls.objects.create(
+            parent=parent,
+            merge_parent=merge_parent,
+            author=author,
+            author_name=author_name,
+            author_email=author_email,
+            description=description
+        )
+        revision.save_text(text)
+        return revision

 
     def materialize(self):
 
     def materialize(self):

-        # special care for merged nodes
-        if self.parent is None and self.merge_parent is not None:
-            return self.apply_to(self.merge_parent.materialize())
-
-        changes = Change.objects.filter(
-                        ~models.Q(parent=None) | models.Q(merge_parent=None),
-                        tree=self.tree,
-                        created_at__lte=self.created_at).order_by('created_at')
-        text = u''
-        for change in changes:
-            text = change.apply_to(text)
+        f = repo.open(self.get_text_path())
+        text = f.read().decode('utf-8')
+        f.close()
+        if text:
+            text = text.replace(
+                '<dc:></dc:>', '').replace(
+                '<div class="img">', '<div>')

         return text
 
         return text
 

-    def make_child(self, patch, author, description):
-        return self.children.create(patch=patch,
-                        tree=self.tree, author=author,
-                        description=description)
+    def is_descendant_of(self, other):
+        # Naive approach.
+        return (
+            (
+                self.parent is not None and (
+                    self.parent.pk == other.pk or
+                    self.parent.is_descendant_of(other)
+                )
+            ) or (
+                self.merge_parent is not None and (
+                    self.merge_parent.pk == other.pk or
+                    self.merge_parent.is_descendant_of(other)
+                )
+            )
+        )

 
 

-    def make_merge_child(self, patch, author, description):
-        return self.merge_children.create(patch=patch,
-                        tree=self.tree, author=author,
-                        description=description)
+    def get_common_ancestor_with(self, other):
+        # VERY naive approach.
+        if self.pk == other.pk:
+            return self
+        if self.is_descendant_of(other):
+            return other
+        if other.is_descendant_of(self):
+            return self

 
 

-    def apply_to(self, text):
-        return mdiff.patch(text, pickle.loads(self.patch.encode('ascii')))
+        if self.parent is not None:
+            parent_ca = self.parent.get_common_ancestor_with(other)
+        else:
+            parent_ca = None

 
 

-    def merge_with(self, other, author, description=u"Automatic merge."):
-        assert self.tree_id == other.tree_id  # same tree
-        if other.parent_id == self.pk:
-            # immediate child 
-            return other
+        if self.merge_parent is not None:
+            merge_parent_ca = self.merge_parent.get_common_ancestor_with(other)
+        else:
+            return parent_ca

 
 

-        local = self.materialize()
-        base = other.merge_parent.materialize()
-        remote = other.apply_to(base)
+        if parent_ca is None or parent_ca.created_at < merge_parent_ca.created_at:
+            return merge_parent_ca

 
 

-        merge = simplemerge.Merge3Text(base, local, remote)
-        result = ''.join(merge.merge_lines())
-        patch = self.make_patch(local, result)
-        return self.children.create(
-                    patch=patch, merge_parent=other, tree=self.tree,
-                    author=author, description=description)
+        return parent_ca

 
 

-    def revert(self, **kwargs):
-        """ commit this version of a doc as new head """
-        self.tree.commit(text=self.materialize(), **kwargs)
+    def get_ancestors(self):
+        revs = set()
+        if self.parent is not None:
+            revs.add(self.parent)
+            revs.update(self.parent.get_ancestors())
+        if self.merge_parent is not None:
+            revs.add(self.merge_parent)
+            revs.update(self.merge_parent.get_ancestors())
+        return revs

 
 
 
 

-class Document(models.Model):
-    """
-        File in repository.        
-    """
-    creator = models.ForeignKey(User, null=True, blank=True)
-    head = models.ForeignKey(Change,
-                    null=True, blank=True, default=None,
-                    help_text=_("This document's current head."))
+@python_2_unicode_compatible
+class Ref(models.Model):
+    """A reference pointing to a specific revision."""

 
 

-    @classmethod
-    def create(cls, text='', *args, **kwargs):
-        instance = cls(*args, **kwargs)
-        instance.save()
-        head = instance.head
-        head.patch = Change.make_patch('', text)
-        head.save()
-        return instance
-
-    def __unicode__(self):
-        return u"{0}, HEAD: {1}".format(self.id, self.head_id)
-
-    @models.permalink
-    def get_absolute_url(self):
-        return ('dvcs.views.document_data', (), {
-                        'document_id': self.id,
-                        'version': 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, **kwargs):
-        if 'parent' not in kwargs:
-            parent = self.head
-        else:
-            parent = kwargs['parent']
-            if not isinstance(parent, Change):
-                parent = Change.objects.get(pk=kwargs['parent'])
-
-        if 'patch' not in kwargs:
-            if 'text' not in kwargs:
-                raise ValueError("You must provide either patch or target document.")
-            patch = Change.make_patch(self.materialize(change=parent), kwargs['text'])
-        else:
-            if 'text' in kwargs:
-                raise ValueError("You can provide only text or patch - not both")
-            patch = kwargs['patch']
-
-        old_head = self.head
-        if parent != old_head:
-            change = parent.make_merge_child(patch, kwargs['author'], kwargs.get('description', ''))
-            # not Fast-Forward - perform a merge
-            self.head = old_head.merge_with(change, author=kwargs['author'])
+    revision = models.ForeignKey(
+        Revision, null=True, blank=True, default=None, verbose_name=_('revision'),
+        help_text=_("The document's revision."), editable=False)
+
+    def __str__(self):
+        return "ref:{0}->rev:{1}".format(self.id, self.revision_id)
+
+    def merge_text(self, base, local, remote):
+        """Override in subclass to have different kinds of merges."""
+        files = []
+        for f in local, base, remote:
+            temp = NamedTemporaryFile(delete=False)
+            temp.write(f)
+            temp.close()
+            files.append(temp.name)
+        p = Popen(['/usr/bin/diff3', '-mE', '-L', 'old', '-L', '', '-L', 'new'] + files, stdout=PIPE)
+        result, errs = p.communicate()
+
+        for f in files:
+            os.unlink(f)
+        return result.decode('utf-8')
+
+    def merge_with(self, revision, author=None, author_name=None, author_email=None, description="Automatic merge."):
+        """Merges a given revision into the ref."""
+        if self.revision is None:
+            fast_forward = True
+            self.revision = revision
+        elif self.revision.pk == revision.pk or self.revision.is_descendant_of(revision):
+            # Already merged.
+            return
+        elif revision.is_descendant_of(self.revision):
+            # Fast forward.
+            fast_forward = True
+            self.revision = revision

         else:
         else:

-            self.head = parent.make_child(patch, kwargs['author'], kwargs.get('description', ''))
+            # Need to create a merge revision.
+            fast_forward = False
+            base = self.revision.get_common_ancestor_with(revision)
+
+            local_text = self.materialize().encode('utf-8')
+            base_text = base.materialize().encode('utf-8')
+            other_text = revision.materialize().encode('utf-8')

 
 

+            merge_text = self.merge_text(base_text, local_text, other_text)
+
+            merge_revision = Revision.create(
+                text=merge_text,
+                parent=self.revision,
+                merge_parent=revision,
+                author=author,
+                author_name=author_name,
+                author_email=author_email,
+                description=description
+            )
+            self.revision = merge_revision

         self.save()
         self.save()

-        return self.head
+        post_merge.send(sender=type(self), instance=self, fast_forward=fast_forward)

 
 

-    def history(self):
-        return self.change_set.all()
+    def materialize(self):
+        return self.revision.materialize() if self.revision is not None else ''

 
 

-    def revision(self):
-        return self.change_set.all().count()
+    def commit(self, text, parent=False, author=None, author_name=None, author_email=None, description=''):
+        """Creates a new revision and sets it as the ref.

 
 

-    def at_revision(self, rev):
-        if rev:
-            return self.change_set.all()[rev-1]
-        else:
-            return self.head
-
-    @staticmethod
-    def listener_initial_commit(sender, instance, created, **kwargs):
-        if created:
-            instance.head = Change.objects.create(
-                    author=instance.creator,
-                    patch=Change.make_patch('', ''),
-                    tree=instance)
-            instance.save()
-
-models.signals.post_save.connect(Document.listener_initial_commit, sender=Document)
+        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 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)
+        :returns: new head
+        """
+        if parent is False:
+            # If parent revision not set explicitly, use your head.
+            parent = self.revision
+
+        # Warning: this will silently leave revs unreferenced.
+        rev = Revision.create(
+                text=text,
+                author=author,
+                author_name=author_name,
+                author_email=author_email,
+                description=description,
+                parent=parent
+            )
+        self.merge_with(rev, author=author, author_name=author_name, author_email=author_email)
+
+        post_commit.send(sender=type(self), instance=self)
+
+    def history(self):
+        revs = self.revision.get_ancestors()
+        revs.add(self.revision)
+        return sorted(revs, key=lambda x: x.created_at)