simplify dvcs storage

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

diff --git a/apps/dvcs/models.py b/apps/dvcs/models.py
index 47e7c26..1668dee 100644 (file)
--- a/apps/dvcs/models.py
+++ b/apps/dvcs/models.py
@@ -1,8 +1,66 @@
+from datetime import datetime
+
+from django.core.files.base import ContentFile
+from django.core.files.storage import FileSystemStorage

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

+from django.db.models.base import ModelBase

 from django.contrib.auth.models import User
 from django.utils.translation import ugettext_lazy as _
 from mercurial import mdiff, simplemerge
 from django.contrib.auth.models import User
 from django.utils.translation import ugettext_lazy as _
 from mercurial import mdiff, simplemerge

-import pickle
+
+from dvcs.fields import GzipFileSystemStorage
+from dvcs.settings import REPO_PATH
+
+
+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 next(self):
+        """
+            Returns the next tag - stage to work on.
+            Returns None for the last stage.
+        """
+        try:
+            return Tag.objects.filter(ordering__gt=self.ordering)[0]
+        except IndexError:
+            return None
+
+models.signals.pre_save.connect(Tag.listener_changed, sender=Tag)
+
+
+repo = GzipFileSystemStorage(location=REPO_PATH)
+
+def data_upload_to(instance, filename):
+    return "%d/%d" % (instance.tree.pk, instance.pk)

 
 class Change(models.Model):
     """
 
 class Change(models.Model):
     """


@@ -10,11 +68,13 @@ class Change(models.Model):
         argument points to the version against which this change has been 
         recorded. Initial text will have a null 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.
+        Data file contains a gzipped text of the document.

     """
     """

-    author = models.ForeignKey(User)
-    patch = models.TextField(blank=True)
-    tree = models.ForeignKey('Document')
+    author = models.ForeignKey(User, null=True, blank=True)
+    author_name = models.CharField(max_length=128, null=True, blank=True)
+    author_email = models.CharField(max_length=128, null=True, blank=True)
+    data = models.FileField(upload_to=data_upload_to, storage=repo)
+    revision = models.IntegerField(db_index=True)

 
     parent = models.ForeignKey('self',
                         null=True, blank=True, default=None,
 
     parent = models.ForeignKey('self',
                         null=True, blank=True, default=None,


@@ -25,73 +85,135 @@ class Change(models.Model):
                         related_name="merge_children")
 
     description = models.TextField(blank=True, default='')
                         related_name="merge_children")
 
     description = models.TextField(blank=True, default='')

-    created_at = models.DateTimeField(auto_now_add=True)
+    created_at = models.DateTimeField(editable=False, db_index=True, 
+                        default=datetime.now)
+    publishable = models.BooleanField(default=False)

 
     class Meta:
 
     class Meta:

+        abstract = True

         ordering = ('created_at',)
         ordering = ('created_at',)

+        unique_together = ['tree', 'revision']

 
     def __unicode__(self):
 
     def __unicode__(self):

-        return u"Id: %r, Tree %r, Parent %r, Patch '''\n%s'''" % (self.id, self.tree_id, self.parent_id, self.patch)
+        return u"Id: %r, Tree %r, Parent %r, Data: %s" % (self.id, self.tree_id, self.parent_id, self.data)

 
 

-    @staticmethod
-    def make_patch(src, dst):
-        return pickle.dumps(mdiff.textdiff(src, dst))
+    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 = 0
+            else:
+                self.revision = tree_rev + 1
+        return super(Change, self).save(*args, **kwargs)

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

-        changes = Change.objects.exclude(parent=None).filter(
-                        tree=self.tree,
-                        created_at__lte=self.created_at).order_by('created_at')
-        text = u''
-        for change in changes:
-            text = change.apply_to(text)
-        return text
-
-    def make_child(self, patch, author, description):
-        return self.children.create(patch=patch,
-                        tree=self.tree, author=author,
-                        description=description)
-
-    def make_merge_child(self, patch, author, description):
-        return self.merge_children.create(patch=patch,
-                        tree=self.tree, author=author,
-                        description=description)
-
-    def apply_to(self, text):
-        return mdiff.patch(text, pickle.loads(self.patch.encode('ascii')))
-
-    def merge_with(self, other, author, description=u"Automatic merge."):
+        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:
         assert self.tree_id == other.tree_id  # same tree
         if other.parent_id == self.pk:

-            # immediate child 
+            # immediate child - fast forward

             return other
 
             return other
 

-        local = self.materialize()
-        base = other.merge_parent.materialize()
-        remote = other.apply_to(base)
+        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 = 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)
+        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 create_tag_model(model):
+    name = model.__name__ + 'Tag'
+    attrs = {
+        '__module__': model.__module__,
+    }
+    return type(name, (Tag,), attrs)
+
+
+def create_change_model(model):
+    name = model.__name__ + 'Change'
+
+    attrs = {
+        '__module__': model.__module__,
+        'tree': models.ForeignKey(model, related_name='change_set'),
+        'tags': models.ManyToManyField(model.tag_model, related_name='change_set'),
+    }
+    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, 
+                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,
+                    help_text=_("This document's current head."),
+                    editable=False).contribute_to_class(model, 'head')
+
+        return model
+

 
 
 class Document(models.Model):
     """
         File in repository.        
     """
 
 
 class Document(models.Model):
     """
         File in repository.        
     """

-    creator = models.ForeignKey(User)
-    head = models.ForeignKey(Change,
-                    null=True, blank=True, default=None,
-                    help_text=_("This document's current head."))
+    __metaclass__ = DocumentMeta
+
+    creator = models.ForeignKey(User, null=True, blank=True, editable=False,
+                related_name="created_documents")
+
+    user = models.ForeignKey(User, null=True, blank=True)

 
 

-    # Some meta-data
-    name = models.CharField(max_length=200,
-                help_text=_("Name for this file to display."))
+    class Meta:
+        abstract = True

 
     def __unicode__(self):
 
     def __unicode__(self):

-        return u"{0}, HEAD: {1}".format(self.name, self.head_id)
+        return u"{0}, HEAD: {1}".format(self.id, self.head_id)

 
     @models.permalink
     def get_absolute_url(self):
 
     @models.permalink
     def get_absolute_url(self):


@@ -100,52 +222,66 @@ class Document(models.Model):
                         'version': self.head_id,
         })
 
                         'version': self.head_id,
         })
 

-    def materialize(self, version=None):
+    def materialize(self, change=None):

         if self.head is None:
             return u''
         if self.head is None:
             return u''

-        if version is None:
-            version = self.head
-        elif not isinstance(version, Change):
-            version = self.change_set.get(pk=version)
-        return version.materialize()
+        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):
+    def commit(self, text, **kwargs):

         if 'parent' not in kwargs:
             parent = self.head
         else:
             parent = kwargs['parent']
         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 parent is not None and not isinstance(parent, Change):
+                parent = self.change_set.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(version=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'])
+        author = kwargs.get('author', None)
+        author_name = kwargs.get('author_name', None)
+        author_email = kwargs.get('author_email', None)
+        tags = kwargs.get('tags', [])
+        if tags:
+            # set stage to next tag after the commited one
+            self.stage = max(tags, key=lambda t: t.ordering).next()
+
+        change = self.change_set.create(author=author,
+                    author_name=author_name,
+                    author_email=author_email,
+                    description=kwargs.get('description', ''),
+                    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:
         else:

-            self.head = parent.make_child(patch, kwargs['author'], kwargs.get('description', ''))
+            self.head = change

         self.save()
         return self.head
 
     def history(self):
         self.save()
         return self.head
 
     def history(self):

-        return self.changes.all()
+        return self.change_set.filter(revision__gt=-1)

 
 

-    @staticmethod
-    def listener_initial_commit(sender, instance, created, **kwargs):
-        if created:
-            instance.head = Change.objects.create(
-                    author=instance.creator,
-                    patch=pickle.dumps(mdiff.textdiff('', '')),
-                    tree=instance)
-            instance.save()
-
-models.signals.post_save.connect(Document.listener_initial_commit, sender=Document)
+    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.change_set.filter(publishable=True).order_by('-created_at')[:1]
+        if changes.count():
+            return changes[0]
+        else:
+            return None