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"""XML externalization support."""
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# "XML is like violence: if it doesn't solve your problem, you aren't
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# using enough of it." -- various
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# importing this module is fairly slow because it has to load several
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__copyright__ = "Copyright (C) 2005 Canonical Ltd."
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__author__ = "Martin Pool <mbp@canonical.com>"
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from util.cElementTree import ElementTree, SubElement, Element
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from cElementTree import Element, ElementTree, SubElement
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except ImportError:
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from util.elementtree.ElementTree import ElementTree, SubElement, Element
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from bzrlib.inventory import ROOT_ID, Inventory, InventoryEntry
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from bzrlib.revision import Revision, RevisionReference
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from bzrlib.errors import BzrError
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class Serializer(object):
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"""Abstract object serialize/deserialize"""
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def write_inventory(self, inv, f):
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"""Write inventory to a file"""
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elt = self._pack_inventory(inv)
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self._write_element(elt, f)
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def read_inventory(self, f):
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return self._unpack_inventory(self._read_element(f))
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def write_revision(self, rev, f):
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self._write_element(self._pack_revision(rev), f)
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def read_revision(self, f):
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return self._unpack_revision(self._read_element(f))
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def _write_element(self, elt, f):
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ElementTree(elt).write(f, 'utf-8')
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from elementtree.ElementTree import Element, ElementTree, SubElement
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from trace import mutter
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raise Exception("XMLMixin.to_element must be overridden in concrete classes")
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def write_xml(self, f):
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ElementTree(self.to_element()).write(f, 'utf-8')
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def _read_element(self, f):
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return ElementTree().parse(f)
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class _Serializer_v4(Serializer):
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"""Version 0.0.4 serializer
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You should use the serialzer_v4 singleton."""
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def _pack_inventory(self, inv):
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"""Convert to XML Element"""
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e = Element('inventory')
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if inv.root.file_id not in (None, ROOT_ID):
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e.set('file_id', inv.root.file_id)
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for path, ie in inv.iter_entries():
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e.append(self._pack_entry(ie))
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def _pack_entry(self, ie):
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"""Convert InventoryEntry to XML element"""
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e.set('name', ie.name)
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e.set('file_id', ie.file_id)
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e.set('kind', ie.kind)
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if ie.text_size != None:
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e.set('text_size', '%d' % ie.text_size)
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for f in ['text_id', 'text_sha1']:
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# to be conservative, we don't externalize the root pointers
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# for now, leaving them as null in the xml form. in a future
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# version it will be implied by nested elements.
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if ie.parent_id != ROOT_ID:
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assert isinstance(ie.parent_id, basestring)
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e.set('parent_id', ie.parent_id)
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def _unpack_inventory(self, elt):
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"""Construct from XML Element
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assert elt.tag == 'inventory'
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root_id = elt.get('file_id') or ROOT_ID
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inv = Inventory(root_id)
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ie = self._unpack_entry(e)
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if ie.parent_id == ROOT_ID:
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ie.parent_id = root_id
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def _unpack_entry(self, elt):
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assert elt.tag == 'entry'
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## original format inventories don't have a parent_id for
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## nodes in the root directory, but it's cleaner to use one
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parent_id = elt.get('parent_id')
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if parent_id == None:
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ie = InventoryEntry(elt.get('file_id'),
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ie.text_id = elt.get('text_id')
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ie.text_sha1 = elt.get('text_sha1')
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## mutter("read inventoryentry: %r" % (elt.attrib))
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v = elt.get('text_size')
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ie.text_size = v and int(v)
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def _pack_revision(self, rev):
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"""Revision object -> xml tree"""
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root = Element('revision',
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committer = rev.committer,
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timestamp = '%.9f' % rev.timestamp,
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revision_id = rev.revision_id,
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inventory_id = rev.inventory_id,
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inventory_sha1 = rev.inventory_sha1,
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root.set('timezone', str(rev.timezone))
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msg = SubElement(root, 'message')
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msg.text = rev.message
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pelts = SubElement(root, 'parents')
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pelts.tail = pelts.text = '\n'
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for rr in rev.parents:
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assert isinstance(rr, RevisionReference)
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p = SubElement(pelts, 'revision_ref')
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assert rr.revision_id
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p.set('revision_id', rr.revision_id)
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p.set('revision_sha1', rr.revision_sha1)
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def _unpack_revision(self, elt):
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"""XML Element -> Revision object"""
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# <changeset> is deprecated...
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if elt.tag not in ('revision', 'changeset'):
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raise BzrError("unexpected tag in revision file: %r" % elt)
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rev = Revision(committer = elt.get('committer'),
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timestamp = float(elt.get('timestamp')),
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revision_id = elt.get('revision_id'),
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inventory_id = elt.get('inventory_id'),
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inventory_sha1 = elt.get('inventory_sha1')
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precursor = elt.get('precursor')
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precursor_sha1 = elt.get('precursor_sha1')
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pelts = elt.find('parents')
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assert p.tag == 'revision_ref', \
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"bad parent node tag %r" % p.tag
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rev_ref = RevisionReference(p.get('revision_id'),
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p.get('revision_sha1'))
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rev.parents.append(rev_ref)
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prec_parent = rev.parents[0].revision_id
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assert prec_parent == precursor
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# revisions written prior to 0.0.5 have a single precursor
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# give as an attribute
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rev_ref = RevisionReference(precursor, precursor_sha1)
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rev.parents.append(rev_ref)
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v = elt.get('timezone')
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rev.timezone = v and int(v)
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rev.message = elt.findtext('message') # text of <message>
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"""singleton instance"""
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serializer_v4 = _Serializer_v4()
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return cls.from_element(ElementTree().parse(f))
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read_xml = classmethod(read_xml)