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# Copyright (C) 2005, 2006 by Canonical Ltd
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# Written by Martin Pool.
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# Modified by Johan Rydberg <jrydberg@gnu.org>
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# Modified by Robert Collins <robert.collins@canonical.com>
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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"""Knit versionedfile implementation.
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A knit is a versioned file implementation that supports efficient append only
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lifeless: the data file is made up of "delta records". each delta record has a delta header
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that contains; (1) a version id, (2) the size of the delta (in lines), and (3) the digest of
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the -expanded data- (ie, the delta applied to the parent). the delta also ends with a
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end-marker; simply "end VERSION"
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delta can be line or full contents.a
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... the 8's there are the index number of the annotation.
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version robertc@robertcollins.net-20051003014215-ee2990904cc4c7ad 7 c7d23b2a5bd6ca00e8e266cec0ec228158ee9f9e
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8 e.set('executable', 'yes')
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8 if elt.get('executable') == 'yes':
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8 ie.executable = True
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end robertc@robertcollins.net-20051003014215-ee2990904cc4c7ad
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09:33 < jrydberg> lifeless: each index is made up of a tuple of; version id, options, position, size, parents
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09:33 < jrydberg> lifeless: the parents are currently dictionary compressed
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09:33 < jrydberg> lifeless: (meaning it currently does not support ghosts)
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09:33 < lifeless> right
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09:33 < jrydberg> lifeless: the position and size is the range in the data file
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so the index sequence is the dictionary compressed sequence number used
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in the deltas to provide line annotation
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# 10:16 < lifeless> make partial index writes safe
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# 10:16 < lifeless> implement 'knit.check()' like weave.check()
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# 10:17 < lifeless> record known ghosts so we can detect when they are filled in rather than the current 'reweave
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# move sha1 out of the content so that join is faster at verifying parents
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# record content length ?
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from cStringIO import StringIO
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from itertools import izip, chain
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import bzrlib.errors as errors
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from bzrlib.errors import FileExists, NoSuchFile, KnitError, \
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InvalidRevisionId, KnitCorrupt, KnitHeaderError, \
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RevisionNotPresent, RevisionAlreadyPresent
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from bzrlib.tuned_gzip import *
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from bzrlib.trace import mutter
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from bzrlib.osutils import contains_whitespace, contains_linebreaks, \
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from bzrlib.versionedfile import VersionedFile, InterVersionedFile
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from bzrlib.tsort import topo_sort
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# TODO: Split out code specific to this format into an associated object.
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# TODO: Can we put in some kind of value to check that the index and data
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# files belong together?
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# TODO: accomodate binaries, perhaps by storing a byte count
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# TODO: function to check whole file
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# TODO: atomically append data, then measure backwards from the cursor
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# position after writing to work out where it was located. we may need to
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# bypass python file buffering.
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INDEX_SUFFIX = '.kndx'
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class KnitContent(object):
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"""Content of a knit version to which deltas can be applied."""
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def __init__(self, lines):
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def annotate_iter(self):
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"""Yield tuples of (origin, text) for each content line."""
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for origin, text in self._lines:
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"""Return a list of (origin, text) tuples."""
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return list(self.annotate_iter())
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def line_delta_iter(self, new_lines):
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"""Generate line-based delta from this content to new_lines."""
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new_texts = [text for origin, text in new_lines._lines]
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old_texts = [text for origin, text in self._lines]
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s = SequenceMatcher(None, old_texts, new_texts)
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for op in s.get_opcodes():
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# ofrom oto length data
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yield (op[1], op[2], op[4]-op[3], new_lines._lines[op[3]:op[4]])
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def line_delta(self, new_lines):
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return list(self.line_delta_iter(new_lines))
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return [text for origin, text in self._lines]
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class _KnitFactory(object):
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"""Base factory for creating content objects."""
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def make(self, lines, version):
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num_lines = len(lines)
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return KnitContent(zip([version] * num_lines, lines))
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class KnitAnnotateFactory(_KnitFactory):
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"""Factory for creating annotated Content objects."""
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def parse_fulltext(self, content, version):
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"""Convert fulltext to internal representation
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fulltext content is of the format
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revid(utf8) plaintext\n
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internal representation is of the format:
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origin, text = line.split(' ', 1)
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lines.append((origin.decode('utf-8'), text))
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return KnitContent(lines)
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def parse_line_delta_iter(self, lines):
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for result_item in self.parse_line_delta[lines]:
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def parse_line_delta(self, lines, version):
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"""Convert a line based delta into internal representation.
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line delta is in the form of:
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intstart intend intcount
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revid(utf8) newline\n
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internal represnetation is
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(start, end, count, [1..count tuples (revid, newline)])
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# walk through the lines parsing.
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start, end, count = [int(n) for n in header.split(',')]
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origin, text = next().split(' ', 1)
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contents.append((origin.decode('utf-8'), text))
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result.append((start, end, count, contents))
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def lower_fulltext(self, content):
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"""convert a fulltext content record into a serializable form.
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see parse_fulltext which this inverts.
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return ['%s %s' % (o.encode('utf-8'), t) for o, t in content._lines]
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def lower_line_delta(self, delta):
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"""convert a delta into a serializable form.
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See parse_line_delta which this inverts.
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for start, end, c, lines in delta:
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out.append('%d,%d,%d\n' % (start, end, c))
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for origin, text in lines:
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out.append('%s %s' % (origin.encode('utf-8'), text))
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class KnitPlainFactory(_KnitFactory):
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"""Factory for creating plain Content objects."""
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def parse_fulltext(self, content, version):
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"""This parses an unannotated fulltext.
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Note that this is not a noop - the internal representation
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has (versionid, line) - its just a constant versionid.
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return self.make(content, version)
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def parse_line_delta_iter(self, lines, version):
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header = lines.pop(0)
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start, end, c = [int(n) for n in header.split(',')]
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yield start, end, c, zip([version] * c, lines[:c])
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def parse_line_delta(self, lines, version):
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return list(self.parse_line_delta_iter(lines, version))
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def lower_fulltext(self, content):
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return content.text()
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def lower_line_delta(self, delta):
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for start, end, c, lines in delta:
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out.append('%d,%d,%d\n' % (start, end, c))
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out.extend([text for origin, text in lines])
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def make_empty_knit(transport, relpath):
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"""Construct a empty knit at the specified location."""
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k = KnitVersionedFile(transport, relpath, 'w', KnitPlainFactory)
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class KnitVersionedFile(VersionedFile):
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"""Weave-like structure with faster random access.
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A knit stores a number of texts and a summary of the relationships
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between them. Texts are identified by a string version-id. Texts
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are normally stored and retrieved as a series of lines, but can
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also be passed as single strings.
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Lines are stored with the trailing newline (if any) included, to
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avoid special cases for files with no final newline. Lines are
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composed of 8-bit characters, not unicode. The combination of
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these approaches should mean any 'binary' file can be safely
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stored and retrieved.
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def __init__(self, relpath, transport, file_mode=None, access_mode=None, factory=None,
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basis_knit=None, delta=True, create=False):
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"""Construct a knit at location specified by relpath.
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:param create: If not True, only open an existing knit.
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if access_mode is None:
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super(KnitVersionedFile, self).__init__(access_mode)
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assert access_mode in ('r', 'w'), "invalid mode specified %r" % access_mode
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assert not basis_knit or isinstance(basis_knit, KnitVersionedFile), \
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self.transport = transport
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self.filename = relpath
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self.basis_knit = basis_knit
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self.factory = factory or KnitAnnotateFactory()
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self.writable = (access_mode == 'w')
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self._index = _KnitIndex(transport, relpath + INDEX_SUFFIX,
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access_mode, create=create)
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self._data = _KnitData(transport, relpath + DATA_SUFFIX,
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access_mode, create=not len(self.versions()))
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def _add_delta(self, version_id, parents, delta_parent, sha1, noeol, delta):
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"""See VersionedFile._add_delta()."""
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self._check_add(version_id, []) # should we check the lines ?
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self._check_versions_present(parents)
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for parent in parents:
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if not self.has_version(parent):
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ghosts.append(parent)
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present_parents.append(parent)
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if delta_parent is None:
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# reconstitute as full text.
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assert len(delta) == 1 or len(delta) == 0
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assert delta[0][0] == 0
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assert delta[0][1] == 0, delta[0][1]
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return super(KnitVersionedFile, self)._add_delta(version_id,
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options.append('no-eol')
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if delta_parent is not None:
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# determine the current delta chain length.
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# To speed the extract of texts the delta chain is limited
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# to a fixed number of deltas. This should minimize both
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# I/O and the time spend applying deltas.
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delta_parents = [delta_parent]
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parent = delta_parents[0]
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method = self._index.get_method(parent)
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if method == 'fulltext':
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delta_parents = self._index.get_parents(parent)
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if method == 'line-delta':
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# did not find a fulltext in the delta limit.
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# just do a normal insertion.
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return super(KnitVersionedFile, self)._add_delta(version_id,
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options.append('line-delta')
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store_lines = self.factory.lower_line_delta(delta)
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where, size = self._data.add_record(version_id, digest, store_lines)
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self._index.add_version(version_id, options, where, size, parents)
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def clear_cache(self):
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"""Clear the data cache only."""
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self._data.clear_cache()
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def copy_to(self, name, transport):
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"""See VersionedFile.copy_to()."""
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# copy the current index to a temp index to avoid racing with local
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transport.put(name + INDEX_SUFFIX + '.tmp', self.transport.get(self._index._filename))
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transport.put(name + DATA_SUFFIX, self._data._open_file())
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# rename the copied index into place
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transport.rename(name + INDEX_SUFFIX + '.tmp', name + INDEX_SUFFIX)
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def create_empty(self, name, transport, mode=None):
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return KnitVersionedFile(name, transport, factory=self.factory, delta=self.delta, create=True)
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def _fix_parents(self, version, new_parents):
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"""Fix the parents list for version.
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This is done by appending a new version to the index
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with identical data except for the parents list.
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the parents list must be a superset of the current
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current_values = self._index._cache[version]
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assert set(current_values[4]).difference(set(new_parents)) == set()
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self._index.add_version(version,
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def get_delta(self, version_id):
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"""Get a delta for constructing version from some other version."""
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if not self.has_version(version_id):
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raise RevisionNotPresent(version_id, self.filename)
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parents = self.get_parents(version_id)
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data_pos, data_size = self._index.get_position(version_id)
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data, sha1 = self._data.read_records(((version_id, data_pos, data_size),))[version_id]
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version_idx = self._index.lookup(version_id)
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noeol = 'no-eol' in self._index.get_options(version_id)
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if 'fulltext' == self._index.get_method(version_id):
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new_content = self.factory.parse_fulltext(data, version_idx)
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if parent is not None:
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reference_content = self._get_content(parent)
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old_texts = reference_content.text()
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new_texts = new_content.text()
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delta_seq = SequenceMatcher(None, old_texts, new_texts)
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return parent, sha1, noeol, self._make_line_delta(delta_seq, new_content)
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delta = self.factory.parse_line_delta(data, version_idx)
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return parent, sha1, noeol, delta
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def get_graph_with_ghosts(self):
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"""See VersionedFile.get_graph_with_ghosts()."""
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graph_items = self._index.get_graph()
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return dict(graph_items)
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"""See VersionedFile.get_suffixes()."""
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return [DATA_SUFFIX, INDEX_SUFFIX]
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def has_ghost(self, version_id):
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"""True if there is a ghost reference in the file to version_id."""
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if self.has_version(version_id):
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# optimisable if needed by memoising the _ghosts set.
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items = self._index.get_graph()
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for node, parents in items:
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for parent in parents:
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if parent not in self._index._cache:
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if parent == version_id:
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"""See VersionedFile.versions."""
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return self._index.get_versions()
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def has_version(self, version_id):
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"""See VersionedFile.has_version."""
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return self._index.has_version(version_id)
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__contains__ = has_version
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def _merge_annotations(self, content, parents, parent_texts={},
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delta=None, annotated=None):
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"""Merge annotations for content. This is done by comparing
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the annotations based on changed to the text.
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for parent_id in parents:
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merge_content = self._get_content(parent_id, parent_texts)
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seq = SequenceMatcher(None, merge_content.text(), content.text())
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if delta_seq is None:
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# setup a delta seq to reuse.
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for i, j, n in seq.get_matching_blocks():
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# this appears to copy (origin, text) pairs across to the new
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# content for any line that matches the last-checked parent.
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# FIXME: save the sequence control data for delta compression
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# against the most relevant parent rather than rediffing.
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content._lines[j:j+n] = merge_content._lines[i:i+n]
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reference_content = self._get_content(parents[0], parent_texts)
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new_texts = content.text()
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old_texts = reference_content.text()
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delta_seq = SequenceMatcher(None, old_texts, new_texts)
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return self._make_line_delta(delta_seq, content)
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def _make_line_delta(self, delta_seq, new_content):
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"""Generate a line delta from delta_seq and new_content."""
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for op in delta_seq.get_opcodes():
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diff_hunks.append((op[1], op[2], op[4]-op[3], new_content._lines[op[3]:op[4]]))
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def _get_components(self, version_id):
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"""Return a list of (version_id, method, data) tuples that
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makes up version specified by version_id of the knit.
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The components should be applied in the order of the returned
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The basis knit will be used to the largest extent possible
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since it is assumed that accesses to it is faster.
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# 4168 calls in 14912, 2289 internal
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# 4168 in 9711 to read_records
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# 52554 in 1250 to get_parents
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# 170166 in 865 to list.append
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# needed_revisions holds a list of (method, version_id) of
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# versions that is needed to be fetched to construct the final
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# version of the file.
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# basis_revisions is a list of versions that needs to be
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# fetched but exists in the basis knit.
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basis = self.basis_knit
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if basis and basis._index.has_version(cursor):
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basis_versions.append(cursor)
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method = picked_knit._index.get_method(cursor)
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needed_versions.append((method, cursor))
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if method == 'fulltext':
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cursor = picked_knit.get_parents(cursor)[0]
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for comp_id in basis_versions:
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data_pos, data_size = basis._index.get_data_position(comp_id)
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records.append((piece_id, data_pos, data_size))
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components.update(basis._data.read_records(records))
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for comp_id in [vid for method, vid in needed_versions
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if vid not in basis_versions]:
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data_pos, data_size = self._index.get_position(comp_id)
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records.append((comp_id, data_pos, data_size))
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components.update(self._data.read_records(records))
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# get_data_records returns a mapping with the version id as
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# index and the value as data. The order the components need
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# to be applied is held by needed_versions (reversed).
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for method, comp_id in reversed(needed_versions):
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out.append((comp_id, method, components[comp_id]))
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def _get_content(self, version_id, parent_texts={}):
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"""Returns a content object that makes up the specified
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if not self.has_version(version_id):
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raise RevisionNotPresent(version_id, self.filename)
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cached_version = parent_texts.get(version_id, None)
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if cached_version is not None:
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return cached_version
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if self.basis_knit and version_id in self.basis_knit:
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return self.basis_knit._get_content(version_id)
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components = self._get_components(version_id)
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for component_id, method, (data, digest) in components:
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version_idx = self._index.lookup(component_id)
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if method == 'fulltext':
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assert content is None
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content = self.factory.parse_fulltext(data, version_idx)
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elif method == 'line-delta':
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delta = self.factory.parse_line_delta(data, version_idx)
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content._lines = self._apply_delta(content._lines, delta)
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if 'no-eol' in self._index.get_options(version_id):
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line = content._lines[-1][1].rstrip('\n')
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content._lines[-1] = (content._lines[-1][0], line)
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if sha_strings(content.text()) != digest:
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import pdb;pdb.set_trace()
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raise KnitCorrupt(self.filename, 'sha-1 does not match %s' % version_id)
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def _check_versions_present(self, version_ids):
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"""Check that all specified versions are present."""
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version_ids = set(version_ids)
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for r in list(version_ids):
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if self._index.has_version(r):
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version_ids.remove(r)
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raise RevisionNotPresent(list(version_ids)[0], self.filename)
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def _add_lines_with_ghosts(self, version_id, parents, lines, parent_texts):
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"""See VersionedFile.add_lines_with_ghosts()."""
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self._check_add(version_id, lines)
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return self._add(version_id, lines[:], parents, self.delta, parent_texts)
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def _add_lines(self, version_id, parents, lines, parent_texts):
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"""See VersionedFile.add_lines."""
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self._check_add(version_id, lines)
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self._check_versions_present(parents)
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return self._add(version_id, lines[:], parents, self.delta, parent_texts)
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def _check_add(self, version_id, lines):
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"""check that version_id and lines are safe to add."""
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assert self.writable, "knit is not opened for write"
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### FIXME escape. RBC 20060228
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if contains_whitespace(version_id):
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raise InvalidRevisionId(version_id)
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if self.has_version(version_id):
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raise RevisionAlreadyPresent(version_id, self.filename)
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if False or __debug__:
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assert '\n' not in l[:-1]
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def _add(self, version_id, lines, parents, delta, parent_texts):
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"""Add a set of lines on top of version specified by parents.
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If delta is true, compress the text as a line-delta against
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Any versions not present will be converted into ghosts.
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# 461 0 6546.0390 43.9100 bzrlib.knit:489(_add)
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# +400 0 889.4890 418.9790 +bzrlib.knit:192(lower_fulltext)
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# +461 0 1364.8070 108.8030 +bzrlib.knit:996(add_record)
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# +461 0 193.3940 41.5720 +bzrlib.knit:898(add_version)
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# +461 0 134.0590 18.3810 +bzrlib.osutils:361(sha_strings)
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# +461 0 36.3420 15.4540 +bzrlib.knit:146(make)
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# +1383 0 8.0370 8.0370 +<len>
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# +61 0 13.5770 7.9190 +bzrlib.knit:199(lower_line_delta)
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# +61 0 963.3470 7.8740 +bzrlib.knit:427(_get_content)
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# +61 0 973.9950 5.2950 +bzrlib.knit:136(line_delta)
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# +61 0 1918.1800 5.2640 +bzrlib.knit:359(_merge_annotations)
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if parent_texts is None:
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for parent in parents:
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if not self.has_version(parent):
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ghosts.append(parent)
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present_parents.append(parent)
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if delta and not len(present_parents):
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digest = sha_strings(lines)
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if lines[-1][-1] != '\n':
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options.append('no-eol')
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lines[-1] = lines[-1] + '\n'
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if len(present_parents) and delta:
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# To speed the extract of texts the delta chain is limited
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# to a fixed number of deltas. This should minimize both
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# I/O and the time spend applying deltas.
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delta_parents = present_parents
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parent = delta_parents[0]
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method = self._index.get_method(parent)
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if method == 'fulltext':
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delta_parents = self._index.get_parents(parent)
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if method == 'line-delta':
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lines = self.factory.make(lines, version_id)
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if delta or (self.factory.annotated and len(present_parents) > 0):
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# Merge annotations from parent texts if so is needed.
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delta_hunks = self._merge_annotations(lines, present_parents, parent_texts,
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delta, self.factory.annotated)
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options.append('line-delta')
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store_lines = self.factory.lower_line_delta(delta_hunks)
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options.append('fulltext')
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store_lines = self.factory.lower_fulltext(lines)
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where, size = self._data.add_record(version_id, digest, store_lines)
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self._index.add_version(version_id, options, where, size, parents)
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def check(self, progress_bar=None):
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"""See VersionedFile.check()."""
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def _clone_text(self, new_version_id, old_version_id, parents):
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"""See VersionedFile.clone_text()."""
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# FIXME RBC 20060228 make fast by only inserting an index with null delta.
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self.add_lines(new_version_id, parents, self.get_lines(old_version_id))
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def get_lines(self, version_id):
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"""See VersionedFile.get_lines()."""
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return self._get_content(version_id).text()
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def iter_lines_added_or_present_in_versions(self, version_ids=None):
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"""See VersionedFile.iter_lines_added_or_present_in_versions()."""
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if version_ids is None:
705
version_ids = self.versions()
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# we dont care about inclusions, the caller cares.
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# but we need to setup a list of records to visit.
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# we need version_id, position, length
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version_id_records = []
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requested_versions = list(version_ids)
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# filter for available versions
712
for version_id in requested_versions:
713
if not self.has_version(version_id):
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raise RevisionNotPresent(version_id, self.filename)
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# get a in-component-order queue:
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for version_id in self.versions():
718
if version_id in requested_versions:
719
version_ids.append(version_id)
720
data_pos, length = self._index.get_position(version_id)
721
version_id_records.append((version_id, data_pos, length))
723
pb = bzrlib.ui.ui_factory.nested_progress_bar()
725
total = len(version_id_records)
727
pb.update('Walking content.', count, total)
728
for version_id, data, sha_value in \
729
self._data.read_records_iter(version_id_records):
730
pb.update('Walking content.', count, total)
731
method = self._index.get_method(version_id)
732
version_idx = self._index.lookup(version_id)
733
assert method in ('fulltext', 'line-delta')
734
if method == 'fulltext':
735
content = self.factory.parse_fulltext(data, version_idx)
736
for line in content.text():
739
delta = self.factory.parse_line_delta(data, version_idx)
740
for start, end, count, lines in delta:
741
for origin, line in lines:
744
pb.update('Walking content.', total, total)
747
pb.update('Walking content.', total, total)
751
def num_versions(self):
752
"""See VersionedFile.num_versions()."""
753
return self._index.num_versions()
755
__len__ = num_versions
757
def annotate_iter(self, version_id):
758
"""See VersionedFile.annotate_iter."""
759
content = self._get_content(version_id)
760
for origin, text in content.annotate_iter():
763
def get_parents(self, version_id):
764
"""See VersionedFile.get_parents."""
767
# 52554 calls in 1264 872 internal down from 3674
769
return self._index.get_parents(version_id)
771
raise RevisionNotPresent(version_id, self.filename)
773
def get_parents_with_ghosts(self, version_id):
774
"""See VersionedFile.get_parents."""
776
return self._index.get_parents_with_ghosts(version_id)
778
raise RevisionNotPresent(version_id, self.filename)
780
def get_ancestry(self, versions):
781
"""See VersionedFile.get_ancestry."""
782
if isinstance(versions, basestring):
783
versions = [versions]
786
self._check_versions_present(versions)
787
return self._index.get_ancestry(versions)
789
def get_ancestry_with_ghosts(self, versions):
790
"""See VersionedFile.get_ancestry_with_ghosts."""
791
if isinstance(versions, basestring):
792
versions = [versions]
795
self._check_versions_present(versions)
796
return self._index.get_ancestry_with_ghosts(versions)
798
#@deprecated_method(zero_eight)
799
def walk(self, version_ids):
800
"""See VersionedFile.walk."""
801
# We take the short path here, and extract all relevant texts
802
# and put them in a weave and let that do all the work. Far
803
# from optimal, but is much simpler.
804
# FIXME RB 20060228 this really is inefficient!
805
from bzrlib.weave import Weave
807
w = Weave(self.filename)
808
ancestry = self.get_ancestry(version_ids)
809
sorted_graph = topo_sort(self._index.get_graph())
810
version_list = [vid for vid in sorted_graph if vid in ancestry]
812
for version_id in version_list:
813
lines = self.get_lines(version_id)
814
w.add_lines(version_id, self.get_parents(version_id), lines)
816
for lineno, insert_id, dset, line in w.walk(version_ids):
817
yield lineno, insert_id, dset, line
820
class _KnitComponentFile(object):
821
"""One of the files used to implement a knit database"""
823
def __init__(self, transport, filename, mode):
824
self._transport = transport
825
self._filename = filename
828
def write_header(self):
829
if self._transport.append(self._filename, StringIO(self.HEADER)):
830
raise KnitCorrupt(self._filename, 'misaligned after writing header')
832
def check_header(self, fp):
833
line = fp.read(len(self.HEADER))
834
if line != self.HEADER:
835
raise KnitHeaderError(badline=line)
838
"""Commit is a nop."""
841
return '%s(%s)' % (self.__class__.__name__, self._filename)
844
class _KnitIndex(_KnitComponentFile):
845
"""Manages knit index file.
847
The index is already kept in memory and read on startup, to enable
848
fast lookups of revision information. The cursor of the index
849
file is always pointing to the end, making it easy to append
852
_cache is a cache for fast mapping from version id to a Index
855
_history is a cache for fast mapping from indexes to version ids.
857
The index data format is dictionary compressed when it comes to
858
parent references; a index entry may only have parents that with a
859
lover index number. As a result, the index is topological sorted.
861
Duplicate entries may be written to the index for a single version id
862
if this is done then the latter one completely replaces the former:
863
this allows updates to correct version and parent information.
864
Note that the two entries may share the delta, and that successive
865
annotations and references MUST point to the first entry.
868
HEADER = "# bzr knit index 7\n"
870
# speed of knit parsing went from 280 ms to 280 ms with slots addition.
871
# __slots__ = ['_cache', '_history', '_transport', '_filename']
873
def _cache_version(self, version_id, options, pos, size, parents):
874
"""Cache a version record in the history array and index cache.
876
This is inlined into __init__ for performance. KEEP IN SYNC.
877
(It saves 60ms, 25% of the __init__ overhead on local 4000 record
880
# only want the _history index to reference the 1st index entry
882
if version_id not in self._cache:
883
index = len(self._history)
884
self._history.append(version_id)
886
index = self._cache[version_id][5]
887
self._cache[version_id] = (version_id,
894
def __init__(self, transport, filename, mode, create=False):
895
_KnitComponentFile.__init__(self, transport, filename, mode)
897
# position in _history is the 'official' index for a revision
898
# but the values may have come from a newer entry.
899
# so - wc -l of a knit index is != the number of uniqe names
902
pb = bzrlib.ui.ui_factory.nested_progress_bar()
907
pb.update('read knit index', count, total)
908
fp = self._transport.get(self._filename)
909
self.check_header(fp)
910
# readlines reads the whole file at once:
911
# bad for transports like http, good for local disk
912
# we save 60 ms doing this one change (
913
# from calling readline each time to calling
915
# probably what we want for nice behaviour on
916
# http is a incremental readlines that yields, or
917
# a check for local vs non local indexes,
918
for l in fp.readlines():
922
#pb.update('read knit index', count, total)
923
# See self._parse_parents
925
for value in rec[4:]:
927
# uncompressed reference
928
parents.append(value[1:])
930
# this is 15/4000ms faster than isinstance,
932
# this function is called thousands of times a
933
# second so small variations add up.
934
assert value.__class__ is str
935
parents.append(self._history[int(value)])
936
# end self._parse_parents
937
# self._cache_version(rec[0],
942
# --- self._cache_version
943
# only want the _history index to reference the 1st
944
# index entry for version_id
946
if version_id not in self._cache:
947
index = len(self._history)
948
self._history.append(version_id)
950
index = self._cache[version_id][5]
951
self._cache[version_id] = (version_id,
957
# --- self._cache_version
958
except NoSuchFile, e:
959
if mode != 'w' or not create:
963
pb.update('read knit index', total, total)
966
def _parse_parents(self, compressed_parents):
967
"""convert a list of string parent values into version ids.
969
ints are looked up in the index.
970
.FOO values are ghosts and converted in to FOO.
972
NOTE: the function is retained here for clarity, and for possible
973
use in partial index reads. However bulk processing now has
974
it inlined in __init__ for inner-loop optimisation.
977
for value in compressed_parents:
979
# uncompressed reference
980
result.append(value[1:])
982
# this is 15/4000ms faster than isinstance,
983
# this function is called thousands of times a
984
# second so small variations add up.
985
assert value.__class__ is str
986
result.append(self._history[int(value)])
991
for version_id, index in self._cache.iteritems():
992
graph.append((version_id, index[4]))
995
def get_ancestry(self, versions):
996
"""See VersionedFile.get_ancestry."""
997
# get a graph of all the mentioned versions:
999
pending = set(versions)
1001
version = pending.pop()
1002
parents = self._cache[version][4]
1003
# got the parents ok
1005
parents = [parent for parent in parents if parent in self._cache]
1006
for parent in parents:
1007
# if not completed and not a ghost
1008
if parent not in graph:
1010
graph[version] = parents
1011
return topo_sort(graph.items())
1013
def get_ancestry_with_ghosts(self, versions):
1014
"""See VersionedFile.get_ancestry_with_ghosts."""
1015
# get a graph of all the mentioned versions:
1017
pending = set(versions)
1019
version = pending.pop()
1021
parents = self._cache[version][4]
1027
# got the parents ok
1028
for parent in parents:
1029
if parent not in graph:
1031
graph[version] = parents
1032
return topo_sort(graph.items())
1034
def num_versions(self):
1035
return len(self._history)
1037
__len__ = num_versions
1039
def get_versions(self):
1040
return self._history
1042
def idx_to_name(self, idx):
1043
return self._history[idx]
1045
def lookup(self, version_id):
1046
assert version_id in self._cache
1047
return self._cache[version_id][5]
1049
def _version_list_to_index(self, versions):
1051
for version in versions:
1052
if version in self._cache:
1053
# -- inlined lookup() --
1054
result_list.append(str(self._cache[version][5]))
1055
# -- end lookup () --
1057
result_list.append('.' + version.encode('utf-8'))
1058
return ' '.join(result_list)
1060
def add_version(self, version_id, options, pos, size, parents):
1061
"""Add a version record to the index."""
1062
self._cache_version(version_id, options, pos, size, parents)
1064
content = "%s %s %s %s %s\n" % (version_id.encode('utf-8'),
1068
self._version_list_to_index(parents))
1069
assert isinstance(content, str), 'content must be utf-8 encoded'
1070
self._transport.append(self._filename, StringIO(content))
1072
def has_version(self, version_id):
1073
"""True if the version is in the index."""
1074
return self._cache.has_key(version_id)
1076
def get_position(self, version_id):
1077
"""Return data position and size of specified version."""
1078
return (self._cache[version_id][2], \
1079
self._cache[version_id][3])
1081
def get_method(self, version_id):
1082
"""Return compression method of specified version."""
1083
options = self._cache[version_id][1]
1084
if 'fulltext' in options:
1087
assert 'line-delta' in options
1090
def get_options(self, version_id):
1091
return self._cache[version_id][1]
1093
def get_parents(self, version_id):
1094
"""Return parents of specified version ignoring ghosts."""
1095
return [parent for parent in self._cache[version_id][4]
1096
if parent in self._cache]
1098
def get_parents_with_ghosts(self, version_id):
1099
"""Return parents of specified version wth ghosts."""
1100
return self._cache[version_id][4]
1102
def check_versions_present(self, version_ids):
1103
"""Check that all specified versions are present."""
1104
version_ids = set(version_ids)
1105
for version_id in list(version_ids):
1106
if version_id in self._cache:
1107
version_ids.remove(version_id)
1109
raise RevisionNotPresent(list(version_ids)[0], self.filename)
1112
class _KnitData(_KnitComponentFile):
1113
"""Contents of the knit data file"""
1115
HEADER = "# bzr knit data 7\n"
1117
def __init__(self, transport, filename, mode, create=False):
1118
_KnitComponentFile.__init__(self, transport, filename, mode)
1120
self._checked = False
1122
self._transport.put(self._filename, StringIO(''))
1125
def clear_cache(self):
1126
"""Clear the record cache."""
1129
def _open_file(self):
1130
if self._file is None:
1132
self._file = self._transport.get(self._filename)
1137
def _record_to_data(self, version_id, digest, lines):
1138
"""Convert version_id, digest, lines into a raw data block.
1140
:return: (len, a StringIO instance with the raw data ready to read.)
1143
data_file = GzipFile(None, mode='wb', fileobj=sio)
1144
data_file.writelines(chain(
1145
["version %s %d %s\n" % (version_id.encode('utf-8'),
1149
["end %s\n" % version_id.encode('utf-8')]))
1156
def add_raw_record(self, raw_data):
1157
"""Append a prepared record to the data file."""
1158
assert isinstance(raw_data, str), 'data must be plain bytes'
1159
start_pos = self._transport.append(self._filename, StringIO(raw_data))
1160
return start_pos, len(raw_data)
1162
def add_record(self, version_id, digest, lines):
1163
"""Write new text record to disk. Returns the position in the
1164
file where it was written."""
1165
size, sio = self._record_to_data(version_id, digest, lines)
1167
self._records[version_id] = (digest, lines)
1169
start_pos = self._transport.append(self._filename, sio)
1170
return start_pos, size
1172
def _parse_record_header(self, version_id, raw_data):
1173
"""Parse a record header for consistency.
1175
:return: the header and the decompressor stream.
1176
as (stream, header_record)
1178
df = GzipFile(mode='rb', fileobj=StringIO(raw_data))
1179
rec = df.readline().split()
1181
raise KnitCorrupt(self._filename, 'unexpected number of elements in record header')
1182
if rec[1].decode('utf-8')!= version_id:
1183
raise KnitCorrupt(self._filename,
1184
'unexpected version, wanted %r, got %r' % (
1185
version_id, rec[1]))
1188
def _parse_record(self, version_id, data):
1190
# 4168 calls in 2880 217 internal
1191
# 4168 calls to _parse_record_header in 2121
1192
# 4168 calls to readlines in 330
1193
df, rec = self._parse_record_header(version_id, data)
1194
record_contents = df.readlines()
1195
l = record_contents.pop()
1196
assert len(record_contents) == int(rec[2])
1197
if l.decode('utf-8') != 'end %s\n' % version_id:
1198
raise KnitCorrupt(self._filename, 'unexpected version end line %r, wanted %r'
1201
return record_contents, rec[3]
1203
def read_records_iter_raw(self, records):
1204
"""Read text records from data file and yield raw data.
1206
This unpacks enough of the text record to validate the id is
1207
as expected but thats all.
1209
It will actively recompress currently cached records on the
1210
basis that that is cheaper than I/O activity.
1213
for version_id, pos, size in records:
1214
if version_id not in self._records:
1215
needed_records.append((version_id, pos, size))
1217
# setup an iterator of the external records:
1218
# uses readv so nice and fast we hope.
1219
if len(needed_records):
1220
# grab the disk data needed.
1221
raw_records = self._transport.readv(self._filename,
1222
[(pos, size) for version_id, pos, size in needed_records])
1224
for version_id, pos, size in records:
1225
if version_id in self._records:
1226
# compress a new version
1227
size, sio = self._record_to_data(version_id,
1228
self._records[version_id][0],
1229
self._records[version_id][1])
1230
yield version_id, sio.getvalue()
1232
pos, data = raw_records.next()
1233
# validate the header
1234
df, rec = self._parse_record_header(version_id, data)
1236
yield version_id, data
1239
def read_records_iter(self, records):
1240
"""Read text records from data file and yield result.
1242
Each passed record is a tuple of (version_id, pos, len) and
1243
will be read in the given order. Yields (version_id,
1247
# 60890 calls for 4168 extractions in 5045, 683 internal.
1248
# 4168 calls to readv in 1411
1249
# 4168 calls to parse_record in 2880
1252
for version_id, pos, size in records:
1253
if version_id not in self._records:
1254
needed_records.append((version_id, pos, size))
1256
if len(needed_records):
1257
# We take it that the transport optimizes the fetching as good
1258
# as possible (ie, reads continous ranges.)
1259
response = self._transport.readv(self._filename,
1260
[(pos, size) for version_id, pos, size in needed_records])
1262
for (record_id, pos, size), (pos, data) in izip(iter(needed_records), response):
1263
content, digest = self._parse_record(record_id, data)
1264
self._records[record_id] = (digest, content)
1266
for version_id, pos, size in records:
1267
yield version_id, list(self._records[version_id][1]), self._records[version_id][0]
1269
def read_records(self, records):
1270
"""Read records into a dictionary."""
1272
for record_id, content, digest in self.read_records_iter(records):
1273
components[record_id] = (content, digest)
1277
class InterKnit(InterVersionedFile):
1278
"""Optimised code paths for knit to knit operations."""
1280
_matching_file_factory = KnitVersionedFile
1283
def is_compatible(source, target):
1284
"""Be compatible with knits. """
1286
return (isinstance(source, KnitVersionedFile) and
1287
isinstance(target, KnitVersionedFile))
1288
except AttributeError:
1291
def join(self, pb=None, msg=None, version_ids=None, ignore_missing=False):
1292
"""See InterVersionedFile.join."""
1293
assert isinstance(self.source, KnitVersionedFile)
1294
assert isinstance(self.target, KnitVersionedFile)
1296
if version_ids is None:
1297
version_ids = self.source.versions()
1299
if not ignore_missing:
1300
self.source._check_versions_present(version_ids)
1302
version_ids = set(self.source.versions()).intersection(
1308
pb = bzrlib.ui.ui_factory.nested_progress_bar()
1310
version_ids = list(version_ids)
1311
if None in version_ids:
1312
version_ids.remove(None)
1314
self.source_ancestry = set(self.source.get_ancestry(version_ids))
1315
this_versions = set(self.target._index.get_versions())
1316
needed_versions = self.source_ancestry - this_versions
1317
cross_check_versions = self.source_ancestry.intersection(this_versions)
1318
mismatched_versions = set()
1319
for version in cross_check_versions:
1320
# scan to include needed parents.
1321
n1 = set(self.target.get_parents_with_ghosts(version))
1322
n2 = set(self.source.get_parents_with_ghosts(version))
1324
# FIXME TEST this check for cycles being introduced works
1325
# the logic is we have a cycle if in our graph we are an
1326
# ancestor of any of the n2 revisions.
1332
parent_ancestors = self.source.get_ancestry(parent)
1333
if version in parent_ancestors:
1334
raise errors.GraphCycleError([parent, version])
1335
# ensure this parent will be available later.
1336
new_parents = n2.difference(n1)
1337
needed_versions.update(new_parents.difference(this_versions))
1338
mismatched_versions.add(version)
1340
if not needed_versions and not cross_check_versions:
1342
full_list = topo_sort(self.source.get_graph())
1344
version_list = [i for i in full_list if (not self.target.has_version(i)
1345
and i in needed_versions)]
1349
copy_queue_records = []
1351
for version_id in version_list:
1352
options = self.source._index.get_options(version_id)
1353
parents = self.source._index.get_parents_with_ghosts(version_id)
1354
# check that its will be a consistent copy:
1355
for parent in parents:
1356
# if source has the parent, we must :
1357
# * already have it or
1358
# * have it scheduled already
1359
# otherwise we dont care
1360
assert (self.target.has_version(parent) or
1361
parent in copy_set or
1362
not self.source.has_version(parent))
1363
data_pos, data_size = self.source._index.get_position(version_id)
1364
copy_queue_records.append((version_id, data_pos, data_size))
1365
copy_queue.append((version_id, options, parents))
1366
copy_set.add(version_id)
1368
# data suck the join:
1370
total = len(version_list)
1371
# we want the raw gzip for bulk copying, but the record validated
1372
# just enough to be sure its the right one.
1373
# TODO: consider writev or write combining to reduce
1374
# death of a thousand cuts feeling.
1375
for (version_id, raw_data), \
1376
(version_id2, options, parents) in \
1377
izip(self.source._data.read_records_iter_raw(copy_queue_records),
1379
assert version_id == version_id2, 'logic error, inconsistent results'
1381
pb.update("Joining knit", count, total)
1382
pos, size = self.target._data.add_raw_record(raw_data)
1383
self.target._index.add_version(version_id, options, pos, size, parents)
1385
for version in mismatched_versions:
1386
# FIXME RBC 20060309 is this needed?
1387
n1 = set(self.target.get_parents_with_ghosts(version))
1388
n2 = set(self.source.get_parents_with_ghosts(version))
1389
# write a combined record to our history preserving the current
1390
# parents as first in the list
1391
new_parents = self.target.get_parents_with_ghosts(version) + list(n2.difference(n1))
1392
self.target.fix_parents(version, new_parents)
1398
InterVersionedFile.register_optimiser(InterKnit)
1401
class SequenceMatcher(difflib.SequenceMatcher):
1402
"""Knit tuned sequence matcher.
1404
This is based on profiling of difflib which indicated some improvements
1405
for our usage pattern.
1408
def find_longest_match(self, alo, ahi, blo, bhi):
1409
"""Find longest matching block in a[alo:ahi] and b[blo:bhi].
1411
If isjunk is not defined:
1413
Return (i,j,k) such that a[i:i+k] is equal to b[j:j+k], where
1414
alo <= i <= i+k <= ahi
1415
blo <= j <= j+k <= bhi
1416
and for all (i',j',k') meeting those conditions,
1419
and if i == i', j <= j'
1421
In other words, of all maximal matching blocks, return one that
1422
starts earliest in a, and of all those maximal matching blocks that
1423
start earliest in a, return the one that starts earliest in b.
1425
>>> s = SequenceMatcher(None, " abcd", "abcd abcd")
1426
>>> s.find_longest_match(0, 5, 0, 9)
1429
If isjunk is defined, first the longest matching block is
1430
determined as above, but with the additional restriction that no
1431
junk element appears in the block. Then that block is extended as
1432
far as possible by matching (only) junk elements on both sides. So
1433
the resulting block never matches on junk except as identical junk
1434
happens to be adjacent to an "interesting" match.
1436
Here's the same example as before, but considering blanks to be
1437
junk. That prevents " abcd" from matching the " abcd" at the tail
1438
end of the second sequence directly. Instead only the "abcd" can
1439
match, and matches the leftmost "abcd" in the second sequence:
1441
>>> s = SequenceMatcher(lambda x: x==" ", " abcd", "abcd abcd")
1442
>>> s.find_longest_match(0, 5, 0, 9)
1445
If no blocks match, return (alo, blo, 0).
1447
>>> s = SequenceMatcher(None, "ab", "c")
1448
>>> s.find_longest_match(0, 2, 0, 1)
1452
# CAUTION: stripping common prefix or suffix would be incorrect.
1456
# Longest matching block is "ab", but if common prefix is
1457
# stripped, it's "a" (tied with "b"). UNIX(tm) diff does so
1458
# strip, so ends up claiming that ab is changed to acab by
1459
# inserting "ca" in the middle. That's minimal but unintuitive:
1460
# "it's obvious" that someone inserted "ac" at the front.
1461
# Windiff ends up at the same place as diff, but by pairing up
1462
# the unique 'b's and then matching the first two 'a's.
1464
a, b, b2j, isbjunk = self.a, self.b, self.b2j, self.isbjunk
1465
besti, bestj, bestsize = alo, blo, 0
1466
# find longest junk-free match
1467
# during an iteration of the loop, j2len[j] = length of longest
1468
# junk-free match ending with a[i-1] and b[j]
1472
for i in xrange(alo, ahi):
1473
# look at all instances of a[i] in b; note that because
1474
# b2j has no junk keys, the loop is skipped if a[i] is junk
1475
j2lenget = j2len.get
1478
# changing b2j.get(a[i], nothing) to a try:Keyerror pair produced the
1479
# following improvement
1480
# 704 0 4650.5320 2620.7410 bzrlib.knit:1336(find_longest_match)
1481
# +326674 0 1655.1210 1655.1210 +<method 'get' of 'dict' objects>
1482
# +76519 0 374.6700 374.6700 +<method 'has_key' of 'dict' objects>
1484
# 704 0 3733.2820 2209.6520 bzrlib.knit:1336(find_longest_match)
1485
# +211400 0 1147.3520 1147.3520 +<method 'get' of 'dict' objects>
1486
# +76519 0 376.2780 376.2780 +<method 'has_key' of 'dict' objects>
1498
k = newj2len[j] = 1 + j2lenget(-1 + j, 0)
1500
besti, bestj, bestsize = 1 + i-k, 1 + j-k, k
1503
# Extend the best by non-junk elements on each end. In particular,
1504
# "popular" non-junk elements aren't in b2j, which greatly speeds
1505
# the inner loop above, but also means "the best" match so far
1506
# doesn't contain any junk *or* popular non-junk elements.
1507
while besti > alo and bestj > blo and \
1508
not isbjunk(b[bestj-1]) and \
1509
a[besti-1] == b[bestj-1]:
1510
besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
1511
while besti+bestsize < ahi and bestj+bestsize < bhi and \
1512
not isbjunk(b[bestj+bestsize]) and \
1513
a[besti+bestsize] == b[bestj+bestsize]:
1516
# Now that we have a wholly interesting match (albeit possibly
1517
# empty!), we may as well suck up the matching junk on each
1518
# side of it too. Can't think of a good reason not to, and it
1519
# saves post-processing the (possibly considerable) expense of
1520
# figuring out what to do with it. In the case of an empty
1521
# interesting match, this is clearly the right thing to do,
1522
# because no other kind of match is possible in the regions.
1523
while besti > alo and bestj > blo and \
1524
isbjunk(b[bestj-1]) and \
1525
a[besti-1] == b[bestj-1]:
1526
besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
1527
while besti+bestsize < ahi and bestj+bestsize < bhi and \
1528
isbjunk(b[bestj+bestsize]) and \
1529
a[besti+bestsize] == b[bestj+bestsize]:
1530
bestsize = bestsize + 1
1532
return besti, bestj, bestsize
added
removed
bzrlib/knit.py
