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# Copyright (C) 2005, 2006 Canonical Ltd
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# Johan Rydberg <jrydberg@gnu.org>
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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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"""Versioned text file storage api."""
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from bzrlib.lazy_import import lazy_import
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lazy_import(globals(), """
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from bzrlib.transport.memory import MemoryTransport
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from cStringIO import StringIO
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from bzrlib.inter import InterObject
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from bzrlib.textmerge import TextMerge
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class VersionedFile(object):
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"""Versioned text file storage.
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A versioned file manages versions of line-based text files,
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keeping track of the originating version for each line.
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To clients the "lines" of the file are represented as a list of
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strings. These strings will typically have terminal newline
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characters, but this is not required. In particular files commonly
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do not have a newline at the end of the file.
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Texts are identified by a version-id string.
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def __init__(self, access_mode):
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self._access_mode = access_mode
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def check_not_reserved_id(version_id):
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revision.check_not_reserved_id(version_id)
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def copy_to(self, name, transport):
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"""Copy this versioned file to name on transport."""
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raise NotImplementedError(self.copy_to)
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"""Return a unsorted list of versions."""
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raise NotImplementedError(self.versions)
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def has_ghost(self, version_id):
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"""Returns whether version is present as a ghost."""
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raise NotImplementedError(self.has_ghost)
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def has_version(self, version_id):
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"""Returns whether version is present."""
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raise NotImplementedError(self.has_version)
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def add_lines(self, version_id, parents, lines, parent_texts=None,
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left_matching_blocks=None, nostore_sha=None, random_id=False,
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"""Add a single text on top of the versioned file.
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Must raise RevisionAlreadyPresent if the new version is
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already present in file history.
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Must raise RevisionNotPresent if any of the given parents are
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not present in file history.
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:param lines: A list of lines. Each line must be a bytestring. And all
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of them except the last must be terminated with \n and contain no
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other \n's. The last line may either contain no \n's or a single
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terminated \n. If the lines list does meet this constraint the add
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routine may error or may succeed - but you will be unable to read
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the data back accurately. (Checking the lines have been split
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correctly is expensive and extremely unlikely to catch bugs so it
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is not done at runtime unless check_content is True.)
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:param parent_texts: An optional dictionary containing the opaque
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representations of some or all of the parents of version_id to
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allow delta optimisations. VERY IMPORTANT: the texts must be those
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returned by add_lines or data corruption can be caused.
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:param left_matching_blocks: a hint about which areas are common
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between the text and its left-hand-parent. The format is
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the SequenceMatcher.get_matching_blocks format.
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:param nostore_sha: Raise ExistingContent and do not add the lines to
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the versioned file if the digest of the lines matches this.
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:param random_id: If True a random id has been selected rather than
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an id determined by some deterministic process such as a converter
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from a foreign VCS. When True the backend may choose not to check
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for uniqueness of the resulting key within the versioned file, so
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this should only be done when the result is expected to be unique
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:param check_content: If True, the lines supplied are verified to be
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bytestrings that are correctly formed lines.
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:return: The text sha1, the number of bytes in the text, and an opaque
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representation of the inserted version which can be provided
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back to future add_lines calls in the parent_texts dictionary.
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self._check_write_ok()
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return self._add_lines(version_id, parents, lines, parent_texts,
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left_matching_blocks, nostore_sha, random_id, check_content)
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def _add_lines(self, version_id, parents, lines, parent_texts,
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left_matching_blocks, nostore_sha, random_id, check_content):
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"""Helper to do the class specific add_lines."""
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raise NotImplementedError(self.add_lines)
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def add_lines_with_ghosts(self, version_id, parents, lines,
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parent_texts=None, nostore_sha=None, random_id=False,
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"""Add lines to the versioned file, allowing ghosts to be present.
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This takes the same parameters as add_lines and returns the same.
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self._check_write_ok()
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return self._add_lines_with_ghosts(version_id, parents, lines,
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parent_texts, nostore_sha, random_id, check_content)
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def _add_lines_with_ghosts(self, version_id, parents, lines, parent_texts,
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nostore_sha, random_id, check_content):
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"""Helper to do class specific add_lines_with_ghosts."""
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raise NotImplementedError(self.add_lines_with_ghosts)
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def check(self, progress_bar=None):
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"""Check the versioned file for integrity."""
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raise NotImplementedError(self.check)
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def _check_lines_not_unicode(self, lines):
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"""Check that lines being added to a versioned file are not unicode."""
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if line.__class__ is not str:
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raise errors.BzrBadParameterUnicode("lines")
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def _check_lines_are_lines(self, lines):
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"""Check that the lines really are full lines without inline EOL."""
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if '\n' in line[:-1]:
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raise errors.BzrBadParameterContainsNewline("lines")
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def _check_write_ok(self):
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"""Is the versioned file marked as 'finished' ? Raise if it is."""
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raise errors.OutSideTransaction()
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if self._access_mode != 'w':
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raise errors.ReadOnlyObjectDirtiedError(self)
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def enable_cache(self):
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"""Tell this versioned file that it should cache any data it reads.
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This is advisory, implementations do not have to support caching.
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def clear_cache(self):
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"""Remove any data cached in the versioned file object.
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This only needs to be supported if caches are supported
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def clone_text(self, new_version_id, old_version_id, parents):
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"""Add an identical text to old_version_id as new_version_id.
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Must raise RevisionNotPresent if the old version or any of the
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parents are not present in file history.
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Must raise RevisionAlreadyPresent if the new version is
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already present in file history."""
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self._check_write_ok()
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return self._clone_text(new_version_id, old_version_id, parents)
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def _clone_text(self, new_version_id, old_version_id, parents):
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"""Helper function to do the _clone_text work."""
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raise NotImplementedError(self.clone_text)
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def create_empty(self, name, transport, mode=None):
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"""Create a new versioned file of this exact type.
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:param name: the file name
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:param transport: the transport
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:param mode: optional file mode.
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raise NotImplementedError(self.create_empty)
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def get_format_signature(self):
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"""Get a text description of the data encoding in this file.
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raise NotImplementedError(self.get_format_signature)
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def make_mpdiffs(self, version_ids):
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"""Create multiparent diffs for specified versions."""
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knit_versions = set()
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for version_id in version_ids:
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knit_versions.add(version_id)
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knit_versions.update(self.get_parents(version_id))
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lines = dict(zip(knit_versions,
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self._get_lf_split_line_list(knit_versions)))
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for version_id in version_ids:
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target = lines[version_id]
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parents = [lines[p] for p in self.get_parents(version_id)]
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left_parent_blocks = self._extract_blocks(version_id,
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left_parent_blocks = None
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diffs.append(multiparent.MultiParent.from_lines(target, parents,
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def _extract_blocks(self, version_id, source, target):
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def add_mpdiffs(self, records):
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"""Add mpdiffs to this VersionedFile.
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Records should be iterables of version, parents, expected_sha1,
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mpdiff. mpdiff should be a MultiParent instance.
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# Does this need to call self._check_write_ok()? (IanC 20070919)
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mpvf = multiparent.MultiMemoryVersionedFile()
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for version, parent_ids, expected_sha1, mpdiff in records:
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versions.append(version)
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mpvf.add_diff(mpdiff, version, parent_ids)
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needed_parents = set()
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for version, parent_ids, expected_sha1, mpdiff in records:
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needed_parents.update(p for p in parent_ids
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if not mpvf.has_version(p))
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for parent_id, lines in zip(needed_parents,
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self._get_lf_split_line_list(needed_parents)):
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mpvf.add_version(lines, parent_id, [])
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for (version, parent_ids, expected_sha1, mpdiff), lines in\
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zip(records, mpvf.get_line_list(versions)):
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if len(parent_ids) == 1:
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left_matching_blocks = list(mpdiff.get_matching_blocks(0,
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mpvf.get_diff(parent_ids[0]).num_lines()))
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left_matching_blocks = None
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_, _, version_text = self.add_lines(version, parent_ids, lines,
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vf_parents, left_matching_blocks=left_matching_blocks)
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vf_parents[version] = version_text
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for (version, parent_ids, expected_sha1, mpdiff), sha1 in\
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zip(records, self.get_sha1s(versions)):
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if expected_sha1 != sha1:
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raise errors.VersionedFileInvalidChecksum(version)
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def get_sha1(self, version_id):
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"""Get the stored sha1 sum for the given revision.
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:param version_id: The name of the version to lookup
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raise NotImplementedError(self.get_sha1)
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def get_sha1s(self, version_ids):
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"""Get the stored sha1 sums for the given revisions.
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:param version_ids: The names of the versions to lookup
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:return: a list of sha1s in order according to the version_ids
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raise NotImplementedError(self.get_sha1s)
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def get_suffixes(self):
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"""Return the file suffixes associated with this versioned file."""
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raise NotImplementedError(self.get_suffixes)
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def get_text(self, version_id):
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"""Return version contents as a text string.
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Raises RevisionNotPresent if version is not present in
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return ''.join(self.get_lines(version_id))
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get_string = get_text
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def get_texts(self, version_ids):
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"""Return the texts of listed versions as a list of strings.
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Raises RevisionNotPresent if version is not present in
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return [''.join(self.get_lines(v)) for v in version_ids]
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def get_lines(self, version_id):
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"""Return version contents as a sequence of lines.
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Raises RevisionNotPresent if version is not present in
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raise NotImplementedError(self.get_lines)
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def _get_lf_split_line_list(self, version_ids):
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return [StringIO(t).readlines() for t in self.get_texts(version_ids)]
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def get_ancestry(self, version_ids, topo_sorted=True):
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"""Return a list of all ancestors of given version(s). This
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will not include the null revision.
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This list will not be topologically sorted if topo_sorted=False is
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Must raise RevisionNotPresent if any of the given versions are
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not present in file history."""
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if isinstance(version_ids, basestring):
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version_ids = [version_ids]
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raise NotImplementedError(self.get_ancestry)
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def get_ancestry_with_ghosts(self, version_ids):
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"""Return a list of all ancestors of given version(s). This
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will not include the null revision.
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Must raise RevisionNotPresent if any of the given versions are
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not present in file history.
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Ghosts that are known about will be included in ancestry list,
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but are not explicitly marked.
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raise NotImplementedError(self.get_ancestry_with_ghosts)
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def get_graph(self, version_ids=None):
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"""Return a graph from the versioned file.
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Ghosts are not listed or referenced in the graph.
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:param version_ids: Versions to select.
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None means retrieve all versions.
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if version_ids is None:
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return dict(self.iter_parents(self.versions()))
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pending = set(version_ids)
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this_iteration = pending
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for version, parents in self.iter_parents(this_iteration):
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result[version] = parents
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for parent in parents:
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def get_graph_with_ghosts(self):
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"""Return a graph for the entire versioned file.
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Ghosts are referenced in parents list but are not
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raise NotImplementedError(self.get_graph_with_ghosts)
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def get_parents(self, version_id):
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"""Return version names for parents of a version.
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Must raise RevisionNotPresent if version is not present in
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raise NotImplementedError(self.get_parents)
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def get_parents_with_ghosts(self, version_id):
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"""Return version names for parents of version_id.
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Will raise RevisionNotPresent if version_id is not present
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Ghosts that are known about will be included in the parent list,
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but are not explicitly marked.
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raise NotImplementedError(self.get_parents_with_ghosts)
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def annotate_iter(self, version_id):
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"""Yield list of (version-id, line) pairs for the specified
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Must raise RevisionNotPresent if the given version is
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not present in file history.
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raise NotImplementedError(self.annotate_iter)
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def annotate(self, version_id):
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return list(self.annotate_iter(version_id))
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def join(self, other, pb=None, msg=None, version_ids=None,
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ignore_missing=False):
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"""Integrate versions from other into this versioned file.
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If version_ids is None all versions from other should be
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incorporated into this versioned file.
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Must raise RevisionNotPresent if any of the specified versions
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are not present in the other file's history unless ignore_missing
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is supplied in which case they are silently skipped.
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self._check_write_ok()
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return InterVersionedFile.get(other, self).join(
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def iter_lines_added_or_present_in_versions(self, version_ids=None,
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"""Iterate over the lines in the versioned file from version_ids.
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This may return lines from other versions. Each item the returned
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iterator yields is a tuple of a line and a text version that that line
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is present in (not introduced in).
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Ordering of results is in whatever order is most suitable for the
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underlying storage format.
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If a progress bar is supplied, it may be used to indicate progress.
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The caller is responsible for cleaning up progress bars (because this
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NOTES: Lines are normalised: they will all have \n terminators.
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Lines are returned in arbitrary order.
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:return: An iterator over (line, version_id).
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raise NotImplementedError(self.iter_lines_added_or_present_in_versions)
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def iter_parents(self, version_ids):
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"""Iterate through the parents for many version ids.
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:param version_ids: An iterable yielding version_ids.
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:return: An iterator that yields (version_id, parents). Requested
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version_ids not present in the versioned file are simply skipped.
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The order is undefined, allowing for different optimisations in
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the underlying implementation.
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for version_id in version_ids:
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yield version_id, tuple(self.get_parents(version_id))
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except errors.RevisionNotPresent:
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def transaction_finished(self):
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"""The transaction that this file was opened in has finished.
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This records self.finished = True and should cause all mutating
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def plan_merge(self, ver_a, ver_b):
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"""Return pseudo-annotation indicating how the two versions merge.
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This is computed between versions a and b and their common
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Weave lines present in none of them are skipped entirely.
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killed-base Dead in base revision
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killed-both Killed in each revision
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unchanged Alive in both a and b (possibly created in both)
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ghost-a Killed in a, unborn in b
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ghost-b Killed in b, unborn in a
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irrelevant Not in either revision
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raise NotImplementedError(VersionedFile.plan_merge)
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def weave_merge(self, plan, a_marker=TextMerge.A_MARKER,
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b_marker=TextMerge.B_MARKER):
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return PlanWeaveMerge(plan, a_marker, b_marker).merge_lines()[0]
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class _PlanMergeVersionedFile(object):
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"""A VersionedFile for uncommitted and committed texts.
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It is intended to allow merges to be planned with working tree texts.
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It implements only the small part of the VersionedFile interface used by
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PlanMerge. It falls back to multiple versionedfiles for data not stored in
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_PlanMergeVersionedFile itself.
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def __init__(self, file_id, fallback_versionedfiles=None):
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:param file_id: Used when raising exceptions.
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:param fallback_versionedfiles: If supplied, the set of fallbacks to
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use. Otherwise, _PlanMergeVersionedFile.fallback_versionedfiles
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can be appended to later.
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self._file_id = file_id
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if fallback_versionedfiles is None:
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self.fallback_versionedfiles = []
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self.fallback_versionedfiles = fallback_versionedfiles
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def plan_merge(self, ver_a, ver_b, base=None):
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"""See VersionedFile.plan_merge"""
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from bzrlib.merge import _PlanMerge
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return _PlanMerge(ver_a, ver_b, self).plan_merge()
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old_plan = list(_PlanMerge(ver_a, base, self).plan_merge())
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new_plan = list(_PlanMerge(ver_a, ver_b, self).plan_merge())
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return _PlanMerge._subtract_plans(old_plan, new_plan)
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def plan_lca_merge(self, ver_a, ver_b, base=None):
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from bzrlib.merge import _PlanLCAMerge
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graph = self._get_graph()
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new_plan = _PlanLCAMerge(ver_a, ver_b, self, graph).plan_merge()
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old_plan = _PlanLCAMerge(ver_a, base, self, graph).plan_merge()
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return _PlanLCAMerge._subtract_plans(list(old_plan), list(new_plan))
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def add_lines(self, version_id, parents, lines):
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"""See VersionedFile.add_lines
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Lines are added locally, not fallback versionedfiles. Also, ghosts are
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permitted. Only reserved ids are permitted.
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if not revision.is_reserved_id(version_id):
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raise ValueError('Only reserved ids may be used')
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raise ValueError('Parents may not be None')
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raise ValueError('Lines may not be None')
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self._parents[version_id] = parents
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self._lines[version_id] = lines
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def get_lines(self, version_id):
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"""See VersionedFile.get_ancestry"""
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lines = self._lines.get(version_id)
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if lines is not None:
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for versionedfile in self.fallback_versionedfiles:
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return versionedfile.get_lines(version_id)
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except errors.RevisionNotPresent:
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raise errors.RevisionNotPresent(version_id, self._file_id)
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def get_ancestry(self, version_id, topo_sorted=False):
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"""See VersionedFile.get_ancestry.
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Note that this implementation assumes that if a VersionedFile can
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answer get_ancestry at all, it can give an authoritative answer. In
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fact, ghosts can invalidate this assumption. But it's good enough
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99% of the time, and far cheaper/simpler.
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Also note that the results of this version are never topologically
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sorted, and are a set.
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raise ValueError('This implementation does not provide sorting')
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parents = self._parents.get(version_id)
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for vf in self.fallback_versionedfiles:
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return vf.get_ancestry(version_id, topo_sorted=False)
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except errors.RevisionNotPresent:
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raise errors.RevisionNotPresent(version_id, self._file_id)
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ancestry = set([version_id])
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for parent in parents:
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ancestry.update(self.get_ancestry(parent, topo_sorted=False))
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def get_parents(self, version_id):
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"""See VersionedFile.get_parents"""
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parents = self._parents.get(version_id)
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if parents is not None:
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for versionedfile in self.fallback_versionedfiles:
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return versionedfile.get_parents(version_id)
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except errors.RevisionNotPresent:
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raise errors.RevisionNotPresent(version_id, self._file_id)
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def _get_graph(self):
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from bzrlib.graph import (
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_StackedParentsProvider,
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from bzrlib.repofmt.knitrepo import _KnitParentsProvider
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parent_providers = [DictParentsProvider(self._parents)]
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for vf in self.fallback_versionedfiles:
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parent_providers.append(_KnitParentsProvider(vf))
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return Graph(_StackedParentsProvider(parent_providers))
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class PlanWeaveMerge(TextMerge):
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"""Weave merge that takes a plan as its input.
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This exists so that VersionedFile.plan_merge is implementable.
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Most callers will want to use WeaveMerge instead.
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def __init__(self, plan, a_marker=TextMerge.A_MARKER,
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b_marker=TextMerge.B_MARKER):
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TextMerge.__init__(self, a_marker, b_marker)
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def _merge_struct(self):
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def outstanding_struct():
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if not lines_a and not lines_b:
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elif ch_a and not ch_b:
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elif ch_b and not ch_a:
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elif lines_a == lines_b:
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yield (lines_a, lines_b)
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# We previously considered either 'unchanged' or 'killed-both' lines
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# to be possible places to resynchronize. However, assuming agreement
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# on killed-both lines may be too aggressive. -- mbp 20060324
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for state, line in self.plan:
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if state == 'unchanged':
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# resync and flush queued conflicts changes if any
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for struct in outstanding_struct():
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if state == 'unchanged':
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elif state == 'killed-a':
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elif state == 'killed-b':
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elif state == 'new-a':
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elif state == 'new-b':
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elif state == 'conflicted-a':
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elif state == 'conflicted-b':
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assert state in ('irrelevant', 'ghost-a', 'ghost-b',
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'killed-base', 'killed-both'), state
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for struct in outstanding_struct():
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class WeaveMerge(PlanWeaveMerge):
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"""Weave merge that takes a VersionedFile and two versions as its input."""
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def __init__(self, versionedfile, ver_a, ver_b,
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a_marker=PlanWeaveMerge.A_MARKER, b_marker=PlanWeaveMerge.B_MARKER):
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plan = versionedfile.plan_merge(ver_a, ver_b)
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PlanWeaveMerge.__init__(self, plan, a_marker, b_marker)
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class InterVersionedFile(InterObject):
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"""This class represents operations taking place between two VersionedFiles.
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Its instances have methods like join, and contain
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references to the source and target versionedfiles these operations can be
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Often we will provide convenience methods on 'versionedfile' which carry out
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operations with another versionedfile - they will always forward to
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InterVersionedFile.get(other).method_name(parameters).
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"""The available optimised InterVersionedFile types."""
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def join(self, pb=None, msg=None, version_ids=None, ignore_missing=False):
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"""Integrate versions from self.source into self.target.
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If version_ids is None all versions from source should be
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incorporated into this versioned file.
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Must raise RevisionNotPresent if any of the specified versions
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are not present in the other file's history unless ignore_missing is
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supplied in which case they are silently skipped.
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# - if the target is empty, just add all the versions from
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# source to target, otherwise:
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# - make a temporary versioned file of type target
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# - insert the source content into it one at a time
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if not self.target.versions():
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# Make a new target-format versioned file.
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temp_source = self.target.create_empty("temp", MemoryTransport())
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version_ids = self._get_source_version_ids(version_ids, ignore_missing)
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graph = self.source.get_graph(version_ids)
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order = tsort.topo_sort(graph.items())
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pb = ui.ui_factory.nested_progress_bar()
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# TODO for incremental cross-format work:
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# make a versioned file with the following content:
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# all revisions we have been asked to join
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# all their ancestors that are *not* in target already.
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# the immediate parents of the above two sets, with
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# empty parent lists - these versions are in target already
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# and the incorrect version data will be ignored.
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# TODO: for all ancestors that are present in target already,
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# check them for consistent data, this requires moving sha1 from
751
# TODO: remove parent texts when they are not relevant any more for
752
# memory pressure reduction. RBC 20060313
753
# pb.update('Converting versioned data', 0, len(order))
755
for index, version in enumerate(order):
756
pb.update('Converting versioned data', index, total)
757
_, _, parent_text = target.add_lines(version,
758
self.source.get_parents(version),
759
self.source.get_lines(version),
760
parent_texts=parent_texts)
761
parent_texts[version] = parent_text
763
# this should hit the native code path for target
764
if target is not self.target:
765
return self.target.join(temp_source,
775
def _get_source_version_ids(self, version_ids, ignore_missing):
776
"""Determine the version ids to be used from self.source.
778
:param version_ids: The caller-supplied version ids to check. (None
779
for all). If None is in version_ids, it is stripped.
780
:param ignore_missing: if True, remove missing ids from the version
781
list. If False, raise RevisionNotPresent on
782
a missing version id.
783
:return: A set of version ids.
785
if version_ids is None:
786
# None cannot be in source.versions
787
return set(self.source.versions())
790
return set(self.source.versions()).intersection(set(version_ids))
792
new_version_ids = set()
793
for version in version_ids:
796
if not self.source.has_version(version):
797
raise errors.RevisionNotPresent(version, str(self.source))
799
new_version_ids.add(version)
800
return new_version_ids
added
removed
bzrlib/versionedfile.py
