Mercurial > public > mercurial-scm > hg

annotate mercurial/dirstateutils/docket.py @ 47674:ff97e793ed36

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
dirstate-v2: Introduce a docket file .hg/dirstate now only contains some metadata to point to a separate data file named .hg/dirstate.{}.d with a random hexadecimal identifier. For now every update creates a new data file and removes the old one, but later we?ll (usually) append to an existing file. Separating into two files allows doing the "write to a temporary file then atomically rename into destination" dance with only a small docket file, without always rewriting a lot of data. Differential Revision: https://phab.mercurial-scm.org/D11088
author Simon Sapin <simon.sapin@octobus.net>
date Thu, 08 Jul 2021 12:18:21 +0200
parents
children 78f7f0d490ee
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
47674
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
1 # dirstatedocket.py - docket file for dirstate-v2
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
2 #
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
3 # Copyright Mercurial Contributors
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
4 #
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
5 # This software may be used and distributed according to the terms of the
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
6 # GNU General Public License version 2 or any later version.
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
7
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
8 from __future__ import absolute_import
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
9
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
10 import struct
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
11
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
12 from ..revlogutils import docket as docket_mod
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
13
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
14
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
15 V2_FORMAT_MARKER = b"dirstate-v2\n"
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
16
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
17 # * 12 bytes: format marker
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
18 # * 32 bytes: node ID of the working directory's first parent
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
19 # * 32 bytes: node ID of the working directory's second parent
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
20 # * 4 bytes: big-endian used size of the data file
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
21 # * 1 byte: length of the data file's UUID
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
22 # * variable: data file's UUID
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
23 #
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
24 # Node IDs are null-padded if shorter than 32 bytes.
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
25 # A data file shorter than the specified used size is corrupted (truncated)
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
26 HEADER = struct.Struct(">{}s32s32sLB".format(len(V2_FORMAT_MARKER)))
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
27
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
28
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
29 class DirstateDocket(object):
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
30 data_filename_pattern = b'dirstate.%s.d'
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
31
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
32 def __init__(self, parents, data_size, uuid):
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
33 self.parents = parents
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
34 self.data_size = data_size
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
35 self.uuid = uuid
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
36
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
37 @classmethod
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
38 def with_new_uuid(cls, parents, data):
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
39 return cls(parents, data, docket_mod.make_uid())
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
40
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
41 @classmethod
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
42 def parse(cls, data, nodeconstants):
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
43 if not data:
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
44 parents = (nodeconstants.nullid, nodeconstants.nullid)
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
45 return cls(parents, 0, None)
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
46 marker, p1, p2, data_size, uuid_size = HEADER.unpack_from(data)
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
47 if marker != V2_FORMAT_MARKER:
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
48 raise ValueError("expected dirstate-v2 marker")
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
49 uuid = data[HEADER.size : HEADER.size + uuid_size]
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
50 p1 = p1[: nodeconstants.nodelen]
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
51 p2 = p2[: nodeconstants.nodelen]
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
52 return cls((p1, p2), data_size, uuid)
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
53
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
54 def serialize(self):
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
55 p1, p2 = self.parents
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
56 header = HEADER.pack(
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
57 V2_FORMAT_MARKER, p1, p2, self.data_size, len(self.uuid)
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
58 )
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
59 return header + self.uuid
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
60
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
61 def data_filename(self):
ff97e793ed36 dirstate-v2: Introduce a docket file
Simon Sapin <simon.sapin@octobus.net>
parents:
diff changeset
62 return self.data_filename_pattern % self.uuid