Mercurial > hg
annotate mercurial/utils/storageutil.py @ 39878:3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Parsing and writing of revision text metadata is likely identical
across storage backends. Let's move the code out of revlog so we
don't need to import the revlog module in order to use it.
Differential Revision: https://phab.mercurial-scm.org/D4754
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Mon, 24 Sep 2018 14:31:31 -0700 |
parents | f8eb71f9e3bd |
children | d269ddbf54f0 |
rev | line source |
---|---|
39877
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
1 # storageutil.py - Storage functionality agnostic of backend implementation. |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
2 # |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
3 # Copyright 2018 Gregory Szorc <gregory.szorc@gmail.com> |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
4 # |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
5 # This software may be used and distributed according to the terms of the |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
6 # GNU General Public License version 2 or any later version. |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
7 |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
8 from __future__ import absolute_import |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
9 |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
10 import hashlib |
39878
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
11 import re |
39877
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
12 |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
13 from ..node import ( |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
14 nullid, |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
15 ) |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
16 |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
17 _nullhash = hashlib.sha1(nullid) |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
18 |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
19 def hashrevisionsha1(text, p1, p2): |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
20 """Compute the SHA-1 for revision data and its parents. |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
21 |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
22 This hash combines both the current file contents and its history |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
23 in a manner that makes it easy to distinguish nodes with the same |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
24 content in the revision graph. |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
25 """ |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
26 # As of now, if one of the parent node is null, p2 is null |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
27 if p2 == nullid: |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
28 # deep copy of a hash is faster than creating one |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
29 s = _nullhash.copy() |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
30 s.update(p1) |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
31 else: |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
32 # none of the parent nodes are nullid |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
33 if p1 < p2: |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
34 a = p1 |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
35 b = p2 |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
36 else: |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
37 a = p2 |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
38 b = p1 |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
39 s = hashlib.sha1(a) |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
40 s.update(b) |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
41 s.update(text) |
f8eb71f9e3bd
storageutil: new module for storage primitives (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
diff
changeset
|
42 return s.digest() |
39878
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
43 |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
44 METADATA_RE = re.compile(b'\x01\n') |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
45 |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
46 def parsemeta(text): |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
47 """Parse metadata header from revision data. |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
48 |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
49 Returns a 2-tuple of (metadata, offset), where both can be None if there |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
50 is no metadata. |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
51 """ |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
52 # text can be buffer, so we can't use .startswith or .index |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
53 if text[:2] != b'\x01\n': |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
54 return None, None |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
55 s = METADATA_RE.search(text, 2).start() |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
56 mtext = text[2:s] |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
57 meta = {} |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
58 for l in mtext.splitlines(): |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
59 k, v = l.split(b': ', 1) |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
60 meta[k] = v |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
61 return meta, s + 2 |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
62 |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
63 def packmeta(meta, text): |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
64 """Add metadata to fulltext to produce revision text.""" |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
65 keys = sorted(meta) |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
66 metatext = b''.join(b'%s: %s\n' % (k, meta[k]) for k in keys) |
3e896b51aa5d
storageutil: move metadata parsing and packing from revlog (API)
Gregory Szorc <gregory.szorc@gmail.com>
parents:
39877
diff
changeset
|
67 return b'\x01\n%s\x01\n%s' % (metatext, text) |