D4754: storageutil: move metadata parsing and packing from revlog (API)

indygreg (Gregory Szorc) phabricator at mercurial-scm.org
Wed Sep 26 18:30:11 UTC 2018


indygreg created this revision.
Herald added a subscriber: mercurial-devel.
Herald added a reviewer: hg-reviewers.

REVISION SUMMARY
  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.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D4754

AFFECTED FILES
  hgext/lfs/wrapper.py
  mercurial/filelog.py
  mercurial/revlog.py
  mercurial/testing/storage.py
  mercurial/utils/storageutil.py
  tests/simplestorerepo.py

CHANGE DETAILS

diff --git a/tests/simplestorerepo.py b/tests/simplestorerepo.py
--- a/tests/simplestorerepo.py
+++ b/tests/simplestorerepo.py
@@ -326,7 +326,7 @@
             return False
 
         fulltext = self.revision(node)
-        m = revlog.parsemeta(fulltext)[0]
+        m = storageutil.parsemeta(fulltext)[0]
 
         if m and 'copy' in m:
             return m['copy'], bin(m['copyrev'])
@@ -411,7 +411,7 @@
 
     def add(self, text, meta, transaction, linkrev, p1, p2):
         if meta or text.startswith(b'\1\n'):
-            text = revlog.packmeta(meta, text)
+            text = storageutil.packmeta(meta, text)
 
         return self.addrevision(text, transaction, linkrev, p1, p2)
 
diff --git a/mercurial/utils/storageutil.py b/mercurial/utils/storageutil.py
--- a/mercurial/utils/storageutil.py
+++ b/mercurial/utils/storageutil.py
@@ -8,6 +8,7 @@
 from __future__ import absolute_import
 
 import hashlib
+import re
 
 from ..node import (
     nullid,
@@ -39,3 +40,28 @@
         s.update(b)
     s.update(text)
     return s.digest()
+
+METADATA_RE = re.compile(b'\x01\n')
+
+def parsemeta(text):
+    """Parse metadata header from revision data.
+
+    Returns a 2-tuple of (metadata, offset), where both can be None if there
+    is no metadata.
+    """
+    # text can be buffer, so we can't use .startswith or .index
+    if text[:2] != b'\x01\n':
+        return None, None
+    s = METADATA_RE.search(text, 2).start()
+    mtext = text[2:s]
+    meta = {}
+    for l in mtext.splitlines():
+        k, v = l.split(b': ', 1)
+        meta[k] = v
+    return meta, s + 2
+
+def packmeta(meta, text):
+    """Add metadata to fulltext to produce revision text."""
+    keys = sorted(meta)
+    metatext = b''.join(b'%s: %s\n' % (k, meta[k]) for k in keys)
+    return b'\x01\n%s\x01\n%s' % (metatext, text)
diff --git a/mercurial/testing/storage.py b/mercurial/testing/storage.py
--- a/mercurial/testing/storage.py
+++ b/mercurial/testing/storage.py
@@ -19,6 +19,9 @@
     mdiff,
     revlog,
 )
+from ..utils import (
+    storageutil,
+)
 
 class basetestcase(unittest.TestCase):
     if not getattr(unittest.TestCase, r'assertRaisesRegex', False):
@@ -880,7 +883,7 @@
     def testcensored(self):
         f = self._makefilefn()
 
-        stored1 = revlog.packmeta({
+        stored1 = storageutil.packmeta({
             b'censored': b'tombstone',
         }, b'')
 
diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -17,7 +17,6 @@
 import contextlib
 import errno
 import os
-import re
 import struct
 import zlib
 
@@ -127,27 +126,8 @@
     ellipsisrawprocessor,
 )
 
-_mdre = re.compile('\1\n')
-def parsemeta(text):
-    """return (metadatadict, metadatasize)"""
-    # text can be buffer, so we can't use .startswith or .index
-    if text[:2] != '\1\n':
-        return None, None
-    s = _mdre.search(text, 2).start()
-    mtext = text[2:s]
-    meta = {}
-    for l in mtext.splitlines():
-        k, v = l.split(": ", 1)
-        meta[k] = v
-    return meta, (s + 2)
-
-def packmeta(meta, text):
-    keys = sorted(meta)
-    metatext = "".join("%s: %s\n" % (k, meta[k]) for k in keys)
-    return "\1\n%s\1\n%s" % (metatext, text)
-
 def _censoredtext(text):
-    m, offs = parsemeta(text)
+    m, offs = storageutil.parsemeta(text)
     return m and "censored" in m
 
 def addflagprocessor(flag, processor):
@@ -2516,7 +2496,7 @@
                                     self.version)
 
         rev = self.rev(node)
-        tombstone = packmeta({b'censored': tombstone}, b'')
+        tombstone = storageutil.packmeta({b'censored': tombstone}, b'')
 
         if len(tombstone) > self.rawsize(rev):
             raise error.Abort(_('censor tombstone must be no longer than '
diff --git a/mercurial/filelog.py b/mercurial/filelog.py
--- a/mercurial/filelog.py
+++ b/mercurial/filelog.py
@@ -14,6 +14,7 @@
 )
 from .utils import (
     interfaceutil,
+    storageutil,
 )
 
 @interfaceutil.implementer(repository.ifilestorage)
@@ -120,14 +121,14 @@
 
     def add(self, text, meta, transaction, link, p1=None, p2=None):
         if meta or text.startswith('\1\n'):
-            text = revlog.packmeta(meta, text)
+            text = storageutil.packmeta(meta, text)
         return self.addrevision(text, transaction, link, p1, p2)
 
     def renamed(self, node):
         if self.parents(node)[0] != revlog.nullid:
             return False
         t = self.revision(node)
-        m = revlog.parsemeta(t)[0]
+        m = storageutil.parsemeta(t)[0]
         # copy and copyrev occur in pairs. In rare cases due to bugs,
         # one can occur without the other.
         if m and "copy" in m and "copyrev" in m:
diff --git a/hgext/lfs/wrapper.py b/hgext/lfs/wrapper.py
--- a/hgext/lfs/wrapper.py
+++ b/hgext/lfs/wrapper.py
@@ -20,6 +20,7 @@
 )
 
 from mercurial.utils import (
+    storageutil,
     stringutil,
 )
 
@@ -76,13 +77,13 @@
             name = k[len('x-hg-'):]
             hgmeta[name] = p[k]
     if hgmeta or text.startswith('\1\n'):
-        text = revlog.packmeta(hgmeta, text)
+        text = storageutil.packmeta(hgmeta, text)
 
     return (text, True)
 
 def writetostore(self, text):
     # hg filelog metadata (includes rename, etc)
-    hgmeta, offset = revlog.parsemeta(text)
+    hgmeta, offset = storageutil.parsemeta(text)
     if offset and offset > 0:
         # lfs blob does not contain hg filelog metadata
         text = text[offset:]
@@ -132,7 +133,7 @@
     if lfstrack:
         textlen = len(text)
         # exclude hg rename meta from file size
-        meta, offset = revlog.parsemeta(text)
+        meta, offset = storageutil.parsemeta(text)
         if offset:
             textlen -= offset
 



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