revlog: move parsemeta() and packmeta() from filelog (API)

filelog.parsemeta() and filelog.packmeta() are used to decode
and encode metadata for file copies and censor.

An upcoming commit will move the core logic for censoring revlogs
into revlog.py. This would create a cycle between revlog.py and
filelog.py. So we move these metadata functions to revlog.py.

.. api::

   filelog.parsemeta() and filelog.packmeta() have been moved to
   the revlog module.

Differential Revision: https://phab.mercurial-scm.org/D3150

hgext/censor.py

@@ -32,7 +32,6 b' from mercurial.node import short'
 
 from mercurial import (
     error,
-    filelog,
     lock as lockmod,
     registrar,
     revlog,
@@ -106,7 +105,7 b" def _docensor(ui, repo, path, rev='', to"
         raise error.Abort(
             _('censor does not support revlog version %d') % (flogv,))
 
-    tombstone = filelog.packmeta({"censored": tombstone}, "")
+    tombstone = revlog.packmeta({"censored": tombstone}, "")
 
     crev = fctx.filerev()
 

hgext/lfs/wrapper.py

@@ -14,7 +14,6 b' from mercurial.node import bin, hex, nul'
 
 from mercurial import (
     error,
-    filelog,
     revlog,
     util,
 )
@@ -69,13 +68,13 b' def readfromstore(self, text):'
             name = k[len('x-hg-'):]
             hgmeta[name] = p[k]
     if hgmeta or text.startswith('\1\n'):
-        text = filelog.packmeta(hgmeta, text)
+        text = revlog.packmeta(hgmeta, text)
 
     return (text, True)
 
 def writetostore(self, text):
     # hg filelog metadata (includes rename, etc)
-    hgmeta, offset = filelog.parsemeta(text)
+    hgmeta, offset = revlog.parsemeta(text)
     if offset and offset > 0:
         # lfs blob does not contain hg filelog metadata
         text = text[offset:]
@@ -121,7 +120,7 b' def filelogaddrevision(orig, self, text,'
                        flags=revlog.REVIDX_DEFAULT_FLAGS, **kwds):
     textlen = len(text)
     # exclude hg rename meta from file size
-    meta, offset = filelog.parsemeta(text)
+    meta, offset = revlog.parsemeta(text)
     if offset:
         textlen -= offset
 

mercurial/filelog.py

@@ -7,7 +7,6 b''
 
 from __future__ import absolute_import
 
-import re
 import struct
 
 from .thirdparty.zope import (
@@ -20,27 +19,8 b' from . import ('
     revlog,
 )
 
-_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 = revlog.parsemeta(text)
     return m and "censored" in m
 
 @zi.implementer(repository.ifilestorage)
@@ -60,14 +40,14 b' class filelog(revlog.revlog):'
 
     def add(self, text, meta, transaction, link, p1=None, p2=None):
         if meta or text.startswith('\1\n'):
-            text = packmeta(meta, text)
+            text = revlog.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 = parsemeta(t)[0]
+        m = revlog.parsemeta(t)[0]
         if m and "copy" in m:
             return (m["copy"], revlog.bin(m["copyrev"]))
         return False

mercurial/revlog.py

@@ -19,6 +19,7 b' import errno'
 import hashlib
 import heapq
 import os
+import re
 import struct
 import zlib
 
@@ -97,6 +98,25 b' ProgrammingError = error.ProgrammingErro'
     REVIDX_ISCENSORED: None,
 }
 
+_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 addflagprocessor(flag, processor):
     """Register a flag processor on a revision data flag.
 

tests/simplestorerepo.py

@@ -32,7 +32,6 b' from mercurial import ('
     bundlerepo,
     error,
     extensions,
-    filelog,
     localrepo,
     mdiff,
     pycompat,
@@ -326,7 +325,7 b' class filestorage(object):'
             return False
 
         fulltext = self.revision(node)
-        m = filelog.parsemeta(fulltext)[0]
+        m = revlog.parsemeta(fulltext)[0]
 
         if m and 'copy' in m:
             return m['copy'], bin(m['copyrev'])
@@ -415,7 +414,7 b' class filestorage(object):'
 
     def add(self, text, meta, transaction, linkrev, p1, p2):
         if meta or text.startswith(b'\1\n'):
-            text = filelog.packmeta(meta, text)
+            text = revlog.packmeta(meta, text)
 
         return self.addrevision(text, transaction, linkrev, p1, p2)