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

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

--- a/hgext/censor.py	Thu Apr 05 15:18:23 2018 -0700
+++ b/hgext/censor.py	Thu Apr 05 18:22:35 2018 -0700
@@ -32,7 +32,6 @@
 
 from mercurial import (
     error,
-    filelog,
     lock as lockmod,
     registrar,
     revlog,
@@ -106,7 +105,7 @@
         raise error.Abort(
             _('censor does not support revlog version %d') % (flogv,))
 
-    tombstone = filelog.packmeta({"censored": tombstone}, "")
+    tombstone = revlog.packmeta({"censored": tombstone}, "")
 
     crev = fctx.filerev()
 

--- a/hgext/lfs/wrapper.py	Thu Apr 05 15:18:23 2018 -0700
+++ b/hgext/lfs/wrapper.py	Thu Apr 05 18:22:35 2018 -0700
@@ -14,7 +14,6 @@
 
 from mercurial import (
     error,
-    filelog,
     revlog,
     util,
 )
@@ -69,13 +68,13 @@
             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 @@
                        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
 

--- a/mercurial/filelog.py	Thu Apr 05 15:18:23 2018 -0700
+++ b/mercurial/filelog.py	Thu Apr 05 18:22:35 2018 -0700
@@ -7,7 +7,6 @@
 
 from __future__ import absolute_import
 
-import re
 import struct
 
 from .thirdparty.zope import (
@@ -20,27 +19,8 @@
     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 @@
 
     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

--- a/mercurial/revlog.py	Thu Apr 05 15:18:23 2018 -0700
+++ b/mercurial/revlog.py	Thu Apr 05 18:22:35 2018 -0700
@@ -19,6 +19,7 @@
 import hashlib
 import heapq
 import os
+import re
 import struct
 import zlib
 
@@ -97,6 +98,25 @@
     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.
 

--- a/tests/simplestorerepo.py	Thu Apr 05 15:18:23 2018 -0700
+++ b/tests/simplestorerepo.py	Thu Apr 05 18:22:35 2018 -0700
@@ -32,7 +32,6 @@
     bundlerepo,
     error,
     extensions,
-    filelog,
     localrepo,
     mdiff,
     pycompat,
@@ -326,7 +325,7 @@
             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 @@
 
     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)