[PATCH 1 of 5] streamclone: extract code for reading header fields

[Gregory Szorc]

# HG changeset patch
# User Gregory Szorc <gregory.szorc at gmail.com>
# Date 1452840534 28800
#      Thu Jan 14 22:48:54 2016 -0800
# Node ID 2292827fab6b8c367617c14b4a509b79654a75f0
# Parent  63116d47cc3fd179c90b117397cc26341a381edb
streamclone: extract code for reading header fields

So it can be called from another consumer in a future patch.

diff --git a/mercurial/streamclone.py b/mercurial/streamclone.py
--- a/mercurial/streamclone.py
+++ b/mercurial/streamclone.py
@@ -337,40 +337,45 @@ def consumev1(repo, fp, filecount, bytec
             elapsed = 0.001
         repo.ui.progress(_('clone'), None)
         repo.ui.status(_('transferred %s in %.1f seconds (%s/sec)\n') %
                        (util.bytecount(bytecount), elapsed,
                         util.bytecount(bytecount / elapsed)))
     finally:
         lock.release()
 
-def applybundlev1(repo, fp):
-    """Apply the content from a stream clone bundle version 1.
-
-    We assume the 4 byte header has been read and validated and the file handle
-    is at the 2 byte compression identifier.
-    """
-    if len(repo):
-        raise error.Abort(_('cannot apply stream clone bundle on non-empty '
-                            'repo'))
-
+def readbundle1header(fp):
     compression = fp.read(2)
     if compression != 'UN':
         raise error.Abort(_('only uncompressed stream clone bundles are '
             'supported; got %s') % compression)
 
     filecount, bytecount = struct.unpack('>QQ', fp.read(16))
     requireslen = struct.unpack('>H', fp.read(2))[0]
     requires = fp.read(requireslen)
 
     if not requires.endswith('\0'):
         raise error.Abort(_('malformed stream clone bundle: '
                             'requirements not properly encoded'))
 
     requirements = set(requires.rstrip('\0').split(','))
+
+    return filecount, bytecount, requirements
+
+def applybundlev1(repo, fp):
+    """Apply the content from a stream clone bundle version 1.
+
+    We assume the 4 byte header has been read and validated and the file handle
+    is at the 2 byte compression identifier.
+    """
+    if len(repo):
+        raise error.Abort(_('cannot apply stream clone bundle on non-empty '
+                            'repo'))
+
+    filecount, bytecount, requirements = readbundle1header(fp)
     missingreqs = requirements - repo.supportedformats
     if missingreqs:
         raise error.Abort(_('unable to apply stream clone: '
                             'unsupported format: %s') %
                             ', '.join(sorted(missingreqs)))
 
     consumev1(repo, fp, filecount, bytecount)