changeset 28262:53dc4aada2d9

chgserver: add utilities to calculate confighash confighash is the hash of sensitive config items like [extensions], and sensitive environment variables like HG*, LD_*, etc. The config items can come from global, user, repo config, and command line flags. For chgserver, it is designed that once confighash changes, the server is not qualified to serve its client and should redirect the client to a new server. The server does not need to exit in this case, since it can still be valid (have a matched confighash) to serve other chg clients.
author Jun Wu <quark@fb.com>
date Fri, 26 Feb 2016 14:50:04 +0000
parents 2ab59ac06b76
children 59509c6724c7
files hgext/chgserver.py
diffstat 1 files changed, 39 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/hgext/chgserver.py	Fri Feb 26 14:13:12 2016 +0000
+++ b/hgext/chgserver.py	Fri Feb 26 14:50:04 2016 +0000
@@ -58,6 +58,45 @@
 
 _log = commandserver.log
 
+def _hashlist(items):
+    """return sha1 hexdigest for a list"""
+    return util.sha1(str(items)).hexdigest()
+
+# sensitive config sections affecting confighash
+_configsections = ['extensions']
+
+# sensitive environment variables affecting confighash
+_envre = re.compile(r'''\A(?:
+                    CHGHG
+                    |HG.*
+                    |LANG(?:UAGE)?
+                    |LC_.*
+                    |LD_.*
+                    |PATH
+                    |PYTHON.*
+                    |TERM(?:INFO)?
+                    |TZ
+                    )\Z''', re.X)
+
+def _confighash(ui):
+    """return a quick hash for detecting config/env changes
+
+    confighash is the hash of sensitive config items and environment variables.
+
+    for chgserver, it is designed that once confighash changes, the server is
+    not qualified to serve its client and should redirect the client to a new
+    server. different from mtimehash, confighash change will not mark the
+    server outdated and exit since the user can have different configs at the
+    same time.
+    """
+    sectionitems = []
+    for section in _configsections:
+        sectionitems.append(ui.configitems(section))
+    sectionhash = _hashlist(sectionitems)
+    envitems = [(k, v) for k, v in os.environ.iteritems() if _envre.match(k)]
+    envhash = _hashlist(sorted(envitems))
+    return sectionhash[:6] + envhash[:6]
+
 # copied from hgext/pager.py:uisetup()
 def _setuppagercmd(ui, options, cmd):
     if not ui.formatted():