hooks: use try/except/finally

mercurial/hook.py

@@ -1,213 +1,211 b''
 # hook.py - hook support for mercurial
 #
 # Copyright 2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from i18n import _
 import os, sys, time
 import extensions, util, demandimport, error
 
 def _pythonhook(ui, repo, name, hname, funcname, args, throw):
     '''call python hook. hook is callable object, looked up as
     name in python module. if callable returns "true", hook
     fails, else passes. if hook raises exception, treated as
     hook failure. exception propagates if throw is "true".
 
     reason for "true" meaning "hook failed" is so that
     unmodified commands (e.g. mercurial.commands.update) can
     be run as hooks without wrappers to convert return values.'''
 
     if callable(funcname):
         obj = funcname
         funcname = obj.__module__ + "." + obj.__name__
     else:
         d = funcname.rfind('.')
         if d == -1:
             raise util.Abort(_('%s hook is invalid ("%s" not in '
                                'a module)') % (hname, funcname))
         modname = funcname[:d]
         oldpaths = sys.path
         if util.mainfrozen():
             # binary installs require sys.path manipulation
             modpath, modfile = os.path.split(modname)
             if modpath and modfile:
                 sys.path = sys.path[:] + [modpath]
                 modname = modfile
         demandimportenabled = demandimport.isenabled()
         if demandimportenabled:
             demandimport.disable()
         try:
+            obj = __import__(modname)
+        except ImportError:
+            e1 = sys.exc_type, sys.exc_value, sys.exc_traceback
             try:
-                obj = __import__(modname)
+                # extensions are loaded with hgext_ prefix
+                obj = __import__("hgext_%s" % modname)
             except ImportError:
-                e1 = sys.exc_type, sys.exc_value, sys.exc_traceback
-                try:
-                    # extensions are loaded with hgext_ prefix
-                    obj = __import__("hgext_%s" % modname)
-                except ImportError:
-                    e2 = sys.exc_type, sys.exc_value, sys.exc_traceback
-                    if ui.tracebackflag:
-                        ui.warn(_('exception from first failed import '
-                                  'attempt:\n'))
-                    ui.traceback(e1)
-                    if ui.tracebackflag:
-                        ui.warn(_('exception from second failed import '
-                                  'attempt:\n'))
-                    ui.traceback(e2)
-                    raise util.Abort(_('%s hook is invalid '
-                                       '(import of "%s" failed)') %
-                                     (hname, modname))
+                e2 = sys.exc_type, sys.exc_value, sys.exc_traceback
+                if ui.tracebackflag:
+                    ui.warn(_('exception from first failed import '
+                              'attempt:\n'))
+                ui.traceback(e1)
+                if ui.tracebackflag:
+                    ui.warn(_('exception from second failed import '
+                              'attempt:\n'))
+                ui.traceback(e2)
+                raise util.Abort(_('%s hook is invalid '
+                                   '(import of "%s" failed)') %
+                                 (hname, modname))
         finally:
             if demandimportenabled:
                 demandimport.enable()
         sys.path = oldpaths
         try:
             for p in funcname.split('.')[1:]:
                 obj = getattr(obj, p)
         except AttributeError:
             raise util.Abort(_('%s hook is invalid '
                                '("%s" is not defined)') %
                              (hname, funcname))
         if not callable(obj):
             raise util.Abort(_('%s hook is invalid '
                                '("%s" is not callable)') %
                              (hname, funcname))
 
     ui.note(_("calling hook %s: %s\n") % (hname, funcname))
     starttime = time.time()
 
     try:
-        try:
-            # redirect IO descriptors to the ui descriptors so hooks
-            # that write directly to these don't mess up the command
-            # protocol when running through the command server
-            old = sys.stdout, sys.stderr, sys.stdin
-            sys.stdout, sys.stderr, sys.stdin = ui.fout, ui.ferr, ui.fin
+        # redirect IO descriptors to the ui descriptors so hooks
+        # that write directly to these don't mess up the command
+        # protocol when running through the command server
+        old = sys.stdout, sys.stderr, sys.stdin
+        sys.stdout, sys.stderr, sys.stdin = ui.fout, ui.ferr, ui.fin
 
-            r = obj(ui=ui, repo=repo, hooktype=name, **args)
-        except KeyboardInterrupt:
+        r = obj(ui=ui, repo=repo, hooktype=name, **args)
+    except KeyboardInterrupt:
+        raise
+    except Exception, exc:
+        if isinstance(exc, util.Abort):
+            ui.warn(_('error: %s hook failed: %s\n') %
+                         (hname, exc.args[0]))
+        else:
+            ui.warn(_('error: %s hook raised an exception: '
+                           '%s\n') % (hname, exc))
+        if throw:
             raise
-        except Exception, exc:
-            if isinstance(exc, util.Abort):
-                ui.warn(_('error: %s hook failed: %s\n') %
-                             (hname, exc.args[0]))
-            else:
-                ui.warn(_('error: %s hook raised an exception: '
-                               '%s\n') % (hname, exc))
-            if throw:
-                raise
-            ui.traceback()
-            return True
+        ui.traceback()
+        return True
     finally:
         sys.stdout, sys.stderr, sys.stdin = old
         duration = time.time() - starttime
         ui.log('pythonhook', 'pythonhook-%s: %s finished in %0.2f seconds\n',
                name, funcname, duration)
     if r:
         if throw:
             raise error.HookAbort(_('%s hook failed') % hname)
         ui.warn(_('warning: %s hook failed\n') % hname)
     return r
 
 def _exthook(ui, repo, name, cmd, args, throw):
     ui.note(_("running hook %s: %s\n") % (name, cmd))
 
     starttime = time.time()
     env = {}
     for k, v in args.iteritems():
         if callable(v):
             v = v()
         if isinstance(v, dict):
             # make the dictionary element order stable across Python
             # implementations
             v = ('{' +
                  ', '.join('%r: %r' % i for i in sorted(v.iteritems())) +
                  '}')
         env['HG_' + k.upper()] = v
 
     if repo:
         cwd = repo.root
     else:
         cwd = os.getcwd()
     r = ui.system(cmd, environ=env, cwd=cwd)
 
     duration = time.time() - starttime
     ui.log('exthook', 'exthook-%s: %s finished in %0.2f seconds\n',
            name, cmd, duration)
     if r:
         desc, r = util.explainexit(r)
         if throw:
             raise error.HookAbort(_('%s hook %s') % (name, desc))
         ui.warn(_('warning: %s hook %s\n') % (name, desc))
     return r
 
 def _allhooks(ui):
     hooks = []
     for name, cmd in ui.configitems('hooks'):
         if not name.startswith('priority'):
             priority = ui.configint('hooks', 'priority.%s' % name, 0)
             hooks.append((-priority, len(hooks), name, cmd))
     return [(k, v) for p, o, k, v in sorted(hooks)]
 
 _redirect = False
 def redirect(state):
     global _redirect
     _redirect = state
 
 def hook(ui, repo, name, throw=False, **args):
     if not ui.callhooks:
         return False
 
     r = False
     oldstdout = -1
 
     try:
         for hname, cmd in _allhooks(ui):
             if hname.split('.')[0] != name or not cmd:
                 continue
 
             if oldstdout == -1 and _redirect:
                 try:
                     stdoutno = sys.__stdout__.fileno()
                     stderrno = sys.__stderr__.fileno()
                     # temporarily redirect stdout to stderr, if possible
                     if stdoutno >= 0 and stderrno >= 0:
                         sys.__stdout__.flush()
                         oldstdout = os.dup(stdoutno)
                         os.dup2(stderrno, stdoutno)
                 except (OSError, AttributeError):
                     # files seem to be bogus, give up on redirecting (WSGI, etc)
                     pass
 
             if callable(cmd):
                 r = _pythonhook(ui, repo, name, hname, cmd, args, throw) or r
             elif cmd.startswith('python:'):
                 if cmd.count(':') >= 2:
                     path, cmd = cmd[7:].rsplit(':', 1)
                     path = util.expandpath(path)
                     if repo:
                         path = os.path.join(repo.root, path)
                     try:
                         mod = extensions.loadpath(path, 'hghook.%s' % hname)
                     except Exception:
                         ui.write(_("loading %s hook failed:\n") % hname)
                         raise
                     hookfn = getattr(mod, cmd)
                 else:
                     hookfn = cmd[7:].strip()
                 r = _pythonhook(ui, repo, name, hname, hookfn, args, throw) or r
             else:
                 r = _exthook(ui, repo, hname, cmd, args, throw) or r
 
             # The stderr is fully buffered on Windows when connected to a pipe.
             # A forcible flush is required to make small stderr data in the
             # remote side available to the client immediately.
             sys.stderr.flush()
     finally:
         if _redirect and oldstdout >= 0:
             os.dup2(oldstdout, stdoutno)
             os.close(oldstdout)
 
     return r