From eee7283e896c65fbd86d5449886515dec6b7449c Mon Sep 17 00:00:00 2001
From: Catalin Marinas <catalin.marinas@gmail.com>
Date: Fri, 17 Nov 2006 22:20:40 +0000
Subject: [PATCH] Only read the config files when running a command

This reduces the time to display the help by about 12ms (on my PC).

Signed-off-by: Catalin Marinas <catalin.marinas@gmail.com>
---
 stgit/config.py          | 71 ++++++++++++++++++++++++++++++------------------
 stgit/gitmergeonefile.py | 10 ++-----
 stgit/main.py            |  6 +++-
 3 files changed, 52 insertions(+), 35 deletions(-)

diff --git a/stgit/config.py b/stgit/config.py
index a2e29bb..6679668 100644
--- a/stgit/config.py
+++ b/stgit/config.py
@@ -25,33 +25,50 @@ from stgit import basedir
 
 config = ConfigParser.RawConfigParser()
 
-# Set the defaults
-config.add_section('stgit')
-config.set('stgit', 'autoresolved', 'no')
-config.set('stgit', 'smtpserver', 'localhost:25')
-config.set('stgit', 'smtpdelay', '5')
-config.set('stgit', 'pullcmd', 'git-pull')
-config.set('stgit', 'merger',
-           'diff3 -L current -L ancestor -L patched -m -E ' \
-           '"%(branch1)s" "%(ancestor)s" "%(branch2)s" > "%(output)s"')
-config.set('stgit', 'keeporig', 'yes')
-config.set('stgit', 'keepoptimized', 'no')
-config.set('stgit', 'extensions', '.ancestor .current .patched')
-
-# Read the configuration files (if any) and override the default settings
-config.read('/etc/stgitrc')
-config.read(os.path.expanduser('~/.stgitrc'))
-config.read(os.path.join(basedir.get(), 'stgitrc'))
-
-# Set the PAGER environment to the config value (if any)
-if config.has_option('stgit', 'pager'):
-    os.environ['PAGER'] = config.get('stgit', 'pager')
-
-# [gitmergeonefile] section is deprecated. In case it exists copy the
-# options/values to the [stgit] one
-if config.has_section('gitmergeonefile'):
-    for option, value in config.items('gitmergeonefile'):
-        config.set('stgit', option, value)
+def config_setup():
+    global config
+
+    # Set the defaults
+    config.add_section('stgit')
+    config.set('stgit', 'autoresolved', 'no')
+    config.set('stgit', 'smtpserver', 'localhost:25')
+    config.set('stgit', 'smtpdelay', '5')
+    config.set('stgit', 'pullcmd', 'git-pull')
+    config.set('stgit', 'merger',
+               'diff3 -L current -L ancestor -L patched -m -E ' \
+               '"%(branch1)s" "%(ancestor)s" "%(branch2)s" > "%(output)s"')
+    config.set('stgit', 'keeporig', 'yes')
+    config.set('stgit', 'keepoptimized', 'no')
+    config.set('stgit', 'extensions', '.ancestor .current .patched')
+
+    # Read the configuration files (if any) and override the default settings
+    config.read('/etc/stgitrc')
+    config.read(os.path.expanduser('~/.stgitrc'))
+    config.read(os.path.join(basedir.get(), 'stgitrc'))
+
+    # Set the PAGER environment to the config value (if any)
+    if config.has_option('stgit', 'pager'):
+        os.environ['PAGER'] = config.get('stgit', 'pager')
+
+    # [gitmergeonefile] section is deprecated. In case it exists copy the
+    # options/values to the [stgit] one
+    if config.has_section('gitmergeonefile'):
+        for option, value in config.items('gitmergeonefile'):
+            config.set('stgit', option, value)
+
+
+class ConfigOption:
+    """Delayed cached reading of a configuration option.
+    """
+    def __init__(self, section, option):
+        self.__section = section
+        self.__option = option
+        self.__value = None
+
+    def __str__(self):
+        if not self.__value:
+            self.__value = config.get(self.__section, self.__option)
+        return self.__value
 
 
 # cached extensions
diff --git a/stgit/gitmergeonefile.py b/stgit/gitmergeonefile.py
index 47ad8b8..39915fb 100644
--- a/stgit/gitmergeonefile.py
+++ b/stgit/gitmergeonefile.py
@@ -20,7 +20,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 
 import sys, os
 from stgit import basedir
-from stgit.config import config, file_extensions
+from stgit.config import file_extensions, ConfigOption
 from stgit.utils import append_string
 
 
@@ -31,12 +31,8 @@ class GitMergeException(Exception):
 #
 # Options
 #
-try:
-    merger = config.get('stgit', 'merger')
-    keeporig = config.get('stgit', 'keeporig')
-except Exception, err:
-    raise GitMergeException, 'Configuration error: %s' % err
-
+merger = ConfigOption('stgit', 'merger')
+keeporig = ConfigOption('stgit', 'keeporig')
 
 #
 # Utility functions
diff --git a/stgit/main.py b/stgit/main.py
index 60df5ef..c2797c9 100644
--- a/stgit/main.py
+++ b/stgit/main.py
@@ -220,12 +220,16 @@ def main():
 
     # These modules are only used from this point onwards and do not
     # need to be imported earlier
+    from stgit.config import config_setup
+    from ConfigParser import ParsingError
     from stgit.stack import Series, StackException
     from stgit.git import GitException
     from stgit.commands.common import CmdException
     from stgit.gitmergeonefile import GitMergeException
 
     try:
+        config_setup()
+
         # 'clone' doesn't expect an already initialised GIT tree. A Series
         # object will be created after the GIT tree is cloned
         if cmd != 'clone':
@@ -236,7 +240,7 @@ def main():
             stgit.commands.common.crt_series = command.crt_series
 
         command.func(parser, options, args)
-    except (IOError, CmdException, StackException, GitException,
+    except (IOError, ParsingError, CmdException, StackException, GitException,
             GitMergeException), err:
         print >> sys.stderr, '%s %s: %s' % (prog, cmd, err)
         sys.exit(2)
-- 
2.11.0