adding a caching mechanism.

uranium/scripts/uranium

@@ -5,14 +5,35 @@
 # * run uranium
 import os
 
+ROOT = os.path.dirname(__file__)
 URANIUM_PATH = os.getenv('URANIUM_PATH', None)
 URANIUM_GITHUB_ACCOUNT = os.getenv('URANIUM_GITHUB_ACCOUNT', 'toumorokoshi')
 URANIUM_GITHUB_BRANCH = os.getenv('URANIUM_GITHUB_BRANCH', 'master')
 URANIUM_STANDALONE_URL = "https://raw.githubusercontent.com/{account}/uranium/{branch}/uranium/scripts/uranium_standalone".format(account=URANIUM_GITHUB_ACCOUNT, branch=URANIUM_GITHUB_BRANCH)
+CACHE_DIRECTORY = os.path.join(ROOT, ".uranium")
+CACHED_URANIUM_STANDALONE = os.path.join(CACHE_DIRECTORY, "uranium_standalone")
+
+
+def get_cached_standalone():
+    if not os.path.isfile(CACHED_URANIUM_STANDALONE):
+        return None
+    with open(CACHED_URANIUM_STANDALONE) as fh:
+        return fh.read().decode("UTF-8")
+
+
+def store_cached_standalone(body):
+    if not os.path.exists(CACHE_DIRECTORY):
+        os.makedirs(CACHE_DIRECTORY)
+    with open(CACHED_URANIUM_STANDALONE, "w+") as fh:
+        fh.write(body)
+
+cached_standalone = get_cached_standalone()
 
 if URANIUM_PATH is not None:
     print("Executing uranium from " + URANIUM_PATH)
     execfile(os.path.realpath(URANIUM_PATH))
+elif cached_standalone is not None:
+    exec(cached_standalone)
 else:
     print("Downloading uranium from " + URANIUM_STANDALONE_URL)
     try:
@@ -22,4 +43,6 @@ else:
 
     print("loading uranium bootstrapper...")
     body = urlopen(URANIUM_STANDALONE_URL).read()
+    print("caching standalone uranium script...")
+    store_cached_standalone(body)
     exec(body)

uranium/scripts/uranium_standalone

@@ -129,12 +129,9 @@ def main(argv):
 
     os.chdir(current_dir)
 
-    LOGGER.info("setting up uranium...")
     _install_uranium(install_dir, uranium_dir=uranium_dir,
                      version=options.version)
 
-    LOGGER.info("done!")
-
     LOGGER.debug("running uranium...")
     return _run_uranium(install_dir, remaining_args)
 
@@ -199,6 +196,11 @@ sys.path += paths_to_append
 
 
 def _install_uranium(virtualenv_dir, uranium_dir=None, version=None):
+    uranium_executable = os.path.join(virtualenv_dir, 'bin', 'uranium')
+    if os.path.exists(uranium_executable):
+        return
+
+    LOGGER.info("setting up uranium...")
     if uranium_dir:
         uranium_dir = os.path.expanduser(uranium_dir)
 
@@ -221,6 +223,7 @@ def _install_uranium(virtualenv_dir, uranium_dir=None, version=None):
                 log_file
             ))
             exit(1)
+    LOGGER.info("done!")
 
 
 def _run_uranium(virtualenv_dir, args):