[Checkins] SVN: zc.recipe.cmmi/branches/miles-download-cache/zc/recipe/cmmi/__init__.py Factor out the getFromCache method so it can be used in other recipes.

[Miles Waller]

Log message for revision 78556:
  Factor out the getFromCache method so it can be used in other recipes.
  
  Perhaps something generic like this belongs in zc.buildout rather than 
  this specific recipe.  Would be nice to specify the cache name rather 
  than passing the full path around.
  
  

Changed:
  U   zc.recipe.cmmi/branches/miles-download-cache/zc/recipe/cmmi/__init__.py

-=-
Modified: zc.recipe.cmmi/branches/miles-download-cache/zc/recipe/cmmi/__init__.py
===================================================================
--- zc.recipe.cmmi/branches/miles-download-cache/zc/recipe/cmmi/__init__.py	2007-08-03 14:31:14 UTC (rev 78555)
+++ zc.recipe.cmmi/branches/miles-download-cache/zc/recipe/cmmi/__init__.py	2007-08-03 17:45:45 UTC (rev 78556)
@@ -30,17 +30,12 @@
         self.download_cache = buildout['buildout'].get('download-cache')
         self.install_from_cache = buildout['buildout'].get('install-from-cache')
 
-        url = self.options['url']
-        _, _, urlpath, _, _, _ = urlparse.urlparse(url)
-        self.filename = urlpath.split('/')[-1]
         if self.download_cache:
             # cache keys are hashes of url, to ensure repeatability if the
             # downloads do not have a version number in the filename
             # cache key is a directory which contains the downloaded file
             # download details stored with each key as cache.ini
-            cache_fname = sha.new(url).hexdigest()
             self.download_cache = os.path.join(directory, self.download_cache, 'cmmi')
-            self.cache_name = os.path.join(self.download_cache, cache_fname)
 
         # we assume that install_from_cache and download_cache values
         # are correctly set, and that the download_cache directory has
@@ -62,65 +57,8 @@
         patch = self.options.get('patch', '')
         patch_options = self.options.get('patch_options', '-p0')
 
-        if self.download_cache:
-            if not os.path.isdir(self.download_cache):
-                os.mkdir(self.download_cache)
-
-        # get the file from the right place
-        fname, tmp2 = None, None
-        if self.download_cache:
-            # if we have a cache, try and use it
-            logging.getLogger(self.name).debug(
-                'Searching cache at %s' % self.download_cache )
-            if os.path.isdir(self.cache_name):
-                # just cache files for now
-                fname = os.path.join(self.cache_name, self.filename)
-                logging.getLogger(self.name).debug(
-                    'Using cache file %s' % self.cache_name )
-
-            else:
-                logging.getLogger(self.name).debug(
-                    'Did not find %s under cache key %s' % (self.filename, self.cache_name) )
-
-        if not fname:
-            if self.install_from_cache:
-                # no file in the cache, but we are staying offline
-                raise zc.buildout.UserError(
-                    "Offline mode: file from %s not found in the cache at %s" % 
-                    (url, self.download_cache) )
-
-            try:
-                # okay, we've got to download now
-                # XXX: do we need to do something about permissions
-                # XXX: in case the cache is shared across users?
-                tmp2 = None
-                if self.download_cache:
-                    # set up the cache and download into it
-                    os.mkdir(self.cache_name)
-                    fname = os.path.join(self.cache_name, self.filename)
-                    if self.filename != "cache.ini":
-                        now = datetime.datetime.utcnow()
-                        cache_ini = open(os.path.join(self.cache_name, "cache.ini"), "w")
-                        print >>cache_ini, "[cache]"
-                        print >>cache_ini, "download_url =", url
-                        print >>cache_ini, "retrieved =", now.isoformat() + "Z"
-                        cache_ini.close()
-                    logging.getLogger(self.name).debug(
-                        'Cache download %s as %s' % (url, self.cache_name) )
-                else:
-                    # use tempfile
-                    tmp2 = tempfile.mkdtemp('buildout-'+self.name)
-                    fname = os.path.join(tmp2, self.filename)
-                    logging.getLogger(self.name).info(
-                        'Downloading %s' % url )
-                open(fname, 'w').write(urllib2.urlopen(url).read())
-            except:
-                if tmp2 is not None:
-                   shutil.rmtree(tmp2)
-                if self.download_cache:
-                   shutil.rmtree(self.cache_name)
-                raise
-
+        fname = getFromCache( url, self.name, self.download_cache, self.install_from_cache)
+ 
         try:
             # now unpack and work as normal
             tmp = tempfile.mkdtemp('buildout-'+self.name)
@@ -159,4 +97,70 @@
 
     def update(self):
         pass
+
+def getFromCache(url, name, download_cache=None, install_from_cache=False):
+    if download_cache:
+        cache_fname = sha.new(url).hexdigest()
+        cache_name = os.path.join(download_cache, cache_fname)
+        if not os.path.isdir(download_cache):
+            os.mkdir(download_cache)
+
+    _, _, urlpath, _, _, _ = urlparse.urlparse(url)
+    filename = urlpath.split('/')[-1]
+
+    # get the file from the right place
+    fname, tmp2 = None, None
+    if download_cache:
+        # if we have a cache, try and use it
+        logging.getLogger(name).debug(
+            'Searching cache at %s' % download_cache )
+        if os.path.isdir(cache_name):
+            # just cache files for now
+            fname = os.path.join(cache_name, filename)
+            logging.getLogger(name).debug(
+                'Using cache file %s' % cache_name )
+
+        else:
+            logging.getLogger(name).debug(
+                'Did not find %s under cache key %s' % (filename, cache_name) )
+
+    if not fname:
+        if install_from_cache:
+            # no file in the cache, but we are staying offline
+            raise zc.buildout.UserError(
+                "Offline mode: file from %s not found in the cache at %s" %
+                (url, download_cache) )
+        try:
+            # okay, we've got to download now
+            # XXX: do we need to do something about permissions
+            # XXX: in case the cache is shared across users?
+            tmp2 = None
+            if download_cache:
+                # set up the cache and download into it
+                os.mkdir(cache_name)
+                fname = os.path.join(cache_name, filename)
+                if filename != "cache.ini":
+                    now = datetime.datetime.utcnow()
+                    cache_ini = open(os.path.join(cache_name, "cache.ini"), "w")                    print >>cache_ini, "[cache]"
+                    print >>cache_ini, "download_url =", url
+                    print >>cache_ini, "retrieved =", now.isoformat() + "Z"
+                    cache_ini.close()
+                logging.getLogger(name).debug(
+                    'Cache download %s as %s' % (url, cache_name) )
+            else:
+                # use tempfile
+                tmp2 = tempfile.mkdtemp('buildout-'+name)
+                fname = os.path.join(tmp2, filename)
+                logging.getLogger(name).info(
+                    'Downloading %s' % url )
+            open(fname, 'w').write(urllib2.urlopen(url).read())
+        except:
+            if tmp2 is not None:
+               shutil.rmtree(tmp2)
+            if download_cache:
+               shutil.rmtree(cache_name)
+            raise
+
+    return fname
+