From: Zooko O'Whielacronx <zooko@zooko.com>
Date: Wed, 22 Aug 2007 17:29:57 +0000 (-0700)
Subject: refactor reading of configuration files in client.py
X-Git-Url: https://git.rkrishnan.org/architecture.txt?a=commitdiff_plain;h=8717905e35585a0e629b4f639e0b1c2ea2bfb64a;p=tahoe-lafs%2Ftahoe-lafs.git

refactor reading of configuration files in client.py
This makes it so that an optional file which is unreadable or is rm'ed
at the wrong moment will be ignored instead of raising an exception.
It also bums out a couple of unnecessary lines of code (the explicit
".close()" call).
---

diff --git a/src/allmydata/client.py b/src/allmydata/client.py
index e15cae28..5976a7b1 100644
--- a/src/allmydata/client.py
+++ b/src/allmydata/client.py
@@ -44,23 +44,20 @@ class Client(node.Node, Referenceable):
         self.add_service(Uploader())
         self.add_service(Downloader())
         self.add_service(VirtualDrive())
-        WEBPORTFILE = os.path.join(self.basedir, self.WEBPORTFILE)
-        if os.path.exists(WEBPORTFILE):
-            f = open(WEBPORTFILE, "r")
-            webport = f.read().strip() # strports string
-            f.close()
+        try:
+            webport = open(os.path.join(self.basedir, self.WEBPORTFILE),
+                           "r").read().strip() # strports string
+        except EnvironmentError:
+            pass # absent or unreadable webport file
+        else:
             ws = WebishServer(webport)
-            local_access_file = os.path.join(self.basedir,
-                                             self.WEB_ALLOW_LOCAL_ACCESS_FILE)
-            if os.path.exists(local_access_file):
-                ws.allow_local_access(True)
+            ws.allow_local_access(os.path.exists(os.path.join(self.basedir,
+                                  self.WEB_ALLOW_LOCAL_ACCESS_FILE)))
             self.add_service(ws)
 
         INTRODUCER_FURL_FILE = os.path.join(self.basedir,
                                             self.INTRODUCER_FURL_FILE)
-        f = open(INTRODUCER_FURL_FILE, "r")
-        self.introducer_furl = f.read().strip()
-        f.close()
+        self.introducer_furl = open(INTRODUCER_FURL_FILE, "r").read().strip()
 
         hotline_file = os.path.join(self.basedir,
                                     self.SUICIDE_PREVENTION_HOTLINE_FILE)
@@ -72,12 +69,13 @@ class Client(node.Node, Referenceable):
     def init_storage(self):
         storedir = os.path.join(self.basedir, self.STOREDIR)
         sizelimit = None
-        SIZELIMIT_FILE = os.path.join(self.basedir,
-                                      self.SIZELIMIT_FILE)
-        if os.path.exists(SIZELIMIT_FILE):
-            f = open(SIZELIMIT_FILE, "r")
-            data = f.read().strip()
-            f.close()
+
+        try:
+            data = open(os.path.join(self.basedir, self.SIZELIMIT_FILE),
+                        "r").read().strip()
+        except EnvironmentError:
+            pass # absent or unreadable sizelimit file
+        else:
             m = re.match(r"^(\d+)([kKmMgG]?[bB]?)$", data)
             if not m:
                 log.msg("SIZELIMIT_FILE contains unparseable value %s" % data)
@@ -114,16 +112,18 @@ class Client(node.Node, Referenceable):
         self.log("tub_ready")
 
         my_old_name = None
-        MYSELF_FURL_PATH = os.path.join(self.basedir, self.MY_FURL_FILE)
-        if os.path.exists(MYSELF_FURL_PATH):
-            my_old_furl = open(MYSELF_FURL_PATH, "r").read().strip()
+        try:
+            my_old_furl = open(os.path.join(self.basedir, self.MY_FURL_FILE),
+                               "r").read().strip()
+        except EnvironmentError:
+            pass # absent or unreadable myfurl file
+        else:
             sturdy = SturdyRef(my_old_furl)
             my_old_name = sturdy.name
 
         self.my_furl = self.tub.registerReference(self, my_old_name)
-        f = open(MYSELF_FURL_PATH, "w")
-        f.write(self.my_furl + "\n")
-        f.close()
+        open(os.path.join(self.basedir, self.MY_FURL_FILE),
+             "w").write(self.my_furl + "\n")
 
         ic = IntroducerClient(self.tub, self.introducer_furl, self.my_furl)
         self.introducer_client = ic
@@ -136,9 +136,7 @@ class Client(node.Node, Referenceable):
         c.setServiceParent(self)
         control_url = self.tub.registerReference(c)
         control_furl_file = os.path.join(self.basedir, "control.furl")
-        f = open(control_furl_file, "w")
-        f.write(control_url + "\n")
-        f.close()
+        open(control_furl_file, "w").write(control_url + "\n")
         os.chmod(control_furl_file, 0600)