use 'with open' for more file-opens

src/allmydata/blacklist.py

@@ -34,7 +34,8 @@ class Blacklist(object):
         try:
             if self.last_mtime is None or current_mtime > self.last_mtime:
                 self.entries.clear()
-                for line in open(self.blacklist_fn, "r").readlines():
+                with open(self.blacklist_fn, "r") as f:
+                    for line in f.readlines():
                         line = line.strip()
                         if not line or line.startswith("#"):
                             continue

src/allmydata/control.py

@@ -19,7 +19,8 @@ def get_memory_usage():
                   "VmData")
     stats = {}
     try:
-        for line in open("/proc/self/status", "r").readlines():
+        with open("/proc/self/status", "r") as f:
+            for line in f.readlines():
                 name, right = line.split(":",2)
                 if name in stat_names:
                     assert right.endswith(" kB\n")

src/allmydata/frontends/auth.py

@@ -31,7 +31,8 @@ class AccountFileChecker(object):
         self.passwords = {}
         self.pubkeys = {}
         self.rootcaps = {}
-        for line in open(abspath_expanduser_unicode(accountfile), "r"):
+        with open(abspath_expanduser_unicode(accountfile), "r") as f:
+            for line in f.readlines():
                 line = line.strip()
                 if line.startswith("#") or not line:
                     continue

src/allmydata/scripts/common.py

@@ -131,14 +131,14 @@ def get_aliases(nodedir):
     aliasfile = os.path.join(nodedir, "private", "aliases")
     rootfile = os.path.join(nodedir, "private", "root_dir.cap")
     try:
-        f = open(rootfile, "r")
+        with open(rootfile, "r") as f:
             rootcap = f.read().strip()
             if rootcap:
                 aliases[DEFAULT_ALIAS] = rootcap
     except EnvironmentError:
         pass
     try:
-        f = codecs.open(aliasfile, "r", "utf-8")
+        with codecs.open(aliasfile, "r", "utf-8") as f:
             for line in f.readlines():
                 line = line.strip()
                 if line.startswith("#") or not line:

src/allmydata/stats.py

@@ -250,8 +250,8 @@ class JSONStatsGatherer(StdOutStatsGatherer):
         self.jsonfile = os.path.join(basedir, "stats.json")
 
         if os.path.exists(self.jsonfile):
-            f = open(self.jsonfile, 'rb')
             try:
+                with open(self.jsonfile, 'rb') as f:
                     self.gathered_stats = json.load(f)
             except Exception:
                 print("Error while attempting to load stats file %s.\n"
@@ -259,7 +259,6 @@ class JSONStatsGatherer(StdOutStatsGatherer):
                       " or delete it if no backup is available.\n" %
                       quote_local_unicode_path(self.jsonfile))
                 raise
-            f.close()
         else:
             self.gathered_stats = {}
 
@@ -272,9 +271,8 @@ class JSONStatsGatherer(StdOutStatsGatherer):
 
     def dump_json(self):
         tmp = "%s.tmp" % (self.jsonfile,)
-        f = open(tmp, 'wb')
+        with open(tmp, 'wb') as f:
             json.dump(self.gathered_stats, f)
-        f.close()
         if os.path.exists(self.jsonfile):
             os.unlink(self.jsonfile)
         os.rename(tmp, self.jsonfile)

src/allmydata/storage/crawler.py

@@ -191,9 +191,8 @@ class ShareCrawler(service.MultiService):
         #                            of the last bucket to be processed, or
         #                            None if we are sleeping between cycles
         try:
-            f = open(self.statefile, "rb")
+            with open(self.statefile, "rb") as f:
                 state = pickle.load(f)
-            f.close()
         except Exception:
             state = {"version": 1,
                      "last-cycle-finished": None,
@@ -230,9 +229,8 @@ class ShareCrawler(service.MultiService):
             last_complete_prefix = self.prefixes[lcpi]
         self.state["last-complete-prefix"] = last_complete_prefix
         tmpfile = self.statefile + ".tmp"
-        f = open(tmpfile, "wb")
+        with open(tmpfile, "wb") as f:
             pickle.dump(self.state, f)
-        f.close()
         fileutil.move_into_place(tmpfile, self.statefile)
 
     def startService(self):

src/allmydata/storage/expirer.py

@@ -84,9 +84,8 @@ class LeaseCheckingCrawler(ShareCrawler):
         # initialize history
         if not os.path.exists(self.historyfile):
             history = {} # cyclenum -> dict
-            f = open(self.historyfile, "wb")
+            with open(self.historyfile, "wb") as f:
                 pickle.dump(history, f)
-            f.close()
 
     def create_empty_cycle_dict(self):
         recovered = self.create_empty_recovered_dict()
@@ -303,14 +302,14 @@ class LeaseCheckingCrawler(ShareCrawler):
         # copy() needs to become a deepcopy
         h["space-recovered"] = s["space-recovered"].copy()
 
-        history = pickle.load(open(self.historyfile, "rb"))
+        with open(self.historyfile, "rb") as f:
+            history = pickle.load(f)
         history[cycle] = h
         while len(history) > 10:
             oldcycles = sorted(history.keys())
             del history[oldcycles[0]]
-        f = open(self.historyfile, "wb")
+        with open(self.historyfile, "wb") as f:
             pickle.dump(history, f)
-        f.close()
 
     def get_state(self):
         """In addition to the crawler state described in
@@ -379,7 +378,8 @@ class LeaseCheckingCrawler(ShareCrawler):
         progress = self.get_progress()
 
         state = ShareCrawler.get_state(self) # does a shallow copy
-        history = pickle.load(open(self.historyfile, "rb"))
+        with open(self.historyfile, "rb") as f:
+            history = pickle.load(f)
         state["history"] = history
 
         if not progress["cycle-in-progress"]:

src/allmydata/storage/mutable.py

@@ -57,7 +57,7 @@ class MutableShareFile(object):
         self.home = filename
         if os.path.exists(self.home):
             # we don't cache anything, just check the magic
-            f = open(self.home, 'rb')
+            with open(self.home, 'rb') as f:
                 data = f.read(self.HEADER_SIZE)
             (magic,
              write_enabler_nodeid, write_enabler,
@@ -80,17 +80,17 @@ class MutableShareFile(object):
                               + data_length)
         assert extra_lease_offset == self.DATA_OFFSET # true at creation
         num_extra_leases = 0
-        f = open(self.home, 'wb')
+        with open(self.home, 'wb') as f:
-        header = struct.pack(">32s20s32sQQ",
+            header = struct.pack(
+                ">32s20s32sQQ",
                 self.MAGIC, my_nodeid, write_enabler,
                 data_length, extra_lease_offset,
             )
-        leases = ("\x00"*self.LEASE_SIZE) * 4
+            leases = ("\x00" * self.LEASE_SIZE) * 4
             f.write(header + leases)
             # data goes here, empty after creation
             f.write(struct.pack(">L", num_extra_leases))
             # extra leases go here, none at creation
-        f.close()
 
     def unlink(self):
         os.unlink(self.home)
@@ -261,10 +261,9 @@ class MutableShareFile(object):
 
     def get_leases(self):
         """Yields a LeaseInfo instance for all leases."""
-        f = open(self.home, 'rb')
+        with open(self.home, 'rb') as f:
             for i, lease in self._enumerate_leases(f):
                 yield lease
-        f.close()
 
     def _enumerate_leases(self, f):
         for i in range(self._get_num_lease_slots(f)):
@@ -277,18 +276,17 @@ class MutableShareFile(object):
 
     def add_lease(self, lease_info):
         precondition(lease_info.owner_num != 0) # 0 means "no lease here"
-        f = open(self.home, 'rb+')
+        with open(self.home, 'rb+') as f:
             num_lease_slots = self._get_num_lease_slots(f)
             empty_slot = self._get_first_empty_lease_slot(f)
             if empty_slot is not None:
                 self._write_lease_record(f, empty_slot, lease_info)
             else:
                 self._write_lease_record(f, num_lease_slots, lease_info)
-        f.close()
 
     def renew_lease(self, renew_secret, new_expire_time):
         accepting_nodeids = set()
-        f = open(self.home, 'rb+')
+        with open(self.home, 'rb+') as f:
             for (leasenum,lease) in self._enumerate_leases(f):
                 if timing_safe_compare(lease.renew_secret, renew_secret):
                     # yup. See if we need to update the owner time.
@@ -296,10 +294,8 @@ class MutableShareFile(object):
                         # yes
                         lease.expiration_time = new_expire_time
                         self._write_lease_record(f, leasenum, lease)
-                f.close()
                     return
                 accepting_nodeids.add(lease.nodeid)
-        f.close()
         # Return the accepting_nodeids set, to give the client a chance to
         # update the leases on a share which has been migrated from its
         # original server to a new one.
@@ -333,7 +329,7 @@ class MutableShareFile(object):
                                 cancel_secret="\x00"*32,
                                 expiration_time=0,
                                 nodeid="\x00"*20)
-        f = open(self.home, 'rb+')
+        with open(self.home, 'rb+') as f:
             for (leasenum,lease) in self._enumerate_leases(f):
                 accepting_nodeids.add(lease.nodeid)
                 if timing_safe_compare(lease.cancel_secret, cancel_secret):
@@ -372,10 +368,9 @@ class MutableShareFile(object):
 
     def readv(self, readv):
         datav = []
-        f = open(self.home, 'rb')
+        with open(self.home, 'rb') as f:
             for (offset, length) in readv:
                 datav.append(self._read_share_data(f, offset, length))
-        f.close()
         return datav
 
 #    def remote_get_length(self):
@@ -385,10 +380,9 @@ class MutableShareFile(object):
 #        return data_length
 
     def check_write_enabler(self, write_enabler, si_s):
-        f = open(self.home, 'rb+')
+        with open(self.home, 'rb+') as f:
             (real_write_enabler, write_enabler_nodeid) = \
                                  self._read_write_enabler_and_nodeid(f)
-        f.close()
         # avoid a timing attack
         #if write_enabler != real_write_enabler:
         if not timing_safe_compare(write_enabler, real_write_enabler):
@@ -405,17 +399,16 @@ class MutableShareFile(object):
 
     def check_testv(self, testv):
         test_good = True
-        f = open(self.home, 'rb+')
+        with open(self.home, 'rb+') as f:
             for (offset, length, operator, specimen) in testv:
                 data = self._read_share_data(f, offset, length)
                 if not testv_compare(data, operator, specimen):
                     test_good = False
                     break
-        f.close()
         return test_good
 
     def writev(self, datav, new_length):
-        f = open(self.home, 'rb+')
+        with open(self.home, 'rb+') as f:
             for (offset, data) in datav:
                 self._write_share_data(f, offset, data)
             if new_length is not None:
@@ -425,7 +418,6 @@ class MutableShareFile(object):
                     # TODO: if we're going to shrink the share file when the
                     # share data has shrunk, then call
                     # self._change_container_size() here.
-        f.close()
 
 def testv_compare(a, op, b):
     assert op in ("lt", "le", "eq", "ne", "ge", "gt")

src/allmydata/storage/server.py

@@ -317,9 +317,8 @@ class StorageServer(service.MultiService, Referenceable):
 
     def _iter_share_files(self, storage_index):
         for shnum, filename in self._get_bucket_shares(storage_index):
-            f = open(filename, 'rb')
+            with open(filename, 'rb') as f:
                 header = f.read(32)
-            f.close()
             if header[:32] == MutableShareFile.MAGIC:
                 sf = MutableShareFile(filename, self)
                 # note: if the share has been migrated, the renew_lease()
@@ -682,7 +681,7 @@ class StorageServer(service.MultiService, Referenceable):
         # windows can't handle colons in the filename
         fn = os.path.join(self.corruption_advisory_dir,
                           "%s--%s-%d" % (now, si_s, shnum)).replace(":","")
-        f = open(fn, "w")
+        with open(fn, "w") as f:
             f.write("report: Share Corruption\n")
             f.write("type: %s\n" % share_type)
             f.write("storage_index: %s\n" % si_s)
@@ -690,7 +689,6 @@ class StorageServer(service.MultiService, Referenceable):
             f.write("\n")
             f.write(reason)
             f.write("\n")
-        f.close()
         log.msg(format=("client claims corruption in (%(share_type)s) " +
                         "%(si)s-%(shnum)d: %(reason)s"),
                 share_type=share_type, si=si_s, shnum=shnum, reason=reason,

src/allmydata/storage/shares.py

@@ -4,9 +4,8 @@ from allmydata.storage.mutable import MutableShareFile
 from allmydata.storage.immutable import ShareFile
 
 def get_share_file(filename):
-    f = open(filename, "rb")
+    with open(filename, "rb") as f:
         prefix = f.read(32)
-    f.close()
     if prefix == MutableShareFile.MAGIC:
         return MutableShareFile(filename)
     # otherwise assume it's immutable

src/allmydata/util/configutil.py

@@ -13,15 +13,12 @@ class UnknownConfigError(Exception):
 
 def get_config(tahoe_cfg):
     config = SafeConfigParser()
-    f = open(tahoe_cfg, "rb")
+    with open(tahoe_cfg, "rb") as f:
-    try:
         # Skip any initial Byte Order Mark. Since this is an ordinary file, we
         # don't need to handle incomplete reads, and can assume seekability.
         if f.read(3) != '\xEF\xBB\xBF':
             f.seek(0)
         config.readfp(f)
-    finally:
-        f.close()
     return config
 
 def set_config(config, section, option, value):
@@ -31,11 +28,8 @@ def set_config(config, section, option, value):
     assert config.get(section, option) == value
 
 def write_config(tahoe_cfg, config):
-    f = open(tahoe_cfg, "wb")
+    with open(tahoe_cfg, "wb") as f:
-    try:
         config.write(f)
-    finally:
-        f.close()
 
 def validate_config(fname, cfg, valid_config):
     """

src/allmydata/version_checks.py

@@ -235,7 +235,7 @@ def _get_linux_distro():
         return (_distname, _version)
 
     try:
-        etclsbrel = open("/etc/lsb-release", "rU")
+        with open("/etc/lsb-release", "rU") as etclsbrel:
             for line in etclsbrel:
                 m = _distributor_id_file_re.search(line)
                 if m: