From 749e4ff2a7468d546ad6983c6e8659ea0d5c59da Mon Sep 17 00:00:00 2001
From: Daira Hopwood <daira@jacaranda.org>
Date: Mon, 28 Dec 2015 20:07:55 +0000
Subject: [PATCH] Add get_pathinfo.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>
---
 src/allmydata/scripts/backupdb.py |  2 ++
 src/allmydata/test/test_util.py   | 54 +++++++++++++++++++++++++++++++
 src/allmydata/util/fileutil.py    | 31 ++++++++++++++++++
 3 files changed, 87 insertions(+)

diff --git a/src/allmydata/scripts/backupdb.py b/src/allmydata/scripts/backupdb.py
index d0c22616..33aa952e 100644
--- a/src/allmydata/scripts/backupdb.py
+++ b/src/allmydata/scripts/backupdb.py
@@ -173,6 +173,8 @@ class BackupDB_v2:
         """
 
         path = abspath_expanduser_unicode(path)
+
+        # TODO: consider using get_pathinfo.
         s = os.stat(path)
         size = s[stat.ST_SIZE]
         ctime = s[stat.ST_CTIME]
diff --git a/src/allmydata/test/test_util.py b/src/allmydata/test/test_util.py
index 606dc6c5..345b87cc 100644
--- a/src/allmydata/test/test_util.py
+++ b/src/allmydata/test/test_util.py
@@ -584,6 +584,60 @@ class FileUtil(ReallyEqualMixin, unittest.TestCase):
         disk = fileutil.get_disk_stats('.', 2**128)
         self.failUnlessEqual(disk['avail'], 0)
 
+    def test_get_pathinfo(self):
+        basedir = "util/FileUtil/test_get_pathinfo"
+        fileutil.make_dirs(basedir)
+
+        # create a directory
+        self.mkdir(basedir, "a")
+        dirinfo = fileutil.get_pathinfo(basedir)
+        self.failUnlessTrue(dirinfo.isdir)
+        self.failUnlessTrue(dirinfo.exists)
+        self.failUnlessFalse(dirinfo.isfile)
+        self.failUnlessFalse(dirinfo.islink)
+
+        # create a file
+        f = os.path.join(basedir, "1.txt")
+        fileutil.write(f, "a"*10)
+        fileinfo = fileutil.get_pathinfo(f)
+        self.failUnlessTrue(fileinfo.isfile)
+        self.failUnlessTrue(fileinfo.exists)
+        self.failUnlessFalse(fileinfo.isdir)
+        self.failUnlessFalse(fileinfo.islink)
+        self.failUnlessEqual(fileinfo.size, 10)
+
+        # path at which nothing exists
+        dnename = os.path.join(basedir, "doesnotexist")
+        now = time.time()
+        dneinfo = fileutil.get_pathinfo(dnename, now=now)
+        self.failUnlessFalse(dneinfo.exists)
+        self.failUnlessFalse(dneinfo.isfile)
+        self.failUnlessFalse(dneinfo.isdir)
+        self.failUnlessFalse(dneinfo.islink)
+        self.failUnlessEqual(dneinfo.size, None)
+        self.failUnlessEqual(dneinfo.mtime, now)
+        self.failUnlessEqual(dneinfo.ctime, now)
+
+    def test_get_pathinfo_symlink(self):
+        if not hasattr(os, 'symlink'):
+            raise unittest.SkipTest("can't create symlinks on this platform")
+
+        basedir = "util/FileUtil/test_get_pathinfo"
+        fileutil.make_dirs(basedir)
+
+        f = os.path.join(basedir, "1.txt")
+        fileutil.write(f, "a"*10)
+
+        # create a symlink pointing to 1.txt
+        slname = os.path.join(basedir, "linkto1.txt")
+        os.symlink(f, slname)
+        symlinkinfo = fileutil.get_pathinfo(slname)
+        self.failUnlessTrue(symlinkinfo.islink)
+        self.failUnlessTrue(symlinkinfo.exists)
+        self.failUnlessFalse(symlinkinfo.isfile)
+        self.failUnlessFalse(symlinkinfo.isdir)
+
+
 class PollMixinTests(unittest.TestCase):
     def setUp(self):
         self.pm = pollmixin.PollMixin()
diff --git a/src/allmydata/util/fileutil.py b/src/allmydata/util/fileutil.py
index a6b7ce06..ac82fee9 100644
--- a/src/allmydata/util/fileutil.py
+++ b/src/allmydata/util/fileutil.py
@@ -3,6 +3,8 @@ Futz with files like a pro.
 """
 
 import sys, exceptions, os, stat, tempfile, time, binascii
+from collections import namedtuple
+from errno import ENOENT
 
 from twisted.python import log
 
@@ -514,3 +516,32 @@ def get_available_space(whichdir, reserved_space):
     except EnvironmentError:
         log.msg("OS call to get disk statistics failed")
         return 0
+
+
+PathInfo = namedtuple('PathInfo', 'isdir isfile islink exists size mtime ctime')
+
+def get_pathinfo(path_u, now=None):
+    try:
+        statinfo = os.lstat(path_u)
+        mode = statinfo.st_mode
+        return PathInfo(isdir =stat.S_ISDIR(mode),
+                        isfile=stat.S_ISREG(mode),
+                        islink=stat.S_ISLNK(mode),
+                        exists=True,
+                        size  =statinfo.st_size,
+                        mtime =statinfo.st_mtime,
+                        ctime =statinfo.st_ctime,
+                       )
+    except OSError as e:
+        if e.errno == ENOENT:
+            if now is None:
+                now = time.time()
+            return PathInfo(isdir =False,
+                            isfile=False,
+                            islink=False,
+                            exists=False,
+                            size  =None,
+                            mtime =now,
+                            ctime =now,
+                           )
+        raise
-- 
2.45.2