From 0e5084eeb39f75fc5910e1d4d4ad2449e471d603 Mon Sep 17 00:00:00 2001
From: Michael Hanselmann <hansmi@google.com>
Date: Thu, 4 Aug 2011 18:38:38 +0200
Subject: [PATCH] utils.ReadFile: Add pre-read callback
This will be used by the watcher to store the file's fstat(2). It must
be done from the filehandle.
Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>
---
lib/utils/io.py | 7 ++++++-
test/ganeti.utils.io_unittest.py | 6 ++++++
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/lib/utils/io.py b/lib/utils/io.py
index 4c1df6c17..413a119c7 100644
--- a/lib/utils/io.py
+++ b/lib/utils/io.py
@@ -38,17 +38,22 @@ from ganeti.utils import filelock
_RANDOM_UUID_FILE = "/proc/sys/kernel/random/uuid"
-def ReadFile(file_name, size=-1):
+def ReadFile(file_name, size=-1, preread=None):
"""Reads a file.
@type size: int
@param size: Read at most size bytes (if negative, entire file)
+ @type preread: callable receiving file handle as single parameter
+ @param preread: Function called before file is read
@rtype: str
@return: the (possibly partial) content of the file
"""
f = open(file_name, "r")
try:
+ if preread:
+ preread(f)
+
return f.read(size)
finally:
f.close()
diff --git a/test/ganeti.utils.io_unittest.py b/test/ganeti.utils.io_unittest.py
index ed67f6898..be1b4abb6 100755
--- a/test/ganeti.utils.io_unittest.py
+++ b/test/ganeti.utils.io_unittest.py
@@ -55,6 +55,12 @@ class TestReadFile(testutils.GanetiTestCase):
h.update(data)
self.assertEqual(h.hexdigest(), "893772354e4e690b9efd073eed433ce7")
+ def testCallback(self):
+ def _Cb(fh):
+ self.assertEqual(fh.tell(), 0)
+ data = utils.ReadFile(self._TestDataFilename("cert1.pem"), preread=_Cb)
+ self.assertEqual(len(data), 814)
+
def testError(self):
self.assertRaises(EnvironmentError, utils.ReadFile,
"/dev/null/does-not-exist")
--
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