Merge lp:~sylvain-pineau/checkbox-core/bug983035 into lp:checkbox-core

[Sylvain Pineau]

This MR replaces the file wrapper class with a new one that inherits of io.fileIO.
Classes depending on the old file interface have been updated as well.

[Marc Tardif (cr3)]

Excellent work looking info fileobject.c! I just commented on the bug linked to this branch a couple minutes ago, do you think we should add more methods to this story?

review: Needs Information

[lp:~sylvain-pineau/checkbox-core/bug983035]

15. By Marc Tardif on 2012-04-24

Merged from javier.collado's staticmethods branch.

16. By Marc Tardif on 2012-04-24

Preliminary submit and shadowd components.

17. By Marc Tardif on 2012-04-25

Merged from javier.collado's package-docstrings branch.

[Sylvain Pineau (sylvain-pineau)]

A new proposal based this time on io.FileIO

review: Needs Resubmitting

[lp:~sylvain-pineau/checkbox-core/bug983035]

18. By Sylvain Pineau on 2012-04-25

merge trunk recent updates

19. By Sylvain Pineau on 2012-04-26

File class now inherits from io.FileIO

[Sylvain Pineau (sylvain-pineau)]

io.FileIO is now used as a base class to checkbox.lib.file

review: Needs Resubmitting

[lp:~sylvain-pineau/checkbox-core/bug983035]

20. By Sylvain Pineau on 2012-04-30

Fix classes that now depends on the new File/io.FileIO class

[Sylvain Pineau (sylvain-pineau)]

I've fixed classes that used the old file interface to match the new way we built file objects.

review: Needs Resubmitting

[lp:~sylvain-pineau/checkbox-core/bug983035]

21. By Sylvain Pineau on 2012-04-30

fix reamining calls to File.create_from*

22. By Sylvain Pineau on 2012-04-30

Remove unused import of File in watchdog.py

[Marc Tardif (cr3)]

Nice work, I'm very pleased about removing the create_from_* class methods and using None instead of an empty File instance! First, I don't think this logic is the same as before:

324 - if (self._user_enable
325 - and not self._openPath(path, self._file, lock=self._lock)):
326 + self._file = self._openPath(path, lock=self._lock)
327 + if (self._user_enable and not self._file):

Before, _openPath was only called if _user_enable is True. Now, _openPath is always called. Second, I think this code is a bit ambiguous because self._writer is not expected to be boolean:

141 + return self._writer == True

Even though your code probably works, I think it's more obvious to say something like: return self._writer is not None. Last, but not least, what would you think about changing Fifo.create_fifo to just be a function, instead of a class method, that would return a reader and writer tuple?

review: Needs Fixing

[lp:~sylvain-pineau/checkbox-core/bug983035]

23. By Sylvain Pineau on 2012-05-02

Fix a call to _openPath in writer.py and rewrite the returned boolean of connect and listen functions in pipe.py

24. By Sylvain Pineau on 2012-05-02

Revert Fifo.create_fifo into a function instead of a class method returning a reader and writer tuple

[Sylvain Pineau (sylvain-pineau)]

Thanks for the review, I've made the suggested changes, both in code and tests.

review: Needs Resubmitting

[Marc Tardif (cr3)]

This code will raise an AttributeError when calling the close() method on a None object:

394 + file = create_file(fd, mode)
395 + if not file:
396 + file.close()

By removing the decorators in checkbox.lib.file, the file object no longer contains the errno attribute used like this in checkbox.daemon.pidentry for example:

  elif buffer is None \
       and file.errno != errno.EWOULDBLOCK \
       and file.errno != errno.EAGAIN:
      logging.info("Read failed for pid %d: %d", pipe_fd, file.errno)
      return False

A quick grep returned other places where file.errno is used. We might either want to reintroduce the previous decorators, but that still won't work in places like in checkbox.journal.multi where errno will be called on a None object. How would you address this problem?

By the way, I really like this unit test which clearly shows that the new behavior of fifo_create is much more elegant:

- read_file = File()
- write_file = File()
-
- self.assertTrue(fifo_create(self.path, read_file, write_file))
- self.assertNotEquals(read_file.fileno(), -1)
- self.assertNotEquals(write_file.fileno(), -1)
+ reader, writer = fifo_create(self.path)
+ self.assertNotEquals(reader.fileno(), -1)
+ self.assertNotEquals(writer.fileno(), -1)

review: Needs Fixing

[Marc Tardif (cr3)]

I just thought of a solution to solve the problem of having create_file somehow return an errno: instead of returning None when an error occurs, we could return the negative errno:

  file = create_file(path)
  if file < 0:
    logging.error("Failed to open file '%s'; errno = %d", path, -file)

This will work when create_file returns an actual object, so the code is safe. The only problem is that the value assigned to file is either an object or a negative integer. This might sound strange but it's not that much diffferent from returning None. For example, both a negative integer and None will raise an AttributeError when attempting to call file.read() when create_file fails. What do you think?

[Sylvain Pineau (sylvain-pineau)]

It's probably the best we can do to keep the calling code quite simple.

I was thinking to reintroduce the errno attribute to the File class, if the file object creation fails, returns the class and check for the errno. Given that the application if not threaded, it could be reliable:

class File(io.FileIO):

    __slots__ = (
        "errno",
        )

    def __init__(self, *args, **kwargs):
        super(File, self).__init__(*args, **kwargs)
        self.errno = 0

[...]

def create_file(*args, **kwargs):
    try:
        return File(*args, **kwargs)
    except (EnvironmentError, ValueError), error:
        f = File
        f.errno = error.errno
        return f

Even if I prefer your proposal, what do you think of mine ?

Unmerged revisions

24. By Sylvain Pineau on 2012-05-02

Revert Fifo.create_fifo into a function instead of a class method returning a reader and writer tuple

23. By Sylvain Pineau on 2012-05-02

Fix a call to _openPath in writer.py and rewrite the returned boolean of connect and listen functions in pipe.py

22. By Sylvain Pineau on 2012-04-30

Remove unused import of File in watchdog.py

21. By Sylvain Pineau on 2012-04-30

fix reamining calls to File.create_from*

20. By Sylvain Pineau on 2012-04-30

Fix classes that now depends on the new File/io.FileIO class

19. By Sylvain Pineau on 2012-04-26

File class now inherits from io.FileIO

18. By Sylvain Pineau on 2012-04-25

merge trunk recent updates

=== modified file 'checkbox/daemon/pidentry.py'
--- checkbox/daemon/pidentry.py	2012-04-23 19:36:19 +0000
+++ checkbox/daemon/pidentry.py	2012-05-02 10:18:20 +0000
@@ -26,7 +26,7 @@
 import logging
 
 from checkbox.lib.file import (
-    File,
+    create_file,
     fd_close,
     )
 
@@ -78,7 +78,7 @@
         max_read_bytes = (
             self.max_pipe_buffer - len(self.pipe_buffer[pipe_index]))
 
-        file = File.create_from_fd(pipe_fd, "r")
+        file = create_file(pipe_fd, "r")
         buffer = file.read(max_read_bytes)
         if buffer:
             self.pipe_buffer[pipe_index] += buffer
@@ -100,7 +100,7 @@
             data_left = buffer[self.stdin_offset:]
             total_len = len(buffer)
 
-            file = File.create_from_fd(pipe_fd, "w")
+            file = create_file(pipe_fd, "w")
             bytes_written = file.write(data_left)
 
         else:

=== modified file 'checkbox/daemon/server.py'
--- checkbox/daemon/server.py	2012-04-23 19:36:19 +0000
+++ checkbox/daemon/server.py	2012-05-02 10:18:20 +0000
@@ -52,7 +52,12 @@
 from time import time
 
 from checkbox.lib.enum import Enum
-from checkbox.lib.file import File, fd_close, fd_get_flags, fd_set_flags
+from checkbox.lib.file import (
+    create_file,
+    fd_close,
+    fd_get_flags,
+    fd_set_flags,
+    )
 from checkbox.lib.sigset import Sigset
 from checkbox.lib.stat import Stat
 
@@ -653,14 +658,14 @@
         if size < 0:
             raise Exception("Invalid size: %d" % size)
 
-        pipe_file = File.create_from_fd(pipe_end, "r")
+        pipe_file = create_file(pipe_end, "r")
         return pipe_file.read(size)
 
     def writePipe(self, pipe_end, buffer):
         if not buffer:
             raise Exception("Invalid buffer, empty")
 
-        pipe_file = File.create_from_fd(pipe_end, "w")
+        pipe_file = create_file(pipe_end, "w")
         return pipe_file.write(buffer)
 
     def closeFd(self, fd):

=== modified file 'checkbox/io/fifo.py'
--- checkbox/io/fifo.py	2012-04-24 22:43:09 +0000
+++ checkbox/io/fifo.py	2012-05-02 10:18:20 +0000
@@ -33,7 +33,7 @@
     fifo_create,
     )
 from checkbox.lib.file import (
-    File,
+    create_file,
     fd_open,
     fd_get_flags,
     fd_set_flags
@@ -78,7 +78,7 @@
         self._pid = 0
         self._serial_number = -1
 
-        self._dummy = File()
+        self._dummy = None
         self._state = FifoState.VIRGIN
 
     def __del__(self):
@@ -267,7 +267,8 @@
 
     def _openReader(self, path):
         # Keep dummy writer open so that reader never receives EOF
-        if not fifo_create(path, self._reader, self._dummy):
+        self._reader, self._dummy = fifo_create(path)
+        if not self._reader or not self._dummy:
             logging.info("Failed to set fifo path at %s", path)
             return False
 
@@ -289,7 +290,7 @@
         if fd_set_flags(write_fd, flags) < 0:
             return False
 
-        self._writer.initialize_from_fd(write_fd, "w")
+        self._writer = create_file(write_fd, "w")
 
         return True
 

=== modified file 'checkbox/io/pipe.py'
--- checkbox/io/pipe.py	2012-04-23 19:36:19 +0000
+++ checkbox/io/pipe.py	2012-05-02 10:18:20 +0000
@@ -24,7 +24,7 @@
 
 import logging
 
-from checkbox.lib.file import File
+from checkbox.lib.file import create_file
 
 from checkbox.io.selector import (
     Selector,
@@ -54,8 +54,8 @@
         super(Pipe, self).__init__()
         self._fd = None
         self._bytes = ""
-        self._reader = File()
-        self._writer = File()
+        self._reader = None
+        self._writer = None
         self._watchdog_client = None
         self._watchdog_server = None
 
@@ -71,11 +71,13 @@
 
     def connect(self, fd):
         self._fd = fd
-        return self._writer.initialize_from_fd(fd, "w") == 0
+        self._writer = create_file(fd, "w")
+        return self._writer is not None
 
     def listen(self, fd):
         self._fd = fd
-        return self._reader.initialize_from_fd(fd, "r") == 0
+        self._reader = create_file(fd, "r")
+        return self._reader is not None
 
     def handleIncomingMessage(self):
         """Receive messages from the reader and buffer them.

=== modified file 'checkbox/io/watchdog.py'
--- checkbox/io/watchdog.py	2012-04-23 19:36:19 +0000
+++ checkbox/io/watchdog.py	2012-05-02 10:18:20 +0000
@@ -28,7 +28,6 @@
 
 from checkbox.lib.fifo import fifo_create
 from checkbox.lib.file import (
-    File,
     fd_open,
     fd_close,
     )
@@ -88,8 +87,8 @@
 
     def __init__(self):
         self._path = None
-        self._reader = File()
-        self._writer = File()
+        self._reader = None
+        self._writer = None
 
     def __del__(self):
         self.reset()
@@ -108,7 +107,8 @@
             return False
 
         path += WATCHDOG_SUFFIX
-        if not fifo_create(path, self._reader, self._writer):
+        self._reader, self._writer = fifo_create(path)
+        if not self._reader or not self._writer:
             logging.info("Failed to set watched fifo path at %s", path)
             return False
 

=== modified file 'checkbox/journal/multi.py'
--- checkbox/journal/multi.py	2012-04-24 13:23:07 +0000
+++ checkbox/journal/multi.py	2012-05-02 10:18:20 +0000
@@ -30,7 +30,7 @@
 
 from checkbox.lib.directory import Directory
 from checkbox.lib.file import (
-    File,
+    create_file,
     fd_open,
     fd_close,
     )
@@ -74,7 +74,7 @@
 
         :param filename: Filename to read.
         """
-        file = File.create_from_path(filename, "r")
+        file = create_file(filename, "r")
         if not file:
             logging.debug(
                 "Failed to open '%s' with errno %d", filename, file.errno)
@@ -184,7 +184,7 @@
         if directory:
             submit_filename = os.path.join(directory, submit_filename)
 
-        file = File.create_from_path(submit_filename, "r")
+        file = create_file(submit_filename, "r")
         if not file:
             logging.debug(
                 "Failed to open '%s' with errno %d",

=== modified file 'checkbox/journal/reader.py'
--- checkbox/journal/reader.py	2012-04-23 19:36:19 +0000
+++ checkbox/journal/reader.py	2012-05-02 10:18:20 +0000
@@ -31,7 +31,7 @@
 from checkbox.lib import param
 from checkbox.lib.enum import Enum
 from checkbox.lib.file import (
-    File,
+    create_file,
     fd_open,
     fd_close,
     )
@@ -644,7 +644,7 @@
             return EventOutcome.READ_ERROR
 
         try:
-            self._file = File.create_from_fd(self._fd, "r")
+            self._file = create_file(self._fd, "r")
         except OSError:
             self._closeJournalFile(True)
             return EventOutcome.READ_ERROR

=== modified file 'checkbox/journal/tests/test_reader.py'
--- checkbox/journal/tests/test_reader.py	2012-04-23 19:36:19 +0000
+++ checkbox/journal/tests/test_reader.py	2012-05-02 10:18:20 +0000
@@ -26,7 +26,7 @@
 
 from tempfile import mkstemp
 
-from checkbox.lib.file import File
+from checkbox.lib.file import create_file
 
 from checkbox.journal.event import (
     Event,
@@ -45,7 +45,7 @@
 
     def setUp(self):
         (fd, self.path) = mkstemp()
-        self.file = File.create_from_fd(fd)
+        self.file = create_file(fd)
 
         os.environ["EVENT_JOURNAL"] = self.path
 

=== modified file 'checkbox/journal/tests/test_writer.py'
--- checkbox/journal/tests/test_writer.py	2012-04-23 19:36:19 +0000
+++ checkbox/journal/tests/test_writer.py	2012-05-02 10:18:20 +0000
@@ -27,7 +27,7 @@
 from tempfile import mkstemp
 from StringIO import StringIO
 
-from checkbox.lib.file import File
+from checkbox.lib.file import create_file
 
 from checkbox.journal.event import (
     Event,
@@ -40,7 +40,7 @@
 
     def setUp(self):
         (fd, self.path) = mkstemp()
-        self.file = File.create_from_fd(fd)
+        self.file = create_file(fd)
 
         os.environ["EVENT_JOURNAL"] = self.path
 

=== modified file 'checkbox/journal/writer.py'
--- checkbox/journal/writer.py	2012-04-23 19:36:19 +0000
+++ checkbox/journal/writer.py	2012-05-02 10:18:20 +0000
@@ -34,7 +34,7 @@
     )
 from checkbox.lib.file import (
     FILE_NULL,
-    File,
+    create_file,
     fd_open,
     fd_close,
     )
@@ -96,13 +96,13 @@
 
         self._user_enable = True
         self._path = ""
-        self._file = File()
+        self._file = None
         self._lock = Lock()
         self._enable_fsync = True
         self._enable_locking = True
 
         self._global_path = ""
-        self._global_file = File()
+        self._global_file = None
         self._global_lock = Lock()
         self._global_stat = None
 
@@ -186,12 +186,13 @@
         self._path = path
 
         # Reset local resources
-        self._file.reset()
+        self._file = None
         self._lock.reset()
 
-        if (self._user_enable
-            and not self._openPath(path, self._file, lock=self._lock)):
-            return False
+        if self._user_enable:
+            self._file = self._openPath(path, lock=self._lock)
+            if not self._file:
+                return False
 
         return self.initialize()
 
@@ -200,13 +201,14 @@
             self._global_lock.reset()
 
         if self._global_file:
-            self._global_file.reset()
+            self._global_file = None
 
         if not self._global_path:
             return True
 
-        if not self._openPath(
-            self._global_path, self._global_file, lock=self._global_lock):
+        self._global_file = self._openPath(
+            self._global_path, lock=self._global_lock)
+        if not self._global_file:
             return False
 
         stat = Stat()
@@ -290,7 +292,7 @@
         # Rotate the journal
 
         # Read the old header, use it to write an updated one
-        file = File.create_from_path(self._global_path, "r")
+        file = create_file(self._global_path, "r")
         if not file:
             logging.debug("Failed to open '%s'", self._global_path)
 
@@ -311,12 +313,11 @@
 
                 header_reader.num_events = events
 
-            file.reset()
-
         header_reader.size = current_filesize
 
         # Craft a header writer object from the header reader
-        if not self._openPath(self._global_path, file, False):
+        file = self._openPath(self._global_path, False)
+        if not file:
             logging.debug(
                 "Failed to open '%s' for header rewrite", self._global_path)
 
@@ -381,7 +382,7 @@
             return True
 
         # Reset global resources
-        self._global_file.reset()
+        self._global_file = None
         self._global_lock.reset()
         self._global_stat = None
 
@@ -430,9 +431,8 @@
 
         return True
 
-    def _openPath(self, path, file, append=True, lock=None):
+    def _openPath(self, path, append=True, lock=None):
         if path and path == FILE_NULL:
-            file.reset()
             if lock is not None:
                 lock.reset()
             return True
@@ -446,16 +446,15 @@
             return False
 
         mode = "a" if append else "w"
-        try:
-            file.initialize_from_fd(fd, mode)
-        except OSError:
-            fd_close(fd)
+        file = create_file(fd, mode)
+        if not file:
+            file.close()
             return False
 
         if lock is not None:
             lock.initialize(fd, file)
 
-        return True
+        return file
 
     def writeEvent(self, event):
         """Write an event to the journal file.

=== modified file 'checkbox/lib/fifo.py'
--- checkbox/lib/fifo.py	2012-04-23 19:36:19 +0000
+++ checkbox/lib/fifo.py	2012-05-02 10:18:20 +0000
@@ -30,13 +30,18 @@
 from checkbox.lib.file import (
     fd_open,
     fd_close,
+    create_file,
     )
 
 
 FIFO_BUF = 512
 
 
-def fifo_create(path, reader, writer):
+def fifo_create(path):
+    reader = None
+    writer = None
+    uninitialized_fh = reader, writer
+
     # Check that fifo doesn't exist
     if os.path.exists(path):
         os.unlink(path)
@@ -46,13 +51,18 @@
         os.mkfifo(path, 0600)
     except OSError, error:
         logging.info("Failed to create fifo %s: %d", path, error.errno)
-        return False
+        return uninitialized_fh
 
     # Open read side of the fifo initially in non-blocking mode
     read_fd = fd_open(path, os.O_RDONLY | os.O_NONBLOCK)
     if read_fd == -1:
         logging.info("Failed to open read-only %s", path)
-        return False
+        return uninitialized_fh
+    reader = create_file(read_fd, "r")
+    if not reader:
+        logging.info("Failed to initialize file descriptors.")
+        fd_close(read_fd)
+        return uninitialized_fh
 
     # Set the fifo back to blocking mode
     flags = fcntl.fcntl(read_fd, fcntl.F_GETFL)
@@ -63,14 +73,19 @@
     if write_fd == -1:
         logging.info("Failed to open write-only %s", path)
         fd_close(read_fd)
-        return False
-
-    if (reader.initialize_from_fd(read_fd, "r") or
-        writer.initialize_from_fd(write_fd, "w")):
+        return uninitialized_fh
+    writer = create_file(write_fd, "w")
+    if not writer:
         logging.info("Failed to initialize file descriptors.")
         fd_close(write_fd)
-        fd_close(read_fd)
-        return False
+        reader.close()
+        return uninitialized_fh
+
+    if (not reader.readable() or not writer.writable()):
+        logging.info("Failed to initialize file descriptors.")
+        writer.close()
+        reader.close()
+        return uninitialized_fh
 
     # Everything worked
-    return True
+    return reader, writer

=== modified file 'checkbox/lib/file.py'
--- checkbox/lib/file.py	2012-04-23 19:36:19 +0000
+++ checkbox/lib/file.py	2012-05-02 10:18:20 +0000
@@ -21,6 +21,7 @@
 __all__ = [
     "FILE_NULL",
     "File",
+    "create_file",
     "fd_open",
     "fd_close",
     "fd_get_flags",
@@ -28,92 +29,33 @@
     ]
 
 import os
+import io
 import fcntl
 
-from checkbox.lib.decorators import CheckException
-
 
 FILE_NULL = "/dev/null"
 
 
-class CheckError(CheckException):
-
-    def onError(self, error):
-        self._instance.errno = error.errno
-
-
-def check_error(default=None):
-
-    def wrapper(func):
-        return CheckError(func, default, EnvironmentError)
-
-    return wrapper
-
-
-class File:
-
-    __slots__ = (
-        "info",
-        "errno",
-        )
-
-    def __init__(self):
-        self.info = None
-        self.errno = 0
-
-    @classmethod
-    def create_from_path(cls, *args, **kwargs):
-        file = cls()
-        file.initialize_from_path(*args, **kwargs)
-
-        return file
-
-    @classmethod
-    def create_from_fd(cls, *args, **kwargs):
-        file = cls()
-        file.initialize_from_fd(*args, **kwargs)
-
-        return file
-
-    @check_error(-1)
-    def initialize_from_path(self, *args, **kwargs):
-        self.info = open(*args, **kwargs)
-        return 0
-
-    @check_error(-1)
-    def initialize_from_fd(self, *args, **kwargs):
-        self.info = os.fdopen(*args, **kwargs)
-        return 0
-
-    def copy_from(self, other):
-        self.info = other.info
-
-    def reset(self):
-        self.info = None
-        self.errno = 0
-
-    @check_error(None)
+class File(io.FileIO):
+
     def read(self, size):
-        # Return something useful
-        return os.read(self.info.fileno(), size)
+        try:
+            return super(File, self).read(size)
+        except (EnvironmentError, ValueError):
+            return None
 
-    @check_error(-1)
     def write(self, buffer):
-        # Return something useful
-        return os.write(self.info.fileno(), buffer)
-
-    @check_error(None)
-    def __getattr__(self, name):
-        return getattr(self.info, name)
-
-    def __setattr__(self, name, value):
-        if name in File.__slots__:
-            return super(File, self).__setattr__(name, value)
-
-        return setattr(self.info, name, value)
-
-    def __nonzero__(self):
-        return self.info is not None
+        try:
+            return super(File, self).write(buffer)
+        except (EnvironmentError, ValueError):
+            return -1
+
+
+def create_file(*args, **kwargs):
+    try:
+        return File(*args, **kwargs)
+    except (EnvironmentError, ValueError):
+        return None
 
 
 def fd_open(path, flag, *args, **kwargs):

=== modified file 'checkbox/lib/tests/test_fifo.py'
--- checkbox/lib/tests/test_fifo.py	2012-04-23 19:36:19 +0000
+++ checkbox/lib/tests/test_fifo.py	2012-05-02 10:18:20 +0000
@@ -26,7 +26,6 @@
 from unittest import TestCase
 
 from checkbox.lib.fifo import fifo_create
-from checkbox.lib.file import File
 
 
 class TestFifo(TestCase):
@@ -39,9 +38,6 @@
             os.unlink(self.path)
 
     def test_fifo_create(self):
-        read_file = File()
-        write_file = File()
-
-        self.assertTrue(fifo_create(self.path, read_file, write_file))
-        self.assertNotEquals(read_file.fileno(), -1)
-        self.assertNotEquals(write_file.fileno(), -1)
+        reader, writer = fifo_create(self.path)
+        self.assertNotEquals(reader.fileno(), -1)
+        self.assertNotEquals(writer.fileno(), -1)

=== modified file 'checkbox/lib/tests/test_file.py'
--- checkbox/lib/tests/test_file.py	2012-04-23 19:36:19 +0000
+++ checkbox/lib/tests/test_file.py	2012-05-02 10:18:20 +0000
@@ -21,6 +21,7 @@
 __all__ = []
 
 import os
+from io import (SEEK_SET, SEEK_CUR)
 
 from unittest import TestCase
 
@@ -30,7 +31,7 @@
     )
 
 from checkbox.lib.file import (
-    File,
+    create_file,
     fd_open,
     fd_close,
     )
@@ -46,40 +47,15 @@
         if os.path.exists(self.path):
             os.unlink(self.path)
 
-    def test_init(self):
-        file = File()
-        self.assertFalse(file)
-
-    def test_create_from_path(self):
-        file = File.create_from_path(self.path)
-        self.assertEquals(file.errno, 0)
-        self.assertTrue(file)
-
-        file = File.create_from_path(self.temp)
-        self.assertEquals(file.errno, 2)
-        self.assertFalse(file)
-
-    def test_initialize_from_fd(self):
-        file = File.create_from_fd(self.fd)
-        self.assertEquals(file.errno, 0)
-        self.assertTrue(file)
-
-        file = File.create_from_fd(-1)
-        self.assertEquals(file.errno, 9)
-        self.assertFalse(file)
-
-    def test_reset(self):
-        file = File.create_from_path(self.path)
-        self.assertTrue(file)
-
-        file.reset()
-        self.assertFalse(file)
-
-        file = File.create_from_path(self.temp)
-        self.assertEquals(file.errno, 2)
-
-        file.reset()
-        self.assertEquals(file.errno, 0)
+    def test_create_file(self):
+        file = create_file(self.path)
+        self.assertTrue(file)
+
+        file = create_file(self.temp)
+        self.assertFalse(file)
+
+        file = create_file(0xFFFF)
+        self.assertFalse(file)
 
     def test_fd_open(self):
         fd = fd_open(self.path, os.O_RDONLY)
@@ -94,3 +70,30 @@
 
         ret = fd_close(-1)
         self.assertEquals(ret, -1)
+
+    def test_tell_seek(self):
+        file = create_file(self.fd, 'w')
+        self.assertTrue(file)
+
+        self.assertEquals(file.tell(), 0)
+        pos = file.write('ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890')
+        self.assertEquals(pos, 36)
+        self.assertEquals(file.tell(), 36)
+        file.close()
+
+        file = create_file(self.path)
+        self.assertTrue(file)
+
+        self.assertEquals(file.tell(), 0)
+        str = file.read(4)
+        self.assertEquals(str, 'ABCD')
+        self.assertEquals(file.tell(), 4)
+
+        file.seek(14, SEEK_CUR)
+        self.assertEquals(file.tell(), 18)
+
+        os.lseek(file.fileno(), 28, SEEK_SET)
+        self.assertEquals(file.tell(), 28)
+        str = file.read(1)
+        self.assertEquals(str, '3')
+        self.assertEquals(file.tell(), 29)

=== modified file 'checkbox/runner/manager.py'
--- checkbox/runner/manager.py	2012-04-23 19:36:19 +0000
+++ checkbox/runner/manager.py	2012-05-02 10:18:20 +0000
@@ -26,7 +26,7 @@
 import logging
 
 from checkbox.lib import param
-from checkbox.lib.file import File
+from checkbox.lib.file import create_file
 
 from checkbox.daemon.server import server
 
@@ -214,9 +214,9 @@
 
         if self._output_record_is_stdout:
             logging.info("Will write output record to STDOUT")
-            file = File.create_from_fd(1)
+            file = create_file(1)
         else:
-            file = File.create_from_path(self._output_record_path, "a")
+            file = create_file(self._output_record_path, "a")
             if not file:
                 logging.info(
                     "Failed to open output record '%s': %s",

=== modified file 'checkbox/runner/starter.py'
--- checkbox/runner/starter.py	2012-04-23 19:36:19 +0000
+++ checkbox/runner/starter.py	2012-05-02 10:18:20 +0000
@@ -30,7 +30,7 @@
 
 from checkbox.lib import param
 from checkbox.lib.enum import Enum
-from checkbox.lib.file import File
+from checkbox.lib.file import create_file
 
 from checkbox.daemon.server import (
     server,
@@ -190,7 +190,7 @@
                 self._execute_directory, "%d.recover" % server.pid)
 
         tmp_path = "%s.tmp" % self._recovery_path
-        tmp_file = File.create_from_path(tmp_path, "w")
+        tmp_file = create_file(tmp_path, "w")
         if not tmp_file:
             logging.info("Failed to open recovery file %s", tmp_path)
             return