1 files changed, 116 insertions, 0 deletions
diff --git a/third_party/python/dlmanager/dlmanager/fs.py b/third_party/python/dlmanager/dlmanager/fs.py
new file mode 100644
index 0000000000..8908b5efce
--- /dev/null
+++ b/third_party/python/dlmanager/dlmanager/fs.py
@@ -0,0 +1,116 @@
+import errno
+import logging
+import os
+import shutil
+import stat
+import time
+
+"""
+File system utilities, copied from mozfile.
+"""
+
+LOG = logging.getLogger(__name__)
+
+
+def _call_windows_retry(func, args=(), retry_max=5, retry_delay=0.5):
+    """
+    It's possible to see spurious errors on Windows due to various things
+    keeping a handle to the directory open (explorer, virus scanners, etc)
+    So we try a few times if it fails with a known error.
+    """
+    retry_count = 0
+    while True:
+        try:
+            func(*args)
+        except OSError as e:
+            # Error codes are defined in:
+            # http://docs.python.org/2/library/errno.html#module-errno
+            if e.errno not in (errno.EACCES, errno.ENOTEMPTY):
+                raise
+
+            if retry_count == retry_max:
+                raise
+
+            retry_count += 1
+
+            LOG.info('%s() failed for "%s". Reason: %s (%s). Retrying...',
+                     func.__name__, args, e.strerror, e.errno)
+            time.sleep(retry_delay)
+        else:
+            # If no exception has been thrown it should be done
+            break
+
+
+def remove(path):
+    """Removes the specified file, link, or directory tree.
+
+    This is a replacement for shutil.rmtree that works better under
+    windows. It does the following things:
+
+     - check path access for the current user before trying to remove
+     - retry operations on some known errors due to various things keeping
+       a handle on file paths - like explorer, virus scanners, etc. The
+       known errors are errno.EACCES and errno.ENOTEMPTY, and it will
+       retry up to 5 five times with a delay of 0.5 seconds between each
+       attempt.
+
+    Note that no error will be raised if the given path does not exists.
+
+    :param path: path to be removed
+    """
+
+    def _call_with_windows_retry(*args, **kwargs):
+        try:
+            _call_windows_retry(*args, **kwargs)
+        except OSError as e:
+            # The file or directory to be removed doesn't exist anymore
+            if e.errno != errno.ENOENT:
+                raise
+
+    def _update_permissions(path):
+        """Sets specified pemissions depending on filetype"""
+        if os.path.islink(path):
+            # Path is a symlink which we don't have to modify
+            # because it should already have all the needed permissions
+            return
+
+        stats = os.stat(path)
+
+        if os.path.isfile(path):
+            mode = stats.st_mode | stat.S_IWUSR
+        elif os.path.isdir(path):
+            mode = stats.st_mode | stat.S_IWUSR | stat.S_IXUSR
+        else:
+            # Not supported type
+            return
+
+        _call_with_windows_retry(os.chmod, (path, mode))
+
+    if not os.path.exists(path):
+        return
+
+    if os.path.isfile(path) or os.path.islink(path):
+        # Verify the file or link is read/write for the current user
+        _update_permissions(path)
+        _call_with_windows_retry(os.remove, (path,))
+
+    elif os.path.isdir(path):
+        # Verify the directory is read/write/execute for the current user
+        _update_permissions(path)
+
+        # We're ensuring that every nested item has writable permission.
+        for root, dirs, files in os.walk(path):
+            for entry in dirs + files:
+                _update_permissions(os.path.join(root, entry))
+        _call_with_windows_retry(shutil.rmtree, (path,))
+
+
+def move(src, dst):
+    """
+    Move a file or directory path.
+
+    This is a replacement for shutil.move that works better under windows,
+    retrying operations on some known errors due to various things keeping
+    a handle on file paths.
+    """
+    _call_windows_retry(shutil.move, (src, dst))