1 files changed, 110 insertions, 0 deletions
diff --git a/lava/helper/dispatcher.py b/lava/helper/dispatcher.py
new file mode 100644
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+++ b/lava/helper/dispatcher.py
@@ -0,0 +1,110 @@
+# Copyright (C) 2013 Linaro Limited
+#
+# Author: Milo Casagrande <milo.casagrande@linaro.org>
+#
+# This file is part of lava-tool.
+#
+# lava-tool is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License version 3
+# as published by the Free Software Foundation
+#
+# lava-tool is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with lava-tool.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Classes and functions to interact with the lava-dispatcher."""
+
+import random
+import string
+import os
+
+from lava.tool.errors import CommandError
+
+# Default devices path, has to be joined with the dispatcher path.
+DEFAULT_DEVICES_PATH = "devices"
+
+
+def get_dispatcher_paths():
+    """Tries to get the dispatcher paths from lava-dispatcher.
+
+    :return A list of paths.
+    """
+    try:
+        from lava_dispatcher.config import write_path
+        return write_path()
+    except ImportError:
+        raise CommandError("Cannot find lava-dispatcher installation.")
+
+
+def get_devices():
+    """Gets the devices list from the dispatcher.
+
+    :return A list of DeviceConfig.
+    """
+    try:
+        from lava_dispatcher.config import get_devices
+        return get_devices()
+    except ImportError:
+        raise CommandError("Cannot find lava-dispatcher installation.")
+
+
+def get_device_file(file_name):
+    """Retrieves the config file name specified, if it exists.
+
+    :param file_name: The config file name to search.
+    :return The path to the file, or None if it does not exist.
+    """
+    try:
+        from lava_dispatcher.config import get_config_file
+        return get_config_file(os.path.join(DEFAULT_DEVICES_PATH,
+                                            file_name))
+    except ImportError:
+        raise CommandError("Cannot find lava-dispatcher installation.")
+
+
+def choose_devices_path(paths):
+    """Picks the first path that is writable by the user.
+
+    :param paths: A list of paths.
+    :return The first path where it is possible to write.
+    """
+    valid_path = None
+    for path in paths:
+        path = os.path.join(path, DEFAULT_DEVICES_PATH)
+        if os.path.exists(path):
+            name = "".join(random.choice(string.ascii_letters)
+                           for x in range(6))
+            test_file = os.path.join(path, name)
+            try:
+                fp = open(test_file, 'a')
+                fp.close()
+            except IOError:
+                # Cannot write here.
+                continue
+            else:
+                valid_path = path
+                if os.path.isfile(test_file):
+                    os.unlink(test_file)
+                break
+        else:
+            try:
+                os.makedirs(path)
+            except OSError:
+                # Cannot write here either.
+                continue
+            else:
+                valid_path = path
+                break
+    else:
+        raise CommandError("Insufficient permissions to create new "
+                           "devices.")
+    return valid_path
+
+
+def get_devices_path():
+    """Gets the path to the devices in the LAVA dispatcher."""
+    return choose_devices_path(get_dispatcher_paths())