From cbb46e426b5e88d34a6a38b2132b222bd3b896a4 Mon Sep 17 00:00:00 2001
From: judyjoseph <53951155+judyjoseph@users.noreply.github.com>
Date: Sat, 22 Aug 2020 16:24:44 -0700
Subject: [PATCH] Add common functions applicable to single/multi asic
 platforms (#5224)

* Add common functions applicable to single/multi asic platforms
* Raise exception if invalid namespace is given as input.
---
 .../sonic_py_common/multi_asic.py             | 38 ++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/src/sonic-py-common/sonic_py_common/multi_asic.py b/src/sonic-py-common/sonic_py_common/multi_asic.py
index 2083e3935b..78bc6d72ba 100644
--- a/src/sonic-py-common/sonic_py_common/multi_asic.py
+++ b/src/sonic-py-common/sonic_py_common/multi_asic.py
@@ -123,11 +123,17 @@ def is_multi_asic():
 
 
 def get_asic_id_from_name(asic_name):
+    """
+    Get the asic id from the asic name for multi-asic platforms
+    In single ASIC platforms, it would fail and throw an exception.
 
+    Returns:
+        asic id.
+    """
     if asic_name.startswith(ASIC_NAME_PREFIX):
         return asic_name[len(ASIC_NAME_PREFIX):]
     else:
-        return None
+        raise ValueError('Unknown asic namespace name {}'.format(asic_name))
 
 
 def get_namespaces_from_linux():
@@ -308,3 +314,33 @@ def is_bgp_session_internal(bgp_neigh_ip, namespace=None):
         else:
             return False
     return False
+
+def get_front_end_namespaces():
+    """
+    Get the namespaces in the platform. For multi-asic devices we get the namespaces
+    mapped to asic which have front-panel interfaces. For single ASIC device it is the
+    DEFAULT_NAMESPACE which maps to the linux host.
+
+    Returns:
+        a list of namespaces
+    """
+    namespaces = [DEFAULT_NAMESPACE]
+    if is_multi_asic():
+        ns_list = get_all_namespaces()
+        namespaces = ns_list['front_ns']
+
+    return namespaces
+
+
+def get_asic_index_from_namespace(namespace):
+    """
+    Get asic index from the namespace name.
+    With single ASIC platform, return asic_index 0, which is mapped to the only asic present.
+
+    Returns:
+        asic_index as an integer.
+    """
+    if is_multi_asic():
+        return int(get_asic_id_from_name(namespace))
+
+    return 0