params: code cleanup (#22744)

* cleanup params

* apply review

* continue

* use c_str

* cleanup filelock

* don't check return code of close()

* remove call_once

* cleanup params_pyx

* cleanup comment
old-commit-hash: 2773ff5aceb8874a9319c819ec3707705a00604d

common/params_pyx.pyx

@@ -14,7 +14,6 @@ cdef extern from "selfdrive/common/params.h":
     ALL
 
   cdef cppclass c_Params "Params":
-    c_Params() nogil
     c_Params(string) nogil
     string get(string, bool) nogil
     bool getBool(string) nogil
@@ -34,36 +33,25 @@ class UnknownKeyName(Exception):
 cdef class Params:
   cdef c_Params* p
 
-  def __cinit__(self, d=None):
-    cdef string path
-    if d is None:
-      with nogil:
-        self.p = new c_Params()
-    else:
-      path = <string>d.encode()
-      with nogil:
-        self.p = new c_Params(path)
+  def __cinit__(self, d=""):
+    cdef string path = <string>d.encode()
+    with nogil:
+      self.p = new c_Params(path)
 
   def __dealloc__(self):
     del self.p
 
-  def clear_all(self, tx_type=None):
-    if tx_type is None:
-      tx_type = ParamKeyType.ALL
-
+  def clear_all(self, tx_type=ParamKeyType.ALL):
     self.p.clearAll(tx_type)
 
   def check_key(self, key):
     key = ensure_bytes(key)
-
     if not self.p.checkKey(key):
       raise UnknownKeyName(key)
-
     return key
 
   def get(self, key, bool block=False, encoding=None):
     cdef string k = self.check_key(key)
-
     cdef string val
     with nogil:
       val = self.p.get(k, block)
@@ -76,10 +64,7 @@ cdef class Params:
       else:
         return None
 
-    if encoding is not None:
-      return val.decode(encoding)
-    else:
-      return val
+    return val if encoding is None else val.decode(encoding)
 
   def get_bool(self, key):
     cdef string k = self.check_key(key)
@@ -110,8 +95,7 @@ cdef class Params:
     with nogil:
       self.p.remove(k)
 
-
-def put_nonblocking(key, val, d=None):
+def put_nonblocking(key, val, d=""):
   def f(key, val):
     params = Params(d)
     cdef string k = ensure_bytes(key)