#%%
import gc
from typing import Any
from pymongo import MongoClient
from bson.codec_options import CodecOptions
from bson.codec_options import TypeCodec, TypeRegistry

#%% Define method to analyse the memory
def memory_report():
    gc.collect()
    rr={}
    for obj in gc.get_objects():

        tt=type(obj)
        if 'bson' in str(tt):
            rr[tt] = rr.get(tt, 0)+1

    print('memory report:')
    for key in rr:
        nn=rr[key]
        print(f' {key}: {nn}')


#%% Create codec

class MyClass:
    pass

class MyCodec(TypeCodec):  # type: ignore

    pass
    @property
    def python_type(self) -> Any:
         return MyClass

    def transform_python(self, value: Any) -> Any:
        #print(f'transform_python: {value}')
        return value

    @property
    def bson_type(self) -> Any:
         return dict

    def transform_bson(self, value: Any) -> Any:
         #print(f'transform_bson: {value}')
         return value
    
codec=MyCodec()
type_registry = TypeRegistry([codec]) 
codec_options = CodecOptions(type_registry=type_registry) 

client = MongoClient('localhost:27017')
database = client['my_database']
collection = database['my_collection'].with_options(codec_options)

for ii in range(3000):
    cursor = collection.find({})
    for data in cursor:
        pass

_=memory_report() # for multiple iterations objects of type bson.codec_options.CodecOptions are leaking