"""Benchmark bsonjs (libbson) vs bson.json_util (pymongo)."""
import timeit
import bsonjs
import bson
from bson import json_util

doc = {
    '_id': bson.ObjectId(),
    'string': 's'*20000
}
b = bson.encode(doc)
j = json_util.dumps(doc)

def time(fn, iterations=25):
    print('Timing: ' + fn.__name__)
    best = min(timeit.Timer(fn).repeat(5, number=iterations))
    print('{0} loops, best of 5: {1}'.format(iterations, best))
    return best

def compare(bsonjs_stmt, json_util_stmt):
    bsonjs_secs = time(bsonjs_stmt)
    json_util_secs = time(json_util_stmt)
    print('bsonjs is {0:.2f}x faster than json_util\n'.format(
        json_util_secs/bsonjs_secs))

def dumps_bsonjs():
    bsonjs.dumps(b)

def dumps_json_util():
    json_util.dumps(bson.decode(b))

def loads_bsonjs():
    bsonjs.loads(j)

def loads_json_util():
    bson.encode(json_util.loads(j))

def main():
    compare(dumps_bsonjs, dumps_json_util)
    compare(loads_bsonjs, loads_json_util)

if __name__ == "__main__":
    main()

$ python3.10 benchmark_str_perf.py
Timing: dumps_bsonjs
25 loops, best of 5: 0.00783308400423266
Timing: dumps_json_util
25 loops, best of 5: 0.002030832998570986
bsonjs is 0.26x faster than json_util

Timing: loads_bsonjs
25 loops, best of 5: 0.001949673009221442
Timing: loads_json_util
25 loops, best of 5: 0.000629648013273254
bsonjs is 0.32x faster than json_util

doc = {
    '_id': bson.ObjectId(),
    'string': 's'*10,
    'foo': [1, 2],
    'bar': {'hello': 'world'},
    'date': datetime.datetime(2009, 12, 9, 15),
}
...
$ python3.10 benchmark_str_perf.py
Timing: dumps_bsonjs
25 loops, best of 5: 0.00018512399401515722
Timing: dumps_json_util
25 loops, best of 5: 0.001294998000958003
bsonjs is 7.00x faster than json_util

Timing: loads_bsonjs
25 loops, best of 5: 0.00016003800556063652
Timing: loads_json_util
25 loops, best of 5: 0.0011928190069738775
bsonjs is 7.45x faster than json_util