1_instructions.rst

1. $ git clone https://github.com/MagicStack/immutables.git
2. cd immutables
3. wget https://gist.githubusercontent.com/1st1/57d979e1e58948a7e523754a3d02a57d/raw/8857aca8e0f13c804218540820993b6481cd6619/bench.py
4. pypy3 bench.py -- observe the timings for "hamt"
5. run pypy3 bench.py -- observe how "hamt" timings are way worse now
6. find . -name '*.pyc' | xargs rm
7. run pypy3 bench.py -- observe how "hamt" timings are low again

bench.py

import immutables
import time

I = 1000000
KEY = '5'


for N in [5, 10, 20, 30, 100, 200, 300, 400, 500, 1000]:
    print('=============')
    print(f'  # of items: {N}; iterations: {I}')
    print()


    h = immutables.Map()
    d = dict()

    for i in range(N):
        h = h.set(str(i), i)
        d[str(i)] = i

    assert len(h) == N

    for i in range(N):
        assert h.get(str(i), 'not found') == i


    st = time.monotonic()
    for _ in range(I):
        d.get(KEY)
        d.get(KEY)
        d.get(KEY)
        d.get(KEY)
        d.get(KEY)

        d.get(KEY)
        d.get(KEY)
        d.get(KEY)
        d.get(KEY)
        d.get(KEY)

        d2 = d.copy()
        d2['aaa'] = 'aaa'

    end = time.monotonic() - st
    print(f"  dict copy:\t\t\t{end:.4f}s")


    st = time.monotonic()
    for _ in range(I):
        h.get(KEY)
        h.get(KEY)
        h.get(KEY)
        h.get(KEY)
        h.get(KEY)

        h.get(KEY)
        h.get(KEY)
        h.get(KEY)
        h.get(KEY)
        h.get(KEY)

        h2 = h.set('aaa', 'aaa')

    end = time.monotonic() - st
    print(f"  hamt:\t\t\t\t{end:.4f}s")

my_outs.md

first run

=============
  # of items: 5; iterations: 1000000

  dict copy:			0.1487s
  hamt:				0.6501s
=============
  # of items: 10; iterations: 1000000

  dict copy:			0.3177s
  hamt:				0.6005s
=============
  # of items: 20; iterations: 1000000

  dict copy:			0.4995s
  hamt:				0.7768s
=============
  # of items: 30; iterations: 1000000

  dict copy:			0.6714s
  hamt:				0.9609s
=============
  # of items: 100; iterations: 1000000

  dict copy:			2.2390s
  hamt:				0.9238s
=============

[etc]

second run

=============
  # of items: 5; iterations: 1000000

  dict copy:			0.1543s
  hamt:				3.9164s
=============
  # of items: 10; iterations: 1000000

  dict copy:			0.3109s
  hamt:				6.4567s
=============
  # of items: 20; iterations: 1000000

  dict copy:			0.4718s
  hamt:				6.6128s
=============
[etc]

pypy3 --version

Python 3.5.3 (3f6eaa010fce, Jan 11 2018, 05:27:47)
[PyPy 5.10.1 with GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.39.2)]

More details:

I'm running this all under pypy3 venv created with pypy3 -m venv test.