add stress_test.py

1 files changed, 112 insertions, 0 deletions

diff --git a/test/stress_test.py b/test/stress_test.py
new file mode 100644
index 0000000..e7386fd
--- /dev/null
+++ b/test/stress_test.py
@@ -0,0 +1,112 @@
+import argparse
+import ast
+from contextlib import contextmanager
+import math
+from multiprocessing import Pool
+import random
+import subprocess
+import sys
+from timeit import default_timer
+
+# This is a crappy script to feed the server with somewhat random arithmetic
+# expressions.
+# It's throwaway, hence the poor quality.
+
+DEFAULT_CLIENT_PATH = 'client'
+DEFAULT_HOST = 'localhost'
+DEFAULT_PORT = 18000
+
+class Client:
+    def __init__(self, path=DEFAULT_CLIENT_PATH, host=DEFAULT_HOST, port=DEFAULT_PORT):
+        self._path = path
+        self._host = host
+        self._port = port
+
+    def get_command_line(self):
+        return [self._path, '--host', self._host, '--port', str(self._port)]
+
+@contextmanager
+def timer(description):
+    start = default_timer()
+    yield
+    duration = default_timer() - start
+    print(f"{description}: {duration}")
+
+def run_client(i, client, stdin):
+    with timer(f"Invocation #{i}"):
+        cmd = client.get_command_line()
+        return subprocess.run(cmd, text=True, input=stdin, capture_output=True)
+
+OPERATORS = '+', '-', '*', '/'
+MIN_OPERATORS = 10
+MAX_OPERATORS = 1000
+MIN_NUMBER = -10e10
+MAX_NUMBER = 10e10
+
+def random_operator():
+    return OPERATORS[random.randrange(len(OPERATORS))]
+
+def random_number():
+    return random.randint(MIN_NUMBER, MAX_NUMBER)
+
+def gen_expression():
+    numof_operators = random.randrange(MIN_OPERATORS, MAX_OPERATORS + 1)
+    expression = ''
+    for i in range(numof_operators):
+        expression += f"{random_number()} {random_operator()} "
+    expression += str(random_number())
+    return expression
+
+def gen_expressions(n):
+    for i in range(n):
+        yield gen_expression()
+
+def run_stress_test(args):
+    client = Client(args.client, args.host, args.port)
+    expressions = list(gen_expressions(args.expressions))
+    stdin = '\n'.join(expressions)
+    expected_output = [eval(expr) for expr in expressions]
+    with Pool(args.processes) as pool:
+        results = pool.starmap(run_client, [(i, client, stdin) for i in range(args.processes)])
+        assert results
+        # It's assumed every invocation gives the same output, yikes.
+        actual_output = list(map(float, results[0].stdout.split('\n\n')[:-1]))
+        assert len(expected_output) == len(actual_output)
+        for i in range(len(expected_output)):
+            if math.isclose(expected_output[i], actual_output[i]):
+                continue
+            print(f"Expression: {expressions[i]}")
+            print(f"Expected output: {expected_output[i]}")
+            print(f"Actual output:   {actual_output[i]}")
+
+def parse_args(argv=None):
+    if argv is None:
+        argv = sys.argv[1:]
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--host', '-H', metavar='HOST',
+                        default=DEFAULT_HOST,
+                        help='set host')
+    parser.add_argument('--port', '-p', metavar='PORT',
+                        type=int, default=DEFAULT_PORT,
+                        help='set port')
+    parser.add_argument('--processes', '-n', metavar='N',
+                        type=int, default=1,
+                        help='set number of processes')
+    parser.add_argument('--expressions', '-e', metavar='N',
+                        type=int, default=1,
+                        help='set number of expressions')
+    parser.add_argument('--client', '-c', metavar='PATH',
+                        default=DEFAULT_CLIENT_PATH,
+                        help='set path to client.exe')
+    args = parser.parse_args(argv)
+    # Bleh
+    assert args.processes > 0
+    assert args.expressions > 0
+    return args
+
+def main(argv=None):
+    args = parse_args(argv)
+    run_stress_test(args)
+
+if __name__ == '__main__':
+    main()