add memory usage tests

tests/python/tests/memory/php/data/component-config.yaml

@@ -0,0 +1,7 @@
+entry: script
+components:
+  script:
+    image: KPHP
+    scope: Request
+    args: {}
+    links: {}

tests/python/tests/memory/php/index.php

@@ -0,0 +1,66 @@
+<?php
+
+$res = [];
+
+$a = "";
+
+function memory_work($n) {
+  global $a;
+
+  for ($i = 1; $i <= $n; ++$i) {
+    $a .= "a";
+  }
+}
+
+function test_memory_usage() {
+  global $res, $a;
+
+  $base_usage = memory_get_usage(false);
+
+  memory_work(1e6);  # 1 MB allocation expected
+
+  $usage = memory_get_usage(false) - $base_usage;
+
+  $a = "";
+
+  $usage_after_cleaning = memory_get_usage(false) - $base_usage;
+  $peak_usage = memory_get_peak_usage(false) - $base_usage;
+
+  $res["usage"] = $usage;
+  $res["usage_after_cleaning"] = $usage_after_cleaning;
+  $res["peak_usage"] = $peak_usage;
+}
+
+function test_total_memory_usage() {
+  global $res, $a;
+
+  memory_work(2048);  # memory usage for small pieces depends on runtime
+
+  $base_usage = memory_get_total_usage();
+
+  memory_work(1e6);  # 1 MB allocation expected
+
+  $usage = memory_get_total_usage() - $base_usage;
+
+  $a = "";
+
+  $usage_after_cleaning = memory_get_total_usage() - $base_usage;
+  $peak_usage = memory_get_peak_usage(true) - $base_usage;
+
+  $res["usage"] = $usage;
+  $res["usage_after_cleaning"] = $usage_after_cleaning;
+  $res["peak_usage"] = $peak_usage;
+}
+
+switch($_SERVER["PHP_SELF"]) {
+  case "/test_memory_usage":
+    test_memory_usage();
+    break;
+  case "/test_total_memory_usage":
+    test_total_memory_usage();
+    break;
+  default:
+    critical_error('unexpected "' . $_SERVER["PHP_SELF"] . '"');
+}
+
+echo json_encode($res);

tests/python/tests/memory/test_memory_stats.py

@@ -0,0 +1,35 @@
+from python.lib.testcase import WebServerAutoTestCase
+
+
+class TestMemoryUsage(WebServerAutoTestCase):
+    STRING_ALIGNMENT = 4096
+    MAX_ALLOCATION_SIZE = 2**20   # 1 MB
+
+    def _template(self, test_case: str, expected_usage: int, expected_usage_after_cleaning: int, expected_peak_usage: int):
+        response = self.web_server.http_post(f"/{test_case}")
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(
+            response.json(),
+            {
+                "usage": expected_usage,
+                "usage_after_cleaning": expected_usage_after_cleaning,
+                "peak_usage": expected_peak_usage,
+            },
+        )
+
+    def test_memory_usage(self):
+        self._template(
+            "test_memory_usage",
+            expected_usage=self.MAX_ALLOCATION_SIZE,
+            expected_usage_after_cleaning=0,
+            expected_peak_usage=self.MAX_ALLOCATION_SIZE +    # last allocation size
+            self.MAX_ALLOCATION_SIZE // 2                     # prev allocation size
+        )
+
+    def test_total_memory_usage(self):
+        self._template(
+            "test_total_memory_usage",
+            expected_usage=2 * self.MAX_ALLOCATION_SIZE - 2 * self.STRING_ALIGNMENT,              # 8192 + 16384 + ... + 2**20
+            expected_usage_after_cleaning=self.MAX_ALLOCATION_SIZE - 2 * self.STRING_ALIGNMENT,   # 8192 + 16384 + ... + 2**19
+            expected_peak_usage=2 * self.MAX_ALLOCATION_SIZE - 2 * self.STRING_ALIGNMENT,         # 8192 + 16384 + ... + 2**20
+        )