Fixed app restart on Android 10, Python output redirect to logcat

src/serious_python/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.9.7
+
+* Fix app restart on Android 10.
+* Redirect Python output to logcat.
+
 ## 0.9.6
 
 * Make zipDirectory call asynchronous.

src/serious_python/pubspec.yaml

@@ -2,7 +2,7 @@ name: serious_python
 description: A cross-platform plugin for adding embedded Python runtime to your Flutter apps.
 homepage: https://flet.dev
 repository: https://github.com/flet-dev/serious-python
-version: 0.9.6
+version: 0.9.7
 
 platforms:
   ios:

src/serious_python_android/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.9.7
+
+* Fix app restart on Android 10.
+* Redirect Python output to logcat.
+
 ## 0.9.6
 
 * Make zipDirectory call asynchronous.

src/serious_python_android/android/build.gradle

@@ -1,5 +1,5 @@
 group 'com.flet.serious_python_android'
-version '0.9.6'
+version '0.9.7'
 
 def python_version = '3.12'
 

src/serious_python_android/lib/serious_python_android.dart

@@ -8,6 +8,7 @@ import 'package:path/path.dart' as p;
 import 'package:serious_python_platform_interface/serious_python_platform_interface.dart';
 
 import 'src/cpython.dart';
+import 'src/log.dart';
 
 /// An implementation of [SeriousPythonPlatform] that uses method channels.
 class SeriousPythonAndroid extends SeriousPythonPlatform {
@@ -33,24 +34,23 @@ class SeriousPythonAndroid extends SeriousPythonPlatform {
       List<String>? modulePaths,
       Map<String, String>? environmentVariables,
       bool? sync}) async {
-    Future setenv(String key, String value) async {
-      await methodChannel.invokeMethod<String>(
-          'setEnvironmentVariable', {'name': key, 'value': value});
-    }
+    Future<void> setenv(String key, String value) =>
+        methodChannel.invokeMethod<String>(
+            'setEnvironmentVariable', {'name': key, 'value': value});
 
     // load libpyjni.so to get JNI reference
     try {
       await methodChannel
           .invokeMethod<String>('loadLibrary', {'libname': 'pyjni'});
       await setenv("FLET_JNI_READY", "1");
     } catch (e) {
-      debugPrint("Warning: Unable to load libpyjni.so library: $e");
+      spDebug("Unable to load libpyjni.so library: $e");
     }
 
     // unpack python bundle
     final nativeLibraryDir =
         await methodChannel.invokeMethod<String>('getNativeLibraryDir');
-    debugPrint("getNativeLibraryDir: $nativeLibraryDir");
+    spDebug("getNativeLibraryDir: $nativeLibraryDir");
 
     var bundlePath = "$nativeLibraryDir/libpythonbundle.so";
     var sitePackagesZipPath = "$nativeLibraryDir/libpythonsitepackages.so";
@@ -60,7 +60,7 @@ class SeriousPythonAndroid extends SeriousPythonPlatform {
     }
     var pythonLibPath =
         await extractFileZip(bundlePath, targetPath: "python_bundle");
-    debugPrint("pythonLibPath: $pythonLibPath");
+    spDebug("pythonLibPath: $pythonLibPath");
 
     var programDirPath = p.dirname(appPath);
 
@@ -74,22 +74,22 @@ class SeriousPythonAndroid extends SeriousPythonPlatform {
     if (await File(sitePackagesZipPath).exists()) {
       var sitePackagesPath = await extractFileZip(sitePackagesZipPath,
           targetPath: "python_site_packages");
-      debugPrint("sitePackagesPath: $sitePackagesPath");
+      spDebug("sitePackagesPath: $sitePackagesPath");
       moduleSearchPaths.add(sitePackagesPath);
     }
 
-    setenv("PYTHONINSPECT", "1");
-    setenv("PYTHONDONTWRITEBYTECODE", "1");
-    setenv("PYTHONNOUSERSITE", "1");
-    setenv("PYTHONUNBUFFERED", "1");
-    setenv("LC_CTYPE", "UTF-8");
-    setenv("PYTHONHOME", pythonLibPath);
-    setenv("PYTHONPATH", moduleSearchPaths.join(":"));
+    await setenv("PYTHONINSPECT", "1");
+    await setenv("PYTHONDONTWRITEBYTECODE", "1");
+    await setenv("PYTHONNOUSERSITE", "1");
+    await setenv("PYTHONUNBUFFERED", "1");
+    await setenv("LC_CTYPE", "UTF-8");
+    await setenv("PYTHONHOME", pythonLibPath);
+    await setenv("PYTHONPATH", moduleSearchPaths.join(":"));
 
     // set environment variables
     if (environmentVariables != null) {
       for (var v in environmentVariables.entries) {
-        setenv(v.key, v.value);
+        await setenv(v.key, v.value);
       }
     }
 

src/serious_python_android/lib/src/cpython.dart

@@ -3,14 +3,46 @@ import 'dart:ffi';
 import 'dart:isolate';
 
 import 'package:ffi/ffi.dart';
-import 'package:flutter/foundation.dart';
 import 'package:path/path.dart' as p;
 
 import 'gen.dart';
+import 'log.dart';
 
 export 'gen.dart';
 
 CPython? _cpython;
+String? _logcatForwardingError;
+const _logcatInitScript = r'''
+import sys, logging
+
+# Make this init idempotent across Dart isolate restarts.
+if not getattr(sys, "__serious_python_logcat_configured__", False):
+    sys.__serious_python_logcat_configured__ = True
+
+    from ctypes import cdll
+    liblog = cdll.LoadLibrary("liblog.so")
+    ANDROID_LOG_INFO = 4
+
+    def _log_to_logcat(msg, level=ANDROID_LOG_INFO):
+        if not msg:
+            return
+        if isinstance(msg, bytes):
+            msg = msg.decode("utf-8", errors="replace")
+        liblog.__android_log_write(level, b"serious_python", msg.encode("utf-8"))
+
+    class _LogcatWriter:
+        def write(self, msg):
+            _log_to_logcat(msg.strip())
+        def flush(self):
+            pass
+
+    sys.stdout = sys.stderr = _LogcatWriter()
+    handler = logging.StreamHandler(sys.stderr)
+    handler.setFormatter(logging.Formatter("%(levelname)s %(message)s"))
+    root = logging.getLogger()
+    root.handlers[:] = [handler]
+    root.setLevel(logging.DEBUG)
+''';
 
 CPython getCPython(String dynamicLibPath) {
   return _cpython ??= _cpython = CPython(DynamicLibrary.open(dynamicLibPath));
@@ -46,21 +78,35 @@ Future<String> runPythonProgramInIsolate(List<Object> arguments) async {
   var programDirPath = p.dirname(pythonProgramPath);
   var programModuleName = p.basenameWithoutExtension(pythonProgramPath);
 
-  debugPrint("dynamicLibPath: $dynamicLibPath");
-  debugPrint("programDirPath: $programDirPath");
-  debugPrint("programModuleName: $programModuleName");
+  spDebug("dynamicLibPath: $dynamicLibPath");
+  spDebug("programDirPath: $programDirPath");
+  spDebug("programModuleName: $programModuleName");
 
   final cpython = getCPython(dynamicLibPath);
+  spDebug("CPython loaded");
+  if (cpython.Py_IsInitialized() != 0) {
+    spDebug("Python already initialized, skipping execution.");
+    sendPort.send("");
+    return "";
+  }
+
   cpython.Py_Initialize();
-  debugPrint("after Py_Initialize()");
+  spDebug("after Py_Initialize()");
 
   var result = "";
 
+  final logcatSetupError = _setupLogcatForwarding(cpython);
+  if (logcatSetupError != null) {
+    cpython.Py_Finalize();
+    sendPort.send(logcatSetupError);
+    return logcatSetupError;
+  }
+
   if (script != "") {
     // run script
     final scriptPtr = script.toNativeUtf8();
     int sr = cpython.PyRun_SimpleString(scriptPtr.cast<Char>());
-    debugPrint("PyRun_SimpleString for script result: $sr");
+    spDebug("PyRun_SimpleString for script result: $sr");
     malloc.free(scriptPtr);
     if (sr != 0) {
       result = getPythonError(cpython);
@@ -76,7 +122,7 @@ Future<String> runPythonProgramInIsolate(List<Object> arguments) async {
   }
 
   cpython.Py_Finalize();
-  debugPrint("after Py_Finalize()");
+  spDebug("after Py_Finalize()");
 
   sendPort.send(result);
 
@@ -94,7 +140,7 @@ String getPythonError(CPython cpython) {
   cpython.Py_DecRef(tracebackModuleNamePtr.cast());
 
   if (tracebackModulePtr != nullptr) {
-    //debugPrint("Traceback module loaded");
+    //spDebug("Traceback module loaded");
 
     final formatFuncName = "format_exception".toNativeUtf8();
     final pFormatFunc = cpython.PyObject_GetAttrString(
@@ -127,3 +173,20 @@ String getPythonError(CPython cpython) {
     return "Error loading traceback module.";
   }
 }
+
+String? _setupLogcatForwarding(CPython cpython) {
+  if (_logcatForwardingError != null) {
+    return _logcatForwardingError;
+  }
+
+  final setupPtr = _logcatInitScript.toNativeUtf8();
+  final result = cpython.PyRun_SimpleString(setupPtr.cast<Char>());
+  malloc.free(setupPtr);
+
+  if (result != 0) {
+    _logcatForwardingError = getPythonError(cpython);
+    return _logcatForwardingError;
+  }
+
+  return null;
+}

src/serious_python_android/lib/src/log.dart

@@ -0,0 +1,10 @@
+import 'package:flutter/foundation.dart';
+
+void spDebug(String message) {
+  if (message.startsWith('[serious_python]')) {
+    debugPrint(message);
+  } else {
+    debugPrint('[serious_python] $message');
+  }
+}
+

src/serious_python_android/pubspec.yaml

@@ -2,7 +2,7 @@ name: serious_python_android
 description: Android implementation of the serious_python plugin
 homepage: https://flet.dev
 repository: https://github.com/flet-dev/serious-python
-version: 0.9.6
+version: 0.9.7
 
 environment:
   sdk: ">=3.0.0 <4.0.0"

src/serious_python_darwin/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.9.7
+
+* Fix app restart on Android 10.
+* Redirect Python output to logcat.
+
 ## 0.9.6
 
 * Make zipDirectory call asynchronous.

src/serious_python_darwin/darwin/serious_python_darwin.podspec

@@ -4,7 +4,7 @@
 #
 Pod::Spec.new do |s|
   s.name             = 'serious_python_darwin'
-  s.version          = '0.9.6'
+  s.version          = '0.9.7'
   s.summary          = 'A cross-platform plugin for adding embedded Python runtime to your Flutter apps.'
   s.description      = <<-DESC
   A cross-platform plugin for adding embedded Python runtime to your Flutter apps.

src/serious_python_darwin/pubspec.yaml

@@ -2,7 +2,7 @@ name: serious_python_darwin
 description: iOS and macOS implementations of the serious_python plugin
 homepage: https://flet.dev
 repository: https://github.com/flet-dev/serious-python
-version: 0.9.6
+version: 0.9.7
 
 environment:
   sdk: ">=3.0.0 <4.0.0"

src/serious_python_linux/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.9.7
+
+* Fix app restart on Android 10.
+* Redirect Python output to logcat.
+
 ## 0.9.6
 
 * Make zipDirectory call asynchronous.

src/serious_python_linux/pubspec.yaml

@@ -2,7 +2,7 @@ name: serious_python_linux
 description: Linux implementations of the serious_python plugin
 homepage: https://flet.dev
 repository: https://github.com/flet-dev/serious-python
-version: 0.9.6
+version: 0.9.7
 
 environment:
   sdk: '>=3.1.3 <4.0.0'

src/serious_python_platform_interface/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.9.7
+
+* Fix app restart on Android 10.
+* Redirect Python output to logcat.
+
 ## 0.9.6
 
 * Make zipDirectory call asynchronous.

src/serious_python_platform_interface/lib/src/utils.dart

@@ -15,6 +15,12 @@ Future<String> extractAssetOrFile(String path,
       Directory(p.join(supportDir.path, "flet", targetPath ?? p.dirname(path)));
 
   String assetHash = "";
+  // read asset hash from asset
+  try {
+    assetHash = (await rootBundle.loadString("$path.hash")).trim();
+    // ignore: empty_catches
+  } catch (e) {}
+
   String destHash = "";
   var hashFile = File(p.join(destDir.path, ".hash"));
 
@@ -25,11 +31,6 @@ Future<String> extractAssetOrFile(String path,
       await destDir.delete(recursive: true);
     } else {
       if (checkHash) {
-        // read asset hash from asset
-        try {
-          assetHash = (await rootBundle.loadString("$path.hash")).trim();
-          // ignore: empty_catches
-        } catch (e) {}
         if (await hashFile.exists()) {
           destHash = (await hashFile.readAsString()).trim();
         }
@@ -72,6 +73,7 @@ Future<String> extractAssetOrFile(String path,
   debugPrint("Finished unpacking application archive in ${stopwatch.elapsed}");
 
   if (checkHash) {
+    debugPrint("Writing hash file: ${hashFile.path}, hash: $assetHash");
     await hashFile.writeAsString(assetHash);
   }
 

src/serious_python_platform_interface/pubspec.yaml

@@ -2,7 +2,7 @@ name: serious_python_platform_interface
 description: A common platform interface for the serious_python plugin.
 homepage: https://flet.dev
 repository: https://github.com/flet-dev/serious-python
-version: 0.9.6
+version: 0.9.7
 
 environment:
   sdk: ">=3.0.0 <4.0.0"

src/serious_python_windows/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.9.7
+
+* Fix app restart on Android 10.
+* Redirect Python output to logcat.
+
 ## 0.9.6
 
 * Make zipDirectory call asynchronous.

src/serious_python_windows/pubspec.yaml

@@ -2,7 +2,7 @@ name: serious_python_windows
 description: Windows implementations of the serious_python plugin
 homepage: https://flet.dev
 repository: https://github.com/flet-dev/serious-python
-version: 0.9.6
+version: 0.9.7
 
 environment:
   sdk: '>=3.1.3 <4.0.0'