add feature to clear ml downloads

packages/flutter_mozilla_components/android/src/main/assets/extensions/ml_engine/api/ml.js

@@ -6,8 +6,11 @@
 
 const {
     createEngine,
+    EngineProcess,
     FEATURES,
 } = ChromeUtils.importESModule("chrome://global/content/ml/EngineProcess.sys.mjs");
+const { ModelHub } = ChromeUtils.importESModule("chrome://global/content/ml/ModelHub.sys.mjs");
+const { OPFS } = ChromeUtils.importESModule("chrome://global/content/ml/OPFS.sys.mjs");
 
 const ML_TASK_FEATURE_EXTRACTION = "feature-extraction";
 const ML_TASK_TEXT2TEXT = "text2text-generation";
@@ -154,7 +157,7 @@ async function createMlEngine(engineConfig, progressCallback) {
         numThreads,
     };
 
-        return await createEngine(initData, progressCallback);
+    return await createEngine(initData, progressCallback);
 }
 
 this.ml = class extends ExtensionAPI {
@@ -234,6 +237,16 @@ this.ml = class extends ExtensionAPI {
                         const generated = cutAtDuplicateWords((res[0]["generated_text"] || "").trim());
 
                         return generated;
+                    },
+                    async clearCache() {
+                        self.embeddingEngine = null;
+                        self.topicEngine = null;
+
+                        await EngineProcess.destroyMLEngine();
+                        await new ModelHub().purgeDatabase();
+                        await OPFS.remove("mlRuntimeFiles", { recursive: true });
+
+                        return true;
                     }
                 }
             }

packages/flutter_mozilla_components/android/src/main/assets/extensions/ml_engine/background.js

@@ -56,6 +56,12 @@ port.onMessage.addListener(async (message) => {
                 sendJsonResultForRequest(requestId)(result);
                 break;
             }
+            case "clearMlCache": {
+                const result = await browser.experiments.ml.clearCache();
+
+                sendJsonResultForRequest(requestId)(result);
+                break;
+            }
             default:
                 throw new Error(`Unsupported ML action: ${message["action"]}`);
         }

packages/flutter_mozilla_components/android/src/main/assets/extensions/ml_engine/schema.json

@@ -85,7 +85,14 @@
                         "description": "Array of document titles/content"
                     }
                 ]
+            },
+            {
+                "name": "clearCache",
+                "type": "function",
+                "description": "Clear downloaded ML models and runtime files",
+                "async": true,
+                "parameters": []
             }
         ]
     }
-]
+]

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/api/GeckoMlApiImpl.kt

@@ -131,4 +131,16 @@ class GeckoMlApiImpl(
         })
     }
 
-}
+    override fun clearMlCache(callback: (Result<Unit>) -> Unit) {
+        MLEngineFeature.scheduleRequest("clearMlCache", JSONObject(), object : ResultConsumer<JSONObject> {
+            override fun success(result: JSONObject) {
+                callback(Result.success(Unit))
+            }
+
+            override fun error(errorCode: String, errorMessage: String?, errorDetails: Any?) {
+                callback(Result.failure(Exception("$errorCode $errorMessage $errorDetails")))
+            }
+        })
+    }
+
+}

packages/flutter_mozilla_components/android/src/main/kotlin/eu/weblibre/flutter_mozilla_components/pigeons/Gecko.g.kt

@@ -8315,6 +8315,7 @@ interface GeckoPrefApi {
 interface GeckoMlApi {
   fun predictDocumentTopic(documents: List<String>, callback: (Result<String>) -> Unit)
   fun generateDocumentEmbeddings(documents: List<String>, callback: (Result<List<Any?>>) -> Unit)
+  fun clearMlCache(callback: (Result<Unit>) -> Unit)
 
   companion object {
     /** The codec used by GeckoMlApi. */
@@ -8365,6 +8366,23 @@ interface GeckoMlApi {
           channel.setMessageHandler(null)
         }
       }
+      run {
+        val channel = BasicMessageChannel<Any?>(binaryMessenger, "dev.flutter.pigeon.flutter_mozilla_components.GeckoMlApi.clearMlCache$separatedMessageChannelSuffix", codec)
+        if (api != null) {
+          channel.setMessageHandler { _, reply ->
+            api.clearMlCache{ result: Result<Unit> ->
+              val error = result.exceptionOrNull()
+              if (error != null) {
+                reply.reply(GeckoPigeonUtils.wrapError(error))
+              } else {
+                reply.reply(GeckoPigeonUtils.wrapResult(null))
+              }
+            }
+          }
+        } else {
+          channel.setMessageHandler(null)
+        }
+      }
     }
   }
 }