cas: add CAS hal

Add CAS hal definitions and default service implementation.

bug: 22804304

Change-Id: I0a89608fe75c5f3c5e6888f9b771305742760707
diff --git a/cas/1.0/default/FactoryLoader.h b/cas/1.0/default/FactoryLoader.h
new file mode 100644
index 0000000..18c2186
--- /dev/null
+++ b/cas/1.0/default/FactoryLoader.h
@@ -0,0 +1,229 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_CAS_V1_0_FACTORY_LOADER_H_
+#define ANDROID_HARDWARE_CAS_V1_0_FACTORY_LOADER_H_
+
+#include <dirent.h>
+#include <dlfcn.h>
+#include "SharedLibrary.h"
+#include <utils/KeyedVector.h>
+#include <utils/Mutex.h>
+#include <media/cas/CasAPI.h>
+
+using namespace std;
+
+namespace android {
+namespace hardware {
+namespace cas {
+namespace V1_0 {
+namespace implementation {
+
+template <class T>
+class FactoryLoader {
+public:
+    FactoryLoader(const char *name) :
+        mFactory(NULL), mCreateFactoryFuncName(name) {}
+
+    virtual ~FactoryLoader() { closeFactory(); }
+
+    bool findFactoryForScheme(
+            int32_t CA_system_id,
+            sp<SharedLibrary> *library = NULL,
+            T** factory = NULL);
+
+    bool enumeratePlugins(vector<HidlCasPluginDescriptor>* results);
+
+private:
+    typedef T*(*CreateFactoryFunc)();
+
+    Mutex mMapLock;
+    T* mFactory;
+    const char *mCreateFactoryFuncName;
+    sp<SharedLibrary> mLibrary;
+    KeyedVector<int32_t, String8> mCASystemIdToLibraryPathMap;
+    KeyedVector<String8, wp<SharedLibrary> > mLibraryPathToOpenLibraryMap;
+
+    bool loadFactoryForSchemeFromPath(
+            const String8 &path,
+            int32_t CA_system_id,
+            sp<SharedLibrary> *library,
+            T** factory);
+
+    bool queryPluginsFromPath(
+            const String8 &path,
+            vector<HidlCasPluginDescriptor>* results);
+
+    bool openFactory(const String8 &path);
+    void closeFactory();
+};
+
+template <class T>
+bool FactoryLoader<T>::findFactoryForScheme(
+        int32_t CA_system_id, sp<SharedLibrary> *library, T** factory) {
+    if (library != NULL) {
+        library->clear();
+    }
+    if (factory != NULL) {
+        *factory = NULL;
+    }
+
+    Mutex::Autolock autoLock(mMapLock);
+
+    // first check cache
+    ssize_t index = mCASystemIdToLibraryPathMap.indexOfKey(CA_system_id);
+    if (index >= 0) {
+        return loadFactoryForSchemeFromPath(
+                mCASystemIdToLibraryPathMap[index],
+                CA_system_id, library, factory);
+    }
+
+    // no luck, have to search
+    String8 dirPath("/vendor/lib/mediacas");
+    DIR* pDir = opendir(dirPath.string());
+
+    if (pDir == NULL) {
+        ALOGE("Failed to open plugin directory %s", dirPath.string());
+        return false;
+    }
+
+    struct dirent* pEntry;
+    while ((pEntry = readdir(pDir))) {
+        String8 pluginPath = dirPath + "/" + pEntry->d_name;
+        if (pluginPath.getPathExtension() == ".so") {
+            if (loadFactoryForSchemeFromPath(
+                    pluginPath, CA_system_id, library, factory)) {
+                mCASystemIdToLibraryPathMap.add(CA_system_id, pluginPath);
+                closedir(pDir);
+
+                return true;
+            }
+        }
+    }
+
+    closedir(pDir);
+
+    ALOGE("Failed to find plugin");
+    return false;
+}
+
+template <class T>
+bool FactoryLoader<T>::enumeratePlugins(
+        vector<HidlCasPluginDescriptor>* results) {
+    ALOGI("enumeratePlugins");
+
+    results->clear();
+
+    String8 dirPath("/vendor/lib/mediacas");
+    DIR* pDir = opendir(dirPath.string());
+
+    if (pDir == NULL) {
+        ALOGE("Failed to open plugin directory %s", dirPath.string());
+        return false;
+    }
+
+    Mutex::Autolock autoLock(mMapLock);
+
+    struct dirent* pEntry;
+    while ((pEntry = readdir(pDir))) {
+        String8 pluginPath = dirPath + "/" + pEntry->d_name;
+        if (pluginPath.getPathExtension() == ".so") {
+            queryPluginsFromPath(pluginPath, results);
+        }
+    }
+    return true;
+}
+
+template <class T>
+bool FactoryLoader<T>::loadFactoryForSchemeFromPath(
+        const String8 &path, int32_t CA_system_id,
+        sp<SharedLibrary> *library, T** factory) {
+    closeFactory();
+
+    if (!openFactory(path) || !mFactory->isSystemIdSupported(CA_system_id)) {
+        closeFactory();
+        return false;
+    }
+
+    if (library != NULL) {
+        *library = mLibrary;
+    }
+    if (factory != NULL) {
+        *factory = mFactory;
+    }
+    return true;
+}
+
+template <class T>
+bool FactoryLoader<T>::queryPluginsFromPath(
+        const String8 &path, vector<HidlCasPluginDescriptor>* results) {
+    closeFactory();
+
+    vector<CasPluginDescriptor> descriptors;
+    if (!openFactory(path) || mFactory->queryPlugins(&descriptors) != OK) {
+        closeFactory();
+        return false;
+    }
+
+    for (auto it = descriptors.begin(); it != descriptors.end(); it++) {
+        results->push_back( HidlCasPluginDescriptor {
+                .caSystemId = it->CA_system_id,
+                .name = it->name.c_str()});
+    }
+    return true;
+}
+
+template <class T>
+bool FactoryLoader<T>::openFactory(const String8 &path) {
+    // get strong pointer to open shared library
+    ssize_t index = mLibraryPathToOpenLibraryMap.indexOfKey(path);
+    if (index >= 0) {
+        mLibrary = mLibraryPathToOpenLibraryMap[index].promote();
+    } else {
+        index = mLibraryPathToOpenLibraryMap.add(path, NULL);
+    }
+
+    if (!mLibrary.get()) {
+        mLibrary = new SharedLibrary(path);
+        if (!*mLibrary) {
+            return false;
+        }
+
+        mLibraryPathToOpenLibraryMap.replaceValueAt(index, mLibrary);
+    }
+
+    CreateFactoryFunc createFactory =
+        (CreateFactoryFunc)mLibrary->lookup(mCreateFactoryFuncName);
+    if (createFactory == NULL || (mFactory = createFactory()) == NULL) {
+        return false;
+    }
+    return true;
+}
+
+template <class T>
+void FactoryLoader<T>::closeFactory() {
+    delete mFactory;
+    mFactory = NULL;
+    mLibrary.clear();
+}
+
+} // namespace implementation
+} // namespace V1_0
+} // namespace cas
+} // namespace hardware
+} // namespace android
+
+#endif // ANDROID_HARDWARE_CAS_V1_0_FACTORY_LOADER_H_