Add media.log service based on NBLog

Change-Id: Ie45093df6ac9a739d05c8d408fab52a9a8a27e7f
diff --git a/services/medialog/Android.mk b/services/medialog/Android.mk
new file mode 100644
index 0000000..559b1ed
--- /dev/null
+++ b/services/medialog/Android.mk
@@ -0,0 +1,11 @@
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := MediaLogService.cpp
+
+LOCAL_SHARED_LIBRARIES := libmedia libbinder libutils libnbaio
+
+LOCAL_MODULE:= libmedialogservice
+
+include $(BUILD_SHARED_LIBRARY)
diff --git a/services/medialog/MediaLogService.cpp b/services/medialog/MediaLogService.cpp
new file mode 100644
index 0000000..2332b3e
--- /dev/null
+++ b/services/medialog/MediaLogService.cpp
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+#define LOG_TAG "MediaLog"
+//#define LOG_NDEBUG 0
+
+#include <sys/mman.h>
+#include <utils/Log.h>
+#include <media/nbaio/NBLog.h>
+#include <private/android_filesystem_config.h>
+#include "MediaLogService.h"
+
+namespace android {
+
+void MediaLogService::registerWriter(const sp<IMemory>& shared, size_t size, const char *name)
+{
+    if (IPCThreadState::self()->getCallingUid() != AID_MEDIA || shared == 0 ||
+            size < kMinSize || size > kMaxSize || name == NULL ||
+            shared->size() < NBLog::Timeline::sharedSize(size)) {
+        return;
+    }
+    sp<NBLog::Reader> reader(new NBLog::Reader(size, shared));
+    NamedReader namedReader(reader, name);
+    Mutex::Autolock _l(mLock);
+    mNamedReaders.add(namedReader);
+}
+
+void MediaLogService::unregisterWriter(const sp<IMemory>& shared)
+{
+    if (IPCThreadState::self()->getCallingUid() != AID_MEDIA || shared == 0) {
+        return;
+    }
+    Mutex::Autolock _l(mLock);
+    for (size_t i = 0; i < mNamedReaders.size(); ) {
+        if (mNamedReaders[i].reader()->isIMemory(shared)) {
+            mNamedReaders.removeAt(i);
+        } else {
+            i++;
+        }
+    }
+}
+
+status_t MediaLogService::dump(int fd, const Vector<String16>& args)
+{
+    Vector<NamedReader> namedReaders;
+    {
+        Mutex::Autolock _l(mLock);
+        namedReaders = mNamedReaders;
+    }
+    for (size_t i = 0; i < namedReaders.size(); i++) {
+        const NamedReader& namedReader = namedReaders[i];
+        if (fd >= 0) {
+            fdprintf(fd, "\n%s:\n", namedReader.name());
+        } else {
+            ALOGI("%s:", namedReader.name());
+        }
+        namedReader.reader()->dump(fd, 0 /*indent*/);
+    }
+    return NO_ERROR;
+}
+
+status_t MediaLogService::onTransact(uint32_t code, const Parcel& data, Parcel* reply,
+        uint32_t flags)
+{
+    return BnMediaLogService::onTransact(code, data, reply, flags);
+}
+
+}   // namespace android
diff --git a/services/medialog/MediaLogService.h b/services/medialog/MediaLogService.h
new file mode 100644
index 0000000..2d89a41
--- /dev/null
+++ b/services/medialog/MediaLogService.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2013 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_MEDIA_LOG_SERVICE_H
+#define ANDROID_MEDIA_LOG_SERVICE_H
+
+#include <binder/BinderService.h>
+#include <media/IMediaLogService.h>
+#include <media/nbaio/NBLog.h>
+
+namespace android {
+
+class MediaLogService : public BinderService<MediaLogService>, public BnMediaLogService
+{
+    friend class BinderService<MediaLogService>;    // for MediaLogService()
+public:
+    MediaLogService() : BnMediaLogService() { }
+    virtual ~MediaLogService() { }
+    virtual void onFirstRef() { }
+
+    static const char*  getServiceName() { return "media.log"; }
+
+    static const size_t kMinSize = 0x100;
+    static const size_t kMaxSize = 0x10000;
+    virtual void        registerWriter(const sp<IMemory>& shared, size_t size, const char *name);
+    virtual void        unregisterWriter(const sp<IMemory>& shared);
+
+    virtual status_t    dump(int fd, const Vector<String16>& args);
+    virtual status_t    onTransact(uint32_t code, const Parcel& data, Parcel* reply,
+                                uint32_t flags);
+
+private:
+    Mutex               mLock;
+    class NamedReader {
+    public:
+        NamedReader() : mReader(0) { mName[0] = '\0'; } // for Vector
+        NamedReader(const sp<NBLog::Reader>& reader, const char *name) : mReader(reader)
+            { strlcpy(mName, name, sizeof(mName)); }
+        ~NamedReader() { }
+        const sp<NBLog::Reader>&  reader() const { return mReader; }
+        const char*               name() const { return mName; }
+    private:
+        sp<NBLog::Reader>   mReader;
+        static const size_t kMaxName = 32;
+        char                mName[kMaxName];
+    };
+    Vector<NamedReader> mNamedReaders;
+};
+
+}   // namespace android
+
+#endif  // ANDROID_MEDIA_LOG_SERVICE_H