Package com.tencent.mmkv

Class MMKV

  • All Implemented Interfaces:
    android.content.SharedPreferences, android.content.SharedPreferences.Editor
    public class MMKV
extends java.lang.Object
implements android.content.SharedPreferences, android.content.SharedPreferences.Editor
    An highly efficient, reliable, multi-process key-value storage framework. THE PERFECT drop-in replacement for SharedPreferences and MultiProcessSharedPreferences.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static interface  MMKV.LibLoader
      The interface for providing a 3rd library loader (the ReLinker https://github.com/KeepSafe/ReLinker, etc).

      • Nested classes/interfaces inherited from interface android.content.SharedPreferences

        android.content.SharedPreferences.Editor, android.content.SharedPreferences.OnSharedPreferenceChangeListener

    • Method Summary

      Modifier and Type Method Description
      long actualSize()
      Get the actual used size of the MMKV instance.
      java.lang.String[] allKeys()  
      java.lang.String[] allNonExpireKeys()  
      void apply()
      Deprecated.
      This method is only for compatibility purpose.
      int ashmemFD()  
      int ashmemMetaFD()  
      void async()
      Save all mmap memory to file asynchronously.
      static MMKV backedUpMMKVWithID​(java.lang.String mmapID, int mode, java.lang.String cryptKey, java.lang.String rootPath)
      Get an backed-up MMKV instance with customize settings all in one.
      static long backupAllToDirectory​(java.lang.String dstDir)
      backup all MMKV instance to dstDir
      static boolean backupOneToDirectory​(java.lang.String mmapID, java.lang.String dstDir, java.lang.String rootPath)
      backup one MMKV instance to dstDir
      void checkContentChangedByOuterProcess()
      Check inter-process content change manually.
      void checkReSetCryptKey​(java.lang.String cryptKey)
      Just reset the encryption key (will not encrypt or decrypt anything).
      android.content.SharedPreferences.Editor clear()
      clearAll()
      void clearAll()
      Clear all the key-values inside the MMKV instance.
      void clearMemoryCache()
      Clear memory cache of the MMKV instance.
      void close()
      Call this method if the MMKV instance is no longer needed in the near future.
      boolean commit()
      Deprecated.
      This method is only for compatibility purpose.
      boolean contains​(java.lang.String key)  
      boolean containsKey​(java.lang.String key)
      Check whether or not MMKV contains the key.
      long count()  
      long countNonExpiredKeys()  
      static NativeBuffer createNativeBuffer​(int size)
      Create an native buffer, whose underlying memory can be directly transferred to another JNI method.
      java.lang.String cryptKey()  
      boolean decodeBool​(java.lang.String key)  
      boolean decodeBool​(java.lang.String key, boolean defaultValue)  
      byte[] decodeBytes​(java.lang.String key)  
      byte[] decodeBytes​(java.lang.String key, byte[] defaultValue)  
      double decodeDouble​(java.lang.String key)  
      double decodeDouble​(java.lang.String key, double defaultValue)  
      float decodeFloat​(java.lang.String key)  
      float decodeFloat​(java.lang.String key, float defaultValue)  
      int decodeInt​(java.lang.String key)  
      int decodeInt​(java.lang.String key, int defaultValue)  
      long decodeLong​(java.lang.String key)  
      long decodeLong​(java.lang.String key, long defaultValue)  
      <T extends android.os.Parcelable>
      T      		 decodeParcelable​(java.lang.String key, java.lang.Class<T> tClass)  
      <T extends android.os.Parcelable>
      T      		 decodeParcelable​(java.lang.String key, java.lang.Class<T> tClass, T defaultValue)  
      java.lang.String decodeString​(java.lang.String key)  
      java.lang.String decodeString​(java.lang.String key, java.lang.String defaultValue)  
      java.util.Set<java.lang.String> decodeStringSet​(java.lang.String key)  
      java.util.Set<java.lang.String> decodeStringSet​(java.lang.String key, java.util.Set<java.lang.String> defaultValue)  
      java.util.Set<java.lang.String> decodeStringSet​(java.lang.String key, java.util.Set<java.lang.String> defaultValue, java.lang.Class<? extends java.util.Set> cls)  
      static MMKV defaultMMKV()
      Create the default MMKV instance in single-process mode.
      static MMKV defaultMMKV​(int mode, java.lang.String cryptKey)
      Create the default MMKV instance in customize process mode, with an encryption key.
      static void destroyNativeBuffer​(NativeBuffer buffer)
      Destroy the native buffer.
      boolean disableAutoKeyExpire()
      Disable auto key expiration.
      static void disableProcessModeChecker()
      Manually disable the process mode checker.
      android.content.SharedPreferences.Editor edit()  
      boolean enableAutoKeyExpire​(int expireDurationInSecond)
      Enable auto key expiration.
      static void enableProcessModeChecker()
      Manually enable the process mode checker.
      boolean encode​(java.lang.String key, boolean value)  
      boolean encode​(java.lang.String key, boolean value, int expireDurationInSecond)
      Set value with customize expiration in sections.
      boolean encode​(java.lang.String key, byte[] value)  
      boolean encode​(java.lang.String key, byte[] value, int expireDurationInSecond)
      Set value with customize expiration in sections.
      boolean encode​(java.lang.String key, double value)  
      boolean encode​(java.lang.String key, double value, int expireDurationInSecond)
      Set value with customize expiration in sections.
      boolean encode​(java.lang.String key, float value)  
      boolean encode​(java.lang.String key, float value, int expireDurationInSecond)
      Set value with customize expiration in sections.
      boolean encode​(java.lang.String key, int value)  
      boolean encode​(java.lang.String key, int value, int expireDurationInSecond)
      Set value with customize expiration in sections.
      boolean encode​(java.lang.String key, long value)  
      boolean encode​(java.lang.String key, long value, int expireDurationInSecond)
      Set value with customize expiration in sections.
      boolean encode​(java.lang.String key, android.os.Parcelable value)  
      boolean encode​(java.lang.String key, android.os.Parcelable value, int expireDurationInSecond)
      Set value with customize expiration in sections.
      boolean encode​(java.lang.String key, java.lang.String value)  
      boolean encode​(java.lang.String key, java.lang.String value, int expireDurationInSecond)
      Set value with customize expiration in sections.
      boolean encode​(java.lang.String key, java.util.Set<java.lang.String> value)  
      boolean encode​(java.lang.String key, java.util.Set<java.lang.String> value, int expireDurationInSecond)
      Set value with customize expiration in sections.
      java.util.Map<java.lang.String,​?> getAll()
      Intentionally Not Supported.
      boolean getBoolean​(java.lang.String key, boolean defValue)  
      byte[] getBytes​(java.lang.String key, byte[] defValue)  
      float getFloat​(java.lang.String key, float defValue)  
      int getInt​(java.lang.String key, int defValue)  
      long getLong​(java.lang.String key, long defValue)  
      static java.lang.String getRootDir()  
      java.lang.String getString​(java.lang.String key, java.lang.String defValue)  
      java.util.Set<java.lang.String> getStringSet​(java.lang.String key, java.util.Set<java.lang.String> defValues)  
      int getValueActualSize​(java.lang.String key)
      Get the actual size of the key's value.
      int getValueSize​(java.lang.String key)
      Get the actual size consumption of the key's value.
      int importFromSharedPreferences​(android.content.SharedPreferences preferences)
      Atomically migrate all key-values from an existent SharedPreferences to the MMKV instance.
      static java.lang.String initialize​(android.content.Context context)
      Initialize MMKV with default configuration.
      static java.lang.String initialize​(android.content.Context context, MMKV.LibLoader loader)
      Initialize MMKV with a 3rd library loader.
      static java.lang.String initialize​(android.content.Context context, MMKV.LibLoader loader, MMKVLogLevel logLevel)
      Initialize MMKV with a 3rd library loader, and customize log level.
      static java.lang.String initialize​(android.content.Context context, MMKVLogLevel logLevel)
      Initialize MMKV with customize log level.
      static java.lang.String initialize​(android.content.Context context, java.lang.String rootDir)
      Initialize MMKV with customize root folder.
      static java.lang.String initialize​(android.content.Context context, java.lang.String rootDir, MMKV.LibLoader loader)
      Initialize MMKV with customize root folder, and a 3rd library loader.
      static java.lang.String initialize​(android.content.Context context, java.lang.String rootDir, MMKV.LibLoader loader, MMKVLogLevel logLevel)
      Initialize MMKV with customize settings.
      static java.lang.String initialize​(android.content.Context context, java.lang.String rootDir, MMKV.LibLoader loader, MMKVLogLevel logLevel, MMKVHandler handler)  
      static java.lang.String initialize​(android.content.Context context, java.lang.String rootDir, MMKVLogLevel logLevel)
      Initialize MMKV with customize root folder, and log level.
      static java.lang.String initialize​(java.lang.String rootDir)
      Deprecated.
      This method is deprecated due to failing to automatically disable checkProcessMode() without Context.
      static java.lang.String initialize​(java.lang.String rootDir, MMKV.LibLoader loader)
      Deprecated.
      This method is deprecated due to failing to automatically disable checkProcessMode() without Context.
      static java.lang.String initialize​(java.lang.String rootDir, MMKV.LibLoader loader, MMKVLogLevel logLevel)
      Deprecated.
      This method is deprecated due to failing to automatically disable checkProcessMode() without Context.
      static java.lang.String initialize​(java.lang.String rootDir, MMKVLogLevel logLevel)
      Deprecated.
      This method is deprecated due to failing to automatically disable checkProcessMode() without Context.
      static boolean isFileValid​(java.lang.String mmapID)
      Check whether the MMKV file is valid or not.
      static boolean isFileValid​(java.lang.String mmapID, java.lang.String rootPath)
      Check whether the MMKV file is valid or not on customize folder.
      void lock()
      Exclusively inter-process lock the MMKV instance.
      java.lang.String mmapID()  
      static MMKV mmkvWithAshmemFD​(java.lang.String mmapID, int fd, int metaFD, java.lang.String cryptKey)
      Get an ashmem MMKV instance that has been initiated by another process.
      static MMKV mmkvWithAshmemID​(android.content.Context context, java.lang.String mmapID, int size, int mode, java.lang.String cryptKey)
      Create an MMKV instance base on Anonymous Shared Memory, aka not synced to any disk files.
      static MMKV mmkvWithID​(java.lang.String mmapID)
      Create an MMKV instance with an unique ID (in single-process mode).
      static MMKV mmkvWithID​(java.lang.String mmapID, int mode)
      Create an MMKV instance in single-process or multi-process mode.
      static MMKV mmkvWithID​(java.lang.String mmapID, int mode, java.lang.String cryptKey)
      Create an MMKV instance in customize process mode, with an encryption key.
      static MMKV mmkvWithID​(java.lang.String mmapID, int mode, java.lang.String cryptKey, java.lang.String rootPath)
      Create an MMKV instance with customize settings all in one.
      static MMKV mmkvWithID​(java.lang.String mmapID, java.lang.String rootPath)
      Create an MMKV instance in customize folder.
      static void onExit()
      Notify MMKV that App is about to exit.
      static int pageSize()  
      android.content.SharedPreferences.Editor putBoolean​(java.lang.String key, boolean value)  
      android.content.SharedPreferences.Editor putBoolean​(java.lang.String key, boolean value, int expireDurationInSecond)  
      android.content.SharedPreferences.Editor putBytes​(java.lang.String key, byte[] bytes)  
      android.content.SharedPreferences.Editor putBytes​(java.lang.String key, byte[] bytes, int expireDurationInSecond)  
      android.content.SharedPreferences.Editor putFloat​(java.lang.String key, float value)  
      android.content.SharedPreferences.Editor putFloat​(java.lang.String key, float value, int expireDurationInSecond)  
      android.content.SharedPreferences.Editor putInt​(java.lang.String key, int value)  
      android.content.SharedPreferences.Editor putInt​(java.lang.String key, int value, int expireDurationInSecond)  
      android.content.SharedPreferences.Editor putLong​(java.lang.String key, long value)  
      android.content.SharedPreferences.Editor putLong​(java.lang.String key, long value, int expireDurationInSecond)  
      android.content.SharedPreferences.Editor putString​(java.lang.String key, java.lang.String value)  
      android.content.SharedPreferences.Editor putString​(java.lang.String key, java.lang.String value, int expireDurationInSecond)  
      android.content.SharedPreferences.Editor putStringSet​(java.lang.String key, java.util.Set<java.lang.String> values)  
      android.content.SharedPreferences.Editor putStringSet​(java.lang.String key, java.util.Set<java.lang.String> values, int expireDurationInSecond)  
      static void registerContentChangeNotify​(MMKVContentChangeNotification notify)
      Register for MMKV inter-process content change notification.
      static void registerHandler​(MMKVHandler handler)
      Deprecated.
      This method is deprecated.
      void registerOnSharedPreferenceChangeListener​(android.content.SharedPreferences.OnSharedPreferenceChangeListener listener)
      Intentionally Not Supported by MMKV.
      boolean reKey​(java.lang.String cryptKey)
      Transform plain text into encrypted text, or vice versa by passing a null encryption key.
      android.content.SharedPreferences.Editor remove​(java.lang.String key)  
      void removeValueForKey​(java.lang.String key)  
      void removeValuesForKeys​(java.lang.String[] arrKeys)
      Batch remove some keys from the MMKV instance.
      static long restoreAllFromDirectory​(java.lang.String srcDir)
      restore all MMKV instance from srcDir
      static boolean restoreOneMMKVFromDirectory​(java.lang.String mmapID, java.lang.String srcDir, java.lang.String rootPath)
      restore one MMKV instance from srcDir
      static void setLogLevel​(MMKVLogLevel level)
      Set the log level of MMKV.
      void sync()
      Save all mmap memory to file synchronously.
      long totalSize()
      Get the size of the underlying file.
      void trim()
      The totalSize() of an MMKV instance won't reduce after deleting key-values, call this method after lots of deleting if you care about disk usage.
      boolean tryLock()
      Try exclusively inter-process lock the MMKV instance.
      void unlock()
      Exclusively inter-process unlock the MMKV instance.
      static void unregisterContentChangeNotify()
      Unregister for MMKV inter-process content change notification.
      static void unregisterHandler()
      Unregister the handler for MMKV.
      void unregisterOnSharedPreferenceChangeListener​(android.content.SharedPreferences.OnSharedPreferenceChangeListener listener)
      Intentionally Not Supported by MMKV.
      static java.lang.String version()  
      int writeValueToNativeBuffer​(java.lang.String key, NativeBuffer buffer)
      Write the value of the key to the native buffer.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • SINGLE_PROCESS_MODE

        public static final int SINGLE_PROCESS_MODE
        Single-process mode. The default mode on an MMKV instance.
        See Also:
        Constant Field Values

      • MULTI_PROCESS_MODE

        public static final int MULTI_PROCESS_MODE
        Multi-process mode. To enable multi-process accessing of an MMKV instance, you must set this mode whenever you getting that instance.
        See Also:
        Constant Field Values

    • Method Detail

      • initialize

        public static java.lang.String initialize​(android.content.Context context)
        Initialize MMKV with default configuration. You must call one of the initialize() methods on App startup process before using MMKV.
        Parameters:
        context - The context of Android App, usually from Application.
        Returns:
        The root folder of MMKV, defaults to $(FilesDir)/mmkv.

      • initialize

        public static java.lang.String initialize​(android.content.Context context,
                                          MMKVLogLevel logLevel)
        Initialize MMKV with customize log level. You must call one of the initialize() methods on App startup process before using MMKV.
        Parameters:
        context - The context of Android App, usually from Application.
        logLevel - The log level of MMKV, defaults to MMKVLogLevel.LevelInfo.
        Returns:
        The root folder of MMKV, defaults to $(FilesDir)/mmkv.

      • initialize

        public static java.lang.String initialize​(android.content.Context context,
                                          MMKV.LibLoader loader)
        Initialize MMKV with a 3rd library loader. You must call one of the initialize() methods on App startup process before using MMKV.
        Parameters:
        context - The context of Android App, usually from Application.
        loader - The 3rd library loader (for example, the ReLinker .
        Returns:
        The root folder of MMKV, defaults to $(FilesDir)/mmkv.

      • initialize

        public static java.lang.String initialize​(android.content.Context context,
                                          MMKV.LibLoader loader,
                                          MMKVLogLevel logLevel)
        Initialize MMKV with a 3rd library loader, and customize log level. You must call one of the initialize() methods on App startup process before using MMKV.
        Parameters:
        context - The context of Android App, usually from Application.
        loader - The 3rd library loader (for example, the ReLinker .
        logLevel - The log level of MMKV, defaults to MMKVLogLevel.LevelInfo.
        Returns:
        The root folder of MMKV, defaults to $(FilesDir)/mmkv.

      • initialize

        public static java.lang.String initialize​(android.content.Context context,
                                          java.lang.String rootDir)
        Initialize MMKV with customize root folder. You must call one of the initialize() methods on App startup process before using MMKV.
        Parameters:
        context - The context of Android App, usually from Application.
        rootDir - The root folder of MMKV, defaults to $(FilesDir)/mmkv.
        Returns:
        The root folder of MMKV.

      • initialize

        public static java.lang.String initialize​(android.content.Context context,
                                          java.lang.String rootDir,
                                          MMKVLogLevel logLevel)
        Initialize MMKV with customize root folder, and log level. You must call one of the initialize() methods on App startup process before using MMKV.
        Parameters:
        context - The context of Android App, usually from Application.
        rootDir - The root folder of MMKV, defaults to $(FilesDir)/mmkv.
        logLevel - The log level of MMKV, defaults to MMKVLogLevel.LevelInfo.
        Returns:
        The root folder of MMKV.

      • initialize

        public static java.lang.String initialize​(android.content.Context context,
                                          java.lang.String rootDir,
                                          MMKV.LibLoader loader)
        Initialize MMKV with customize root folder, and a 3rd library loader. You must call one of the initialize() methods on App startup process before using MMKV.
        Parameters:
        context - The context of Android App, usually from Application.
        rootDir - The root folder of MMKV, defaults to $(FilesDir)/mmkv.
        loader - The 3rd library loader (for example, the ReLinker .
        Returns:
        The root folder of MMKV.

      • initialize

        public static java.lang.String initialize​(android.content.Context context,
                                          java.lang.String rootDir,
                                          MMKV.LibLoader loader,
                                          MMKVLogLevel logLevel)
        Initialize MMKV with customize settings. You must call one of the initialize() methods on App startup process before using MMKV.
        Parameters:
        context - The context of Android App, usually from Application.
        rootDir - The root folder of MMKV, defaults to $(FilesDir)/mmkv.
        loader - The 3rd library loader (for example, the ReLinker .
        logLevel - The log level of MMKV, defaults to MMKVLogLevel.LevelInfo.
        Returns:
        The root folder of MMKV.

      • initialize

        public static java.lang.String initialize​(android.content.Context context,
                                          java.lang.String rootDir,
                                          MMKV.LibLoader loader,
                                          MMKVLogLevel logLevel,
                                          MMKVHandler handler)

      • initialize

        @Deprecated
public static java.lang.String initialize​(java.lang.String rootDir)
        Deprecated.
        This method is deprecated due to failing to automatically disable checkProcessMode() without Context. Use the initialize(Context, String) method instead.

      • initialize

        @Deprecated
public static java.lang.String initialize​(java.lang.String rootDir,
                                          MMKVLogLevel logLevel)
        Deprecated.
        This method is deprecated due to failing to automatically disable checkProcessMode() without Context. Use the initialize(Context, String, MMKVLogLevel) method instead.

      • initialize

        @Deprecated
public static java.lang.String initialize​(java.lang.String rootDir,
                                          MMKV.LibLoader loader)
        Deprecated.
        This method is deprecated due to failing to automatically disable checkProcessMode() without Context. Use the initialize(Context, String, LibLoader) method instead.

      • getRootDir

        public static java.lang.String getRootDir()
        Returns:
        The root folder of MMKV, defaults to $(FilesDir)/mmkv.

      • onExit

        public static void onExit()
        Notify MMKV that App is about to exit. It's totally fine not calling it at all.

      • mmkvWithID

        public static MMKV mmkvWithID​(java.lang.String mmapID)
                       throws java.lang.RuntimeException
        Create an MMKV instance with an unique ID (in single-process mode).
        Parameters:
        mmapID - The unique ID of the MMKV instance.
        Throws:
        java.lang.RuntimeException - if there's an runtime error.

      • mmkvWithID

        public static MMKV mmkvWithID​(java.lang.String mmapID,
                              int mode)
                       throws java.lang.RuntimeException
        Create an MMKV instance in single-process or multi-process mode.
        Parameters:
        mmapID - The unique ID of the MMKV instance.
        mode - The process mode of the MMKV instance, defaults to SINGLE_PROCESS_MODE.
        Throws:
        java.lang.RuntimeException - if there's an runtime error.

      • mmkvWithID

        public static MMKV mmkvWithID​(java.lang.String mmapID,
                              int mode,
                              @Nullable
                              java.lang.String cryptKey)
                       throws java.lang.RuntimeException
        Create an MMKV instance in customize process mode, with an encryption key.
        Parameters:
        mmapID - The unique ID of the MMKV instance.
        mode - The process mode of the MMKV instance, defaults to SINGLE_PROCESS_MODE.
        cryptKey - The encryption key of the MMKV instance (no more than 16 bytes).
        Throws:
        java.lang.RuntimeException - if there's an runtime error.

      • mmkvWithID

        public static MMKV mmkvWithID​(java.lang.String mmapID,
                              java.lang.String rootPath)
                       throws java.lang.RuntimeException
        Create an MMKV instance in customize folder.
        Parameters:
        mmapID - The unique ID of the MMKV instance.
        rootPath - The folder of the MMKV instance, defaults to $(FilesDir)/mmkv.
        Throws:
        java.lang.RuntimeException - if there's an runtime error.

      • mmkvWithID

        public static MMKV mmkvWithID​(java.lang.String mmapID,
                              int mode,
                              @Nullable
                              java.lang.String cryptKey,
                              java.lang.String rootPath)
                       throws java.lang.RuntimeException
        Create an MMKV instance with customize settings all in one.
        Parameters:
        mmapID - The unique ID of the MMKV instance.
        mode - The process mode of the MMKV instance, defaults to SINGLE_PROCESS_MODE.
        cryptKey - The encryption key of the MMKV instance (no more than 16 bytes).
        rootPath - The folder of the MMKV instance, defaults to $(FilesDir)/mmkv.
        Throws:
        java.lang.RuntimeException - if there's an runtime error.

      • backedUpMMKVWithID

        public static MMKV backedUpMMKVWithID​(java.lang.String mmapID,
                                      int mode,
                                      @Nullable
                                      java.lang.String cryptKey,
                                      java.lang.String rootPath)
                               throws java.lang.RuntimeException
        Get an backed-up MMKV instance with customize settings all in one.
        Parameters:
        mmapID - The unique ID of the MMKV instance.
        mode - The process mode of the MMKV instance, defaults to SINGLE_PROCESS_MODE.
        cryptKey - The encryption key of the MMKV instance (no more than 16 bytes).
        rootPath - The backup folder of the MMKV instance.
        Throws:
        java.lang.RuntimeException - if there's an runtime error.

      • mmkvWithAshmemID

        public static MMKV mmkvWithAshmemID​(android.content.Context context,
                                    java.lang.String mmapID,
                                    int size,
                                    int mode,
                                    @Nullable
                                    java.lang.String cryptKey)
                             throws java.lang.RuntimeException
        Create an MMKV instance base on Anonymous Shared Memory, aka not synced to any disk files.
        Parameters:
        context - The context of Android App, usually from Application.
        mmapID - The unique ID of the MMKV instance.
        size - The maximum size of the underlying Anonymous Shared Memory. Anonymous Shared Memory on Android can't grow dynamically, must set an appropriate size on creation.
        mode - The process mode of the MMKV instance, defaults to SINGLE_PROCESS_MODE.
        cryptKey - The encryption key of the MMKV instance (no more than 16 bytes).
        Throws:
        java.lang.RuntimeException - if there's an runtime error.

      • defaultMMKV

        public static MMKV defaultMMKV()
                        throws java.lang.RuntimeException
        Create the default MMKV instance in single-process mode.
        Throws:
        java.lang.RuntimeException - if there's an runtime error.

      • defaultMMKV

        public static MMKV defaultMMKV​(int mode,
                               @Nullable
                               java.lang.String cryptKey)
                        throws java.lang.RuntimeException
        Create the default MMKV instance in customize process mode, with an encryption key.
        Parameters:
        mode - The process mode of the MMKV instance, defaults to SINGLE_PROCESS_MODE.
        cryptKey - The encryption key of the MMKV instance (no more than 16 bytes).
        Throws:
        java.lang.RuntimeException - if there's an runtime error.

      • enableProcessModeChecker

        public static void enableProcessModeChecker()
        Manually enable the process mode checker. By default, it's automatically enabled in DEBUG build, and disabled in RELEASE build. If it's enabled, MMKV will throw exceptions when an MMKV instance is created with mismatch process mode.

      • disableProcessModeChecker

        public static void disableProcessModeChecker()
        Manually disable the process mode checker. By default, it's automatically enabled in DEBUG build, and disabled in RELEASE build. If it's enabled, MMKV will throw exceptions when an MMKV instance is created with mismatch process mode.

      • cryptKey

        @Nullable
public java.lang.String cryptKey()
        Returns:
        The encryption key (no more than 16 bytes).

      • reKey

        public boolean reKey​(@Nullable
                     java.lang.String cryptKey)
        Transform plain text into encrypted text, or vice versa by passing a null encryption key. You can also change existing crypt key with a different cryptKey.
        Parameters:
        cryptKey - The new encryption key (no more than 16 bytes).
        Returns:
        True if success, otherwise False.

      • checkReSetCryptKey

        public void checkReSetCryptKey​(@Nullable
                               java.lang.String cryptKey)
        Just reset the encryption key (will not encrypt or decrypt anything). Usually you should call this method after another process has reKey(String) the multi-process MMKV instance.
        Parameters:
        cryptKey - The new encryption key (no more than 16 bytes).

      • pageSize

        public static int pageSize()
        Returns:
        The device's memory page size.

      • version

        public static java.lang.String version()
        Returns:
        The version of MMKV.

      • mmapID

        public java.lang.String mmapID()
        Returns:
        The unique ID of the MMKV instance.

      • lock

        public void lock()
        Exclusively inter-process lock the MMKV instance. It will block and wait until it successfully locks the file. It will make no effect if the MMKV instance is created with SINGLE_PROCESS_MODE.

      • unlock

        public void unlock()
        Exclusively inter-process unlock the MMKV instance. It will make no effect if the MMKV instance is created with SINGLE_PROCESS_MODE.

      • tryLock

        public boolean tryLock()
        Try exclusively inter-process lock the MMKV instance. It will not block if the file has already been locked by another process. It will make no effect if the MMKV instance is created with SINGLE_PROCESS_MODE.
        Returns:
        True if successfully locked, otherwise return immediately with False.

      • encode

        public boolean encode​(java.lang.String key,
                      boolean value)

      • encode

        public boolean encode​(java.lang.String key,
                      boolean value,
                      int expireDurationInSecond)
        Set value with customize expiration in sections.
        Parameters:
        expireDurationInSecond - override the default duration, ExpireNever (0) means never expire.

      • decodeBool

        public boolean decodeBool​(java.lang.String key)

      • decodeBool

        public boolean decodeBool​(java.lang.String key,
                          boolean defaultValue)

      • encode

        public boolean encode​(java.lang.String key,
                      int value)

      • encode

        public boolean encode​(java.lang.String key,
                      int value,
                      int expireDurationInSecond)
        Set value with customize expiration in sections.
        Parameters:
        expireDurationInSecond - override the default duration, ExpireNever (0) means never expire.

      • decodeInt

        public int decodeInt​(java.lang.String key)

      • decodeInt

        public int decodeInt​(java.lang.String key,
                     int defaultValue)

      • encode

        public boolean encode​(java.lang.String key,
                      long value)

      • encode

        public boolean encode​(java.lang.String key,
                      long value,
                      int expireDurationInSecond)
        Set value with customize expiration in sections.
        Parameters:
        expireDurationInSecond - override the default duration, ExpireNever (0) means never expire.

      • decodeLong

        public long decodeLong​(java.lang.String key)

      • decodeLong

        public long decodeLong​(java.lang.String key,
                       long defaultValue)

      • encode

        public boolean encode​(java.lang.String key,
                      float value)

      • encode

        public boolean encode​(java.lang.String key,
                      float value,
                      int expireDurationInSecond)
        Set value with customize expiration in sections.
        Parameters:
        expireDurationInSecond - override the default duration, ExpireNever (0) means never expire.

      • decodeFloat

        public float decodeFloat​(java.lang.String key)

      • decodeFloat

        public float decodeFloat​(java.lang.String key,
                         float defaultValue)

      • encode

        public boolean encode​(java.lang.String key,
                      double value)

      • encode

        public boolean encode​(java.lang.String key,
                      double value,
                      int expireDurationInSecond)
        Set value with customize expiration in sections.
        Parameters:
        expireDurationInSecond - override the default duration, ExpireNever (0) means never expire.

      • decodeDouble

        public double decodeDouble​(java.lang.String key)

      • decodeDouble

        public double decodeDouble​(java.lang.String key,
                           double defaultValue)

      • encode

        public boolean encode​(java.lang.String key,
                      @Nullable
                      java.lang.String value)

      • encode

        public boolean encode​(java.lang.String key,
                      @Nullable
                      java.lang.String value,
                      int expireDurationInSecond)
        Set value with customize expiration in sections.
        Parameters:
        expireDurationInSecond - override the default duration, ExpireNever (0) means never expire.

      • decodeString

        @Nullable
public java.lang.String decodeString​(java.lang.String key)

      • decodeString

        @Nullable
public java.lang.String decodeString​(java.lang.String key,
                                     @Nullable
                                     java.lang.String defaultValue)

      • encode

        public boolean encode​(java.lang.String key,
                      @Nullable
                      java.util.Set<java.lang.String> value)

      • encode

        public boolean encode​(java.lang.String key,
                      @Nullable
                      java.util.Set<java.lang.String> value,
                      int expireDurationInSecond)
        Set value with customize expiration in sections.
        Parameters:
        expireDurationInSecond - override the default duration, ExpireNever (0) means never expire.

      • decodeStringSet

        @Nullable
public java.util.Set<java.lang.String> decodeStringSet​(java.lang.String key)

      • decodeStringSet

        @Nullable
public java.util.Set<java.lang.String> decodeStringSet​(java.lang.String key,
                                                       @Nullable
                                                       java.util.Set<java.lang.String> defaultValue)

      • decodeStringSet

        @Nullable
public java.util.Set<java.lang.String> decodeStringSet​(java.lang.String key,
                                                       @Nullable
                                                       java.util.Set<java.lang.String> defaultValue,
                                                       java.lang.Class<? extends java.util.Set> cls)

      • encode

        public boolean encode​(java.lang.String key,
                      @Nullable
                      byte[] value)

      • encode

        public boolean encode​(java.lang.String key,
                      @Nullable
                      byte[] value,
                      int expireDurationInSecond)
        Set value with customize expiration in sections.
        Parameters:
        expireDurationInSecond - override the default duration, ExpireNever (0) means never expire.

      • decodeBytes

        @Nullable
public byte[] decodeBytes​(java.lang.String key)

      • decodeBytes

        @Nullable
public byte[] decodeBytes​(java.lang.String key,
                          @Nullable
                          byte[] defaultValue)

      • encode

        public boolean encode​(java.lang.String key,
                      @Nullable
                      android.os.Parcelable value)

      • encode

        public boolean encode​(java.lang.String key,
                      @Nullable
                      android.os.Parcelable value,
                      int expireDurationInSecond)
        Set value with customize expiration in sections.
        Parameters:
        expireDurationInSecond - override the default duration, ExpireNever (0) means never expire.

      • decodeParcelable

        @Nullable
public <T extends android.os.Parcelable> T decodeParcelable​(java.lang.String key,
                                                            java.lang.Class<T> tClass)

      • decodeParcelable

        @Nullable
public <T extends android.os.Parcelable> T decodeParcelable​(java.lang.String key,
                                                            java.lang.Class<T> tClass,
                                                            @Nullable
                                                            T defaultValue)

      • getValueSize

        public int getValueSize​(java.lang.String key)
        Get the actual size consumption of the key's value. Note: might be a little bigger than value's length.
        Parameters:
        key - The key of the value.

      • getValueActualSize

        public int getValueActualSize​(java.lang.String key)
        Get the actual size of the key's value. String's length or byte[]'s length, etc.
        Parameters:
        key - The key of the value.

      • containsKey

        public boolean containsKey​(java.lang.String key)
        Check whether or not MMKV contains the key.
        Parameters:
        key - The key of the value.

      • allKeys

        @Nullable
public java.lang.String[] allKeys()
        Returns:
        All the keys.

      • allNonExpireKeys

        @Nullable
public java.lang.String[] allNonExpireKeys()
        Returns:
        All non-expired keys. Note that this call has costs.

      • count

        public long count()
        Returns:
        The total count of all the keys.

      • countNonExpiredKeys

        public long countNonExpiredKeys()
        Returns:
        The total count of all non-expired keys. Note that this call has costs.

      • totalSize

        public long totalSize()
        Get the size of the underlying file. Align to the disk block size, typically 4K for an Android device.

      • actualSize

        public long actualSize()
        Get the actual used size of the MMKV instance. This size might increase and decrease as MMKV doing insertion and full write back.

      • removeValueForKey

        public void removeValueForKey​(java.lang.String key)

      • removeValuesForKeys

        public void removeValuesForKeys​(java.lang.String[] arrKeys)
        Batch remove some keys from the MMKV instance.
        Parameters:
        arrKeys - The keys to be removed.

      • clearAll

        public void clearAll()
        Clear all the key-values inside the MMKV instance.

      • trim

        public void trim()
        The totalSize() of an MMKV instance won't reduce after deleting key-values, call this method after lots of deleting if you care about disk usage. Note that clearAll() has a similar effect.

      • close

        public void close()
        Call this method if the MMKV instance is no longer needed in the near future. Any subsequent call to any MMKV instances with the same ID is undefined behavior.

      • clearMemoryCache

        public void clearMemoryCache()
        Clear memory cache of the MMKV instance. You can call it on memory warning. Any subsequent call to the MMKV instance will trigger all key-values loading from the file again.

      • sync

        public void sync()
        Save all mmap memory to file synchronously. You don't need to call this, really, I mean it. Unless you worry about the device running out of battery.

      • async

        public void async()
        Save all mmap memory to file asynchronously. No need to call this unless you worry about the device running out of battery.

      • isFileValid

        public static boolean isFileValid​(java.lang.String mmapID)
        Check whether the MMKV file is valid or not. Note: Don't use this to check the existence of the instance, the result is undefined on nonexistent files.

      • isFileValid

        public static boolean isFileValid​(java.lang.String mmapID,
                                  @Nullable
                                  java.lang.String rootPath)
        Check whether the MMKV file is valid or not on customize folder.
        Parameters:
        mmapID - The unique ID of the MMKV instance.
        rootPath - The folder of the MMKV instance, defaults to $(FilesDir)/mmkv.

      • importFromSharedPreferences

        public int importFromSharedPreferences​(android.content.SharedPreferences preferences)
        Atomically migrate all key-values from an existent SharedPreferences to the MMKV instance.
        Parameters:
        preferences - The SharedPreferences to import from.
        Returns:
        The total count of key-values imported.

      • backupOneToDirectory

        public static boolean backupOneToDirectory​(java.lang.String mmapID,
                                           java.lang.String dstDir,
                                           @Nullable
                                           java.lang.String rootPath)
        backup one MMKV instance to dstDir
        Parameters:
        mmapID - the MMKV ID to backup
        rootPath - the customize root path of the MMKV, if null then backup from the root dir of MMKV
        dstDir - the backup destination directory

      • restoreOneMMKVFromDirectory

        public static boolean restoreOneMMKVFromDirectory​(java.lang.String mmapID,
                                                  java.lang.String srcDir,
                                                  @Nullable
                                                  java.lang.String rootPath)
        restore one MMKV instance from srcDir
        Parameters:
        mmapID - the MMKV ID to restore
        srcDir - the restore source directory
        rootPath - the customize root path of the MMKV, if null then restore to the root dir of MMKV

      • backupAllToDirectory

        public static long backupAllToDirectory​(java.lang.String dstDir)
        backup all MMKV instance to dstDir
        Parameters:
        dstDir - the backup destination directory
        Returns:
        count of MMKV successfully backuped

      • restoreAllFromDirectory

        public static long restoreAllFromDirectory​(java.lang.String srcDir)
        restore all MMKV instance from srcDir
        Parameters:
        srcDir - the restore source directory
        Returns:
        count of MMKV successfully restored

      • enableAutoKeyExpire

        public boolean enableAutoKeyExpire​(int expireDurationInSecond)
        Enable auto key expiration. This is a upgrade operation, the file format will change. And the file won't be accessed correctly by older version (v1.2.16) of MMKV.
        Parameters:
        expireDurationInSecond - the expire duration for all keys, ExpireNever (0) means no default duration (aka each key will have it's own expire date)

      • disableAutoKeyExpire

        public boolean disableAutoKeyExpire()
        Disable auto key expiration. This is a downgrade operation.

      • getAll

        public java.util.Map<java.lang.String,​?> getAll()
        Intentionally Not Supported. Because MMKV does type-eraser inside to get better performance.
        Specified by:
        getAll in interface android.content.SharedPreferences

      • getString

        @Nullable
public java.lang.String getString​(java.lang.String key,
                                  @Nullable
                                  java.lang.String defValue)
        Specified by:
        getString in interface android.content.SharedPreferences

      • putString

        public android.content.SharedPreferences.Editor putString​(java.lang.String key,
                                                          @Nullable
                                                          java.lang.String value)
        Specified by:
        putString in interface android.content.SharedPreferences.Editor

      • putString

        public android.content.SharedPreferences.Editor putString​(java.lang.String key,
                                                          @Nullable
                                                          java.lang.String value,
                                                          int expireDurationInSecond)

      • getStringSet

        @Nullable
public java.util.Set<java.lang.String> getStringSet​(java.lang.String key,
                                                    @Nullable
                                                    java.util.Set<java.lang.String> defValues)
        Specified by:
        getStringSet in interface android.content.SharedPreferences

      • putStringSet

        public android.content.SharedPreferences.Editor putStringSet​(java.lang.String key,
                                                             @Nullable
                                                             java.util.Set<java.lang.String> values)
        Specified by:
        putStringSet in interface android.content.SharedPreferences.Editor

      • putStringSet

        public android.content.SharedPreferences.Editor putStringSet​(java.lang.String key,
                                                             @Nullable
                                                             java.util.Set<java.lang.String> values,
                                                             int expireDurationInSecond)

      • putBytes

        public android.content.SharedPreferences.Editor putBytes​(java.lang.String key,
                                                         @Nullable
                                                         byte[] bytes)

      • putBytes

        public android.content.SharedPreferences.Editor putBytes​(java.lang.String key,
                                                         @Nullable
                                                         byte[] bytes,
                                                         int expireDurationInSecond)

      • getBytes

        public byte[] getBytes​(java.lang.String key,
                       @Nullable
                       byte[] defValue)

      • getInt

        public int getInt​(java.lang.String key,
                  int defValue)
        Specified by:
        getInt in interface android.content.SharedPreferences

      • putInt

        public android.content.SharedPreferences.Editor putInt​(java.lang.String key,
                                                       int value)
        Specified by:
        putInt in interface android.content.SharedPreferences.Editor

      • putInt

        public android.content.SharedPreferences.Editor putInt​(java.lang.String key,
                                                       int value,
                                                       int expireDurationInSecond)

      • getLong

        public long getLong​(java.lang.String key,
                    long defValue)
        Specified by:
        getLong in interface android.content.SharedPreferences

      • putLong

        public android.content.SharedPreferences.Editor putLong​(java.lang.String key,
                                                        long value)
        Specified by:
        putLong in interface android.content.SharedPreferences.Editor

      • putLong

        public android.content.SharedPreferences.Editor putLong​(java.lang.String key,
                                                        long value,
                                                        int expireDurationInSecond)

      • getFloat

        public float getFloat​(java.lang.String key,
                      float defValue)
        Specified by:
        getFloat in interface android.content.SharedPreferences

      • putFloat

        public android.content.SharedPreferences.Editor putFloat​(java.lang.String key,
                                                         float value)
        Specified by:
        putFloat in interface android.content.SharedPreferences.Editor

      • putFloat

        public android.content.SharedPreferences.Editor putFloat​(java.lang.String key,
                                                         float value,
                                                         int expireDurationInSecond)

      • getBoolean

        public boolean getBoolean​(java.lang.String key,
                          boolean defValue)
        Specified by:
        getBoolean in interface android.content.SharedPreferences

      • putBoolean

        public android.content.SharedPreferences.Editor putBoolean​(java.lang.String key,
                                                           boolean value)
        Specified by:
        putBoolean in interface android.content.SharedPreferences.Editor

      • putBoolean

        public android.content.SharedPreferences.Editor putBoolean​(java.lang.String key,
                                                           boolean value,
                                                           int expireDurationInSecond)

      • remove

        public android.content.SharedPreferences.Editor remove​(java.lang.String key)
        Specified by:
        remove in interface android.content.SharedPreferences.Editor

      • clear

        public android.content.SharedPreferences.Editor clear()
        clearAll()
        Specified by:
        clear in interface android.content.SharedPreferences.Editor

      • commit

        @Deprecated
public boolean commit()
        Deprecated.
        This method is only for compatibility purpose. You should remove all the calls after migration to MMKV. MMKV doesn't rely on commit() to save data to file. If you really worry about losing battery and data corruption, call async() or sync() instead.
        Specified by:
        commit in interface android.content.SharedPreferences.Editor

      • apply

        @Deprecated
public void apply()
        Deprecated.
        This method is only for compatibility purpose. You should remove all the calls after migration to MMKV. MMKV doesn't rely on apply() to save data to file. If you really worry about losing battery and data corruption, call async() instead.
        Specified by:
        apply in interface android.content.SharedPreferences.Editor

      • contains

        public boolean contains​(java.lang.String key)
        Specified by:
        contains in interface android.content.SharedPreferences

      • edit

        public android.content.SharedPreferences.Editor edit()
        Specified by:
        edit in interface android.content.SharedPreferences

      • registerOnSharedPreferenceChangeListener

        public void registerOnSharedPreferenceChangeListener​(android.content.SharedPreferences.OnSharedPreferenceChangeListener listener)
        Intentionally Not Supported by MMKV. We believe it's better not for a storage framework to notify the change of data. Check registerContentChangeNotify(com.tencent.mmkv.MMKVContentChangeNotification) for a potential replacement on inter-process scene.
        Specified by:
        registerOnSharedPreferenceChangeListener in interface android.content.SharedPreferences

      • unregisterOnSharedPreferenceChangeListener

        public void unregisterOnSharedPreferenceChangeListener​(android.content.SharedPreferences.OnSharedPreferenceChangeListener listener)
        Intentionally Not Supported by MMKV. We believe it's better not for a storage framework to notify the change of data.
        Specified by:
        unregisterOnSharedPreferenceChangeListener in interface android.content.SharedPreferences

      • mmkvWithAshmemFD

        public static MMKV mmkvWithAshmemFD​(java.lang.String mmapID,
                                    int fd,
                                    int metaFD,
                                    java.lang.String cryptKey)
                             throws java.lang.RuntimeException
        Get an ashmem MMKV instance that has been initiated by another process. Normally you should just call mmkvWithAshmemID(Context, String, int, int, String) instead.
        Parameters:
        mmapID - The unique ID of the MMKV instance.
        fd - The file descriptor of the ashmem of the MMKV file, transferred from another process by binder.
        metaFD - The file descriptor of the ashmem of the MMKV crc file, transferred from another process by binder.
        cryptKey - The encryption key of the MMKV instance (no more than 16 bytes).
        Throws:
        java.lang.RuntimeException - If any failure in JNI or runtime.

      • ashmemFD

        public int ashmemFD()
        Returns:
        The file descriptor of the ashmem of the MMKV file.

      • ashmemMetaFD

        public int ashmemMetaFD()
        Returns:
        The file descriptor of the ashmem of the MMKV crc file.

      • createNativeBuffer

        @Nullable
public static NativeBuffer createNativeBuffer​(int size)
        Create an native buffer, whose underlying memory can be directly transferred to another JNI method. Avoiding unnecessary JNI boxing and unboxing. An NativeBuffer must be manually destroyNativeBuffer(com.tencent.mmkv.NativeBuffer) to avoid memory leak.
        Parameters:
        size - The size of the underlying memory.

      • destroyNativeBuffer

        public static void destroyNativeBuffer​(NativeBuffer buffer)
        Destroy the native buffer. An NativeBuffer must be manually destroy to avoid memory leak.

      • writeValueToNativeBuffer

        public int writeValueToNativeBuffer​(java.lang.String key,
                                    NativeBuffer buffer)
        Write the value of the key to the native buffer.
        Returns:
        The size written. Return -1 on any error.

      • unregisterHandler

        public static void unregisterHandler()
        Unregister the handler for MMKV.

      • registerContentChangeNotify

        public static void registerContentChangeNotify​(MMKVContentChangeNotification notify)
        Register for MMKV inter-process content change notification. The notification will trigger only when any method is manually called on the MMKV instance. For example checkContentChangedByOuterProcess().
        Parameters:
        notify - The notification handler.

      • unregisterContentChangeNotify

        public static void unregisterContentChangeNotify()
        Unregister for MMKV inter-process content change notification.

      • checkContentChangedByOuterProcess

        public void checkContentChangedByOuterProcess()
        Check inter-process content change manually.