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Pods/Realm/include/core/realm.h 113 KB
75d24c15   yangbin   123
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  /*
      FIXME: License, since this header may be distributed independently from
      other headers.
  */
  
  #ifndef REALM_H
  #define REALM_H
  
  #include <stddef.h>
  #include <stdint.h>
  #include <stdbool.h>
  
  #if defined(_WIN32) || defined(__CYGWIN__)
  
  #if defined(Realm_EXPORTS)
  // Exporting Win32 symbols
  #define RLM_EXPORT __declspec(dllexport)
  #else
  // Importing Win32 symbols. Note: Clients linking statically should define
  // RLM_NO_DLLIMPORT.
  #if !defined(RLM_NO_DLLIMPORT)
  #define RLM_EXPORT __declspec(dllimport)
  #else
  #define RLM_EXPORT
  #endif // RLM_NO_DLLIMPORT
  #endif // Realm_EXPORTS
  
  #else
  // Not Win32
  #define RLM_EXPORT __attribute__((visibility("default")))
  #endif
  
  #ifdef __cplusplus
  #define RLM_API extern "C" RLM_EXPORT
  #define RLM_API_NOEXCEPT noexcept
  #else
  #define RLM_API RLM_EXPORT
  #define RLM_API_NOEXCEPT
  #endif // __cplusplus
  
  // Some platforms don't support anonymous unions in structs.
  // RLM_NO_ANON_UNIONS allows definining a member name for unions in structs where
  // RLM_ANON_UNION_MEMBER(name) is used.
  #ifdef RLM_NO_ANON_UNIONS
  #define RLM_ANON_UNION_MEMBER(name) name
  #else
  #define RLM_ANON_UNION_MEMBER(name)
  #endif
  
  typedef struct shared_realm realm_t;
  typedef struct realm_schema realm_schema_t;
  typedef struct realm_scheduler realm_scheduler_t;
  typedef struct realm_thread_safe_reference realm_thread_safe_reference_t;
  typedef void (*realm_free_userdata_func_t)(void*);
  typedef void* (*realm_clone_userdata_func_t)(const void*);
  
  /* Accessor types */
  typedef struct realm_object realm_object_t;
  typedef struct realm_list realm_list_t;
  typedef struct realm_set realm_set_t;
  typedef struct realm_dictionary realm_dictionary_t;
  
  /* Query types */
  typedef struct realm_query realm_query_t;
  typedef struct realm_results realm_results_t;
  
  /* Config types */
  typedef struct realm_config realm_config_t;
  typedef struct realm_app_config realm_app_config_t;
  typedef struct realm_sync_client_config realm_sync_client_config_t;
  typedef struct realm_sync_config realm_sync_config_t;
  typedef bool (*realm_migration_func_t)(void* userdata, realm_t* old_realm, realm_t* new_realm,
                                         const realm_schema_t* schema);
  typedef bool (*realm_data_initialization_func_t)(void* userdata, realm_t* realm);
  typedef bool (*realm_should_compact_on_launch_func_t)(void* userdata, uint64_t total_bytes, uint64_t used_bytes);
  typedef enum realm_schema_mode {
      RLM_SCHEMA_MODE_AUTOMATIC,
      RLM_SCHEMA_MODE_IMMUTABLE,
      RLM_SCHEMA_MODE_READ_ONLY_ALTERNATIVE,
      RLM_SCHEMA_MODE_RESET_FILE,
      RLM_SCHEMA_MODE_ADDITIVE_DISCOVERED,
      RLM_SCHEMA_MODE_ADDITIVE_EXPLICIT,
      RLM_SCHEMA_MODE_MANUAL,
  } realm_schema_mode_e;
  
  /* Key types */
  typedef uint32_t realm_class_key_t;
  typedef int64_t realm_property_key_t;
  typedef int64_t realm_object_key_t;
  typedef uint64_t realm_version_t;
  
  static const realm_class_key_t RLM_INVALID_CLASS_KEY = ((uint32_t)-1) >> 1;
  static const realm_property_key_t RLM_INVALID_PROPERTY_KEY = -1;
  static const realm_object_key_t RLM_INVALID_OBJECT_KEY = -1;
  
  /* Value types */
  
  typedef enum realm_value_type {
      RLM_TYPE_NULL,
      RLM_TYPE_INT,
      RLM_TYPE_BOOL,
      RLM_TYPE_STRING,
      RLM_TYPE_BINARY,
      RLM_TYPE_TIMESTAMP,
      RLM_TYPE_FLOAT,
      RLM_TYPE_DOUBLE,
      RLM_TYPE_DECIMAL128,
      RLM_TYPE_OBJECT_ID,
      RLM_TYPE_LINK,
      RLM_TYPE_UUID,
  } realm_value_type_e;
  
  typedef enum realm_schema_validation_mode {
      RLM_SCHEMA_VALIDATION_BASIC = 0,
      RLM_SCHEMA_VALIDATION_SYNC = 1,
      RLM_SCHEMA_VALIDATION_REJECT_EMBEDDED_ORPHANS = 2
  } realm_schema_validation_mode_e;
  
  typedef struct realm_string {
      const char* data;
      size_t size;
  } realm_string_t;
  
  typedef struct realm_binary {
      const uint8_t* data;
      size_t size;
  } realm_binary_t;
  
  typedef struct realm_timestamp {
      int64_t seconds;
      int32_t nanoseconds;
  } realm_timestamp_t;
  
  typedef struct realm_decimal128 {
      uint64_t w[2];
  } realm_decimal128_t;
  
  typedef struct realm_link {
      realm_class_key_t target_table;
      realm_object_key_t target;
  } realm_link_t;
  
  typedef struct realm_object_id {
      uint8_t bytes[12];
  } realm_object_id_t;
  
  typedef struct realm_uuid {
      uint8_t bytes[16];
  } realm_uuid_t;
  
  typedef struct realm_value {
      union {
          int64_t integer;
          bool boolean;
          realm_string_t string;
          realm_binary_t binary;
          realm_timestamp_t timestamp;
          float fnum;
          double dnum;
          realm_decimal128_t decimal128;
          realm_object_id_t object_id;
          realm_uuid_t uuid;
  
          realm_link_t link;
  
          char data[16];
      } RLM_ANON_UNION_MEMBER(values);
      realm_value_type_e type;
  } realm_value_t;
  
  typedef struct realm_version_id {
      uint64_t version;
      uint64_t index;
  } realm_version_id_t;
  
  
  /* Error types */
  typedef struct realm_async_error realm_async_error_t;
  typedef enum realm_errno {
      RLM_ERR_NONE = 0,
      RLM_ERR_UNKNOWN,
      RLM_ERR_OTHER_EXCEPTION,
      RLM_ERR_OUT_OF_MEMORY,
      RLM_ERR_NOT_CLONABLE,
  
      RLM_ERR_NOT_IN_A_TRANSACTION,
      RLM_ERR_WRONG_THREAD,
  
      RLM_ERR_INVALIDATED_OBJECT,
      RLM_ERR_INVALID_PROPERTY,
      RLM_ERR_MISSING_PROPERTY_VALUE,
      RLM_ERR_PROPERTY_TYPE_MISMATCH,
      RLM_ERR_MISSING_PRIMARY_KEY,
      RLM_ERR_UNEXPECTED_PRIMARY_KEY,
      RLM_ERR_WRONG_PRIMARY_KEY_TYPE,
      RLM_ERR_MODIFY_PRIMARY_KEY,
      RLM_ERR_READ_ONLY_PROPERTY,
      RLM_ERR_PROPERTY_NOT_NULLABLE,
      RLM_ERR_INVALID_ARGUMENT,
  
      RLM_ERR_LOGIC,
      RLM_ERR_NO_SUCH_TABLE,
      RLM_ERR_NO_SUCH_OBJECT,
      RLM_ERR_CROSS_TABLE_LINK_TARGET,
      RLM_ERR_UNSUPPORTED_FILE_FORMAT_VERSION,
      RLM_ERR_MULTIPLE_SYNC_AGENTS,
      RLM_ERR_ADDRESS_SPACE_EXHAUSTED,
      RLM_ERR_MAXIMUM_FILE_SIZE_EXCEEDED,
      RLM_ERR_OUT_OF_DISK_SPACE,
      RLM_ERR_KEY_NOT_FOUND,
      RLM_ERR_COLUMN_NOT_FOUND,
      RLM_ERR_COLUMN_ALREADY_EXISTS,
      RLM_ERR_KEY_ALREADY_USED,
      RLM_ERR_SERIALIZATION_ERROR,
      RLM_ERR_INVALID_PATH_ERROR,
      RLM_ERR_DUPLICATE_PRIMARY_KEY_VALUE,
  
      RLM_ERR_INDEX_OUT_OF_BOUNDS,
  
      RLM_ERR_INVALID_QUERY_STRING,
      RLM_ERR_INVALID_QUERY,
  
      RLM_ERR_CALLBACK = 1000000, /**< A user-provided callback failed. */
  } realm_errno_e;
  
  typedef enum realm_logic_error_kind {
      RLM_LOGIC_ERR_NONE = 0,
      RLM_LOGIC_ERR_STRING_TOO_BIG,
      // ...
  } realm_logic_error_kind_e;
  
  typedef struct realm_error {
      realm_errno_e error;
      const char* message;
      union {
          int code;
          realm_logic_error_kind_e logic_error_kind;
      } kind;
  } realm_error_t;
  
  /* Schema types */
  
  typedef enum realm_column_attr {
      // Values matching `realm::ColumnAttr`.
      RLM_COLUMN_ATTR_NONE = 0,
      RLM_COLUMN_ATTR_INDEXED = 1,
      RLM_COLUMN_ATTR_UNIQUE = 2,
      RLM_COLUMN_ATTR_RESERVED = 4,
      RLM_COLUMN_ATTR_STRONG_LINKS = 8,
      RLM_COLUMN_ATTR_NULLABLE = 16,
      RLM_COLUMN_ATTR_LIST = 32,
      RLM_COLUMN_ATTR_DICTIONARY = 64,
      RLM_COLUMN_ATTR_COLLECTION = 64 + 32,
  } realm_column_attr_e;
  
  typedef enum realm_property_type {
      // Values matching `realm::ColumnType`.
      RLM_PROPERTY_TYPE_INT = 0,
      RLM_PROPERTY_TYPE_BOOL = 1,
      RLM_PROPERTY_TYPE_STRING = 2,
      RLM_PROPERTY_TYPE_BINARY = 4,
      RLM_PROPERTY_TYPE_MIXED = 6,
      RLM_PROPERTY_TYPE_TIMESTAMP = 8,
      RLM_PROPERTY_TYPE_FLOAT = 9,
      RLM_PROPERTY_TYPE_DOUBLE = 10,
      RLM_PROPERTY_TYPE_DECIMAL128 = 11,
      RLM_PROPERTY_TYPE_OBJECT = 12,
      RLM_PROPERTY_TYPE_LINKING_OBJECTS = 14,
      RLM_PROPERTY_TYPE_OBJECT_ID = 15,
      RLM_PROPERTY_TYPE_UUID = 17,
  } realm_property_type_e;
  
  typedef enum realm_collection_type {
      RLM_COLLECTION_TYPE_NONE = 0,
      RLM_COLLECTION_TYPE_LIST = 1,
      RLM_COLLECTION_TYPE_SET = 2,
      RLM_COLLECTION_TYPE_DICTIONARY = 4,
  } realm_collection_type_e;
  
  typedef struct realm_property_info {
      const char* name;
      const char* public_name;
      realm_property_type_e type;
      realm_collection_type_e collection_type;
  
      const char* link_target;
      const char* link_origin_property_name;
      realm_property_key_t key;
      int flags;
  } realm_property_info_t;
  
  typedef struct realm_class_info {
      const char* name;
      const char* primary_key;
      size_t num_properties;
      size_t num_computed_properties;
      realm_class_key_t key;
      int flags;
  } realm_class_info_t;
  
  typedef enum realm_class_flags {
      RLM_CLASS_NORMAL = 0,
      RLM_CLASS_EMBEDDED = 1,
  } realm_class_flags_e;
  
  typedef enum realm_property_flags {
      RLM_PROPERTY_NORMAL = 0,
      RLM_PROPERTY_NULLABLE = 1,
      RLM_PROPERTY_PRIMARY_KEY = 2,
      RLM_PROPERTY_INDEXED = 4,
  } realm_property_flags_e;
  
  
  /* Notification types */
  typedef struct realm_notification_token realm_notification_token_t;
  typedef struct realm_object_changes realm_object_changes_t;
  typedef struct realm_collection_changes realm_collection_changes_t;
  typedef void (*realm_on_object_change_func_t)(void* userdata, const realm_object_changes_t*);
  typedef void (*realm_on_collection_change_func_t)(void* userdata, const realm_collection_changes_t*);
  typedef void (*realm_callback_error_func_t)(void* userdata, const realm_async_error_t*);
  typedef void (*realm_on_realm_change_func_t)(void* userdata);
  
  /**
   * Callback for realm schema changed notifications.
   *
   * @param new_schema The new schema. This object is released after the callback returns.
   *                   Preserve it with realm_clone() if you wish to keep it around for longer.
   */
  typedef void (*realm_on_schema_change_func_t)(void* userdata, const realm_schema_t* new_schema);
  
  /* Scheduler types */
  typedef void (*realm_scheduler_notify_func_t)(void* userdata);
  typedef bool (*realm_scheduler_is_on_thread_func_t)(void* userdata);
  typedef bool (*realm_scheduler_is_same_as_func_t)(const void* userdata1, const void* userdata2);
  typedef bool (*realm_scheduler_can_deliver_notifications_func_t)(void* userdata);
  typedef void (*realm_scheduler_set_notify_callback_func_t)(void* userdata, void* callback_userdata,
                                                             realm_free_userdata_func_t, realm_scheduler_notify_func_t);
  typedef realm_scheduler_t* (*realm_scheduler_default_factory_func_t)(void* userdata);
  
  /**
   * Get the VersionID of the current transaction.
   *
   * @param out_found True if version information is available. This requires an available Read or Write transaction.
   * @param out_version The version of the current transaction. If `out_found` returns False, this returns (0,0).
   * @return True if no exception occurred.
   */
  RLM_API bool realm_get_version_id(const realm_t*, bool* out_found, realm_version_id_t* out_version);
  
  /**
   * Get a string representing the version number of the Realm library.
   *
   * @return A null-terminated string.
   */
  RLM_API const char* realm_get_library_version(void);
  
  /**
   * Get individual components of the version number of the Realm library.
   *
   * @param out_major The major version number (X.0.0).
   * @param out_minor The minor version number (0.X.0).
   * @param out_patch The patch version number (0.0.X).
   * @param out_extra The extra version string (0.0.0-X).
   */
  RLM_API void realm_get_library_version_numbers(int* out_major, int* out_minor, int* out_patch,
                                                 const char** out_extra);
  
  /**
   * Get the last error that happened on this thread.
   *
   * Errors are thread-local. Getting the error must happen on the same thread as
   * the call that caused the error to occur. The error is specific to the current
   * thread, and not the Realm instance for which the error occurred.
   *
   * Note: The error message in @a err will only be safe to use until the next API
   *       call is made on the current thread.
   *
   * Note: The error is not cleared by subsequent successful calls to this
   *       function, but it will be overwritten by subsequent failing calls to
   *       other library functions.
   *
   * Note: Calling this function does not clear the current last error.
   *
   * This function does not allocate any memory.
   *
   * @param err A pointer to a `realm_error_t` struct that will be populated with
   *            information about the last error, if there is one. May be NULL.
   * @return True if an error occurred.
   */
  RLM_API bool realm_get_last_error(realm_error_t* err);
  
  /**
   * Get information about an async error, potentially coming from another thread.
   *
   * This function does not allocate any memory.
   *
   * @param err A pointer to a `realm_error_t` struct that will be populated with
   *            information about the error. May not be NULL.
   * @see realm_get_last_error()
   */
  RLM_API void realm_get_async_error(const realm_async_error_t* err, realm_error_t* out_err);
  
  /**
   * Convert the last error to `realm_async_error_t`, which can safely be passed
   * between threads.
   *
   * Note: This function does not clear the last error.
   *
   * @return A non-null pointer if there was an error on this thread.
   * @see realm_get_last_error()
   * @see realm_get_async_error()
   * @see realm_clear_last_error()
   */
  RLM_API realm_async_error_t* realm_get_last_error_as_async_error(void);
  
  #if defined(__cplusplus)
  /**
   * Rethrow the last exception.
   *
   * Note: This function does not have C linkage, because throwing across language
   * boundaries is undefined behavior. When called from C code, this should result
   * in a linker error. When called from C++, `std::rethrow_exception` will be
   * called to propagate the exception unchanged.
   */
  RLM_EXPORT void realm_rethrow_last_error(void);
  
  /**
   * Invoke a function that may throw an exception, and report that exception as
   * part of the C API error handling mechanism.
   *
   * This is used to test translation of exceptions to error codes.
   *
   * @return True if no exception was thrown.
   */
  RLM_EXPORT bool realm_wrap_exceptions(void (*)()) noexcept;
  #endif // __cplusplus
  
  /**
   * Clear the last error on the calling thread.
   *
   * Use this if the system has recovered from an error, e.g. by closing the
   * offending Realm and reopening it, freeing up resources, or similar.
   *
   * @return True if an error was cleared.
   */
  RLM_API bool realm_clear_last_error(void);
  
  /**
   * Free memory allocated by the module this library was linked into.
   *
   * This is needed for raw memory buffers such as string copies or arrays
   * returned from a library function. Realm C Wrapper objects on the other hand
   * should always be freed with realm_release() only.
   */
  RLM_API void realm_free(void* buffer);
  
  /**
   * Free any Realm C Wrapper object.
   *
   * Note: Any pointer returned from a library function is owned by the caller.
   *       The caller is responsible for calling `realm_release()`. The only
   *       exception from this is C++ bridge functions that return `void*`, with
   *       the prefix `_realm`.
   *
   * Note: C++ destructors are typically `noexcept`, so it is likely that an
   *       exception will crash the process.
   *
   * @param ptr A pointer to a Realm C Wrapper object. May be NULL.
   */
  RLM_API void realm_release(void* ptr);
  
  /**
   * Clone a Realm C Wrapper object.
   *
   * If the object is not clonable, this function fails with RLM_ERR_NOT_CLONABLE.
   *
   * @return A pointer to an object of the same type as the input, or NULL if
   *         cloning failed.
   */
  RLM_API void* realm_clone(const void*);
  
  /**
   * Return true if two API objects refer to the same underlying data. Objects
   * with different types are never equal.
   *
   * Note: This function cannot be used with types that have value semantics, only
   *       opaque types that have object semantics.
   *
   *    - `realm_t` objects are identical if they represent the same instance (not
   *      just if they represent the same file).
   *    - `realm_schema_t` objects are equal if the represented schemas are equal.
   *    - `realm_config_t` objects are equal if the configurations are equal.
   *    - `realm_object_t` objects are identical if they belong to the same realm
   *      and class, and have the same object key.
   *    - `realm_list_t` and other collection objects are identical if they come
   *      from the same object and property.
   *    - `realm_query_t` objects are never equal.
   *    - `realm_scheduler_t` objects are equal if they represent the same
   *      scheduler.
   *    - Query descriptor objects are equal if they represent equivalent
   *      descriptors.
   *    - `realm_async_error_t` objects are equal if they represent the same
   *      exception instance.
   *
   * This function cannot fail.
   */
  RLM_API bool realm_equals(const void*, const void*);
  
  /**
   * True if a Realm C Wrapper object is "frozen" (immutable).
   *
   * Objects, collections, and results can be frozen. For all other types, this
   * function always returns false.
   */
  RLM_API bool realm_is_frozen(const void*);
  
  /**
   * Get a thread-safe reference representing the same underlying object as some
   * API object.
   *
   * The thread safe reference can be passed to a different thread and resolved
   * against a different `realm_t` instance, which succeeds if the underlying
   * object still exists.
   *
   * The following types can produce thread safe references:
   *
   * - `realm_object_t`
   * - `realm_results_t`
   * - `realm_list_t`
   * - `realm_t`
   *
   * This does not assume ownership of the object, except for `realm_t`, where the
   * instance is transferred by value, and must be transferred back to the current
   * thread to be used. Note that the `realm_thread_safe_reference_t` object must
   * still be destroyed after having been converted into a `realm_t` object.
   *
   * @return A non-null pointer if no exception occurred.
   */
  RLM_API realm_thread_safe_reference_t* realm_create_thread_safe_reference(const void*);
  
  /**
   * Allocate a new configuration with default options.
   */
  RLM_API realm_config_t* realm_config_new(void);
  
  /**
   * Get the path of the realm being opened.
   *
   * This function cannot fail.
   */
  RLM_API const char* realm_config_get_path(const realm_config_t*);
  
  /**
   * Set the path of the realm being opened.
   *
   * This function aborts when out of memory, but otherwise cannot fail.
   */
  RLM_API void realm_config_set_path(realm_config_t*, const char* path);
  
  /**
   * Get the encryption key for the realm.
   *
   * The output buffer must be at least 64 bytes.
   *
   * @returns The length of the encryption key (0 or 64)
   */
  RLM_API size_t realm_config_get_encryption_key(const realm_config_t*, uint8_t* out_key);
  
  /**
   * Set the encryption key for the realm.
   *
   * The key must be either 64 bytes long or have length zero (in which case
   * encryption is disabled).
   *
   * This function may fail if the encryption key has the wrong length.
   */
  RLM_API bool realm_config_set_encryption_key(realm_config_t*, const uint8_t* key, size_t key_size);
  
  /**
   * Get the schema for this realm.
   *
   * Note: The caller obtains ownership of the returned value, and must manually
   *       free it by calling `realm_release()`.
   *
   * @return A schema object, or NULL if the schema is not set (empty).
   */
  RLM_API realm_schema_t* realm_config_get_schema(const realm_config_t*);
  
  /**
   * Set the schema object for this realm.
   *
   * This does not take ownership of the schema object, and it should be released
   * afterwards.
   *
   * This function aborts when out of memory, but otherwise cannot fail.
   *
   * @param schema The schema object. May be NULL, which means an empty schema.
   */
  RLM_API void realm_config_set_schema(realm_config_t*, const realm_schema_t* schema);
  
  /**
   * Get the schema version of the schema.
   *
   * This function cannot fail.
   */
  RLM_API uint64_t realm_config_get_schema_version(const realm_config_t*);
  
  /**
   * Set the schema version of the schema.
   *
   * This function cannot fail.
   */
  RLM_API void realm_config_set_schema_version(realm_config_t*, uint64_t version);
  
  /**
   * Get the schema mode.
   *
   * This function cannot fail.
   */
  RLM_API realm_schema_mode_e realm_config_get_schema_mode(const realm_config_t*);
  
  /**
   * Set the schema mode.
   *
   * This function cannot fail.
   */
  RLM_API void realm_config_set_schema_mode(realm_config_t*, realm_schema_mode_e);
  
  /**
   * Set the migration callback.
   *
   * The migration function is called during a migration for schema modes
   * `RLM_SCHEMA_MODE_AUTOMATIC` and `RLM_SCHEMA_MODE_MANUAL`. The callback is
   * invoked with a realm instance before the migration and the realm instance
   * that is currently performing the migration.
   *
   * This function cannot fail.
   */
  RLM_API void realm_config_set_migration_function(realm_config_t*, realm_migration_func_t, void* userdata);
  
  /**
   * Set the data initialization function.
   *
   * The callback is invoked the first time the schema is created, such that the
   * user can perform one-time initialization of the data in the realm.
   *
   * The realm instance passed to the callback is in a write transaction.
   *
   * This function cannot fail.
   */
  RLM_API void realm_config_set_data_initialization_function(realm_config_t*, realm_data_initialization_func_t,
                                                             void* userdata);
  
  /**
   * Set the should-compact-on-launch callback.
   *
   * The callback is invoked the first time a realm file is opened in this process
   * to decide whether the realm file should be compacted.
   *
   * Note: If another process has the realm file open, it will not be compacted.
   *
   * This function cannot fail.
   */
  RLM_API void realm_config_set_should_compact_on_launch_function(realm_config_t*,
                                                                  realm_should_compact_on_launch_func_t,
                                                                  void* userdata);
  
  /**
   * True if file format upgrades on open are disabled.
   *
   * This function cannot fail.
   */
  RLM_API bool realm_config_get_disable_format_upgrade(const realm_config_t*);
  
  /**
   * Disable file format upgrade on open (default: false).
   *
   * If a migration is needed to open the realm file with the provided schema, an
   * error is thrown rather than automatically performing the migration.
   *
   * This function cannot fail.
   */
  RLM_API void realm_config_set_disable_format_upgrade(realm_config_t*, bool);
  
  /**
   * True if automatic change notifications should be generated.
   *
   * This function cannot fail.
   */
  RLM_API bool realm_config_get_automatic_change_notifications(const realm_config_t*);
  
  /**
   * Automatically generated change notifications (default: true).
   *
   * This function cannot fail.
   */
  RLM_API void realm_config_set_automatic_change_notifications(realm_config_t*, bool);
  
  /**
   * The scheduler which this realm should be bound to (default: NULL).
   *
   * If NULL, the realm will be bound to the default scheduler for the current thread.
   *
   * This function aborts when out of memory, but otherwise cannot fail.
   */
  RLM_API void realm_config_set_scheduler(realm_config_t*, const realm_scheduler_t*);
  
  /**
   * Sync configuration for this realm (default: NULL).
   *
   * This function aborts when out of memory, but otherwise cannot fail.
   */
  RLM_API void realm_config_set_sync_config(realm_config_t*, realm_sync_config_t*);
  
  /**
   * Get whether the realm file should be forcibly initialized as a synchronized.
   *
   * This function cannot fail.
   */
  RLM_API bool realm_config_get_force_sync_history(const realm_config_t*);
  
  /**
   * Force the realm file to be initialized as a synchronized realm, even if no
   * sync config is provided (default: false).
   *
   * This function cannot fail.
   */
  RLM_API void realm_config_set_force_sync_history(realm_config_t*, bool);
  
  /**
   * Set the audit interface for the realm (unimplemented).
   */
  RLM_API bool realm_config_set_audit_factory(realm_config_t*, void*);
  
  /**
   * Get maximum number of active versions in the realm file allowed before an
   * exception is thrown.
   *
   * This function cannot fail.
   */
  RLM_API uint64_t realm_config_get_max_number_of_active_versions(const realm_config_t*);
  
  /**
   * Set maximum number of active versions in the realm file allowed before an
   * exception is thrown (default: UINT64_MAX).
   *
   * This function cannot fail.
   */
  RLM_API void realm_config_set_max_number_of_active_versions(realm_config_t*, uint64_t);
  
  /**
   * Create a custom scheduler object from callback functions.
   *
   * @param userdata Pointer passed to all callbacks.
   * @param notify Function to trigger a call to the registered callback on the
   *               scheduler's event loop. This function must be thread-safe, or
   *               NULL, in which case the scheduler is considered unable to
   *               deliver notifications.
   * @param is_on_thread Function to return true if called from the same thread as
   *                     the scheduler. This function must be thread-safe.
   * @param can_deliver_notifications Function to return true if the scheduler can
   *                                  support `notify()`. This function does not
   *                                  need to be thread-safe.
   * @param set_notify_callback Function to accept a callback that will be invoked
   *                            by `notify()` on the scheduler's event loop. This
   *                            function does not need to be thread-safe.
   */
  RLM_API realm_scheduler_t*
  realm_scheduler_new(void* userdata, realm_free_userdata_func_t, realm_scheduler_notify_func_t notify,
                      realm_scheduler_is_on_thread_func_t is_on_thread, realm_scheduler_is_same_as_func_t is_same_as,
                      realm_scheduler_can_deliver_notifications_func_t can_deliver_notifications,
                      realm_scheduler_set_notify_callback_func_t set_notify_callback);
  
  /**
   * Create an instance of the default scheduler for the current platform,
   * normally confined to the calling thread.
   */
  RLM_API realm_scheduler_t* realm_scheduler_make_default(void);
  
  /**
   * Get the scheduler used by frozen realms. This scheduler does not support
   * notifications, and does not perform any thread checking.
   *
   * This function is thread-safe, and cannot fail.
   */
  RLM_API const realm_scheduler_t* realm_scheduler_get_frozen(void);
  
  /**
   * Returns true if there is a default scheduler implementation for the current
   * platform, or one has been set with `realm_scheduler_set_default_factory()`.
   *
   * If there is no default factory, and no scheduler is provided in the config,
   * `realm_open()` will fail. Note that `realm_scheduler_get_frozen()` always
   * returns a valid scheduler.
   *
   * This function is thread-safe, and cannot fail.
   */
  RLM_API bool realm_scheduler_has_default_factory(void);
  
  /**
   * For platforms with no default scheduler implementation, register a factory
   * function which can produce custom schedulers. If there is a platform-specific
   * scheduler, this function will fail. If a custom scheduler is desired for
   * platforms that already have a default scheduler implementation, the caller
   * must call `realm_open()` with a config that indicates the desired scheduler.
   *
   * The provided callback may produce a scheduler by calling
   * `realm_scheduler_new()`.
   *
   * This function is thread-safe, but should generally only be called once.
   */
  RLM_API bool realm_scheduler_set_default_factory(void* userdata, realm_free_userdata_func_t,
                                                   realm_scheduler_default_factory_func_t);
  
  /**
   * Trigger a call to the registered notifier callback on the scheduler's event loop.
   *
   * This function is thread-safe.
   */
  RLM_API void realm_scheduler_notify(realm_scheduler_t*);
  
  /**
   * Returns true if the caller is currently running on the scheduler's thread.
   *
   * This function is thread-safe.
   */
  RLM_API bool realm_scheduler_is_on_thread(const realm_scheduler_t*);
  
  /**
   * Returns true if the scheduler is able to deliver notifications.
   *
   * A false return value may indicate that notifications are not applicable for
   * the scheduler, not implementable, or a temporary inability to deliver
   * notifications.
   *
   * This function is not thread-safe.
   */
  RLM_API bool realm_scheduler_can_deliver_notifications(const realm_scheduler_t*);
  
  /**
   * Set the callback that will be invoked by `realm_scheduler_notify()`.
   *
   * This function is not thread-safe.
   */
  RLM_API bool realm_scheduler_set_notify_callback(realm_scheduler_t*, void* userdata, realm_free_userdata_func_t,
                                                   realm_scheduler_notify_func_t);
  
  
  /**
   * Open a Realm file.
   *
   * @param config Realm configuration. If the Realm is already opened on another
   *               thread, validate that the given configuration is compatible
   *               with the existing one.
   * @return If successful, the Realm object. Otherwise, NULL.
   */
  RLM_API realm_t* realm_open(const realm_config_t* config);
  
  /**
   * Create a `realm_t` object from a thread-safe reference to the same realm.
   *
   * @param tsr Thread-safe reference object created by calling
   *            `realm_get_thread_safe_reference()` with a `realm_t` instance.
   * @param scheduler The scheduler to use for the new `realm_t` instance. May be
   *                  NULL, in which case the default scheduler for the current
   *                  thread is used.
   * @return A non-null pointer if no error occurred.
   */
  RLM_API realm_t* realm_from_thread_safe_reference(realm_thread_safe_reference_t* tsr, realm_scheduler_t* scheduler);
  
  /**
   * Create a `realm_t*` from a `std::shared_ptr<Realm>*`.
   *
   * This is intended as a migration path for users of the C++ Object Store API.
   *
   * Call `realm_release()` on the returned `realm_t*` to decrement the refcount
   * on the inner `std::shared_ptr<Realm>`.
   *
   * @param pshared_ptr A pointer to an instance of `std::shared_ptr<Realm>`.
   * @param n Must be equal to `sizeof(std::shared_ptr<Realm>)`.
   * @return A `realm_t*` representing the same Realm object as the passed
   *         `std::shared_ptr<Realm>`.
   */
  RLM_API realm_t* _realm_from_native_ptr(const void* pshared_ptr, size_t n);
  
  /**
   * Get a `std::shared_ptr<Realm>` from a `realm_t*`.
   *
   * This is intended as a migration path for users of the C++ Object Store API.
   *
   * @param pshared_ptr A pointer to an instance of `std::shared_ptr<Realm>`.
   * @param n Must be equal to `sizeof(std::shared_ptr<Realm>)`.
   */
  RLM_API void _realm_get_native_ptr(const realm_t*, void* pshared_ptr, size_t n);
  
  /**
   * Forcibly close a Realm file.
   *
   * Note that this invalidates all Realm instances for the same path.
   *
   * The Realm will be automatically closed when the last reference is released,
   * including references to objects within the Realm.
   *
   * @return True if no exception occurred.
   */
  RLM_API bool realm_close(realm_t*);
  
  /**
   * True if the Realm file is closed.
   *
   * This function cannot fail.
   */
  RLM_API bool realm_is_closed(realm_t*);
  
  /**
   * Begin a read transaction for the Realm file.
   *
   * @return True if no exception occurred.
   */
  RLM_API bool realm_begin_read(realm_t*);
  
  /**
   * Begin a write transaction for the Realm file.
   *
   * @return True if no exception occurred.
   */
  RLM_API bool realm_begin_write(realm_t*);
  
  /**
   * Return true if the realm is in a write transaction.
   *
   * This function cannot fail.
   */
  RLM_API bool realm_is_writable(const realm_t*);
  
  /**
   * Commit a write transaction.
   *
   * @return True if the commit succeeded and no exceptions were thrown.
   */
  RLM_API bool realm_commit(realm_t*);
  
  /**
   * Roll back a write transaction.
   *
   * @return True if the rollback succeeded and no exceptions were thrown.
   */
  RLM_API bool realm_rollback(realm_t*);
  
  /**
   * Add a callback that will be invoked every time the view of this file is updated.
   *
   * This callback is guaranteed to be invoked before any object or collection change
   * notifications for this realm are delivered.
   *
   * @return a registration token used to remove the callback.
   */
  RLM_API uint64_t realm_add_realm_changed_callback(realm_t*, realm_on_realm_change_func_t, void* userdata,
                                                    realm_free_userdata_func_t);
  
  /**
   * Remove a realm changed callback that was previously registered with the token.
   */
  RLM_API void realm_remove_realm_changed_callback(realm_t*, uint64_t token);
  
  /**
   * Refresh the view of the realm file.
   *
   * If another process or thread has made changes to the realm file, this causes
   * those changes to become visible in this realm instance.
   *
   * This calls `advance_read()` at the Core layer.
   *
   * @return True if the realm was successfully refreshed and no exceptions were
   *         thrown.
   */
  RLM_API bool realm_refresh(realm_t*);
  
  /**
   * Produce a frozen view of this realm.
   *
   * @return A non-NULL realm instance representing the frozen state.
   */
  RLM_API realm_t* realm_freeze(const realm_t*);
  
  /**
   * Vacuum the free space from the realm file, reducing its file size.
   *
   * @return True if compaction was successful and no exceptions were thrown.
   */
  RLM_API bool realm_compact(realm_t*, bool* did_compact);
  
  /**
   * Create a new schema from classes and their properties.
   *
   * Note: This function does not validate the schema.
   *
   * Note: `realm_class_key_t` and `realm_property_key_t` values inside
   *       `realm_class_info_t` and `realm_property_info_t` are unused when
   *       defining the schema. Call `realm_get_schema()` to obtain the values for
   *       these fields in an open realm.
   *
   * @return True if allocation of the schema structure succeeded.
   */
  RLM_API realm_schema_t* realm_schema_new(const realm_class_info_t* classes, size_t num_classes,
                                           const realm_property_info_t** class_properties);
  
  /**
   * Get the schema for this realm.
   *
   * Note: The returned value is allocated by this function, so `realm_release()`
   *       must be called on it.
   */
  RLM_API realm_schema_t* realm_get_schema(const realm_t*);
  
  /**
   * Update the schema of an open realm.
   *
   * This is equivalent to calling `realm_update_schema_advanced(realm, schema, 0,
   * NULL, NULL, NULL, NULL, false)`.
   */
  RLM_API bool realm_update_schema(realm_t* realm, const realm_schema_t* schema);
  
  /**
   * Update the schema of an open realm, with options to customize certain steps
   * of the process.
   *
   * @param realm The realm for which the schema should be updated.
   * @param schema The new schema for the realm. If the schema is the same the
   *               existing schema, this function does nothing.
   * @param version The version of the new schema.
   * @param migration_func Callback to perform the migration. Has no effect if the
   *                       Realm is opened with `RLM_SCHEMA_MODE_ADDITIVE`.
   * @param migration_func_userdata Userdata pointer to pass to `migration_func`.
   * @param data_init_func Callback to perform initialization of the data in the
   *                       Realm if it is opened for the first time (i.e., it has
   *                       no previous schema version).
   * @param data_init_func_userdata Userdata pointer to pass to `data_init_func`.
   * @param is_in_transaction Pass true if the realm is already in a write
   *                          transaction. Otherwise, if the migration requires a
   *                          write transaction, this function will perform the
   *                          migration in its own write transaction.
   */
  RLM_API bool realm_update_schema_advanced(realm_t* realm, const realm_schema_t* schema, uint64_t version,
                                            realm_migration_func_t migration_func, void* migration_func_userdata,
                                            realm_data_initialization_func_t data_init_func,
                                            void* data_init_func_userdata, bool is_in_transaction);
  
  /**
   * Get the `realm::Schema*` pointer for this realm.
   *
   * This is intended as a migration path for users of the C++ Object Store API.
   *
   * The returned value is owned by the `realm_t` instance, and must not be freed.
   */
  RLM_API const void* _realm_get_schema_native(const realm_t*);
  
  /**
   * Add a callback that will be invoked every time the schema of this realm is changed.
   *
   * @return a registration token used to remove the callback.
   */
  RLM_API uint64_t realm_add_schema_changed_callback(realm_t*, realm_on_schema_change_func_t, void* userdata,
                                                     realm_free_userdata_func_t);
  
  /**
   * Remove a schema changed callback that was previously registered with the token.
   */
  RLM_API void realm_remove_schema_changed_callback(realm_t*, uint64_t token);
  
  /**
   * Validate the schema.
   *
   *  @param validation_mode A bitwise combination of values from the
   *                         enum realm_schema_validation_mode.
   *
   * @return True if the schema passed validation. If validation failed,
   *         `realm_get_last_error()` will produce an error describing the
   *         validation failure.
   */
  RLM_API bool realm_schema_validate(const realm_schema_t*, uint64_t validation_mode);
  
  /**
   * Return the number of classes in the Realm's schema.
   *
   * This cannot fail.
   */
  RLM_API size_t realm_get_num_classes(const realm_t*);
  
  /**
   * Get the table keys for classes in the schema.
   *
   * @param out_keys An array that will contain the keys of each class in the
   *                 schema. May be NULL, in which case `out_n` can be used to
   *                 determine the number of classes in the schema.
   * @param max The maximum number of keys to write to `out_keys`.
   * @param out_n The actual number of classes. May be NULL.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_get_class_keys(const realm_t*, realm_class_key_t* out_keys, size_t max, size_t* out_n);
  
  /**
   * Find a by the name of @a name.
   *
   * @param name The name of the class.
   * @param out_found Set to true if the class was found and no error occurred.
   *                  Otherwise, false. May not be NULL.
   * @param out_class_info A pointer to a `realm_class_info_t` that will be
   *                       populated with information about the class. May be
   *                       NULL.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_find_class(const realm_t*, const char* name, bool* out_found, realm_class_info_t* out_class_info);
  
  /**
   * Get the class with @a key from the schema.
   *
   * Passing an invalid @a key for this schema is considered an error.
   *
   * @param key The key of the class, as discovered by `realm_get_class_keys()`.
   * @param out_class_info A pointer to a `realm_class_info_t` that will be
   *                       populated with the information of the class. May be
   *                       NULL, though that's kind of pointless.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_get_class(const realm_t*, realm_class_key_t key, realm_class_info_t* out_class_info);
  
  /**
   * Get the list of properties for the class with this @a key.
   *
   * @param out_properties A pointer to an array of `realm_property_info_t`, which
   *                       will be populated with the information about the
   *                       properties. To see all properties, the length of the
   *                       array should be at least the number of properties in
   *                       the class, as reported in the sum of persisted and
   *                       computed properties for the class. May be NULL, in
   *                       which case this function can be used to discover the
   *                       number of properties in the class.
   * @param max The maximum number of entries to write to `out_properties`.
   * @param out_n The actual number of properties written to `out_properties`.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_get_class_properties(const realm_t*, realm_class_key_t key, realm_property_info_t* out_properties,
                                          size_t max, size_t* out_n);
  
  /**
   * Get the property keys for the class with this @a key.
   *
   * @param key The class key.
   * @param out_col_keys An array of property keys. May be NULL, in which case
   *                     this function can be used to discover the number of
   *                     properties for this class.
   * @param max The maximum number of keys to write to `out_col_keys`. Ignored if
   *            `out_col_keys == NULL`.
   * @param out_n The actual number of properties written to `out_col_keys` (if
   *              non-NULL), or number of properties in the class.
   **/
  RLM_API bool realm_get_property_keys(const realm_t*, realm_class_key_t key, realm_property_key_t* out_col_keys,
                                       size_t max, size_t* out_n);
  
  
  /**
   * Find a property by its column key.
   *
   * It is an error to pass a property @a key that is not present in this class.
   *
   * @param class_key The key of the class.
   * @param key The column key for the property.
   * @param out_property_info A pointer to a `realm_property_info_t` that will be
   *                          populated with information about the property.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_get_property(const realm_t*, realm_class_key_t class_key, realm_property_key_t key,
                                  realm_property_info_t* out_property_info);
  
  /**
   * Find a property by the internal (non-public) name of @a name.
   *
   * @param class_key The table key for the class.
   * @param name The name of the property.
   * @param out_found Will be set to true if the property was found. May not be
   *                  NULL.
   * @param out_property_info A pointer to a `realm_property_info_t` that will be
   *                          populated with information about the property. May
   *                          be NULL.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_find_property(const realm_t*, realm_class_key_t class_key, const char* name, bool* out_found,
                                   realm_property_info_t* out_property_info);
  
  /**
   * Find a property with the public name of @a name.
   *
   * @param class_key The table key for the class.
   * @param public_name The public name of the property.
   * @param out_found Will be set to true if the property was found. May not be
   *                  NULL.
   * @param out_property_info A pointer to a `realm_property_info_t` that will be
   *                          populated with information about the property. May
   *                          be NULL.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_find_property_by_public_name(const realm_t*, realm_class_key_t class_key, const char* public_name,
                                                  bool* out_found, realm_property_info_t* out_property_info);
  
  /**
   * Find the primary key property for a class, if it has one.
   *
   * @param class_key The table key for this class.
   * @param out_found Will be set to true if the property was found. May not be
   *                  NULL.
   * @param out_property_info A property to a `realm_property_info_t` that will be
   *                          populated with information about the property, if it
   *                          was found. May be NULL.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_find_primary_key_property(const realm_t*, realm_class_key_t class_key, bool* out_found,
                                               realm_property_info_t* out_property_info);
  
  /**
   * Get the number of objects in a table (class).
   *
   * @param out_count A pointer to a `size_t` that will contain the number of
   *                  objects, if successful.
   * @return True if the table key was valid for this realm.
   */
  RLM_API bool realm_get_num_objects(const realm_t*, realm_class_key_t, size_t* out_count);
  
  /**
   * Get the number of versions found in the Realm file.
   *
   * @param out_versions_count A pointer to a `size_t` that will contain the number of
   *                           versions, if successful.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_get_num_versions(const realm_t*, uint64_t* out_versions_count);
  
  /**
   * Get an object with a particular object key.
   *
   * @param class_key The class key.
   * @param obj_key The key to the object. Passing a non-existent key is
   *                considered an error.
   * @return A non-NULL pointer if no exception occurred.
   */
  RLM_API realm_object_t* realm_get_object(const realm_t*, realm_class_key_t class_key, realm_object_key_t obj_key);
  
  /**
   * Find an object with a particular primary key value.
   *
   * @param out_found A pointer to a boolean that will be set to true or false if
   *                  no error occurred.
   * @return A non-NULL pointer if the object was found and no exception occurred.
   */
  RLM_API realm_object_t* realm_object_find_with_primary_key(const realm_t*, realm_class_key_t, realm_value_t pk,
                                                             bool* out_found);
  
  /**
   * Find all objects in class.
   *
   * Note: This is faster than running a query matching all objects (such as
   *       "TRUEPREDICATE").
   *
   * @return A non-NULL pointer if no exception was thrown.
   */
  RLM_API realm_results_t* realm_object_find_all(const realm_t*, realm_class_key_t);
  
  /**
   * Create an object in a class without a primary key.
   *
   * @return A non-NULL pointer if the object was created successfully.
   */
  RLM_API realm_object_t* realm_object_create(realm_t*, realm_class_key_t);
  
  /**
   * Create an object in a class with a primary key. Will not succeed if an
   * object with the given primary key value already exists.
   *
   * @return A non-NULL pointer if the object was created successfully.
   */
  RLM_API realm_object_t* realm_object_create_with_primary_key(realm_t*, realm_class_key_t, realm_value_t pk);
  
  /**
   * Create an object in a class with a primary key. If an object with the given
   * primary key value already exists, that object will be returned.
   *
   * @return A non-NULL pointer if the object was found/created successfully.
   */
  RLM_API realm_object_t* realm_object_get_or_create_with_primary_key(realm_t*, realm_class_key_t, realm_value_t pk,
                                                                      bool* did_create);
  
  /**
   * Delete a realm object.
   *
   * Note: This does not call `realm_release()` on the `realm_object_t` instance.
   *
   * @return True if no exception occurred.
   */
  RLM_API bool realm_object_delete(realm_object_t*);
  
  /**
   * Resolve the Realm object in the provided Realm.
   *
   * This is equivalent to producing a thread-safe reference and resolving it in the target realm.
   *
   * If the object can be resolved in the target realm, '*resolved' points to the new object
   * If the object cannot be resolved in the target realm, '*resolved' will be null.
   * @return True if no exception occurred (except exceptions that may normally occur if resolution fails)
   */
  RLM_API bool realm_object_resolve_in(const realm_object_t* live_object, const realm_t* target_realm,
                                       realm_object_t** resolved);
  
  
  RLM_API realm_object_t* _realm_object_from_native_copy(const void* pobj, size_t n);
  RLM_API realm_object_t* _realm_object_from_native_move(void* pobj, size_t n);
  RLM_API const void* _realm_object_get_native_ptr(realm_object_t*);
  
  /**
   * True if this object still exists in the realm.
   *
   * This function cannot fail.
   */
  RLM_API bool realm_object_is_valid(const realm_object_t*);
  
  /**
   * Get the key for this object.
   *
   * This function cannot fail.
   */
  RLM_API realm_object_key_t realm_object_get_key(const realm_object_t* object);
  
  /**
   * Get the table for this object.
   *
   * This function cannot fail.
   */
  RLM_API realm_class_key_t realm_object_get_table(const realm_object_t* object);
  
  /**
   * Get a `realm_link_t` representing a link to @a object.
   *
   * This function cannot fail.
   */
  RLM_API realm_link_t realm_object_as_link(const realm_object_t* object);
  
  /**
   * Subscribe to notifications for this object.
   *
   * @return A non-null pointer if no exception occurred.
   */
  RLM_API realm_notification_token_t* realm_object_add_notification_callback(realm_object_t*, void* userdata,
                                                                             realm_free_userdata_func_t free,
                                                                             realm_on_object_change_func_t on_change,
                                                                             realm_callback_error_func_t on_error,
                                                                             realm_scheduler_t*);
  
  /**
   * Get an object from a thread-safe reference, potentially originating in a
   * different `realm_t` instance
   */
  RLM_API realm_object_t* realm_object_from_thread_safe_reference(const realm_t*, realm_thread_safe_reference_t*);
  
  /**
   * Get the value for a property.
   *
   * @return True if no exception occurred.
   */
  RLM_API bool realm_get_value(const realm_object_t*, realm_property_key_t, realm_value_t* out_value);
  
  /**
   * Get the values for several properties.
   *
   * This is provided as an alternative to calling `realm_get_value()` multiple
   * times in a row, which is particularly useful for language runtimes where
   * crossing the native bridge is comparatively expensive. In addition, it
   * eliminates some parameter validation that would otherwise be repeated for
   * each call.
   *
   * Example use cases:
   *
   *  - Extracting all properties of an object for serialization.
   *  - Converting an object to some in-memory representation.
   *
   * @param num_values The number of elements in @a properties and @a out_values.
   * @param properties The keys for the properties to fetch. May not be NULL.
   * @param out_values Where to write the property values. If an error occurs,
   *                   this array may only be partially initialized. May not be
   *                   NULL.
   * @return True if no exception occurs.
   */
  RLM_API bool realm_get_values(const realm_object_t*, size_t num_values, const realm_property_key_t* properties,
                                realm_value_t* out_values);
  
  /**
   * Set the value for a property.
   *
   * @param new_value The new value for the property.
   * @param is_default True if this property is being set as part of setting the
   *                   default values for a new object. This has no effect in
   *                   non-sync'ed realms.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_set_value(realm_object_t*, realm_property_key_t, realm_value_t new_value, bool is_default);
  
  /**
   * Set the values for several properties.
   *
   * This is provided as an alternative to calling `realm_get_value()` multiple
   * times in a row, which is particularly useful for language runtimes where
   * crossing the native bridge is comparatively expensive. In addition, it
   * eliminates some parameter validation that would otherwise be repeated for
   * each call.
   *
   * Example use cases:
   *
   *  - Initializing a new object with default values.
   *  - Deserializing some in-memory structure into a realm object.
   *
   * This operation is "atomic"; if an exception occurs due to invalid input (such
   * as type mismatch, nullability mismatch, etc.), the object will remain
   * unmodified.
   *
   * @param num_values The number of elements in @a properties and @a values.
   * @param properties The keys of the properties to set. May not be NULL.
   * @param values The values to assign to the properties. May not be NULL.
   * @param is_default True if the properties are being set as part of setting
   *                   default values for a new object. This has no effect in
   *                   non-sync'ed realms.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_set_values(realm_object_t*, size_t num_values, const realm_property_key_t* properties,
                                const realm_value_t* values, bool is_default);
  
  /**
   * Get a list instance for the property of an object.
   *
   * Note: It is up to the caller to call `realm_release()` on the returned list.
   *
   * @return A non-null pointer if no exception occurred.
   */
  RLM_API realm_list_t* realm_get_list(realm_object_t*, realm_property_key_t);
  
  /**
   * Create a `realm_list_t` from a pointer to a `realm::List`, copy-constructing
   * the internal representation.
   *
   * @param plist A pointer to an instance of `realm::List`.
   * @param n Must be equal to `sizeof(realm::List)`.
   * @return A non-null pointer if no exception occurred.
   */
  RLM_API realm_list_t* _realm_list_from_native_copy(const void* plist, size_t n);
  
  /**
   * Create a `realm_list_t` from a pointer to a `realm::List`, move-constructing
   * the internal representation.
   *
   * @param plist A pointer to an instance of `realm::List`.
   * @param n Must be equal to `sizeof(realm::List)`.
   * @return A non-null pointer if no exception occurred.
   */
  RLM_API realm_list_t* _realm_list_from_native_move(void* plist, size_t n);
  
  /**
   * Resolve the list in the context of a given Realm instance.
   *
   * This is equivalent to producing a thread-safe reference and resolving it in the frozen realm.
   *
   * If resolution is possible, a valid resolved object is produced at '*resolved*'.
   * If resolution is not possible, but no error occurs, '*resolved' is set to NULL
   *
   * @return true if no error occurred.
   */
  RLM_API bool realm_list_resolve_in(const realm_list_t* list, const realm_t* target_realm, realm_list_t** resolved);
  
  /**
   * Check if a list is valid.
   *
   * @return True if the list is valid.
   */
  RLM_API bool realm_list_is_valid(const realm_list_t*);
  
  /**
   * Get the size of a list, in number of elements.
   *
   * This function may fail if the object owning the list has been deleted.
   *
   * @param out_size Where to put the list size. May be NULL.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_list_size(const realm_list_t*, size_t* out_size);
  
  /**
   * Get the property that this list came from.
   *
   * @return True if no exception occurred.
   */
  RLM_API bool realm_list_get_property(const realm_list_t*, realm_property_info_t* out_property_info);
  
  /**
   * Get the value at @a index.
   *
   * @param out_value The resulting value, if no error occurred. May be NULL,
   *                  though nonsensical.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_list_get(const realm_list_t*, size_t index, realm_value_t* out_value);
  
  /**
   * Set the value at @a index.
   *
   * @param value The value to set.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_list_set(realm_list_t*, size_t index, realm_value_t value);
  
  /**
   * Insert @a value at @a index.
   *
   * @param value The value to insert.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_list_insert(realm_list_t*, size_t index, realm_value_t value);
  
  /**
   * Erase the element at @a index.
   *
   * @return True if no exception occurred.
   */
  RLM_API bool realm_list_erase(realm_list_t*, size_t index);
  
  /**
   * Clear a list, removing all elements in the list. In a list of links, this
   * does *NOT* delete the target objects.
   *
   * @return True if no exception occurred.
   */
  RLM_API bool realm_list_clear(realm_list_t*);
  
  /**
   * In a list of objects, delete all objects in the list and clear the list. In a
   * list of values, clear the list.
   *
   * @return True if no exception occurred.
   */
  RLM_API bool realm_list_remove_all(realm_list_t*);
  
  /**
   * Replace the contents of a list with values.
   *
   * This is equivalent to calling `realm_list_clear()`, and then
   * `realm_list_insert()` repeatedly.
   *
   * @return True if no exception occurred.
   */
  RLM_API bool realm_list_assign(realm_list_t*, const realm_value_t* values, size_t num_values);
  
  /**
   * Subscribe to notifications for this object.
   *
   * @return A non-null pointer if no exception occurred.
   */
  RLM_API realm_notification_token_t* realm_list_add_notification_callback(realm_list_t*, void* userdata,
                                                                           realm_free_userdata_func_t free,
                                                                           realm_on_collection_change_func_t on_change,
                                                                           realm_callback_error_func_t on_error,
                                                                           realm_scheduler_t*);
  
  /**
   * Get an list from a thread-safe reference, potentially originating in a
   * different `realm_t` instance
   */
  RLM_API realm_list_t* realm_list_from_thread_safe_reference(const realm_t*, realm_thread_safe_reference_t*);
  
  /**
   * True if an object notification indicates that the object was deleted.
   *
   * This function cannot fail.
   */
  RLM_API bool realm_object_changes_is_deleted(const realm_object_changes_t*);
  
  /**
   * Get the number of properties that were modified in an object notification.
   *
   * This function cannot fail.
   */
  RLM_API size_t realm_object_changes_get_num_modified_properties(const realm_object_changes_t*);
  
  /**
   * Get the column keys for the properties that were modified in an object
   * notification.
   *
   * This function cannot fail.
   *
   * @param out_modified Where the column keys should be written. May be NULL.
   * @param max The maximum number of column keys to write.
   * @return The number of column keys written to @a out_modified, or the number
   *         of modified properties if @a out_modified is NULL.
   */
  RLM_API size_t realm_object_changes_get_modified_properties(const realm_object_changes_t*,
                                                              realm_property_key_t* out_modified, size_t max);
  
  /**
   * Get the number of various types of changes in a collection notification.
   *
   * @param out_num_deletions The number of deletions. May be NULL.
   * @param out_num_insertions The number of insertions. May be NULL.
   * @param out_num_modifications The number of modifications. May be NULL.
   * @param out_num_moves The number of moved elements. May be NULL.
   */
  RLM_API void realm_collection_changes_get_num_changes(const realm_collection_changes_t*, size_t* out_num_deletions,
                                                        size_t* out_num_insertions, size_t* out_num_modifications,
                                                        size_t* out_num_moves);
  
  /**
   * Get the number of various types of changes in a collection notification,
   * suitable for acquiring the change indices as ranges, which is much more
   * compact in memory than getting the individual indices when multiple adjacent
   * elements have been modified.
   *
   * @param out_num_deletion_ranges The number of deleted ranges. May be NULL.
   * @param out_num_insertion_ranges The number of inserted ranges. May be NULL.
   * @param out_num_modification_ranges The number of modified ranges. May be
   *                                    NULL.
   * @param out_num_moves The number of moved elements. May be NULL.
   */
  RLM_API void realm_collection_changes_get_num_ranges(const realm_collection_changes_t*,
                                                       size_t* out_num_deletion_ranges,
                                                       size_t* out_num_insertion_ranges,
                                                       size_t* out_num_modification_ranges, size_t* out_num_moves);
  
  typedef struct realm_collection_move {
      size_t from;
      size_t to;
  } realm_collection_move_t;
  
  typedef struct realm_index_range {
      size_t from;
      size_t to;
  } realm_index_range_t;
  
  /**
   * Get the indices of changes in a collection notification.
   *
   * Note: For moves, every `from` index will also be present among deletions, and
   *       every `to` index will also be present among insertions.
   *
   * This function cannot fail.
   *
   * @param out_deletion_indices Where to put the indices of deleted elements
   *                             (*before* the deletion happened). May be NULL.
   * @param max_deletion_indices The max number of indices to write to @a
   *                             out_deletion_indices.
   * @param out_insertion_indices Where the put the indices of inserted elements
   *                              (*after* the insertion happened). May be NULL.
   * @param max_insertion_indices The max number of indices to write to @a
   *                              out_insertion_indices.
   * @param out_modification_indices Where to put the indices of modified elements
   *                                 (*before* any insertions or deletions of
   *                                 other elements). May be NULL.
   * @param max_modification_indices The max number of indices to write to @a
   *                                 out_modification_indices.
   * @param out_modification_indices_after Where to put the indices of modified
   *                                       elements (*after* any insertions or
   *                                       deletions of other elements). May be
   *                                       NULL.
   * @param max_modification_indices_after The max number of indices to write to
   *                                       @a out_modification_indices_after.
   * @param out_moves Where to put the pairs of indices of moved elements. May be
   *                  NULL.
   * @param max_moves The max number of pairs to write to @a out_moves.
   */
  RLM_API void realm_collection_changes_get_changes(const realm_collection_changes_t*, size_t* out_deletion_indices,
                                                    size_t max_deletion_indices, size_t* out_insertion_indices,
                                                    size_t max_insertion_indices, size_t* out_modification_indices,
                                                    size_t max_modification_indices,
                                                    size_t* out_modification_indices_after,
                                                    size_t max_modification_indices_after,
                                                    realm_collection_move_t* out_moves, size_t max_moves);
  
  RLM_API void realm_collection_changes_get_ranges(
      const realm_collection_changes_t*, realm_index_range_t* out_deletion_ranges, size_t max_deletion_ranges,
      realm_index_range_t* out_insertion_ranges, size_t max_insertion_ranges,
      realm_index_range_t* out_modification_ranges, size_t max_modification_ranges,
      realm_index_range_t* out_modification_ranges_after, size_t max_modification_ranges_after,
      realm_collection_move_t* out_moves, size_t max_moves);
  
  RLM_API realm_set_t* _realm_set_from_native_copy(const void* pset, size_t n);
  RLM_API realm_set_t* _realm_set_from_native_move(void* pset, size_t n);
  RLM_API realm_set_t* realm_get_set(const realm_object_t*, realm_property_key_t);
  RLM_API size_t realm_set_size(const realm_set_t*);
  RLM_API bool realm_set_get(const realm_set_t*, size_t index, realm_value_t* out_value);
  RLM_API bool realm_set_find(const realm_set_t*, realm_value_t value, size_t* out_index);
  RLM_API bool realm_set_insert(realm_set_t*, realm_value_t value, size_t out_index);
  RLM_API bool realm_set_erase(realm_set_t*, realm_value_t value, bool* out_erased);
  RLM_API bool realm_set_clear(realm_set_t*);
  RLM_API bool realm_set_assign(realm_set_t*, realm_value_t values, size_t num_values);
  RLM_API realm_notification_token_t* realm_set_add_notification_callback(realm_object_t*, void* userdata,
                                                                          realm_free_userdata_func_t free,
                                                                          realm_on_collection_change_func_t on_change,
                                                                          realm_callback_error_func_t on_error,
                                                                          realm_scheduler_t*);
  
  
  RLM_API realm_dictionary_t* _realm_dictionary_from_native_copy(const void* pdict, size_t n);
  RLM_API realm_dictionary_t* _realm_dictionary_from_native_move(void* pdict, size_t n);
  RLM_API realm_dictionary_t* realm_get_dictionary(const realm_object_t*, realm_property_key_t);
  RLM_API size_t realm_dictionary_size(const realm_dictionary_t*);
  RLM_API bool realm_dictionary_get(const realm_dictionary_t*, realm_value_t key, realm_value_t* out_value,
                                    bool* out_found);
  RLM_API bool realm_dictionary_insert(realm_dictionary_t*, realm_value_t key, realm_value_t value, bool* out_inserted,
                                       size_t* out_index);
  RLM_API bool realm_dictionary_erase(realm_dictionary_t*, realm_value_t key, bool* out_erased);
  RLM_API bool realm_dictionary_clear(realm_dictionary_t*);
  typedef realm_value_t realm_key_value_pair_t[2];
  RLM_API bool realm_dictionary_assign(realm_dictionary_t*, const realm_key_value_pair_t* pairs, size_t num_pairs);
  RLM_API realm_notification_token_t*
  realm_dictionary_add_notification_callback(realm_object_t*, void* userdata, realm_free_userdata_func_t free,
                                             realm_on_collection_change_func_t on_change,
                                             realm_callback_error_func_t on_error, realm_scheduler_t*);
  
  /**
   * Parse a query string and bind it to a table.
   *
   * If the query failed to parse, the parser error is available from
   * `realm_get_last_error()`.
   *
   * @param target_table The table on which to run this query.
   * @param query_string A zero-terminated string in the Realm Query Language,
   *                     optionally containing argument placeholders (`$0`, `$1`,
   *                     etc.).
   * @param num_args The number of arguments for this query.
   * @param args A pointer to a list of argument values.
   * @return A non-null pointer if the query was successfully parsed and no
   *         exception occurred.
   */
  RLM_API realm_query_t* realm_query_parse(const realm_t*, realm_class_key_t target_table, const char* query_string,
                                           size_t num_args, const realm_value_t* args);
  
  /**
   * Parse a query string and bind it to a list.
   *
   * If the query failed to parse, the parser error is available from
   * `realm_get_last_error()`.
   *
   * @param target_list The list on which to run this query.
   * @param query_string A string in the Realm Query Language, optionally
   *                     containing argument placeholders (`$0`, `$1`, etc.).
   * @param num_args The number of arguments for this query.
   * @param args A pointer to a list of argument values.
   * @return A non-null pointer if the query was successfully parsed and no
   *         exception occurred.
   */
  RLM_API realm_query_t* realm_query_parse_for_list(const realm_list_t* target_list, const char* query_string,
                                                    size_t num_args, const realm_value_t* args);
  
  /**
   * Parse a query string and bind it to another query result.
   *
   * If the query failed to parse, the parser error is available from
   * `realm_get_last_error()`.
   *
   * @param target_results The results on which to run this query.
   * @param query_string A zero-terminated string in the Realm Query Language,
   *                     optionally containing argument placeholders (`$0`, `$1`,
   *                     etc.).
   * @param num_args The number of arguments for this query.
   * @param args A pointer to a list of argument values.
   * @return A non-null pointer if the query was successfully parsed and no
   *         exception occurred.
   */
  RLM_API realm_query_t* realm_query_parse_for_results(const realm_results_t* target_results, const char* query_string,
                                                       size_t num_args, const realm_value_t* args);
  
  /**
   * Count the number of objects found by this query.
   */
  RLM_API bool realm_query_count(const realm_query_t*, size_t* out_count);
  
  /**
   * Return the first object matched by this query.
   *
   * Note: This function can only produce objects, not values. Use the
   *       `realm_results_t` returned by `realm_query_find_all()` to retrieve
   *       values from a list of primitive values.
   *
   * @param out_value Where to write the result, if any object matched the query.
   *                  May be NULL.
   * @param out_found Where to write whether the object was found. May be NULL.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_query_find_first(realm_query_t*, realm_value_t* out_value, bool* out_found);
  
  /**
   * Produce a results object for this query.
   *
   * Note: This does not actually run the query until the results are accessed in
   *       some way.
   *
   * @return A non-null pointer if no exception occurred.
   */
  RLM_API realm_results_t* realm_query_find_all(realm_query_t*);
  
  /**
   * Delete all objects matched by a query.
   */
  RLM_API bool realm_query_delete_all(const realm_query_t*);
  
  /**
   * Count the number of results.
   *
   * If the result is "live" (not a snapshot), this may rerun the query if things
   * have changed.
   *
   * @return True if no exception occurred.
   */
  RLM_API bool realm_results_count(realm_results_t*, size_t* out_count);
  
  /**
   * Get the matching element at @a index in the results.
   *
   * If the result is "live" (not a snapshot), this may rerun the query if things
   * have changed.
   *
   * Note: The bound returned by `realm_results_count()` for a non-snapshot result
   *       is not a reliable way to iterate over elements in the result, because
   *       the result will be live-updated if changes are made in each iteration
   *       that may change the number of query results or even change the
   *       ordering. In other words, this method should probably only be used with
   *       snapshot results.
   *
   * @return True if no exception occurred (including out-of-bounds).
   */
  RLM_API bool realm_results_get(realm_results_t*, size_t index, realm_value_t* out_value);
  
  /**
   * Get the matching object at @a index in the results.
   *
   * If the result is "live" (not a snapshot), this may rerun the query if things
   * have changed.
   *
   * Note: The bound returned by `realm_results_count()` for a non-snapshot result
   *       is not a reliable way to iterate over elements in the result, because
   *       the result will be live-updated if changes are made in each iteration
   *       that may change the number of query results or even change the
   *       ordering. In other words, this method should probably only be used with
   *       snapshot results.
   *
   * @return An instance of `realm_object_t` if no exception occurred.
   */
  RLM_API realm_object_t* realm_results_get_object(realm_results_t*, size_t index);
  
  /**
   * Delete all objects in the result.
   *
   * If the result if "live" (not a snapshot), this may rerun the query if things
   * have changed.
   *
   * @return True if no exception occurred.
   */
  RLM_API bool realm_results_delete_all(realm_results_t*);
  
  /**
   * Return a snapshot of the results that never automatically updates.
   *
   * The returned result is suitable for use with `realm_results_count()` +
   * `realm_results_get()`.
   */
  RLM_API realm_results_t* realm_results_snapshot(const realm_results_t*);
  
  /**
   * Map the Results into a live Realm instance.
   *
   * This is equivalent to producing a thread-safe reference and resolving it in the live realm.
   *
   * @return A live copy of the Results.
   */
  RLM_API realm_results_t* realm_results_resolve_in(realm_results_t* from_results, const realm_t* target_realm);
  
  /**
   * Compute the minimum value of a property in the results.
   *
   * @param out_min Where to write the result, if there were matching rows.
   * @param out_found Set to true if there are matching rows.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_results_min(realm_results_t*, realm_property_key_t, realm_value_t* out_min, bool* out_found);
  
  /**
   * Compute the maximum value of a property in the results.
   *
   * @param out_max Where to write the result, if there were matching rows.
   * @param out_found Set to true if there are matching rows.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_results_max(realm_results_t*, realm_property_key_t, realm_value_t* out_max, bool* out_found);
  
  /**
   * Compute the sum value of a property in the results.
   *
   * @param out_sum Where to write the result. Zero if no rows matched.
   * @param out_found Set to true if there are matching rows.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_results_sum(realm_results_t*, realm_property_key_t, realm_value_t* out_sum, bool* out_found);
  
  /**
   * Compute the average value of a property in the results.
   *
   * Note: For numeric columns, the average is always converted to double.
   *
   * @param out_average Where to write the result.
   * @param out_found Set to true if there are matching rows.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_results_average(realm_results_t*, realm_property_key_t, realm_value_t* out_average,
                                     bool* out_found);
  
  RLM_API realm_notification_token_t* realm_results_add_notification_callback(realm_results_t*, void* userdata,
                                                                              realm_free_userdata_func_t,
                                                                              realm_on_collection_change_func_t,
                                                                              realm_callback_error_func_t,
                                                                              realm_scheduler_t*);
  
  /**
   * Get an results object from a thread-safe reference, potentially originating
   * in a different `realm_t` instance
   */
  RLM_API realm_results_t* realm_results_from_thread_safe_reference(const realm_t*, realm_thread_safe_reference_t*);
  
  /* Logging */
  // equivalent to realm::util::Logger::Level in util/logger.hpp and must be kept in sync.
  typedef enum realm_log_level {
      RLM_LOG_LEVEL_ALL = 0,
      RLM_LOG_LEVEL_TRACE = 1,
      RLM_LOG_LEVEL_DEBUG = 2,
      RLM_LOG_LEVEL_DETAIL = 3,
      RLM_LOG_LEVEL_INFO = 4,
      RLM_LOG_LEVEL_WARNING = 5,
      RLM_LOG_LEVEL_ERROR = 6,
      RLM_LOG_LEVEL_FATAL = 7,
      RLM_LOG_LEVEL_OFF = 8,
  } realm_log_level_e;
  
  typedef void (*realm_log_func_t)(void* userdata, realm_log_level_e level, const char* message);
  
  /* HTTP transport */
  typedef enum realm_http_request_method {
      RLM_HTTP_REQUEST_METHOD_GET,
      RLM_HTTP_REQUEST_METHOD_POST,
      RLM_HTTP_REQUEST_METHOD_PATCH,
      RLM_HTTP_REQUEST_METHOD_PUT,
      RLM_HTTP_REQUEST_METHOD_DELETE,
  } realm_http_request_method_e;
  
  typedef struct realm_http_header {
      const char* name;
      const char* value;
  } realm_http_header_t;
  
  typedef struct realm_http_request {
      realm_http_request_method_e method;
      const char* url;
      uint64_t timeout_ms;
      const realm_http_header_t* headers;
      size_t num_headers;
      const char* body;
      size_t body_size;
  } realm_http_request_t;
  
  typedef struct realm_http_response {
      int status_code;
      int custom_status_code;
      const realm_http_header_t* headers;
      size_t num_headers;
      const char* body;
      size_t body_size;
  } realm_http_response_t;
  
  /**
   * Callback function used by Core to make a HTTP request.
   *
   * Complete the request by calling realm_http_transport_complete_request(),
   * passing in the request_context pointer here and the received response.
   * Network request are expected to be asynchronous and can be completed on any thread.
   *
   * @param userdata The userdata pointer passed to realm_http_transport_new().
   * @param request The request to send.
   * @param request_context Internal state pointer of Core, needed by realm_http_transport_complete_request().
   */
  typedef void (*realm_http_request_func_t)(void* userdata, const realm_http_request_t request, void* request_context);
  
  typedef struct realm_http_transport realm_http_transport_t;
  
  /**
   * Create a new HTTP transport with these callbacks implementing its functionality.
   */
  RLM_API realm_http_transport_t* realm_http_transport_new(realm_http_request_func_t, void* userdata,
                                                           realm_free_userdata_func_t);
  
  /**
   * Complete a HTTP request with the given response.
   *
   * @param request_context Internal state pointer passed by Core when invoking realm_http_request_func_t
   *                        to start the request.
   * @param response The server response to the HTTP request initiated by Core.
   */
  RLM_API void realm_http_transport_complete_request(void* request_context, const realm_http_response_t* response);
  
  /* App */
  typedef struct realm_app realm_app_t;
  typedef struct realm_app_credentials realm_app_credentials_t;
  typedef struct realm_user realm_user_t;
  
  typedef enum realm_user_state {
      RLM_USER_STATE_LOGGED_OUT,
      RLM_USER_STATE_LOGGED_IN,
      RLM_USER_STATE_REMOVED
  } realm_user_state_e;
  
  /**
   * Possible error categories the realm_app_error_t error code can fall in.
   */
  typedef enum realm_app_error_category {
      /**
       * Error category for HTTP-related errors. The error code value can be interpreted as a HTTP status code.
       */
      RLM_APP_ERROR_CATEGORY_HTTP,
      /**
       * JSON response parsing related errors. The error code is a member of realm_app_errno_json_e.
       */
      RLM_APP_ERROR_CATEGORY_JSON,
      /**
       * Client-side related errors. The error code is a member of realm_app_errno_client_e.
       */
      RLM_APP_ERROR_CATEGORY_CLIENT,
      /**
       * Errors reported by the backend. The error code is a member of realm_app_errno_service_e.
       */
      RLM_APP_ERROR_CATEGORY_SERVICE,
      /**
       * Custom error code was set in realm_http_response_t.custom_status_code.
       * The error code is the custom_status_code value.
       */
      RLM_APP_ERROR_CATEGORY_CUSTOM,
  } realm_app_error_category_e;
  
  typedef enum realm_app_errno_json {
      RLM_APP_ERR_JSON_BAD_TOKEN = 1,
      RLM_APP_ERR_JSON_MALFORMED_JSON = 2,
      RLM_APP_ERR_JSON_MISSING_JSON_KEY = 3,
      RLM_APP_ERR_JSON_BAD_BSON_PARSE = 4
  } realm_app_errno_json_e;
  
  typedef enum realm_app_errno_client {
      RLM_APP_ERR_CLIENT_USER_NOT_FOUND = 1,
      RLM_APP_ERR_CLIENT_USER_NOT_LOGGED_IN = 2,
      RLM_APP_ERR_CLIENT_APP_DEALLOCATED = 3
  } realm_app_errno_client_e;
  
  typedef enum realm_app_errno_service {
      RLM_APP_ERR_SERVICE_MISSING_AUTH_REQ = 1,
      RLM_APP_ERR_SERVICE_INVALID_SESSION = 2,
      RLM_APP_ERR_SERVICE_USER_APP_DOMAIN_MISMATCH = 3,
      RLM_APP_ERR_SERVICE_DOMAIN_NOT_ALLOWED = 4,
      RLM_APP_ERR_SERVICE_READ_SIZE_LIMIT_EXCEEDED = 5,
      RLM_APP_ERR_SERVICE_INVALID_PARAMETER = 6,
      RLM_APP_ERR_SERVICE_MISSING_PARAMETER = 7,
      RLM_APP_ERR_SERVICE_TWILIO_ERROR = 8,
      RLM_APP_ERR_SERVICE_GCM_ERROR = 9,
      RLM_APP_ERR_SERVICE_HTTP_ERROR = 10,
      RLM_APP_ERR_SERVICE_AWS_ERROR = 11,
      RLM_APP_ERR_SERVICE_MONGODB_ERROR = 12,
      RLM_APP_ERR_SERVICE_ARGUMENTS_NOT_ALLOWED = 13,
      RLM_APP_ERR_SERVICE_FUNCTION_EXECUTION_ERROR = 14,
      RLM_APP_ERR_SERVICE_NO_MATCHING_RULE_FOUND = 15,
      RLM_APP_ERR_SERVICE_INTERNAL_SERVER_ERROR = 16,
      RLM_APP_ERR_SERVICE_AUTH_PROVIDER_NOT_FOUND = 17,
      RLM_APP_ERR_SERVICE_AUTH_PROVIDER_ALREADY_EXISTS = 18,
      RLM_APP_ERR_SERVICE_SERVICE_NOT_FOUND = 19,
      RLM_APP_ERR_SERVICE_SERVICE_TYPE_NOT_FOUND = 20,
      RLM_APP_ERR_SERVICE_SERVICE_ALREADY_EXISTS = 21,
      RLM_APP_ERR_SERVICE_SERVICE_COMMAND_NOT_FOUND = 22,
      RLM_APP_ERR_SERVICE_VALUE_NOT_FOUND = 23,
      RLM_APP_ERR_SERVICE_VALUE_ALREADY_EXISTS = 24,
      RLM_APP_ERR_SERVICE_VALUE_DUPLICATE_NAME = 25,
      RLM_APP_ERR_SERVICE_FUNCTION_NOT_FOUND = 26,
      RLM_APP_ERR_SERVICE_FUNCTION_ALREADY_EXISTS = 27,
      RLM_APP_ERR_SERVICE_FUNCTION_DUPLICATE_NAME = 28,
      RLM_APP_ERR_SERVICE_FUNCTION_SYNTAX_ERROR = 29,
      RLM_APP_ERR_SERVICE_FUNCTION_INVALID = 30,
      RLM_APP_ERR_SERVICE_INCOMING_WEBHOOK_NOT_FOUND = 31,
      RLM_APP_ERR_SERVICE_INCOMING_WEBHOOK_ALREADY_EXISTS = 32,
      RLM_APP_ERR_SERVICE_INCOMING_WEBHOOK_DUPLICATE_NAME = 33,
      RLM_APP_ERR_SERVICE_RULE_NOT_FOUND = 34,
      RLM_APP_ERR_SERVICE_API_KEY_NOT_FOUND = 35,
      RLM_APP_ERR_SERVICE_RULE_ALREADY_EXISTS = 36,
      RLM_APP_ERR_SERVICE_RULE_DUPLICATE_NAME = 37,
      RLM_APP_ERR_SERVICE_AUTH_PROVIDER_DUPLICATE_NAME = 38,
      RLM_APP_ERR_SERVICE_RESTRICTED_HOST = 39,
      RLM_APP_ERR_SERVICE_API_KEY_ALREADY_EXISTS = 40,
      RLM_APP_ERR_SERVICE_INCOMING_WEBHOOK_AUTH_FAILED = 41,
      RLM_APP_ERR_SERVICE_EXECUTION_TIME_LIMIT_EXCEEDED = 42,
      RLM_APP_ERR_SERVICE_NOT_CALLABLE = 43,
      RLM_APP_ERR_SERVICE_USER_ALREADY_CONFIRMED = 44,
      RLM_APP_ERR_SERVICE_USER_NOT_FOUND = 45,
      RLM_APP_ERR_SERVICE_USER_DISABLED = 46,
      RLM_APP_ERR_SERVICE_AUTH_ERROR = 47,
      RLM_APP_ERR_SERVICE_BAD_REQUEST = 48,
      RLM_APP_ERR_SERVICE_ACCOUNT_NAME_IN_USE = 49,
      RLM_APP_ERR_SERVICE_INVALID_EMAIL_PASSWORD = 50,
  
      RLM_APP_ERR_SERVICE_UNKNOWN = -1,
      RLM_APP_ERR_SERVICE_NONE = 0
  } realm_app_errno_service_e;
  
  typedef enum realm_auth_provider {
      RLM_AUTH_PROVIDER_ANONYMOUS,
      RLM_AUTH_PROVIDER_FACEBOOK,
      RLM_AUTH_PROVIDER_GOOGLE,
      RLM_AUTH_PROVIDER_APPLE,
      RLM_AUTH_PROVIDER_CUSTOM,
      RLM_AUTH_PROVIDER_EMAIL_PASSWORD,
      RLM_AUTH_PROVIDER_FUNCTION,
      RLM_AUTH_PROVIDER_USER_API_KEY,
      RLM_AUTH_PROVIDER_SERVER_API_KEY,
  } realm_auth_provider_e;
  
  typedef struct realm_app_user_apikey {
      realm_object_id_t id;
      const char* key;
      const char* name;
      bool disabled;
  } realm_app_user_apikey_t;
  
  // This type should never be returned from a function.
  // It's only meant as an asynchronous callback argument.
  // Pointers to this struct and its pointer members are only valid inside the scope
  // of the callback they were passed to.
  typedef struct realm_app_error {
      realm_app_error_category_e error_category;
      int error_code;
  
      /**
       * The underlying HTTP status code returned by the server,
       * otherwise zero.
       */
      int http_status_code;
  
      const char* message;
  
      /**
       * A link to MongoDB Realm server logs related to the error,
       * or NULL if error response didn't contain log information.
       */
      const char* link_to_server_logs;
  } realm_app_error_t;
  
  /**
   * Generic completion callback for asynchronous Realm App operations.
   *
   * @param userdata The userdata pointer the asynchronous operation was started with.
   * @param error Pointer to an error object if the operation failed, otherwise null if it completed successfully.
   */
  typedef void (*realm_app_void_completion_func_t)(void* userdata, const realm_app_error_t* error);
  
  /**
   * Completion callback for asynchronous Realm App operations that yield a user object.
   *
   * @param userdata The userdata pointer the asynchronous operation was started with.
   * @param user User object produced by the operation, or null if it failed.
   *             The pointer is alive only for the duration of the callback,
   *             if you wish to use it further make a copy with realm_clone().
   * @param error Pointer to an error object if the operation failed, otherwise null if it completed successfully.
   */
  typedef void (*realm_app_user_completion_func_t)(void* userdata, realm_user_t* user, const realm_app_error_t* error);
  
  RLM_API realm_app_credentials_t* realm_app_credentials_new_anonymous(void) RLM_API_NOEXCEPT;
  RLM_API realm_app_credentials_t* realm_app_credentials_new_facebook(const char* access_token) RLM_API_NOEXCEPT;
  RLM_API realm_app_credentials_t* realm_app_credentials_new_google(const char* id_token) RLM_API_NOEXCEPT;
  RLM_API realm_app_credentials_t* realm_app_credentials_new_apple(const char* id_token) RLM_API_NOEXCEPT;
  RLM_API realm_app_credentials_t* realm_app_credentials_new_jwt(const char* jwt_token) RLM_API_NOEXCEPT;
  RLM_API realm_app_credentials_t* realm_app_credentials_new_email_password(const char* email,
                                                                            realm_string_t password) RLM_API_NOEXCEPT;
  RLM_API realm_app_credentials_t* realm_app_credentials_new_user_api_key(const char* api_key) RLM_API_NOEXCEPT;
  RLM_API realm_app_credentials_t* realm_app_credentials_new_server_api_key(const char* api_key) RLM_API_NOEXCEPT;
  
  /**
   * Create Custom Function authentication app credentials.
   *
   * @param serialized_ejson_payload The arguments array to invoke the function with,
   *                                 serialized as an Extended JSON string.
   * @return null, if an error occurred.
   */
  RLM_API realm_app_credentials_t* realm_app_credentials_new_function(const char* serialized_ejson_payload);
  
  RLM_API realm_auth_provider_e realm_auth_credentials_get_provider(realm_app_credentials_t*) RLM_API_NOEXCEPT;
  
  /**
   * Create a new app configuration.
   *
   * @param app_id The MongoDB Realm app id.
   * @param http_transport The HTTP transport used to make network calls.
   */
  RLM_API realm_app_config_t* realm_app_config_new(const char* app_id,
                                                   const realm_http_transport_t* http_transport) RLM_API_NOEXCEPT;
  
  RLM_API void realm_app_config_set_base_url(realm_app_config_t*, const char*) RLM_API_NOEXCEPT;
  RLM_API void realm_app_config_set_local_app_name(realm_app_config_t*, const char*) RLM_API_NOEXCEPT;
  RLM_API void realm_app_config_set_local_app_version(realm_app_config_t*, const char*) RLM_API_NOEXCEPT;
  RLM_API void realm_app_config_set_default_request_timeout(realm_app_config_t*, uint64_t ms) RLM_API_NOEXCEPT;
  RLM_API void realm_app_config_set_platform(realm_app_config_t*, const char*) RLM_API_NOEXCEPT;
  RLM_API void realm_app_config_set_platform_version(realm_app_config_t*, const char*) RLM_API_NOEXCEPT;
  RLM_API void realm_app_config_set_sdk_version(realm_app_config_t*, const char*) RLM_API_NOEXCEPT;
  
  /**
   * Get an existing @a realm_app_t* instance with the same app id, or create it with the
   * configuration if it doesn't exist.
   *
   * @return A non-null pointer if no error occurred.
   */
  RLM_API realm_app_t* realm_app_get(const realm_app_config_t*, const realm_sync_client_config_t*);
  
  /**
   * Get an existing @a realm_app_t* instance from the cache.
   *
   * @return Cached app instance, or null if no cached app exists for this @a app_id.
   */
  RLM_API realm_app_t* realm_app_get_cached(const char* app_id) RLM_API_NOEXCEPT;
  
  /**
   * Clear all the cached @a realm_app_t* instances in the process.
   *
   * @a realm_app_t* instances will need to be disposed with realm_release()
   * for them to be fully destroyed after the cache is cleared.
   */
  RLM_API void realm_clear_cached_apps(void) RLM_API_NOEXCEPT;
  
  RLM_API const char* realm_app_get_app_id(const realm_app_t*) RLM_API_NOEXCEPT;
  RLM_API realm_user_t* realm_app_get_current_user(const realm_app_t*) RLM_API_NOEXCEPT;
  
  /**
   * Get the list of active users in this @a app.
   *
   * @param out_users A pointer to an array of `realm_user_t*`, which
   *                  will be populated with the list of active users in the app.
   *                  May be NULL, in which case this function can be used to
   *                  discover the number of active users by passing in just `out_n`.
   * @param capacity The maximum number of elements `out_users` can hold.
   * @param out_n The actual number of entries written to `out_users`.
   *              May be NULL.
   * @return True if no exception occurred.
   */
  RLM_API bool realm_app_get_all_users(const realm_app_t* app, realm_user_t** out_users, size_t capacity,
                                       size_t* out_n);
  
  RLM_API bool realm_app_log_in_with_credentials(realm_app_t*, realm_app_credentials_t*,
                                                 realm_app_user_completion_func_t, void* userdata,
                                                 realm_free_userdata_func_t);
  
  RLM_API bool realm_app_log_out_current_user(realm_app_t*, realm_app_void_completion_func_t, void* userdata,
                                              realm_free_userdata_func_t);
  
  RLM_API bool realm_app_refresh_custom_data(realm_app_t*, realm_user_t*, realm_app_void_completion_func_t,
                                             void* userdata, realm_free_userdata_func_t);
  
  RLM_API bool realm_app_log_out(realm_app_t*, realm_user_t*, realm_app_void_completion_func_t, void* userdata,
                                 realm_free_userdata_func_t);
  
  RLM_API bool realm_app_link_user(realm_app_t*, realm_user_t*, realm_app_credentials_t*,
                                   realm_app_user_completion_func_t, void* userdata, realm_free_userdata_func_t);
  
  RLM_API bool realm_app_switch_user(realm_app_t*, realm_user_t*, realm_user_t** new_user);
  
  RLM_API bool realm_app_remove_user(realm_app_t*, realm_user_t*, realm_app_void_completion_func_t, void* userdata,
                                     realm_free_userdata_func_t);
  
  RLM_API bool realm_app_email_password_provider_client_register_email(realm_app_t*, const char* email,
                                                                       realm_string_t password,
                                                                       realm_app_void_completion_func_t, void* userdata,
                                                                       realm_free_userdata_func_t);
  
  RLM_API bool realm_app_email_password_provider_client_confirm_user(realm_app_t*, const char* token,
                                                                     const char* token_id,
                                                                     realm_app_void_completion_func_t, void* userdata,
                                                                     realm_free_userdata_func_t);
  
  RLM_API bool realm_app_email_password_provider_client_resend_confirmation_email(realm_app_t*, const char* email,
                                                                                  realm_app_void_completion_func_t,
                                                                                  void* userdata,
                                                                                  realm_free_userdata_func_t);
  
  RLM_API bool realm_app_email_password_provider_client_send_reset_password_email(realm_app_t*, const char* email,
                                                                                  realm_app_void_completion_func_t,
                                                                                  void* userdata,
                                                                                  realm_free_userdata_func_t);
  
  RLM_API bool realm_app_email_password_provider_client_retry_custom_confirmation(realm_app_t*, const char* email,
                                                                                  realm_app_void_completion_func_t,
                                                                                  void* userdata,
                                                                                  realm_free_userdata_func_t);
  
  RLM_API bool realm_app_email_password_provider_client_reset_password(realm_app_t*, realm_string_t password,
                                                                       const char* token, const char* token_id,
                                                                       realm_app_void_completion_func_t, void* userdata,
                                                                       realm_free_userdata_func_t);
  
  /**
   * Run the Email/Password Authentication provider's password reset function.
   *
   * @param serialized_ejson_payload The arguments array to invoke the function with,
   *                                 serialized as an Extended JSON string.
   * @return true, if no error occurred.
   */
  RLM_API bool realm_app_email_password_provider_client_call_reset_password_function(
      realm_app_t*, const char* email, realm_string_t password, const char* serialized_ejson_payload,
      realm_app_void_completion_func_t, void* userdata, realm_free_userdata_func_t);
  
  
  RLM_API bool realm_app_user_apikey_provider_client_create_apikey(const realm_app_t*, const realm_user_t*,
                                                                   const char* name,
                                                                   void (*)(void* userdata, realm_app_user_apikey_t*,
                                                                            const realm_app_error_t*),
                                                                   void* userdata, realm_free_userdata_func_t);
  
  RLM_API bool realm_app_user_apikey_provider_client_fetch_apikey(const realm_app_t*, const realm_user_t*,
                                                                  realm_object_id_t id,
                                                                  void (*)(void* userdata, realm_app_user_apikey_t*,
                                                                           const realm_app_error_t*),
                                                                  void* userdata, realm_free_userdata_func_t);
  
  RLM_API bool realm_app_user_apikey_provider_client_fetch_apikeys(const realm_app_t*, const realm_user_t*,
                                                                   void (*)(void* userdata, realm_app_user_apikey_t[],
                                                                            size_t count, realm_app_error_t*),
                                                                   void* userdata, realm_free_userdata_func_t);
  
  RLM_API bool realm_app_user_apikey_provider_client_delete_apikey(const realm_app_t*, const realm_user_t*,
                                                                   realm_object_id_t id,
                                                                   realm_app_void_completion_func_t, void* userdata,
                                                                   realm_free_userdata_func_t);
  
  RLM_API bool realm_app_user_apikey_provider_client_enable_apikey(const realm_app_t*, const realm_user_t*,
                                                                   realm_object_id_t id,
                                                                   realm_app_void_completion_func_t, void* userdata,
                                                                   realm_free_userdata_func_t);
  
  RLM_API bool realm_app_user_apikey_provider_client_disable_apikey(const realm_app_t*, const realm_user_t*,
                                                                    realm_object_id_t id,
                                                                    realm_app_void_completion_func_t, void* userdata,
                                                                    realm_free_userdata_func_t);
  
  RLM_API bool realm_app_push_notification_client_register_device(const realm_app_t*, const realm_user_t*,
                                                                  const char* service_name,
                                                                  const char* registration_token,
                                                                  realm_app_void_completion_func_t, void* userdata,
                                                                  realm_free_userdata_func_t);
  
  RLM_API bool realm_app_push_notification_client_deregister_device(const realm_app_t*, const realm_user_t*,
                                                                    const char* service_name,
                                                                    realm_app_void_completion_func_t, void* userdata,
                                                                    realm_free_userdata_func_t);
  
  /**
   * Run a named MongoDB Realm function.
   *
   * @param serialized_ejson_args The arguments array to invoke the function with,
   *                              serialized as an Extended JSON string.
   * @return true, if no error occurred.
   */
  RLM_API bool realm_app_call_function(const realm_app_t*, const realm_user_t*, const char* function_name,
                                       const char* serialized_ejson_args,
                                       void (*)(void* userdata, const char* serialized_ejson_response,
                                                const realm_app_error_t*),
                                       void* userdata, realm_free_userdata_func_t);
  
  /**
   * Instruct this app's sync client to immediately reconnect.
   * Useful when the device has been offline and then receives a network reachability update.
   *
   * The sync client will always attempt to reconnect eventually, this is just a hint.
   */
  RLM_API void realm_app_sync_client_reconnect(realm_app_t*) RLM_API_NOEXCEPT;
  
  /**
   * Get whether there are any active sync sessions for this app.
   */
  RLM_API bool realm_app_sync_client_has_sessions(const realm_app_t*) RLM_API_NOEXCEPT;
  
  /**
   * Wait until the sync client has terminated all sessions and released all realm files
   * it had open.
   *
   * WARNING: this is a blocking wait.
   */
  RLM_API void realm_app_sync_client_wait_for_sessions_to_terminate(realm_app_t*) RLM_API_NOEXCEPT;
  
  /**
   * Get the default realm file path based on the user and partition value in the config.
   *
   * @param custom_filename custom name for the realm file itself. Can be null,
   *                        in which case a default name based on the config will be used.
   *
   * Return value must be manually released with realm_free().
   */
  RLM_API char* realm_app_sync_client_get_default_file_path_for_realm(const realm_app_t*, const realm_sync_config_t*,
                                                                      const char* custom_filename) RLM_API_NOEXCEPT;
  
  RLM_API const char* realm_user_get_identity(const realm_user_t*) RLM_API_NOEXCEPT;
  
  RLM_API realm_user_state_e realm_user_get_state(const realm_user_t*) RLM_API_NOEXCEPT;
  
  typedef struct {
      const char* id;
      realm_auth_provider_e provider_type;
  } realm_user_identity_t;
  
  /**
   * Get the list of identities of this @a user.
   *
   * @param out_identities A pointer to an array of `realm_user_identity_t`, which
   *                       will be populated with the list of identities of this user.
   *                       May be NULL, in which case this function can be used to
   *                       discover the number of identities of this user by passing in NULL here
   *                       and examining `*out_n`.
   * @param capacity The maximum number of elements `out_identities` can hold.
   * @param out_n The actual number of entries written to `out_identities`. May be NULL.
   * @return true, if no errors occurred.
   */
  RLM_API bool realm_user_get_all_identities(const realm_user_t* user, realm_user_identity_t* out_identities,
                                             size_t capacity, size_t* out_n);
  
  RLM_API const char* realm_user_get_local_identity(const realm_user_t*) RLM_API_NOEXCEPT;
  
  // returned pointer must be manually released with realm_free()
  RLM_API char* realm_user_get_device_id(const realm_user_t*) RLM_API_NOEXCEPT;
  
  RLM_API realm_auth_provider_e realm_user_get_auth_provider(const realm_user_t*) RLM_API_NOEXCEPT;
  
  /**
   * Log out the user and mark it as logged out.
   *
   * Any active sync sessions associated with this user will be stopped.
   *
   * @return true, if no errors occurred.
   */
  RLM_API bool realm_user_log_out(realm_user_t*);
  
  RLM_API bool realm_user_is_logged_in(const realm_user_t*) RLM_API_NOEXCEPT;
  
  /**
   * Get the custom user data from the user's access token.
   *
   * Returned value must be manually released with realm_free().
   *
   * @return An Extended JSON document serialized as string,
   *         or null if token doesn't have any custom data.
   */
  RLM_API char* realm_user_get_custom_data(const realm_user_t*) RLM_API_NOEXCEPT;
  
  /**
   * Get the user profile associated with this user.
   *
   * Returned value must be manually released with realm_free().
   *
   * @return An Extended JSON document serialized as string,
   *         or null if an error occurred.
   */
  RLM_API char* realm_user_get_profile_data(const realm_user_t*);
  
  /* Sync */
  typedef enum realm_sync_client_metadata_mode {
      RLM_SYNC_CLIENT_METADATA_MODE_PLAINTEXT,
      RLM_SYNC_CLIENT_METADATA_MODE_ENCRYPTED,
      RLM_SYNC_CLIENT_METADATA_MODE_DISABLED,
  } realm_sync_client_metadata_mode_e;
  
  typedef enum realm_sync_client_reconnect_mode {
      RLM_SYNC_CLIENT_RECONNECT_MODE_NORMAL,
      RLM_SYNC_CLIENT_RECONNECT_MODE_TESTING,
  } realm_sync_client_reconnect_mode_e;
  
  typedef enum realm_sync_session_resync_mode {
      RLM_SYNC_SESSION_RESYNC_MODE_MANUAL,
      RLM_SYNC_SESSION_RESYNC_MODE_SEAMLESS_LOSS,
  } realm_sync_session_resync_mode_e;
  
  typedef enum realm_sync_session_stop_policy {
      RLM_SYNC_SESSION_STOP_POLICY_IMMEDIATELY,
      RLM_SYNC_SESSION_STOP_POLICY_LIVE_INDEFINITELY,
      RLM_SYNC_SESSION_STOP_POLICY_AFTER_CHANGES_UPLOADED,
  } realm_sync_session_stop_policy_e;
  
  typedef enum realm_sync_session_state {
      RLM_SYNC_SESSION_STATE_ACTIVE,
      RLM_SYNC_SESSION_STATE_DYING,
      RLM_SYNC_SESSION_STATE_INACTIVE,
      RLM_SYNC_SESSION_STATE_WAITING_FOR_ACCESS_TOKEN,
  } realm_sync_session_state_e;
  
  typedef enum realm_sync_connection_state {
      RLM_SYNC_CONNECTION_STATE_DISCONNECTED,
      RLM_SYNC_CONNECTION_STATE_CONNECTING,
      RLM_SYNC_CONNECTION_STATE_CONNECTED,
  } realm_sync_connection_state_e;
  
  typedef enum realm_sync_progress_direction {
      RLM_SYNC_PROGRESS_DIRECTION_UPLOAD,
      RLM_SYNC_PROGRESS_DIRECTION_DOWNLOAD,
  } realm_sync_progress_direction_e;
  
  /**
   * Possible error categories realm_sync_error_code_t can fall in.
   */
  typedef enum realm_sync_error_category {
      RLM_SYNC_ERROR_CATEGORY_CLIENT,
      RLM_SYNC_ERROR_CATEGORY_CONNECTION,
      RLM_SYNC_ERROR_CATEGORY_SESSION,
  
      /**
       * System error - POSIX errno, Win32 HRESULT, etc.
       */
      RLM_SYNC_ERROR_CATEGORY_SYSTEM,
  
      /**
       * Unknown source of error.
       */
      RLM_SYNC_ERROR_CATEGORY_UNKNOWN,
  } realm_sync_error_category_e;
  
  typedef enum realm_sync_errno_client {
      RLM_SYNC_ERR_CLIENT_CONNECTION_CLOSED = 100,
      RLM_SYNC_ERR_CLIENT_UNKNOWN_MESSAGE = 101,
      RLM_SYNC_ERR_CLIENT_BAD_SYNTAX = 102,
      RLM_SYNC_ERR_CLIENT_LIMITS_EXCEEDED = 103,
      RLM_SYNC_ERR_CLIENT_BAD_SESSION_IDENT = 104,
      RLM_SYNC_ERR_CLIENT_BAD_MESSAGE_ORDER = 105,
      RLM_SYNC_ERR_CLIENT_BAD_CLIENT_FILE_IDENT = 106,
      RLM_SYNC_ERR_CLIENT_BAD_PROGRESS = 107,
      RLM_SYNC_ERR_CLIENT_BAD_CHANGESET_HEADER_SYNTAX = 108,
      RLM_SYNC_ERR_CLIENT_BAD_CHANGESET_SIZE = 109,
      RLM_SYNC_ERR_CLIENT_BAD_ORIGIN_FILE_IDENT = 110,
      RLM_SYNC_ERR_CLIENT_BAD_SERVER_VERSION = 111,
      RLM_SYNC_ERR_CLIENT_BAD_CHANGESET = 112,
      RLM_SYNC_ERR_CLIENT_BAD_REQUEST_IDENT = 113,
      RLM_SYNC_ERR_CLIENT_BAD_ERROR_CODE = 114,
      RLM_SYNC_ERR_CLIENT_BAD_COMPRESSION = 115,
      RLM_SYNC_ERR_CLIENT_BAD_CLIENT_VERSION = 116,
      RLM_SYNC_ERR_CLIENT_SSL_SERVER_CERT_REJECTED = 117,
      RLM_SYNC_ERR_CLIENT_PONG_TIMEOUT = 118,
      RLM_SYNC_ERR_CLIENT_BAD_CLIENT_FILE_IDENT_SALT = 119,
      RLM_SYNC_ERR_CLIENT_BAD_FILE_IDENT = 120,
      RLM_SYNC_ERR_CLIENT_CONNECT_TIMEOUT = 121,
      RLM_SYNC_ERR_CLIENT_BAD_TIMESTAMP = 122,
      RLM_SYNC_ERR_CLIENT_BAD_PROTOCOL_FROM_SERVER = 123,
      RLM_SYNC_ERR_CLIENT_CLIENT_TOO_OLD_FOR_SERVER = 124,
      RLM_SYNC_ERR_CLIENT_CLIENT_TOO_NEW_FOR_SERVER = 125,
      RLM_SYNC_ERR_CLIENT_PROTOCOL_MISMATCH = 126,
      RLM_SYNC_ERR_CLIENT_BAD_STATE_MESSAGE = 127,
      RLM_SYNC_ERR_CLIENT_MISSING_PROTOCOL_FEATURE = 128,
      RLM_SYNC_ERR_CLIENT_HTTP_TUNNEL_FAILED = 131,
  } realm_sync_errno_client_e;
  
  typedef enum realm_sync_errno_connection {
      RLM_SYNC_ERR_CONNECTION_CONNECTION_CLOSED = 100,
      RLM_SYNC_ERR_CONNECTION_OTHER_ERROR = 101,
      RLM_SYNC_ERR_CONNECTION_UNKNOWN_MESSAGE = 102,
      RLM_SYNC_ERR_CONNECTION_BAD_SYNTAX = 103,
      RLM_SYNC_ERR_CONNECTION_LIMITS_EXCEEDED = 104,
      RLM_SYNC_ERR_CONNECTION_WRONG_PROTOCOL_VERSION = 105,
      RLM_SYNC_ERR_CONNECTION_BAD_SESSION_IDENT = 106,
      RLM_SYNC_ERR_CONNECTION_REUSE_OF_SESSION_IDENT = 107,
      RLM_SYNC_ERR_CONNECTION_BOUND_IN_OTHER_SESSION = 108,
      RLM_SYNC_ERR_CONNECTION_BAD_MESSAGE_ORDER = 109,
      RLM_SYNC_ERR_CONNECTION_BAD_DECOMPRESSION = 110,
      RLM_SYNC_ERR_CONNECTION_BAD_CHANGESET_HEADER_SYNTAX = 111,
      RLM_SYNC_ERR_CONNECTION_BAD_CHANGESET_SIZE = 112,
      RLM_SYNC_ERR_CONNECTION_BAD_CHANGESETS = 113,
  } realm_sync_errno_connection_e;
  
  typedef enum realm_sync_errno_session {
      RLM_SYNC_ERR_SESSION_SESSION_CLOSED = 200,
      RLM_SYNC_ERR_SESSION_OTHER_SESSION_ERROR = 201,
      RLM_SYNC_ERR_SESSION_TOKEN_EXPIRED = 202,
      RLM_SYNC_ERR_SESSION_BAD_AUTHENTICATION = 203,
      RLM_SYNC_ERR_SESSION_ILLEGAL_REALM_PATH = 204,
      RLM_SYNC_ERR_SESSION_NO_SUCH_REALM = 205,
      RLM_SYNC_ERR_SESSION_PERMISSION_DENIED = 206,
      RLM_SYNC_ERR_SESSION_BAD_SERVER_FILE_IDENT = 207,
      RLM_SYNC_ERR_SESSION_BAD_CLIENT_FILE_IDENT = 208,
      RLM_SYNC_ERR_SESSION_BAD_SERVER_VERSION = 209,
      RLM_SYNC_ERR_SESSION_BAD_CLIENT_VERSION = 210,
      RLM_SYNC_ERR_SESSION_DIVERGING_HISTORIES = 211,
      RLM_SYNC_ERR_SESSION_BAD_CHANGESET = 212,
      RLM_SYNC_ERR_SESSION_SUPERSEDED = 213,
      RLM_SYNC_ERR_SESSION_DISABLED_SESSION = 213,
      RLM_SYNC_ERR_SESSION_PARTIAL_SYNC_DISABLED = 214,
      RLM_SYNC_ERR_SESSION_UNSUPPORTED_SESSION_FEATURE = 215,
      RLM_SYNC_ERR_SESSION_BAD_ORIGIN_FILE_IDENT = 216,
      RLM_SYNC_ERR_SESSION_BAD_CLIENT_FILE = 217,
      RLM_SYNC_ERR_SESSION_SERVER_FILE_DELETED = 218,
      RLM_SYNC_ERR_SESSION_CLIENT_FILE_BLACKLISTED = 219,
      RLM_SYNC_ERR_SESSION_USER_BLACKLISTED = 220,
      RLM_SYNC_ERR_SESSION_TRANSACT_BEFORE_UPLOAD = 221,
      RLM_SYNC_ERR_SESSION_CLIENT_FILE_EXPIRED = 222,
      RLM_SYNC_ERR_SESSION_USER_MISMATCH = 223,
      RLM_SYNC_ERR_SESSION_TOO_MANY_SESSIONS = 224,
      RLM_SYNC_ERR_SESSION_INVALID_SCHEMA_CHANGE = 225,
  } realm_sync_errno_session_e;
  
  typedef struct realm_sync_session realm_sync_session_t;
  typedef struct realm_async_open_task realm_async_open_task_t;
  
  // This type should never be returned from a function.
  // It's only meant as an asynchronous callback argument.
  // Pointers to this struct and its pointer members are only valid inside the scope
  // of the callback they were passed to.
  typedef struct realm_sync_error_code {
      realm_sync_error_category_e category;
      int value;
      const char* message;
  } realm_sync_error_code_t;
  
  typedef struct realm_sync_error_user_info {
      const char* key;
      const char* value;
  } realm_sync_error_user_info_t;
  
  // This type should never be returned from a function.
  // It's only meant as an asynchronous callback argument.
  // Pointers to this struct and its pointer members are only valid inside the scope
  // of the callback they were passed to.
  typedef struct realm_sync_error {
      realm_sync_error_code_t error_code;
      const char* detailed_message;
      bool is_fatal;
      bool is_unrecognized_by_client;
  
      realm_sync_error_user_info_t* user_info_map;
      size_t user_info_length;
  } realm_sync_error_t;
  
  typedef void (*realm_sync_upload_completion_func_t)(void* userdata, realm_sync_error_code_t*);
  typedef void (*realm_sync_download_completion_func_t)(void* userdata, realm_sync_error_code_t*);
  typedef void (*realm_sync_connection_state_changed_func_t)(void* userdata, realm_sync_connection_state_e old_state,
                                                             realm_sync_connection_state_e new_state);
  typedef void (*realm_sync_session_state_changed_func_t)(void* userdata, realm_sync_session_state_e old_state,
                                                          realm_sync_session_state_e new_state);
  typedef void (*realm_sync_progress_func_t)(void* userdata, uint64_t transferred_bytes, uint64_t total_bytes);
  typedef void (*realm_sync_error_handler_func_t)(void* userdata, realm_sync_session_t*, const realm_sync_error_t);
  typedef bool (*realm_sync_ssl_verify_func_t)(void* userdata, const char* server_address, short server_port,
                                               const char* pem_data, size_t pem_size, int preverify_ok, int depth);
  
  /**
   * Callback function invoked by the async open task once the realm is open and fully synchronized.
   *
   * This callback is invoked on the sync client's worker thread.
   *
   * @param realm Downloaded realm instance, or null if an error occurred.
   *              Move to the thread you want to use it on and
   *              thaw with @a realm_from_thread_safe_reference().
   * @param error Null, if the operation complete successfully.
   */
  typedef void (*realm_async_open_task_completion_func_t)(void* userdata, realm_thread_safe_reference_t* realm,
                                                          const realm_async_error_t* error);
  
  RLM_API realm_sync_client_config_t* realm_sync_client_config_new(void) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_base_file_path(realm_sync_client_config_t*, const char*) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_metadata_mode(realm_sync_client_config_t*,
                                                          realm_sync_client_metadata_mode_e) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_metadata_encryption_key(realm_sync_client_config_t*,
                                                                    const uint8_t[64]) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_reset_metadata_on_error(realm_sync_client_config_t*, bool) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_log_callback(realm_sync_client_config_t*, realm_log_func_t, void* userdata,
                                                         realm_free_userdata_func_t) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_log_level(realm_sync_client_config_t*, realm_log_level_e) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_reconnect_mode(realm_sync_client_config_t*,
                                                           realm_sync_client_reconnect_mode_e) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_multiplex_sessions(realm_sync_client_config_t*, bool) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_user_agent_binding_info(realm_sync_client_config_t*,
                                                                    const char*) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_user_agent_application_info(realm_sync_client_config_t*,
                                                                        const char*) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_connect_timeout(realm_sync_client_config_t*, uint64_t) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_connection_linger_time(realm_sync_client_config_t*,
                                                                   uint64_t) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_ping_keepalive_period(realm_sync_client_config_t*,
                                                                  uint64_t) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_pong_keepalive_timeout(realm_sync_client_config_t*,
                                                                   uint64_t) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_client_config_set_fast_reconnect_limit(realm_sync_client_config_t*,
                                                                 uint64_t) RLM_API_NOEXCEPT;
  
  RLM_API realm_sync_config_t* realm_sync_config_new(const realm_user_t*, const char* partition_value) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_config_set_session_stop_policy(realm_sync_config_t*,
                                                         realm_sync_session_stop_policy_e) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_config_set_error_handler(realm_sync_config_t*, realm_sync_error_handler_func_t,
                                                   void* userdata, realm_free_userdata_func_t) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_config_set_client_validate_ssl(realm_sync_config_t*, bool) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_config_set_ssl_trust_certificate_path(realm_sync_config_t*, const char*) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_config_set_ssl_verify_callback(realm_sync_config_t*, realm_sync_ssl_verify_func_t,
                                                         void* userdata, realm_free_userdata_func_t) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_config_set_cancel_waits_on_nonfatal_error(realm_sync_config_t*, bool) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_config_set_authorization_header_name(realm_sync_config_t*, const char*) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_config_set_custom_http_header(realm_sync_config_t*, const char* name,
                                                        const char* value) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_config_set_recovery_directory_path(realm_sync_config_t*, const char*) RLM_API_NOEXCEPT;
  RLM_API void realm_sync_config_set_resync_mode(realm_sync_config_t*,
                                                 realm_sync_session_resync_mode_e) RLM_API_NOEXCEPT;
  
  /**
   * Create a task that will open a realm with the specific configuration
   * and also download all changes from the sync server.
   *
   * Use @a realm_async_open_task_start() to start the download process.
   */
  RLM_API realm_async_open_task_t* realm_open_synchronized(realm_config_t*) RLM_API_NOEXCEPT;
  RLM_API void realm_async_open_task_start(realm_async_open_task_t*, realm_async_open_task_completion_func_t,
                                           void* userdata, realm_free_userdata_func_t) RLM_API_NOEXCEPT;
  RLM_API void realm_async_open_task_cancel(realm_async_open_task_t*) RLM_API_NOEXCEPT;
  RLM_API uint64_t realm_async_open_task_register_download_progress_notifier(
      realm_async_open_task_t*, realm_sync_progress_func_t, void* userdata,
      realm_free_userdata_func_t) RLM_API_NOEXCEPT;
  RLM_API void realm_async_open_task_unregister_download_progress_notifier(realm_async_open_task_t*,
                                                                           uint64_t token) RLM_API_NOEXCEPT;
  
  /**
   * Get the sync session for a specific realm.
   *
   * This function will not fail if the realm wasn't open with a sync configuration in place,
   * but just return NULL;
   *
   * @return A non-null pointer if a session exists.
   */
  RLM_API realm_sync_session_t* realm_sync_session_get(const realm_t*) RLM_API_NOEXCEPT;
  
  RLM_API realm_sync_session_state_e realm_sync_session_get_state(const realm_sync_session_t*) RLM_API_NOEXCEPT;
  
  RLM_API realm_sync_connection_state_e realm_sync_session_get_connection_state(const realm_sync_session_t*)
      RLM_API_NOEXCEPT;
  
  RLM_API realm_user_t* realm_sync_session_get_user(const realm_sync_session_t*) RLM_API_NOEXCEPT;
  
  RLM_API const char* realm_sync_session_get_partition_value(const realm_sync_session_t*) RLM_API_NOEXCEPT;
  
  /**
   * Get the filesystem path of the realm file backing this session.
   */
  RLM_API const char* realm_sync_session_get_file_path(const realm_sync_session_t*) RLM_API_NOEXCEPT;
  
  /**
   * Ask the session to pause synchronization.
   *
   * No-op if the session is already inactive.
   */
  RLM_API void realm_sync_session_pause(realm_sync_session_t*) RLM_API_NOEXCEPT;
  
  /**
   * Ask the session to resume synchronization.
   *
   * No-op if the session is already active.
   */
  RLM_API void realm_sync_session_resume(realm_sync_session_t*) RLM_API_NOEXCEPT;
  
  /**
   * Register a callback that will be invoked every time the session's connection state changes.
   *
   * @return A token value that can be used to unregiser the callback.
   */
  RLM_API uint64_t realm_sync_session_register_connection_state_change_callback(
      realm_sync_session_t*, realm_sync_connection_state_changed_func_t, void* userdata,
      realm_free_userdata_func_t userdata_free) RLM_API_NOEXCEPT;
  
  RLM_API void realm_sync_session_unregister_connection_state_change_callback(realm_sync_session_t*,
                                                                              uint64_t token) RLM_API_NOEXCEPT;
  
  /**
   * Register a callback that will be invoked every time the session reports progress.
   *
   * @param is_streaming If true, then the notifier will be called forever, and will
   *                     always contain the most up-to-date number of downloadable or uploadable bytes.
   *                     Otherwise, the number of downloaded or uploaded bytes will always be reported
   *                     relative to the number of downloadable or uploadable bytes at the point in time
   *                     when the notifier was registered.
   * @return A token value that can be used to unregiser the notifier.
   */
  RLM_API uint64_t realm_sync_session_register_progress_notifier(
      realm_sync_session_t*, realm_sync_progress_func_t, realm_sync_progress_direction_e, bool is_streaming,
      void* userdata, realm_free_userdata_func_t userdata_free) RLM_API_NOEXCEPT;
  
  RLM_API void realm_sync_session_unregister_progress_notifier(realm_sync_session_t*, uint64_t token) RLM_API_NOEXCEPT;
  
  /**
   * Register a callback that will be invoked when all pending downloads have completed.
   */
  RLM_API void
  realm_sync_session_wait_for_download_completion(realm_sync_session_t*, realm_sync_download_completion_func_t,
                                                  void* userdata,
                                                  realm_free_userdata_func_t userdata_free) RLM_API_NOEXCEPT;
  
  /**
   * Register a callback that will be invoked when all pending uploads have completed.
   */
  RLM_API void realm_sync_session_wait_for_upload_completion(realm_sync_session_t*, realm_sync_upload_completion_func_t,
                                                             void* userdata,
                                                             realm_free_userdata_func_t userdata_free) RLM_API_NOEXCEPT;
  
  
  #endif // REALM_H