diff --git a/tdlib.py b/tdlib.py
index 103551e..903e70d 100644
--- a/tdlib.py
+++ b/tdlib.py
@@ -641,6 +641,21 @@ class TdLib:
                 print(f"{re['code']} {re['message']}")
             return None
 
+    async def getMessageLink(self, chat_id: int, message_id: int,
+                             media_timestamp: int = 0, for_album: bool = False,
+                             for_comment: bool = False):
+        re = await self._send({"@type": "getMessageLink", "chat_id": chat_id,
+                               "message_id": message_id,
+                               "media_timestamp": media_timestamp,
+                               "for_album": for_album,
+                               "for_comment": for_comment})
+        if re['@type'] == 'messageLink':
+            return re
+        else:
+            if re['@type'] == 'error':
+                print(f"{re['code']} {re['message']}")
+            return None
+
     async def getProxies(self):
         while not self._db_initalized:
             await asyncio.sleep(0.1)
@@ -719,6 +734,32 @@ class TdLib:
             else:
                 raise ValueError("Unknown authorization_state", state)
 
+    async def optimizeStorage(self, size: int = -1, ttl: int = -1,
+                              count: int = -1, immunity_delay: int = -1,
+                              file_types: list = None,
+                              chat_ids: List[int] = None,
+                              exclude_chat_ids: List[int] = None,
+                              return_deleted_file_statistics: bool = False,
+                              chat_limit: int = None):
+        d = {"@type": "optimizeStorage", "size": size, "ttl": ttl,
+             "count": count, "immunity_delay": immunity_delay,
+             "return_deleted_file_statistics": return_deleted_file_statistics}
+        if file_types is not None:
+            d['file_types'] = file_types
+        if chat_ids is not None:
+            d['chat_ids'] = chat_ids
+        if exclude_chat_ids is not None:
+            d['exclude_chat_ids'] = exclude_chat_ids
+        if chat_limit is not None:
+            d['chat_limit'] = chat_limit
+        re = await self._send(d)
+        if re['@type'] == 'storageStatistics':
+            return re
+        else:
+            if re['@type'] == 'error':
+                print(f"{re['code']} {re['message']}")
+            return None
+
     async def parseMarkdown(self, text: str):
         re = await self._send({"@type": "parseMarkdown", "text": text})
         if re['@type'] == 'formattedText':
@@ -839,6 +880,16 @@ class TdLib:
                 print(f"{re['code']} {re['message']}")
             return False
 
+    async def setDatabaseEncryptionKey(self,
+                                       new_encryption_key: Union[str, bytes]):
+        re = await self._send({"@type": "setDatabaseEncryptionKey", "new_encryption_key": new_encryption_key})  # noqa: E501
+        if re['@type'] == 'ok':
+            return True
+        else:
+            if re['@type'] == 'error':
+                print(f"{re['code']} {re['message']}")
+            return False
+
     async def setProxy(self, server, port, type):
         while not self._db_initalized:
             await asyncio.sleep(0.1)
diff --git a/tg_user_bot.py b/tg_user_bot.py
index ce52cf9..dba4687 100644
--- a/tg_user_bot.py
+++ b/tg_user_bot.py
@@ -1,5 +1,6 @@
 from argparse import ArgumentParser
 import asyncio
+from html import escape
 from json import load
 from re import I, compile
 from traceback import format_exc
@@ -13,6 +14,7 @@ from tdlib import (
     TdLib,
     TextParseMode,
 )
+from time import time
 from util import commandLineToArgv, timeToStr, tparse
 import requests
 
@@ -65,6 +67,21 @@ damm.add_argument('-e', '--end-time', type=tparse, metavar='TIME', help="The mes
 nbnhhsh = MyArgParser('-nbnhhsh', description='「能不能好好说话？」 拼音首字母缩写翻译工具', add_help=False)  # noqa: E501
 nbnhhsh.add_argument('缩写', help='缩写形式')
 nbnhhsh.add_argument('-t', '--timeout', help='设置超时时长，单位为秒（默认为 5 秒）', default=5, type=int, metavar='时长', dest='timeout')  # noqa: E501
+sm = MyArgParser('-searchmessage', description='Search message in a chat.', add_help=False)  # noqa: E501
+sm.add_argument('keyword', help='Sepcify the keyword.')
+sm.add_argument('-c', '--chat_id', help='Specify the chat to search.', type=int, metavar='ID', dest='chat_id')  # noqa: E501
+sm.add_argument('-m', '--max_searched', help='Specify the maximum count of messages to searched. -1 if unlimited. (Default: 1000)', type=int, default=1000, metavar='COUNT', dest='max_searched')  # noqa: E501
+om = MyArgParser('-optimizestorage', description='Optimizes storage usage for tdlib (user bot).', add_help=False)  # noqa: E501
+om.add_argument('-h', '--help', help='Print this message.', action='store_true', dest='help')  # noqa: E501
+om.add_argument('-s', '--size', help='Limit on the total size of files after deletion, in bytes.', type=int, metavar='BYTES', dest='size')  # noqa: E501
+om.add_argument('-t', '--ttl', help='Limit on the time that has passed since the last time a file was accessed (or creation time for some filesystems).', type=int, metavar='TIME', dest='ttl')  # noqa: E501
+om.add_argument('-c', '--count', help='Limit on the total count of files after deletion.', type=int, metavar='COUNT', dest='count')  # noqa: E501
+om.add_argument('-i', '--immunity_delay', help="The amount of time after the creation of a file during which it can't be deleted, in seconds.", type=int, metavar='TIME', dest='immunity_delay')  # noqa: E501
+om.add_argument('-C', '--chat_ids', help='If non-empty, only files from the given chats are considered. Use 0 as chat identifier to delete files not belonging to any chat (e.g., profile photos).', action='append', type=int, metavar='ID', dest='chat_ids')  # noqa: E501
+om.add_argument('-e', '--exclude_chat_ids', help='If non-empty, files from the given chats are excluded. Use 0 as chat identifier to exclude all files not belonging to any chat (e.g., profile photos).', action='append', type=int, metavar='ID', dest='exclude_chat_ids')  # noqa: E501
+om.add_argument('-r', '--return_deleted_file_statistics', help='Specifiy it if statistics about the files that were deleted must be returned instead of the whole storage usage statistics. Affects only returned statistics.', action='store_true', dest='return_deleted_file_statistics')  # noqa: E501
+om.add_argument('--chat_limit', help='The maximum number of chats with the largest storage usage for which separate statistics need to be returned.', type=int, metavar='COUNT', dest='chat_limit')  # noqa: E501
+om.add_argument('-R', '--robot', help="Optimize for robot's storage rather than user.", action='store_true', dest='robot')  # noqa: E501
 
 
 def generateFileInfo(f: dict) -> str:
@@ -388,6 +405,107 @@ async def handle_nbnhhsh(lib: TdLib, mes: dict, argv: List[str]):
         print('Can not edit message.')
 
 
+async def handle_search_message(lib: TdLib, mes: dict, argv: List[str]):
+    if len(argv) == 1:
+        re = await lib.editMessageText(
+            mes['chat_id'], mes['id'], f"```\n{sm.format_help()}\n```",
+            TextParseMode.MarkDown)
+    else:
+        try:
+            opt = sm.parse_intermixed_args(argv[1:])
+            chat_id = opt.chat_id if opt.chat_id else mes['chat_id']
+            await lib.editMessageText(mes['chat_id'], mes['id'], f'Started to search `{opt.keyword}`.', TextParseMode.MarkDown)  # noqa: E501
+            mess: List[int] = []
+            tmes = 0
+            st: int = None
+            et: int = None
+            fmi: int = None
+            n = time()
+            while True:
+                mesl = await lib.searchChatMessages(chat_id, from_message_id=fmi, limit=100)  # noqa: 
+                if mesl is None or len(mesl['messages']) == 0:
+                    break
+                fmi = mesl['messages'][-1]['id']
+                for nmes in mesl['messages']:
+                    if nmes['content']['@type'] != 'messageText':
+                        continue
+                    if nmes['id'] == mes['id']:
+                        continue
+                    tmes += 1
+                    if st is None or st > nmes['date']:
+                        st = nmes['date']
+                    if et is None or et < nmes['date']:
+                        et = nmes['date']
+                    text: str = nmes['content']['text']['text']
+                    if text.find(opt.keyword) > -1:
+                        mess.append(nmes['id'])
+                if (opt.max_searched > -1 and tmes >= opt.max_searched) or len(mess) >= 20:  # noqa: E501
+                    break
+                if n + 10 < time():
+                    await lib.editMessageText(mes['chat_id'], mes['id'], f'Search `{opt.keyword}`...\nAlready searched `{tmes}` messages, founded `{len(mess)}` result.', TextParseMode.MarkDown)  # noqa: E501
+                    n = time()
+            tmp = '' if tmes == 0 else f" (from <code>{timeToStr(st)}</code> to <code>{timeToStr(et)}</code>)"  # noqa: E501
+            r = f"Searched <code>{escape(opt.keyword)}</code> in <code>{tmes}</code> messages{tmp}, founded <code>{len(mess)}</code> results:"  # noqa: E501
+            for i in mess:
+                link = await lib.getMessageLink(chat_id, i)
+                if link is None:
+                    r += "\nFailed to get message link."
+                else:
+                    r += f"\n{escape(link['link'])}"
+            re = await lib.editMessageText(mes['chat_id'], mes['id'], r, TextParseMode.HTML)  # noqa: E501
+        except ValueError as e:
+            if len(e.args) == 0:
+                re = await lib.editMessageText(mes['chat_id'], mes['id'], "Unknown error.")  # noqa: E501
+            else:
+                re = await lib.editMessageText(mes['chat_id'], mes['id'], f"```\n{sm.format_usage()}{sm.prog}: error: {e.args[0] if len(e.args) == 1 else e.args}\n```", TextParseMode.MarkDown)  # noqa: E501
+        except Exception:
+            re = await lib.editMessageText(mes['chat_id'], mes['id'], f"```\n{format_exc()}\n```", TextParseMode.MarkDown)  # noqa: E501
+    if re is None:
+        print('Can not edit message.')
+
+
+async def handle_optimize_storage(lib: TdLib, robot: TdLib, mes: dict,
+                                  argv: List[str]):
+    try:
+        opt = om.parse_intermixed_args(argv[1:])
+        if opt.help:
+            re = await lib.editMessageText(
+                mes['chat_id'], mes['id'], f"```\n{om.format_help()}\n```",
+                TextParseMode.MarkDown)
+        else:
+            if opt.robot and not robot._logined:
+                raise ValueError('Robot is not logined.')
+            d = {'return_deleted_file_statistics': opt.return_deleted_file_statistics}  # noqa: E501
+            if opt.size:
+                d['size'] = opt.size
+            if opt.ttl:
+                d['ttl'] = opt.ttl
+            if opt.count:
+                d['count'] = opt.count
+            if opt.immunity_delay:
+                d['immunity_delay'] = opt.immunity_delay
+            if opt.chat_ids:
+                d['chat_ids'] = opt.chat_ids
+            if opt.exclude_chat_ids:
+                d['exclude_chat_ids'] = opt.exclude_chat_ids
+            if opt.chat_limit:
+                d['chat_limit'] = opt.chat_limit
+            r = await robot.optimizeStorage(**d) if opt.robot else await lib.optimizeStorage(**d)  # noqa: E501
+            if r is None:
+                raise ValueError('Failed to optimize the storage.')
+            text = f"Optimized successfully.\nTotal file size: <code>{r['size']}B</code>\nFile count: <code>{r['count']}</code>"  # noqa: E501
+            re = await lib.editMessageText(mes['chat_id'], mes['id'], text, TextParseMode.HTML)  # noqa: E501
+    except ValueError as e:
+        if len(e.args) == 0:
+            re = await lib.editMessageText(mes['chat_id'], mes['id'], "Unknown error.")  # noqa: E501
+        else:
+            re = await lib.editMessageText(mes['chat_id'], mes['id'], f"```\n{om.format_usage()}{om.prog}: error: {e.args[0] if len(e.args) == 1 else e.args}\n```", TextParseMode.MarkDown)  # noqa: E501
+    except Exception:
+        re = await lib.editMessageText(mes['chat_id'], mes['id'], f"```\n{format_exc()}\n```", TextParseMode.MarkDown)  # noqa: E501
+    if re is None:
+        print('Can not edit message.')
+
+
 async def main(lib: TdLib, robot: TdLib):
     with open('tdlib.json', 'r', encoding='UTF-8') as f:
         se = load(f)
@@ -440,6 +558,10 @@ async def main(lib: TdLib, robot: TdLib):
                     asyncio.create_task(re)
                 elif argv[0] == '-nbnhhsh':
                     asyncio.create_task(handle_nbnhhsh(lib, mes, argv))
+                elif argv[0] in ['-searchmessage', '-sm']:
+                    asyncio.create_task(handle_search_message(lib, mes, argv))
+                elif argv[0] in ['-optimizestorage', '-om']:
+                    asyncio.create_task(handle_optimize_storage(lib, robot, mes, argv))  # noqa: E501
 
 
 with TdLib() as lib: