FastDFS非常适合存储大量的小文件，遗憾的是本身不支持自定义文件名，文件名是存储成功以后根据存储位置生成的一个file_id。很多应用场景不得不使用自定义文件名，在不修改其源码的情况下，可以在存储客户端fdfs_client增加一个用来存储自定义文件名和fastdfs的file_id之间的映射关系的数据库间接实现自定义文件名的存取和访问，在这里我们选用了reids。顺便说一下，淘宝也有一个类似于FastDFS的文件存储系统TFS，对于自定义文件名，它是用mysql来存储映射关系的，我认为在高并发访问下mysql本身就是瓶颈，因此在这个方案中采用了redis。
准备工作：
fastdfs环境安装...略...（官方：https://code.google.com/p/fastdfs/）
redis环境安装...略...(官方：http://redis.io/)
用python实现，因此需要安装fastdfs的python客户端(下载：https://fastdfs.googlecode.com/files/fdfs_client-py-1.2.6.tar.gz)
python的redis客户端，到https://pypi.python.org/pypi/redis下载
# -*- coding: utf-8 -*- import setting from fdfs_client.client import * from fdfs_client.exceptions import * from fdfs_client.connection import * import redis import time import logging import random logging.basicConfig(format='[%(levelname)s]: %(message)s', level=logging.DEBUG) logger = logging.getLogger(__name__) logger.setLevel(logging.DEBUG) class RedisError(Exception): def __init__(self, value): self.value = value def __str__(self): return repr(self.value) class fastdfsClient(Fdfs_client): def __init__(self): self.tracker_pool = ConnectionPool(**setting.fdfs_tracker) self.timeout = setting.fdfs_tracker['timeout'] return None def __del__(self): try: self.pool.destroy() self.pool = None except: pass class fastdfs(object): def __init__(self): ''' conf_file:配置文件 ''' self.fdfs_client = fastdfsClient() self.fdfs_redis = [] for i in setting.fdfs_redis_dbs: self.fdfs_redis.append(redis.Redis(host=i[0], port=i[1], db=i[2])) def store_by_buffer(self,buf,filename=None,file_ext_name = None): ''' buffer存储文件 参数： filename:自定义文件名，如果不指定，将远程file_id作为文件名 file_ext_name:文件扩展名（可选），如果不指定，将根据自定义文件名智能判断 返回值： { 'group':组名, 'file_id':不含组名的文件ID, 'size':文件尺寸, 'upload_time':上传时间 } ''' if filename and random.choice(self.fdfs_redis).exists(filename): logger.info('File(%s) exists.'%filename) return random.choice(self.fdfs_redis).hgetall(filename) t1 = time.time() # try: ret_dict = self.fdfs_client.upload_by_buffer(buf,file_ext_name) # except Exception,e: # logger.error('Error occurred while uploading: %s'%e.message) # return None t2 = time.time() logger.info('Upload file(%s) by buffer, time consume: %fs' % (filename,(t2 - t1))) for key in ret_dict: logger.debug('[+] %s : %s' % (key, ret_dict[key])) stored_filename = ret_dict['Remote file_id'] stored_filename_without_group = stored_filename[stored_filename.index('/')+1:] if not filename: filename =stored_filename_without_group vmp = {'group':ret_dict['Group name'],'file_id':stored_filename_without_group,'size':ret_dict['Uploaded size'],'upload_time':int(time.time()*1000)} try: for i in self.fdfs_redis: if not i.hmset(filename,vmp): raise RedisError('Save Failure') logger.info('Store file(%s) by buffer successful' % filename) except Exception,e: logger.error('Save info to Redis failure. rollback...') try: ret_dict = self.fdfs_client.delete_file(stored_filename) except Exception,e: logger.error('Error occurred while deleting: %s'%e.message) return None return vmp def remove(self,filename): ''' 删除文件, filename是用户自定义文件名 return True|False ''' fileinfo = random.choice(self.fdfs_redis).hgetall(filename) stored_filename = '%s/%s'%(fileinfo['group'],fileinfo['file_id']) try: ret_dict = self.fdfs_client.delete_file(stored_filename) logger.info('Remove stored file successful') except Exception,e: logger.error('Error occurred while deleting: %s'%e.message) return False for i in self.fdfs_redis: if not i.delete(filename): logger.error('Remove fileinfo in redis failure') logger.info('%s removed.'%filename) return True def download(self,filename): ''' 下载文件 返回二进制 ''' finfo = self.getInfo(filename) if finfo: ret = self.fdfs_client.download_to_buffer('%s/%s'%(finfo['group'],finfo['file_id'])) return ret['Content'] else: logger.debug('%s is not exists'%filename) return None def list(self,pattern='*'): ''' 列出文件列表 ''' return random.choice(self.fdfs_redis).keys(pattern) def getInfo(self,filename): ''' 获得文件信息 return:{ 'group':组名, 'file_id':不含组名的文件ID, 'size':文件尺寸, 'upload_time':上传时间 } ''' return random.choice(self.fdfs_redis).hgetall(filename)
配置：
# -*- coding: utf-8 -*- #fastdfs tracker, multiple tracker supported fdfs_tracker = { 'host_tuple':('192.168.2.233','192.168.2.234'), 'port':22122, 'timeout':30, 'name':'Tracker Pool' } #fastdfs meta db, multiple redisdb supported fdfs_redis_dbs = ( ('192.168.2.233',6379,0), ('192.168.2.233',6379,1) )
