Refactoring of redis-sharp for extensibility

[rfranke]

The current source file redis-sharp.cs defines two classes in the global namespace: Redis and SortOptions. The combination of basic client communication and protocal handling with specific client commands in one class Redis makes it hard to add different kinds of clients. A separate client connection only using specific commands is needed for Redis pub/sub messaging. See also pull requests #4, #8, #9. Alternative existing C# clients provide a deeper integration with C# features. They all start from scratch regarding the general client interface though.

Currently the class Redis defines:

class Redis

• enum KeyType
• class ResponseException
• Redis (host, port), Redis (host), Redis
• Db
• Set, SetNX
• MSet (implements encoding of key/value tuples, call SendDataRESP)
• Get
• Sort
• GetSet
• ReadLine
• Connect
• SendDataCommand (call SendDataRESP)
• SendDataRESP (implement send to socket)
• SendCommand (re-implement send to socket)
• Log
• ExpectSuccess
• SendExpectSuccess
• SendDataExpectInt
• SendExpectInt
• SendExpectString
• SendGetString
• SendExpectData
• ReadData
• ContainsKey
• Remove
• Increment
• Decrement
• TypeOf
• RandomKey
• Rename
• Expire
• ExpireAt
• TimeToLive
• DbSize
• Save
• BackgroundSave
• Shutdown
• FlushAll
• FlushDb
• LastSave
• GetInfo
• Keys
• GetKeys
• MGet
• SendExpectStringArray
• SendExpectDataArray
• #region List commands
• #region Set commands
• Dispose (call QUIT and close socket)

class SortOptions

RedisSharp is out-standing for it's simplicity, which should be kept. Advanced C# features, like an asynchronous client or deeper integration with C# data structures, can go on top of a common basic C# client interface.

This is why the class Redis should be split into two classes: one for basic client communication and a second for specific commands. Moreover, if more classes get defined, including also classes with generic names like SortOptions, then they should be grouped in a namespace.

The grouping could be (bold face marks new things):

namespace RedisSharp
class RedisClient -- cf. redis-cli just providing communication and encoding

• class ResponseException
• RedisClient (host, port), RedisClient (host), RedisClient
• Log
• Connect
• SendDataRESP --> SendRaw (implement send to socket once)
• SendTuplesCommand (separate encoding of key/value tuples from MSet and call SendRaw)
• SendDataCommand (assemble byte array and call SendRaw)
• SendCommand (assemble byte array and call SendRaw)
• ReadLine
• ExpectSuccess
• SendExpectSuccess
• SendDataExpectInt
• SendExpectInt
• SendExpectString
• SendGetString
• SendExpectData
• ReadData
• SendExpectStringArray
• SendExpectDataArray
• Dispose (close socket)

class Redis : RedisClient

• enum KeyType
• Redis (host, port), Redis (host), Redis
• Db
• Set, SetNX
• MSet (call SendTuplesCommand)
• Get
• Sort
• GetSet
• ContainsKey
• Remove
• Increment
• Decrement
• TypeOf
• RandomKey
• Rename
• Expire
• ExpireAt
• TimeToLive
• DbSize
• Save
• BackgroundSave
• Shutdown
• FlushAll
• FlushDb
• LastSave
• GetInfo
• Keys
• GetKeys
• MGet
• #region List commands
• #region Set commands
• Dispose (call QUIT)

SortOptions

The separation of redis-sharp.cs into two files RedisClient.cs and Redis.cs makes it hard to track changes, because methods move (like the Set commands from on top of RedisClient.Connect into Redis extending from RedisClient. Moreover the indentation changes with a namespace. This is why the opportunity could be used to introduce more moves and group the Redis commands according to the Redis documentation into regions Keys, Strings, Connection, Server (see http://www.redis.io/commands). One might also introduce separate regions for 1:1 implementations of Redis commands -- like Set (key, value) -- and C# extendsions -- like Set (dictionary).

Alternative client implementations can then extend from RedisClient as well, e.g.:

namespace RedisSharp
RedisSub : RedisClient

• RedisSub (host, port), RedisSub (host), RedisSub ()
• #region Sub commands (Subscribe, PSubscribe, Unsubscribe, PUnsubscribe)
• MessageReceived
• SubscripeReceived
• UnsubscribeReceived
• OnMessageReceived
• OnSubscripeReceived
• OnUnsubscribeReceived
• SendSubCommand (call SendCommand and start/stop listening)
• SubWorker (read messages emit events)
• Dispose (stop listening)

RedisSubEventArgs