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Jedis 源代码阅读一 —— Jedis

时间:2017-08-21 11:50:24      阅读:307      评论:0      收藏:0      [点我收藏+]

这是jedis 源代码文件夹,我们接下来选择性阅读重要的接口以及实现。

└─redis
    └─clients
        ├─jedis
        │  │  BinaryClient.java
        │  │  BinaryJedis.java
        │  │  BinaryJedisCluster.java
        │  │  BinaryJedisPubSub.java
        │  │  BinaryShardedJedis.java
        │  │  BitOP.java
        │  │  BitPosParams.java
        │  │  Builder.java
        │  │  BuilderFactory.java
        │  │  Client.java
        │  │  Connection.java
        │  │  DebugParams.java
        │  │  GeoCoordinate.java
        │  │  GeoRadiusResponse.java
        │  │  GeoUnit.java
        │  │  HostAndPort.java
        │  │  Jedis.java
        │  │  JedisCluster.java
        │  │  JedisClusterCommand.java
        │  │  JedisClusterConnectionHandler.java
        │  │  JedisClusterInfoCache.java
        │  │  JedisFactory.java
        │  │  JedisMonitor.java
        │  │  JedisPool.java
        │  │  JedisPoolAbstract.java
        │  │  JedisPoolConfig.java
        │  │  JedisPubSub.java
        │  │  JedisSentinelPool.java
        │  │  JedisShardInfo.java
        │  │  JedisSlotBasedConnectionHandler.java
        │  │  MultiKeyPipelineBase.java
        │  │  Pipeline.java
        │  │  PipelineBase.java
        │  │  Protocol.java
        │  │  Queable.java
        │  │  Response.java
        │  │  ScanParams.java
        │  │  ScanResult.java
        │  │  ShardedJedis.java
        │  │  ShardedJedisPipeline.java
        │  │  ShardedJedisPool.java
        │  │  SortingParams.java
        │  │  Transaction.java
        │  │  Tuple.java
        │  │  ZParams.java
        │  │  
        │  ├─commands
        │  │      AdvancedBinaryJedisCommands.java
        │  │      AdvancedJedisCommands.java
        │  │      BasicCommands.java
        │  │      BasicRedisPipeline.java
        │  │      BinaryJedisClusterCommands.java
        │  │      BinaryJedisCommands.java
        │  │      BinaryRedisPipeline.java
        │  │      BinaryScriptingCommands.java
        │  │      BinaryScriptingCommandsPipeline.java
        │  │      ClusterCommands.java
        │  │      ClusterPipeline.java
        │  │      Commands.java
        │  │      JedisClusterBinaryScriptingCommands.java
        │  │      JedisClusterCommands.java
        │  │      JedisClusterScriptingCommands.java
        │  │      JedisCommands.java
        │  │      MultiKeyBinaryCommands.java
        │  │      MultiKeyBinaryJedisClusterCommands.java
        │  │      MultiKeyBinaryRedisPipeline.java
        │  │      MultiKeyCommands.java
        │  │      MultiKeyCommandsPipeline.java
        │  │      MultiKeyJedisClusterCommands.java
        │  │      ProtocolCommand.java
        │  │      RedisPipeline.java
        │  │      ScriptingCommands.java
        │  │      ScriptingCommandsPipeline.java
        │  │      SentinelCommands.java
        │  │      
        │  ├─exceptions
        │  │      InvalidURIException.java
        │  │      JedisAskDataException.java
        │  │      JedisClusterCrossSlotException.java
        │  │      JedisClusterException.java
        │  │      JedisClusterMaxRedirectionsException.java
        │  │      JedisConnectionException.java
        │  │      JedisDataException.java
        │  │      JedisException.java
        │  │      JedisMovedDataException.java
        │  │      JedisRedirectionException.java
        │  │      
        │  └─params
        │      │  Params.java
        │      │  
        │      ├─geo
        │      │      GeoRadiusParam.java
        │      │      
        │      ├─set
        │      │      SetParams.java
        │      │      
        │      └─sortedset
        │              ZAddParams.java
        │              ZIncrByParams.java
        │              
        └─util
                ClusterNodeInformation.java
                ClusterNodeInformationParser.java
                Hashing.java
                IOUtils.java
                JedisByteHashMap.java
                JedisClusterCRC16.java
                JedisURIHelper.java
                KeyMergeUtil.java
                MurmurHash.java
                Pool.java
                RedisInputStream.java
                RedisOutputStream.java
                SafeEncoder.java
                Sharded.java
                ShardInfo.java
                Slowlog.java

Jedis.java

技术分享
我们每次使用jedis都会初始化一个jedis对象,对下面代码肯定不会陌生:

public class Jedis extends BinaryJedis implements JedisCommands, MultiKeyCommands,
    AdvancedJedisCommands, ScriptingCommands, BasicCommands, ClusterCommands, SentinelCommands {

  protected JedisPoolAbstract dataSource = null;

  public Jedis() {
    super();
  }

  public Jedis(final String host) {
    super(host);
  }

  public Jedis(final String host, final int port) {
    super(host, port);
  }
............

Jedis对象调用父类BinaryJedis构造器:

public class BinaryJedis implements BasicCommands, BinaryJedisCommands, MultiKeyBinaryCommands,
        AdvancedBinaryJedisCommands, BinaryScriptingCommands, Closeable {
    protected Client client = null;
    protected Transaction transaction = null;
    protected Pipeline pipeline = null;

    public BinaryJedis() {
        client = new Client();
    }

    public BinaryJedis(final String host) {
        URI uri = URI.create(host);
        if (uri.getScheme() != null && uri.getScheme().equals("redis")) {
            initializeClientFromURI(uri);
        } else {
            client = new Client(host);
        }
    }

    public BinaryJedis(final String host, final int port) {
        client = new Client(host, port);
    }

    public BinaryJedis(final String host, final int port, final int timeout) {
        client = new Client(host, port);
        client.setConnectionTimeout(timeout);
        client.setSoTimeout(timeout);
    }

实际上,new Jedis()的初始化中。最重要的是new Client()这句代码。


Client 继承自 BinaryClient

public class Client extends BinaryClient implements Commands {

  public Client() {
    super();
  }

而BinaryClient又继承自Collection


public class BinaryClient extends Connection {
 ............
  private String password;

  private int db;

  private boolean isInWatch;

............
  public BinaryClient() {
    super();
  }
............

接着我们来看Collection代码:

    public class Connection implements Closeable {
    .....
    protected Connection sendCommand(final ProtocolCommand cmd, final String... args) {
        final byte[][] bargs = new byte[args.length][];
        for (int i = 0; i < args.length; i++) {
            // 对cmd判空并返回bytes
            bargs[i] = SafeEncoder.encode(args[i]);
        }
        return sendCommand(cmd, bargs);
    }

    protected Connection sendCommand(final ProtocolCommand cmd) {
        return sendCommand(cmd, EMPTY_ARGS);
    }

    protected Connection sendCommand(final ProtocolCommand cmd, final byte[]... args) {
        try {
            // 1.建立Socket连接
            connect();
            // 2.依照协议完毕IO操作,也就是命令的运行
            Protocol.sendCommand(outputStream, cmd, args);
            return this;
        } catch (JedisConnectionException ex) {
            /*
             * When client send request which formed by invalid protocol, Redis
             * send back error message before close connection. We try to read
             * it to provide reason of failure.
             */
            try {
                String errorMessage = Protocol.readErrorLineIfPossible(inputStream);
                if (errorMessage != null && errorMessage.length() > 0) {
                    ex = new JedisConnectionException(errorMessage, ex.getCause());
                }
            } catch (Exception e) {
                /*
                 * Catch any IOException or JedisConnectionException occurred
                 * from InputStream#read and just ignore. This approach is safe
                 * because reading error message is optional and connection will
                 * eventually be closed.
                 */
            }
            // Any other exceptions related to connection?

broken = true; throw ex; } } ... // 建立Sock连接 public void connect() { if (!isConnected()) { try { socket = new Socket(); // ->@wjw_add socket.setReuseAddress(true); socket.setKeepAlive(true); // Will monitor the TCP connection is // valid socket.setTcpNoDelay(true); // Socket buffer Whetherclosed, to // ensure timely delivery of data socket.setSoLinger(true, 0); // Control calls close () method, // the underlying socket is closed // immediately // <-@wjw_add socket.connect(new InetSocketAddress(host, port), connectionTimeout); socket.setSoTimeout(soTimeout); outputStream = new RedisOutputStream(socket.getOutputStream()); inputStream = new RedisInputStream(socket.getInputStream()); } catch (IOException ex) { broken = true; throw new JedisConnectionException(ex); } } } ...

在这里完毕了Socket连接。并返回这个Socket.
技术分享
每次我们使用Jedis去运行命令。都是这个持有Soket的client去运行的。


比方:

    /**
     * Get the value of the specified key. If the key does not exist null is
     * returned. If the value stored at key is not a string an error is returned
     * because GET can only handle string values.
     * <p>
     * Time complexity: O(1)
     * 
     * @param key
     * @return Bulk reply
     */
    @Override
    public String get(final String key) {
        checkIsInMultiOrPipeline();// 检查是否在事物中;检查是否是哟好难过管道技术
        client.sendCommand(Protocol.Command.GET, key);// 使用Socket进行IO操作,运行命令
        return client.getBulkReply();
    }

jedis除了继承的BinaryJedis完毕主要的IO操作。还实现了 JedisCommands, MultiKeyCommands, AdvancedJedisCommands,ScriptingCommands, BasicCommands, ClusterCommands, SentinelCommands
这几个可使用的命令的接口。

你能够參考redis自带的 unitTest,更深入的理解。


http://download.csdn.net/detail/lemon89/9407039

关于soTimeout 与 connectionTimeOut

我不多说了,这个链接解释非常清楚。

http://stackoverflow.com/questions/7360520/connectiontimeout-versus-sockettimeout

Jedis 源代码阅读一 —— Jedis

原文:http://www.cnblogs.com/llguanli/p/7403505.html

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