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seata-at-globallock.drawio
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<mxCell id="IiQ-Olb6a7n2lc8_pSmE-23" value="<div style="font-size: 11px;"><div>public boolean acquireLock(BranchSession branchSession, boolean autoCommit, <br>&nbsp; &nbsp; boolean skipCheckLock) throws TransactionException {</div><div>&nbsp; &nbsp; ...</div><div><font color="#007fff">&nbsp; &nbsp; <b>// lockKey 由“表名:主键值”组成，主键值可能有多个使用“,”连接，还可能有多个表:主键值，使用“;”连接</b></font></div><div>&nbsp; &nbsp; String lockKey = branchSession.<b>getLockKey</b>();</div><div>&nbsp; &nbsp; ...</div><div><font color="#007fff"><b>&nbsp; &nbsp; // 解析全部 "表名:主键值“ 结合分支会话信息组成一组行锁</b></font></div><div>&nbsp; &nbsp; List&lt;RowLock&gt; locks = <b>collectRowLocks</b>(branchSession);</div><div>&nbsp; &nbsp; if (CollectionUtils.isEmpty(locks)) {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; return true;</div><div>&nbsp; &nbsp; }</div><div><b><font color="#007fff">&nbsp; &nbsp; // DataBaseLockManager 初始化时创建了&nbsp;DataBaseLocker</font></b></div><div>&nbsp; &nbsp; return <b>getLocker</b>(branchSession).<b>acquireLock</b>(<b>locks</b>, autoCommit, skipCheckLock);</div><div>}</div></div>" style="rounded=1;whiteSpace=wrap;html=1;align=left;arcSize=4;fillColor=#dae8fc;strokeColor=#6c8ebf;fontSize=11;" vertex="1" parent="1">
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<mxCell id="IiQ-Olb6a7n2lc8_pSmE-25" value="<p style="margin:0px;margin-top:4px;text-align:center;"><b>RowLock</b><br></p><hr size="1"><p style="margin:0px;margin-left:4px;"><b><font color="#007fff">行锁</font></b></p><p style="margin:0px;margin-left:4px;"><br></p><p style="margin:0px;margin-left:4px;">private String xid;</p><p style="margin:0px;margin-left:4px;">private Long transactionId;</p><p style="margin:0px;margin-left:4px;">//</p><p style="margin:0px;margin-left:4px;">private Long branchId;</p><p style="margin:0px;margin-left:4px;">//</p><p style="margin:0px;margin-left:4px;">private String resourceId;</p><p style="margin:0px;margin-left:4px;"><font color="#007fff">// 表名</font></p><p style="margin:0px;margin-left:4px;">private String tableName;</p><p style="margin:0px;margin-left:4px;"><font color="#007fff">// 主键值</font></p><p style="margin:0px;margin-left:4px;">private String pk;</p><p style="margin:0px;margin-left:4px;"><font color="#007fff">//&nbsp;</font></p><p style="margin:0px;margin-left:4px;">private String <b>rowKey</b>;</p><p style="margin:0px;margin-left:4px;">private String feature;</p><hr size="1"><p style="margin:0px;margin-left:4px;"><br></p>" style="verticalAlign=top;align=left;overflow=fill;fontSize=12;fontFamily=Helvetica;html=1;whiteSpace=wrap;" vertex="1" parent="1">
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<mxCell id="IiQ-Olb6a7n2lc8_pSmE-26" value="<p style="margin:0px;margin-top:4px;text-align:center;"><b>AbstractLocker</b><br></p><hr size="1"><p style="margin:0px;margin-left:4px;"><br></p><p style="margin:0px;margin-left:4px;">protected static final String LOCK_SPLIT = "^^^";<br></p><hr size="1"><p style="margin:0px;margin-left:4px;"><br></p>" style="verticalAlign=top;align=left;overflow=fill;fontSize=12;fontFamily=Helvetica;html=1;whiteSpace=wrap;" vertex="1" parent="1">
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<mxCell id="IiQ-Olb6a7n2lc8_pSmE-27" value="<p style="margin:0px;margin-top:4px;text-align:center;"><b>Locker</b><br></p><hr size="1"><p style="margin:0px;margin-left:4px;"></p><p style="margin:0px;margin-left:4px;">boolean acquireLock(List&lt;RowLock&gt; rowLock) ;<br></p><p style="margin:0px;margin-left:4px;">boolean acquireLock(List&lt;RowLock&gt; rowLock, boolean autoCommit, boolean skipCheckLock);<br></p><p style="margin:0px;margin-left:4px;">boolean releaseLock(List&lt;RowLock&gt; rowLock);<br></p><p style="margin:0px;margin-left:4px;">boolean releaseLock(String xid, Long branchId);<br></p><p style="margin:0px;margin-left:4px;">boolean releaseLock(String xid);<br></p><p style="margin:0px;margin-left:4px;">...</p>" style="verticalAlign=top;align=left;overflow=fill;fontSize=12;fontFamily=Helvetica;html=1;whiteSpace=wrap;fillColor=#d5e8d4;strokeColor=#82b366;" vertex="1" parent="1">
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<mxCell id="IiQ-Olb6a7n2lc8_pSmE-35" value="<div style=""><div>public boolean acquireLock(List&lt;LockDO&gt; lockDOs, boolean autoCommit, boolean skipCheckLock) {</div><div>&nbsp; &nbsp; ...</div><div><font color="#007fff">&nbsp; &nbsp; // LockDO 去重</font></div><div>&nbsp; &nbsp; if (lockDOs.size() &gt; 1) {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; lockDOs = lockDOs.stream().filter(LambdaUtils.<b>distinctByKey</b>(LockDO::getRowKey)).collect(Collectors.toList());</div><div>&nbsp; &nbsp; }</div><div>&nbsp; &nbsp; try {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; conn = lockStoreDataSource.getConnection();</div><div>&nbsp; &nbsp; &nbsp; &nbsp; if (originalAutoCommit = conn.getAutoCommit()) {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; conn.setAutoCommit(false);</div><div>&nbsp; &nbsp; &nbsp; &nbsp; }</div><div>&nbsp; &nbsp; &nbsp; &nbsp; List&lt;LockDO&gt; unrepeatedLockDOs = lockDOs;</div><div><br></div><div><font color="#007fff"><b>&nbsp; &nbsp; &nbsp; &nbsp; //获取锁前校验，需要先校验这些锁是否已经存在，有任意一个锁存在都不能获取锁</b></font></div><div>&nbsp; &nbsp; &nbsp; &nbsp; if (!skipCheckLock) {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; boolean canLock = true;</div><div><font color="#007fff">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // 从锁的数据表中查询这些锁是否已经存在</font></div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; String checkLockSQL = LockStoreSqlFactory.getLogStoreSql(dbType).<b>getCheckLockableSql</b>(lockTable, lockDOs.size());</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ...</div><div>&nbsp; &nbsp; &nbsp; &nbsp; }</div><div><br></div><div><font color="#007fff"><b>&nbsp; &nbsp; &nbsp; &nbsp; // lockDOs中的锁都不存在，则获取这些锁，就是将它们插入到数据表</b></font></div><div>&nbsp; &nbsp; &nbsp; &nbsp; if (unrepeatedLockDOs.size() == 1) {&nbsp; <font color="#007fff">// 只有一个锁对象</font></div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; LockDO lockDO = unrepeatedLockDOs.get(0);</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if (!doAcquireLock(conn, lockDO)) {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ...</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; conn.<b>rollback</b>(); <font color="#007fff">// 可能插入前其他事务将锁插入了数据表，则当前事务获取锁失败，还需要当前事务将已经插入的锁回滚</font></div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return false;</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }</div><div>&nbsp; &nbsp; &nbsp; &nbsp; } else {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if (!doAcquireLocks(conn, unrepeatedLockDOs)) {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ...</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; conn.rollback();</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return false;</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }</div><div>&nbsp; &nbsp; &nbsp; &nbsp; }</div><div>&nbsp; &nbsp; &nbsp; &nbsp; conn.commit();</div><div>&nbsp; &nbsp; &nbsp; &nbsp; return true;</div><div>&nbsp; &nbsp; } catch (SQLException e) {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; throw new StoreException(e);</div><div>&nbsp; &nbsp; } finally {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; ... 释放连接，恢复自动提交 ...</div><div>&nbsp; &nbsp; }</div><div>}</div></div>" style="rounded=1;whiteSpace=wrap;html=1;align=left;arcSize=2;fontSize=11;" vertex="1" parent="1">
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<mxCell id="IiQ-Olb6a7n2lc8_pSmE-37" value="<div style=""><div>protected boolean doAcquireLock(Connection conn, LockDO lockDO) {</div><div>&nbsp; &nbsp; PreparedStatement ps = null;</div><div>&nbsp; &nbsp; try {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; String insertLockSQL = LockStoreSqlFactory.<b>getLogStoreSql</b>(dbType)<br><span style="white-space: pre;">	</span>&nbsp; &nbsp; .getInsertLockSQL(lockTable);</div><div>&nbsp; &nbsp; &nbsp; &nbsp; ps = conn.prepareStatement(insertLockSQL);</div><div>&nbsp; &nbsp; &nbsp; &nbsp; ps.setString(1, lockDO.getXid());</div><div>&nbsp; &nbsp; &nbsp; &nbsp; ps.setLong(2, lockDO.getTransactionId());</div><div>&nbsp; &nbsp; &nbsp; &nbsp; ps.setLong(3, lockDO.getBranchId());</div><div>&nbsp; &nbsp; &nbsp; &nbsp; ps.setString(4, lockDO.getResourceId());</div><div>&nbsp; &nbsp; &nbsp; &nbsp; ps.setString(5, lockDO.getTableName());</div><div>&nbsp; &nbsp; &nbsp; &nbsp; ps.setString(6, lockDO.getPk());</div><div>&nbsp; &nbsp; &nbsp; &nbsp; ps.setString(7, lockDO.<b>getRowKey</b>());</div><div>&nbsp; &nbsp; &nbsp; &nbsp; ps.setInt(8, LockStatus.Locked.getCode());</div><div>&nbsp; &nbsp; &nbsp; &nbsp; return ps.executeUpdate() &gt; 0;</div><div>&nbsp; &nbsp; } catch (SQLException e) {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; if (e instanceof SQLIntegrityConstraintViolationException) {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return false;</div><div>&nbsp; &nbsp; &nbsp; &nbsp; }</div><div>&nbsp; &nbsp; &nbsp; &nbsp; throw new StoreException(e);</div><div>&nbsp; &nbsp; } finally {</div><div>&nbsp; &nbsp; &nbsp; &nbsp; IOUtil.close(ps);</div><div>&nbsp; &nbsp; }</div><div>}</div></div>" style="rounded=1;whiteSpace=wrap;html=1;align=left;arcSize=2;fillColor=#fff2cc;strokeColor=#d6b656;fontSize=11;" vertex="1" parent="1">
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<mxCell id="IiQ-Olb6a7n2lc8_pSmE-39" value="<font color="#007fff"><b>insert into&nbsp; #lock_table# (xid, transaction_id, branch_id, resource_id, table_name, pk, row_key, gmt_create, gmt_modified,status) </b><br><b>values (?, ?, ?, ?, ?, ?, ?, now(), now(), ?);&nbsp;<br></b><br><b>获取锁原理就是基于主键唯一索引（row_key）进行插入，插入成功获取锁成功，插入失败获取锁失败，和Redis set nx 原理一样。</b><br></font>" style="text;html=1;align=left;verticalAlign=middle;resizable=0;points=[];autosize=1;strokeColor=none;fillColor=none;" vertex="1" parent="1">
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<mxCell id="IiQ-Olb6a7n2lc8_pSmE-40" value="<div><font color="#007fff">CREATE TABLE IF NOT EXISTS `<b>lock_table</b>`</font></div><div><font color="#007fff">(</font></div><div><font color="#007fff">&nbsp; &nbsp; `row_key`&nbsp; &nbsp; &nbsp; &nbsp; VARCHAR(128) NOT NULL,</font></div><div><font color="#007fff">&nbsp; &nbsp; `xid`&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; VARCHAR(128),</font></div><div><font color="#007fff">&nbsp; &nbsp; `transaction_id` BIGINT,</font></div><div><font color="#007fff">&nbsp; &nbsp; `branch_id`&nbsp; &nbsp; &nbsp; BIGINT&nbsp; &nbsp; &nbsp; &nbsp;NOT NULL,</font></div><div><font color="#007fff">&nbsp; &nbsp; `resource_id`&nbsp; &nbsp; VARCHAR(256),</font></div><div><font color="#007fff">&nbsp; &nbsp; `table_name`&nbsp; &nbsp; &nbsp;VARCHAR(32),</font></div><div><font color="#007fff">&nbsp; &nbsp; `pk`&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;VARCHAR(36),</font></div><div><font color="#007fff">&nbsp; &nbsp; `status`&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;TINYINT&nbsp; &nbsp; &nbsp; NOT NULL DEFAULT '0' COMMENT '0:locked ,1:rollbacking',</font></div><div><font color="#007fff">&nbsp; &nbsp; `gmt_create`&nbsp; &nbsp; &nbsp;DATETIME,</font></div><div><font color="#007fff">&nbsp; &nbsp; `gmt_modified`&nbsp; &nbsp;DATETIME,</font></div><div><font color="#007fff">&nbsp; &nbsp; <b>PRIMARY KEY</b> (`<b>row_key</b>`),</font></div><div><font color="#007fff">&nbsp; &nbsp; KEY `idx_status` (`status`),</font></div><div><font color="#007fff">&nbsp; &nbsp; KEY `idx_branch_id` (`branch_id`),</font></div><div><font color="#007fff">&nbsp; &nbsp; KEY `idx_xid` (`xid`)</font></div><div><font color="#007fff">) ENGINE = InnoDB</font></div><div><font color="#007fff">&nbsp; DEFAULT CHARSET = utf8mb4;</font></div>" style="text;html=1;align=left;verticalAlign=middle;resizable=0;points=[];autosize=1;strokeColor=none;fillColor=none;" vertex="1" parent="1">
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<mxCell id="IiQ-Olb6a7n2lc8_pSmE-41" value="<font color="#007fff">即删除锁的行记录</font>" style="text;html=1;align=center;verticalAlign=middle;resizable=0;points=[];autosize=1;strokeColor=none;fillColor=none;" vertex="1" parent="1">
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<mxCell id="IiQ-Olb6a7n2lc8_pSmE-42" value="<div style=""><div>protected LockDO convertToLockDO(RowLock rowLock) {</div><div>&nbsp; &nbsp; LockDO lockDO = new LockDO();</div><div>&nbsp; &nbsp; lockDO.setBranchId(rowLock.getBranchId());</div><div>&nbsp; &nbsp; lockDO.setPk(rowLock.getPk());</div><div>&nbsp; &nbsp; lockDO.setResourceId(rowLock.getResourceId());</div><div><font style="" color="#007fff"><b>&nbsp; &nbsp; // 锁记录的主键是 resourceId^^^tableName^^^pk 拼接成的，比如&nbsp;</b><br><b>&nbsp; &nbsp; //&nbsp;</b></font><font color="#007fff"><b>jdbc:mysql://127.0.0.1:13306/seata_product^^^product^^^1</b></font></div><div>&nbsp; &nbsp; lockDO.<b>setRowKey</b>(<b>getRowKey</b>(rowLock.getResourceId(), rowLock.getTableName(), rowLock.getPk()));</div><div>&nbsp; &nbsp; lockDO.setXid(rowLock.getXid());</div><div>&nbsp; &nbsp; lockDO.setTransactionId(rowLock.getTransactionId());</div><div>&nbsp; &nbsp; lockDO.setTableName(rowLock.getTableName());</div><div>&nbsp; &nbsp; return lockDO;</div><div>}</div></div>" style="rounded=1;whiteSpace=wrap;html=1;align=left;arcSize=3;fontSize=11;fillColor=#fff2cc;strokeColor=#d6b656;" vertex="1" parent="1">
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<mxCell id="IiQ-Olb6a7n2lc8_pSmE-44" value="<b>获取锁原理就是基于主键唯一索引（row_key）进行插入，<br>插入成功获取锁成功，插入失败获取锁失败，和Redis set nx 原理一样。</b>" style="text;html=1;align=left;verticalAlign=middle;resizable=0;points=[];autosize=1;strokeColor=none;fillColor=none;" vertex="1" parent="1">
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