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| author | version | line-number | content |
|---|---|---|---|
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2.1 | 1 | get命令本质是调用了lookupKeyRead这个底层方法， |
| 2 | lookupKeyRead方法如下： | ||
| 3 | |||
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1.1 | 4 | {{plantuml}} |
| 5 | @startuml | ||
| 6 | start | ||
| 7 | |||
| 8 | |||
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2.1 | 9 | : lookupKeyReadWithFlags; |
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1.1 | 10 | |
| 11 | |||
| 12 | end | ||
| 13 | @enduml | ||
| 14 | {{/plantuml}} | ||
| 15 | |||
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2.1 | 16 | |
| 17 | lookupKeyReadWithFlags方法如下： | ||
| 18 | |||
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1.1 | 19 | {{plantuml}} |
| 20 | @startuml | ||
| 21 | start | ||
| 22 | |||
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8.1 | 23 | if(调用expireIfNeeded方法判断key是否过期)then(1) |
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12.1 | 24 | note left |
| 25 | 返回1代表已经过期 | ||
| 26 | endnote | ||
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8.1 | 27 | if(当前环境为主节点)then(yes) |
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9.1 | 28 | :返回null; |
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2.1 | 29 | stop |
| 30 | endif | ||
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1.1 | 31 | |
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8.1 | 32 | if(当前环境为从节点，并且命令为读的时候，那说明key过期是安全的)then(yes) |
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2.1 | 33 | :返回null; |
| 34 | stop | ||
| 35 | endif | ||
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10.1 | 36 | endif |
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1.1 | 37 | |
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11.1 | 38 | :调用lookupKey方法，查询value的值; |
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10.1 | 39 | if(返回值为空)then(yes) |
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7.1 | 40 | :缓存命中+1; |
| 41 | else(no) | ||
| 42 | :缓存非命中+1; | ||
| 43 | endif | ||
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5.1 | 44 | |
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2.1 | 45 | :返回查询的结果; |
| 46 | |||
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1.1 | 47 | end |
| 48 | @enduml | ||
| 49 | {{/plantuml}} |