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< > BotCompany Repo | #1032124 // SerializeComputations

JavaX fragment (include) [tags: use-pretranspiled]

Libraryless. Click here for Pure Java version (6332L/36K).

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sclass SerializeComputations<A, B> {
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  Map<A, Var<OKOrError<B>>> calculating = syncMap();
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  new MultiSetMap<A, Thread> waitingFor;
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  B get(A a, IF1<A, B> f) {
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    ret get(a, () -> f.get(a));
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  }
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  B get(A a, IF0<B> f) {
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    bool meCalc;
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    Var<OKOrError<B>> var;
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    synchronized {
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      var = calculating.get(a);
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      meCalc = var == null;
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      if (meCalc) {
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        var = new Var;
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        calculating.put(a, var);
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      } else
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        waitingFor.put(a, currentThread());
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    }
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    if (meCalc) {
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      OKOrError<B> b = okOrError(() -> f!);
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      var.set(b);
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      ret b.getMandatory();
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    } else {
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      try {
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        waitUntilNotNull(var);
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        ret var->getMandatory();
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      } finally {
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        synchronized {
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          waitingFor.remove(a, currentThread());
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          if (!waitingFor.containsKey(a))
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            calculating.remove(a);
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        }
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      }
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    }
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  }
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}

Author comment

Began life as a copy of #1032122

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Travelled to 4 computer(s): bhatertpkbcr, ekrmjmnbrukm, mqqgnosmbjvj, pyentgdyhuwx

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Snippet ID: #1032124
Snippet name: SerializeComputations
Eternal ID of this version: #1032124/11
Text MD5: dc0dfda23739f460c10dc6f43fd0c864
Transpilation MD5: 01c17d6a75ebecebb251938a01470071
Author: stefan
Category: javax / multi-threading
Type: JavaX fragment (include)
Public (visible to everyone): Yes
Archived (hidden from active list): No
Created/modified: 2021-11-01 23:22:20
Source code size: 930 bytes / 40 lines
Pitched / IR pitched: No / No
Views / Downloads: 145 / 338
Version history: 10 change(s)
Referenced in: [show references]